Molding device and article manufacturing method

Abstract

The present invention provides a molding device and an article manufacturing method. There is provided a molding device for molding a composition on a substrate by using a mold, the molding device being characterized by comprising: a control unit that controls a process of bringing a first surface of the mold into contact with the composition to form a film of the composition between the first surface and the substrate; and a deformation unit that applies a force to a second surface of the mold on the opposite side of the first surface to deform the first surface into a convex shape on the substrate side, wherein the control unit controls the deformation unit such that, during the process, the force applied by the deformation unit to the second surface after the first surface and the composition come into contact with each other is greater than the force applied by the deformation unit to the second surface before the first surface and the composition come into contact with each other.

Description

Technical Field

[0001] The present invention relates to a molding apparatus and an article manufacturing method. Background Art

[0002] Imprint technology is a technology capable of transferring a nanoscale fine pattern (concavo-convex pattern), and this technology has attracted attention as one of the large-scale production lithography technologies for semiconductor devices, magnetic storage media, etc. Imprint technology is a technology in which a nanoscale fine pattern (concavo-convex pattern) is transferred onto a substrate such as a silicon wafer and a glass plate by using a mold having a pattern formed thereon as an original plate.

[0003] An imprint apparatus using imprint technology is a molding apparatus that forms an imprint material as a composition on a substrate by using a mold. More specifically, the imprint apparatus forms a pattern of the imprint material on the substrate by curing the imprint material in a state where the imprint material on the substrate is in contact with the mold and separating the cured imprint material from the mold. The curing method of the imprint material includes a photocuring method and a thermal curing method. The photocuring method suppresses an increase in the pattern transfer time based on temperature control or a decrease in the pattern size accuracy due to temperature change, and thus is suitable for the manufacture of semiconductor devices and magnetic storage media.

[0004] In an imprint apparatus, when the imprint material on the substrate is brought into contact with the mold, air bubbles are sometimes mixed in the imprint material. When the imprint material is cured while air bubbles are mixed in the imprint material in this way, a pattern is not formed in the portion where the air bubbles are present, resulting in a defect (unfilled defect).

[0005] Therefore, a technique has been proposed in which when the imprint material on the substrate is brought into contact with the mold, the mold (its pattern surface) is deformed (bent) into a convex shape with respect to the substrate and then the mold is restored to its original shape (planar shape) (see Patent Documents 1 to 4). This technique makes it possible to reduce the air bubbles mixed in the imprint material on the substrate by pushing out the air bubbles present between the substrate (the imprint material on the substrate) and the mold to the outside.

[0006] A technique has also been proposed in which when separating the mold from the imprint material cured on the substrate, the mold is deformed or the substrate is deformed by changing the suction force (adsorption pressure) for sucking the substrate, thereby reducing defects in the pattern formed on the substrate (see Patent Documents 5 and 6).

[0007] Citation List

[0008] Patent Documents

[0009] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-536591

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2009-518207

[0011] Patent Document 3: Japanese Patent No. 4391420

[0012] Patent Document 4: Japanese Patent No. 5139421

[0013] Patent Document 5: U.S. Patent No. 2006-172553

[0014] Patent Document 6: Japanese Patent Application Laid-Open No. 2009-517882 Summary of the Invention

[0015] Technical Problem

[0016] Recently, there has been a demand for further improving the productivity (throughput) of an imprinting apparatus. For example, consider a case where while a mold is deformed into a convex shape with respect to a substrate, the mold is brought into contact with an imprinting material on the substrate so that the imprinting material diffuses from the center of a shot region toward its periphery. In this case, by increasing the diffusion speed of the imprinting material, the time required for a step (dynamic diffusion step) before transferring to a filling step of filling a mold (its concave portion) with the imprinting material on the substrate or the filling step is shortened, thereby improving productivity. However, note that since the time required for the filling step generally depends on the time required for an alignment step of aligning (positioning) the mold and the substrate, it is necessary to shorten the time required for the dynamic diffusion step. However, as a result of intensive studies by the present inventors, it has been found that unnecessarily shortening the time required for the dynamic diffusion step will increase unfilled defects, which leads to a reduction in productivity.

[0017] The present invention provides a molding apparatus that is advantageous in terms of improving productivity.

[0018] Solution to the Problem

[0019] A molding apparatus according to an aspect of the present invention is a molding apparatus that forms a composition on a substrate by using a mold, and is characterized by including: a control unit configured to control a process of forming a film of the composition between a first surface of the mold and the substrate by bringing the first surface of the mold into contact with the composition; and a deformation unit configured to deform the first surface into a convex shape with respect to the substrate side by applying a force to a second surface of the mold on the opposite side of the first surface, wherein the control unit controls the deformation unit in the process such that a force applied to the second surface by the deformation unit after contact between the first surface and the composition is greater than a force applied to the second surface by the deformation unit before contact between the first surface and the composition.

[0020] Advantageous Effects of the Invention

[0021] The present invention can provide a molding apparatus that is advantageous, for example, in terms of improving productivity.

[0022] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. Note that in all the drawings, the same reference numerals denote the same or similar components. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings incorporated in and forming a part of the specification illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0024] Figure 1 is a schematic view showing the arrangement of an imprinting apparatus according to one aspect of the present invention.

[0025] Figure 2 is a view showing an example of the arrangement of a drive unit for an imprint head.

[0026] Figure 3 is a view showing a state in which the table area of the mold is deformed convex with respect to the substrate side.

[0027] Figure 4 is a flowchart for explaining a general imprinting process.

[0028] Figure 5 is a view showing experimental results obtained by observing how unfilled defects occur.

[0029] Figure 6 is a view showing the contact state between the imprinting material on the substrate and the mold and an image obtained by an observation unit.

[0030] Figure 7 is for explaining in detail Figure 6 each of the states shown.

[0031] Figure 8 is for explaining in detail Figure 6 each of the states shown.

[0032] Figure 9 is a view showing the results obtained by calculating the force that causes the mold to fall off the mold chuck.

[0033] Figure 10 is a view showing the results obtained by calculating the relationship between the thickness of the core out portion of the mold and the maximum stress.

[0034] Figure 11 is a view schematically showing the state of contact between the mold and the substrate.​​​​​​​​​​​

[0035] Figure 12 is a graph showing the relationship between the pressure applied to the core-removing part of the mold and the combined force obtained by combining the suction force and the dropping force.

[0036] Figure 13 is a graph showing the relationship between the pressure applied to the core-removing part of the mold and the maximum stress.

[0037] Figure 14 is a graph for explaining the basic control line profile.

[0038] Figure 15 is a graph for explaining the control line profile in this embodiment.

[0039] Figure 16 is a graph showing the relationship between the pressure applied to the core-removing part of the mold and the maximum deformation amount of the mold.

[0040] Figure 17 is a graph for explaining the evaluation method of evaluating the curvature of the mold.

[0041] Figure 18 is a graph showing the result of evaluating the curvature of the mold by using the basic control line profile shown in Figure 14 .

[0042] Figure 19 is a graph showing the result of evaluating the curvature of the mold by using the control line profile according to this embodiment shown in Figure 15 .

[0043] Figure 20 is a graph showing the pressure control line profile.

[0044] Figure 21 is a graph showing the result of simulating the pressure control line profile shown in Figure 20 .

[0045] Figure 22 is a graph showing the pressure control line profile.

[0046] Figure 23 is a graph showing the simulation result of the pressure control line profile shown in Figure 22 .

[0047] Figure 24 is a graph showing the distribution map of the number of gas molecules captured between the mold and the imprinting material on the substrate.

[0048] Figure 25 is a graph showing the distribution map of the number of gas molecules captured between the mold and the imprinting material on the substrate. ​​​​​​​​​​​​​​

[0049] Figure 26 is a figure for explaining a method of manufacturing an article.

