Adjustment method, imprinting method, article manufacturing method, and imprinting device

Abstract

This adjustment method is for an imprinting device including: a detection unit that detects a relative position between a mark of a mold held by a mold holding unit and a mark of a substrate held by a stage; and a measurement unit that is mounted on the stage and measures a surface height distribution of the mold held by the mold holding unit. The adjustment method determines an offset of the measurement unit on the basis of: a position of a member estimated on the basis of a result of detecting, by the detection unit, the relative position between a mark of the member held by the mold holding unit and the mark of the stage; and a position of the member estimated on the basis of a result of measuring, by the measurement unit, a surface height distribution of the member held by the mold holding unit.

Description

Adjustment method, imprint method, article manufacturing method, and imprint apparatus

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

[0002] As demand for miniaturization of semiconductor devices, MEMS, and the like continues to grow, attention is being drawn to microfabrication techniques, in addition to conventional photolithography techniques. These techniques involve molding an uncured imprint material on a substrate using a mold to form a pattern of the imprint material on the substrate. This technique, also known as imprinting, can be used to form microstructures on a substrate on the order of a few nanometers. For example, one imprinting technique is the photocuring method. In an imprinting apparatus employing this photocuring method, a mold is brought into contact with an imprint material (photocurable resin) supplied onto a substrate (wafer), the imprint material is cured, and the mold is then separated from the cured imprint material. This allows a pattern composed of the cured imprint material to be formed on the substrate.

[0003] A mold used in an imprinting apparatus has a protruding portion called a mesa portion, and a pattern is formed on the mesa portion. In the imprinting apparatus, the surface height distribution of the mold is measured to accurately form a pattern of the imprint material on a substrate, and the position, tilt, and rotation of the mesa portion of the mold are controlled based on the measurement results. Patent Document 1 discloses an imprinting apparatus that includes a measurement unit on a substrate stage that measures the surface height distribution of the mold. The measurement unit can measure the surface height distribution of the mold by sequentially detecting the distance to the mold (i.e., the surface height of the mold) while moving in a planar direction in accordance with the movement of the substrate stage.

[0004] Patent No. 6029268

[0005] In imprinting apparatuses, there are cases where the measurement unit that measures the surface height distribution of the mold is offset from a predetermined position on the substrate stage, or an optical member is incorporated into the measurement unit offset from a predetermined position, etc. In such cases, it becomes difficult to accurately control the position, tilt, and rotation of the mesa portion of the mold based on the measurement results of the measurement unit, and therefore it is desirable to accurately obtain the offset of the measurement unit.

[0006] Patent Document 1 describes a method for obtaining the offset of a measurement unit using an alignment scope that detects a mark on a mold (mesa portion) as a reference. In this method, the position of the mesa portion, determined by detecting the mark on the mesa portion with the alignment scope, is used as a reference, and the deviation of the position of the mesa portion, determined by measuring the surface height distribution of the mold with the measurement unit, from the reference is obtained as the offset of the measurement unit. However, in imprint apparatuses, the alignment scope and the measurement unit are generally driven by separate drive systems, and the positional relationship between them is not guaranteed. Therefore, the method described in Patent Document 1 was insufficient to obtain the offset of the measurement unit with high accuracy.

[0007] Therefore, an object of the present invention is to provide an advantageous technique for accurately obtaining the offset of a measurement unit that measures the surface height distribution of a mold.

[0008] In order to achieve the above-mentioned object, one aspect of the present invention provides an adjustment method for an imprinting apparatus that includes a detection unit that detects the relative position of a mark on a mold held by a mold holding unit and a mark on a substrate held by a stage, and a measurement unit that is mounted on the stage and measures the surface height distribution of the mold held by the mold holding unit, and that forms a pattern of imprint material on the substrate using the mold, the adjustment method comprising: a first estimation step of detecting the relative position of the mark on a member held by the mold holding unit and a mark on the stage, and estimating the position of the member in a coordinate system for controlling the position of the stage based on the detection result; a second estimation step of measuring the surface height distribution of the member held by the mold holding unit with the measurement unit, and estimating the position of the member in the coordinate system based on the measurement result; and a determination step of determining an offset of the measurement unit based on the position of the member estimated in the first estimation step and the position of the member estimated in the second estimation step.

[0009] According to the present invention, for example, it is possible to provide an advantageous technique for accurately obtaining the offset of a measurement unit that measures the surface height distribution of a mold.

[0010] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0011] The accompanying drawings are included in and constitute a part of the specification, illustrate embodiments of the present invention, and are used to explain the principles of the present invention together with the description thereof: A schematic diagram showing an example of the configuration of an imprinting apparatus according to an embodiment of the present invention; A flowchart showing an imprinting process according to an embodiment of the present invention; A diagram for explaining the offset of a second measurement unit; A flowchart showing an adjustment process according to an embodiment of the present invention; A diagram showing an example of the configuration of an adjustment member (mold) and measurement of surface height distribution; A diagram for explaining an article manufacturing method;

[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0013] Unless otherwise specified, in this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system, with the XY plane being a plane parallel to the surface of the substrate. The directions parallel to the X, Y, and Z axes 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 referred to as θX, θY, and θZ, respectively. Control or drive about the X, Y, and Z axes refers to control or drive in directions parallel to the X axis, Y axis, and Z axis, respectively. Furthermore, control or drive about the θX, θY, and θZ axes refers to control or drive in directions parallel to the X axis, Y axis, and Z axis, respectively. Furthermore, position is information that can be determined based on coordinates of the X, Y, and Z axes, and orientation is information that can be determined by values ​​of the θX, θY, and θZ axes.

