Imprinting device, imprinting method, and article manufacturing method

Abstract

To provide a technique advantageous in improving the accuracy of positioning between a shot area of a substrate and a mold.SOLUTION: An imprint device executes, for a plurality of shot areas of a substrate, imprint processing of transferring a pattern of a mold to an imprint material arranged on the substrate. The imprint device comprises: a detector that detects first marks provided on the substrate and second marks provided on the mold; and a control unit that controls the positioning of the detector based on a drive amount stored in a storage unit by which the detector should be driven to bring the first marks and the second marks within a specific area of the visual field of the detector, and a correction value stored in the storage unit for correcting the drive amount and according to the relative positions of the first marks. The control unit performs alignment between a shot area selected from the plurality of shot areas and the mold based on output from the detector, and updates the correction value held in the storage unit based on the output from the detector.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] An imprint apparatus can be used in a lithography process for manufacturing articles such as magnetic storage media and semiconductor devices. In the imprint apparatus, a mold is brought into contact with an imprint material disposed on a shot region of a substrate, and the imprint material is cured, whereby the pattern of the mold is transferred onto the shot region of the substrate. For example, in the manufacture of semiconductor devices, the accuracy of aligning a circuit pattern to be newly formed with respect to a circuit pattern already formed on a substrate (alignment accuracy) is important. In the imprint apparatus, a die-to-die alignment method is adopted as an alignment method between the shot region of the substrate and the mold. The die-to-die alignment method is a method of optically detecting the relative position between a substrate-side mark and a mold-side mark for each shot region of the substrate and aligning the shot region and the mold.

[0003] Patent Document 1 describes correcting the relative position between a second shot region and a mold before bringing the imprint material on the second shot region into contact with the mold based on the amount of misalignment between the first shot region and the mold when an imprint process is performed on the first shot region.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In die bonder alignment, the shot area on the substrate and the mold are aligned by detecting, with a detector, the relative positions between the marks provided in the shot area of the substrate and the marks provided in the mold. Here, since the aberration of the optical system of the detector and the influence of uneven illumination of the marks can vary depending on the position within the field of view of the detector, the detection error by the detector can vary depending on the position of the marks within the field of view of the detector.

[0006] An object of the present invention is to provide a technology advantageous for improving the alignment accuracy between the shot area on the substrate and the mold.

Means for Solving the Problems

[0007] One aspect of the present invention relates to an imprint apparatus that performs an imprint process for transferring a pattern of a mold to an imprint material disposed on a substrate for a plurality of shot regions of the substrate. The imprint apparatus includes a detector for detecting a first mark provided on the substrate and a second mark provided on the mold, a first driving amount for driving the detector to accommodate the first mark and the second mark within a specific region of the field of view of the detector, and a control unit for controlling the positioning of the detector based on a second driving amount based on the first driving amount and a correction value for correcting the first driving amount. The first driving amount and the correction value are held in a storage unit. The control unit drives the detector based on the second driving amount, aligns a shot region selected from the plurality of shot regions with the mold based on an output of the detector, and updates the correction value held in the storage unit based on the output of the detector when the alignment is performed.

Effects of the Invention

[0008] According to the present invention, a technology advantageous for improving the alignment accuracy between the shot area on the substrate and the mold is provided.

Brief Description of the Drawings

[0009]

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Modes for Carrying Out 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 invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system in which the direction parallel to the surface of the substrate is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X-direction, Y-direction, and Z-direction, respectively, and the rotations around the X-axis, Y-axis, and Z-axis are θX, θY, and θZ, respectively. The control or drive with respect to the X-axis, Y-axis, and Z-axis means the control or drive with respect to the direction parallel to the X-axis, the direction parallel to the Y-axis, and the direction parallel to the Z-axis, respectively. Further, the control or drive with respect to the θX-axis, θY-axis, and θZ-axis means the control or drive with respect to the rotation around the axis parallel to the X-axis, the rotation around the axis parallel to the Y-axis, and the rotation around the axis parallel to the Z-axis, respectively. Also, the position is information that can be specified based on the coordinates of the X-axis, Y-axis, and Z-axis, and the orientation is information that can be specified by the values of the θX-axis, θY-axis, and θZ-axis. Positioning means controlling the position and / or orientation. Alignment may include controlling the position and / or orientation of at least one of the substrate and the mold so that the alignment error (overlay error) between the shot region of the substrate and the pattern region of the mold is reduced. Further, alignment may include control for correcting or changing the shape of at least one of the shot region of the substrate and the pattern region of the mold.