[0050] Figure 27 is for explaining Figure 1 the case where the imprinting apparatus shown is used as a planarizing apparatus. DETAILED DESCRIPTION

[0051] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. In the embodiments, a plurality of features are described, but the invention does not necessarily require all of these features, and a plurality of such features can be appropriately combined. Further, in the drawings, the same reference numerals are given to the same or similar configurations, and redundant descriptions thereof are omitted.

[0052] Figure 1 is a schematic view showing the arrangement of an imprinting apparatus IMP as an aspect of the present invention. The imprinting apparatus IMP is a lithography apparatus used in the lithography step of manufacturing steps for semiconductor devices, magnetic storage media, liquid crystal display elements, etc. and forms a pattern on a substrate. The imprinting apparatus IMP functions as a molding apparatus that performs a molding process of molding an imprint material as a composition on a substrate by using a mold. In the present embodiment, the imprinting apparatus IMP brings the imprint material supplied onto the substrate into contact with the mold and supplies curing energy to the imprint material, thereby forming a pattern of a cured material, and the pattern of the mold is transferred onto the cured material. Note that the mold is also referred to as a template or a master.

[0053] A material (curable composition) that is cured by receiving curing energy is used as the imprint material. Examples of the curing energy used are electromagnetic waves, heat, etc. For example, infrared light, visible light, ultraviolet light, etc. selected from the wavelength range of 10 nm (including 10 nm) to 1 mm (including 1 mm) are used as the electromagnetic waves.

[0054] The curable composition is a composition that is cured by light irradiation or heating. The photocurable composition cured by light irradiation contains at least a polymerizable compound and a photoinitiator, and may contain a non-polymerizable compound or a solvent as needed. The non-polymerizable compound is at least one material selected from the group including a sensitizer, a hydrogen donor, an internal release agent, a surfactant, an antioxidant, a polymer component, etc.

[0055] ​​The imprinting material can be applied onto the substrate in a film shape by a spin coater or a slit coater. The imprinting material can be applied onto the substrate in a droplet shape or in an island shape or a film shape formed by connecting a plurality of droplets by using a liquid ejection head. The viscosity of the imprinting material (viscosity at 25°C) is, for example, from 1 mPa·s (including 1 mPa·s) to 100 mPa·s (including 100 mPa·s).

[0056] Glass, ceramics, metals, semiconductors, resins, etc. are used as the substrate, and if necessary, a member made of a material different from that of the substrate can be formed on the surface of the substrate. More specifically, examples of the substrate include: silicon wafers, semiconductor compound wafers, quartz glass, etc.

[0057] As Figure 1 As shown, the imprinting device IMP includes: a substrate stage 3, a substrate chuck 5, an imprinting head 6, a pressure adjustment unit 7, and a mold chuck 9. In addition, the imprinting device IMP includes: a relay optical system 12, a band-pass filter 13, an observation unit 14, a first measurement unit 15, a second measurement unit 16, a control unit 18, a storage unit 19, and an irradiation system 30.

[0058] In the specification and the drawings, directions will be indicated on an XYZ coordinate system, where the direction parallel to the surface of the substrate 4 is defined as the X-Y plane. The directions parallel to the X-axis, Y-axis, and Z-axis of the XYZ coordinate system are the X direction, Y direction, and Z direction, respectively, and the rotations about the X-axis, Y-axis, and Z-axis are θX, θY, and θZ, respectively. The control or drive (movement) with respect to the X-axis, Y-axis, and Z-axis means the control or drive with respect to the directions parallel to the X-axis, Y-axis, and Z-axis, respectively. In addition, the control or drive (movement) with respect to the θX-axis, θY-axis, and θZ-axis means the control or drive with respect to the rotations about the axes parallel to the X-axis, Y-axis, and Z-axis, respectively.

[0059] The mold 1 has a rectangular outer shape and is formed of a quartz substrate. The mold 1 has a table area 2 in the central portion of the first surface 1a on the substrate side, and a pattern (concavo-convex pattern) to be transferred onto the substrate 4 is formed on the table area 2. The table area 2 is formed to be higher than its surrounding area, that is, is formed to have a stepped structure to prevent the area other than the table area 2 from contacting the substrate 4 when forming a pattern of the imprinting material on the substrate. The mold 1 has a core removal portion 8 (recessed structure) as a cylindrical recess in the second surface 1b on the opposite side of the first surface 1a including the table area 2. The core removal portion 8 is also called a cavity and is generally formed such that the center of the core removal portion 8 overlaps with the center of the table area 2.

[0060] The imprint head 6 holds the mold 1 by, for example, vacuum chucking or electrostatic chucking of the mold chuck 9 of the mold 1. The imprint head 6 serves as a pressing portion that brings the mold 1 held by the mold chuck 9 into contact with the imprint material on the substrate and presses the mold 1 against the imprint material. The imprint head 6 includes a drive unit that drives (moves) the mold chuck 9. As Figure 2 shown, the drive unit includes three-axis drive systems D21, D22, and D23. Figure 2 FIG. is a diagram showing an example of the arrangement of the drive unit for the imprint head 6. The drive systems D21, D22, and D23 are constituted by, for example, actuators capable of independently driving in the Z direction. The position and attitude (state) of the imprint head 6 can be measured (observed) in real time by various types of sensors (for example, a height sensor and a force sensor (not shown) incorporated in the imprint head 6) provided for the imprint device IMP.

[0061] The pressure adjustment unit 7 adjusts the pressure of the core removal portion 8 provided in the mold 1. The purpose of providing the core removal portion 8 is that when the mold 1 is brought into contact with the imprint material on the substrate, by deforming the mold 1, more specifically, by deforming the table region 2 into a convex shape with respect to the substrate side, the region in contact with the imprint material gradually expands from the central portion of the table region 2. More specifically, by causing the pressure adjustment unit 7 to increase the pressure of the core removal portion 8 to be greater than the external pressure, the table region 2 of the mold 1 can be deformed into a convex shape with respect to the substrate side. In this way, the pressure adjustment unit 7 serves as a deformation unit that deforms the first surface 1a into a convex shape with respect to the substrate side by applying a force to the second surface 1b on the opposite side of the first surface 1a of the mold 1. In the present embodiment, the pressure adjustment unit 7 deforms the table region 2 (first surface 1a) into a convex shape with respect to the substrate side by adjusting the pressure of the core removal portion 8 of the mold 1 to apply a force to the core removal portion 8 (second surface 1b). By deforming the table region 2 of the mold 1 into a convex shape with respect to the substrate side, the gas present between the mold 1 (table region 2) and the substrate 4 (imprint material) can be pushed out to the outside (outer periphery) to reduce the bubbles mixed in the imprint material on the substrate.

[0062] In the present embodiment, the relay optical system 12 is placed inside the imprint head 6, and the band-pass filter 13 and the irradiation system 30 are placed above the imprint head 6. When the imprint material on the substrate comes into contact with the mold 1, the irradiation system 30 cures the imprint material by irradiating the imprint material on the substrate with light (for example, ultraviolet light) that has passed through the band-pass filter 13 and the relay optical system 12.

[0063] The observation unit 14 is placed above the imprint head 6. The observation unit 14 observes the table area 2 of the mold 1 and the projection area of the substrate 4 through the band-pass filter 13 and the relay optical system 12. More specifically, the observation unit 14 observes the state in which the imprint material on the substrate is diffused by the mold 1 or the interference fringes formed by the narrow gap between the mold 1 and the substrate 4, and obtains an observation image. The observation unit 14 also serves as an acquisition unit that acquires information on the increase in the contact area (contact region) between the mold 1 (table area 2) and the imprint material on the substrate.

