Inspection method, imprint method, and article manufacturing method

Abstract

To provide a technique advantageous for detecting a mistake of a mold to be mounted on an imprint device and a mistake of upper and lower pattern surfaces of the mold mounted on the imprint device.SOLUTION: To provide an inspection method for inspecting a state of a mold for imprinting a material on a substrate. The mold has a first surface including a region to be in contact with the material and a second surface opposite to the first surface. The inspection method includes a measurement step of performing height measurement of each of a first region, which is a central region, and a second region, which is a region outside the first region, of the first surface of the mold, and a determination step of determining, based on a result of the height measurement of each of the first region and the second region, whether the first surface and the second surface of the mold face in a correct direction, and determining whether a shape of the mold conforms to an assumed shape.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Imprinting technology, which uses a mold to form a pattern of an imprint material on a substrate, is known as a method for manufacturing articles such as semiconductor devices. In imprinting technology, the imprint material is supplied onto a substrate, and the mold is brought into contact with the imprint material, whereby the imprint material is cured and the mold is then removed from the cured imprint material. This forms a pattern of the imprint material on the substrate.

[0003] The molds used for imprinting are made of quartz glass or other materials, making them difficult to see. This raises concerns about the possibility of installing the wrong mold in the imprinting apparatus or installing the mold in the wrong direction. Patent Document 1 describes a technique that makes it possible to visually check the correct orientation of the mold and the installation direction in the imprinting apparatus by providing a notch in at least one of the mold's four corners. Patent Document 2 describes a technique that detects incorrect mold selection based on the presence or absence of a mesa portion. Patent Document 3 describes a technique that controls the imprinting operation based on the presence or absence of a core-out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5327421 [Patent Document 2] Patent No. 6779748 [Patent Document 3] Patent No. 6821408 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional techniques have been unable to detect the upside down position of the pattern surface of a mold mounted on an imprinting apparatus.

[0006] The present invention provides an advantageous technique for detecting whether a mold to be mounted on an imprinting apparatus is incorrect and whether the pattern surface of a mold mounted on the imprinting apparatus is upside down. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided an inspection method for inspecting the state of a mold for imprinting a material on a substrate, wherein the mold has a first surface including an area that contacts the material and a second surface opposite the first surface, the inspection method comprising: a measurement step of measuring the height of a first region, which is a central region of the first surface of the mold, and a second region, which is an area outside the first region; and a determination step of determining, based on the results of each height measurement, whether the first surface and the second surface of the mold are facing in the correct direction and whether the shape of the mold conforms to an expected shape. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an advantageous technique for detecting whether the mold to be mounted on the imprinting apparatus is incorrect and whether the pattern surface of the mold mounted on the imprinting apparatus is upside down. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of an imprint apparatus. [Figure 2] FIG. 10 is a diagram for explaining imprint processing. [Figure 3] FIG. 10 is a diagram showing an example of a mold configuration. [Figure 4] FIG. [Figure 5] FIG. 10 is a diagram showing the measurement area of ​​a mold. [Figure 6] 1 is a flowchart of an inspection method. [Figure 7]1 is a flowchart of an inspection method. [Figure 8] FIG. 10 is a diagram showing an example of a pattern portion having a non-measurable area. [Figure 9] 1 is a flowchart of an inspection method. [Figure 10] FIG. 10 is a diagram showing an evaluation table for determining measurement results. [Figure 11] 1 is a flowchart of an inspection method. [Figure 12] FIG. 10 is a diagram showing an evaluation table for determining measurement results. [Figure 13] 1 is a flowchart of an inspection method. [Figure 14] FIG. 10 is a diagram showing an evaluation table for determining measurement results. [Figure 15] 1 is a flowchart of an inspection method. [Figure 16] FIG. 10 is a diagram showing an evaluation table for determining measurement results. [Figure 17] 1 is a flowchart of an imprint method. [Figure 18] 1A to 1C are diagrams illustrating an article manufacturing method. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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.

[0011] First, an outline of an imprinting apparatus according to an embodiment will be described. The imprinting apparatus is an apparatus that brings an imprinting material supplied onto a substrate into contact with a mold and applies energy for curing to the imprinting material, thereby forming a pattern in a cured product to which the concave-convex pattern of the mold has been transferred.

[0012] The imprint material is a curable composition (sometimes referred to as an uncured resin) that cures when curing energy is applied. Examples of curing energy include electromagnetic waves and heat. Electromagnetic waves can be, for example, light with a wavelength selected from the range of 10 nm to 1 mm, such as infrared light, visible light, and ultraviolet light. The curable composition can be a composition that cures when irradiated with light or when heated. Among these, photocurable compositions that cure when irradiated with light contain at least a polymerizable compound and a photopolymerization initiator and may further contain a non-polymerizable compound or a solvent, as needed. 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 can be deposited on a substrate in the form of droplets, or in the form of islands or a film formed by connecting multiple droplets, using an imprint material supply device (not shown). The viscosity of the imprint material (at 25°C) may be, for example, 1 mPa·s or more and 100 mPa·s or less. Materials that can be used for the substrate include, for example, glass, ceramics, metal, semiconductor, and resin. If necessary, a member made of a material different from the substrate may be provided on the surface of the substrate. The substrate may be, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass.

[0013] (Configuration of imprint device) FIG. 1 is a diagram showing the configuration of an imprint apparatus 101 according to an embodiment. In this specification and the drawings, directions are indicated in an XYZ coordinate system in which the horizontal plane is the XY plane. Generally, a substrate is placed on a substrate stage so that its surface is parallel to the horizontal plane (XY plane). Therefore, in the following, the directions that are perpendicular to each other in a plane along the surface of the substrate stage on which the substrate is placed are referred to as the X-axis and Y-axis, and the direction perpendicular to the X-axis and Y-axis is referred to as the Z-axis. Furthermore, in the following, the directions that are parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are referred to as the X-direction, Y-direction, and Z-direction, respectively, and the directions of rotation around the X-axis, Y-axis, and Z-axis are referred to as the θX-direction, θY-direction, and θZ-direction, respectively.

