Imprint device and manufacturing method of article

Abstract

To provide an imprint device which is advantageous for forming a pattern on a substrate by highly accurately calculating a position of a mold.SOLUTION: An imprint device comprises: a mold holding section; a substrate holding section; a measurement section which acquires a measured value by measuring a distance to a surface of a mold held by the mold holding section; a drive section which drives the measurement section in a direction along a reference surface to be a reference of driving the substrate holding section; and a control section which performs measurement processing for measuring a distance using the measurement section regarding a plurality of locations of a structure provided on the surface of the mold while driving the measurement section by means of the drive section and for calculating a position of the mold in the direction from measured values regarding the plurality of locations. The measured value includes a cyclic error caused by the distance between the measurement section and the mold. Before performing the measurement processing, the control section adjusts a position of the mold holding section in a direction across the reference surface in such a manner that the distance measured by the measurement section is settled within a range in which the measured value is insensible with respect to the cyclic error.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] As the demand for miniaturization of semiconductor devices and MEMS (Micro Electro Mechanical Systems) increases, imprinting technology is attracting attention in addition to conventional photolithography technology. Imprinting technology is a microfabrication technology in which an imprinting material placed (supplied) on a substrate is shaped with a mold to form a pattern of the imprinting material on the substrate. With imprinting technology, it is possible to form fine structures on the order of a few nanometers on a substrate.

[0003] In imprint technology, a photocuring method is known as one of the methods for hardening an imprint material. In an imprint device that employs the photocuring method, the imprint material arranged on a substrate is brought into contact with a mold and irradiated with light (such as ultraviolet light) to harden the imprint material, and the mold is then separated from the hardened imprint material to form a pattern of the imprint material on the substrate.

[0004] A convex portion called a mesa portion is formed on a mold that is generally used in an imprint apparatus, and a pattern is formed on the mesa portion. In such an imprint apparatus, a technology has been proposed to specify the position of the mesa portion of the mold by measuring the distance from a measuring device such as a sensor to the mold (surface) while driving the measuring device in a plane (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-62286 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in conventional technology, if the position repeatability immediately after the measurement instrument is driven is low, the position of the mesa portion (convex portion) of the mold cannot be determined with high accuracy even if the position of the measurement instrument during operation is stable. This is mainly due to the following three factors. The first factor is that a deviation (offset) other than the position difference occurs in the measurement value obtained by the measurement instrument due to the phase difference of the cyclic error. The second factor is that if the distance within the measurement range (spot) of the measurement instrument is not uniform due to steps such as mesa portions present in the mold, fraud (error) of the measurement value occurs due to stray light. The third factor is that the fraud included in the measurement value varies depending on the phase of the cyclic error.

[0007] The present invention has been made in consideration of the problems with the conventional technology, and has an exemplified object to provide an imprint apparatus that is advantageous for determining the position of a mold with high accuracy and forming a pattern on a substrate. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, an imprinting apparatus as one aspect of the present invention is an imprinting apparatus that forms a pattern of imprint material on a substrate using a mold, and includes: a mold holding unit that holds and drives the mold; a substrate holding unit that holds and drives the substrate; a measurement unit that measures the distance to a surface of the mold held by the mold holding unit to obtain a measurement value; a drive unit that drives the measurement unit in a direction along a reference plane that serves as a reference for driving the substrate holding unit; and a control unit that performs a measurement process in which the measurement unit measures the distance for multiple locations of a structure provided on the surface of the mold while driving the measurement unit with the drive unit, and determines the position of the mold in the direction from the measurement values ​​for the multiple locations, wherein the measurement value includes a cyclic error caused by the distance between the measurement unit and the mold, and the control unit adjusts the position of the mold holding unit in a direction intersecting the reference plane before performing the measurement process so that the distance measured by the measurement unit falls within a distance range corresponding to a range in which the measurement value is insensitive to the cyclic error.

[0009] Further objects or other aspects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Effect of the Invention

[0010] According to the present invention, for example, it is possible to provide an imprint apparatus that is advantageous for determining the position of a mold with high accuracy and forming a pattern on a substrate. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing a configuration of an imprint apparatus according to one aspect of the present invention. [Diagram 2] 11 is a flowchart for explaining the operation of the imprint apparatus. [Diagram 3] 11A and 11B are diagrams showing the configuration of a mesa portion of a mold. [Figure 4] 4 is a flowchart for explaining a measurement process in detail. [Diagram 5]FIG. 4 is a diagram showing an example of waveform data. [Figure 6] FIG. 13 is a diagram for explaining a cyclic error. [Figure 7] 11A and 11B are diagrams for explaining a procedure for making an adjustment so that a position shift does not occur. [Figure 8] FIG. 4 is a diagram showing an example of waveform data. [Figure 9] 4 is a flowchart for explaining a measurement process in detail. [Figure 10] 1A to 1C are diagrams for explaining a method for manufacturing an article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0013] 1 is a schematic diagram showing the configuration of an imprinting apparatus 1 according to one aspect of the present invention. The imprinting apparatus 1 forms a pattern of the imprinting material on the substrate by using a mold to shape the imprinting material on the substrate. In this embodiment, the imprinting apparatus 1 brings the mold into contact with the imprinting material arranged (supplied) on the substrate, and applies energy for curing to the imprinting material, thereby forming a pattern of a cured material to which the pattern of the mold has been transferred.

[0014] The imprint apparatus 1 is, for example, employed in a lithography process, which is a manufacturing process for devices such as semiconductor elements, liquid crystal display elements, and magnetic storage media as articles, and is embodied as a lithography apparatus that forms a pattern on a substrate. The imprint apparatus 1 is also embodied as a mold fabrication apparatus that forms a pattern on a convex portion (mesa portion) of a blank mold in order to fabricate (manufacture) a replica mold (replica mold) having the same pattern from a master mold (master mold). Hereinafter, in this embodiment, the imprint apparatus 1 will be described as a mold fabrication apparatus. The replica mold fabricated by the mold fabrication apparatus is used as a mold in another imprint apparatus, and is used when performing an imprint process on a substrate.