[0014] An embodiment of the present invention will be described below. An imprinting apparatus is a lithography apparatus that uses a mold to form an imprinting material (composition) on a substrate. It can be used in lithography processes, which are used in the manufacture of devices such as semiconductor devices and magnetic storage media. The imprinting apparatus brings uncured imprinting material supplied to a substrate into contact with the mold and applies curing energy to the imprinting material, thereby forming a cured pattern on the substrate, to which the concave and convex patterns of the mold have been transferred. This process, called an imprinting process, is performed on a pattern formation area of ​​the substrate. For example, an imprinting apparatus is used in the manufacture of devices such as semiconductor devices. The imprinting apparatus uses a mold to form an uncured imprinting material on a wafer (substrate), which is a substrate to be processed, thereby forming a pattern of the imprinting material on the wafer. In addition to the above, the imprinting apparatus can also perform a process of forming a pattern on the convex portions of a blank mold in order to manufacture multiple replica molds having identical pattern portions.

[0015] [Configuration of Imprint Apparatus] FIG. 1 is a schematic diagram showing an example of the configuration of an imprint apparatus 100 according to the present embodiment. The imprint apparatus 100 according to the present embodiment can be used to fabricate replica molds and / or manufacture semiconductor devices and the like. When the imprint apparatus 100 is used to fabricate replica molds, a master mold on which a pattern is formed is used as the mold M, and a blank mold before the pattern is formed is used as the substrate W. In this case, a portion (protruding portion) of the blank mold serving as the substrate W becomes a pattern formation region where the imprint process is performed. On the other hand, when the imprint apparatus 100 is used to manufacture semiconductor devices and the like, a replica mold on which a pattern is formed is used as the mold M, and a semiconductor wafer (e.g., a silicon wafer) is used as the substrate W. In this case, each of a plurality of shot areas on the semiconductor wafer serving as the substrate W becomes a pattern formation region where the imprint process is performed. The following description will exemplify a case in which the imprint apparatus 100 is used to fabricate replica molds; however, the apparatus configuration and process contents are similar when the imprint apparatus 100 is used to manufacture semiconductor devices and the like. In the following, an example will be described in which the imprint apparatus 100 employs a photo-curing method in which the imprint material is cured by irradiating it with light.

[0016] The mold M typically has a rectangular outer periphery and is made of a material that can transmit light 11 (e.g., ultraviolet light), such as quartz glass. A mesa portion Me configured in a convex shape with a step, for example, is provided in a partial region of the surface of the mold M that faces the substrate W. A concave-convex pattern to be transferred to the imprint material on the substrate W is formed on the surface of the mesa portion Me facing the substrate W. In other words, the mesa portion Me may be understood as a pattern portion on which the concave-convex pattern to be transferred to the imprint material on the substrate W is formed. In addition, an alignment mark 23 that can be detected (observed) by a second detection unit 72 (alignment scope) described later is provided on the surface of the mesa portion Me facing the substrate W.

[0017] The substrate W may be made of glass, ceramics, metal, semiconductor, resin, or the like, and may have a member made of a material different from that of the substrate formed on its surface as necessary. Specifically, when the imprint apparatus 100 is used to produce a replica mold, a blank mold made of quartz glass may be used as the substrate W. On the other hand, when the imprint apparatus 100 is used to manufacture semiconductor devices or the like, a silicon wafer, a compound semiconductor wafer, or a quartz glass plate may be used as the substrate W.

[0018] The imprint apparatus 100 may include, for example, a light irradiation unit 10, a mold holding unit 20 that holds the mold M, a substrate holding unit 30 that holds the substrate W, drive mechanisms (beam member 40, X drive unit 50, Y drive unit 60) that drive the substrate holding unit 30, and a controller CNT. The imprint apparatus 100 may also include a first detection unit 71 that detects the position of an alignment mark on the substrate W, and a second detection unit 72 that detects the relative position between the alignment mark 23 on the mold M and the alignment mark on the substrate W. The imprint apparatus 100 may also include a first measurement unit 81 that measures the surface height distribution of the substrate W, and a second measurement unit 82 that measures the surface height distribution of the mold M. Although not shown in FIG. 1 , the imprint apparatus 100 may also include a mold transport mechanism that transports the mold M and a substrate transport mechanism that transports the substrate W.

[0019] During the imprint process, the light irradiation unit 10 irradiates light 11 (e.g., ultraviolet light) onto the imprint material on the substrate W while the mold M is in contact with the imprint material, thereby curing the imprint material. The light irradiation unit 10 may include, for example, a light source and an optical element. The optical element adjusts the light emitted from the light source to light appropriate for irradiating the imprint material.

[0020] The mold holding unit 20 (imprint head) is configured to hold the mold M and move in the Z direction. Specifically, the mold holding unit 20 may include a mold chuck 21 that holds the mold M by vacuum suction or the like, and a mold driving mechanism 22 that drives the mold M by driving the mold chuck 21. The mold holding unit 20 drives the mold M in the Z direction to perform a contact operation that brings the mold M into contact with the imprint material on the substrate W, and a release operation that separates the mold M from the hardened imprint material on the substrate W. However, the mold holding unit 20 may be configured to have a position adjustment function for adjusting the position of the mold M not only in the Z direction, but also in the X direction, Y direction, and rotational directions around each axis (θX, θY, and θZ directions), as well as a tilt function for correcting the inclination of the mold M. Note that the contact operation and release operation in the imprint process may be performed by driving the mold M in the Z direction by the mold holding unit 20, or may be performed by driving the substrate W in the Z direction by the substrate holding unit 30, which will be described later. Alternatively, the imprinting operation and the mold releasing operation may be performed by driving the mold M and the substrate W relatively in the Z direction by both the mold holding part 20 and the substrate holding part 30 .

[0021] The substrate holding unit 30 is configured to be movable in the X and Y directions while holding the substrate W. The substrate holding unit 30 may include a substrate chuck 31 that holds the substrate W by vacuum suction or the like, and a stage 32 that supports the substrate chuck 31 and moves in the X and Y directions on the surface plate 1. The substrate holding unit 30 is driven in the X and Y directions by a drive mechanism including a beam member 40, an X drive unit 50, and a Y drive unit 60 to align the mold M with the substrate W. However, the substrate holding unit 30 may be configured to have a position adjustment function for adjusting the position of the substrate W not only in the X and Y directions but also in the Z direction and rotational directions around each axis (θX, θY, and θZ directions), or a tilt function for correcting the inclination of the substrate W.

