Lithography device, lithography method, and article manufacturing method

Abstract

A lithography device comprises: a pattern forming unit that forms a pattern using a pattern unit on a shot area on a substrate held and supported by a substrate holding and supporting unit; an acquisition unit that acquires a relationship between the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit, a holding and supporting force applied to at least a part of the substrate to hold and support the substrate, and an overlap error between the substrate and the pattern unit; a measurement unit that measures the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit; and a control unit that controls the holding and supporting force to reduce the overlap error between the substrate and the pattern unit based on the amount of positional misalignment measured by the measurement unit and the relationship acquired by the acquisition unit.

Description

Technology Field

[0001] The present invention relates to a lithography apparatus, a lithography method, a method for manufacturing an article, etc. Background Technology

[0002] Imprint technology, which transfers a pattern formed in a mold onto a substrate, is attracting attention as a lithography technology used in the manufacture of semiconductor devices. According to an imprint device utilizing imprint technology, an imprint material, which is a curable composition placed on a substrate, is brought into contact with a mold, and the imprint material is cured in that state. Then, the mold is separated from the cured imprint material on the substrate, thereby transferring the pattern of the mold onto the substrate.

[0003] An imprint device is required to transfer a mold pattern onto a substrate with high precision. A technology for controlling the pressure of a substrate holding support unit based on substrate shape information or overlap information to enable a mold pattern unit to overlap a transfer area on the substrate with high precision is disclosed in Japanese Patent Publication No. 2020-92178.

[0004] However, in conventional imprint devices, positional misalignment occurs when the substrate is placed on the substrate holding support unit. If positional misalignment occurs, there is a problem in that the deformation of the substrate may change and the optimal value of the overlap precision may change.

[0005] Therefore, one of the objectives of the present invention is to provide a lithography device capable of improving superposition precision. means of solving the problem

[0006] To achieve the objective, a lithography apparatus according to one embodiment of the present invention comprises at least one processor or circuit, the pattern forming unit configured to form a pattern using a pattern unit on a shot area on a substrate held and supported by a substrate holding and supporting unit; an acquisition unit configured to acquire in advance a relationship between the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit, a holding and supporting force applied to at least a part of the substrate to hold and support the substrate, and an overlap error between the substrate and the pattern unit; a measurement unit configured to measure the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit; and a control unit configured to control the holding and supporting force to reduce the overlap error between the substrate and the pattern unit based on the amount of positional misalignment measured by the measurement unit and the relationship acquired by the acquisition unit.

[0007] Further features of the present invention will become clear from the following description of embodiments with reference to the attached drawings. Brief explanation of the drawing

[0008] FIG. 1 is a drawing illustrating an imprint device according to a first embodiment of the present invention. FIG. 2 is a drawing illustrating, as an example, the layout of a shot area on a substrate (5) according to a first embodiment. FIG. 3a is a plan view of the substrate holding support unit (61) seen from the mold (3) side, FIG. 3b is an XZ cross-sectional view of the substrate holding support unit (61) holding and supporting the substrate (5), FIG. 3c is a drawing showing the deformation state when the pressure of the pressurized area (64a) is set to positive pressure, and FIG. 3d is a drawing showing the deformation state of the substrate (5) when the pressure is set to negative pressure. FIGS. 4a to 4f are drawings for explaining the relationship between the substrate position, the pressure of the pressurized area (64a), and the overlap error for the substrate holding support unit. FIG. 5 is a flowchart for explaining the imprint processing performed by an imprint device according to a first embodiment. FIG. 6 is a drawing illustrating an example of a correction table obtained in step S101 according to the first embodiment. FIG. 7 is a drawing for explaining a method for measuring substrate position misalignment according to a second embodiment of the present invention. Specific details for implementing the invention

[0009] Hereinafter, preferred modes of the present invention will be described using examples with reference to the attached drawings. In each drawing, the same reference numerals are assigned to identical members or elements, and redundant descriptions are omitted or simplified.

[0010] <First Embodiment>

[0011] First, an overview of the imprint device (1) as a lithography device according to the first embodiment will be described. The imprint device (1) is a molding device that forms a pattern of a cured product in which an uneven pattern of the mold is transferred by bringing an imprint material, which is a photocurable composition supplied to a substrate, into contact with a mold and applying curing energy to the imprint material.

[0012] FIG. 1 is a diagram illustrating the configuration of an imprint device according to a first embodiment of the present invention. The imprint device (1) according to the present embodiment uses a photocuring method to cure the imprint material by irradiating it with ultraviolet rays, but a thermal curing method to cure the imprint material by applying heat, for example, may be used. Note that in each of the following drawings, the Z-axis of the XYZ coordinate system is set in a direction parallel to the irradiation axis of the ultraviolet rays with respect to the mold, and the X-axis and Y-axis are set in directions that intersect perpendicularly in a plane perpendicular to the Z-axis.

