Imprinting apparatus, imprinting method, and article manufacturing method

Abstract

To provide a technique advantageous for achieving both the accuracy of alignment between a mold and a substrate and throughput.SOLUTION: An imprint device is provided which performs imprint processing including an alignment step of performing alignment between a substrate and a mold with the mold in contact with an imprint material on the substrate, and a curing step of curing the imprint material by light irradiation after the alignment step. The imprint device has: a first irradiation unit that performs first light irradiation for the imprint material on the substrate before bringing the mold into contact with the imprint material on the substrate for the alignment step; a second irradiation unit that performs second light irradiation for the imprint material on the substrate in the alignment step; and a third irradiation unit that performs third light irradiation for the imprint material on the substrate in the curing step. An amount of exposure resulting from the first light irradiation is determined based on an amount of exposure resulting from the second light irradiation.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] As one of the lithography apparatuses for mass production of semiconductor devices and the like, an imprint apparatus has been put into practical use. The imprint apparatus forms a pattern on a substrate by curing an imprint material supplied on the substrate while bringing a mold into contact with the imprint material and then separating the mold from the cured imprint material.

[0003] In the manufacture of semiconductor devices, a plurality of layers each having a pattern such as an electric circuit are formed on a substrate. Therefore, it is necessary to perform alignment with high precision when forming a pattern on each layer so that the electric circuits are successfully connected between the layers.

[0004] In an imprint apparatus, alignment is performed in a state where the imprint material on the substrate is in contact with the mold. It has been found that it is difficult to ensure the desired alignment accuracy if the viscosity of the imprint material on the substrate is too low during alignment. Therefore, it has been proposed to perform preliminary exposure for irradiating light to at least a part of the imprint material on the substrate in order to increase the viscosity of the imprint material on the substrate when performing alignment (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The amount of light required to increase the viscosity of the imprint material can vary depending on the material of the imprint material, its thickness, the atmosphere in the imprint space, and the like. When increasing the amount of light for increasing the viscosity, it is necessary to increase the irradiation time of the light or increase the illuminance. When increasing the irradiation time of the light, the time required for alignment becomes longer, and the throughput may decrease. When increasing the illuminance, problems such as difficulty in realization due to the upper limit in optical design or shortening of the life of the light source may occur.

[0007] The present invention provides a technique advantageous for achieving both the alignment accuracy between a mold and a substrate and throughput.

Means for Solving the Problems

[0008] According to one aspect of the present invention, there is provided an imprint apparatus that performs an imprint process including an alignment step of aligning a substrate and a mold in a state where the mold is in contact with an imprint material on the substrate, and a curing step of curing the imprint material by light irradiation after the alignment step, the imprint apparatus having: a first irradiation unit that performs first light irradiation on the imprint material to increase the viscosity of the imprint material before bringing the mold into contact with the imprint material; a second irradiation unit that performs second light irradiation on the imprint material in the alignment step to increase the viscosity of the imprint material; and a third irradiation unit that performs third light irradiation on the imprint material in the curing step. A control unit that determines a first exposure amount of the first light irradiation and a second exposure amount of the second light irradiation so that a viscosity resistance of the imprint material in the pattern region of the substrate after the first light irradiation and the second light irradiation does not exceed a first threshold value; There is provided an imprint apparatus characterized by having the above.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a technique advantageous for achieving both the alignment accuracy between a mold and a substrate and throughput.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 12

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and redundant explanations are omitted.

[0012] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system with the direction parallel to the surface of the substrate being the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are referred to as the X-direction, Y-direction, and Z-direction, respectively, and the rotations around the X-axis, Y-axis, and Z-axis are referred to as θX, θY, and θZ, respectively. Control or drive with respect to the X-axis, Y-axis, and Z-axis means control or drive in the direction parallel to the X-axis, Y-axis, and Z-axis, respectively. Positioning means controlling the position, posture, or inclination. Alignment may include controlling the position, posture, or inclination of at least one of the substrate and the mold.

[0013] <First Embodiment> FIG. 1 is a diagram showing the configuration of an imprint apparatus IS according to the first embodiment. The imprint apparatus IS is a lithography apparatus used in the manufacturing process of articles such as semiconductor devices. The imprint apparatus IS performs an imprint process for forming a pattern on a substrate. The imprint process may include at least the following steps. (a) A contact step of bringing the imprint material supplied onto the substrate into contact with the pattern region of the mold. (b) A curing step of curing the imprint material by applying energy for curing to the imprint material. (c) A mold release step of separating the mold from the cured imprint material.

[0014] By the imprint process, the uneven pattern of the pattern region of the mold is transferred onto the substrate to form a pattern of a cured product.

[0015] As the imprint material, a curing composition (sometimes also referred to as an uncured resin) that cures when energy for curing is applied is used. As the energy for curing, electromagnetic waves are used. As the electromagnetic waves, for example, light such as infrared rays, visible light, and ultraviolet rays whose wavelength is selected from the range of 10 nm or more and 1 mm or less is used. Irradiating the imprint material with light that causes a curing reaction is called exposure.

