Method and system for forming a partial field

Abstract

The imprint method includes reducing the distance between the template and the substrate. [Solution] The method includes the steps of controlling the state of one or more of the template and the substrate while reducing the distance, and detecting the light intensity of the light reflected from both the template and the substrate. The method further includes the steps of determining whether predetermined light conditions are met based on the detected light intensity, determining an estimated initial contact point between the template and the substrate based on the detected light intensity if it is determined that the predetermined light conditions are met, and changing the state based on the difference if the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold.

Description

[Technical Field]

[0001] This disclosure relates to photomechanical molding systems (e.g., nanoimprint lithography and inkjet adaptive planarization). In particular, this disclosure relates to methods for imprinting (also called molding) full fields, partial fields, and small partial fields onto a substrate. [Background technology]

[0002] Nanofabrication involves the fabrication of extremely small structures with features on the order of 100 nanometers or less. One application where nanofabrication has had a significant impact is the fabrication of integrated circuits. The semiconductor processing industry continues to strive for greater production yields while increasing the amount of circuitry per unit area formed on a substrate. Improvements in nanofabrication include providing greater process control and / or improving throughput, as well as enabling a continuous reduction in the minimum feature dimensions of the structures formed.

[0003] One nanofabrication technique used today is commonly referred to as nanoimprint lithography. Nanoimprint lithography is useful in a variety of applications, including, for example, the fabrication of one or more layers of integrated devices by forming films on a substrate. Examples of integrated devices include, but are not limited to, CMOS logic, microprocessors, NAND flash memory, NOR flash memory, DRAM memory, MRAM, 3D crosspoint memory, Re-RAM, Fe-RAM, STT-RAM, and MEMS. Exemplary nanoimprint lithography systems and processes are described in detail in numerous publications, including U.S. Patents 8,349,241, 8,066,930, and 6,936,194. By this citation, all disclosures of these publications are incorporated herein.

[0004] The nanoimprint lithography techniques described in each of the above patents form a film on a substrate by forming a relief pattern on a moldable (polymerizable) layer. The shape of this film can then be used to transfer a pattern corresponding to the relief pattern into and / or onto the underlying substrate.

[0005] The molding process uses a template separated from the substrate. A moldable material is applied to the substrate. The template is brought into contact with the moldable material, which can be deposited as a droplet pattern using the moldable material, and the moldable material spreads and fills the space between the template and the substrate. The template can be used to imprint full fields and / or partial fields onto the substrate. The moldable material solidifies to form a film with a shape (pattern) that conforms to the molding surface of the template. After solidification, the template is separated from the solidified layer so that the template and the substrate are separated.

[0006] The substrate and solidified layer may then be subjected to known steps and processes for device (article) manufacturing, including, for example, curing, oxidation, layer formation, deposition, doping, planarization, etching, moldable material removal, dicing, bonding, and packaging. For example, the pattern on the solidified layer may be etched to transfer the pattern to the substrate.

[0007] In particular, achieving the target initial contact point can be difficult when imprinting partial fields. The target initial contact point is a predetermined location where the template first contacts the substrate to achieve optimal filling, low defect rate, and overlay performance. However, even when applying predetermined control parameters (described in more detail below) to attempt to achieve the target initial contact point, it has been found that the actual initial contact point may deviate by an amount that negatively impacts filling performance. Approaches based on models used in the past may become ineffective when there is large variation between wafers. Therefore, there is a need in the art for an imprinting method in which the actual initial contact point is closer to the target initial contact point in order to improve filling performance and product quality. [Overview of the project]

[0008] The imprint method includes the steps of: reducing the distance between a template and a substrate; controlling the state of one or more of the template and the substrate while the distance is being reduced; detecting the light intensity of light reflected from both the template and the substrate; determining whether predetermined light conditions are met based on the detected light intensity; if it is determined that the predetermined light conditions are met, determining an estimated initial contact point between the template and the substrate based on the detected light intensity; and, if the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, changing the state based on the difference.

[0009] A method for manufacturing an article includes the steps of: dispensing a moldable material onto a substrate; reducing the distance between a template and the substrate; controlling the state of one or more of the template and the substrate while the distance is being reduced; detecting the light intensity of light reflected from both the template and the substrate; determining whether predetermined light conditions are met based on the detected light intensity; if it is determined that the predetermined light conditions are met, determining an estimated initial contact point between the template and the substrate based on the detected light intensity; if the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, changing the state based on the difference; bringing the template into contact with the moldable material; exposing the moldable material beneath the template with a chemical beam; processing the substrate; and forming the article from the processed substrate.

[0010] The imprint system includes one or more memories and one or more processors, the one or more processors performing the steps of: reducing the distance between a template and the substrate; controlling the state of one or more of the template and the substrate while the distance is being reduced; detecting the light intensity of light reflected from both the template and the substrate; determining whether predetermined light conditions are met based on the detected light intensity; if it is determined that the predetermined light conditions are met, determining an estimated initial contact point between the template and the substrate based on the detected light intensity; and if the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, changing the state based on the difference.