[0015] The imprint material is a material (curable composition) that is cured by applying energy for curing. The energy for curing may be electromagnetic waves, heat, or the like. The electromagnetic waves include, for example, light having a wavelength selected from the range of 10 nm to 1 mm, specifically infrared rays, visible rays, ultraviolet rays, and the like.

[0016] The curable composition is a composition that is cured by irradiation with light or by heating. The photocurable composition that is cured by irradiation with light contains at least a polymerizable compound and a photopolymerization initiator, and may further contain a non-polymerizable compound or a solvent, as necessary. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, a polymer component, and the like.

[0017] The imprint material may be applied in the form of a film on the substrate by a spin coater or a slit coater. The imprint material may also be applied in the form of droplets, or in the form of islands or a film formed by connecting a plurality of droplets, by a liquid jet head. The viscosity of the imprint material (at 25° C.) is, for example, 1 mPa·s or more and 100 mPa·s or less.

[0018] The substrate may be made of glass, ceramics, metal, semiconductor, resin, etc., and may have a member made of a material different from that of the substrate formed on its surface as required. Specifically, the substrate may be made of a silicon wafer, a compound semiconductor wafer, quartz glass, etc.

[0019] In this specification and the accompanying drawings, directions are shown in an XYZ coordinate system in which the direction parallel to the surface on which the substrate is placed is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X-direction, Y-direction, and Z-direction, respectively, and rotation around the X-axis, Y-axis, and Z-axis are θX, θY, and θZ, respectively.

[0020] The imprint apparatus 1 employs a photo-curing method for curing the imprint material by irradiating the imprint material with light such as ultraviolet light, but the method is not limited to this.

[0021] 1, the imprint apparatus 1 has an irradiation section 2, a mold holding section 4 that holds a mold M, a control section 5, an alignment measurement system 6, a supply section 7 that supplies an imprint material 14, a substrate measurement section 8, and a mold measurement section 9. The imprint apparatus 1 also has a stage 110 (substrate holding section) that holds a substrate W, a movable section 120, and a surface plate 130. Furthermore, the imprint apparatus 1 has a mold transport device (not shown) that transports the mold M, and a substrate transport device (not shown) that transports the substrate W.

[0022] In the imprint process, the irradiation unit 2 irradiates light 17 (ultraviolet rays) that hardens the imprint material 14 on the substrate through the mold M. The irradiation unit 2 includes, for example, a light source and an optical element for adjusting the light 17 emitted from the light source to an appropriate light to be irradiated onto the imprint material 14.

[0023] The mold M includes a mesa portion Me (protrusion) that protrudes from the surrounding portion on a surface facing the substrate W when held by the mold holding part 4. A pattern (a predetermined concave-convex pattern) to be transferred to the substrate W is formed on the surface of the mesa portion Me.

[0024] The mold holding unit 4 includes a holding mechanism that holds the mold M, and a drive mechanism that drives the mold M held by the holding mechanism in the Z direction. The mold holding unit 4 may also include a drive mechanism that tilts the mold M in accordance with the tilt of the mold M and / or the substrate W, and a drive mechanism that drives the mold M in the X and Y directions.

[0025] The alignment measurement system 6 is a scope for detecting (observing) an alignment mark on the substrate W held by the stage 110 (chuck 111) and identifying the position of the substrate W (for example, the position of each shot area on the substrate).

[0026] The supply unit 7 includes a dispenser that dispenses the imprint material 14, and supplies and arranges the imprint material 14 on the substrate.

[0027] The substrate measuring unit 8 has a function of measuring the substrate W. The substrate measuring unit 8 includes a measuring device (distance sensor) that measures the distance in the Z direction from the substrate measuring unit 8 to the surface of the substrate W. The height (position in the Z direction) of the surface of the substrate W can be obtained based on the measurement results obtained by the substrate measuring unit 8. In addition, it is also possible to measure the shape of the surface of the substrate W by measuring each position of the surface of the substrate W by the substrate measuring unit 8 while driving the stage 110 that holds the substrate W along the reference surface 130A.

[0028] In this embodiment, the mold measurement unit 9 is provided on (the upper surface of) the stage 110. The mold measurement unit 9 employs a spectroscopic interference system capable of measuring the displacement of the measurement target in a non-contact manner, and measures the distance from the mold measurement unit 9 to the surface of the mold M (hereinafter referred to as "gap amount"). The mold measurement unit 9 includes, for example, a measurement light source (laser light source), an image sensor (distance sensor), and a calculator (analysis mechanism). Light emitted from the measurement light source is reflected by the surface of the mold M to become return light, which is detected by the image sensor. The calculator calculates the gap amount based on the result detected by the image sensor. Examples of measurement methods that can be adopted by the mold measurement unit 9 include a method of measuring the gap amount from the position of return light when light is incident obliquely to the measurement direction, and a method of measuring the gap amount from interference fringes between return light and reference light. Here, the beam spot of the reference light has various shapes such as a circle or an ellipse, and various diameters from 10 μm to 1000 μm. The average of the measurement values ​​within the range of the beam spot diameter becomes the cap amount at the measurement point on the surface of mold M.

[0029] The stage 110 holds the substrate W via a chuck 111. In this embodiment, the substrate W is a blank mold, that is, a replica mold before a pattern is formed. In addition, a stage reference plate 10 is attached (fixed) to the stage 110. The stage reference plate 10 is provided with a mark that can be measured by the alignment measurement system 6.

[0030] The stage 110, together with the movable part 120, is supported by a surface plate 130. In the surface plate 130, a surface that supports the stage 110 and the movable part 120 is referred to as a reference surface 130A (guide surface). The reference surface 130A of the surface plate 130 is a surface parallel to the XY plane.