[0016] The curable composition can be a photocurable composition that cures upon irradiation with light. The photocurable composition contains at least a polymerizable compound and a photopolymerization initiator, and may 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 release agent, a surfactant, an antioxidant, a polymer component, and the like.

[0017] The arrow in Fig. 1 indicates the conveyance path of the substrate to be processed. First, in an imprint material coating apparatus RC, which is an external apparatus of the imprint apparatus IS, an imprint material is supplied in advance to all of a plurality of shot regions of the substrate. The supply of the imprint material can be performed by coating the imprint material. The coating of the imprint material is performed, for example, by spin-coating the imprint material on the entire surface to be processed of the substrate. Next, the substrate coated with the imprint material is conveyed to a pre-exposure unit 10 (first irradiation unit) in the imprint apparatus IS. The pre-exposure unit 10 performs first pre-exposure on the imprint material coated on the substrate. In this specification, the operation of irradiating light on the imprint material before bringing the mold into contact with the imprint material is called "pre-exposure". The substrate that has undergone the first pre-exposure is conveyed to an imprint unit 20 in the imprint apparatus IS. The imprint unit 20 performs an imprint process on the conveyed substrate.

[0018] FIG. 2 is a diagram showing the configuration of the preliminary exposure unit 10. The preliminary exposure unit 10 includes a substrate holding unit 11 that holds the substrate 1 and an illumination unit 12 that irradiates preliminary exposure light. The preliminary exposure unit 10 is connected to the control unit 9. The control unit 9 controls the operation of the preliminary exposure unit 10. The substrate holding unit 11 includes a holding unit such as a vacuum chuck or an electrostatic chuck and holds the substrate 1. The illumination unit 12 has a light source and an illumination optical system (not shown) and is configured to irradiate light over the entire surface of the substrate 1 held by the substrate holding unit 11. The illumination unit 12 may irradiate the light after diffusing it, or may include a number of LED light sources arranged to cover the substrate 1. Thereby, the preliminary exposure unit 10 can perform preliminary exposure on the imprint materials on all of the plurality of shot regions of the substrate at once. Alternatively, the preliminary exposure unit 10 may be configured to perform preliminary exposure by scanning illumination light over the plurality of shot regions of the substrate. The scanning exposure can be performed, for example, by driving the substrate holding unit 11 in the XY directions.

[0019] The light irradiated by the illumination unit 12 includes light having a wavelength at which the imprint material undergoes a curing reaction. The irradiation amount of the light from the illumination unit 12 can be changed by adjusting at least either the illuminance or the irradiation time of the illumination unit 12. The first preliminary exposure is performed on the imprint material applied to the substrate 1, but is not performed with an exposure amount sufficient to completely cure the imprint material.

[0020] The preliminary exposure unit 10 may have a configuration in which the irradiation amount is variable in the radial direction of the substrate 1. Alternatively, the preliminary exposure unit 10 may have a configuration in which the irradiation amount is variable for each shot region (imprint region) of the substrate 1.

[0021] FIG. 3 is a diagram showing the configuration of the imprint unit 20. The imprint unit 20 may include a substrate positioning unit 21 that holds and positions the substrate 1, a mold positioning unit 22 that holds and positions the mold 2, a curing unit 23, a viscosity adjustment unit 24, and a measurement unit 25. The imprint unit 20 is connected to the control unit 9 and its operation is controlled by the control unit 9.

[0022] The mold 2 has, for example, a rectangular outer shape and can be made of a material that is transparent to ultraviolet light, such as quartz. The mold 2 has a pattern region PR on the surface facing the substrate 1. In the pattern region PR, a three-dimensional concave-convex pattern to be transferred to the imprint material on the substrate 1 is formed. The pattern region PR is also called a mesa, and is formed as a convex portion of several tens to several hundreds of μm so that the area of the mold 2 other than the pattern region PR does not come into contact with the substrate 1.

[0023] The substrate 1 is made of, for example, a semiconductor (e.g., silicon, compound semiconductor), glass, ceramics, metal, resin, etc. The substrate 1 may have one or more layers on a base material. In this case, the base material is made of, for example, a semiconductor, glass, ceramics, metal, resin, etc. If necessary, an adhesion layer may be provided on the substrate 1 to improve adhesion between the imprint material and the substrate 1. A plurality of shot regions (imprint regions) are formed on the substrate 1.