[0011] These and other purposes, features, and advantages of this disclosure will become apparent upon reading the following detailed description of exemplary embodiments of this disclosure in conjunction with the accompanying drawings and the claims provided. [Brief explanation of the drawing]

[0012] To allow for a more detailed understanding of the features and advantages of the present invention, embodiments of the present invention can be described in more detail by referring to the embodiments shown in the accompanying drawings. However, it should be noted that the accompanying drawings only illustrate typical embodiments of the present invention and do not limit the scope of the present invention, and that other equally effective embodiments may also be permitted.

[0013] [Figure 1] Figure 1 shows an exemplary nanoimprint lithography system having a template with a mesa spaced apart from the substrate, as used in one embodiment.

[0014] [Figure 2A] Figure 2A is a diagram of an exemplary template that may be used in one embodiment. [Figure 2B] Figure 2B is a diagram of an exemplary template that may be used in one embodiment.

[0015] [Figure 3] Figure 3 is a flowchart showing an example of an imprint method used in one embodiment.

[0016] [Figure 4A] Figure 4A shows the layout of a field on a substrate used in one embodiment. [Figure 4B] Figure 4B shows the layout of a field on a substrate used in one embodiment.

[0017] [Figure 4C] Figure 4C shows a small partial field on a substrate used in one embodiment. [Figure 4D] Figure 4D shows a small partial field on a substrate used in one embodiment.

[0018] [Figure 5A]Figure 5A shows the state of the substrate and template as used in the embodiment. [Figure 5B] Figure 5B shows the state of the substrate and template as used in the embodiment. [Figure 5C] Figure 5C shows the state of the substrate and template as used in the embodiment. [Figure 5D] Figure 5D shows the state of the substrate and template as used in the embodiment. [Figure 5E] Figure 5E shows the state of the substrate and template as used in the embodiment. [Figure 5F] Figure 5F shows the state of the substrate and template as used in the embodiment.

[0019] [Figure 6] Figure 6 is a flowchart showing an exemplary embodiment of an imprint method.

[0020] [Figure 7] Figure 7 is a flowchart showing additional details of the imprint method shown in Figure 6.

[0021] [Figure 8A] Figure 8A shows a template and substrate diagram for imprinting a partial field at a certain distance.

[0022] [Figure 8B] Figure 8B shows images of the template and substrate when visible light is shone on the position shown in Figure 8A.

[0023] [Figure 9A] Figure 9A shows a template and substrate diagram for imprinting a partial field at a distance smaller than that shown in Figure 8A.

[0024] [Figure 9B]Figure 9B shows images of the template and substrate when visible light is shone on the position shown in Figure 9B.

[0025] [Figure 10A] Figure 10A shows a template and substrate diagram for imprinting a partial field at a distance smaller than that shown in Figure 9A.

[0026] [Figure 10B] Figure 10B shows images of the template and substrate when visible light is shone on the position shown in Figure 10A.

[0027] [Figure 11A] Figure 11A shows a template and substrate diagram for imprinting a partial field at a distance smaller than that shown in Figure 10A.

[0028] [Figure 11B] Figure 11B shows images of the template and substrate when visible light is shone on the position shown in Figure 11A.

[0029] [Figure 12A] Figure 12A shows a template and substrate diagram for imprinting a partial field at a distance smaller than that shown in Figure 11A.

[0030] [Figure 12B] Figure 12B shows images of the template and substrate when visible light is shone on the position shown in Figure 12A.

[0031] [Figure 13A] Figure 13A shows the image processing of the image in Figure 12B. [Figure 13B] Figure 13B shows the image processing of the image in Figure 12B.

[0032] [Figure 13C]Figure 13C shows the results of this image analysis process being performed for 6 frames as the template approaches the substrate.

[0033] [Figure 14] Figure 14 shows the frame statistics, which change with the frame number.

[0034] [Figure 15A] Figure 15A is a timing chart for executing the imprint method shown in Figure 3. [Figure 15B] Figure 15B is a timing chart for executing the imprint method shown in Figure 3.