[0013] The imprint device (1) includes an inspection unit (2), a mold stage (4) that holds and supports a mold (3), a substrate stage (6) that holds and supports a substrate (5), a pre-alignment unit (7), and an application unit (8) that supplies an imprint material. Additionally, the imprint device (1) includes an off-axis alignment measurement system (9), an alignment measurement system (10), a charging monitor (11), a control unit (14), and a console unit (15). The substrate stage (6) includes a substrate holding and supporting unit (61) that holds and supports a substrate (5) and a substrate moving unit (62) that moves the substrate holding and supporting unit (61) (substrate (5)) in the X direction and the Y direction.

[0014] The irradiation unit (2) includes a light source unit (21) that emits light to cure an imprint material on a substrate and an optical member (22) for inducing the light emitted from the light source unit (21) to the imprint material on the substrate, and the irradiation unit (2) irradiates light onto the imprint material on the substrate through a transparent mold (3).

[0015] The optical member (22) includes an optical element for adjusting light emitted from the light source unit (21) into light suitable for imprint processing.

[0016] The mold (3) has a rectangular outer shape when viewed from the Z direction and has a pattern unit (3a) having three-dimensional irregularities on the surface facing the substrate (5). The material of the mold (3) is a material capable of transmitting ultraviolet rays, such as quartz glass. Additionally, the mold (3) may include a cavity (concave part) (3b) to facilitate deformation of the pattern unit (3a).

[0017] The cavity (3b) has a circular shape when viewed from the Z direction, and the thickness of the lower part of the cavity (3b) is appropriately set according to the shape and material of the mold (3). In addition, a light-transmitting material (13) having a sealed space in a part of the opening area within the mold stage (4) described later and a space (12) surrounded by the cavity (3b) is placed in the opening area, and the pressure within the space (12) can be controlled by a pressure adjustment unit not shown.

[0018] The mold stage (4) includes a mold holding support unit (41) that holds and supports the mold (3) by vacuum suction force or electrostatic force, a mold moving unit (42) that moves the mold holding support unit (41) in the Z direction, and a mold deformation mechanism (43).

[0019] The mold holding support unit (41) and the mold moving unit (42) have an opening area in their center (inside) so that light from the irradiation unit (2) is irradiated onto the imprint material on the substrate.

[0020] The mold moving unit (42) includes an actuator, such as a voice coil motor or an air cylinder, for example.

[0021] The mold moving unit (42) causes the mold holding support unit (41) (mold (3)) to move in the Z direction in order to bring the pattern unit (3a) into contact with the imprint material on the substrate or to pull the mold (3) away from the imprint material on the substrate.

[0022] The mold moving unit (42) may be configured to have the function of adjusting the position of the mold holding support unit (41) not only in the Z direction but also in the X and Y directions. Additionally, the mold moving unit (42) may be configured to have the function of adjusting the position of the mold holding support unit (41) in the θ (rotation around the Z-axis) direction and the tilt function for adjusting the inclination of the mold holding support unit (41).

[0023] The mold deformation mechanism (43) corrects the shape of the mold (3) (pattern unit (3a)) by applying an external force or displacement to the side of the mold (3). The mold deformation mechanism (43) includes, for example, a plurality of actuators and is configured to press each side of the mold (3) at a plurality of positions. The substrate (5) is, for example, a single-crystal silicon substrate or a silicon-on-insulator (SOI) substrate.

[0024] FIG. 2 is a drawing illustrating, as an example, the layout of a shot area on a substrate (5) according to a first embodiment. Note that in the first embodiment, the shot area is an area where a pattern is formed by an imprint process performed once. Also, the target shot area is a shot area to be subjected to the next imprint process.

[0025] The imprint device (1) performs an imprint process whenever the target shot area changes. The imprint process includes, at least, the step of applying an imprint material to the target shot area, the step of bringing the pattern unit (3a) and the imprint material into contact with each other, the step of filling the pattern unit (3a) with the imprint material, and the step of curing the imprint material. Additionally, the imprint process includes the step of pulling the cured imprint material and the mold (3) away from each other.

[0026] A plurality of shot areas are arranged in a matrix shape on the substrate (5) as shown in FIG. 2. In the first embodiment, in order to maximize the effective area (total area of ​​the area where the pattern is transferred) on the substrate (5), the imprint processing is performed not only on the inner shot area (51) of the substrate (5) but also on the peripheral shot area (52) including the outer periphery of the substrate (5). The peripheral shot area is a shot area located partially outside the outer periphery of the substrate (5) and is also called a "missing shot area."

[0027] The pre-alignment unit (7) includes a pre-alignment stage not shown for mounting a substrate (5) thereon and a sensor not shown for measuring the position of the substrate (5), and detects the position of a notch or orientation flat of the substrate (5) by the sensor and measures the position of the substrate (5).

[0028] The pre-alignment stage performs a correction drive based on the measurement result, receives the substrate (5) from the outside at the corrected position by a substrate return hand (not shown), and then places the substrate (5) on the substrate holding support unit (61). Note that based on the pre-alignment result, the receiving position of the substrate return hand or the position of the substrate holding support unit (61) receiving the substrate (5) can be changed.