[0022] A bottom drive mechanism 33 is provided on the bottom (lower surface) of the stage 32 for positioning the stage 32 in the Z direction. In the imprinting apparatus 100, it is preferable to drive the stage 32 in the X and Y directions with a large stroke at high speed and high precision while reducing friction and wear between the stage 32 and the base plate 1. Therefore, the bottom drive mechanism 33 causes the stage 32 to float several micrometers to several tens of micrometers above the reference surface (top surface) of the base plate 1. For example, the bottom drive mechanism 33 has an air guide, and can position the stage 32 in the Z direction by ejecting gas from the air guide toward the reference surface (top surface) of the base plate 1 to form a gap between the stage 32 and the base plate 1. To stabilize the position of the stage 32 in the Z direction, the bottom drive mechanism 33 may have a suction mechanism that attracts the stage 32 and the base plate 1 to each other, such as a cylinder mechanism that uses air, magnets, or fluid pressure.

[0023] The beam member 40 is a member extending in the X direction to guide the movement of the stage 32 in the X direction and is arranged to pass through an opening provided in the stage 32. The beam member 40 may include, for example, a guide portion 41 that guides the movement of the stage 32 in the X direction and a support portion 42 that supports the guide portion 41 at both ends of the guide portion 41. A mover 62 of a Y drive unit 60 (described later) is fixed to the support portion 42, and air guides 43 and 44 are provided on the support portion 42. The air guide 43 jets gas toward the base 1 to form a gap between the support portion 42 and the base 1, thereby positioning the beam member 40 (support portion 42) in the Z direction. The air guide 44 jets gas toward a fixed member 2 fixed to the base 1 to form a gap between the support portion 42 and the fixed member 2, thereby positioning the beam member 40 (support portion 42) in the X direction. The fixed member 2 extends in the Y direction above the base 1.

[0024] The X driving unit 50 is a mechanism that drives the stage 32 in the X direction along the beam member 40, thereby driving the substrate holder 30 and the substrate W in the X direction. In the present embodiment, the X driving unit 50 can be configured by a linear motor having a stator 51 and a mover 52. The stator 51 includes a plurality of coils arranged along the X direction, and is provided on the guide portion 41 of the beam member 40. The mover 52 includes a permanent magnet, and is provided on the stage 32 (specifically, on the inner surface of the opening through which the guide portion 41 passes).

[0025] Y driving unit 60 is a mechanism that drives beam member 40 in the Y direction, thereby driving substrate holder 30 and substrate W in the Y direction. In the present embodiment, Y driving unit 60 can be configured by a linear motor having a stator 61 and a mover 62. Stator 61 has a plurality of coils arranged along the Y direction. Mover 62 includes a permanent magnet and is fixed to support portion 42 of beam member 40.

[0026] The position of the substrate holding unit 30 (stage 32) can be measured by a position measurement unit 34. The position measurement unit 34 measures the position of the stage 32 in a coordinate system for controlling the position of the stage 32 (hereinafter, sometimes referred to as a stage coordinate system). In the present embodiment, the position measurement unit 34 can be configured, for example, by a laser interferometer, but may also be configured by an encoder. This allows the control unit CNT to control the position of the stage 32 in the stage coordinate system based on the measurement results of the position measurement unit 34. Note that the stage coordinate system may be understood as a reference coordinate system that serves as a reference for controlling the position of the stage 32, or a measurement coordinate system for measuring the position of the stage 32.

[0027] Furthermore, a reference plate 35 is mounted on the stage 32 of the substrate holder 30. The reference plate 35 has an alignment mark 35a that is detected by a first detector 71 and a second detector 72, which will be described later. The alignment mark 35a may be provided so as to be shared by the first detector 71 and the second detector 72, or may be provided so as to be used individually by the first detector 71 and the second detector 72.

[0028] The first detection unit 71 is an alignment detection system (alignment scope) that detects the position of an alignment mark on the substrate W held by the substrate holding unit 30 (stage 32). The first detection unit 71 is sometimes called a substrate alignment detection system (substrate alignment scope). Based on the position of the alignment mark on the substrate W detected by this first detection unit 71, the control unit CNT can identify the position of the substrate W (pattern formation region).

[0029] The second detection unit 72 is an alignment detection system (alignment scope) that detects the relative position between the alignment mark 23 of the mold M held by the mold holding unit 20 and the alignment mark of the substrate W (pattern formation region) held by the substrate holding unit 30. The second detection unit 72 is sometimes called a mold alignment detection system (mold alignment scope). Based on the relative positions of the alignment mark 23 of the mold M and the alignment mark of the substrate W detected by this second detection unit 72, the controller CNT can control the alignment of the mold M (mesa portion Me) and the substrate W (pattern formation region). Here, the imprint apparatus 100 may be provided with multiple second detection units 72. In this case, it is possible to simultaneously detect pairs of the alignment mark 23 of the mold W and the alignment mark of the substrate W at multiple locations. Note that, hereinafter, the alignment mark may be simply referred to as a mark.

[0030] The first measurement unit 81 measures the surface height distribution of the substrate W held by the substrate holding unit 30. Specifically, the first measurement unit 81 may include a sensor that detects the distance to the surface of the substrate W in the Z direction (i.e., the surface height of the substrate W). The first measurement unit 81 can measure the surface height distribution of the substrate W by sequentially detecting the surface height of the substrate W while the substrate W is being moved in the X and Y directions by the substrate holding unit 30 (stage 32) below the first measurement unit 81.