[0035] Throughout the drawings, the same reference numerals and letters are used to indicate similar features, elements, components, or parts of the illustrated embodiments, unless otherwise noted. Furthermore, this disclosure is described in detail with reference to the drawings, but this is done in relation to exemplary embodiments. It is intended that changes and modifications may be made to the described exemplary embodiments without departing from the true scope and spirit of the disclosure of subject matter as defined by the appended claims. [Modes for carrying out the invention]

[0036] Nanoimprint lithography technology can be used in a step-and-repeat manner to form films on multiple fields on a substrate using a template. The patterning areas / forming surfaces (mesas) of the substrate and template can have different shapes and sizes. For example, the substrate may have areas to be patterned in a circular, elliptical, polygonal, or some other shape. Mesas, on the other hand, are typically smaller than the substrate and have a different shape. The substrate is divided into multiple full fields and multiple partial fields. All fields are the same size as the mesas; that is, the total surface area of ​​the mesa is equal to the area of ​​the full field. In other words, in the case of a full field, the entire forming surface overlaps with the substrate. Partial fields are fields on the edges of the substrate where the edges of the patterning areas on the substrate intersect with the patterning areas of the mesa. These fields can be divided into multiple categories based on their shape and / or area relative to the full field. In the case of a partial field, only a portion of the surface area of ​​the mesa is equal to the area of ​​the partial field. In other words, in the case of a partial field, the molded surface overlaps with the edge of the substrate.

[0037] Partial fields, which have an area smaller than the full field area (for example, the partial field area may be 5% to 99% of the full field area, or 10% to 95% of the full field area), tend to have a higher defect rate and / or longer processing time than full fields. In addition, small partial fields, which have an area of ​​50% or less of the full field area, or 35% or less of the full field area, are particularly difficult. That is, small partial fields have an area of ​​only 50% or less (or 35% or less) of the total surface area of ​​the mesa, i.e., 50% or less (or 35% or less) of the full field area. It is desirable to achieve lower defect rates and / or shorter processing times for partial fields and small partial fields. The applicant has found that by appropriately selecting the initial contact point (ICP), the defect rate and / or processing time for small partial fields can be reduced. One method of selecting an ICP is described in U.S. Patent No. 11,614,693.

[0038] However, even when the target ICP is appropriately selected, it has been found difficult to develop control parameters that achieve an actual ICP within the acceptable tolerance range from the target ICP, particularly for partial and small partial fields. What is needed is an imprint method that improves filling performance by making the actual ICP closer to the target ICP. Molding system

[0039] Figure 1 shows a molding system 100 (e.g., a nanoimprint lithography system or an inkjet adaptive planarization system) in which an embodiment may be implemented. The molding system 100 is used to manufacture an imprinted (molded) film on a substrate 102. The substrate 102 may be coupled to a substrate chuck 104. The substrate chuck 104 may be, but is not limited to, a vacuum chuck, a pin chuck, a grooved chuck, an electrostatic chuck, an electromagnetic chuck, and the like.

[0040] The substrate 102 and the substrate chuck 104 may be further supported by a substrate positioning stage 106. The substrate positioning stage 106 may provide translational and / or rotational motion along one or more of the position axes x, y, and z, and rotation axes θ, ψ, and φ. The substrate positioning stage 106, the substrate 102, and the substrate chuck 104 may also be positioned on a base (not shown). The substrate positioning stage may be part of a positioning system. In an alternative embodiment, the substrate chuck 104 may be mounted on the base.

[0041] Apart from the substrate 102 is a template 108 (also called a superstraight). The template 108 may include a body having a mesa (also called a mold) 110 extending toward the substrate 102 on the front end of the template 108. The mesa 110 may have a molding surface 112 on the front side of the template 108. The molding surface 112, also known as a patterning surface, is the surface of the template on which the moldable material 124 is molded. The mesa, more specifically the molding surface 112, has a surface area facing the substrate 102. In one embodiment, the molding surface 112 is flat and is used to flatten the moldable material. Alternatively, the template 108 may be formed without a mesa 110, in which case the surface of the template facing the substrate 102 is equal to the mesa 110, and the molding surface 112 is the surface of the template 108 facing the substrate 102.

[0042] The template 108 may be formed from, but is not limited to, materials such as fused silica, quartz, silicon, organic polymers, siloxane polymers, borosilicate glass, fluorocarbon polymers, metals, and hardened sapphire. The molded surface 112 may have features defined by a plurality of spaced template recesses 114 and / or template protrusions 116. The molded surface 112 defines the pattern that forms the basis of the pattern formed on the substrate 102. In another embodiment, the molded surface 112 is featureless, in which case a flat surface is formed on the substrate. In an alternative embodiment, the molded surface 112 is featureless, the same size as the substrate, and a flat surface is molded across the entire substrate.

[0043] The template 108 may be coupled to a template chuck 118. The template chuck 118 may be, but is not limited to, a vacuum chuck, a pin chuck, a groove chuck, an electrostatic chuck, an electromagnetic chuck, and / or other similar chuck types. The template chuck 118 may be configured to apply varying stress, pressure, and / or strain to the template 108. The template chuck 118 may include a template magnification control system 121. The template magnification control system 121 may include a piezo actuator (or other actuator) that can compress and / or stretch different parts of the template 108. The template chuck 118 may include a system such as a zone-based vacuum chuck, an actuator array, or a pressure bladder, which can apply a pressure difference to the back of the template to cause the template to bend and deform.