[0029] FIG. 3a is a plan view of the substrate holding support unit (61) seen from the mold (3) side. As shown in FIG. 3a, on the upper surface of the substrate holding support unit (61) (the surface facing the back surface of the substrate (5)), a plurality of regions (pressure regions) (64a, 64b, 64c) are formed by a plurality of partitions (63a, 63b, 63c). That is, the substrate holding support unit (61) includes a plurality of pressure regions for pressing and holding support the substrate. The plurality of pressure regions (64a, 64b, 64c) are divided coaxially, so positive pressure or negative pressure can be independently applied to each of the pressure regions (64a, 64b, 64c).

[0030] In the example of FIG. 3a, a plurality of pressure regions (64a, 64b, 64c) are formed by erecting partitions (63a, 63b, 63c) on the upper surface of the substrate holding support unit (61), but these may be grooves formed by digging into the upper surface of the substrate holding support unit (61). FIG. 3b is an XZ cross-sectional view of a substrate holding support unit (61) that holds and supports a substrate (5).

[0031] The pressurized areas (64a, 64b, 64c) are each connected to a pressure regulating unit including a pressure application unit, such as a pump not shown, through pipes (65a, 65b, 65c), and can independently adjust the pressure of the closed space. By controlling each of the pressures of the closed space, the substrate (5) can be deformed in a curved manner in the Z direction.

[0032] In particular, by setting the height of the outermost partition wall (63a) lower than that of the other multiple partition walls located inside it, it is possible to deform the portion of the pressure area (64a) of the substrate (5) downward toward the outer side. FIG. 3c is a drawing illustrating the deformation state when the pressure of the pressure area (64a) is set to a positive pressure, and illustrates the state in which the portion corresponding to the pressure area (64a) of the substrate (5) is deformed upward toward the outer side.

[0033] Meanwhile, FIG. 3d is a drawing illustrating the deformation state of the substrate (5) when the pressure is set to negative pressure, and illustrates the state in which the part corresponding to the pressure area (64a) of the substrate (5) is deformed downward toward the outer periphery. Note that the number of pressure areas of the substrate holding support unit (61) is three, but the number is not limited to this and can be any number greater than one.

[0034] The substrate moving unit (62) of FIG. 1 may include, for example, a linear motor and may be composed of a plurality of driving systems such as a coarse driving system and a fine driving system. The substrate moving unit (62) may be configured to have a function of adjusting the position of the substrate holding support unit (61) in the Z direction as well as in the X and Y directions. Additionally, the substrate moving unit (62) may be configured to have a function of adjusting the position of the substrate holding support unit (61) in the θ direction (rotation around the Z-axis) and a tilt function for adjusting the inclination of the substrate holding support unit (61).

[0035] For measuring the position of the substrate stage (6), an encoder system is used, for example, consisting of a scale provided in the casing (16) and a head (optical device) provided in the substrate moving unit (62). However, the measurement of the position of the substrate stage (6) is not limited to an encoder system, and an interferometer system consisting of a laser interferometer provided in the casing (16) and a reflective mirror provided in the substrate moving unit (62) may be used.

[0036] The off-axis alignment measurement system (9) and the alignment measurement system (10) perform preliminary alignment measurement to measure the relative positions of each shot within the mold (3) and the substrate (5). The control unit (14) uses the off-axis alignment measurement system (9) and the alignment measurement system (10) to measure the positions of the substrate (5) and the mold (3) individually by referring to the device coordinates. The alignment measurement system (10) measures the position of the mold (3) by referring to the position of the alignment measurement system (10) by observing the mold-side mark.

[0037] Meanwhile, the substrate holding support unit (61) that holds and supports the substrate (5) moves to a position directly below the off-axis alignment measurement system (9), and the off-axis alignment measurement system (9) measures a plurality of marks on the substrate (5). In this way, the position of each shot within the substrate (5) is measured by referring to the substrate holding support unit (61), and statistical processing (global alignment) is performed to estimate the position coordinates of all shot areas on the substrate (5).

[0038] The alignment measurement system (10) measures the positional misalignment in the X-axis and Y-axis directions of the alignment mark formed on the substrate (5) and the alignment mark formed on the mold (3). Based on the measured positional misalignment, the position of the substrate stage (6) can be adjusted.

[0039] The charging monitor (11) is a camera that observes the contact state between the pattern unit (3a) and the imprint material supplied to the shot area on the substrate (5). By observing the contact state between the pattern unit (3a) and the substrate through the imprint material, the location of defects caused by particles or incomplete charging is identified. The charging monitor (11) includes a light source, an imaging element, an optical system, and a processing unit (all not shown). As the light source of the charging monitor (11), an LED or the like that emits light having a wavelength that the imprint material is not sensitive to is used, and as the imaging element, a CMOS image sensor or the like is used.