[0024] The mold positioning unit 22 may include a mold holding unit 22a and a mold driving mechanism 22b. The mold holding unit 22a holds the mold 2 by, for example, vacuum suction force or electrostatic force. The mold driving mechanism 22b is a driving system for changing the distance between the mold 2 and the substrate 1. The mold driving mechanism 22b drives (moves) the mold 2 in the Z direction by driving the mold holding unit 22a. The mold driving mechanism 22b includes an actuator such as a linear motor or an air cylinder, and drives the mold holding unit 22a holding the mold 2. The mold driving mechanism 22b is configured to drive the mold 2 (mold holding unit 22a) about multiple axes (for example, three axes: the Z axis, the θX axis, and the θY axis). To achieve high-precision positioning of the mold 2, the mold driving mechanism 22b may include multiple driving systems, such as a coarse driving system and a fine driving system. Furthermore, the mold driving mechanism 22b may have a function to drive the mold 2 not only in the Z direction but also in the X direction, Y direction, and θZ direction, and a function to correct the tilt of the mold 2.

[0025] The substrate positioning unit 21 may include a substrate holding unit 21a that holds the substrate 1 and a substrate driving mechanism 21b. The substrate holding unit 21a holds the substrate 1, for example, by vacuum suction or electrostatic force. The substrate driving mechanism 21b drives (moves) the substrate 1 in the X and Y directions by driving the substrate holding unit 21a. The substrate driving mechanism 21b includes an actuator such as a linear motor or an air cylinder, and drives the substrate holding unit 21a that holds the substrate 1. The substrate driving mechanism 21b may be configured to drive the substrate 1 (substrate holding unit 21a) about multiple axes (for example, three axes: the X axis, the Y axis, and the θZ axis, or preferably six axes: the X axis, the Y axis, the Z axis, the θX axis, the θY axis, and the θZ axis). The substrate driving mechanism 21b may include multiple driving systems, such as a coarse driving system and a fine driving system. The substrate driving mechanism 21b may have a function of driving the substrate 1 in the Z direction or the θZ direction, and a function of correcting the tilt of the substrate 1.

[0026] The measurement unit 25 detects the alignment marks provided on the substrate 1 and the mold 2, respectively, and measures the relative displacement between the substrate 1 and the mold 2 in the X and Y directions. The measurement unit 25 is composed of a measurement light source, a camera, an optical system, etc. for detecting the alignment marks. In this specification, when the term "relative displacement" is simply used hereafter, it refers to the relative displacement (misalignment) between the substrate 1 and the mold 2 in the X and Y directions.

[0027] The mold positioning unit 22 and the substrate positioning unit 21 are mechanisms that drive the mold 2 or the substrate 1 so as to adjust the relative position, relative attitude, and relative tilt in the XY plane between the mold 2 and the substrate 1, and determine the relative position between the mold 2 and the substrate 1. The mold positioning unit 22 and the substrate positioning unit 21 can be used to perform alignment to reduce error components related to the relative shift and rotation between the pattern area PR of the mold 2 and the shot area of the substrate 1. During the alignment operation, the viscosity of the imprint material is adjusted using the viscosity adjustment unit 24. Details will be described later.

[0028] Furthermore, the mold positioning unit 22 and the substrate positioning unit 21 have a mechanism for driving the mold 2 or the substrate 1 so as to change the Z-direction positions of the substrate 1 and the mold 2, and adjust the relative position, relative attitude, and relative inclination in the Z direction between the mold 2 and the substrate 1. The adjustment of the relative position in the Z direction by the mold positioning unit 22 and / or the substrate positioning unit 21 includes driving for the contact between the imprint material on the substrate 1 and the mold 2, and the separation of the cured imprint material (pattern of the cured product) from the mold 2.

[0029] The viscosity adjustment unit 24 (second irradiation unit) irradiates light including a wavelength at which a curing reaction of the imprint material occurs through the mold 2 in a state where the imprint material above the shot region of the substrate 1 is in contact with the pattern region PR of the mold 2 (second preliminary exposure). Thereby, the viscosity of the imprint material is increased and the vibration component of the relative displacement is reduced. In the present embodiment, the viscosity adjustment unit 24 has, for example, a light source that emits light (exposure light such as ultraviolet light) for curing the imprint material. Further, the viscosity adjustment unit 24 may include an optical element for adjusting the light emitted from the light source to appropriate light in the imprint process. The viscosity adjustment unit 24 can adjust the illuminance, irradiation distribution, etc., for example, using a DMD (Digital Micromirror Device). The DMD includes a plurality of mirror elements, and the irradiation region can be adjusted by individually controlling the surface directions of the plurality of mirror elements.

[0030] The curing unit 23 (third irradiation unit) cures the imprint material by supplying or irradiating energy for curing the imprint material (for example, light such as ultraviolet light). Specifically, the curing unit 23 performs light irradiation (main exposure) through the mold 2 in a state where the imprint material above the shot region of the substrate 1 is in contact with the pattern region PR of the mold 2. Thereby, a pattern made of the cured product of the imprint material is formed. In the present embodiment, the curing unit 23 has, for example, a light source that emits light (exposure light such as ultraviolet light) for curing the imprint material. Further, the curing unit 23 may include an optical element for adjusting the light emitted from the light source to appropriate light in the imprint process.