[0031] As described above, in this embodiment, the mold measurement unit 9 is provided on the upper surface of the stage 110. Therefore, by driving the stage 110 along the reference surface 130A (XY plane), the mold measurement unit 9 can measure each position on the surface of the mold M. However, the mold measurement unit 9 does not need to be provided on the stage 110, and may be provided on a mechanism different from the stage 110. Even in this case, by providing a drive unit that drives such a mechanism along the XY plane, it becomes possible for the mold measurement unit 9 to measure each position on the surface of the mold M.

[0032] The stage 110 is configured to be able to drive above the reference surface 130A while holding the substrate W with the chuck 111. The stage 110 includes a stage bottom driving mechanism 112 provided on a surface facing the reference surface 130A. The stage bottom driving mechanism 112 includes an air guide (not shown) and ejects gas onto the reference surface 130A of the base plate 130 to form a gap between the stage 110 and the reference surface 130A and support the stage 110 in the Z direction. In the imprint apparatus 1, it is necessary to drive the stage 110 at high speed and with high accuracy with a large stroke in the X direction and the Y direction while eliminating friction and wear between the stage 110 and the base plate 130 (reference surface 130A). Therefore, in this embodiment, the stage 110 is floated several μm to several tens of μm above the base plate 130 by the stage bottom driving mechanism 112 (air guide). Furthermore, the stage bottom driving mechanism 112 may include an adsorption mechanism (not shown) using a cylinder mechanism that utilizes gas, magnets, or fluid pressure to stabilize the position of the stage 110 in the Z direction.

[0033] The movable part 120 drives the stage 110 in the X direction and the Y direction. In this embodiment, the movable part 120 functions as a drive part that drives the mold measurement part 9 via the stage 110. The movable part 120 includes an X guide part 121, a bottom air guide 123, a side air guide 124, a Y linear motor mover 126, a Y linear motor stator 127, and a Y guide part 128. The bottom air guide 123 supports the movable part 120 by ejecting gas to a reference surface 130A of the base plate 130, forming a gap between the movable part 120 and the reference surface 130A. The side air guide 124 ejects gas to the Y guide part 128, forming a gap between the movable part 120 and the Y guide part 128.

[0034] Movable section 120 is driven in the Y direction along Y guide section 128 by Y linear motor mover 126 and Y linear motor stator 127. Along with such driving of movable section 120, stage 110 is also driven in the Y direction.

[0035] The movable part 120 includes an X linear motor mover (not shown) and an X linear motor stator (not shown). The stage 110 is driven in the X direction along the X guide part 121 by the X linear motor mover and the X linear motor stator. Note that the imprint apparatus 1 may have a measuring device (position sensor) that measures the position of the stage 110 in the X and Y directions.

[0036] The control unit 5 is configured as an information processing device (computer) including a CPU, memory, etc. The control unit 5 generally controls each unit of the imprint apparatus 1 to operate the imprint apparatus 1 in accordance with a program stored in the storage unit. The control unit 5 may be configured integrally with the imprint apparatus 1 (in a common housing), or may be configured separately from the imprint apparatus 1 (in a different housing).

[0037] With reference to FIG. 2, the operation of the imprint apparatus 1, specifically, the imprint process for transferring the pattern of the mold M to the substrate W will be described. The imprint process is performed by the control unit 5 controlling each unit of the imprint apparatus 1 in an integrated manner. In the imprint process, the mold measurement unit 9 measures the recessed portions 23a, 23b, 23c, and 23d provided in the mesa portion Me of the mold M, as shown in FIG. 3. The recessed portions 23a to 23d are structures provided on the surface of the mold M, and are configured as concave recesses dug into the surface of the mold M, specifically, the surface of the mesa portion Me. In this embodiment, the mold measurement unit 9 measures the recessed portions 23a to 23d in the Z direction, and the concave shapes of the recessed portions 23a to 23d are used to determine the positions (positional deviations) in the X and Y directions of the mold M (the mesa portion Me). However, it is also possible to obtain the positions of the mold M in the X and Y directions by using other grooves, patterns, shapes, etc. carved into the mesa portion of the mold M or outside the mesa portion, instead of the carved portions 23a to 23d. The depth (carved amount) of the carved portions 23a to 23d is preferably 20 nm or more and 200 nm or less, but is not limited to this and may be, for example, about 1 μm. FIG. 3 is a diagram showing the configuration of the mesa portion Me of the mold M.

[0038] In S101, the mold M is carried into the imprint apparatus 1. Specifically, the mold M is carried into the imprint apparatus 1 by the mold carrying device, and the mold M is held (fixed) by the mold holding unit 4.

[0039] In S102, the dug portions 23a to 23d of the mesa portion Me of the mold M are measured to obtain measurement values ​​(measurement process). First, the stage 110 is driven so that the dug portions 23a to 23d of the mesa portion Me of the mold M can be measured by the mold measurement unit 9. Then, while driving the mold measurement unit 9 by the stage 110 (movable unit 120), the mold measurement unit 9 measures a plurality of locations of the dug portions 23a to 23d provided in the mesa portion Me of the mold M. Specifically, as shown in FIG. 3, the measurement lines (virtual lines) 20a to 20d in the X direction and the measurement lines (virtual lines) 21a to 21d in the Y direction of the dug portions 23a to 23d are measured to determine the positional deviation amounts of the mold M in the X direction and the Y direction. Measured lines 20a and 21a are perpendicular to each other, measured lines 20b and 21b are perpendicular to each other, measured lines 20c and 21c are perpendicular to each other, and measured lines 20d and 21d are perpendicular to each other.

[0040] In S103, it is determined whether all of the dug portions 23a to 23d of the mesa portion Me of the mold M have been measured. If all of the dug portions 23a to 23d have not been measured, the process proceeds to S102. On the other hand, if all of the dug portions 23a to 23d have been measured, the process proceeds to S104. In this embodiment, the measurement lines 20a to 20d and 21a to 21d are each set as the measurement object, but this is not limited thereto. For example, depending on whether the measurement accuracy due to the averaging effect is emphasized or the processing speed is emphasized, it is possible to freely set (specify) one or more measurement objects in each of the X direction and the Y direction from the measurement lines 20a to 20d and 21a to 21d.