[0040] The optical system includes an illumination optical system that uniformly illuminates an area including a shot area on a substrate (5) with light from a light source, and an imaging optical system that optically conjugates the substrate (5) and the imaging element. The light emitted from the light source passes through an optical member (22) placed in the light path of ultraviolet light, passes through a mold, and illuminates the shot area.

[0041] Note that the imprint device (1) can measure the distance to the upper surface of the substrate (5) by a height measuring device, which is not illustrated. The height measuring device may be an external device outside the imprint device (1). In that case, data measured by the height measuring device as an external device may be stored in memory and used by the imprint device (1).

[0042] The control unit (14) is composed of a computer including, for example, a CPU, memory, etc., and collectively controls each part of the imprint device (1) according to a computer program stored in memory. By controlling the operation, adjustment, etc., of each part of the imprint device (1), the control unit (14) transfers the pattern unit (3a) of the mold (3) to the imprint material on the substrate.

[0043] The console unit (15) includes a computer including input devices such as a keyboard and mouse and a display, and is an interface for sharing information between the imprint device (1) (control unit (14)) and the user. The console unit (15) transmits (outputs) information regarding imprint processing input by the user to the control unit (14).

[0044] Information regarding the imprint processing entered into the console unit (15) can be recorded in the computer as recipe parameters or logs and can be checked before and after the imprint processing.

[0045] In the first embodiment, the console unit (15) also functions as a user interface for adjusting the pressure of a plurality of pressurized areas (64a, 64b, 64c). In addition, in the first embodiment, the control unit (14) functions as an acquisition unit for acquiring the pressure of a plurality of pressurized areas (64a, 64b, 64c) input to the console unit (15).

[0046] Note that the control unit (14) may be configured integrally with other parts of the imprint device (1) (in a common casing) or configured separately from other parts of the imprint device (1) (in a different casing).

[0047] Here, the problem solved in the first embodiment is described using FIGS. 4a through 4f. Note that FIGS. 4a through 4f are drawings for explaining the relationship between the substrate position relative to the substrate holding support unit, the pressure of the pressurized area (64a), and the overlap error.

[0048] When placing a substrate on a substrate holding support unit by a substrate return hand based on the substrate position measured by the pre-alignment unit (7), a position misalignment may occur depending on the position measurement precision of the pre-alignment unit (7). When a position misalignment occurs, as shown in FIG. 3d, the height of the outermost partition wall of the substrate holding support unit is lower than other partition walls, so the position and amount of deformation of the substrate may differ.

[0049] FIG. 4a is a cross-sectional view illustrating a state in which the pressure in the pressurized area (64a) is set to B1 when the substrate is placed at an ideal center with respect to the substrate holding support unit. As shown in FIG. 4a, when the substrate is placed at an ideal center with respect to the substrate holding support unit, the positional misalignment amount (A1) is set, and in this case, the pressure (B1) in the pressurized area (64a) is set so that the overlap error becomes the overlap error (C1) as a reference.

[0050] In this case, bending of the substrate by Δ occurs with respect to the neutral plane of the substrate. FIG. 4d is an enlarged view of the peripheral shot area (52) shown in FIG. 2 in the case of the state shown in FIG. 4a, and the substrate (5) is deformed in the direction of the arrow as shown in FIG. 4d, and the obtained overlap error is C1.

[0051] Meanwhile, FIG. 4b is a cross-sectional view illustrating a state in which the pressure in the pressurized area (64a) is set to B1 while the position of the substrate on the substrate holding support unit is offset (A2) by a positive amount (ΔA). As shown in FIG. 4b, when the position of the substrate on the substrate holding support unit is offset (A2) by a positive amount (ΔA) and the same pressure as the pressure (B1) in FIG. 4a is applied thereto, the amount of bending becomes Δ', and as shown in FIG. 4e, the deformation of the substrate becomes smaller.

[0052] Figure 4e is an enlarged view of the surrounding shot area (52) in the case of the state shown in Figure 4b, and note that the overlap error becomes C1' after changing from the overlap error (C1) as a reference shown in Figure 4d. Even when the pressure on the substrate is determined in advance according to the overlap error and curvature of the substrate, the overlap error may change due to the misalignment of the substrate in this way.

[0053] Accordingly, in the first embodiment, a correction table is obtained in advance that represents the relationship between the positional misalignment amount for each shot area, the pressure on the substrate, and the overlap precision between the substrate and the mold. Then, after the substrate supply step, the positional misalignment amount is calculated, and the pressure on the substrate is determined from the positional misalignment amount and the correction table. In this way, even when there is positional misalignment of the substrate, a pressure that minimizes the overlap precision can be determined.

[0054] FIG. 4c is a cross-sectional view illustrating a state in which the pressure of the pressurized area (64a) is set to B2 while the position of the substrate on the substrate holding support unit has a misalignment (A2) of ΔA. FIG. 4f is an enlarged view of the peripheral shot area (52) in the case of FIG. 4c, in which the overlap error (C2) is substantially the same as the overlap error (C1) as a reference.