[0014] The imprint apparatus 101 may include a light irradiation unit 102, a mold holding unit 103, a substrate holding unit 104, a supply unit 105, a control unit 106, a measurement unit 122, and a housing 123. The imprint apparatus 101 may further include a mold deformation mechanism 130 for deforming the mold 211. The mold deformation mechanism 130 can change the shape of the mold 211 by applying force to the side surfaces of the mold 211. The imprint apparatus 101 may further include a mold transport mechanism (not shown) that transports the mold 211 to the mold holding unit 103, and a substrate transport mechanism (not shown) that transports the substrate 111 to the substrate holding unit 104.

[0015] The light irradiation unit 102 irradiates ultraviolet light 108 to harden the imprint material (material). The light irradiation unit 102 may include a light source 109 that irradiates ultraviolet light 108, and an optical element 110 that corrects the ultraviolet light 108 irradiated from the light source 109 to light appropriate for imprinting. The imprint apparatus 101 of this embodiment employs a photocuring method as a method for hardening the imprint material. Therefore, the light irradiation unit 102 is provided to harden the imprint material. If the imprint apparatus 101 employs a thermal hardening method instead of a photocuring method, a heat source unit for hardening the imprint material would be provided instead of the light irradiation unit 102.

[0016] The mold holding unit 103 includes a chuck 115 that attracts and holds the mold 211 by vacuum suction force or electrostatic force, and a mold driving mechanism 116 that holds the chuck 115 and moves the mold 211 held by the chuck 115 together with the chuck. The mold 211 has, for example, a rectangular outer periphery and includes a pattern unit 203 on the surface facing the substrate 111, on which a concave-convex pattern to be transferred to the imprint material, such as a circuit pattern, is formed. The chuck 115 and the mold driving mechanism 116 each have an opening region 117 (opening) formed in their centers so that ultraviolet light 108 emitted from the light source 109 of the light irradiation unit 102 can be irradiated onto the substrate 111. By driving the mold 201 in the Z direction using the mold driving mechanism 116, a contacting step in which the mold 211 is brought into contact with the imprint material on the substrate 111 and a mold releasing step in which the mold 211 is separated from the cured imprint material can be performed. Actuators that can be used in the mold driving mechanism 116 include, for example, a linear motor or an air cylinder. The mold driving mechanism 116 may be composed of multiple driving systems, such as a coarse driving system and a fine driving system, in order to accommodate high-precision positioning of the mold 211. Furthermore, the mold driving mechanism 116 may include driving mechanisms not only for driving in the Z direction but also for driving in the X and Y directions. Furthermore, the mold driving mechanism 116 may have a position correction function in the θz direction and a tilt function (position correction function in the θx and θy directions) for correcting the inclination of the mold 211.

[0017] The substrate holding unit 104 may include a substrate chuck 119 that attracts and holds the substrate 111 by vacuum suction, and a substrate stage 120 that mechanically holds the substrate chuck 119 and moves the substrate 111 held by the substrate chuck 119 within the XY plane. When the mold 211 contacts the imprint material 114 on the substrate 111, the substrate holding unit 104 aligns the mold 211 with the substrate 111. A stage reference mark 121 that is used to align the mold 211 is disposed on the substrate stage 120. The stage reference mark 121 may be provided on the substrate chuck 119. An example of an actuator that can be used for the substrate stage 120 (substrate driving mechanism) is a linear motor. The substrate stage 120 may also be composed of multiple drive systems, such as a coarse movement drive system and a fine movement drive system, in the X and Y directions. Furthermore, it may have a drive system for correcting the position of the substrate 111 in the Z direction, a function for correcting the position of the substrate 111 in the θz direction, a tilt function for correcting the inclination of the substrate 111, and the like.

[0018] The operation of the imprint apparatus 101 in the contact step and the release step may be achieved by the substrate driving mechanism moving the substrate 111 in the Z direction, rather than by the mold driving mechanism 116 moving the mold 211 in the Z direction. Alternatively, the operation may be achieved by moving both the mold 211 and the substrate 111 relative to one another.

[0019] The supply unit 105 supplies uncured imprint material 114 onto the substrate 111. The supply unit 105 has multiple outlets (nozzles) formed therein, and droplets of the imprint material are ejected from the outlets onto the substrate 111. The supply unit 105 can be configured to push the imprint material 114 out of the outlets, for example, by utilizing the piezoelectric effect of a piezoelectric element. The control unit 106 generates a drive signal for driving the piezoelectric element, and drives the piezoelectric element to deform into a shape suitable for ejection. The control unit 106 can independently control the ejection of the imprint material from each outlet of the supply unit 105. The amount of imprint material 114 and the distribution of droplets supplied onto the substrate 111 from the multiple outlets of the supply unit 105 are determined as appropriate depending on the thickness of the imprint material pattern to be formed on the substrate 111, the density of the pattern to be formed, and the like.

[0020] The measurement unit 122 can include an alignment detector 127 and an imprint material observation unit 128. The alignment detector 127 can detect alignment marks formed on the substrate 111 and alignment marks formed on the mold 211. The imprint material observation unit 128 includes an imaging device such as a CCD camera, and can capture an image of the contact state between the imprint material 114 supplied to the substrate 111 and the mold 211. The imprint material observation unit 128 can observe the states of the contact process and the mold release process.

[0021] The control unit 106 comprehensively controls the operation of each component of the imprint apparatus 101. The control unit 106 is configured, for example, by a computer including a CPU and memory. The control unit 106 is connected to each component of the imprint apparatus 101 via a line and can control each component according to a program. The control unit 106 controls the operation of the mold holding unit 103, the substrate holding unit 104, and the supply unit 105 based on the measurement results of the measurement unit 122. The control unit 106 can also measure the relative position between the mold 211 and the substrate 111 based on the detection results of the alignment detector 127. For example, the control unit 106 measures the positional deviation in the X and Y directions between the alignment mark of the mold 211 and the alignment mark of the substrate 111. The control unit 106 can also determine the success or failure of the contact process and the mold release process based on the imaging results of the imprint material observation unit 128.