[0031] The second measurement unit 82 is mounted on the stage 32 of the substrate holding unit 30 and measures the surface height distribution of the mold M held by the mold holding unit 20. Specifically, the second measurement unit 82 may include a sensor that detects the distance to the surface of the mold M in the Z direction (i.e., the surface height of the mold M). The second measurement unit 82 can measure the surface height distribution of the mold M by sequentially detecting the surface height of the mold M while moving below the mold M in conjunction with the movement of the substrate holding unit 30 (stage 32).

[0032] Here, the second measurement unit 82 may have a configuration including, for example, a measurement light source (e.g., a laser irradiation unit), an imaging element (sensor), and an analysis mechanism. In the second measurement unit 82 configured as described above, light (laser) emitted from the measurement light source toward the mold M is reflected by the surface of the mold M and returns to the second measurement unit 82. This returned light is observed (detected) by an imaging element such as a CCD, and the analysis mechanism calculates the distance to the mold M (hereinafter, sometimes referred to as the gap amount) based on the observation results. Methods for detecting the gap amount in the second measurement unit 82 include, for example, a method of detecting the gap amount based on the position of the returned light when light is incident obliquely with respect to the measurement direction, and a method of detecting the gap amount based on interference fringes between the returned light and the reference light. In the method of detecting the gap amount based on interference fringes, the beam spot of the reference light can have various shapes, such as a circular or elliptical shape, and its diameter can vary from 10 μm to 1000 μm. The average of the detected values ​​within the range of the beam spot diameter is the gap amount.

[0033] The supply unit 90 (dispenser) supplies the imprint material 91 as multiple droplets onto the substrate W. The supply unit 90 may be understood as a liquid ejection head that ejects (sprays) the imprint material 91 as multiple droplets toward the substrate W. For example, the supply unit 90 ejects the imprint material 91 as multiple droplets while the substrate W is moved in the X and Y directions relative to the supply unit 90 by the substrate holding unit 30 (stage 32) below the supply unit 90. This allows the imprint material 91 to be supplied as multiple droplets onto the substrate W (pattern formation region).

[0034] The imprint material 91 supplied onto the substrate W by the supply unit 90 is a curable composition (sometimes referred to as an uncured resin) that cures when curing energy is applied. Examples of the curing energy include electromagnetic waves, heat, and the like. Examples of the electromagnetic waves include light, such as infrared light, visible light, and ultraviolet light, having a wavelength selected from the range of 10 nm to 1 mm. The curable composition is a composition that cures when irradiated with light or when heated. Among these, a photocurable composition that cures when exposed to light contains at least a polymerizable compound and a photopolymerization initiator and may optionally contain a non-polymerizable compound or a solvent. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, and a polymer component. The imprint material 91 is applied to the substrate in the form of a film using a spin coater or a slit coater. Alternatively, the imprint material 91 may be applied to the substrate in the form of droplets, or in the form of islands or a film formed by connecting multiple droplets, using a liquid jetting head. The viscosity of the imprint material 91 (at 25° C.) is, for example, not less than 1 mPa·s and not more than 100 mPa·s.

[0035] The control unit CNT is configured by, for example, a computer (information processing device) having a processor such as a CPU (Central Processing Unit) and a storage unit such as a memory. The control unit CNT controls the operations of each unit of the imprint apparatus 100 and acquires values ​​obtained from various sensors (detection units 71-72, measurement units 81-82), thereby controlling the imprint process on the substrate W.

[0036] [Imprint Processing] Next, a description will be given of the imprint processing executed by the above-described imprint apparatus 100. Fig. 2 is a flowchart showing the imprint processing of this embodiment. The imprint processing shown in the flowchart of Fig. 2 can be executed by the control unit CNT comprehensively controlling each unit of the imprint apparatus 100.

[0037] In step S101, the control unit CNT causes a mold transport mechanism (not shown) to carry the mold M into the mold holding unit 20, and causes the mold holding unit 20 (mold chuck 21) to hold the mold M.

[0038] In step S102, the control unit CNT calculates the amount of positional deviation (XY directions, θZ direction, and magnification component) of the mesa portion Me of the mold M relative to the substrate holding unit 30 (stage 32). The amount of positional deviation of the mesa portion Me relative to the substrate holding unit 30 may be understood as the position of the mesa portion Me in the stage coordinate system.

[0039] Specifically, first, the control unit CNT moves the substrate holding unit 30 to retract the reference plate 35 out of the detection field of the second detection unit 72. The control unit CNT then moves the mold M using the mold holding unit 20 so that the mark 23 of the mesa portion Me of the mold M is positioned at the height of the focus plane of the second detection unit 72, and in this state, causes the second detection unit 72 to detect the position of the mark 23 of the mesa portion Me. Next, the control unit CNT then moves the mold M in the Z direction using the mold holding unit 20 so that the mark 23 of the mesa portion Me is retracted from the focus plane of the second detection unit 72. The control unit CNT then moves the substrate holding unit 30 so that the top surface of the reference plate 35 is positioned at the height of the focus plane of the second detection unit 72 and the mark 35 a of the reference plate 35 is positioned within the detection field of the second detection unit 72. In this state, the control unit CNT causes the second detection unit 72 to detect the position of the mark 35 a of the reference plate 35.

[0040] This allows the control unit CNT to determine the amount of misalignment of the mesa unit Me with respect to the substrate holding unit 30 (stage 32) based on the position of the mark on the mesa unit Me detected by the second detection unit 72 and the position of the mark 35a on the reference plate 35. Furthermore, the control unit CNT can determine the amount of misalignment of the mesa unit Me with respect to the substrate holding unit 30 not only in the XY directions but also in the θZ direction and the magnification component by causing the second detection unit 72 to detect the positions of two or more marks 23 on the mesa unit Me. The amount of misalignment can be calculated using the least squares method or the like.

[0041] In step S103, the control unit CNT measures the surface height distribution of the mold M using the second measurement unit 82. Specifically, the control unit CNT moves the substrate holding unit 30 (stage 32) in the X and Y directions to move the second measurement unit 82 in the X and Y directions relative to the mold M, while causing the second measurement unit 82 to detect the distance to the surface of the mold M (the surface height of the mold M). This allows the second measurement unit 82 to measure the surface height distribution of the mold M. Furthermore, the control unit CNT can obtain the position, height, inclination, shape, etc. of the mesa portion Me of the mold M based on the surface height distribution of the mold M measured by the second measurement unit 82.