[0012] FIG. 1 schematically and exemplarily shows the configuration of an imprint apparatus NIL according to an embodiment. The imprint apparatus NIL can be configured to perform an imprint process for transferring the pattern of a mold 11 onto an imprint material disposed on a substrate 1 for a plurality of shot regions of the substrate 1. As the imprint material, a curable composition (which may also be referred to as an uncured resin) that cures when energy for curing is applied is used. As the energy for curing, electromagnetic waves, heat, etc. can be used. The electromagnetic waves can be, for example, light selected from the range of wavelengths of 10 nm or more and 1 mm or less, such as infrared rays, visible light, ultraviolet rays, etc. The curable composition can be a composition that cures by irradiation with light or by heating. Among these, the photocurable composition that cures by irradiation with light contains at least a polymerizable compound and a photoinitiator, and may further contain a non-polymerizable compound or a solvent as necessary. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, a polymer component, etc. The imprint material can be disposed on the substrate in a droplet shape, or in an island shape or a film shape formed by connecting a plurality of droplets. Also, the imprint material may be supplied onto the substrate in a film shape by a spin coater or a slit coater. The viscosity of the imprint material (viscosity at 25°C) can be, for example, 1 mPa·s or more and 100 mPa·s or less. As the material of the substrate, for example, glass, ceramics, metal, semiconductor (Si, GaN, SiC, etc.), resin, etc. can be used. If necessary, a member made of a material different from that of the substrate may be provided on the surface of the substrate. The substrate is, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass.

[0013] The mold 11 has a pattern region on the surface facing the substrate 1, and the pattern region has a pattern such as a circuit pattern. The pattern may be understood to be constituted by a recessed portion recessed with respect to a reference plane, or may be understood to be constituted by a protruding portion protruding from the reference plane. The material of the mold 11 is a material that can transmit light such as ultraviolet rays as energy for curing, such as quartz.

[0014] The imprint apparatus NIL may include a substrate operation mechanism 2, a mold operation mechanism 13, a curing unit 41, one or more detectors (scopes) 14, a dispenser 21, and a control unit 40. The substrate operation mechanism 2 may include a substrate holding unit that holds the substrate 1 and a substrate drive mechanism that positions the substrate 1 by driving the substrate holding unit. The substrate operation mechanism 2 may be configured to drive the substrate 1 in a plurality of axes (for example, three axes of X-axis, Y-axis, and θZ-axis, preferably six axes of X-axis, Y-axis, Z-axis, θX-axis, θY-axis, and θZ-axis). The substrate holding unit may hold the substrate 1 by a holding method such as vacuum suction or electrostatic suction. The substrate drive mechanism may drive the substrate holding unit along the surface plate 3. The surface plate 3 may be supported by the mount 4, whereby vibrations transmitted from the floor to the surface plate 3 can be reduced.

[0015] The mold operation mechanism 13 may include a mold holding unit that holds the mold 11 and a mold operation mechanism that positions the mold 11 by driving the mold holding unit. The mold operation mechanism 13 may be configured to drive the mold 11 in a plurality of axes (for example, three axes of Z-axis, θX-axis, and θY-axis, preferably six axes of X-axis, Y-axis, Z-axis, θX-axis, θY-axis, and θZ-axis). The substrate operation mechanism 2 and the mold operation mechanism 13 constitute a relative drive mechanism that drives at least one of the substrate 1 and the mold 11 so that the relative positions of the substrate 1 and the mold 11 are adjusted. The adjustment of the relative position by the relative drive mechanism includes driving for the contact of the mold 11 with the imprint material on the substrate 1 and the separation of the mold 11 from the cured imprint material (pattern of the cured product). Further, the adjustment of the relative position by the relative drive mechanism includes the alignment of the substrate 1 (shot region) and the mold 11 (pattern region). The mold operation mechanism 13 may include a deformation mechanism 12 that deforms the mold 11 or the pattern region of the mold 11. The deformation of the mold 11 or the pattern region of the mold 11 by the deformation mechanism 12 may contribute to improving the alignment accuracy between the shot region of the substrate 1 and the pattern region of the mold 11.

[0016] The curing unit 41 cures the imprint material by irradiating the imprint material disposed or filled in the space between the shot area of the substrate 1 and the pattern area of the mold 11 with energy for curing (for example, light energy). The curing unit 41 may include a mirror 42 that deflects or bends the energy for curing. Further, the curing unit 41 may include one or more other optical elements.

[0017] Each detector 14 can be used to detect a mark provided on the substrate 1 (shot area) (this is also referred to as the first mark for convenience) and a mark provided on the mold 11 (this is also referred to as the second mark for convenience). For example, the detector 14 can be used to detect the relative position between the first mark provided in the shot area of the substrate 1 and the second mark provided on the mold 11. Alternatively, the detector 14 can be used to detect the position of at least one of the first mark provided in the shot area of the substrate 1 and the second mark provided on the mold 11 (for example, the position within the field of view of the detector 14).

[0018] The detector 14 can be referred to as an alignment scope, for example. The detector 14 can include an imaging element (for example, an image sensor such as a CCD sensor or a MOS sensor), an optical system that forms images of the first mark and the second mark on the imaging surface of the imaging element, and an illuminator that irradiates the first mark and the second mark with measurement light 63. The images formed on the imaging surface may be images formed individually by each of the first mark and the second mark, or may be moiré images or interference fringes formed by the first mark and the second mark when the mold and the substrate are in contact via the imprint material. At least one of the first mark and the second mark may be a part of the circuit pattern.