[0041] In S104, the amount of positional deviation in the X direction and the Y direction (planar direction) of the mold M (of the mesa portion Me) is determined (specified) based on the measurement value (the amount of deviation in each measured line) and the measurement position information acquired in S102. In this embodiment, as the amount of positional deviation of the mold M, the positional deviation and magnification components of X, Y, and θ of the mold M are determined by the least squares method or the like.

[0042] In S105, the substrate W is carried into the imprint apparatus 1. Specifically, the substrate W is carried into the imprint apparatus 1 by the substrate transport device, and the substrate W is held (fixed) on the stage 110 (chuck 111).

[0043] In S106, the amount of misalignment in the X and Y directions (planar directions) of the substrate W is determined (specified). First, a plurality of alignment marks provided on the substrate W are measured by the alignment measurement system 6. Then, based on the amount of misalignment at each alignment mark and the measured position information, the amount of misalignment in the X and Y directions (planar directions) of the substrate W (positional misalignments and magnification components of X, Y, and θ of the substrate W) is determined (specified) by the least squares method or the like.

[0044] In S107, the imprint material 14 is placed (supplied) on the substrate. Specifically, the supply unit 7 places the imprint material 14 on the substrate (on the shot area of ​​the substrate W) based on the positional deviation amount of the substrate W determined in S105.

[0045] In S108, a pattern is formed on the substrate. First, the mold M is brought into contact with the imprint material 14 arranged on the substrate, and the mold M and the substrate W are aligned based on the amount of positional deviation of the mold M determined in S103. Next, while the mold M is in contact with the imprint material 14 on the substrate, light 17 is irradiated from the irradiation unit 2 to harden the imprint material 14. Then, the mold M is separated from the hardened imprint material 14 on the substrate, thereby forming a pattern of the imprint material 14 (a hardened product of the imprint material 14 to which the pattern of the mold M has been transferred) on the substrate.

[0046] In S109, the substrate W is carried out from the imprint apparatus 1. Specifically, the substrate W held on the stage 110 is carried out to the outside of the imprint apparatus 1 by the substrate carrying device.

[0047] In S110, the mold M is unloaded from the imprint apparatus 1. Specifically, the mold M held by the mold holding unit 4 is transported to the outside of the imprint apparatus 1 by the mold unloading device.

[0048] FIG. 4 is a flowchart for explaining in detail the measurement process (S102) for determining the amount of positional deviation of the mold M in the planar direction.

[0049] In S201, the stage 110 and the mold holding unit 4 are driven to a target position. For example, the stage 110 is driven to a target position where the mold measurement unit 9 is disposed under the measurement start position (end of the measured line) of the measured line to be measured among the measured lines 20a to 20d and 21a to 21d. In addition, the mold holding unit 4 is driven to a target position of the mold holding unit 4 set in consideration of thickness information of the mold M measured and acquired in advance. Note that it is preferable to set the target position of the mold holding unit 4 so that the measurement value acquired by the mold measurement unit 9 does not deviate significantly from a predetermined value (S203). This is because there is a high possibility that the process of S207 described later can be omitted.

[0050] Here, let us consider a case where the process proceeds to S204 without performing the processes of S202, S203, S206, and S207. In S204, the mold measurement unit 9 is driven by the stage 110, and the mold measurement unit 9 measures the gap amount at multiple points (measurement lines) of the dug portions 23a to 23d of the mesa portion Me of the mold M. The operation of driving the mold measurement unit 9 by the stage 110 and measuring the gap amount by the mold measurement unit 9 is repeated from the measurement start position to the measurement end position of the measurement line. This makes it possible to obtain the measurement values ​​at multiple points of the dug portions 23a to 23d of the mesa portion Me of the mold M and the driving position of the stage 110 (mold measurement unit 9) when the multiple measurement values ​​were obtained. The above-mentioned operation can be performed, for example, by a step-and-repeat method in which the step driving of the stage 110 and the measurement of the gap amount are repeated for each measurement point. The above-mentioned operation may be performed by a step-and-scan method in which the gap amount is measured while the stage 110 is driven to perform a scan.

[0051] In measuring the gap amount in S204, the stage 110 is driven in the X direction and the Y direction with the center of the dug portions 23a to 23d of the mesa portion Me of the mold M as a reference. For example, the dimension (measurement range) of the measured line 20a is set to a range obtained by adding a certain measurement distance to the planar dimension of the dug portion 23a in the X direction in order to allow for a positional deviation that occurs when the mold M is held by the mold holding portion 4. If the length of the dug portion 23a in the X direction is 1 mm and the allowable value of the positional deviation that occurs when the mold M is held by the mold holding portion 4 is ±500 μm, the length of the measured line 20a in the X direction is 1 mm ±500 μm × 2 (both sides). If the approximate position of the dug portion 23a is known, the measurement range may be limited to the vicinity of the end of the dug portion 23a. Furthermore, the approximate position of another measured line may be known by using the amount of positional deviation in the X direction measured for a certain measured line.

[0052] As shown in FIG. 3, the measurement values ​​acquired by the mold measurement unit 9 include waveform data 24 and 25. The waveform data 24 and 25 are data showing the relationship between the measurement points of the mesa portion Me of the mold M from the mold measurement unit 9 side and the measurement values ​​(gap amounts) at the measurement points on the measurement lines 20a and 21d, respectively. FIG. 5(a) is a conceptual diagram showing an enlarged view of the waveform data 24. In FIG. 5(a), a plurality of points 30 are further enlarged views of a portion of the waveform data 24. Referring to FIG. 5(a), it can be seen that the waveform data 24 is data obtained by plotting a plurality of measurement values ​​acquired by the mold measurement unit 9 and a plurality of drive positions of the stage 110 when the plurality of measurement values ​​are acquired.