[0031] The control unit 9 controls the preliminary exposure unit 10 and the imprint unit 20, and controls the overall (operation) of the imprint apparatus IS. Further, the control unit 9 controls each part of the imprint unit 20 to perform an imprint process. The control unit 9 can be configured by, for example, 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 computer in which a program is incorporated, or a combination of all or part of these.

[0032] FIG. 4 is a flowchart showing an imprint method of the imprint apparatus IS according to the first embodiment. FIG. 4 shows a process of forming a pattern in a plurality of shot regions of the substrate 1. However, the description of the loading of the mold 2 into the mold holding part 22a and the unloading of the mold 2 from the mold holding part 22a is omitted. The processes described in FIG. 4 are controlled by the control unit 9.

[0033] In step S101 (substrate loading step), the control unit 9 controls a substrate transfer device (not shown) to transfer the substrate 1 coated with the imprint material in the imprint material coating device RC to the substrate holding part 11 of the preliminary exposure unit 10. In step S102 (first preliminary exposure step), the control unit 9 controls the preliminary exposure unit 10 to perform a first preliminary exposure (first light irradiation) on the imprint material on the substrate 1. FIG. 11(a) shows an example of the exposure amount by the first preliminary exposure. The horizontal axis represents the X coordinate of the shot region, and the vertical axis represents the exposure amount. The first curing threshold E1 is a threshold of the exposure amount by a predetermined first preliminary exposure. The first preliminary exposure is performed so as not to exceed this first curing threshold E1. The first curing threshold E1 (that is, the exposure amount by the first light irradiation) is determined based on the exposure amount (exposure amount by the second light irradiation) of the second preliminary exposure by the viscosity adjustment unit 24 in the alignment step (S106). The adjustment of the exposure amount by the first preliminary exposure will be described later.

[0034] In step S103 (substrate transfer step), the control unit 9 controls the substrate transfer device to transfer the substrate 1 from the pre-exposure unit 10 to the substrate holding unit 21a of the imprint unit 20. In step S104 (movement step), the control unit 9 drives the substrate positioning unit 3 so that the shot area of the substrate 1 faces the pattern area PR of the mold 2. In step S105 (contact step), the control unit 9 drives the mold positioning unit 4 to bring the pattern area PR of the mold 2 into contact with the imprint material on the substrate 1. Step S106 (alignment step) includes a second pre-exposure step. In step S106, the control unit 9 controls the viscosity adjustment unit 24 to perform a second pre-exposure (second light irradiation) on the imprint material on the substrate to adjust the viscosity of the imprint material. FIG. 11(b) shows an example of the integrated exposure amount by the second pre-exposure. The second curing threshold E2 is a threshold of the integrated exposure amount of the first pre-exposure and the second pre-exposure determined in advance to effectively increase the viscosity of the imprint material. The second pre-exposure is performed so as not to exceed this second curing threshold E2. Thereafter, the control unit 9 controls the mold positioning unit 22 and the substrate positioning unit 21 to align the substrate 1 and the mold 2.

[0035] In step S107 (curing step), the control unit 9 controls the curing unit 23 to perform main exposure (third light irradiation) on the imprint material to cure the imprint material. FIG. 11(c) shows an example of the integrated exposure amount by the main exposure. The third curing threshold E3 is a threshold of the integrated exposure amount of the first pre-exposure, the second pre-exposure, and the main exposure determined in advance assuming that the imprint material is sufficiently cured to be separable from the mold. The main exposure is stopped when it exceeds this third curing threshold E3.

[0036] In step S108 (demolding step), the control unit 9 drives the mold positioning unit 4 to separate the mold 2 from the substrate 1. In step S109, the control unit 9 determines whether there is a next shot area. If there is a next shot area, the process returns to step S104, and imprinting is repeated for the next shot area. If there is no next shot area, the process proceeds to step S110. In step S110 (substrate unloading step), the control unit 9 controls the substrate transport device to unload the substrate 1 from the substrate holding unit 3a, and the operation according to the imprint method is completed.

[0037] The relative displacement in the alignment step of step S106 will be described with reference to FIG. 5. The purpose of the alignment step is to bring the relative displacement close to zero. For simplicity, only the relative displacement in the X direction will be described here. FIG. 5(a) shows a graph with time on the horizontal axis and relative displacement on the vertical axis. FIG. 5(b) shows a graph in which only the vibration component of the relative displacement shown in FIG. 5(a) is enlarged and displayed. FIG. 5(c) shows a graph with time on the horizontal axis and illuminance by the viscosity adjustment unit 24 on the vertical axis.