[0064] The substrate stage 3 holds the substrate 4 by the substrate chuck 5 that vacuum-adsorbs or electrostatically adsorbs the substrate 4. The substrate stage 3 drives (moves) the substrate chuck 5 in the X direction and the Y direction so that imprint processing can be performed on the entire surface (all projection areas) of the substrate 4.

[0065] The substrate stage 3 is provided with a first measurement unit 15 that measures the height of the first surface 1a of the mold 1 on the substrate side, for example, the height of the table area 2. Therefore, the substrate stage 3 is moved so that the first measurement unit 15 passes under the mold 1, enabling the first measurement unit 15 to measure the shape (surface shape) or the amount of inclination of the table area 2 of the mold 1.

[0066] The imprint device IMP is also provided with a second measurement unit 16 that faces the substrate stage 3 and measures the height of the substrate 4. Therefore, the substrate stage 3 is moved so that the substrate 4 passes under the second measurement unit 16, enabling the measurement unit 16 to measure the shape (surface shape) or the amount of inclination of the substrate 4.

[0067] The control unit 18 is formed of an information processing device (computer) including a CPU and a memory, and controls the entire imprinting device IMP according to a program stored in the storage unit 19. The control unit 18 controls each unit of the imprinting device IMP to control the process of forming an imprint material film between the table region 2 (the first surface 1a) of the mold 1 and the substrate by bringing the table region 2 into contact with the imprint material (composition) on the substrate. In the present embodiment, the process of forming the imprint material film is an imprinting process of forming a pattern of the imprint material on each of a plurality of projection regions on the substrate. The control unit 18 can evaluate the imprinting process by analyzing the image obtained by the observation unit 14, and reflect the evaluation result in the imprinting process. For example, the control unit 18 obtains the measurement results (the surface shape and tilt amount of the table region 2 of the mold 1 and the surface shape and tilt amount of the substrate 4) obtained by the first measurement unit 15 and the second measurement unit 16, and checks the leveling state between the mold 1 and the substrate 4. Based on the leveling state between the mold 1 and the substrate 4, the control unit 18 controls the state (position and attitude) of the imprint head 6 and the state (shape) of the mold 1 through the imprint head 6 and the pressure adjustment unit 7.

[0068] A general imprinting process will be described in detail with reference to Figure 4 FIG. Figure 4 is a flowchart for explaining a general imprinting process. The imprinting process is usually performed while maintaining the leveling state between the mold 1 and the substrate 4 in parallel. More specifically, making the leveling state between the table region 2 of the mold 1 and the projection region of the substrate 4 parallel will achieve an ideal imprinting process. Therefore, the first measurement unit 15 (on the device) measures in advance the surface shape (position in the height direction (Z direction)) and tilt amount of the table region 2 of the mold 1, and the second measurement unit 16 globally measures in advance the surface shape and tilt amount of the substrate 4, thereby obtaining the leveling state between the table region 2 and the mold 1. In step S402, a target tilt position (target tilt position) of the mold 1 or the substrate 4 is set, and the gap amount between the table region 2 of the mold 1 and the substrate 4 is also set.

[0069] In step S404, as Figure 3 shown, by applying (applying) pressure to the core removal portion 8 of the mold 1 via the pressure adjustment unit 7, the table region 2 of the mold 1 bulges toward the substrate side and deforms into a convex shape. As described above, this operation is performed to suppress air bubbles from being trapped in the imprint material on the substrate when starting to bring the mold 1 into contact with the imprint material on the substrate. Note that the deformation amount of the table region 2 of the mold 1 is preset, that is, the value of the pressure applied to the core removal portion 8 of the mold 1 from the pressure adjustment unit 7. Figure 3 is a view showing a state in which the table region 2 of the mold 1 deforms into a convex shape with respect to the substrate side in the imprinting device IMP.

[0070] In step S406, a contact step of bringing the mold 1 into contact with the imprint material on the substrate is started. More specifically, the mold chuck 9 that holds the mold 1 is lowered in the Z direction with respect to the substrate 4 positioned in the X direction and the Y direction by the substrate stage 3, so that the central portion of the table area 2 of the mold 1 comes into contact with the imprint material on the substrate. Further, while maintaining this state, force control is performed to lower the mold chuck 9 in the Z direction until a predetermined force is set to spread the imprint material on the substrate over the entire table area 2 of the mold 1. At this time, the height (Z-direction position) control, tilt control, and force control of the mold 1 are implemented by controlling the driving of each of the drive systems D21, D22, and D23 that constitute the drive unit of the imprint head 6.

[0071] When the imprint material on the substrate has spread over the entire table area 2 of the mold 1, in step S408, the pressure of the core removal portion 8 of the mold 1 is lowered (decreased) by the pressure adjustment unit 7 to restore the shape of the table area 2 of the mold 1 to its original shape. In step S408, the leveling state between the mold 1 and the substrate 4 is finally made parallel. In step S410, the process proceeds to a filling step of filling the mold 1 with the imprint material on the substrate, and the leveling state between the mold 1 and the substrate 4 is maintained parallel within a predetermined period (until the mold 1 is filled with the imprint material on the substrate). Note that the steps before the transfer to the filling step, more specifically, the steps including step S406 and step S408, are also referred to as the dynamic diffusion steps.

[0072] In step S412, when the mold 1 is filled with the imprint material on the substrate, the irradiation system 30 cures the imprint material by irradiating light on the imprint material (curing step). Subsequently, in step S414, the imprint head 6 raises the mold chuck 9 in the Z direction to separate the mold 1 from the cured imprint material on the substrate (demolding step).

[0073] Although the normal sequence of the imprint process is described above with reference to Figure 4 For the purpose of device calibration, a similar sequence can be performed even when there is no imprint material on the substrate. Further, the pressure control (control to deform the mold 1 convex with respect to the substrate side), height (Z-direction position) control, tilt control, and force control are stored in advance as control curves in the storage unit 19 and are executed by the control unit 18.

[0074] In the imprint process, in order to further improve the productivity (throughput), it is necessary to shorten the time required for the dynamic diffusion steps. Figure 5 5a, 5b, and 5c of Figure 55a, 5b, and 5c respectively show the experimental results obtained when the time required for the dynamic diffusion step is set to 0.6 seconds, 0.5 seconds, and 0.4 seconds. However, note that the time until the end of the filling step (the sum of the time required for the dynamic diffusion step and the time required for the filling step) is 0.8 seconds, which is the same condition throughout the experiment. In this case, referring to Figure 5 5a, 5b, and 5c, as the time required for the dynamic diffusion step is shortened, unfilled defects tend to occur, resulting in an increase in the number of unfilled defects. Therefore, if the time required for the dynamic diffusion step is shortened unnecessarily, the unfilled defects increase, leading to a decrease in productivity.

[0075] Consider the experimental results obtained by changing the time required for the dynamic diffusion step. Figure 6 6a, 6b, and 6c respectively show the contact state between the imprint material on the substrate and the mold 1 (the table area 2) and the image 40 obtained by the observation unit 14 according to the contact state, and show different contact states respectively. Figure 6 6a, 6b, and 6c respectively show the curved surfaces 50, 60, and 70, which show different contact states and the shape (deformation amount) of the mold 1.

[0076] Figure 6 6a shows a state where the imprint material on the substrate is not in contact with the mold 1. In this state, the image 40 obtained by the observation unit 14 does not include an interference pattern.

[0077] Figure 6 6b shows a state where the imprint material on the substrate is in contact with the mold 1 at a contact radius (distance) defined by the contact boundary 43, and in this state, the image 40 obtained by the observation unit 14 includes an interference pattern IF43. The interference pattern IF43 indicates that since the interval between the interference fringes near the contact boundary 43 is small, the inclination (curvature of the curved surface 60) of the convex shape of the mold 1 near the contact boundary 43 is large.