[0022] The control unit 106 may be disposed inside the housing of the imprint apparatus 101, or may be disposed outside the housing of the imprint apparatus 101. When the control unit 106 is disposed outside the housing of the imprint apparatus 101, for example, the control unit 106 may be provided in a server connected to the imprint apparatus 101 via a network. The control unit 106 may be configured from multiple computers instead of a single computer.

[0023] The housing 123 can include a base surface plate 124 on which the substrate holding part 104 is placed, a bridge surface plate 125 on which the mold holding part 103 is fixed, and a support 126 for supporting the bridge surface plate 125.

[0024] (About imprint processing) Next, an imprint process for forming a pattern of an imprint material on a substrate 111 using the imprint apparatus 101 will be described.

[0025] The control unit 106 causes the substrate 111 carried into the imprint apparatus 101 to be placed on and held by the substrate chuck 119 of the substrate stage 120 using the substrate transport mechanism. The substrate holding unit 104 holding the substrate 111 moves to a position where the imprint material is supplied by the supply unit 105. Then, the supply unit 105 supplies the imprint material 114 to a predetermined pattern formation region (shot region) on the substrate 111 (supply step).

[0026] Next, the control unit 106 moves the substrate holding unit 104 so that the pattern formation region on the substrate 111 to which the imprint material has been supplied is positioned directly below the pattern portion 203 of the mold 211. The control unit 106 drives the mold driving mechanism 116 to bring the imprint material 114 on the substrate 111 into contact with the pattern portion 203 of the mold 211 (contact step). At this time, the imprint apparatus 101 aligns the mold 211 with the substrate 111 based on the detection results of the alignment marks on the mold 211 and the substrate 111 detected by the alignment detector 127. Furthermore, the mold deformation mechanism 130 can deform the mold 211 based on the detection results of the alignment marks.

[0027] This contact step causes the imprint material 114 to fill the concave and convex portions formed in the pattern portion 203 of the mold 211. With the imprint material 114 filling the pattern, the control unit 106 causes the light irradiation unit 102 to irradiate ultraviolet light 108 from above the mold 211. The imprint material 114 is hardened by the ultraviolet light 108 that has passed through the mold 211 (hardening step). Then, after the imprint material 114 has hardened, the control unit 106 drives the mold driving mechanism 116 to separate the mold 211 from the hardened imprint material 114 (mold releasing step).

[0028] As a result, a three-dimensional pattern of the imprint material 114 is formed in the pattern formation region on the substrate 111, which is an inverse of the concave-convex portion formed in the pattern portion 203 of the mold 211. In this way, by performing a series of imprint operations from the supplying step to the releasing step multiple times while changing the pattern formation region by driving the substrate holding unit 104, multiple patterns of the imprint material 114 can be formed on one substrate 111.

[0029] (About types) Next, an example of the configuration of the mold 211 will be described. Due to the characteristic of imprint technology that a pattern is formed by contact between the mold and the imprint material on the substrate, the molds used are processed into a characteristic shape to ensure performance. The shape of the mold is generally specified by the imprint device manufacturer, and there are various shapes. Here, an example of a typical shape of the mold 211 is shown.

[0030] FIG. 3 shows an example of a plan view and a cross-sectional view along line A-A' of the mold 211. The mold 211 is made of, for example, synthetic quartz and has a square outer shape, with each side having a length of, for example, 152 mm and a thickness of, for example, 6.35 mm. The mold 211 has a first surface F1 including an area that contacts the imprint material on the substrate and a second surface F2 opposite the first surface F1. A mesa M that protrudes toward the substrate 111 is formed in the central area of ​​the first surface F1 of the mold 211, and a pattern portion 203 is formed on the surface of this mesa M. The outer peripheral portion 204 is a region that surrounds the mesa M. The mesa M is formed so that the outer peripheral portion 204 does not contact the substrate 111 during the contact process. For example, the step between the outer peripheral portion 204 and the mesa M can be approximately 30 μm.

[0031] Furthermore, a core-out 205, which is a recess, is formed on the second surface F2 of the mold 211. The core-out 205 has a shape for controlling deformation of the mesa M to ensure smooth contact and release during imprinting. In the example of FIG. 3, the core-out 205 has a cylindrical cavity shape. The thickness of the bottom of the core-out 205 (excluding the thickness of the mesa M) can be determined as appropriate by the imprinting apparatus manufacturer. In one example, the thickness of the bottom of the core-out 205 can be approximately 1 mm.

[0032] 1 and 2(a) show a mold 211 having a configuration similar to that shown in FIG. 3. As shown in FIG. 1, a light-transmitting member 113 is placed in an opening region 117 in the mold holding part 103, forming a space 112 surrounded by a part of the opening region 117 and the core-out 205 as a closed space. The pressure within the space 112 thus formed can be adjusted by a pressure adjustment mechanism (not shown). When pressure is applied within the space 112, the pattern portion 203 can be deformed downwardly convex (convex toward the substrate).

[0033] The imprinting process will be described with reference to Figures 2(b) to 2(e). Figure 2(b) shows a state in which the imprint material 114 is supplied onto the substrate 111 by the supply unit 105 (supplying step), and the space 112 is pressurized, deforming the pattern portion 203 into a downward convex shape. Next, the contacting step is started, and the mold driving mechanism 116 moves the mold 201 downward in the Z direction, bringing the pattern portion 203 into contact with the imprint material 114 on the substrate 111 (contacting step). At this time, as shown in Figure 2(c), contact with the imprint material 114 begins from the center of the pattern portion 203. This makes it possible to prevent gas from being trapped between the recesses of the pattern portion 203 and the imprint material 114.