[0038] Time 0 is the start time of step S106. Time t1 is the start time of viscosity adjustment (second light irradiation) by the viscosity adjustment unit 24, and time t2 is the end time. When the substrate positioning unit 21 is controlled so that the relative displacement decreases from time 0 to time t1, the relative displacement decreases as shown in FIG. 5(a), but as shown in FIG. 5(b), a vibration component remains at time t1. The vibration component remains because the vibration cannot be completely tracked due to variations in alignment measurement, the measurement frequency, the responsiveness of the substrate positioning unit 21, and so on. Therefore, in the alignment step, the control unit 9 controls the viscosity adjustment unit 24 to irradiate light onto the imprint material on the substrate to increase the viscosity of the imprint material, thereby increasing the viscous resistance between the substrate 1 and the mold 2 and reducing the relative displacement.

[0039] As shown in FIG. 5(c), when the viscosity adjustment unit 24 irradiates light (viscosity adjustment) between time t1 and time t2, as shown in FIG. 5(b), the amplitude of the relative displacement decreases from time t1 to time t2. In the present embodiment, since the first preliminary exposure is performed in step S102, the exposure amount of the second preliminary exposure (the irradiation amount by the second light irradiation) by the viscosity adjustment unit 24 in step S106 (alignment step) can be reduced. The reduction of the irradiation amount can be achieved by shortening the irradiation time or reducing the illuminance while keeping the irradiation time unchanged. Without the first preliminary exposure in step S102, the viscosity of the imprint material does not increase immediately even when the viscosity adjustment unit 24 irradiates light. The reason is, for example, that air is dissolved in the imprint material on the substrate 1, and the curing reaction is delayed due to oxygen inhibition. Alternatively, usually, an SOC film or the like is formed on the substrate 1 for a subsequent etching process, and the imprint material is applied thereon. The SOC film contains oxygen in the air and the like, and the curing reaction is delayed due to oxygen inhibition. On the other hand, according to the present embodiment, the viscosity of the imprint material can be quickly increased by performing light irradiation in advance by the first preliminary exposure. As an effect of shortening the irradiation time of the light for the second preliminary exposure by the viscosity adjustment unit 24, the time required for alignment in the imprint unit 20 can be shortened. The preliminary exposure unit 10 can perform the first preliminary exposure of the substrate to be processed next while the imprint process is being performed in the imprint unit 20. That is, the imprint apparatus IS can execute the imprint process on the substrate and the first preliminary exposure on the imprint material on another substrate in parallel. As a result, the throughput of the imprint apparatus IS is improved by the amount of time for alignment reduction. Also, as an effect when the illuminance is reduced while keeping the irradiation time unchanged, it can be mentioned that the performance degradation of the light source of the viscosity adjustment unit 24 can be suppressed (the life is prolonged).

[0040] Referring to FIG. 6, a method for adjusting the exposure amount of the first preliminary exposure by the preliminary exposure unit 10 will be described. FIG. 6 shows a flowchart of an imprint process including the step of adjusting the exposure amount of the first preliminary exposure.

[0041] In step S201 (substrate carrying-in step), the control unit 9 controls the substrate carrying device to carry the substrate 1, on which the imprint material has been applied in the imprint material application device RC, into the substrate holding unit 11 of the pre-exposure unit . In step S202 (first pre-exposure step), the control unit 9 controls the pre-exposure unit 10 to perform a first pre-exposure on the imprint material on the substrate 1. Here, the exposure dose of the first pre-exposure may be distributed across the surface of the substrate 1. For example, the imprint material on the substrate 1 may have radial film thickness variations due to being applied by a method such as spin coating in the imprint material application device RC. Additionally, the substrate 1 may have radial warpage due to underlying processes. As a result, the optimal exposure dose of the first pre-exposure, particularly at the outer periphery of the substrate 1, may differ from that at the center of the substrate 1. In consideration of these factors, it is advisable to adjust the exposure dose of the first pre-exposure (the amount of irradiation by the first light) in the radial direction of the substrate 1. Specifically, the film thickness of the spin-coated imprint material is measured in advance using a measuring device or calculated by simulation. From the results, the control unit 9 obtains the relationship between the radial position of the substrate 1 and the film thickness, and determines the illuminance according to the film thickness. For example, the illuminance is set to be proportional to the film thickness. This allows the control unit 9 to control the exposure amount of the first preliminary exposure for each shot area in accordance with the film thickness distribution of the imprint material on the substrate 1. This widens the process margin for film thickness variations, which is advantageous in terms of productivity.

[0042] In step S203 (imprint step), the control unit 9 performs imprint processing on each of the multiple shot areas on the substrate 1. Step S203 corresponds to steps S103 to S109 in FIG. In step S204 (substrate unloading step), the control unit 9 controls the substrate transport device to unload the substrate 1 from the substrate holder 3a. In step S205 (data collection step), the control unit 9 collects data related to the alignment step in the imprint step of step S203. The data to be collected is data on the evaluation value related to the alignment step. The evaluation value can be, for example, the magnitude (such as amplitude) of the vibration component of the relative displacement. Alternatively, the evaluation value may be a measured value of the viscous resistance of the imprint material when the substrate 1 is moved by the substrate positioning unit 22 in the alignment step. Generally, since there are a plurality of shot regions on the substrate 1, the evaluation value can be obtained for the number of shot regions.