[0053] 4, in S205, the amount of positional deviation in the X and Y directions is determined (specified) for each of the lines to be measured 20a to 20d in the X direction and the lines to be measured 21a to 21d in the Y direction in the dug portions 23a to 23d of the mesa portion Me of the mold M. For example, the apex and center of gravity of the waveform data obtained in S204 are obtained, and the amount of positional deviation in the X and Y directions is determined from the difference (Δd2) from the design position. Specifically, there is a method of approximating the waveform data to a quadratic parabola by the least squares method or the like, and determining the apex position of the quadratic parabola, or a method of determining the center of gravity from a convex portion of the waveform data, but the apex and center of gravity of the waveform data may be obtained by other methods.

[0054] In reality, the waveform data is not symmetrical due to various factors. For example, the step positions cannot be clearly observed near the steps at the ends of the recessed portions 23a to 23d due to the influence of the beam spot diameter of the mold measurement unit 9, and the data changes gradually. In addition, at the steps, some of the light from the mold measurement unit 9 is diffusely reflected, which can cause the measurement value to be misleading, and a depression 26 may occur in the waveform data 24 as shown in FIG. 5(a). This is because the mold measurement unit 9 is composed of a distance sensor (Z direction) and uses the distance sensor to measure the positional deviation of the mold M in the X and Y directions, so the shape of the waveform data is not guaranteed and the data becomes asymmetrical.

[0055] It is also known that when the mold measurement unit 9 measures the gap amount, a nonlinear error that changes periodically according to the optical path amount (distance) from the mold measurement unit 9 to the measurement target, a so-called reclick error, occurs. Fig. 6(a) is a diagram showing the relationship between the optical path amount and the measurement value, with the horizontal axis representing the optical path amount from the mold measurement unit 9 to the measurement target and the vertical axis representing the measurement value actually acquired by the mold measurement unit 9. Ideally, the relationship between the optical path amount and the measurement value is a linear relationship as shown by the dashed line in Fig. 6(a), but in reality, the measurement value contains a nonlinear component (cyclic error) that changes periodically according to the optical path amount. As shown in Fig. 6(b), the cyclic error has a waveform that can be approximated by a sine wave depending on the amount of light path from the type measurement unit 9 to the measurement target. The amplitude of the cyclic error (waveform) can range from several tens of nm to more than 100 nm. The period of the cyclic error depends on the wavelength of the light (measurement light) from the type measurement unit 9, and is about several hundred nm.

[0056] On the other hand, the stage 110 is floated by several μm to several tens of μm from the reference surface 130A of the base plate 130 by an air guide (stage bottom driving mechanism 112), so that the position control of the stage 110 is air pressure control. Therefore, a position error of about several hundreds of nm occurs when the stage 110 floats, and an error equivalent to such a position error is included in the measurement value acquired by the mold measurement unit 9. As a result, depending on the height at which the stage 110 floats, waveform data 24a or 24b having different heights (positions in the Z direction) are obtained as the measurement value acquired by the mold measurement unit 9, as shown in FIG. 5(b). Furthermore, since the measurement value acquired by the mold measurement unit 9 includes a cyclic error as described above, a difference in waveform height occurs between the waveform data 24a and the waveform data 24b due to a phase difference. In such a case, since the waveform data 24a and 24b have asymmetric shapes and different waveform heights, an error (Δd5) occurs between the center of gravity 27a of the waveform data 24a and the center of gravity 27b of the waveform data 24b. If an error Δd5 occurs between the centers of gravity of the waveform data 24a and the waveform data 24b, it becomes an error when determining the amount of positional deviation in the planar direction of the mold M (S104). As a result, a positional deviation occurs when the imprint material 14 is placed on the substrate (S107) or when a pattern is formed on the substrate (S108). Therefore, even if a positional error occurs when the stage 110 is floated, it is necessary to prevent a difference in height between the waveform data (waveform data 24a and 24b) in order to prevent the error Δd5 from occurring.

[0057] Therefore, in this embodiment, a technique is provided for always keeping constant the optical path amount (distance) from the mold measurement unit 9 to the mold M (the mesa portion Me of the mold M) that is the measurement target when the mold measurement unit 9 measures the gap amount (S204) while driving the mold measurement unit 9 by the stage 110. To realize this technique, the processes of S202, S203, S206, and S207 are performed.

[0058] In S202, the mold measurement unit 9 measures the surface of the mold M, i.e., the mesa portion Me of the mold M, to obtain a measurement value. Specifically, the mold measurement unit 9 measures the gap amount in a state where the mold measurement unit 9 is disposed below the measurement start position of the measured line of the mesa portion Me of the mold M. Here, the mold measurement unit 9 measures the gap amount for at least one measured line (location) among the multiple measured lines of the mesa portion Me of the mold M. In addition, it is preferable that the at least one measured line measured by the mold measurement unit 9 is the first measured line (location) whose gap amount is measured by the mold measurement unit 9 in the measurement process (S102). This makes it possible to minimize the time required for the mold measurement unit 9 to measure the gap amount.

[0059] In S203, it is determined whether the measurement value acquired in S202 is within a predetermined tolerance range. If the measurement value acquired in S202 is within the predetermined tolerance range, the process proceeds to S204. On the other hand, if the measurement value acquired in S202 is not within the predetermined tolerance range, the process proceeds to S206. In this embodiment, if the period of the cyclic error is 400 nm, the tolerance is set to about 10 nm to 20 nm, and the tolerance range is set to 2 times the tolerance. The tolerance needs to be smaller than half the period of the cyclic error, but it is preferable to set it as small as possible in consideration of the drive reproducibility of the mold holding unit 4 and the measurement reproducibility of the mold measurement unit 9. In addition, when adjusting to prevent positional deviation from occurring when arranging the imprint material 14 on the substrate (S107) or when forming a pattern on the substrate (S108), the gap amount of the mold measurement unit 9 used in S102 is set to a predetermined value. The gap amount of the mold measurement unit 9 used in S102 is the distance between the mold measurement unit 9 and the mesa portion Me of the mold M after the stage 110 is driven so that the recessed portions 23a to 23d of the mesa portion Me of the mold M can be measured by the mold measurement unit 9.