[0034] 2(d) shows a state in which the mold 201 has been further pressed against the substrate 111 and the pressure in the space 112 has been weakened. This allows the imprint material 114 to fill every corner of the minute recesses in the pattern portion 203. Thereafter, the imprint material 114 is irradiated with ultraviolet light 108 to harden the mold 201 (hardening step), and the mold 201 is separated from the imprint material 114 (mold release step). FIG. 2(e) shows the state after the mold release step is completed.

[0035] The above describes an example of a mold 211 having a mesa M and a core-out 205. As mentioned above, the shape of the mold is generally specified by the imprinting apparatus manufacturer, and there are various shapes. The mesa and core-out are options that can be selected depending on the purpose and performance. Therefore, as shown in Figures 4(a) to (d), there can be, for example, the following four types of mold shapes used in imprinting apparatuses. (a) With mesa, with core-out, (b) No mesa, with core-out; (c) with mesa, without core-out; (d) No mesa, no core-out.

[0036] In this embodiment, the imprint apparatus 101 includes a means for detecting the presence or absence of a mesa and a core-out of the mold 211. For example, as shown in FIG. 1 , the imprint apparatus 101 may include a mold sensor 150, which is a measuring instrument for measuring the surface of the mold 211. In one example, the mold sensor 150 is provided at an end of the substrate chuck 119 that is not covered by the substrate and measures the distance in the Z direction to the object (mold 211) above. The control unit 106 can determine the height of the surface of the mold 211 based on the measurement results of the mold sensor 150. Furthermore, by moving the substrate stage 120 in the X and Y directions, the mold sensor 150 can measure any position on the surface of the mold 211. Therefore, the control unit 106 can determine the presence or absence of a mesa M of the mold 211 based on the measurement results of the mold sensor 150 at multiple positions on the mold 211. For example, the control unit 106 controls the substrate stage 120 to acquire the measurement results of the mold sensor 150 when the mold sensor 150 is positioned below the outer periphery 204 of the mold 211. Next, the control unit 106 controls the substrate stage 120 to acquire the measurement results of the mold sensor 150 when the mold sensor 150 is positioned below the center of the mold 211. The control unit 106 determines the presence or absence of the mesa M based on the difference between these acquired measurement results.

[0037] The control unit 106 can also use the mold sensor 150 to determine whether or not there is a core-out 205 in the mold 211. For example, the control unit 106 acquires a measurement (height measurement) result by the mold sensor 150 when the pressure in the space 112 is normal pressure (atmospheric pressure). Next, the control unit 106 acquires a measurement result by the mold sensor 150 when pressurizing the space 112 to deform the pattern portion 203 downwardly convex. The control unit 106 determines whether or not there is a core-out 205 based on the difference between these acquired measurement results.

[0038] The type and mounting position of the type sensor 150, and the method of determining the presence or absence of a mesa and a core-out are not limited to the above examples. Other examples are described in Patent Document 2 (Japanese Patent No. 6779748) and Patent Document 3 (Japanese Patent No. 6821408).

[0039] In the following examples, we will explain how to check the shape of the mold for combinations of whether or not there is a mesa and whether or not there is a core-out.

[0040] Example 1 In the first embodiment, a process will be described in which, when a user sets in the imprint apparatus 101 that the mold to be used is a mold with a mesa and a core-out (FIG. 4(a)), a determination is made as to whether the mold 211 actually placed in the apparatus is in a correct state with respect to the setting information. The shape of the mold set as the one to be used for imprinting is called the "expected shape." The expected shape can be determined by information set by the user. In the first embodiment, since the user sets that the mold to be used is a mold with a mesa and a core-out, the expected shape is a shape in which a mesa is present and a core-out is present.

[0041] 5, the measurement regions of the mold 211 will be described. The control unit 106 controls the substrate stage 120 and the mold sensor 150 to perform height measurements in the following three regions. (1) A first region 51, which is a central region of the first surface F1 where a mesa may exist; (2) A second region 52 on the first surface F1, which is located outside the first region 51 and on the opposite side, where a core-out may exist; (3) A third region 53 on the first surface F1, which is an area outside the second region 52 and inside the outer edge of the mold 211.

[0042] The control unit 106 determines whether the height measurement results for each region are within the allowable range of the expected mold thickness. The allowable range of the expected mold thickness can be determined, for example, according to the allowable mold thickness error range pre-specified for the imprinting apparatus. For example, if the allowable error range for a mold thickness of 6.35 mm is ±100 μm pre-specified for the imprinting apparatus, an error can be determined if the height measurement results for each region are outside the ±100 μm range of the expected position. If the amount of positional fluctuation due to vibration or the like of the mold sensor 150 and the mold holding unit 103 is known, this amount can be taken into account when making the determination. If the measurement range of the mold sensor 150 is exceeded and an error is output from the mold sensor 150, this can be treated as a measurement error.

[0043] The first region 51 will now be described. The first region 51 is the central region of the first surface F1 where a mesa can exist. However, depending on the type of mold, a mesa may not exist. The size of the mesa can be changed for each mold depending on the application. In an imprinting apparatus that forms a pattern by physically contacting the mold with the imprint material on the substrate, information about the height of the mold at the time of contact is extremely important. Incorrect information not only results in incorrect pattern formation, but can also lead to damage to the mold. The apparatus must also know the first region 51 in order to measure the mesa height. For the reasons mentioned above, the user generally inputs the mesa size into the apparatus as a parameter. The apparatus uses this size to measure the height of the first region 51.

[0044] The second region 52 will now be described. The second region 52 is a region of the first surface F1 that is located outside the first region 51 and where a core-out may exist on the opposite side. The second region 52 can be determined from the core-out size specified by the manufacturer of the imprinting apparatus. However, depending on the type of mold, there may be cases where a core-out does not exist.