[0078] Figure 6 6c shows a state where the imprint material on the substrate is in contact with the mold 1 at a contact radius (distance) defined by the contact boundary 44, and in this state, the image 40 obtained by the observation unit 14 includes an interference pattern IF44. More specifically, Figure 6 6c shows a state where, when the pressure applied to the core removal portion 8 of the mold 1 is maintained constant, the mold 1 is pushed into the imprint material on the substrate so that the contact boundary 43 becomes the contact boundary 44. The interference pattern IF44 indicates that since the interval between the interference fringes near the contact boundary 44 is large, compared with Figure 6The inclination (curvature of the curved surface 60) of the convex shape of the mold 1 shown in 6b is further reduced compared to the inclination (curvature of the curved surface 70) of the convex shape of the mold 1.

[0079] Reference will be made to Figure 7 and Figure 8 for a detailed description of Figure 6 the respective states shown in 6a, 6b, and 6c of Figure 7 . The curve C50 indicates the shape (curved surface 50) of the mold 1 in the state where the imprinting material on the substrate is not in contact with the mold 1 ( Figure 6 6a of ). The curve C60 indicates the shape (curved surface 60) of the mold 1 in the state where the imprinting material on the substrate is in contact with the mold 1 with a contact radius defined by the contact boundary 43 ([[]] Figure 6 6b of ). Similarly, the curve C70 indicates the shape (curved surface 70) of the mold 1 in the state where the imprinting material on the substrate is in contact with the mold 1 with a contact radius defined by the contact boundary 44 ([[]] Figure 6 6c of ).

[0080] Regarding Figure 6 the interference patterns shown in 6a, 6b, and 6c of Figure 7 , the observation shows that as the contact area between the imprinting material on the substrate and the mold 1 increases, the interval between the interference fringes near the contact boundary also increases. Referring to Figure 8 , when the height of the half pitch of the interference fringes is indicated by the dashed line 80, the increase in the interval between the interference fringes means an increase in the contact boundary. In other words, as shown in

[0081] Figure 8 , as the interval between the interference fringes increases, the inclination (curvature of the curved surfaces 50, 60, and 70) of the convex shape of the mold 1 decreases.

[0082] Figure 5 Returning to the above experimental results, from Figure 5As can be understood from the unfilled defect distribution shown in 5c, regardless of the time required for the dynamic diffusion step, the relative inclination between the mold 1 and the substrate 4 at the contact boundary is reduced particularly in the peripheral portion of the table region 2 (projection region). However, it should be noted that this tendency increases as the time required for the dynamic diffusion step is shortened. The main factor may be that increasing the diffusion rate of the imprint material on the substrate increases the pressure of the gas present between the mold 1 and the substrate 4, and increases the number of molecules of the gas trapped between the mold 1 and the substrate 4 (the imprint material on the substrate).

[0083] To solve such a problem, a material with high air permeability can be stacked on the mold 1 or the substrate 4. However, this not only increases the number of steps due to the step of stacking the material with high air permeability, but also increases the cost of the mold 1 or the substrate 4.

[0084] In the imprinting apparatus IMP, increasing the inclination (curvature of the curved surface) of the convex shape of the mold 1 at the contact boundary can suppress the increase in the number of molecules of the trapped gas caused by increasing the diffusion rate of the imprint material on the substrate. For example, as disclosed in Patent Document 4, by changing the thickness, size (magnitude), shape, etc. of the core removal portion 8 of the mold 1, the amount of deformation of the mold 1 can be changed, that is, the inclination of the convex shape of the mold 1 at the contact boundary. However, changing the thickness, size, shape, etc. of the core removal portion 8 of the mold 1 is accompanied by the risk of the mold 1 falling or breaking, so the design values need to be reexamined. This reexamination of the design values requires a lot of time and resources, thus hindering the improvement of the productivity (throughput) of the imprinting apparatus IMP.

[0085] Therefore, in the present embodiment, in order to increase the inclination of the convex shape of the mold 1 at the contact boundary, the pressure applied to the core removal portion 8 (the second surface 1b) of the mold 1 is increased to increase the amount of deformation of the mold 1 (the table region 2). However, increasing the amount of deformation of the mold 1 will increase the risk of the mold 1 falling from the mold chuck 9 and breaking the mold 1. Therefore, the present inventor makes the pressure adjustment unit 7 apply a specific pressure to the core removal portion 8 of the mold 1, and calculates the magnitude of the force applied to the mold 1 that causes the mold 1 to fall from the mold chuck 9. Table 1 indicates the apparatus conditions in this calculation.

[0086] [Table 1]

[0087] Mold Dimensions 150mm × 150mm Core - removed Diameter 64mm Mold Thickness 6.35mm Core - removed Thickness 1.1mm Table Area Dimensions 33mm × 33mm Suction Area of Mold Chuck <![CDATA[2645mm 2 > Core - removed Area <![CDATA[3632mm 2 > Allowable Value of Mold Chuck Adsorption Pressure -50kpa

[0088] Figure 9 Shows the calculation results under the apparatus conditions shown in Table 1. Refer to Figure 9, MVac represents the suction force (holding force) of the mold chuck 9 on the mold 1, BPF represents the force that causes the mold 1 to drop (dropping force), and TotalVac represents the force obtained by combining the suction force MVac and the dropping force BPF (combined force). In this case, the plus sign indicates the direction in which the mold 1 drops from the mold chuck 9.

[0089] Refer to Figure 9 , as the pressure applied to the core removal portion 8 of the mold 1 increases, the dropping force (BPF) that causes the mold 1 to drop increases proportionally. The suction force (MVac) of the mold chuck 9 on the mold 1 is not affected by the pressure applied to the core removal portion 8 of the mold 1 and is constant. Therefore, when the combined force (TotalVac) obtained by combining the suction force (MVac) and the dropping force (BPF) increases proportionally to the pressure applied to the core removal portion 8 of the mold 1 and exceeds 0, the mold 1 drops from the mold chuck 9. Therefore, from a design perspective, it is difficult to simply increase the pressure applied to the core removal portion 8 of the mold 1.

[0090] The present inventor calculated the relationship between the thickness of the core removal portion 8 of the mold 1 and the maximum stress applied to the outer peripheral portion (edge portion) of the core removal portion 8 when pressure is applied to the core removal portion 8 of the mold 1. Figure 10 The results obtained by calculating the relationship between the thickness of the core removal portion 8 of the mold 1 and the maximum stress applied to the outer peripheral portion of the core removal portion 8 are shown. Refer to Figure 10 , the curve PA represents the relationship when the pressure applied to the core removal portion 8 of the mold 1 is set to the reference pressure value. The curve PB represents the relationship when the pressure applied to the core removal portion 8 of the mold 1 is set to a pressure value less than the reference pressure value, and the curve PC represents the relationship when the pressure applied to the core removal portion 8 of the mold 1 is set to a pressure value greater than the reference pressure value.

[0091] Refer to Figure 10 , it can be seen that when the thickness of the core removal portion 8 of the mold 1 is less than the current value of 1.1 mm, the maximum stress (σmax) applied to the outer peripheral portion (edge portion) of the core removal portion 8 increases. In addition, as the pressure applied to the core removal portion 8 of the mold 1 increases, the curve (curve PC) rises, that is, the maximum stress increases. As the maximum stress applied to the outer peripheral portion of the core removal portion 8 of the mold 1 increases, the risk of the mold 1 breaking increases. Therefore, from a safety perspective, it is not easy to simply change the thickness of the core removal portion 8 of the mold 1 and the pressure applied to the core removal portion 8 of the mold 1.

[0092] As described above, in order to change the pressure applied to the core removal portion 8 of the mold 1, safety must be ensured. The following will describe the specific techniques for improving the filling performance of the imprint material in the mold 1 while ensuring safety.