[0060] In S206, the target position of the mold holding part 4 is reset (updated). Specifically, first, the difference between the measurement value acquired in S202 and a predetermined value is calculated. Then, the position obtained by adding the difference between the measurement value acquired in S202 and the predetermined value to the target position of the mold holding part 4 is set as the new target position of the mold holding part 4.

[0061] In S207, the mold holding part 4 is driven to the target position, i.e., the target position reset in S206. In other words, the position of the mold holding part 4 in the direction intersecting the reference surface 130A of the base plate 130, i.e., in the Z direction, is adjusted so that the mold holding part 4 is at the target position reset in S206.

[0062] 7(a) to 7(f), a procedure for making adjustments to prevent misalignment from occurring when placing the imprint material 14 on the substrate (S107) or when forming a pattern on the substrate (S108) will be described. This procedure is generally the same as the process flow shown in Fig. 2, but the predetermined value (Δg) used in S203 is set (determined) during adjustment, and the predetermined value (Δg) must be continuously used in the subsequent process flows.

[0063] 7(a), the mark on the stage reference plate 10 attached to the stage 110 is measured by the alignment measurement system 6. Note that the measurement of the mark on the stage reference plate 10 by the alignment measurement system 6 is performed after the origin of the stage 110 is adjusted using a photoswitch or the like. Here, the positional deviation of the mark measured by the alignment measurement system 6 is set to Δd1. By constantly adding the positional deviation Δd1 of the mark to the origin after the origin adjustment of the stage 110, it becomes possible to adjust the origin of the stage 110 based on the alignment measurement system 6.

[0064] In FIG. 7(b), as explained in S104 of FIG. 2, the amount of positional deviation of the mold M in the planar direction is determined. Here, in a state in which the origin adjustment of the stage 110 has been performed, the mold measurement unit 9 measures the positional deviation of the mold M held by the mold holding unit 4. The positional deviation of the mold M measured by the mold measurement unit 9 is set to Δd2. In addition, the gap amount (the distance between the mold measurement unit 9 and (the mesa portion Me of) the mold M) when the mold measurement unit 9 measures the positional deviation Δd2 of the mold M is set to Δg. The gap amount Δg needs to be determined as a predetermined value when performing S203 of FIG. 7.

[0065] For example, the gap amount Δg may be set within a distance range corresponding to a range in which the measurement value acquired by the mold measurement unit 9 is insensitive to the cyclic error, taking into consideration the period of the cyclic error. Specifically, as shown in FIG. 6(b), the gap amount Δg (a predetermined value) is set (confirmed) so that the optical path amount from the mold measurement unit 9 to the mold M (the mesa part Me) to be measured is the portion of the loops 32a to 32g of the sine wave approximating the cyclic error. This makes it difficult for a difference to occur in the height of the waveform data even if the distance (gap amount) from the mold measurement unit 9 to the mold M deviates (varies) from the predetermined value. Therefore, it is preferable to set the gap amount Δg, i.e., a predetermined value, so that the optical path amount is the portion of the loop of the sine wave when the cyclic error is approximated by the sine wave.

[0066] 7(c), as described in S106 of Fig. 2, a plurality of alignment marks provided on the substrate W are measured by the alignment measurement system 6 to determine the amount of misalignment in the planar direction of the substrate W. Here, in a state in which the origin adjustment of the stage 110 has been performed, the alignment measurement system 6 measures the misalignment of the substrate W held by the stage 110 (chuck 111). The misalignment of the substrate W measured by the alignment measurement system 6 is denoted as Δd3.

[0067] 7(d), as described in S107 of FIG. 2, the supply unit 7 places the imprint material 14 on the substrate (on the shot area of ​​the substrate W). Here, in a state where the origin adjustment of the stage 110 has been performed, the imprint material 14 needs to be placed on the substrate in consideration of the positional deviation Δd3 of the substrate W so that there is no deviation in the position of the imprint material 14 placed on the substrate W from the supply unit 7. In addition, in a state where the origin adjustment of the stage 110 has been performed, the imprint material 14 needs to be placed on the substrate in consideration of the positional deviation Δd2 of the mold M so that there is no deviation when the mold M is brought into contact with the imprint material 14 on the substrate. Therefore, in a state where the origin adjustment of the stage 110 has been performed, the imprint material 14 is placed on the substrate in consideration of the positional deviation Δd3 of the substrate W and the positional deviation Δd2 of the mold M.

[0068] 7(e), the mold M is brought into contact with the imprint material 14 on the substrate, the mold M and the substrate W are aligned, and light 17 is irradiated from the irradiation unit 2 to harden the imprint material 14. Here again, as described above, the positional misalignment Δd3 of the substrate W and the positional misalignment Δd2 of the mold M are taken into consideration.

[0069] In FIG. 7(f), after the mold M is separated from the hardened imprint material 14 on the substrate, the alignment measurement system 6 or an external measuring device (not shown) measures the positional deviation of the pattern of the imprint material 14 formed on the substrate. Here, the outer shape or base pattern of the substrate W is compared with the pattern of the imprint material 14 formed on the substrate, and the comparison result is obtained as the positional deviation Δd4. By considering the positional deviation Δd4 of the pattern of the imprint material 14 formed on the substrate in S107 and S108 of FIG. 2, the deviation of the pattern of the imprint material 14 formed on the substrate can be reduced. Then, when the amount of positional deviation of the mold M in the planar direction is determined in S102 and S104 of FIG. 2, the gap amount Δg can be adjusted to a predetermined value (within a tolerable range) to obtain the position of the mold M in the planar direction with high accuracy, which is advantageous for forming a pattern on the substrate.