[0042] Here, detection target locations for detecting the surface height by the second measurement unit 82 may be set in advance on the surface of the mold M. For example, if the second measurement unit 82 is made to detect the surface height of a portion where a concave portion of the uneven pattern is provided, a detection error may occur. Therefore, multiple detection target locations are set in portions where detection errors are unlikely to occur. The control unit CNT causes the second measurement unit 82 to detect the surface height for each of the multiple detection target locations on the surface of the mold M while stepping the substrate holding unit 30 (stage 32). This allows the second measurement unit 82 to measure the surface height distribution of the mold M based on the surface height detected at each of the multiple detection target locations.

[0043] In step S104, the controller CNT causes a substrate transport mechanism (not shown) to carry the substrate W into the substrate holding part 30, and causes the substrate holding part 30 (substrate chuck 31) to hold the substrate W.

[0044] In step S105, the control unit CNT determines the amount of positional deviation (XY directions, θZ direction, and magnification component) of the substrate W relative to the substrate holding unit 30. The amount of positional deviation of the substrate W relative to the substrate holding unit 30 may be understood as the position of the substrate W in a stage coordinate system. Specifically, the control unit CNT causes the first detection unit 71 to detect the position of each of the multiple marks on the substrate W while moving the substrate W below the first detection unit 71 using the substrate holding unit 30 (stage 32). The control unit CNT also causes the first detection unit 71 to detect the position of the mark 35 a on the reference plate 35. This allows the control unit CNT to determine the amount of positional deviation (XY directions, θZ direction, and magnification component) of the substrate W relative to the substrate holding unit 30, based on the positions of each mark on the substrate W detected by the first detection unit 71 and the position of the mark 35 a on the reference plate 35.

[0045] In step S106, the control unit CNT measures the surface height distribution of the substrate W using the first measurement unit 81. Specifically, the control unit CNT moves the substrate W in the X and Y directions relative to the first measurement unit 81 by moving the substrate holding unit 30 (stage 32) in the X and Y directions, while causing the first measurement unit 81 to detect the distance to the surface of the substrate W (the surface height of the substrate W). This allows the first measurement unit 81 to measure the surface height distribution of the substrate W. Furthermore, the control unit CNT can obtain the position, height, inclination, shape, etc. of the substrate W based on the surface height distribution of the substrate W measured by the first measurement unit 81.

[0046] In step S107, the control unit CNT calculates the relative position (XY directions, θZ direction, and magnification component) between the mold M (mesa portion Me) and the substrate W. Specifically, the control unit CNT calculates the relative position between the mold M (mesa portion Me) and the substrate W based on the positional deviation amount of the mesa portion Me obtained in step S102 and the positional deviation amount of the substrate W obtained in step S105. The positional deviation amount of the mesa portion Me obtained in step S102 and the positional deviation amount of the substrate W obtained in step S105 are determined using the mark 35a of the reference plate 35 in the substrate holding unit 30 (i.e., the stage coordinate system) as a common reference. Therefore, the control unit CNT can calculate and control the relative position between the mesa portion Me and the substrate W based on the positional deviation amount of the mesa portion Me and the positional deviation amount of the substrate W. Furthermore, the control unit CNT calculates the relative position between the mold M (mesa portion Me) and the substrate W, based on the surface height distribution of the mold M obtained in step S103 and the surface height distribution of the substrate W obtained in step S106. The control unit CNT may adjust the relative position between the mold M and the substrate W, based on the surface height distribution of the mold M and the surface height distribution of the substrate W, so that the relative position, height, inclination, and shape of the mold M (mesa portion Me) and the substrate W become desired.

[0047] In step S108, the control unit CNT supplies the imprint material 91 onto the substrate W (pattern formation region) (supply step). For example, the control unit CNT causes the supply unit 90 to eject the imprint material as multiple droplets while moving the substrate W in the X and Y directions using the substrate holding unit 30 below the supply unit 90. At this time, the control unit CNT controls the movement of the substrate W based on the relative positions of the mold M and the substrate W calculated in step S107. This allows the imprint material to be supplied onto the substrate W as multiple droplets.

[0048] In step S109, the control unit CNT forms a pattern of the mesa portion Me of the mold M in the imprint material on the substrate W (pattern formation process). Specifically, the control unit CNT positions the substrate W below the mold W using the substrate holding unit 30, and then aligns the mold M (mesa portion Me) with the substrate W (pattern formation region) while detecting the relative positions of the marks 23 on the mold M and the marks on the substrate W using the second detection unit 72. The control unit CNT then moves the mold W in the −Z direction using the mold holding unit 20 to bring the mold W into contact with the imprint material on the substrate W, and in this state, irradiates the imprint material 91 with light using the light irradiation unit 10 to harden the imprint material. After hardening the imprint material, the control unit CNT separates the mold W from the hardened imprint material 91 on the substrate W by moving the mold W in the +Z direction using the mold holding unit 20. As a result, a cured product of the imprint material 91 onto which the pattern of the mesa portion Me of the mold M has been transferred can be formed on the substrate W.

[0049] Here, in step S109, the control unit CNT may adjust the relative height and inclination between the mold M (mesa portion Me) and the substrate W, based on the relative height and inclination between the mold M (mesa portion Me) and the substrate W calculated in step S107. The adjustment of the relative height and inclination between the mold M (mesa portion Me) and the substrate W can be performed by the mold holding unit 20 and / or the substrate holding unit 30. Furthermore, the control unit CNT may correct the shape of the mold M (magnification correction) using a mold magnification correction mechanism (not shown) provided in the mold holding unit 20, based on the relative shapes between the mold M (mesa portion Me) and the substrate W calculated in step S107.