[0045] The third region 53 will now be described. The third region 53 is a region of the first surface F1 that is outside the second region 52 and inside the outer edge of the mold 211. Regardless of the type of mold, no mesa is formed in the third region 53, and no core-out is formed on the opposite side of the third region 53. The outer edge of the mold 211 can be determined from the mold size specified by the apparatus.

[0046] 6, an inspection method for inspecting the state of the mold 211 held by the chuck 115 in the first embodiment will be described. A program according to the flowchart shown in FIG. 6 is stored in a storage device in the control unit 106, for example, and executed by a processor (CPU) in the control unit 106.

[0047] In S100, the control unit 106 uses the mold sensor 150 to measure the height of the first region 51 (measurement 1) and the height of the second region 52 (measurement 2) (measurement process). After the measurement process, the process proceeds to a determination process in which the state of the mold 211 is determined. The determination process may include, based on the results of each height measurement, determining whether the first surface F1 having the pattern portion 203 of the mold 211 and the second surface F2 on the opposite side are oriented in the correct direction and whether the shape of the mold 211 matches the expected shape. "The first surface F1 and the second surface F2 on the opposite side are oriented in the correct direction" refers to a state in which the first surface F1 faces downward, i.e., toward the substrate stage 120, and the second surface F2 faces upward. Hereinafter, the up-down orientation of the first surface F1 and the second surface F2 will be referred to as "front and back."

[0048] In the example of FIG. 6, the determination process includes the following steps S104 to S110. In step S104, the control unit 106 determines whether the results of measurements 1 and 2 both indicate a measurement error. If the results of measurements 1 and 2 both indicate a measurement error, this indicates that no measurement object is present within the measurement range of the mold sensor 150 in either the first region 51 or the second region 52. This occurs when the mold 211 held by the chuck 115 is upside down, with the opening side of the core-out 205 facing the substrate stage. Therefore, if the results of measurements 1 and 2 both indicate a measurement error, the control unit 106 outputs a wrong-side-up error (S105).

[0049] If both Measurement 1 and Measurement 2 are successful, the process proceeds to S108. S108 is a step of determining whether the shape of the mold 211 differs from the expected shape based on whether the difference between the measurement values ​​obtained in Measurement 1 and Measurement 2 is within a specified range. In this step, the control unit 106 checks whether there is a height difference between the first region 51 and the second region 52 corresponding to a mesa. For example, if it is confirmed that the first region 51 is convex downward relative to the second region 52 within a specified range (e.g., 30 μm ± 1 μm), it is determined that a mesa exists in the first region 51. In this case, the process proceeds to S110, which is a core-out confirmation step. Otherwise, it is determined that the shape of the mold 211 differs from the expected shape, i.e., that no mesa exists in the first region 51, and the control unit 106 outputs a mold error (S109).

[0050] As described above, the core-out confirmation in S110 can be performed based on the difference between the height measurement result before deforming the pattern portion 203 into a downward convex shape and the height measurement result after applying pressure to the space 112 to deform the pattern portion 203 into a downward convex shape. However, the method of core-out confirmation is not limited to this. The core-out confirmation may involve pressurizing the space 112 by a pressure adjustment mechanism, which is also performed during imprinting. Therefore, the core-out confirmation involves the risk of dropping and damaging the mold due to the pressure applied to the space 112 if the wrong mold is installed or if the mold is installed upside down. In contrast, the inspection method of this embodiment outputs a wrong-side-up error (S105) or wrong mold error (S109), thereby minimizing the number of times the core-out confirmation in S110 is performed in a mounting error state. Therefore, the core-out confirmation can be performed more safely.

[0051] With reference to FIG. 7, an example of an inspection method that adds height measurement of the third region 53 and abnormality determination of the mold sensor 150 will be described. In FIG. 7, the same steps as those in the flowchart of FIG. 6 are assigned the same reference numerals, and their description will be omitted. In FIG. 7, S101 is performed instead of S100, and S102 is added before S104. In the measurement step S101, the control unit 106 uses the mold sensor 150 to perform height measurement of the first region 51 (measurement 1) and the second region 52 (measurement 2), as well as height measurement of the third region 53 (measurement 3). In S102, the control unit 106 determines whether the results of Measurement 1, Measurement 2, and Measurement 3 all indicate measurement errors. If the results of Measurement 1, Measurement 2, and Measurement 3 all indicate measurement errors, the control unit 106 determines that the mold sensor 150 is abnormal (broken) (S103).

[0052] Next, an example of an inspection method in which determination of unmeasurable areas is added will be described. The result of height measurement of the first region 51 may result in a measurement error due to the depth, shape, material, etc. of the pattern formed on the mesa. Specifically, for example, the result of height measurement of the first region 51 may result in a measurement error in the following cases. A deep pattern that exceeds the measurement range of the pattern sensor 150 exists in the pattern portion 203. The pattern portion 203 has a portion 81 in which a material is used that makes it difficult to obtain reflected light from the surface, as shown in FIG. 8 . The pattern portion 203 has a pattern 82 that is inclined in the height direction, as shown in FIG.

[0053] In the case of such a mold, it is necessary to shift the measurement position to obtain measurement results, but it is difficult to identify the cause of the measurement error based on the measurement results of the first area 51 alone, as there is the possibility of the above-mentioned mold being incorrect, the front and back being incorrect, or a mold sensor malfunction.In contrast, in the example shown below, by constructing a decision flow using measurement results from three locations, it is possible to determine whether or not there is a non-measurable area in the pattern portion of the mold that cannot be measured.