[0055] That is, as shown in FIG. 4c, even when the position of the substrate relative to the substrate holding support unit has a misalignment of ΔA, the pressure of the pressure area (64a) is set to B2 so that the deformation (bending) of the substrate becomes the same as the state of FIG. 4a and FIG. 4d. Thus, the reduction of the overlap error can be suppressed.

[0056] Next, FIG. 5 is a flowchart for explaining the imprint processing performed by the imprint device according to the first embodiment, and the imprint processing performed by the imprint device (1) is explained with reference to FIG. 5. Note that the operation of each step of the flowchart of FIG. 5 is performed by the computer in the control unit (14) executing a computer program stored in memory.

[0057] In step S101 of Fig. 5, the relationship between the positional misalignment amount of the substrate, the pressure on the substrate, and the overlap error is measured in advance, and a correction table is obtained.

[0058] In step S101, the position at which the substrate is returned to the substrate holding support unit is changed based on off-axis alignment measurement, and the pressure on the substrate is changed at that position and an imprint is performed.

[0059] For example, first, the substrate is placed by setting the positional misalignment amount (A1) of the substrate as Condition 1, and then the pressure on the substrate is set to pressure (B1), and an imprint is performed. After the imprint, the substrate is superimposed and measured, and the superposition error (C1) is obtained. The superposition error obtained here is obtained by measuring a plurality of superposition measurement marks placed in the shot area. That is, the superposition error in the first embodiment is the superposition error for each shot area.

[0060] Next, as a second condition, the pressure is set to a different pressure (B2), an imprint is performed, and the overlap error (C2) is obtained. In this way, the relationship between multiple pressures and the overlap error is obtained.

[0061] Next, the positional misalignment of the substrate is changed to A2, the substrate is repositioned, and the pressure is changed to multiple pressures as in the case of A1. Imprinting is performed under each pressure, and the relationship with the overlap error is obtained.

[0062] In this way, in step S101, a correction table based on the relationship between the positional misalignment amount of the substrate, the pressure on the substrate, and the overlap error is obtained.

[0063] FIG. 6 is a drawing illustrating an example of a correction table obtained in step S101 according to the first embodiment. In the first embodiment, it is described that the correction table is obtained based on an experiment, but it should be noted that the correction table can be obtained through simulation. It should be noted that while the correction table can be used commonly by each imprint device, individual correction tables can be obtained individually by taking into account individual differences in the flatness of the chuck periphery and differences in adsorption pressure.

[0064] Here, step S101 functions as an acquisition step (acquisition unit) that pre-acquires the relationship between the positional misalignment amount of the substrate relative to the substrate holding support unit, the holding support force (pressure) applied to at least a part of the substrate to hold and support the substrate, and the overlap error between the substrate and the pattern unit.

[0065] In step S102, when changing the mold, the mold (3) is brought into the imprint device (1). Specifically, the mold (3) is brought (returned) to the part below the mold holding support unit (41) of the imprint device (1) by a mold return mechanism (not shown), and the mold holding support unit (41) holds and supports the mold (3).

[0066] In step S103, a substrate (5) is introduced into the imprint device (1). Based on the position where the substrate (5) is mounted, which is detected by the pre-alignment unit (7), the substrate (5) is placed on the substrate holding support unit (61) by the substrate transport hand.

[0067] Step S104 is a step for obtaining the amount of positional misalignment when the substrate is placed on the substrate holding support unit, and functions as a measurement step (measurement unit) for measuring the amount of positional misalignment of the substrate relative to the substrate holding support unit. In the first embodiment, the amount of positional misalignment of the substrate relative to the substrate holding support unit is measured based on the result obtained by the off-axis alignment measurement system (9) measuring the alignment mark placed on the substrate.

[0068] A plurality of shot positions within the substrate (5) are measured by referencing the position of the substrate holding support unit (61), and statistical processing (global alignment) is performed to estimate the position coordinates of all shot areas on the substrate (5). By doing so, the amount of positional misalignment of the substrate (5) with respect to the substrate holding support unit (61) can be obtained.

[0069] In step S105, the substrate (5) is positioned below the coating unit (8) (the supply location of the imprint material). Specifically, the substrate moving unit (62) causes the substrate holding and supporting unit (61) holding and supporting the substrate (5) to move so that the target shot area of ​​the substrate (5) is located below the coating unit (8). Then, in step S106, the coating unit (8) applies the imprint material to the target shot area of ​​the substrate (5).

[0070] In step S107, the substrate (5) is positioned below the mold (3). Specifically, the substrate moving unit (62) causes the substrate holding and supporting unit (61) holding and supporting the substrate (5) to move so that the target shot area of ​​the substrate (5) supplied with the imprint material is positioned below the pattern unit (3a) of the mold (3).

[0071] In step S108, the mold (3) and the imprint material on the substrate (5) are brought into contact with each other. That is, the mold moving unit (42) causes the mold (3) to move in the -Z direction so that the pattern unit (3a) of the mold (3) and the imprint material on the target shot area on the substrate (5) come into contact with each other.