[0050] In step S110, the control unit CNT uses a substrate transport mechanism (not shown) to transport the substrate W out of the substrate holding unit 30. Next, in step S111, the control unit CNT determines whether or not there is a substrate W (next substrate W) to be subjected to the next imprint process. If there is a next substrate W, the process proceeds to step S104, and the control unit CNT executes steps S104 to S110 on the next substrate W. On the other hand, if there is no next substrate W, the process proceeds to step S112, and the control unit CNT uses a mold transport mechanism (not shown) to transport the mold M out of the mold holding unit 20.

[0051] [Offset of Second Measurement Unit] In the imprint apparatus 100, an offset of the second measurement unit 82 may occur. The offset of the second measurement unit 82 may occur when the second measurement unit 82 is mounted offset from a predetermined position on the stage 32 (mounting error) and / or when an optical member is assembled in the second measurement unit 82 offset from a predetermined position (optical axis misalignment). When such an offset of the second measurement unit 82 occurs, a measurement error corresponding to the offset occurs in the measurement results of the second measurement unit 82, which may make it difficult to accurately measure the surface height distribution of the mold M by the second measurement unit 82 in step S103 described above. In other words, it may be difficult to accurately form a pattern of the imprint material on the substrate.

[0052] Therefore, in this embodiment, an adjustment process of the imprint apparatus 100 is performed. The adjustment process of the imprint apparatus 100 can include a process of determining an offset of the second measurement unit 82. The adjustment process may be understood to further include a process of reflecting the offset in the measurement of the surface height distribution of the mold M by the second measurement unit 82 (step S103). The offset may be reflected by correcting the measurement results of the second measurement unit 82 with the offset, or by correcting the movement of the stage 32 with the offset during the measurement of the surface height distribution of the mold M by the second measurement unit 82. For example, the control unit CNT can control the movement of the stage 32 based on the offset of the second measurement unit 82 so as to reduce the measurement error of the second measurement unit 82.

[0053] FIG. 3 is a diagram illustrating the offset of the second measurement unit 82. FIG. 4 shows the stage 32 of the substrate holding unit 30, the reference plate 35, and the second measurement unit 82. When the second measurement unit 82 measures the surface height distribution of the mold M, a value obtained by adding up various errors, such as the mounting error and optical axis misalignment, may result in a positional deviation of the second measurement unit 82 in the X and Y directions. Such a positional deviation of the second measurement unit 82 is expressed as an error Err between the ideal position P2 of the second measurement unit 82 on the stage 32 and the mounting position P3, and this error Err is the offset of the second measurement unit 82. Here, the error Err may be understood as the error between the ideal position P2 of the second measurement unit 82 and the mounting position P3, based on the position P1 of the reference plate 35. The ideal position P2 refers to the position where the second measurement unit 82 should be located on the stage 32, i.e., based on the position P1 of the reference plate 35. The mounting position P3 is the position on the stage 32 where the second measurement unit 82 is actually mounted, using the position P1 of the reference plate 35 as a reference.

[0054] The adjustment process (adjustment method) of the imprint apparatus 100 in this embodiment will be described below. Fig. 4 is a flowchart showing the adjustment process of the imprint apparatus 100 in this embodiment. The adjustment process shown in the flowchart in Fig. 4 can be executed by the control unit CNT comprehensively controlling each part of the imprint apparatus 100. The adjustment process can be executed before the imprint process is executed, but may also be executed periodically.

[0055] Here, the adjustment member held by the mold holding unit 20 for performing the adjustment process is not limited to the mold M applied to the imprint process. The adjustment member can be a member that can be held by the mold holding unit 20 and is configured to have a characteristic portion formed by a step and an alignment mark. The characteristic portion may be a portion corresponding to the mesa portion Me of the mold M, or may have a shape that imitates the mesa portion Me. Furthermore, the positional relationship between the characteristic portion and the alignment mark in the adjustment member is known information (e.g., design information) and is obtained in advance. Note that, below, an example will be described in which the mold M applied to the imprint process is used as the adjustment member.

[0056] In step S201, the control unit CNT causes a mold transport mechanism (not shown) to carry the mold M into the mold holding unit 20, and causes the mold holding unit 20 (mold chuck 21) to hold the mold M.

[0057] In step S202, the control unit CNT moves the stage 32 of the substrate holding unit 30 so that the reference plate 35 is positioned below the mold M held by the mold holding unit 20. Then, the control unit CNT causes the second detection unit 72 to detect the relative position between the mark 23 of the mold M held by the mold holding unit 20 and the mark 35 a of the reference plate 35.

[0058] In step S203, the control unit CNT estimates the position of the mold M in the stage coordinate system based on the detection result in step S202. For example, the control unit CNT estimates the position of the mesa portion Me (feature portion) of the mold M in the stage coordinate system based on the relative positions of the mark 23 of the mold M and the mark 35a of the reference plate 35 detected by the second detection unit 72 in step S202. Here, the positional relationship between the mark 23 of the mold M and the mesa portion Me is guaranteed, and this information has been acquired in advance by the control unit CNT. In addition, the position of the reference plate 35 (mark 35a) relative to the stage 32 is also guaranteed, and this information has been acquired in advance by the control unit CNT. As a result, the control unit CNT can estimate the position of the mesa portion Me (feature portion) of the mold M in the stage coordinate system from the relative positions of the mark 23 of the mold M and the mark 35a of the reference plate 35 detected by the second detection unit 72 based on this information.

[0059] In step S204, the control unit CNT measures the surface height distribution of the mold M using the second measurement unit 82. Specifically, the control unit CNT moves the substrate holding unit 30 (stage 32) in the X and Y directions to move the second measurement unit 82 in the X and Y directions relative to the mold M, while causing the second measurement unit 82 to detect the distance to the surface of the mold M (the surface height of the mold M). This allows the second measurement unit 82 to measure the surface height distribution of the mold M.