[0054] Referring to FIG. 9, an example of an inspection method that includes a check for the presence of an unmeasurable area will be described. In FIG. 9, the same steps as those in the flowcharts of FIGS. 6 and 7 are denoted by the same reference numerals, and their description will be omitted. Comparing FIG. 9 with FIG. 7, S106 has been added between S104 and S108 in FIG. 9. In S106, the control unit 106 determines whether only the result of the height measurement (Measurement 1) of the first region 51 indicates a measurement error. If only the result of Measurement 1 indicates a measurement error, the control unit 106 determines that there may be an unmeasurable area in the pattern section 203 (S107). In this case, since there are no measurements of the first region 51, it is not possible to confirm whether the mounted mold 211 has the user-specified shape. Therefore, the process cannot proceed to S110, which checks the mesa, and the process is terminated due to an error indicating the presence of an unmeasurable area. To prevent this situation, a user interface may be implemented that allows the user to specify a measurable position in the first region 51, allowing the measurement position to be changed by user instruction. Alternatively, multiple locations in the first region 51 may be automatically measured, and once measurement values ​​are obtained, the measurement values ​​may be used to continue the process.

[0055] Figure 10 shows an evaluation table for judging the measurement results when the expected shape is with or without a mesa and core-out. This evaluation table shows the measurement success / error for each area, mesa judgment, core-out confirmation, expected shape judgment, and prediction for the judgment.

[0056] As shown in FIG. 10, only when all measurements of the first area 51, the second area 52, and the third area 53 are successful, the mesa confirmation is successful, and the core-out confirmation is successful is the evaluation as "correct" (Case C1). If the evaluation is "correct," proceeding to the imprint process is permitted. Otherwise, the evaluation is "incorrect," "possible error," or "unable to determine." In these cases, proceeding to the imprint process is prohibited. In this case, the control unit 106 notifies the user of the content described in "Cause." As a result, safety is ensured and trouble recovery support can be prompted.

[0057] The judgment conditions that do not exist in the flow of Figure 9 (cases C12 and C13) are cases that are assumed not to exist in reality. Case C12 will be explained. The third region 53 is an area where measurement is possible even if the mold is upside down or the mold is incorrect. The only expected cause of a measurement error in this area is case C14, which is a mold sensor abnormality. In the case of a mold sensor abnormality, it is expected that there will be measurement errors in both the first region 51 and the second region 52. Therefore, case C12, in which only the third region 53 has a measurement error, does not basically exist. However, if such a case actually occurs, it is preferable to set up a sequence that drops to the "judgment impossible" flow and does not proceed to the imprint process, as a safe judgment.

[0058] Case C13 will now be described. In case C13, only the second region 52 experienced a measurement error, while the first region 51 and the third region 53 were measurable. Essentially, if the first region 51 and the second region 52 are reversed, a measurement error will occur in both, but if the reverse is correct, both should be measurable even if the mesa or core-out conditions are incorrect. Therefore, case C13 is an unexpected case, and is therefore "unable to judge." Even if case C13 does occur, as with case C12, it is preferable to set up a sequence that drops the process to "unable to judge" and does not proceed to the imprint process, as a safe judgment.

[0059] We have explained an example of an inspection method for a mounted mold when a mold with a mesa and core-out is assumed, as shown in Figure 4(a). This inspection method makes it possible to show the user any errors in the mounted mold and their causes, enabling early troubleshooting.

[0060] Example 2 In Example 2, the assumed shape is one with no mesa but with a core-out, as shown in FIG. 4(b). A flowchart of the inspection method for this assumed shape is shown in FIG. 11. The flow in FIG. 11 is similar to the flow in FIG. 9, with the only difference being that the logic in S108 is reversed (YES and NO are reversed) due to the difference in the assumed shape. Specifically, in this example, in S108, the control unit 106 determines whether the first region 51 is convex downward relative to the second region 52 within a specified range (e.g., 30 μm ± 1 μm). If no such downward convexity is detected, the mold 211 has no mesa, as expected, and processing can proceed to core-out confirmation in S110. On the other hand, if such a downward convexity is detected, it is determined that the mold 211 differs from the assumed shape and a mesa is present, and the control unit 106 outputs a mold error error (S109).

[0061] Fig. 12 shows an evaluation table for determining the measurement results when the assumed shape is without mesa and with core-out. Fig. 12 also has determination conditions (cases C21 and C22) that do not exist in the flow of Fig. 11. Cases C21 and C22 are the same as cases C12 and C13 in the first embodiment, respectively, and therefore their explanation will be omitted.

[0062] Example 3 In Example 3, the assumed shape is one with a mesa but without a core-out, as shown in Fig. 4(c). A flowchart of the inspection method for this assumed shape is shown in Fig. 13.

[0063] 9 and 13, due to differences in the assumed shapes, the conclusions reached when measurements 1 and 2 are both measurement errors in S104 are different from the conclusions reached when it is determined in S108 that there is no mesa. In FIG. 13, if measurements 1 and 2 are both measurement errors in S104, the control unit 106 determines in S115 that the mounted mold has a core-out and that the mold is upside down. Therefore, the control unit 106 outputs a mold error and a front / back error. Furthermore, if it is determined in S108 that there is no mesa in the mold 211, the control unit 106 determines in S119 that the mounted mold is either a mold without a mesa (i.e., a mold error) or that the mold is upside down.

[0064] Fig. 14 shows an evaluation table for determining the measurement results when the assumed shape is with a mesa and without a core-out. Fig. 14 also has determination conditions (cases C31 and C32) that do not exist in the flow of Fig. 13. Cases C31 and C32 are the same as cases C12 and C13 in the first embodiment, respectively, and therefore their explanation will be omitted.

[0065] Example 4 In Example 4, the assumed shape is one without a mesa and without a core-out, as shown in Fig. 4(d). A flowchart of the inspection method for this assumed shape is shown in Fig. 15.

[0066] Comparing FIG. 9 with FIG. 15, due to the difference in the assumed shape, first, the conclusions when both Measurement 1 and Measurement 2 result in measurement errors in S104 are different. In FIG. 15, when Measurement 1 and Measurement 2 both result in measurement errors in S104, in S115, the control unit 106 determines that the mounted mold has a core-out and that the mold is upside down. Therefore, the control unit 106 outputs a mold error and a front / back error. In other words, this is the same as in Example 3 (FIG. 13).