[0043] In step S206, the control unit 9 determines whether to change the exposure amount of the first pre-exposure based on the data collected in step S205. The determination criterion is whether the viscosity of the imprint material becomes high before the viscosity adjustment of the imprint material in the alignment step and whether the viscous resistance exceeds the reference value when driving the substrate positioning unit 4 in the alignment step. When the viscous resistance does not exceed the reference value, it may be determined how much margin there is with respect to the reference value of the viscous resistance.

[0044] If the viscous resistance is too high, the mold 2 may be deformed during the alignment drive, and the overlay accuracy may decrease. Therefore, the reference value of the viscous resistance can be set according to the required overlay accuracy. In one example, the reference value is set so that the viscous resistance is 1 N or less. When determining by the magnitude (amplitude) of the vibration component, it may be calculated and compared how much smaller the amplitude is compared to the case without the first pre-exposure. For example, when the amplitude is less than half of the amplitude without the first pre-exposure, it is determined that the viscosity is high. When it is determined that there is no need to change the exposure amount by the first pre-exposure, the process ends, and when it is determined to change the exposure amount by the first pre-exposure, the process proceeds to step S207.

[0045] As described above, in step S205, an evaluation value is obtained for each shot area. Statistical values such as the average, maximum, and minimum of these evaluation values can be used for the judgment. In one example, the control unit 9 may make a judgment for each shot area and adjust the exposure amount of the first preliminary exposure (the irradiation amount of the first light irradiation) by the preliminary exposure unit 10 for each shot area.

[0046] In step S207 (adjustment step), the control unit 9 adjusts the exposure amount of the first preliminary exposure to be performed next in step S202 based on the data collected in step S205. For example, if it is determined in step S206 that the viscous resistance force has a margin relative to the reference value (for example, is lower than the reference value by a predetermined amount or more), the control unit 9 increases the exposure amount of the first preliminary exposure. On the other hand, if it is determined in step S206 that the viscous resistance force exceeds the reference value, the control unit 9 reduces the exposure amount of the first preliminary exposure.

[0047] In this way, the imprint apparatus IS performs the first preliminary exposure using the preliminary exposure unit 10, and then adjusts the viscosity, thereby allowing the imprint material to be cured in a state where the relative displacement between the substrate 1 and the mold 2 is reduced. This makes it possible to achieve both high alignment accuracy and high throughput.

[0048] Second Embodiment An imprint apparatus IS according to the second embodiment will be described below. Matters not mentioned in the second embodiment will be in accordance with the first embodiment. In the first embodiment, the substrate 1 is loaded into the imprint apparatus IS after the imprint material has been applied to the substrate 1 by the imprint material application apparatus RC. In contrast, in the second embodiment, the imprint material is supplied onto the substrate 1 within the imprint apparatus IS.

[0049] FIG. 7 is a diagram showing the configuration of an imprint apparatus IS according to the second embodiment. The arrows in FIG. 7 indicate the conveyance path of the substrate to be processed. The imprint apparatus IS includes an imprint material supply unit 30. The imprint material supply unit 30 supplies an imprint material onto the loaded substrate. The substrate onto which the imprint material has been supplied by the imprint material supply unit 30 is conveyed to a pre-exposure unit 40 (first irradiation unit). The pre-exposure unit 40 performs first pre-exposure on the imprint material supplied onto the substrate. The substrate that has undergone the first pre-exposure is conveyed to the imprint unit 20. The imprint unit 20 performs an imprint process on the loaded substrate.

[0050] FIG. 8 is a diagram showing the configuration of the imprint apparatus IS. The imprint apparatus IS may include an imprint material supply unit 30, a pre-exposure unit 40, an imprint unit 20, and a control unit 9. The imprint unit 20 includes a substrate positioning unit 21 that holds and positions the substrate 1, a mold positioning unit 22 that holds and positions the mold 2, a curing unit 23, a viscosity adjustment unit 24, and a measurement unit 25. Since the components of these imprint units 20 are the same as those in the first embodiment, the description thereof is omitted.

[0051] The imprint material supply unit 30 drops the imprint material onto the substrate 1 by, for example, an inkjet method. When supplying the imprint material, the substrate 1 is disposed directly below the imprint material supply unit 30 by the substrate positioning unit 21. The supply of the imprint material is continuously performed for a plurality of shot regions, and then, an imprint process is performed for each shot region on the plurality of shot regions onto which the imprint material has been supplied.

[0052] The preliminary exposure unit 40 has a light source and an illumination optical system for performing the first preliminary exposure, and is configured to irradiate light onto the substrate 1. The light irradiated by the preliminary exposure unit 40 includes light having a wavelength at which the imprint material undergoes a curing reaction. The irradiation amount of light in the first preliminary exposure can be changed by adjusting the illuminance and irradiation time of the light source of the preliminary exposure unit 40. The first preliminary exposure is performed on the imprint material applied to the substrate 1, but is not performed with an exposure amount sufficient to completely cure the imprint material.