[0060] In step S205, the control unit CNT estimates the position of the mold M in the stage coordinate system based on the measurement result in step S204. For example, the control unit CNT estimates the position of the mesa portion Me (feature portion) of the mold M in the stage coordinate system based on the surface height distribution of the mold M measured by the second measurement unit 82 in step S204.

[0061] Here, the surface height distribution of the mold M measured by the second measurement unit 82 in step S204 preferably includes measurement lines (measurement positions) 25a to 25d shown in FIG. 5A. FIG. 5A is a view of the mold M held by the mold holding unit 20 as viewed from below (in the -Z direction). Measurement lines 25a to 25b indicate lines (positions) for measuring the surface height distribution in the X direction by the second measurement unit 82, and are set so as to cross the edges of the mesa portion Me of the mold M. Measurement lines 25a to 25b are each set as lines extending in the X direction so as to cross the X-direction side of the mesa Me. Measurement line 25a and measurement line 25b may be parallel. On the other hand, measurement lines 25c to 25d indicate lines (positions) for measuring the surface height distribution in the Y direction by the second measurement unit 82, and are set so as to cross the edges of the mesa portion Me of the mold M. The measurement lines 25c and 25d are set as lines extending in the Y direction so as to cross the Y-direction side of the mesa Me. The measurement lines 25c and 25d may be parallel to each other.

[0062] In this way, in step S204, the second measurement unit 82 can measure the surface height distribution of the mold M in each of two directions (X direction and Y direction) that are orthogonal to each other in a plane parallel to the surface of the mold M (mesa portion Me). As a result, in step S205, the control unit CNT can estimate the position of the mesa portion Me in the X and Y directions in the stage coordinate system based on the surface height distribution in the X direction and the surface height distribution in the Y direction measured by the second measurement unit 82.

[0063] Furthermore, in the adjustment process, an adjustment member M' having recesses (steps) 26a-26d may be used, as shown in FIG. 5B . FIG. 5B is a view of the adjustment member M' held by the mold holding unit 20, viewed from below (in the -Z direction). The depth of each recess 26a-26d is preferably approximately 20 nm to 200 nm, but may be as low as approximately 1 μm. In this case, the surface height distribution of the adjustment member M' measured by the second measurement unit 82 in step S204 may include measurement lines (measurement positions) 27a-27d and 28a-28d shown in FIG. 5B. The measurement lines 27a-27d indicate lines (positions) for measuring the surface height distribution in the X direction by the second measurement unit 82, and are each set as lines extending in the X direction so as to intersect each recess 26a-26d. On the other hand, the measurement lines 28a to 28d indicate lines (positions) for measuring the surface height distribution in the Y direction by the second measurement unit 82, and are each set as lines extending in the Y direction so as to cross each of the recesses 26a to 26d.

[0064] In this way, when using an adjustment member M' including the recesses 26a to 26d, the surface height distribution including the measurement lines 27a to 27d and 28a to 28d is measured by the second measurement unit 82 in step S204. As a result, in step S205, the control unit CNT can estimate the position of the adjustment member M' in the stage coordinate system based on the surface height distribution of the adjustment member M' measured by the second measurement unit 82. Alternatively, the control unit CNT can estimate the positions of the recesses 26a to 26d in the stage coordinate system as the positions of the characteristic parts of the adjustment member M' in the stage coordinate system. Note that the adjustment member M' is provided with marks that are detected by the second detection unit 72 in step S202, and the positional relationship between the marks and the recesses 26a to 26d is guaranteed (i.e., it is known information).

[0065] If the adjustment member M' has a mesa portion Me, the position of the mesa portion Me in the stage coordinate system may be estimated. For example, in step S205, the control unit CNT can estimate the position of the mesa portion Me in the stage coordinate system as the position of the characteristic portion in the stage coordinate system based on the positions of the recesses 26a to 26d in the stage coordinate system. In this case, the positional relationship between the recesses 26a to 26d in the adjustment member M' and the mesa portion Me is guaranteed (i.e., it is known information). Therefore, the control unit CNT can estimate the position of the mesa portion Me in the stage coordinate system based on information indicating this positional relationship. Note that the recesses 26a to 26d may be provided inside or outside the mesa portion Me. Furthermore, it is possible to use a part of a pattern or a stepped shape provided on the adjustment member M' as the recesses 26a to 26d.

[0066] Returning to FIG. 4 , in step S206, the control unit CNT determines the offset of the second measurement unit 82 based on the position of the mesa portion Me (feature portion) estimated in step S203 and the position of the mesa portion Me (feature portion) estimated in step S205. The position of the mesa portion Me estimated from the detection result of the second detection unit 71 in step S203 and the position of the mesa portion Me estimated from the measurement result of the second measurement unit 82 in step S205 are obtained based on the same index (stage coordinate system). Therefore, the control unit CNT can determine the offset of the second measurement unit 82 based on the positions of the mesa portion Me estimated in steps S203 and S205. For example, the control unit CNT can determine the difference between the position of the mesa portion Me (feature portion) estimated in step S203 and the position of the mesa portion Me (feature portion) estimated in step S205 as the offset of the second measurement unit 82. The offset of the second measuring unit 82 determined in step S206 can be stored (held) in the storage unit. Next, in step S207, the control unit CNT carries out the mold M from the mold holding unit 20 using a mold transport mechanism (not shown).

[0067] As described above, the imprint apparatus 100 of this embodiment performs an adjustment process to determine the offset of the second measurement unit 82. By controlling the imprint process (i.e., the measurement of the surface height distribution of the mold M by the second measurement unit 82) based on the offset of the second measurement unit 82 determined by this adjustment process, it is possible to form a pattern of the imprint material on the substrate with high precision.

[0068] <Embodiment of Article Manufacturing Method> An article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, such as semiconductor devices, and elements having microstructures. The article manufacturing method of this embodiment includes a formation step of forming a pattern on a substrate using the imprint apparatus (imprint method) described above, a processing step of processing the substrate on which the pattern has been formed in the formation step, and a manufacturing step of manufacturing an article from the substrate processed in the processing step. The imprint apparatus performing the formation step can be adjusted using the adjustment method described above. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of this embodiment is advantageous over conventional methods in at least one of article performance, quality, productivity, and production cost.