[0019] The imprint apparatus NIL may include a plurality of drive mechanisms 70 that individually drive and position a plurality of detectors 14. Each drive mechanism 70 can drive the detector 14 so that the first mark and the second mark constituting the mark pair are within a specific region of the field of view of the detector 14. Such an operation can be controlled by the control unit 40. The specific region of the field of view of the detector 14 can be, for example, the central region of the field of view. The central region is a region centered on the center of the field of view and can have an area that is 50% or less, 40% or less, 30% or less, 20% or less, or 10% or less of the area of the field of view.

[0020] The imprint apparatus NIL may include an optical system such as a relay optical system 64 between the mold 11 or the mold operating mechanism 13 and one or more detectors 14, and at least a part of the optical system may be shared with, for example, the curing unit 41. The relay optical system 64 can include, for example, one or more lenses 61 and one or more mirrors 62. The relay optical system 64 may be an equi-magnification system or a magnification system. The relay optical system 64 can include, for example, two lenses 61 and two mirrors 62, but is not limited thereto. Also, the relay optical system 64 is preferably a telecentric optical system. In this specification, the detector 14 means a part that is driven and positioned by the drive mechanism 70, and the relay optical system 64 is described as a component different from the detector 14. The configuration including the detector 14 and the relay optical system 64 can be understood as a detection system.

[0021] The dispenser 21 is configured to supply or dispose the imprint material 22 onto the shot region of the substrate 1. The dispenser 21 is an optional component, and may not be provided when the imprint material is disposed on the substrate 1 by a dispenser outside the imprint apparatus NIL. The type of the imprint material 22 can be appropriately selected according to the type of the article such as the semiconductor device to be manufactured. Depending on the type of the imprint material 22, the energy (e.g., wavelength) for curing irradiated to the imprint material 22 by the curing unit 41 can also be changed.

[0022] The imprint apparatus NIL may further include an alignment measuring instrument 31 for positioning the substrate 1, and a transfer system for loading the mold 11 and the substrate 1 into a chamber (not shown) of the imprint apparatus 1 and unloading them from the chamber. The alignment measuring instrument 31 can detect, for example, the positional deviation of the substrate 1 in the X and Y directions. The above transfer system may include a mold transfer mechanism (not shown) for loading and unloading the mold 11 and a substrate transfer mechanism for loading and unloading the substrate 1. The mold transfer mechanism has a transfer robot and can transfer the mold 11 between a mold stocker arranged at a predetermined position and the mold operating mechanism 13. The mold stocker can be a carrier for storing a plurality of molds 11. The substrate transfer mechanism 51 can transfer the substrate 1 between a substrate carrier (not shown) that can be arranged at a predetermined substrate loading port by a transfer robot and the substrate holding portion of the substrate operating mechanism 2.

[0023] The control unit 40 controls the above components of the imprint apparatus NIL and can define the operation of the imprint apparatus NIL based on information stored in a storage unit MEM such as a memory. The storage unit MEM may be provided inside the control unit 40 or outside the control unit 40. The control unit 40 can be constituted by, for example, a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), or an ASIC (abbreviation for Application Specific Integrated Circuit), or a general-purpose or dedicated computer in which a program is incorporated, or a combination of all or part of these.

[0024] Hereinafter, the operation of the imprint apparatus NIL will be exemplarily described. This operation is controlled by the control unit 40. The control unit 40 can control the substrate transfer mechanism 51 so that the substrates 1 constituting a lot are transferred from the substrate carrier to the substrate holding portion of the substrate operating mechanism 2. Further, the control unit 40 can control the mold transfer mechanism so that the mold 11 specified by control information (processing recipe) for controlling the processing of the lot is transferred from the mold stocker to the mold holding portion of the mold operating mechanism 13.

[0025] Next, the control unit 40 can perform pre-alignment measurement to measure the relative positions of the type 11 and the shot regions of the substrate 1. Specifically, the control unit 40 can measure the positions of the substrate 1 and the type 11 respectively with reference to the coordinates of the imprint apparatus NIL by using the alignment measuring instrument 31 and the detector 14. Here, the control unit 40 can drive the detector 14 in the drive mechanism 70 so that the second mark selected from the plurality of second marks provided on the type 11 enters the field of view of the detector 14. Then, as schematically shown in Fig. 2(a), the position of the second mark 72 of the type 11 can be measured or detected with reference to the position of the detector 14. On the other hand, while controlling the substrate operation mechanism 2 so that the plurality of first marks provided on the substrate 1 sequentially enter the field of view of the alignment measuring instrument 31, the control unit 40 can measure or detect the positions of the respective first marks by using the alignment measuring instrument 31. Thereby, the positions of the plurality of shot regions of the substrate 1 can be measured or detected with reference to the position of the substrate operation mechanism 2.