[0093] Figure 11This is a diagram schematically showing the state where the mold 1 is in contact with the substrate 4 (the imprinting material on the substrate). First, by setting 2R as the diameter of the core-removing portion 8 of the mold 1 and P as the pressure value of the pressure applied to the core-removing portion 8, the state on the mold side is calculated. More specifically, the state where there is no reaction force from the substrate 4 is calculated. In this case, the maximum stress σmax applied to the outer peripheral portion of the core-removing portion 8 of the mold 1 and the maximum deformation amount (bending amount) Wmax of the mold 1 can be obtained from the following formula (1).

[0094] [Mathematical formula 1]

[0095]

[0096]

[0097]

[0098] In formula (1), t represents the thickness of the core-removing portion 8 of the mold 1, v represents the Poisson's ratio of the mold 1, and E represents the longitudinal elastic modulus of the mold 1.

[0099] In addition, by setting a as the diameter of the contact area between the mold 1 and the substrate 4, the maximum stress σmax and the maximum deformation amount Wmax regarding the state where the mold 1 is held on the substrate 4 with a force F can be obtained from formula (2):

[0100] [Mathematical formula 2]

[0101]

[0102]

[0103] The combined representation of formulas (1) and (2) shows the final state where the mold 1 is in contact with the substrate 4. Figure 12 and Figure 13 Shows the results obtained by calculating values while changing the pressure value P of the pressure applied to the core-removing portion 8 of the mold 1 and the force F when the mold 1 is in contact with the substrate 4, and comparing the calculated values with the design values. Note that the calculation is performed using standard values of other conditions such as the thickness t of the core-removing portion 8, the diameter 2R of the core-removing portion 8, the diameter a of the contact area, and the coefficients of the material of the mold 1.

[0104] Figure 12 Shows the relationship between the pressure applied to the core-removing portion 8 of the mold 1 and the combined force (TotalVac) obtained by combining the suction force of the mold chuck 9 on the mold 1 and the force causing the mold 1 to drop, as well as the dropping area 100 where the mold 1 may drop from the mold chuck 9. Refer to Figure 12, it can be said that under the condition that the suction force of the mold chuck 9 clamping the mold 1 is not less than -50 N, the mold 1 will not fall off the mold chuck 9, thus ensuring safety.

[0105] Figure 13 Shows the relationship between the pressure applied to the core-removing portion 8 of the mold 1 and the maximum stress (σmax) applied to the outer peripheral portion of the core-removing portion 8, and the cracking region 101 where the mold 1 may crack. Figure 13 Indicates that under the condition that the maximum stress does not exceed 18 N / mm as the design value 2 , the mold 1 will not crack, thus ensuring safety.

[0106] Consider the control line shape for meeting the conditions for ensuring safety (conditions set by combining the pressure value P of the pressure applied to the core-removing portion 8 of the mold 1 and the force F when the mold 1 contacts the substrate 4) and improving the filling performance of the imprinting material in the mold 1. In the state where the mold 1 is in contact with the substrate 4 (the imprinting material on the substrate), that is, during their contact, the inclination (hereinafter referred to as "curvature") of the convex shape of the mold 1 is smaller than the curvature of the mold 1 in the state where the mold 1 is not in contact with the substrate 4. Therefore, the filling performance of the imprinting material at this portion can be improved by gradually increasing the curvature of the mold 1 before the portion where the curvature of the mold 1 is the smallest. The portion where the curvature of the mold 1 is the smallest is the outer peripheral portion of the table area 2 of the mold 1, especially the portion near the corner, so it is preferable to adjust the control line shape to the corner of the table area 2 within the range of the conditions for ensuring safety.

[0107] First, the basic control line shape will be described with reference to Figure 14 The pressure control line shape 102 is a line shape indicating the pressure value of the pressure applied to the core-removing portion 8 of the mold 1. This line shape covers from the dynamic contact step to the static filling step. In the pressure control line shape 102, usually a pressure value is set as the initial value to prevent the mold 1 from falling off the mold chuck 9 and prevent the mold 1 from cracking. In the pressure control line shape 102, a pressure value that rapidly decreases to 0 after a predetermined period is set. The force control line shape 103 is a line shape of a curve indicating the value of the pressing force with which the imprinting head 6 presses the mold 1 against the imprinting material on the substrate. This line shape covers from the dynamic contact step to the static filling step. In the force control line shape 103, the value of the pressing force is set as the initial value, which increases the force from the initial state where the mold 1 contacts the imprinting material on the substrate and increases the contact area between the mold 1 and the imprinting material on the substrate. In the force control line shape 103, a pressing force value that rapidly decreases to 0 after a predetermined period is set.

[0108] Next, it will be described with reference to Figure 15Describe the control line shape according to this embodiment. The pressure control line shape 104 is a line shape indicating the pressure value of the pressure applied to the core removal portion 8 of the mold 1. This line shape covers from the dynamic contact step to the static filling step. In the pressure control line shape 104, a pressure value similar to the pressure control line shape 102 is set as the initial value. In the pressure control line shape 104, a pressure value is set such that after the mold 1 contacts the imprint material on the substrate and when the pressing head 6 applies a pressing force to the imprint material on the substrate, this pressure value increases from the initial value. However, note that as described above, the pressure value set in the pressure control line shape 104 (i.e., the pressure value increased from the initial value) is set within the range of conditions that ensure safety. More specifically, the pressure control line shape 104 (the pressure value of the pressure to be applied to the core removal portion 8 of the mold 1) is set to satisfy the relationship represented by the following inequality (3):

[0109] {BP(t) - BP(0)} × a + {IHF(t) - IHF(0)} ≤ 0 - ···(3)

[0110] In inequality (3), BP(0) represents the initial value of the pressure applied to the core removal portion 8 of the mold 1, BP(t) represents the pressure value at t seconds after the mold 1 contacts the imprint material on the substrate, a represents the force-pressure conversion coefficient [N / kPa] of the pressure applied to the core removal portion 8 of the mold 1, IHF(0) represents the initial value of the pressing force of the pressing head 6, and IHF(t) represents the pressing force at t seconds after the mold 1 contacts the imprint material on the substrate. Assume that the direction of increasing the pressure applied to the core removal portion 8 of the mold 1 is defined as the positive direction of the force, and the direction of applying the pressing force is defined as the negative direction of the force.

[0111] Inequality (3) indicates that as long as inequality (3) is satisfied after the mold 1 contacts the imprint material on the substrate after the start of the contact step, a pressure control line shape can be formed that starts to increase the pressure applied to the core removal portion 8 of the mold 1.

[0112] In addition, the force control line shape 105 is a line shape indicating the value of the pressing force used by the pressing head 6 to press the mold 1 against the imprint material on the substrate. This line shape covers from the dynamic contact step to the static filling step. In the force control line shape 105, a value of the pressing force is set as the initial value, and this value increases the force from the initial state when the mold 1 contacts the imprint material on the substrate to increase the contact area between the mold 1 and the imprint material on the substrate. In addition, in the force control line shape 105, a value of the pressing force that rapidly decreases to 0 from the initial value after a predetermined period is set. Refer to Figure 15 , at each moment after the mold 1 contacts the imprint material on the substrate, the pressure (force) applied to the core removal portion 8 of the mold 1 is less than the pressing force of the pressing head 6.

[0113] In the force control line shape 105, a pressing force value larger than the value set in the force control line shape 103 is set. This is because the force control line shape 105 needs to be synchronized (interlocked) with the pressure control line shape 104, and the pressing force of the stamper 6 needs to increase synchronously with the increase in the pressure applied to the core removal portion 8 of the mold 1.