[0069] The pattern of the cured product formed using the above-described imprinting apparatus is used permanently on at least a portion of various articles, or temporarily when manufacturing various articles. Examples of articles include electrical circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of electrical circuit elements include volatile or nonvolatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensor, and FPGA. Examples of molds include molds for imprinting.

[0070] The pattern of the cured product may be used as it is as at least a part of a component of the article, or may be used temporarily as a resist mask, which is removed after etching or ion implantation in a substrate processing step.

[0071] Next, a specific method for manufacturing an article when an imprinting apparatus is used as a molding apparatus will be described. As shown in Figure 6A, a substrate 1z such as a silicon wafer is prepared, on the surface of which a workpiece 2z such as an insulator is formed. Next, an imprinting material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. Here, the state in which multiple droplets of the imprinting material 3z have been applied to the substrate is shown.

[0072] As shown in Fig. 6B, the imprinting mold 4z is placed with the side on which the concave-convex pattern is formed facing the imprinting material 3z on the substrate. As shown in Fig. 6C, the substrate 1z to which the imprinting material 3z has been applied is brought into contact with the mold 4z, and pressure is applied. The imprinting material 3z fills the gap between the mold 4z and the workpiece 2z. In this state, when light is irradiated through the mold 4z as hardening energy, the imprinting material 3z hardens.

[0073] 6D , after the imprint material 3z is cured, the mold 4z is separated from the substrate 1z, forming a pattern of the cured imprint material 3z on the substrate 1z. In this cured material pattern, the recesses of the mold correspond to the protrusions of the cured material, and the protrusions of the mold correspond to the recesses of the cured material, i.e., the recess-protrusion pattern of the mold 4z is transferred to the imprint material 3z.

[0074] As shown in Fig. 6E, when etching is performed using the cured material pattern as an etching-resistant mask, portions of the surface of the workpiece 2z where no cured material or only a thin layer remains are removed, forming grooves 5z. As shown in Fig. 6F, when the cured material pattern is removed, an article is obtained in which grooves 5z are formed in the surface of the workpiece 2z. Here, the cured material pattern is removed, but it may also be used as an interlayer insulating film included in a semiconductor device or the like, i.e., a component of an article, without being removed after processing.

[0075] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0076] This application claims priority based on Japanese Patent Application No. 2023-187901, filed November 1, 2023, the entire contents of which are incorporated herein by reference.

[0077] 10: Light irradiation unit, 20: Mold holding unit, 30: Substrate holding unit, 32: Stage, 71: First detection unit, 72: Second detection unit, 81: First measurement unit, 82: Second measurement unit, 100: Imprint apparatus

Claims

1. An adjustment method for an imprinting apparatus that uses a mold held by a mold holding unit to form a pattern in an imprint material on a substrate held by a stage, comprising: a first estimation process for estimating the position of the member held by the mold holding unit based on the relative position between a mark on the member held by the mold holding unit and a mark on the stage detected by a detection unit; a second estimation process for estimating the position of the member based on the result of measurement by a measurement unit of the surface height distribution of the member held by the mold holding unit; and a determination process for determining an offset of the measurement unit based on the position of the member estimated in the first estimation process and the position of the member estimated in the second estimation process.

2. The adjustment method according to claim 1, characterized in that the component has a feature on its surface constituted by a step, and in the second estimation step, the position of the component is estimated based on the position of the feature obtained from the measurement results of the measurement unit.

3. The adjustment method described in claim 1, characterized in that the component has a feature on its surface that is constituted by a step and whose positional relationship with respect to the mark of the component is guaranteed, and in each of the first estimation process and the second estimation process, the position of the feature is estimated as the position of the component, and in the determination process, the offset is determined based on the position of the feature estimated in the first estimation process and the position of the feature estimated in the second estimation process.

4. An adjustment method described in any one of claims 1 to 3, characterized in that when the surface height distribution of the mold held by the mold holding unit is measured by the measurement unit, the movement of the stage on which the measurement unit is mounted is controlled based on the offset determined in the determination process.

5. An adjustment method according to any one of claims 1 to 4, characterized in that in the determination process, the difference between the position of the component estimated in the first estimation process and the position of the component estimated in the second estimation process is determined as the offset.

6. An adjustment method according to any one of claims 1 to 5, characterized in that in the second estimation process, the position of the component is estimated based on the results of measuring the surface height distribution of the component by the measuring unit in each of two mutually perpendicular directions within a plane parallel to the surface of the component.

7. The adjustment method according to any one of claims 1 to 6, characterized in that the stage mark is provided on a reference plate fixed to the stage.

8. An imprinting method comprising: an adjustment step of adjusting an imprinting apparatus using the adjustment method according to any one of claims 1 to 7; and a formation step of forming a pattern on a substrate using the imprinting apparatus adjusted by the adjustment step.

9. A method for manufacturing an article, comprising: a processing step of processing a substrate on which a pattern is formed using the imprint method described in claim 8; and a manufacturing step of manufacturing an article from the substrate processed in the processing step.

10. An imprinting apparatus which forms a pattern in an imprint material on a substrate using a mold, comprising: a mold holding unit which holds the mold; a stage which holds the substrate; a detection unit which detects the relative position between a mark on the mold and a mark on the substrate; a measurement unit which measures a surface height distribution of the mold; and a control unit, wherein the control unit estimates a position of the member held by the mold holding unit as a first position based on a result of detection by the detection unit of the relative position between the mark of the member held by the mold holding unit and a mark on the stage; estimates a position of the member held by the mold holding unit as a second position based on a result of measurement by the measurement unit of the surface height distribution of the member held by the mold holding unit; and determines an offset of the measurement unit based on the estimated first position and second position.

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