[0072] In step S109, the alignment measurement system (10) measures the positional misalignment in the X-axis and Y-axis directions between the alignment mark formed on the substrate (5) and the alignment mark formed on the mold (3). Based on the measured positional misalignment, the substrate stage (6) is driven finely to position the mold (3) and the substrate (5) relative to each other.

[0073] In step S110, the shape difference between the pattern unit (3a) of the mold (3) and the target shot area of ​​the substrate (5) is corrected. Additionally, based on the correction table obtained in step S101 and the positional misalignment amount of the substrate obtained in step S104, the pressure of the pressure area (64a, 64b, 64c) is changed so that the shape of the pattern unit (3a) and the shape of the target shot area match each other.

[0074] Specifically, the amount of positional deviation measured in step S104 is compared with the correction table obtained in step S101, and the pressure that minimizes the overlap error at that position is obtained as the optimal value. In addition, the pressure of the pressurized areas (64a, 64b, 64c) is adjusted to the optimal value accordingly. That is, pressure adjustment is performed to minimize the overlap error for each shot area.

[0075] Here, step S110 functions as a control step (control unit) that controls the holding support force to reduce the overlap error between the substrate and the pattern unit based on the measured positional misalignment amount and the correction table acquired in step S101.

[0076] Note that if the overlap error between the substrate and the pattern unit in the correction table is assumed to be the amount of warping of the outer circumference of the substrate (measured by a sensor in the device), for example, the processing of step S101 may be performed before or after step S104. In that case, in step S110, correction can be performed to minimize the amount of warping of the outer circumference of the substrate based on the correction table.

[0077] It is noted that based on a correction table, the relationship between the positional misalignment amount of the substrate, the pressure on the substrate, and the overlap error can be expressed as an approximation, and the pressure that minimizes the overlap error can be calculated using the approximation, and the calculated pressure can be used as a target value. That is, in step S101, the relationship between the positional misalignment amount of the substrate relative to the substrate holding support unit, the holding support force applied to at least a part of the substrate to hold and support the substrate, and the overlap error between the substrate and the pattern unit can be obtained as an equation instead of a correction table.

[0078] It should be noted that when the amount of deformation of the substrate is changed by controlling the pressure (holding force) on the substrate, the alignment offset between the shot area and the pattern unit may also change. The alignment offset referred to herein includes, for example, at least one of alignment, scaling, rotation, skew, or trapezoidal offset.

[0079] Alignment offset is the offset of positioning in the XY direction between the mold and the substrate, and magnification offset is the relative contraction or expansion offset between the pattern unit of the mold and the shot area on the substrate. Rotation offset is the relative orientation offset around the Z-axis, and skew offset is the relative orthogonal offset between the pattern unit of the mold and the shot area on the substrate.

[0080] These alignment offsets are offsets that occur due to differences between the optical system of the alignment measurement system (10) and the device (overlap measurement device) that measures overlap precision. Generally, the alignment offset is obtained by referring to the overlap measurement device, the obtained offset is input into the console unit (15), and adjustment is performed to minimize the overlap error by performing an imprint.

[0081] When the substrate is deformed in step S110 based on the amount of positional misalignment of the substrate in step S104, the alignment offset may also change. Accordingly, in the first embodiment, the alignment offset between the shot area and the pattern unit is also corrected according to the control of the pressure (holding force) in step S110.

[0082] That is, step S110 also functions as a correction step (correction unit) that corrects the alignment offset between the shot area and the pattern unit.

[0083] A method for calculating the change in alignment offset is explained using FIG. 4. As shown in FIG. 4a, the alignment offset is adjusted at the positional misalignment amount (A1) and pressure (B1) of the substrate, and the overlap error is C1. Meanwhile, as shown in FIG. 4c, when the positional misalignment amount is A2 and the pressure is B2, the overlap error is C2.

[0084] Accordingly, the difference between C1 and C2 is calculated, the alignment offsets included in the difference (components such as alignment, scaling, rotation, skew, trapezoid, etc.) are calculated, and each of these is added to the already input alignment offset. By doing so, even when the alignment offset changes in response to the correction of the amount of deformation of the substrate due to pressure on the substrate, imprinting can be performed without reducing the superposition precision.

[0085] In step S111, a pattern is formed in the shot area by curing the imprint material while the mold (3) and the imprint material applied to the shot area on the substrate are in contact with each other. Specifically, the imprint material is cured by the irradiation unit (2) irradiating light onto the imprint material that the pattern unit (3a) of the mold (3) contacts.

[0086] In step S112, the mold (3) is separated from the cured imprint material on the substrate. Specifically, the mold moving unit (42) causes the mold (3) to move in the +Z direction so that the mold (3) is peeled off from the imprint material on the substrate, that is, so that the distance between the mold (3) and the substrate (5) increases.

[0087] In step S113, it is determined whether there is a target shot area to continue forming a pattern. If it is determined that there is no target shot area (No in step S113), in step S114, a substrate return mechanism (not shown) removes the substrate from the imprint device (1). If it is determined that there is a target shot area (Yes in step S113), steps S105 to S113 are repeated.