[0114] Figure 16 The relationship between the pressure applied to the core removal portion 8 of the mold 1 and the maximum deformation amount (Wmax) of the mold 1 is shown. Referring to Figure 16 , it can be seen that, for example, when the pressure of the stamper 6 is 40 N, even when the pressure applied to the core removal portion 8 of the mold 1 changes from the pressure value BPA to the pressure value BPC, a pressing force of nearly 60 N is required to deform the mold 1 by the same deformation amount. Therefore, it is necessary to form the force control line shape 105 so that the force control line shape 105 is synchronized with the pressure control line shape 104 and the speed at which the stamper 6 spreads the imprinting material on the substrate is kept constant.

[0115] As described above, in the present embodiment, the control unit 18 controls the pressure applied to the core removal portion 8 of the mold 1 by the pressure adjustment unit 7 during the imprinting process, more specifically, during the dynamic diffusion step. More specifically, the force (pressure) applied to the core removal portion 8 by the pressure adjustment unit 7 after the contact between the table surface area 2 of the mold 1 and the imprinting material is set to be greater than the force applied to the core removal portion 8 by the pressure adjustment unit 7 before the contact between the table surface area 2 and the imprinting material. For example, before the contact between the mold 1 and the imprinting material, the pressure on the core removal portion 8 that should be adjusted by the pressure adjustment unit 7 is set to a first pressure value (initial value) to form a convex table surface area 2 with respect to the substrate side. While bringing the mold 1 into contact with the imprinting material and pressing against the imprinting material, the pressure on the core removal portion 8 that should be adjusted by the pressure adjustment unit 7 is set to a second pressure value greater than the first pressure value. This makes it possible to achieve the pressure control as shown in the pressure control line shape 104 in Figure 15 . Although the present embodiment has illustrated the case where the pressure on the core removal portion 8 that should be adjusted by the pressure adjustment unit 7 is changed from the first pressure value to a second pressure value greater than the first pressure value within a predetermined time after the contact between the mold 1 and the imprinting material, the present invention is not limited thereto. For example, at the timing of the contact between the mold 1 and the imprinting material, the pressure on the core removal portion 8 that should be adjusted by the pressure adjustment unit 7 can be changed from the first pressure value to a second pressure value greater than the first pressure value.

[0116] As described above, in the dynamic diffusion step, the imprint head 6 and the pressure adjustment unit 7 are controlled such that the pressing force with which the imprint head 6 presses the mold 1 against the imprint material is synchronized with the pressure (force) applied to the core removal portion 8 of the mold 1 by the pressure adjustment unit 7. Further, the imprint head 6 is controlled based on information such as the increase in the contact area obtained by the observation unit 14, for example, so as to keep the diffusion rate of the imprint material constant (so as to increase the contact area between the mold 1 and the imprint material at a constant rate). This control is particularly effective when such control is performed during the period of increasing the pressing force among the periods included in the dynamic diffusion step of increasing and decreasing the pressing force.

[0117] The results obtained by simulation using the control line shape according to the present embodiment will be described below. In the simulation, a simulator developed by the present applicant (Nilus: Nanoimprint Lithography Unified Simulator) is used. Such a simulator can calculate the deformation of the mold 1 based on the pressure of the gas (gas pressure) existing between the mold 1 and the substrate 4 by calculating the pressure of the gas according to the control line shape. This makes it possible to evaluate the curvature of the mold 1 at the contact boundary between the mold 1 and the imprint material on the substrate. Further, the filling speed (filling rate) of the imprint material can be evaluated by calculating the number of molecules of the gas confined between the mold 1 and the imprint material on the substrate.

[0118] First, the curvature of the corner portion of the tabletop area 2 of the mold 1 is evaluated as the curvature of the mold 1 at the contact boundary. The evaluation conditions include the size of the mold 1: 150 mm × 150 mm, the size of the tabletop area 2: 26 mm × 33 mm, the height of the tabletop area 2: 30 μm, and the pattern formed in the tabletop area 2: columnar patterns having different sizes of several tens of nanometers. The droplet pattern of the imprint material on the substrate is a standard repeating grid pattern arranged in a staggered manner.

[0119] will be referred to Figure 17 The method of evaluating the curvature of the mold 1 will be described. As Figure 17 shown, the curvature of the mold 1 is evaluated by drawing a cross-section of the outer shape 106 that defines the tabletop area 2 of the mold 1, and this cross-section is taken along the arrow 107 pointing from the lower left corner of the tabletop area 2 to the center of the tabletop area 2.

[0120] Figure 18 shows the result obtained by evaluating the curvature of the mold 1 by using Figure 14 the basic control line shape shown. Referring to Figure 18 , the plot 108 and the plot 109 indicate the results obtained by evaluating the curvature of the mold 1 by using two different types of control line shapes as the basic control line shape. Figure 19 shows the result obtained by evaluating the curvature of the mold 1 by using Figure 15 the control line shape according to the present embodiment shown. Referring toFigure 19 The drawing lines 110 and 111 indicate the results obtained by evaluating the curvature of the mold 1 by using two different types of control line shapes as the control line shapes according to the present embodiment. When evaluating the above four different control line shapes, the drawing lines 108 to 111 indicate the curvature of the mold 1 simultaneously (more specifically, 0.2 seconds, which is the set value of the time required for the dynamic diffusion step).

[0121] The drawing lines 108 and 109 corresponding to Figure 14 the basic control line shape shown are compared with each other. The curvature of the mold 1 at the contact boundary indicated by the drawing line 108 is greater than the curvature of the mold 1 at the contact boundary indicated by the drawing line 109. Referring to the drawing line 108, the distance of the contact boundary from the corner (0 mm) of the table area 2 is large, and the corner of the table area 2 does not press against the imprint material on the substrate within the time required for the dynamic diffusion step. In contrast, referring to the drawing line 109, although it seems that the distance of the contact boundary from the corner of the table area 2 is small, this distance is not much different from the distance indicated by the drawing line 108, and the curvature of the mold 1 seems to continue in a very small state near the corner of the table area 2. Therefore, referring to the drawing line 109 similar to the drawing line 108, the corner of the table area 2 does not sufficiently press against the imprint material on the substrate.

[0122] As described above, Figure 14 the basic control line shape shown in indicates that the dynamic diffusion step (pressing the mold 1 against the imprint material on the substrate) cannot be completed within 0.2 seconds. In addition, even if the diffusion speed of the imprint material on the substrate is increased, since the curvature of the mold 1 is significantly reduced, the gas also tends to be restricted between the mold 1 and the imprint material on the substrate. This makes it difficult to improve the filling performance of the imprint material. The restriction of the gas will be supplementarily described with reference to specific examples later.

[0123] Referring to the drawing lines 110 and 111 corresponding to Figure 15 the control line shape according to the present embodiment shown, compared with the drawing lines 108 and 109, the distance of the contact boundary from the corner of the table area 2 is small. In addition, the drawing lines 110 and 111 indicate that the curvature of the mold 1 is maintained very high, and the corner of the table area 2 sufficiently presses against the imprint material on the substrate.

[0124] As described above, the control line shape according to the present embodiment enables a high curvature to be maintained near the corner of the table area 2 even if the time required for the dynamic diffusion step is shortened.

[0125] The difference in the curvature of the mold 1 at the contact boundary will be described in detail below. Three pressure values are applied to the core removal portion 8 of the mold 1 for the imprint process. While keeping the distance of the contact boundary from the center of the table area 2 almost the same, the curvature of the mold 1 is calculated and evaluated according to the simulation. AsFigure 20 As shown, the time required for the contact step is set to 0.5 seconds, and a pressure control line shape PCPA with a pressure value of 28 kPa, a pressure control line shape PCPB with a pressure value of 34 kPa, and a pressure control line shape PCPC with a pressure value of 40 kPa are created. Figure 21 Illustrated is Figure 20 the simulation results of the three pressure control line shapes PCPA, PCPB, and PCPC shown. Referring to Figure 21 , it can be seen that as long as the pressure applied to the core removal portion 8 of the mold 1 is equal to or greater than 28 kPa, the curvature of the mold 1 remains almost the same.