[0067] Next, comparing FIG. 9 with FIG. 15, the logic in S108 is reversed (YES and NO are reversed) due to the difference in the expected shape. Specifically, in this embodiment, in S108, the control unit 106 determines whether the first region 51 is convex downward relative to the second region 52 within a specified range (e.g., 30 μm±1 μm). If such a downward convexity is not detected, the mold 211 does not have a mesa as expected, and processing can proceed to core-out confirmation in S110. On the other hand, if such a downward convexity is detected, it is determined that the mold 211 differs from the expected shape and a mesa is present, and the control unit 106 outputs a mold error error (S109). In other words, this is the same as in Example 2 (FIG. 9).

[0068] Fig. 16 shows an evaluation table for determining the measurement results when the assumed shape is without mesa and without core-out. Fig. 16 also has determination conditions (cases C41 and C42) that do not exist in the flow of Fig. 15. Cases C41 and C42 are the same as cases C12 and C13 in the first embodiment, respectively, and therefore their explanation will be omitted.

[0069] The above various examples have shown examples of inspection methods for mounted molds when the expected shapes are different. These inspection methods can indicate to the user any errors in the mounted molds and their causes, enabling early troubleshooting. The inspection methods in the above-described embodiments can detect not only the wrong mold to be mounted in the imprinting apparatus and the wrong orientation of the mounted mold, but also the wrong front and back of the mounted mold.

[0070] <Embodiments of the Imprint Method> FIG. 17 is a flowchart showing an imprint method including the above-described inspection method.

[0071] In S171, the control unit 106 sets information about the shape of the mold to be used for imprinting (setting step). The information about the shape of the mold to be used for imprinting can be input by the user via a user interface. The information about the shape of the mold includes information about the presence or absence of a mesa and the presence or absence of a core-out, as described above. The information about the shape of the mold input by the user is stored, for example, in a memory unit within the control unit 106. The information stored in the memory unit corresponds to the "expected shape" described above.

[0072] Thereafter, the mold is carried into the imprint apparatus 101 by the mold transport mechanism, and the mold is mounted on the mold holding unit 103. In S172, the control unit 106 inspects the state of the mold mounted on the mold holding unit 103 according to the inspection method in the embodiment corresponding to the assumed shape among the above-mentioned embodiments, and determines whether the state of the mold matches the information set in the setting step (inspection step).

[0073] If it is confirmed in the inspection step that the state of the mold matches the information set in the setting step, the control unit 106 carries out a processing step in which the mold is used to imprint a material on a substrate. In the processing step, an imprint process including the supply step, contact step, curing step, and mold release step described above is performed. If it is not confirmed in the inspection step that the state of the mold matches the information set in the setting step, the control unit 106 does not proceed to the processing step.

[0074] <Embodiment of an article manufacturing method> The pattern of the cured product formed using the imprinting apparatus is used permanently on at least a portion of various articles, or temporarily when manufacturing various articles. Examples of articles include electrical circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of electrical circuit elements include volatile or nonvolatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGAs. Examples of molds include molds for imprinting.

[0075] 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.

[0076] Next, an article manufacturing method will be described with reference to Fig. 18. In step SA, a substrate 1z such as a silicon substrate having a workpiece 2z such as an insulator formed on its surface is prepared, and then an imprint material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. Here, a state in which multiple droplets of the imprint material 3z have been applied to the substrate is shown.

[0077] In step SB, the imprinting mold 4z is placed facing the imprinting material 3z on the substrate, with the side on which the concave-convex pattern is formed. In step SC, 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.

[0078] In step SD, after the imprint material 3z is cured, the mold 4z is separated from the substrate 1z, forming a pattern of the cured product of the imprint material 3z on the substrate 1z. In this cured product pattern, the recesses of the mold correspond to the protrusions of the cured product, and the protrusions of the mold correspond to the recesses of the cured product, i.e., the recess-protrusion pattern of the mold 4z is transferred to the imprint material 3z.

[0079] In step SE, etching is performed using the cured material pattern as an etching-resistant mask, and portions of the surface of the workpiece 2z where no cured material or only a thin layer remains are removed, forming grooves 5z. In step SF, the cured material pattern is removed, resulting in an article with grooves 5z 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 element or the like, i.e., a component of an article, without being removed after processing.