[0088] Here, steps S105 to S113 function as a pattern forming step (pattern forming unit) that forms a pattern using a pattern unit (3a) in a shot area of ​​a substrate (5) held and supported by a substrate holding support unit (61).

[0089] Note that in order to correct the radial distortion of the substrate (5), the pressure area of ​​the substrate holding support unit (61) is divided into concentric circles, but the shape of the division is not limited to this. For example, if the peripheral distortion of the substrate (5) is large, the partitions of the substrate holding support unit may be arranged radially, and the pressure area may be divided peripherically.

[0090] Alternatively, a combination of radially arranged partitions and concentrically arranged partitions can divide the pressure area, and the pressure area of ​​the substrate holding support unit (61) may include a grid-shaped area. In addition, although the peripheral shot area, which is more prone to deformation, was described as an example in the first embodiment, the present invention is not limited thereto, and similar correction can be performed on the inner shot area of ​​the substrate (5).

[0091] As described above, in the first embodiment, when, for example, the pattern unit (3a) and the imprint material on the substrate are in contact with each other, the pressure of the pressure area of ​​the substrate holding support unit (61) is controlled according to the amount of positional misalignment of the substrate, thereby correcting the shape difference between the pattern unit (3a) and the shot area on the substrate (5). Thus, the overlap precision can be improved.

[0092] <Second Embodiment>

[0093] FIG. 7 is a drawing illustrating a method for measuring the positional misalignment of a substrate according to a second embodiment of the present invention, and the second embodiment of the present invention is described based on FIG. 7.

[0094] In the first embodiment, an example was described in which an alignment mark placed on a substrate is measured by an off-axis alignment measurement system (9), and based on the results obtained by performing statistical processing, the amount of positional misalignment of the substrate relative to the substrate holding support unit is calculated. In the second embodiment, a charging monitor (11) is used to calculate the relative positional misalignment between the substrate (5) and the substrate holding support unit. Note that since the operation of the imprint device and imprint processing in the second embodiment is the same as in the first embodiment, only different items are described.

[0095] FIG. 7 shows the state of a substrate (5) placed on a substrate holding support unit (61) viewed from the +Z direction, and in step S104, the substrate moving unit (62) moves the substrate holding support unit (61) so that the substrate holding support unit (61) holding the substrate (5) is positioned below the charging monitor (11). Then, the substrate moving unit (62) is moved to reach the observation field of view (11a) of the charging monitor (11).

[0096] At this time, the center (5a) of the substrate (5) and the center (61a) of the substrate holding support unit (61) are each calculated from the acquired image, and the positional misalignment amount (ΔCx, ΔCy) is calculated. Regarding the calculation of the center, for example, the center can be obtained as the center of a circle by detecting the edges of the substrate (5) and the substrate holding support unit (61) in the acquired viewing field (11a) through image processing. It should be noted that, considering the external shape tolerance of the substrate (5) and the manufacturing error of the substrate holding support unit (61), it is preferable to acquire images of multiple positions, such as the viewing field (11b) and the viewing field (11c), with the charging monitor (11) and calculate the center.

[0097] Based on the positional misalignment amount obtained in this way and the correction table obtained in step S101, the pressure of the pressurized areas (64a, 64b, 64c) in step S110 is changed, and the shape difference between the pattern unit (3a) of the mold (3) and the target shot area on the substrate (5) is corrected. Accordingly, in the second embodiment, the positional misalignment amount can be detected with higher precision and the overlap precision can be further improved.

[0098] It should be noted that the lithography device according to the above embodiment includes an exposure device that irradiates light onto a pattern unit, such as a patterned reticle (mask or plate), and projects the pattern onto a shot area on a wafer using light from the reticle. Additionally, the lithography device according to the above embodiment is included as part of a lithography system.

[0099] In addition, the lithography system includes a step of developing a substrate (wafer, glass substrate, etc.) on which a pattern is formed by a lithography device according to the above embodiment, and the lithography system can manufacture an article by processing the developed substrate in other known steps. It should be noted that other known steps include etching, resist stripping, dicing, bonding, packaging, etc.

[0100] According to the method for manufacturing an article using a lithography device of the embodiment described above, the overlap error can be reduced compared to the prior art, so high-quality articles can be manufactured.

[0101] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims should be interpreted in the broadest sense to include structures and functions equivalent to all such variations.

[0102] In addition, as part or all of the control according to the embodiment, a computer program that realizes the function of the above-described embodiment may be supplied to the lithography device through a network or various storage media. Furthermore, the computer (or CPU, MPU, etc.) of the lithography device may be configured to read and execute the program. In such a case, the program and the storage medium storing the program constitute the present invention.

[0103] This application claims the benefit of Japanese Patent Application No. 2022-072974, filed on April 27, 2022, the entirety of which is incorporated herein by reference.