[0044] The template chuck 118 can be coupled to a molding head 120, which is part of a positioning system. The molding head 120 can be movably coupled to a bridge. The molding head 120 may include one or more actuators, such as a voice coil motor, a piezoelectric motor, a linear motor, a nut and screw motor, which are configured to move the template chuck 118 relative to the substrate in at least the z-axis direction and potentially in other directions (e.g., position axes x, y, and rotation axes θ, ψ, and φ).

[0045] The molding system 100 may further include a fluid dispenser 122. The fluid dispenser 122 may also be movably coupled to a bridge. In one embodiment, the fluid dispenser 122 and the molding head 120 share one or more or all of the positioning components. In an alternative embodiment, the fluid dispenser 122 and the molding head 120 move independently of each other. The fluid dispenser 122 may be used to deposit liquid moldable material 124 (e.g., polymerizable material) onto the substrate 102 in droplet patterns. Additional moldable material 124 may also be added to the substrate 102 using techniques such as droplet dispensing, spin coating, dip coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), thin film deposition, or thick film deposition before the moldable material 124 is deposited on the substrate 102. Depending on design considerations, the moldable material 124 may be dispensed onto the substrate 102 before and / or after a desired volume is defined between the molding surface 112 and the substrate 102. The moldable material 124 may include a mixture containing monomers as described in U.S. Patent No. 7,157,036 and U.S. Patent No. 8,076,386, both of which are incorporated herein by reference.

[0046] Different fluid dispensers 122 may use different techniques to dispense the moldable material 124. If the moldable material 124 is jettable, an inkjet-type dispenser may be used to eject the moldable material. For example, thermal inkjet, micro-electromechanical system (MEMS) based inkjet, valve jet, and piezoelectric inkjet are common techniques for dispensing jettable liquids.

[0047] The molding system 100 further comprises a curing system that phase-changes a liquid moldable material into a solid material, the surface of which may be determined by the shape of the molding surface 112. The curing system may include at least one radiation source 126 that directs chemical energy along an exposure path 128. The molding head and substrate positioning stage 106 may be configured to position the template 108 and substrate 102 in alignment with the exposure path 128. The radiation source 126 delivers chemical energy along the exposure path 128 after the template 108 has come into contact with the moldable material 124. Figure 1 shows the exposure path 128 when the template 108 is not in contact with the moldable material 124, but this is for illustrative purposes to allow for easy identification of the relative positions of the individual components. Those skilled in the art will understand that the exposure path 128 does not substantially change when the template 108 comes into contact with the moldable material 124. In one embodiment, chemical energy may be directed through both the template chuck 118 and the template 108 to the moldable material 124 beneath the template 108. In one embodiment, the chemical energy generated by the radiation source 126 is UV light that induces polymerization of monomers in the moldable material 124.

[0048] The molding system 100 may further include a field camera 136 positioned to observe the spread of the moldable material 124 after the template 108 has come into contact with the moldable material 124. In Figure 1, the optical axis of the imaging field of the field camera is shown by a dashed line. As shown in Figure 1, the molding system 100 may include one or more optical elements (such as a dichroic mirror, beam combiner, prism, lens, or mirror) that combine the chemical beam with the light detected by the field camera. The field camera 136 may be configured to detect the spread of the moldable material beneath the template 108. Thus, the field camera may also be called a spread camera. The optical axis of the field camera 136 shown in Figure 1 is straight, but may be bent by one or more optical components. The field camera 136 may include one or more of a CCD, a sensor array, a line camera, and a photodetector configured to collect light having wavelengths that show contrast between the area beneath the template 108 that is in contact with the moldable material and the area beneath the template 108 that is not in contact with the moldable material 124. The field camera 136 may be configured to collect monochromatic images in visible light. The field camera 136 may be configured to provide images of the spread of the moldable material 124 under the template 108, and separation of the template 108 from the cured moldable material, which can be used to track the imprint (molding) process. The field camera 136 may also be configured to measure interference fringes that change as the moldable material 124 spreads in the gap between the molding surface 112 and the substrate surface 130. The shape of the interference fringes may depend on the deformation of the molding surface 112 relative to the shape of the substrate surface 130.

[0049] The molding system 100 may further include a droplet inspection system 138 separate from the field camera 136. The droplet inspection system 138 may include one or more of a CCD, camera, line camera, and photodetector. The droplet inspection system 138 may include one or more optical elements such as a lens, mirror, optical diaphragm, aperture, filter, prism, polarizer, window, adaptive optical system, and / or light source. The droplet inspection system 138 may be positioned to inspect droplets before the molding surface 112 contacts the moldable material 124 on the substrate 102. In an alternative embodiment, the field camera 136 may be configured as the droplet inspection system 138 and used before the molding surface 112 contacts the moldable material 124.