[0080] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0081] The disclosure of the present specification includes at least the following techniques. (Item 1) 1. A method of inspecting a condition of a mold for imprinting a material on a substrate, the mold having a first surface including an area for contacting the material and a second surface opposite the first surface, the method comprising: a measuring step of measuring the height of a first region, which is a central region of the first surface of the mold, and a second region, which is a region outside the first region; a determining step of determining whether the first surface and the second surface of the mold are facing in the correct direction and whether the shape of the mold matches an expected shape based on the results of the respective height measurements; An inspection method comprising: (Item 2) When the assumed shape is a shape in which a mesa is present and a core-out is present, or when the assumed shape is a shape in which a mesa is not present and a core-out is present, 2. The inspection method according to item 1, wherein in the determination step, if both the result of measuring the height of the first region and the result of measuring the height of the second region are measurement errors, it is determined that the first surface and the second surface of the mold are not oriented in the correct direction. (Item 3) When the assumed shape is a shape in which a mesa is present and a core-out is not present, or when the assumed shape is a shape in which a mesa is not present and a core-out is not present, 2. The inspection method according to item 1, wherein, in the determination step, if both the result of measuring the height of the first region and the result of measuring the height of the second region are measurement errors, it is determined that a core-out exists in the mold and that the first surface and the second surface of the mold are not facing in the correct direction. (Item 4) 4. The inspection method according to any one of items 1 to 3, wherein in the determination step, it is determined whether or not the shape of the mold conforms to the expected shape depending on whether or not a difference between a measurement value obtained by measuring the height of the first region and a measurement value obtained by measuring the height of the second region is within a specified range. (Item 5) When the assumed shape is a shape in which a mesa and a core-out are present, In the determination step, if the difference is not within the specified range, it is determined that no mesa exists in the mold and the shape of the mold does not match the expected shape. 5. The inspection method according to item 4. (Item 6) When the assumed shape is a shape in which no mesa exists and a core-out exists, or when the assumed shape is a shape in which no mesa exists and a core-out exists, In the determination step, if the difference is within the specified range, it is determined that a mesa exists in the mold and the shape of the mold does not conform to the assumed shape. 5. The inspection method according to item 4. (Item 7) When the assumed shape is a shape in which a mesa is present and a core-out is not present, In the determination step, if the difference is not within the specified range, it is determined that there is no mesa in the mold and the shape of the mold is different from the expected shape, or that the first surface and the second surface of the mold are not oriented in the correct direction. 5. The inspection method according to item 4. (Item 8) 8. The inspection method according to any one of items 1 to 7, further comprising a confirmation step of performing processing to confirm the presence of a core-out when it is determined in the determination step that the shape of the mold conforms to the expected shape. (Item 9) the measuring step further includes a step of measuring the height of a third region of the first surface of the mold that is outside the second region, 9. The inspection method according to any one of items 1 to 8, wherein in the determination step, if the results of the height measurement of the first area, the results of the height measurement of the second area, and the results of the height measurement of the third area all indicate measurement errors, it is determined that the measuring instrument used for the height measurements is abnormal. (Item 10) 10. The inspection method according to any one of items 1 to 9, wherein in the determination step, if only the result of measuring the height of the first region is a measurement error, it is determined that an unmeasurable region exists in the first region. (Item 11) a setting step of setting information on the shape of the mold; an inspection step of inspecting the state of the mold mounted on the mold holding unit according to the inspection method of any one of items 1 to 10, and determining whether the state of the mold matches the information set in the setting step; a processing step of imprinting a material on a substrate using the mold when it is confirmed in the inspection step that the state of the mold matches the information set in the setting step; An imprint method comprising: (Item 12) Forming a pattern on a substrate according to the imprinting method of item 11; processing the substrate on which the pattern is formed; and manufacturing an article from the processed substrate.

[0082] 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. [Explanation of symbols]

[0083] 101: imprinting device, 103: mold holding unit, 104: substrate holding unit, 105: supply unit, 106: control unit, 111: substrate, 211: mold

Claims

1. 1. A method of inspecting a condition of a mold for imprinting a material on a substrate, the mold having a first surface including an area for contacting the material and a second surface opposite the first surface, the method comprising: a measuring step of measuring the height of a first region, which is a central region, of the first surface of the mold, and a second region, which is a region outside the first region; a determining step of determining whether the first surface and the second surface of the mold are oriented in the correct direction and whether the shape of the mold matches an expected shape based on the results of the height measurements; An inspection method comprising:

2. When the assumed shape is a shape in which a mesa is present and a core-out is present, or when the assumed shape is a shape in which a mesa is not present and a core-out is present, 2. The inspection method according to claim 1, wherein the determination step determines that the first surface and the second surface of the mold are not facing in the correct direction if both the result of the height measurement of the first region and the result of the height measurement of the second region are measurement errors.

3. When the assumed shape is a shape in which a mesa is present and a core-out is not present, or when the assumed shape is a shape in which a mesa is not present and a core-out is not present, 2. The inspection method according to claim 1, wherein, in the determination step, if both the result of the height measurement of the first region and the result of the height measurement of the second region are measurement errors, it is determined that a core-out exists in the mold and that the first surface and the second surface of the mold are not facing in the correct direction.

4. 2. The inspection method according to claim 1, wherein in the determination step, it is determined whether the shape of the mold conforms to the expected shape depending on whether the difference between the measurement value obtained by measuring the height of the first region and the measurement value obtained by measuring the height of the second region is within a specified range.

5. When the assumed shape is a shape in which a mesa and a core-out are present, In the determination step, if the difference is not within the specified range, it is determined that no mesa exists in the mold and the shape of the mold does not match the expected shape.

5. The inspection method according to claim 4.

6. When the assumed shape is a shape in which no mesa exists and a core-out exists, or when the assumed shape is a shape in which no mesa exists and a core-out exists, In the determination step, if the difference is within the specified range, it is determined that a mesa exists in the mold and the shape of the mold does not conform to the assumed shape.

5. The inspection method according to claim 4.

7. When the assumed shape is a shape in which a mesa is present and a core-out is not present, In the determination step, if the difference is not within the specified range, it is determined that there is no mesa in the mold and the shape of the mold is different from the expected shape, or that the first surface and the second surface of the mold are not oriented in the correct direction.

5. The inspection method according to claim 4.

8. 2. The inspection method according to claim 1, further comprising a confirmation step of performing a process to confirm the presence of a core-out when it is determined in the determination step that the shape of the mold conforms to the expected shape.

9. the measuring step further includes a step of measuring the height of a third region of the first surface of the mold that is located outside the second region, 2. The inspection method according to claim 1, wherein the determination step determines that the measuring instrument used for the height measurement is abnormal if the results of the height measurement of the first area, the height measurement of the second area, and the height measurement of the third area all result in measurement errors.

10. 2. The inspection method according to claim 1, wherein the determining step determines that an unmeasurable area exists in the first area if only the result of height measurement of the first area is a measurement error.

11. a setting step of setting information on the shape of the mold; an inspection step of inspecting a state of a mold mounted on a mold holding unit according to the inspection method of any one of claims 1 to 10, and determining whether the state of the mold matches the information set in the setting step; a processing step of imprinting a material on a substrate using the mold when it is confirmed in the inspection step that the state of the mold matches the information set in the setting step; An imprint method comprising:

12. forming a pattern on a substrate according to the imprinting method of claim 11; processing the substrate on which the pattern is formed; and manufacturing an article from the processed substrate.

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