[0026] Next, the control unit 40 can control the substrate operation mechanism 2 and the dispenser 21 so that an imprint material is disposed on the shot region of the substrate 1 where the imprint process is to be executed among the plurality of shot regions. Then, the control unit 40 can control the substrate operation mechanism 2 so that the shot region is positioned under the type 11. Next, the control unit 40 can control the type operation mechanism 13 so that the imprint material on the shot region comes into contact with the pattern region of the type 11. Thereby, the imprint material on the shot region can be filled in the space (including the pattern of the pattern region) between the shot region and the pattern region of the type 11. Further, the control unit 40 can drive the plurality of detectors 14 in the plurality of drive mechanisms 70 so that the second mark to be detected is disposed in a specific region within the field of view of each of the one or more detectors 14, typically the plurality of detectors 14.

[0027] Next, the control unit 40 can align the shot area of the substrate 1 and the pattern area of the mold 11 based on the detection results of the plurality of detectors 14. Such alignment is called die-to-die alignment. At this time, the control unit 40 may deform the mold 11 or the pattern area by the deformation mechanism 12.

[0028] Next, the control unit 40 can control the curing unit 41 so that energy for curing is irradiated onto the imprint material on the shot area of the substrate 1 through the mold 11. As a result, the imprint material on the shot area of the substrate 1 is cured, and a pattern made of a cured product of the imprint material can be formed. Next, the control unit 40 can control the mold operation mechanism 13 so that the mold 11 is separated from the cured product of the imprint material on the shot area of the substrate 1. As a result, a cured pattern in which the pattern of the pattern area of the mold 11 is transferred can remain on the shot area of the substrate 1. The control unit 40 repeats the above processes for the remaining shot areas of the substrate 1, so that patterns made of cured products of the imprint material can be formed in all the shot areas of the substrate 1. pattern.

[0029] Four mark pairs MP are shown in FIG. 3. Each mark pair MP is composed of a first mark provided in the shot area of the substrate 1 and a second mark provided in the mold 11. With reference to FIG. 3, the driving of the detector 14 by the driving mechanism 70 in the operation of accommodating the mark pair MP, that is, the first mark provided on the substrate 1 and the second mark provided on the mold 11, within a specific area of the field of view of the detector 14 will be described. In FIG. 3, the shot area of the substrate 1 and the pattern area of the mold 11 are shown as area 91. Also, in FIG. 3, the mark pair composed of the first mark provided on the substrate 1 and the second mark provided on the mold 11 is shown as the mark pair MP. The mark pair MP can be understood as representing the first mark or as representing the second mark.

[0030] The mold 11 can be held by the mold holding part of the mold manipulation mechanism 13 so that the center of the pattern area of the mold 11 substantially coincides with the origin O(0, 0) of the imprint apparatus NIL. Also, the substrate 1 can be aligned by the substrate manipulation mechanism 2 so that the center of the shot area where the imprint process is to be performed immediately among the plurality of shot areas substantially coincides with the origin O(0, 0) of the imprint apparatus NIL. Thereby, the center of the shot area of the substrate 1 and the center of the pattern area of the mold 11 substantially coincide with the origin O(0, 0) of the imprint apparatus NIL.

[0031] For a plurality of mark pairs MP with respect to the center of the shot area of the substrate 1 or the pattern area of the mold 11, here, the relative positions of the positions of the first to fourth mark pairs MP are set as (Δx1, Δy1), (Δx2, Δy2), (Δx3, Δy3), (Δx4, Δy4). In order to accommodate each mark pair MP within a specific area of the field of view of the corresponding detector 14 among the four detectors 14, the driving amounts when moving the four detectors 14 from their respective home positions are set as (Mx1, My1), (Mx2, My2), (Mx3, y3), (Mx4, My4). The driving amounts (Mx1, My1), (Mx2, My2), (Mx3, y3), (Mx4, My4) are expressed, for example, as in the following formula (1).

[0032] (Mx1, My1) = (Δx1, Δy1) - (SPx1, SPy1) (Mx2, My2) = (Δx2, Δy2) - (SPx2, SPy2) (Mx3, My3) = (Δx3, Δy3) - (SPx3, SPy3) (Mx4, My4) = (Δx4, Δy4) - (SPx4, SPy4) ··· Formula (1) Here, (SPx1, SPy1), (SPx2, SPy2), (SPx3, SPy3), (SPx3, SPy3), (SPx4, SPy4) are the coordinates of the home positions of the first to fourth detectors 14, respectively. The control unit 40 can obtain (Δx1, Δy1), (Δx2, Δy2), (Δx3, Δy3), (Δx4, Δy4) from, for example, control information (processing recipe) for controlling the processing for a lot. Here, when error factors can be ignored, by driving the first to fourth detectors 14 according to the driving amounts (Mx1, My1), (Mx2, My2), (Mx3, y3), (Mx4, My4), the mark pair MP can be placed within a specific region of their fields of view. However, in reality, aberration of the relay optical system 64, characteristic changes due to heat, etc., driving errors by the driving mechanism 70, uneven illumination of the measurement light 63 of the detector 14, etc. can be error factors. Therefore, it is difficult to place the mark pair MP within a specific region of their fields of view only by driving the first to fourth detectors 14 according to the driving amounts (Mx1, My1), (Mx2, My2), (Mx3, y3), (Mx4, My4).