[0050] The molding system 100 may further include a thermal radiation source 134 which can be configured to provide a spatial distribution of thermal radiation to one or both of the template 108 and the substrate 102. The thermal radiation source 134 may include one or more thermoelectromagnetic radiation sources which heat one or both of the substrate 102 and the template 108 without solidifying the moldable material 124. The thermal radiation source 134 may include SLMs such as digital micromirror devices (DMDs), liquid crystal silicon (LCoS), and liquid crystal devices (LCDs) to modulate the spatiotemporal distribution of thermal radiation. The molding system 100 may further include one or more optical elements used to combine chemical rays, thermal radiation, and radiation collected by a field camera 136 on a single optical path that intersects the imprint area when the template 108 comes into contact with the moldable material 124 on the substrate 102. The thermal radiation source 134 can deliver thermal radiation along the thermal radiation path (shown as two thick dark lines in Figure 1) after the template 108 has come into contact with the moldable material 124. Figure 1 shows the thermal radiation path when the template 108 is not in contact with the moldable material 124, which is done for illustrative purposes to facilitate identification of the relative positions of the individual components. Those skilled in the art will understand that the thermal radiation path does not substantially change even when the template 108 is in contact with the moldable material 124. In Figure 1, the thermal radiation path is shown to terminate at the template 108, but it may terminate at the substrate 102. In an alternative embodiment, the thermal radiation source 134 is located beneath the substrate 102, and the thermal radiation path is not combined with chemical rays and visible light.

[0051] The molding system 100 may further include a light source 135 capable of emitting measurement light 137. The light source 135 may be configured to emit visible light toward the substrate and template when the template and substrate are in close proximity to each other, as will be discussed in more detail below. The light 137 may be, for example, 470 nm light. The measurement light 137 may be monochromatic. The light source 135 may be an array of light-emitting diodes. The light source 135 may include one or more lasers. Although the light source 135 is shown as a separate element in Figure 1, in another exemplary embodiment, the light source 135 may be integrated with a thermal radiation source 134 or with a radiation source 126. A field camera / spread camera 136 may be configured to capture images of the template and substrate when the measurement light 137 is reflected by the template and substrate, as will be discussed later. The molding system 100 may include one or more optical elements that guide measurement light 137 through the molding surface 112, reflect back from the substrate surface 130 through the molding surface 112, and are received by the field camera 136. One or more optical elements can also guide the measurement light 137 reflected from the molding surface 112 to the field camera 136. Examples of one or more optical elements include, but are not limited to, lenses, mirrors, optical diaphragms, apertures, filters, optical combiners, optical splitters, prisms, polarizers, windows, and adaptive optical elements.

[0052] The substrate coating 132 may be applied to the substrate 102 before the moldable material 124 is dispensed onto the substrate. In one embodiment, the substrate coating 132 may be an adhesion layer. In one embodiment, the substrate coating 132 may be applied to the substrate 102 before the substrate is loaded onto the substrate chuck 104. In an alternative embodiment, the substrate coating 132 can be applied to the substrate 102 while the substrate 102 is on the substrate chuck 104. In one embodiment, the substrate coating 132 may be applied by spin coating, dip coating, drop dispensing, slot dispensing, etc. In one embodiment, the substrate 102 may be a semiconductor wafer, a glass wafer, a sapphire wafer, or some other material. In another embodiment, the substrate 102 may be a blank template (replica blank) that can be used to create a daughter template after imprinting.

[0053] The molding system 100 may include an imprint area atmosphere control system, such as a gas and / or vacuum system, examples of which are described in U.S. Patent Publication 2010 / 0096764 and U.S. Patent No. 10,895,806. These documents are incorporated herein by reference. The gas and / or vacuum system may include one or more of the following: pumps, valves, solenoids, gas sources, gas piping, etc., which are configured to flow one or more different gases at different times and in different areas. The gas and / or vacuum system may be connected to a first gas transport system that controls the imprint area atmosphere by transporting gas to and from the edges of the substrate 102 and controlling the flow of gas at the edges of the substrate 102. The gas and / or vacuum system may be connected to a second gas transport system that controls the imprint area atmosphere by transporting gas to and from the edges of the template 108 and controlling the flow of gas at the edges of the template 108. A gas and / or vacuum system may be connected to a third gas transport system that controls the atmosphere of the imprint area by transporting gas to and from the top of the template 108 and controlling the flow of gas through the template 108. One or more of the first, second, and third gas transport systems may be used in combination or separately to control the flow of gas in and around the imprint area.