[0126] As Figure 22 shown, the time required for the contact step is set to 0.2 seconds, and a pressure control line shape PCPA' with a pressure value of 28 kPa, a pressure control line shape PCPB' with a pressure value of 34 kPa, and a pressure control line shape PCPC' with a pressure value of 40 kPa are created. Imprinting is performed using the pressure control line shapes PCPA', PCPB', and PCPC'. While the distance of the contact boundary from the center of the table area 2 remains almost the same, the curvature of the mold 1 is calculated and evaluated based on the simulation. Figure 23 Illustrated is Figure 22 the simulation results of the three pressure control line shapes PCPA', PCPB', and PCPC' shown. Referring to Figure 23 , it can be seen that the results are very different from those shown in Figure 21 , and as the pressure applied to the core removal portion 8 of the mold 1 increases, the curvature of the mold 1 increases and approaches the simulation results for the pressure control line shape PCPA.

[0127] Comparing the Figure 23 curves indicating the curvature of the mold 1 shown. The pressure control line shape PCPA indicates that the height of the table area 2 is approximately 35 nm near 10 mm from the corner of the table area 2. This height corresponds to the height of the imprint material on the substrate, which is determined by the amount and number of drops of the imprint material. The height of the table area 2 increases sharply as the distance to the corner of the table area 2 decreases to, for example, approximately 6 mm. On the contrary, as the distance approaches 10 mm, the height of the table area 2 gradually increases. When this distance exceeds 6 mm, the height of the table area 2 does not change significantly and gradually decreases. This trend increases in the order of the pressure control line shapes PCPC', PCPB', and PCPA'. Therefore, qualitatively, increasing the pressure applied to the core removal portion 8 of the mold 1 and the pressing force of the imprint head 6 can make the curvature of the mold 1 when the contact step requires 0.2 seconds approach the curvature of the mold 1 when the contact step requires 0.5 seconds. However, in practice, the upper limit should be determined by the control specifications in the imprinting device IMP.

[0128] Generally, it is considered that shortening the time required for the contact step will cause the curvature of the mold 1 at the contact boundary to greatly affect the gas pressure between the mold 1 and the imprint material on the substrate. This seems to make it difficult to maintain the high curvature of the mold 1. However, according to the control line shape of the present embodiment, even if the time required for the contact step is shortened, the high curvature of the mold 1 can be maintained in the same manner as before the time required for the contact step is shortened.

[0129] Subsequently, the difference in the number of gas molecules trapped between the mold 1 and the imprint material on the substrate is evaluated based on the difference in the curvature of the mold 1 during the imprint process. Figure 24 24a and 24b show distribution diagrams indicating the number of gas molecules trapped between the mold 1 and the imprint material on the substrate. In Figure 24 24a and 24b, the black areas indicate the state where the number of gas molecules is large, while the white areas indicate the state where the number of gas molecules is small. Figure 24 24a shows the distribution diagram 112 corresponding to the Figure 18 drawn line 108 shown. Figure 24 24b shows the distribution diagram 113 corresponding to the Figure 18 drawn line 109 shown.

[0130] Referring to Figure 24 24a and 24b, the distribution diagrams 112 and 113 have similar distributions in terms of the number of gas molecules, and it can be seen that the number of gas molecules is large near the corners of the mesa region 2. The black area in the distribution diagram 113 is wider than the black area in the distribution diagram 112. Therefore, as described above, since the black area is wide, this trend seems to be affected by the drawn line 109 with a smaller curvature of the mold 1. Similarly, in the case of the drawn line 108 where the curvature of the mold 1 is not so small, since a part of the corner of the mesa region 2 does not press against the imprint material on the substrate, a large amount of gas seems to be trapped and the number of gas molecules increases.

[0131] Figure 25 25a and 25b show diagrams indicating the number of gas molecules trapped between the mold 1 and the imprint material on the substrate. Referring to Figure 25 25a and 25b, the black areas indicate a large number of gas molecules, while the white areas indicate a small number of gas molecules. Figure 25 25a shows the distribution diagram 114 corresponding to the Figure 19 drawn line 110 shown. Figure 25 25b shows the distribution diagram 115 corresponding to the Figure 19 drawn line 111 shown.

[0132] Referring to Figure 2525a and 25b are different from distribution maps 112 and 113. Distribution maps 114 and 115 indicate that the black regions near the corners of the mesa region 2 disappear, and the number of molecules of the trapped gas decreases. However, distribution maps 114 and 115 include strip regions inscribed in the mesa region 2. This phenomenon can be improved by observing the behavior of the contact distance over time and the behavior of the height of the mold 1 over time, and making the diffusion rate of the imprint material on the substrate constant with respect to the resistance of the gas pressure. This enables the gas trapped between the mold 1 and the imprint material on the substrate to be kept constant and minimizes the number of molecules of the trapped gas. In other words, it is preferable to create control line shapes (pressure control line shape and force control line shape) that make the diffusion rate of the imprint material on the substrate constant. These control line shapes can be more effectively improved by creating them as continuous control line shapes not only in the contact step but also in the subsequent step where the pressure in the core removal portion 8 is reduced. More specifically, the behavior of the contact distance over time and the behavior of the height of the mold 1 over time can be obtained based on the simulation results or experiments (results of the imprint process) using the imprint apparatus IMP.

[0133] As described above, this embodiment can provide the imprint apparatus IMP, which can reduce the molecular weight of the gas trapped between the mold 1 and the imprint material on the substrate by maintaining a high curvature of the mold 1, and is conducive to improving productivity.

[0134] The pattern of the cured product formed using the imprint apparatus IMP is permanently used for at least some of various articles, or temporarily used when manufacturing various articles. The articles are circuit elements, optical elements, MEMS, recording elements, sensors, molds, etc. Examples of circuit elements are volatile and 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 molds are molds for imprinting.

[0135] The pattern of the cured product is directly used as a constituent member of at least some of the above articles or temporarily used as a resist mask. After etching or ion implantation in the substrate processing step, the resist mask is removed.

[0136] Next, a detailed method for manufacturing an article is described. As Figure 26 shown in 26a, a substrate such as a silicon wafer having a processing material such as an insulator formed on its surface is prepared. Next, the imprint material is applied to the surface of the material to be processed by an inkjet method or the like. The state where the imprint material is applied to the substrate as a plurality of droplets is shown here.

[0137] As Figure 26As shown in 26b, the surface of the mold used for imprinting, which has a pattern of protrusions and grooves, faces the imprinting material on the substrate. As Figure 26 As shown in 26c, the substrate on which the imprinting material is applied is brought into contact with the mold, and pressure is applied. The gap between the mold and the material to be processed is filled with the imprinting material. In this state, when the imprinting material is irradiated with light used as curing energy through the mold, the imprinting material is cured.

[0138] As Figure 26 As shown in 26d, after the imprinting material is cured, the mold is removed from the substrate. Thus, a pattern of the cured product of the imprinting material is formed on the substrate. In the pattern of the cured product, the grooves of the mold correspond to the protrusions of the cured product, and the protrusions of the mold correspond to the grooves of the cured product. That is, the pattern of protrusions and grooves of the mold is transferred to the imprinting material.