[0033] As schematically shown in FIGS. 2(a) to 2(d), the relative position of the mark pair MP (the first mark 71 and the second mark 72) in the field of view 81 of the detector 14 can change according to the relative position between the detector 14 and the mark pair MP. When the relative position of the mark pair MP in the field of view 81 changes, the appearance of the mark pair MP (such as the shape of the mark or mark pair in the detection image) can change due to the aberration of the relay optical system 64 and uneven illumination of the measurement light 63. The detection result of the relative position between the first mark 71 and the second mark 72 obtained by image processing of the detection image of the mark pair MP by the detector 14 can also change according to the relative position of the mark pair MP in the field of view 81.

[0034] In the relative position between the mark pair MP and the detector 14 as shown in Fig. 2(a), as shown in Fig. 2(b), the mark pair MP is within the central region of the field of view 81 of the detector 14. On the other hand, in the relative position between the mark pair MP and the detector 14 as shown in Fig. 2(c), as shown in Fig. 2(d), the mark pair MP does not fit within the central region of the field of view 81 of the detector 14. In Figs. 2(b) and 2(d), the detection accuracy of the relative position between the first mark 71 and the second mark 72 is different. Specifically, the detection accuracy in Fig. 2(b) is higher.

[0035] In the alignment by the divider alignment, the measurement error of the relative position between the first mark 71 provided in the shot region of the substrate 1 and the second mark 72 provided in the mold 11 affects the alignment accuracy. Therefore, it is preferable to always detect the relative position between the first mark 71 and the second mark 72 in a state where the mark pair MP is within a specific region (preferably the central region) in the field of view 81 of the detector 14, whereby the measurement error can be kept within a certain value.

[0036] However, heat may be generated in the optical elements of the relay optical system 64, such as the lens 61 and the mirror 62, by the measurement light 63 used by the detector 14. As a result, the optical characteristics of the relay optical system 64 change, and this change in the optical characteristics may cause a change in the relative position of the mark pair MP in the field of view 81 of the detector 14. Also, due to the driving error of the detector 14 by the driving mechanism 70, the relative position of the mark pair MP in the field of view 81 of the detector 14 may change.

[0037] Also, as illustrated in Fig. 4, problems may occur even when a plurality of second marks 72 (in other words, mark pairs MP) in the pattern region 92 of the mold 11 are selectively used for detecting the alignment error between the shot region and the pattern region 92. Specifically, the amount of heat held for each of the plurality of second marks 72 (mark pairs MP) may be different. Therefore, depending on the mark pair MP in the shot region or the pattern region 92, the amount of deviation of the relative position of the mark pair MP in the field of view 81 of the detector 14 may change.

[0038] Therefore, in this embodiment, when the control unit 40 moves the four detectors 14 from their respective home positions to the target coordinate positions (target positions) according to Equation (2) instead of Equation (1), it determines the driving amounts (M’x1, M’y1), (M’x2, M’y2), (M’x3, M’y3), and (M’x4, M’y4).

[0039] (M’x1, M’y1) = (Mx1, My1) + (Cx1, Cy1) (M’x2, M’y2) = (Mx2, My2) + (Cx2, Cy2) (M’x3, M’y3) = (Mx3, My3) + (Cx3, Cy3) (M’x4, M’y4) = (Mx4, My4) + (Cx4, Cy4) ··· Equation (2) Here, (Mx1, My1) is the driving amount by which the detector 14 should be driven to fit the first mark pair (the first mark and the second mark) selected from a plurality of mark pairs used for measuring the alignment error within a specific region of the field of view of the detector 14 that measures it. Similarly, (Mx2, My2) is the driving amount by which the detector 14 should be driven to fit the second mark pair (the first mark and the second mark) selected from a plurality of mark pairs used for measuring the alignment error within a specific region of the field of view of the detector 14 that measures it. Similarly, (Mx3, My3) is the driving amount by which the detector 14 should be driven to fit the third mark pair (the first mark and the second mark) selected from a plurality of mark pairs used for measuring the alignment error within a specific region of the field of view of the detector 14 that measures it. Similarly, (Mx4, My4) is the driving amount by which the detector 14 should be driven to fit the 42 mark pairs (the first mark and the second mark) selected from a plurality of mark pairs used for measuring the alignment error within a specific region of the field of view of the detector 14 that measures it.

[0040] Also, (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), and (Cx4, Cy4) are correction values corresponding to the relative positions of the first mark 71 in the shot region (or the second mark 72 in the pattern region). Equation (2) may be transformed into the following Equation (3) using Equation (1).