[0054] The molding system 100 may be coordinated, controlled, and / or commanded by one or more processors 140 (controllers) that communicate with one or more components and / or subsystems, such as a substrate chuck 104, a substrate positioning stage 106, a template chuck 118, a molding head 120, a fluid dispenser 122, a radiation source 126, a heat radiation source 134, a light source 135, a field camera 136, an imprint area atmosphere control system, and / or a droplet inspection system 138. The processors 140 may operate based on instructions in a computer-readable program stored in non-temporary computer-readable memory 142. The processors 140 may be one or more of a CPU, MPU, GPU, ASIC, FPGA, DSP, and a general-purpose computer, or may include them. The processors 140 may be dedicated controllers or general-purpose computing devices adapted to be controllers. Examples of non-temporary computer-readable memory include, but are not limited to, RAM, ROM, CDs, DVDs, Blu-rays, hard drives, network-attached storage (NAS), intranet-attached non-temporary computer-readable storage devices, and internet-attached non-temporary computer-readable storage devices. The controller 140 is included in the molding system 100 and may include multiple processors that communicate with the molding system 100. The processors 140 can communicate with a network computer 140a where analysis is performed and control files, such as droplet patterns, are generated. In one embodiment, one or both of the displays communicating with the network computer 140a and the processors 140 have one or more graphical user interfaces (GUIs) 141 that are presented to the operator and / or user.

[0055] Either or both of the molding head 120 and the substrate positioning stage 106 vary the distance between the mold 110 and the substrate 102 to define a desired space (a defined physical area in three dimensions) to be filled with the moldable material 124. For example, the molding head 120 may apply force to the template 108 so that the mold 110 is in contact with the moldable material 124. After the desired volume is filled with the moldable material 124, the radiation source 126 generates chemical rays (e.g., UV, 248 nm, 280 nm, 350 nm, 365 nm, 395 nm, 400 nm, 405 nm, 435 nm, etc.) that cure, solidify, and / or crosslink the moldable material 124, conforming to the shape of the substrate surface 130 and the molding surface 112, and defining a pattern layer on the substrate 102. The moldable material 124 is cured while the template 108 is in contact with the moldable material 124, forming a pattern layer on the substrate 102. Therefore, the molding system 100 uses the molding process to form a patterned layer having recesses and protrusions, which are inversions of the pattern within the molded surface 112. In an alternative embodiment, the molding system 100 uses the molding process to form a flat layer having a featureless molded surface 112.

[0056] The molding process may be repeated over multiple imprint areas (which may simply be called fields or shots) spread across the substrate surface 130. Each full-field imprint area may be the same size as the mesa 110, or it may be a pattern area of ​​the mesa 110. The pattern area of ​​the mesa 110 is an area of ​​the molding surface 112, used to imprint (form) a pattern onto the substrate 102, which may be a feature of the device or used to form a feature of the device in subsequent processing. The pattern area of ​​the mesa 110 may or may not include mass velocity fluctuation features (fluid control features) used to prevent overflow from forming on the imprint area edges. In an alternative embodiment, the substrate 102 has only one imprint area (molding area) which is the same size as the area of ​​the substrate 102 that is patterned with the substrate 102 or the mesa 110. In the alternative embodiment, the imprint areas overlap. As described above, some of the imprinted areas may be partial fields or small partial fields that intersect with the boundary of the substrate 102.

[0057] The patterned layer may be formed to have a residual film having a residual thickness (RLT) which is the minimum thickness of the moldable material 124 between the substrate surface 130 and the molding surface 112 in each imprint region. The patterned layer may also include one or more features, such as protrusions, extending on the residual film having thickness. These protrusions coincide with the recesses 114 of the mesa 110. template

[0058] Figure 2A is a diagram (not to scale) of a template 108 that may be used in one embodiment. The molding surface 112 may be on a mesa 110 (identified by the dashed box in Figure 2A). The mesa 110 is surrounded by a concave surface 244 on the front side of the template. The mesa 110 has a mesa height h T It has a mesa height h. TThis can be between 1 and 200 μm. The mesa sidewall 246 connects the concave surface 244 to the forming surface 112 of the mesa 110. The mesa sidewall 246 surrounds the mesa 110. In embodiments where the mesa is rounded or has rounded corners, the mesa sidewall 246 refers to a single mesa sidewall that is a continuous wall without corners. In one embodiment, the mesa sidewall 246 may have one or more profiles, which are vertical profiles, inclined profiles, curved profiles, stepped profiles, S-shaped profiles, convex profiles, or combinations of these profiles. Figure 2B is a perspective view of the template 108 (not to scale) showing the mesa edge 210e. Figure 2B shows that the intersection of the mesa sidewall 246 and the concave surface 244 may have some curvature due to the process of etching away the material that forms the template precursor for forming the mesa 110 on the template 108. The template 108 has a template width w as shown in Figures 2A and 2B. T It may have a square plane having a template width w. In an alternative embodiment, the template width w T The width is a distinctive feature, and the planar shape of template 108 can be a rectangle, parallelogram, polygon, circle, or any other shape. T It can range from 10 to 450 millimeters. Molding process

[0059] Figure 3 is a flowchart of a method for manufacturing an article (device) that includes a molding process 300 performed by a molding system 100. The molding process 300 may be used to form a pattern of moldable material 124 on one or more imprint areas (also called pattern areas or shot areas). The molding process 300 may be repeatedly performed by the molding system 100 on multiple substrates 102. A processor 140 may be used to control the molding process 300.