Claims

Claim 1 A lithography device comprising: a pattern forming unit configured to form a pattern using a mold pattern unit on a shot area on a substrate held and supported by a substrate holding and supporting unit; an acquisition unit configured to acquire a relationship between the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit, a holding and supporting force applied to at least a part of the substrate to hold and support the substrate, and an overlap error between the substrate and the pattern unit; a first measurement unit configured to measure the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit; a second measurement unit configured to measure the amount of positional misalignment of the substrate relative to the mold; a substrate moving unit configured to move the substrate holding and supporting unit; and a control unit configured to control the holding and supporting force applied to at least a part of the substrate to hold and support the substrate to reduce the overlap error between the substrate and the pattern unit based on the amount of positional misalignment of the substrate relative to the mold measured by the first measurement unit and the relationship acquired by the acquisition unit, wherein the control unit based on the amount of positional misalignment of the substrate relative to the mold measured by the second measurement unit A lithography apparatus configured to control the position of the substrate holding support unit using the substrate moving unit. Claim 2 A lithography device according to claim 1, wherein the overlap error between the substrate and the pattern unit is an overlap error for each shot area. Claim 3 In paragraph 2, the control unit is a lithography device that controls the holding support force to reduce the overlap error for each shot area. Claim 4 A lithography apparatus according to claim 1, wherein the substrate holding support unit includes a plurality of pressure areas for pressing and holding support the substrate, and the control unit is configured to control the pressure of the plurality of pressure areas based on the amount of positional misalignment of the substrate relative to the substrate holding support unit. Claim 5 In claim 1, the pattern forming unit comprises an imprint material applied to a shot area on the substrate and The above A lithography device for forming the pattern in the shot area by curing the imprint material while the molds are in contact with each other. Claim 6 In claim 1, the first measurement unit is a lithography device that is an off-axis alignment measurement system. Claim 7 A lithography apparatus according to claim 4, wherein the plurality of pressure zones are divided into concentric circles, and the height of the outermost partition among the partitions dividing the plurality of pressure zones is configured to be lower than the height of the other partitions. Claim 8 In paragraph 4, the plurality of pressure regions comprises a lithography device including regions divided into a grid shape. Claim 9 A lithography apparatus according to claim 1, further comprising a correction unit that corrects an alignment offset between the shot area and the pattern unit in conjunction with the control of the holding support force applied by the control unit. Claim 10 A lithography method comprising: a forming step of forming a pattern using a pattern unit of a mold on a shot area on a substrate held and supported by a substrate holding and supporting unit; an acquisition step of acquiring in advance a relationship between the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit, a holding and supporting force applied to at least a part of the substrate to hold and support the substrate, and an overlap error between the substrate and the pattern unit; a first measurement step of measuring the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit; a second measurement step of measuring the amount of positional misalignment of the substrate relative to the mold; a substrate moving step of moving the substrate holding and supporting unit by a substrate moving unit; and a control step of controlling the holding and supporting force applied to at least a part of the substrate to hold and support the substrate to reduce the overlap error between the substrate and the pattern unit based on the amount of positional misalignment of the substrate relative to the mold measured in the first measurement step and the relationship acquired in the acquisition step of acquiring the relationship, and controlling the position of the substrate holding and supporting unit using the substrate moving unit based on the amount of positional misalignment of the substrate relative to the mold measured in the second measurement step. Claim 11 A method for manufacturing an article, comprising: a forming step of forming a pattern using a pattern unit of a mold on a shot area on a substrate held and supported by a substrate holding and supporting unit; an acquisition step of acquiring a relationship between the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit, a holding and supporting force applied to at least a part of the substrate to hold and support the substrate, and an overlap error between the substrate and the pattern unit; a first measurement step of measuring the amount of positional misalignment of the substrate relative to the substrate holding and supporting unit; a second measurement step of measuring the amount of positional misalignment of the substrate relative to the mold; and a substrate moving step of moving the substrate holding and supporting unit by a substrate moving unit. A method for manufacturing an article comprising: a control step for controlling a holding support force applied to at least a portion of a substrate to hold and support the substrate in order to reduce an overlap error between the substrate and the pattern unit based on the positional misalignment amount of the substrate relative to the mold measured in the first measurement step and the relationship acquired in the acquisition step; a second measurement step for controlling the position of the substrate holding support unit using the substrate moving unit based on the positional misalignment amount of the substrate relative to the mold measured in the second measurement step; a forming step for forming the pattern on the substrate; and a developing step for developing the substrate on which the pattern is formed in the pattern forming step. Claim 12 A lithography apparatus according to claim 1, wherein the control unit is configured to control the holding support force so as to reduce the amount of bending of the outer circumference of the substrate. Claim 13 A lithography device according to claim 1, wherein the first measuring unit is configured to measure the position of the substrate before measuring the amount of positional misalignment of the substrate relative to the substrate holding support unit. Claim 14 In paragraph 4, the lithography apparatus is configured such that the control unit controls the pressure of the plurality of pressure zones while the pattern unit and the imprint material on the substrate are in contact with each other.

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