[0041] (M’x1, M’y1) = (Δx1, Δy1) - (SPx1, SPy1) + (Cx1, Cy1) (M’x2, M’y2) = (Δx2, Δy2) - (SPx2, SPy2) + (Cx2, Cy2) (M’x3, M’y3) = (Δx3, Δy3) - (SPx3, SPy3) + (Cx3, Cy3) (M’x4, M’y4) = (Δx4, Δy4) - (SPx4, SPy4) + (Cx4, Cy4) ··· Equation (3) In FIG. 5, the driving amounts (Mx1, My1), (Mx2, My2), (Mx3, y3), and (Mx4, My4) are illustrated as the driving amounts M before correction. Also, in FIG. 5, the driving amounts (M’x1, M’y1), (M’x2, M’y2), (M’x3, M’y3), and (M’x4, M’y4) are illustrated as the driving amounts M’ after correction. Further, in FIG. 5, the correction values (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), and (Cx4, Cy4) are illustrated as the correction values C. Also, the following explanations will follow such a notation method.

[0042] FIG. 6 shows the flow of the process of forming a pattern on a plurality of shot regions of the substrate 1 in the imprint apparatus NIL. The process shown in FIG. 6 is controlled by the control unit 40. In step S100, the control unit 40 controls the substrate operation mechanism 2 and the dispenser 21 so that an imprint material is disposed on a shot region (hereinafter, the selected shot region) selected from the plurality of shot regions. In step S101, the control unit 40 controls the substrate operation mechanism 2 so that the selected shot region is positioned under the mold 11 for the imprint process on the selected shot region from the plurality of shot regions.

[0043] In step S102, the control unit 40 determines a plurality of driving amounts M' for driving the plurality of detectors 14 according to Equation (2) or Equation (3) based on the driving amount M and the correction amount C held in the storage unit MEM. Note that M' = M + C. Here, the correction value C held in the storage unit MEM is updated in a later-described step S105. Therefore, when the updated correction value C is held in the storage unit MEM, the control unit 40 can determine the driving amount M' based on the driving amount M and the updated correction value C. Typically, the plurality of driving amounts M' are different from each other, and the plurality of correction values C are different from each other. In step S103, the control unit 40 controls the plurality of driving mechanisms 70 to drive the plurality of detectors 14 according to the plurality of driving amounts M' determined in step S102. Here, if the plurality of correction values C for determining the plurality of driving amounts M' respectively are appropriate, by this driving, the mark pairs corresponding to the specific regions within the respective fields of view of the plurality of detectors 14 will fit. Note that when performing imprint processing on a plurality of shot regions continuously, the control unit 40 may move the detector 14 to a position determined by the driving amount M' for the next shot region without returning the detector 14 to the home position. At this time, if the correction value C is the same as the value at the time of processing the previous shot region, since the position of the detector 14 is also the same as that at the time of processing the previous shot region, the detector 14 may not need to move.

[0044] In step S103, the control unit 40 executes imprint processing. The imprint processing may include a contact step, an alignment step, a filling step, a curing step, and a separation step. In the contact step, the control unit 40 controls the mold operation mechanism 13 so that the pattern region of the mold 11 contacts the imprint material above the selected shot region. Thereby, the filling of the imprint material into the space between the selected shot region and the pattern region is started. In parallel with the filling of the imprint material, the alignment step is executed.

[0045] In the alignment process, the control unit 40 performs alignment between the selected shot area and the mold based on the outputs of the plurality of detectors 14. Specifically, in the alignment process, the control unit 40 uses the plurality of detectors 14 to detect the relative positions of the first mark and the second mark in the plurality of mark pairs, and detects the alignment error between the selected shot area and the pattern area of the mold 11 based on those results. Also, in the alignment process, the control unit 40 executes the alignment between the selected shot area and the pattern area of the mold 11 while controlling at least one of the substrate manipulation mechanism 2 and the mold manipulation mechanism 13 so that the alignment error falls within the allowable range. The detection of the alignment error and the alignment based thereon can be repeated multiple times or executed continuously. In the curing process, the control unit 40 controls the curing unit 41 so that the imprint material is irradiated with energy for curing between the selected shot area and the pattern area of the mold 11. In the separation process, the control unit 40 controls the mold manipulation mechanism 13 so that the pattern area of the mold 11 is separated from the cured imprint material on the selected shot area.

[0046] In step S105, the control unit 40 can update the correction values (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), (Cx4, Cy4) held in the storage unit MEM based on the output of the detector 14 in the imprint process for the selected shot area. This correction value is, for example, the deviation amount between the center position of the field of view of the detector 14 at the time of alignment and the representative position of the mark pair. For example, the control unit 40 can update the correction values (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), (Cx4, Cy4) based on the amount and direction of the change in the representative position of the mark pair due to the execution of the alignment process. The representative position of the mark pair is, for example, the average position between the center position of the first mark and the center position of the second mark. Alternatively, the control unit 40 can update the correction values (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), (Cx4, Cy4) based on the amount and direction of the change in the position of the first mark due to the execution of the alignment process. Alternatively, the control unit 40 can update the correction values (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), (Cx4, Cy4) based on the amount and direction of the change in the position of the second mark due to the execution of the alignment process. The correction values (Cx1, Cy1), (Cx2, Cy2), (Cx3, Cy3), (Cx4, Cy4) can be used to execute the alignment process using a mark pair having the same relative position as the relative position of the mark pair within the shot area when updating this. As described above, the correction value can depend on, for example, the aberration of the detector 14 and / or the drive error of the drive mechanism 70 that drives the detector 14.