[0060] In another embodiment, the substrate 102 is planarized using a molding process 300. In this case, the molded surface 112 is featureless and may be the same size as or larger than the substrate 102.

[0061] The start of the molding process 300 may include a template mounting step in which the template transport mechanism mounts the template 108 onto the template chuck 118. The molding process 300 may also include a substrate mounting step in which the processor 140 mounts the substrate 102 onto the substrate chuck 104 onto the substrate transport mechanism. The substrate may have one or more coatings and / or structures. The order in which the template 108 and the substrate 102 are mounted to the molding system 100 is not particularly limited, and the template 108 and the substrate 102 may be mounted sequentially or simultaneously.

[0062] In the positioning process, the processor 140 may move the imprint region i (index i may be initially set to 1) of the substrate 102 to the fluid dispensing position below the fluid dispenser 122, on either or both of the substrate positioning stage 106 and / or the dispenser positioning stage. The substrate 102 is divided into N imprint regions, each imprint region may be identified by a molding region index i, where N is the number of molding regions and is a real positive integer such as 1, 10, 62, 75, 84, 100 {N≧Z + In the dispensing step S302, the processor 140 causes the fluid dispenser 122 to dispense the moldable material based on the droplet pattern on the imprint area. In one embodiment, the fluid dispenser 122 dispenses the moldable material 124 as a plurality of droplets. The fluid dispenser 122 may include one or more nozzles. The fluid dispenser 122 may dispense the moldable material 124 simultaneously from one or more nozzles. The imprint area may move relative to the fluid dispenser 122 while the fluid dispenser is dispensing the moldable material 124. Therefore, the imprint area i may change when some of the plurality of droplets land on the substrate. The dispensing step S302 may be performed for each imprint area i during the dispensing period Td.

[0063] In one embodiment, during the dispensing process S302, the moldable material 124 is dispensed onto the substrate 102 according to a droplet pattern. The droplet pattern may include one or more pieces of information, such as the location for depositing droplets of the moldable material, the volume of the droplets, the type of moldable material, and the shape parameters of the droplets of the moldable material. In one embodiment, the droplet pattern may include only the volume of the droplets to be dispensed and the location for depositing the droplets.

[0064] After the droplet is dispensed, a contact process S304 is initiated, in which the processor 140 may bring the molding surface 112 of the template 108 into contact with the moldable material 124 in a specific imprint area with one or both of the substrate positioning stage 106 and the template positioning stage. The contact process S304 may be initiated after the dispensing period Td and performed during a contact period Tcontact, which begins with the first contact of the molding surface 112 with the moldable material 124. In one embodiment, by the start of the contact period Tcontact, the template chuck 118 is configured to bend the template 108 so that only a portion of the molding surface 112 is in contact with a portion of the moldable material. In one embodiment, the contact period Tcontact ends when the template 108 is no longer bent by the template chuck 118. The degree to which the molding surface 112 is bent relative to the substrate surface 130 can be estimated using a spread camera 136.

[0065] During the filling process S306, the moldable material 124 spreads toward the edges of the imprint area and the mesa sidewalls 246. The edges of the imprint area may be defined by the mesa sidewalls 246. How the moldable material 124 spreads and fills the mesa can be observed via a field camera 136 and used to track the progress of the fluid front of the moldable material. In one embodiment, the filling process S306 takes place during a filling period Tf. The filling period Tf begins when the contact process S304 is completed. The filling period Tf ends with the start of the curing period Tc. In one embodiment, the back pressure and the force applied to the template are kept substantially constant during the filling period Tf. In this context, substantially constant means that the back pressure fluctuations and force fluctuations are within the controllable tolerance of the molding system 100, which may be less than 0.1% of the setpoint.

[0066] In curing step S308, the processor 140 can instruct the radiation source 126 to transmit a chemical beam curing illumination pattern through the template 108, mesa 110, and molding surface 112 during the curing period Tc. The curing illumination pattern provides sufficient energy to cure (polymerize) the moldable material 124 under the molding surface 112. The curing period Tc is the period during which the moldable material under the template receives a chemical beam with sufficient intensity to solidify (cure) the moldable material. In an alternative embodiment, the moldable material 124 is exposed to a chemical beam gelling illumination pattern before the curing period Tc. The curing period Tc does not cure the moldable material but increases its viscosity.

[0067] In separation step S310, the processor 140 uses one or more of the substrate chuck 104, substrate positioning stage 106, template chuck 118, and molding head 120 to separate the molding surface 112 of the template 108 from the cured moldable material on the substrate 102 during the separation period Ts. If there are additional imprint areas to be imprinted, the process returns to step S302. In an alternative embodiment, during step S302, the moldable material 124 is received in two or more imprint areas, and the process returns to step S302 or S304.