[0053] FIG. 9 is a flowchart showing an imprint method of the imprint apparatus IS according to the second embodiment. FIG. 9 shows a process of forming a pattern in a plurality of shot regions of the substrate 1. However, the description of loading the mold 2 into the mold holding portion 22a and unloading the mold 2 from the mold holding portion 22a is omitted. The processes described in FIG. 9 are controlled by the control unit 9.

[0054] In step S301 (substrate loading step), the control unit 9 controls a substrate transfer device (not shown) to load the substrate 1 into the substrate holding portion 21a. In step S302 (supply step), the control unit 9 controls the substrate positioning unit 21 and the imprint material supply unit 30 to supply (drop) the imprint material to a predetermined sub-region of the substrate 1. The predetermined sub-region is, for example, a shot region arranged in a row in the X direction. FIG. 10 shows an example of the sub-region of the substrate 1. FIG. 10(a) shows the layout of a plurality of shot regions of the substrate 1. As shown in FIG. 10(a), typically, for a circular substrate 1, each shot region has a rectangular shape except for the outer peripheral portion. Here, a shot region arranged in a row in the X direction is taken as one sub-region. FIG. 10(b) shows an example in which a plurality of shot regions are divided into eight columns of sub-regions (first to eighth supply regions) arranged in the X direction. In step S302, the imprint material is supplied to one selected sub-region.

[0055] In process S303 (the first preliminary exposure process), the control unit 9 controls the preliminary exposure unit 40 to perform the first preliminary exposure (the first light irradiation) on the imprint material on the sub-region of the substrate 1. At this time, a masking member may be arranged so that exposure light does not leak to other sub-regions. Alternatively, instead of using such a masking member, the preliminary exposure unit 40 may be provided with a laser light source and a DMD in order to obtain sharp light-shielding characteristics at the sub-region edge.

[0056] Since processes S304 to S308 are the same as processes S104 to S108 of the first embodiment, the descriptions thereof are omitted. In process S309, the control unit 9 determines whether there is a next shot region. If there is a next shot region, the process proceeds to process S310, and if there is no next shot region, the process proceeds to process S311. In process S310, it is determined whether the supply of the imprint material for the next shot region has already been completed. If the supply of the imprint material to the next shot region has been completed, the process returns to process S304 to execute the imprint for the next shot region. If the supply of the imprint material to the next shot region has not been performed yet, the process returns to process S302 to supply the imprint material to the sub-region including the next shot region. In process S311 (substrate unloading process), the control unit 9 controls the substrate transfer device to unload the substrate 1 from the substrate holding unit 21a and terminate the operation according to the imprint method.

[0057] As described above, the imprint apparatus IS of the second embodiment processes the substrate 1 by repeatedly supplying the imprint material, pre-exposing, and imprinting. By simultaneously pre-exposing multiple shot regions within a sub-region to which the imprint material has been supplied, processing time can be shortened compared to adjusting the viscosity of each shot region after the contact process. Furthermore, the pre-exposure unit 40 can be positioned close to the substrate 1, rather than being located far from the substrate above the Z axis of the imprint unit 50, as is the case with the viscosity adjustment unit 24. This is advantageous in terms of optical design, allowing for a wider irradiation range and higher output from the light source of the pre-exposure unit 40. This allows for a shorter time required to adjust the viscosity of the imprint material by using both the pre-exposure unit 40 and the viscosity adjustment unit 24, compared to adjusting the viscosity of the imprint material using only the viscosity adjustment unit 24. This improves the throughput of the imprint apparatus IS.

[0058] <Embodiment of an article manufacturing method> The pattern of the cured product formed using the imprinting apparatus is used permanently on at least a portion of various articles, or temporarily when manufacturing various articles. Examples of articles include electrical circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of electrical circuit elements include volatile or nonvolatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGAs. Examples of molds include molds for imprinting.

[0059] The pattern of the cured product may be used as it is as at least a part of a component of the article, or may be used temporarily as a resist mask, which is removed after etching or ion implantation in a substrate processing step.

[0060] Next, a method for manufacturing an article will be described. In step SA of FIG. 12, a substrate 1z such as a silicon substrate on which a workpiece 2z such as an insulator is formed on the surface is prepared. Subsequently, 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 droplet-shaped imprint materials 3z are applied onto the substrate is shown.

[0061] In step SB of FIG. 12, an imprint mold 4z is opposed to the substrate with the side on which the concavo-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 is applied and the mold 4z are brought into contact with each other and pressure is applied. The imprint material 3z is filled in the gap between the mold 4z and the workpiece 2z. When light is irradiated through the mold 4z as energy for curing in this state, the imprint material 3z cures.