[0047] In step S106, the control unit 40 determines whether the imprint process for all the shot areas to be imprinted on the substrate has ended. If there is an unprocessed shot area, it returns to step S100 so that the imprint process for it is performed.

[0048] Here, among the plurality of detectors 14, there are individual differences, and the heat generated by the measurement light can also be different. Therefore, the correction value C in Equation (2) or Equation (3) may be managed in the storage unit for each individual detector 14.

[0049] Figs. 7(a) and 7(b) schematically show how imprinting is performed on a plurality of shot areas 101 of a substrate. Also shown in Figs. 7(a) and 7(b) are the positions of the first marks in the shot areas 101 indicated by symbols ○, ×, Δ, □, ◎, and ☆. Shot areas where Δ and □ do not exist are shot areas whose shapes are restricted by the outer edge of the substrate, so-called partial shot areas. When the imprinting process is executed in the order indicated by the arrows in Fig. 7(a), there are a plurality of shot areas 101 that perform alignment using mark pairs with the same relative positions in the shot area 101. For such a plurality of shot areas 101, for example, the driving amount M' can be determined using the correction value C updated in the process of the immediately preceding shot area.

[0050] Furthermore, correction values C may be managed using the storage unit MEM for each relative position in the shot area, such as the symbols ○, ×, Δ, □, ◎, and ☆. In Fig. 7(b), □ and ☆, and Δ and ◎ perform alignment operations by moving the same detector 14. However, when the position moves significantly like □ and ☆ even with the same detector 14, the position of the measurement light 63 passing through the relay optical system changes. Therefore, it is preferable to manage them as separate correction values for each relative position in the shot area. That is, when aligning ☆, the correction value for ☆ is used, and when aligning □, the correction value for □ is used to determine the driving amount M' and drive the detector 14. Thereby, even when performing imprinting on a partial shot area, the mark pair can be positioned within the central region of the field of view 81 of the detector 14, and the detection accuracy of alignment can be improved.

[0051] The pattern of the cured product formed using the imprinting apparatus is used permanently on at least a part of various articles, or temporarily when manufacturing various articles. Articles include electric circuit elements, optical elements, MEMS, recording elements, sensors, or molds, etc. As electric circuit elements Examples include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor devices such as LSI, CCD, image sensors, and FPGA. Examples of the mold include a mold for imprinting.

[0052] The pattern of the cured product is used as it is as at least a part of the constituent members of the above article, or is temporarily used as a resist mask. After etching, ion implantation, etc. are performed in the substrate processing step, the resist mask is removed.

[0053] Next, an article manufacturing method will be described in which a pattern is formed on a substrate by an imprint apparatus, the substrate on which the pattern is formed is processed, and an article is manufactured from the processed substrate. As shown in FIG. 8(a), a substrate 1z such as a silicon wafer having a workpiece 2z such as an insulator formed on its surface is prepared. Subsequently, an imprint material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. Here, a state where a plurality of droplet-shaped imprint materials 3z are applied on the substrate is shown.

[0054] As shown in FIG. 8(b), an imprint mold 4z is opposed with the side on which the concavo-convex pattern is formed facing the imprint material 3z on the substrate. As shown in FIG. 8(c), the substrate 1z to which the imprint material 3z is applied and the mold 4z are brought into contact with each other and pressure is applied. The imprint material 3z is filled in the gap between the mold 4z and the workpiece 2z. When light is irradiated through the mold 4z as energy for curing in this state, the imprint material 3z cures.

[0055] As shown in FIG. 8(d), after the imprint material 3z is cured and the mold 4z and the substrate 1z are separated, a pattern of the cured product of the imprint material 3z is formed on the substrate 1z. The pattern of this cured product has a shape in which the concave portion of the mold corresponds to the convex portion of the cured product and the convex portion of the mold corresponds to the concave portion of the cured product. That is, the concavo-convex pattern of the mold 4z is transferred to the imprint material 3z.

[0056] As shown in Fig. 8(e), when etching is performed using the cured product pattern as an etching mask, the portion of the surface of the workpiece 2z where the cured product is absent or remains thinly is removed, resulting in the groove 5z. As shown in Fig. 8(f), when the cured product pattern is removed, an article with the groove 5z formed on the surface of the workpiece 2z can be obtained. Here, the cured product pattern has been removed, but it may not be removed after processing and may be used, for example, as a film for interlayer insulation included in a semiconductor element or the like, that is, as a constituent member of the article.

[0057] The invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention.