[0139] As Figure 26 As shown in 26e, when etching is performed using the pattern of the cured product as an etching mask, the surface portion of the material to be processed where there is no cured product or where the cured product remains thin is removed to form grooves. As Figure 26 As shown in 26f, when the pattern of the cured product is removed, an article having grooves formed in the surface of the material to be processed can be obtained. Here, the pattern of the cured material is removed. However, for example, this pattern can be used as an insulating film between layers included in a semiconductor element or the like without being removed after processing, in other words, as a constituent member of the article.

[0140] Note that in this embodiment, a mold for transferring a circuit pattern having a concavo-convex pattern has been illustrated as mold 1. However, mold 1 can be a planar template including a planar portion without a concavo-convex pattern. The planar template (member) is used in a planarizing device (forming device) that performs a planarizing process (forming process) for forming a composition on a substrate into a flat shape using the planar portion. The planarizing process includes the following process: in a state where the planar portion of the planar template is in contact with a curable composition supplied onto the substrate, the curable composition is cured by light irradiation or heating. In this way, this embodiment can be applied to a forming device that forms a composition on a substrate using a planar template.

[0141] The underlying pattern on the substrate has a concave / convex profile derived from the pattern formed in the previous step. More specifically, along with the multi-layer structure of the most recent storage element, the substrate (processed wafer) may have a step of approximately 100 nm. The step caused by the gentle undulation of the entire surface of the substrate can be corrected by the focus tracking function of the exposure device (scanner) used in the lithography process. However, the fine concave / convex portions with a small pitch and falling within the exposure slit area of the exposure device directly consume the DOF (depth of focus) of the exposure device. Techniques for forming a planarization layer such as SOC (spin-on carbon) or CMP (chemical mechanical polishing) are used as conventional methods for planarizing the underlying pattern of the substrate. However, in the conventional technology, as Figure 27 shown in 27a, only a concavo-convex suppression rate of 40% to 70% can be obtained at the boundary portion between the isolated pattern region A and the repeated dense (dense line and space pattern) pattern region B, and thus sufficient planarization performance cannot be obtained. In addition, the concave / convex difference of the underlying pattern formed by multiple layers tends to increase.

[0142] As a solution to this problem, U.S. Patent No. 9,415,418 proposes the following technique: applying a resist used as a planarization layer by an inkjet dispenser and forming a continuous film using planar template imprinting. In addition, U.S. Patent No. 8,394,282 proposes the following technique: reflecting the topographical measurement results on the substrate side in the density information of each position where the resist is indicated to be coated by the inkjet dispenser. The imprint device IMP is particularly suitable as a planarization (planarizing) device that locally planarizes the substrate surface by pressing a planar template instead of the mold 102 against the pre-applied uncured resist (uncured material).

[0143] Figure 27 27a shows the substrate before planarization. The area of the convex pattern portion is small in the isolated pattern region A. In the repeated dense pattern region B, the area occupied by the convex pattern portion and the area occupied by the concave pattern portion are 1:1. The average height of the isolated pattern region A and the repeated dense pattern region B has different values according to the ratio of the convex pattern portion.

[0144] Figure 27 27b shows the state where the resist for forming the planarization layer is applied to the substrate. Figure 27 27b shows the state where the resist is applied by an inkjet dispenser based on the technique proposed in U.S. Patent No. 9,415,418. However, a spin coater can be used to apply the resist. In other words, the imprint device IMP can be applied as long as it includes a step of planarizing by pressing a planar template against the pre-applied uncured resist.

[0145] As shown Figure 27 in 27c, the planar template is made of glass or quartz that transmits ultraviolet light, and the resist is cured by irradiating it with ultraviolet light from a light source. For the gentle unevenness of the entire substrate, the planar template conforms to the contour of the substrate surface. After the resist is cured, as shown Figure 27 in 27d, the planar template is removed from the resist.

[0146] The present invention is not limited to the above embodiments, and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, the appended claims are presented to inform the public of the scope of the present invention.

[0147] This application claims priority based on Japanese Patent Application No. 2020-150738 filed on September 8, 2020, the entire content of which is incorporated herein by reference.

Claims

1. A forming device that forms a composition on a substrate by using a mold, characterized in that The forming device includes: a control unit configured to control a process of forming a film of the composition between the first surface and the substrate by bringing the first surface of the mold into contact with the composition; and a deformation unit configured to deform the first surface into a convex shape with respect to the substrate side by applying pressure to a second surface of the mold on the opposite side of the first surface, wherein the control unit controls the deformation unit during the process such that a positive pressure applied to the second surface by the deformation unit after contact between the first surface and the composition is greater than a positive pressure applied to the second surface by the deformation unit before contact between the first surface and the composition.

2. The molding device according to claim 1, wherein, The deformation unit deforms the first surface into a convex shape with respect to the substrate side by applying a force to the second surface when adjusting the pressure in a concave portion provided in the second surface.

3. A molding device that molds a composition on a substrate by using a mold, characterized in that, The forming device includes: a control unit configured to control a process of forming a film of the composition between the first surface and the substrate by bringing the first surface of the mold into contact with the composition; and a deformation unit configured to deform the first surface into a convex shape with respect to the substrate side by applying a force to a second surface of the mold on the opposite side of the first surface, wherein the deformation unit deforms the first surface into a convex shape with respect to the substrate side by applying a force to the second surface when adjusting the pressure in a concave portion provided in the second surface, and before contact between the first surface and the composition, the control unit sets the pressure in the concave portion to be adjusted by the deformation unit to a first pressure value so that the first surface is formed into a convex shape with respect to the substrate side, and while the first surface is pressed against the composition, the control unit sets the pressure in the concave portion to be adjusted by the deformation unit to a second pressure value greater than the first pressure value.

4. The molding device according to claim 3, characterized in that The control unit sets the pressure in the concave portion to be adjusted by the deformation unit to change the first pressure value to the second pressure value within a predetermined time after contact between the first surface and the composition.

5. The molding device according to claim 3, characterized in that, The control unit sets the pressure in the concave portion to be adjusted by the deformation unit to change the first pressure value to the second pressure value at the timing of contact between the first surface and the composition.

6. The shaping device according to claim 1, characterized in that, The forming device further includes: a pressing portion configured to bring the first surface into contact with the composition and press the first surface against the composition, wherein the control unit controls the pressing portion and the deformation unit during the process such that a pressing force with which the pressing portion presses the first surface against the composition is synchronized with the force applied to the second surface by the deformation unit.

7. The shaping device according to claim 6, characterized in that, The process includes a period of increasing the pressing force and a period of decreasing the pressing force.

8. The shaping device according to claim 7, characterized in that, The control unit controls the pressing portion such that the contact area between the first surface and the composition increases at a constant speed during the period of increasing the pressing force.

9. The molding device according to claim 8, wherein, The shaping device further includes: an obtaining unit configured to obtain information on an increase in the contact area between the first surface and the composition, wherein the control unit controls the pressing part based on the information such that the contact area is increased at a constant speed.

10. The molding device according to claim 9, characterized in that, The obtaining unit obtains the information according to the simulation result of the process or the result of the process.

11. The molding device according to claim 6, characterized in that, The control unit controls the deforming unit such that, at each moment after the first surface comes into contact with the composition, the force applied by the deforming unit to the second surface is less than the pressing force with which the pressing part presses the first surface against the composition.

12. The molding device according to claim 1, wherein The first surface includes a pattern, and the shaping device forms a pattern of the composition on the substrate by bringing the pattern of the first surface into contact with the composition.

13. The molding device according to claim 1, wherein, The first surface includes a flat portion, and the shaping device flattens the composition on the substrate by bringing the flat portion of the first surface into contact with the composition.

14. A method for manufacturing an article, characterized in that, The method for manufacturing an article includes: a forming step of forming a pattern on a substrate by using the shaping device defined in claim 12; a processing step of processing the substrate having the pattern formed in the forming step; and a manufacturing step of manufacturing an article from the processed substrate.

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