[0062] In step SD of FIG. 12, after curing the imprint material 3z, when the mold 4z and the substrate 1z are separated from each other, a pattern of the cured product of the imprint material 3z is formed on the substrate 1z. This pattern of the cured product has a shape in which the concave portion of the mold corresponds to the convex portion of the cured product and the convex portion of the mold corresponds to the concave portion of the cured product. That is, the concavo-convex pattern of the mold 4z is transferred to the imprint material 3z.

[0063] In step SE of FIG. 12, when etching is performed using the pattern of the cured product as an etching mask, the portion of the surface of the workpiece 2z where no cured product remains or where the cured product remains thinly is removed to form a groove 5z. In step SF of FIG. 12, when the pattern of the cured product is removed, an article having a groove 5z formed on the surface of the workpiece 2z can be obtained. Here, the pattern of the cured product is removed, but it may not be removed after processing and may be used, for example, as a film for interlayer insulation included in a semiconductor element or the like, that is, as a component of the article.

[0064] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention.

Explanation of Reference Numerals

[0065] IS: Imprinting device, RC: Imprinting material application device, 10: Pre-exposure unit, 20: Imprinting unit

Claims

1. An imprint apparatus that performs an imprint process including an alignment process of aligning a substrate and a mold in a state where the mold is in contact with an imprint material on the substrate, and a curing process of curing the imprint material by light irradiation after the alignment process, a first irradiation unit that performs first light irradiation on the imprint material to increase the viscosity of the imprint material before bringing the mold into contact with the imprint material, a second irradiation unit that performs second light irradiation on the imprint material in the alignment process to increase the viscosity of the imprint material, a third irradiation unit that performs third light irradiation on the imprint material in the curing process, a control unit that determines a first exposure amount of the first light irradiation and a second exposure amount of the second light irradiation so that a viscosity resistance of the imprint material in a pattern region of the substrate after the first light irradiation and the second light irradiation does not exceed a first threshold value, characterized by comprising.

2. The substrate is a substrate on which an imprint material has been previously supplied to all of a plurality of shot regions in an external device, The first irradiation unit performs the first light irradiation on all of the imprint materials in all of the plurality of shot regions in a batch, The imprint apparatus according to claim 1, characterized in that.

3. The substrate is a substrate on which an imprint material has been previously supplied to all of a plurality of shot regions in an external device, The first light irradiation is performed by scanning light from the first irradiation unit over the plurality of shot regions, The imprint apparatus according to claim 1, characterized in that.

4. The imprint process on the substrate and the first light irradiation on an imprint material on another substrate are executed in parallel, The imprint apparatus according to claim 2 or 3, characterized in that.

5. The control unit controls the irradiation amount by the first light irradiation for each shot region according to the film thickness distribution on the substrate, The imprint apparatus according to any one of claims 2 to 4, characterized in that.

6. The control unit adjusts the irradiation amount by the first light irradiation based on data of an evaluation value related to the alignment process for each shot region, The imprint apparatus according to any one of claims 1 to 4, characterized in that.

7. The imprint apparatus according to claim 6, wherein the evaluation value is the magnitude of the vibration component of the relative displacement between the mold and the shot area in the alignment process.

8. The imprint apparatus according to claim 6, wherein the evaluation value is a measured value of the viscous resistance of the imprint material in the alignment process.

9. The imprint apparatus according to claim 7 or 8, wherein when the statistical value of the evaluation value for each shot area exceeds a reference value, the control unit reduces the irradiation amount by the first light irradiation, and when the statistical value is lower than the reference value by a predetermined amount or more, the control unit increases the irradiation amount by the first light irradiation.

10. a substrate positioning unit that holds and moves the substrate; a supply unit that individually supplies an imprint material to a plurality of shot areas on the substrate; and a control unit that controls the imprint process, and the control unit, for each sub-region of the substrate, controls the substrate positioning unit and the supply unit so that an imprint material is supplied onto a plurality of shot areas included in the sub-region, and performs the imprint process for each of the plurality of shot areas included in the sub-region. The imprint apparatus according to claim 1, wherein the imprint apparatus is characterized by the above.

11. An imprint method of forming a pattern on a substrate by curing an imprint material by light irradiation with the mold in contact with the imprint material on the substrate, a pre-exposure step of performing first light irradiation on the imprint material before bringing the mold into contact with the imprint material to increase the viscosity of the imprint material; an alignment step of performing second light irradiation on the imprint material with the mold in contact with the imprint material, and aligning the substrate and the mold in a state where the first light irradiation and the second light irradiation are performed so that the viscous resistance of the imprint material in the pattern area of the substrate does not exceed a first threshold value; and a curing step of performing third light irradiation on the imprint material after the alignment to increase the viscosity of the imprint material. The imprint method is characterized by having the above steps.

12. A step of forming a pattern on a substrate using the imprint apparatus according to any one of claims 1 to 10; a step of processing the substrate on which the pattern is formed; having, and manufacturing an article from the processed substrate, characterized in that it is an article manufacturing method.

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