Explanation of Reference Numerals

[0058] NIL: Imprint apparatus, 1: Substrate, 11: Mold, 14: Measuring instrument (scope), 40: Control unit

Claims

1. An imprint apparatus that performs an imprint process for transferring a pattern of a mold to an imprint material disposed on a substrate for a plurality of shot regions on the substrate, a detector for detecting a first mark provided on the substrate and a second mark provided on the mold, a control unit that controls the positioning of the detector by a second driving amount based on a first driving amount for driving the detector to accommodate the first mark and the second mark within a specific region of the field of view of the detector, and a correction value for correcting the first driving amount, wherein the first driving amount and the correction value are held in a storage unit, and the control unit drives the detector based on the second driving amount, aligns a shot region selected from the plurality of shot regions with the mold based on an output of the detector, and updates the correction value held in the storage unit based on the output of the detector when the alignment is performed. The imprint apparatus is characterized by this.

2. The alignment is performed by detecting, with the detector, a moire image or interference fringes formed by the first mark and the second mark when the mold and the substrate are in contact via the imprint material. The imprint apparatus according to claim 1, characterized by this.

3. The correction value is held in the storage unit for each relative position of the first mark in the shot region. The imprint apparatus according to claim 1 or 2, characterized by this.

4. The correction value is a deviation amount between a center position of the field of view of the detector and a representative position determined by the first mark and the second mark at the time of alignment. The imprint apparatus according to any one of claims 1 to 3, characterized by this.

5. The correction value depends on an aberration of the detector. The imprint apparatus according to any one of claims 1 to 4, characterized by this.

6. The correction value depends on a driving error of a driving mechanism that drives the detector. The imprint apparatus according to any one of claims 1 to 5, characterized by this.

7. The specific region is a central region of the field of view. The imprint apparatus according to any one of claims 1 to 6, characterized by this.

8. When there is an updated correction value as the correction value, the control unit controls the positioning of the detector based on the first driving amount and the updated correction value. The imprint apparatus according to any one of claims 1 to 7, characterized in that.

9. Comprising a plurality of detectors including the detector, On the substrate, a plurality of first marks including the first mark are provided, on the mold, a plurality of second marks including the second mark are provided, and each of the plurality of second marks corresponds to one of the plurality of first marks. Each of the plurality of detectors detects the relative position between one of the plurality of first marks and one of the plurality of second marks. The storage unit holds a plurality of first driving amounts including the first driving amount and a plurality of correction values including the correction value so as to correspond to each of the plurality of first marks. The imprint apparatus according to any one of claims 1 to 8, characterized in that.

10. The plurality of first driving amounts are different from each other, and the plurality of correction values are different from each other. The imprint apparatus according to claim 9, characterized in that.

11. The control unit aligns the selected shot area and the mold based on the relative position between the first mark and the second mark obtained based on the output of the detector, and updates the correction value based on at least one of the positions of the first mark and the second mark in the field of view of the detector driven according to the first driving amount. The imprint apparatus according to any one of claims 1 to 10, characterized in that.

12. An imprint method for performing an imprint process of transferring a pattern of a mold to an imprint material disposed on a substrate for a plurality of shot areas of the substrate, wherein a first driving amount for driving the detector to accommodate a first mark provided in a shot area selected from the plurality of shot areas and a second mark provided in the mold within a specific area of the field of view of the detector, and a correction value for correcting the first driving amount are held in a storage unit. The imprint method includes: A step of controlling the positioning of the detector by a second driving amount based on the first driving amount and the correction value. A step of performing imprinting on the selected shot area while aligning the shot area selected from a plurality of shot areas of the substrate with the mold based on the output of the detector; A step of updating the correction value held in the storage unit based on the output of the detector when the alignment is performed; An imprint method characterized by including the above.

13. A step of forming a pattern on a substrate using the imprint apparatus according to any one of Claims 1 to 11; A step of processing the substrate on which the pattern is formed to obtain an article; An article manufacturing method characterized by including the above.

14. An imprint apparatus that performs an imprint process for transferring a pattern of a mold to an imprint material disposed on a substrate for a plurality of shot areas of the substrate, A detector for detecting a first mark provided on the substrate and a second mark provided on the mold; A control unit that controls the positioning of the detector based on a target position for moving the detector to accommodate the first mark and the second mark within a specific area of the field of view of the detector, which is held in a storage unit, and a correction value for correcting the target position, which is held in the storage unit; The control unit aligns a shot area selected from the plurality of shot areas with the mold based on the output of the detector positioned based on the target position and the correction value, and updates the correction value held in the storage unit based on the output of the detector when the alignment is performed. An imprint apparatus characterized by the above.

15. An imprint method for performing an imprint process for transferring a pattern of a mold to an imprint material disposed on a substrate for a plurality of shot areas of the substrate, A step of controlling the positioning of the detector based on a target position for moving the detector to accommodate a first mark provided on a shot area selected from the plurality of shot areas and a second mark provided on the mold within a specific area of the field of view of the detector, which is held in a storage unit, and a correction value for correcting the target position, which is held in the storage unit; Based on the output of the detector positioned based on the target position and the correction value, performing the imprint process on the selected shot area while aligning the shot area selected from the plurality of shot areas with the mold; Updating the correction value held in the storage unit based on the output of the detector when the alignment is performed; An imprint method characterized by including the above.

Images