[0070] As described above, in this embodiment, before performing the measurement process (S102), the position of the mold holding unit 4 in the Z direction is adjusted so that the gap amount measured by the mold measurement unit 9 falls within a range in which the measurement value is insensitive to cyclic error. Therefore, in the measurement process, when the mold measurement unit 9 measures multiple locations of each of the recessed portions 23a to 23d provided in the mesa portion Me of the mold M while driving the mold measurement unit 9 by the stage 110, it is possible to reduce fluctuations in the measurement value caused by cyclic error. This makes it possible to determine the position in the planar direction of the mold M held by the mold holding unit 4 with high accuracy, which is advantageous for forming a pattern of the imprint material 14 on the substrate while suppressing positional deviation.

[0071] In this embodiment, as shown in Fig. 4, a case has been described as an example in which both the mold holding unit 4 and the stage 110 are driven to the target position in S201. However, the waveform data 24 as the measurement value acquired by the mold measurement unit 9 may have an inclined waveform as shown in Fig. 8. This is because even if the stage 110 is levitated by the stage bottom driving mechanism 112 (air guide), it takes time for the state to reach an equilibrium state. Therefore, while the stage 110 is being driven in S204, the position 31 (height) of the stage 110 in the Z direction, i.e., the position (Z direction) of the mold measurement unit 9 provided on the stage 110, may vary.

[0072] In this way, when the position of the stage 110 in the Z direction fluctuates, it is preferable to perform S301 and S302 instead of S201, as shown in FIG. 9. In S301, the mold holding unit 4 is driven to the target position. In S302, the stage 110 is pre-driven and then driven to the target position. In this embodiment, pre-driving the stage 110 means driving the stage 110 (the mold measurement unit 9 provided thereon) in a direction (planar direction) along the reference surface 130A of the base plate 130 before adjusting the position of the mold holding unit 4 in the Z direction (S207). In addition, in pre-driving the stage 110, the stage 110 (the mold measurement unit 9) is driven with a stroke larger than the stroke for driving the stage 110 (the mold measurement unit 9) in the measurement process. As a result, in S204, the floating state of the stage 110 becomes balanced, and the waveform data as the measurement value acquired by the mold measurement unit 9 does not have an obliquely inclined waveform. The process of S301 and the process of S302 may be performed in parallel.

[0073] The pattern of the cured product formed using the imprint apparatus 1 in this embodiment is used permanently on at least a part of various articles, or temporarily when manufacturing various articles. The articles include electric circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of the electric circuit elements include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGA. Examples of the molds include molds for imprinting.

[0074] The pattern of the cured product may be used as it is as at least a part of the component of the above-mentioned article, or may be used temporarily as a resist mask, which is removed after etching or ion implantation is performed in a substrate processing step.

[0075] Next, a specific method for manufacturing the article will be described. As shown in Fig. 10(a), a substrate such as a silicon wafer with a workpiece such as an insulator formed on its surface is prepared, and then an imprint material is applied to the surface of the workpiece by an inkjet method or the like. Here, the state in which the imprint material in the form of multiple droplets is applied to the substrate is shown.

[0076] As shown in Fig. 10(b), the imprinting mold is placed with the side on which the concave and convex patterns are formed facing the imprinting material on the substrate. As shown in Fig. 10(c), the substrate on which the imprinting material has been applied is brought into contact with the mold, and pressure is applied. The imprinting material fills the gap between the mold and the workpiece. When light is irradiated through the mold in this state as hardening energy, the imprinting material hardens.

[0077] As shown in Fig. 10(d), when the imprint material is cured and then the mold and the substrate are separated, a pattern of the cured product of the imprint material is formed on the substrate. In this cured product pattern, the concave portions of the mold correspond to the convex portions of the cured product, and vice versa, i.e., the concave and convex patterns of the mold are transferred to the imprint material.

[0078] As shown in Fig. 10(e), when etching is performed using the pattern of the cured material as an etching-resistant mask, the portions of the surface of the workpiece where there is no cured material or where only a thin portion remains are removed, forming grooves. As shown in Fig. 10(f), when the pattern of the cured material is removed, an article having grooves formed on the surface of the workpiece can be obtained. Here, the pattern of the cured material is removed, but it may be used as an interlayer insulating film included in a semiconductor element, i.e., a component of an article, without being removed after processing.

[0079] The disclosure of the present specification includes the following imprint apparatus and method for manufacturing an article.

[0080] (Item 1) An imprinting apparatus for forming a pattern of an imprint material on a substrate using a mold, comprising: A mold holding unit that holds and drives the mold; a substrate holder that holds and drives the substrate; a measurement unit that measures a distance to a surface of the mold held by the mold holding unit and acquires a measurement value; a drive unit that drives the measurement unit in a direction along a reference plane that serves as a reference for driving the substrate holding unit; a control unit that performs a measurement process in which the measurement unit measures the distance for a plurality of points of a structure provided on the surface of the mold while driving the measurement unit with the drive unit, and determines a position of the mold in the direction from the measurement values ​​for the plurality of points; having The measurement value includes a cyclic error caused by a distance between the measurement unit and the mold, before performing the measurement process, the control unit adjusts a position of the mold holding unit in a direction intersecting the reference plane so that the distance measured by the measurement unit falls within a distance range corresponding to a range in which the measurement value is insensitive to the cyclic error. 1. An imprint apparatus comprising:

[0081] (Item 2) The mold includes a convex portion on the surface that protrudes from a peripheral portion, The structure is provided on the protrusion, The control unit determines a position of the convex portion in the direction as a position of the mold in the measurement process. 2. The imprint apparatus according to item 1,

[0082] (Item 3) 3. The imprint apparatus according to item 1 or 2, wherein the distance range corresponds to a range smaller than half the period of the cyclic error.

[0083] (Item 4) The imprinting apparatus described in any one of items 1 to 3, characterized in that the range in which the measurement value is insensitive to the cyclic error is an antinode portion of a sine wave when the cyclic error is approximated by a sine wave.

[0084] (Item 5) 2. The imprint apparatus according to claim 1, wherein the structure includes a concave recess formed by carving out the surface.

[0085] (Item 6) 6. The imprint apparatus according to item 5, wherein the recess has a depth of 20 nm or more and 200 nm or less.

[0086] (Item 7) The imprint apparatus described in any one of items 1 to 6, characterized in that before performing the measurement process, the control unit measures the distance for at least one of the multiple locations using the measurement unit, and adjusts the position of the mold holding unit in a direction intersecting the reference plane based on the measurement value for the at least one location so that the distance measured by the measurement unit falls within the distance range.

[0087] (Item 8) 8. The imprint apparatus according to item 7, wherein the at least one location is a first location where the distance is measured by the measurement unit in the measurement process.

[0088] (Item 9) The imprinting apparatus described in any one of items 1 to 8, characterized in that the control unit performs a pre-drive in which the drive unit drives the measurement unit in a direction along the reference surface before adjusting the position of the mold holding unit in a direction intersecting the reference surface.

[0089] (Item 10) The imprint apparatus of item 9, characterized in that, in the pre-driving, the control unit drives the measurement unit by the drive unit with a stroke that is larger than a stroke used to drive the measurement unit by the drive unit in the measurement process.

[0090] (Item 11) the measurement unit is provided on the substrate holding unit, The drive unit drives the substrate holding unit to drive the measurement unit. 11. The imprinting apparatus according to item 9 or 10,

[0091] (Item 12) 12. The imprint apparatus of any one of items 1 to 11, wherein the control unit performs the measurement process while keeping the distance between the measurement unit and the mold within the distance range.

[0092] (Item 13) The imprint apparatus described in any one of items 1 to 12, characterized in that the control unit performs a process of aligning the mold and the substrate based on the position of the mold obtained by the measurement process and transferring a pattern of the mold to the substrate.

[0093] (Item 14) forming a pattern on a substrate using the imprint apparatus according to any one of items 1 to 13; processing the substrate on which the pattern has been formed in the process; producing an article from the processed substrate; A method for producing an article, comprising the steps of:

[0094] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0095] 1: Imprinting device 4: Mold holding section 5: Control section 9: Mold measurement section 23a, 23b, 23c, 23d: Engraved section 110: Stage 120: Movable section 130: Surface plate 130A: Reference surface M: Mold Me: Mesa section W: Substrate

Claims

1. An imprinting apparatus for forming a pattern of an imprint material on a substrate using a mold, comprising: A mold holding unit that holds and drives the mold; a substrate holder that holds and drives the substrate; a measurement unit that measures a distance to a surface of the mold held by the mold holding unit and acquires a measurement value; a drive unit that drives the measurement unit in a direction along a reference plane that serves as a reference for driving the substrate holding unit; a control unit that performs a measurement process in which the measurement unit measures the distance for a plurality of points of a structure provided on the surface of the mold while driving the measurement unit with the drive unit, and determines a position of the mold in the direction from the measurement values ​​for the plurality of points; having The measurement value includes a cyclic error caused by a distance between the measurement unit and the mold, before performing the measurement process, the control unit adjusts a position of the mold holding unit in a direction intersecting the reference plane so that the distance measured by the measurement unit falls within a distance range corresponding to a range in which the measurement value is insensitive to the cyclic error.

1. An imprint apparatus comprising:

2. The mold includes a convex portion on the surface that protrudes from a peripheral portion, The structure is provided on the protrusion, The control unit determines a position of the convex portion in the direction as a position of the mold in the measurement process. The imprint apparatus according to claim 1 .

3. The imprint apparatus according to claim 1 , wherein the distance range corresponds to a range smaller than half the period of the cyclic error.

4. 2. The imprint apparatus according to claim 1, wherein the range in which the measurement value is insensitive to the cyclic error is an antinode of a sine wave when the cyclic error is approximated by a sine wave.

5. The imprint apparatus according to claim 1 , wherein the structure includes a concave recess formed by carving out the surface.

6. The imprint apparatus according to claim 5 , wherein the recess has a depth of 20 nm or more and 200 nm or less.

7. The imprint apparatus of claim 1, wherein the control unit measures the distance for at least one of the multiple locations using the measurement unit before performing the measurement process, and adjusts the position of the mold holding unit in a direction intersecting the reference plane based on the measurement value for the at least one location so that the distance measured by the measurement unit falls within the distance range.

8. The imprint apparatus according to claim 7 , wherein the at least one location is a first location where the distance is measured by the measurement unit in the measurement process.

9. The imprint apparatus according to claim 1, wherein the control unit performs a pre-driving operation to drive the measurement unit in a direction along the reference surface using the drive unit before adjusting the position of the mold holding unit in a direction intersecting the reference surface.

10. The imprint apparatus according to claim 9 , wherein, in the pre-driving, the control unit drives the measurement unit by the drive unit with a stroke that is larger than a stroke with which the drive unit drives the measurement unit in the measurement process.

11. the measurement unit is provided on the substrate holding unit, The drive unit drives the substrate holding unit to drive the measurement unit. The imprint apparatus according to claim 9 .

12. The imprint apparatus according to claim 1 , wherein the control unit performs the measurement process in a state in which the distance between the measurement unit and the mold falls within the distance range.

13. The imprint apparatus according to claim 1 , wherein the control unit performs a process of aligning the mold and the substrate based on the position of the mold obtained by the measurement process, and transferring a pattern of the mold to the substrate.

14. forming a pattern on a substrate using the imprint apparatus according to any one of claims 1 to 13; processing the substrate on which the pattern has been formed in the process; producing an article from the processed substrate; A method for producing an article, comprising the steps of:

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