[0068] In one embodiment, after the molding process 300 is completed, an additional semiconductor manufacturing process is performed on the substrate 102 in the processing step S312 to produce a manufactured product (e.g., a semiconductor device). In one embodiment, each imprint area includes multiple devices.

[0069] Further semiconductor manufacturing processes in processing step S312 may include etching to transfer a relief image corresponding to the pattern in the patterned layer or its inverted pattern onto the substrate. Further processes in processing step S312 may also include known steps and processes for manufacturing articles, such as inspection, curing, oxidation, layer formation, deposition, doping, planarization, etching, moldable material removal, dicing, bonding, packaging, mounting, and circuit board assembly. The substrate 102 may be processed to manufacture multiple articles (devices). Layout of fields on the circuit board

[0070] The molding process 300 can be used in a step-and-repeat manner to form a film using a template 108 across multiple fields on the substrate 102. The patterning areas (mesas 110) of the substrate 102 and template 108 may have different shapes and sizes. For example, the substrate 102 may have areas to be patterned in a circular, elliptical, polygonal, or some other shape. The mesa 110 is typically smaller than the substrate 102 and has a different shape from the substrate 102. The substrate 102 is divided into multiple full fields and multiple partial fields / small partial fields, as shown in Figures 4A to 4B. As described above, a full field is the same size as a mesa 110 or the patterning area (molding surface) of a mesa. That is, the total surface area of ​​a mesa 110 is equal to the area of ​​one full field, such that the total surface area of ​​the molding surface overlaps with the substrate. Partial fields and small partial fields are regions on the edge of the substrate where the edge of the patterned area on the substrate intersects with the patterned area of ​​the mesa (molding surface), and the molding surface overlaps with the edge of the substrate. As described above, a partial field is a region whose area is smaller than the area of ​​the full field, and this is also smaller than the total surface area (molding surface) of the mesa 110. These regions can be divided into several categories based on their shape and / or area relative to the full field. A subset of these partial fields can be classified as small partial fields. A partial field may be defined as having a surface area less than the total surface area of ​​the mesa 110, or as having a surface area of ​​5% to 99% of the total surface area of ​​the mesa, or as having a surface area of ​​10% to 95% of the total surface area of ​​the mesa. A small partial field may be defined as having a surface area equal to 50% or less (or 35% or less) of the area of ​​a full field, which is 50% or less (or 35% or less) of the total surface area of ​​Mesa 110. Small Partial Field

[0071] FIG. 4C is a diagram of a particular small partial field 448 on the substrate 102 in the coordinate system of the mesa 110. In FIG. 4C, the mesa edge 210e is shown as a dotted line. Also shown in FIG. 4C is the mesa origin O of the coordinate system of the mesa at the center of the mesa 110. i, m The patterning possible region edge 450 is shown inside the substrate edge. In one embodiment, the patterning possible region edge 450 can be within 0 to 3 mm inside the substrate edge. The unpatterned region is shown in FIG. 4C as a diamond grid pattern. The width of the unpatterned region can be determined by the edge treatment of the substrate 102 processed to have a rounded edge, a bevelled edge, or a chamfered edge. The substrate 102 may also have undergone a number of previous processes to make the edge have a random, unpredictable pattern. The substrate 102 may also have directional features such as a notch or a flat edge.

[0072] As shown in FIG. 4C, the range of the particular small partial field 448 is defined by two sides by the mesa edge 210e that intersects at vertex B. The range of the small partial field 448 is also defined by the arc of the patterning possible region edge 450. The arc of the patterning possible region edge 450 can be defined as part of a circle, an ellipse, a spline, a polygon, or other geometric quantity that can be used to define the shape of the patterning possible region edge 450. The arc of the patterning possible region edge 450 intersects the mesa edge 210e at vertices A and C. This is an exemplary small partial field. The small partial field can have other shapes having at least a curved edge and one or more straight edges. Target initial contact point

[0073] The shaping process 300 is controlled using a number of parameters. In one embodiment, one of the process parameters used during the contact step S302 is the target initial contact point (ICP) for each field i (ICP i ={ICP i,θ 、ICPi,r}). In one embodiment, the substrate center (O s The target ICP can be described using polar coordinates relative to ). Target ICP i The location is also Mesa O i,m The angle θ with respect to the center i,m It may be described as follows. In alternative embodiments, a different coordinate system may be used. The target ICP is a point in the field where the template 108 should first make contact with the moldable material 124 on the substrate 102. The template 108 is curved by the template chuck 118 so that only a small portion of the template 108 makes contact with the moldable material 124 at the target ICP. The curvature of the template is reduced as the template approaches the substrate until the template becomes flat. This is done to allow gases to escape during the contact process S304 and to ensure that the moldable material spreads in a controlled manner.

[0074] In the case of a full field, the target ICP is located in the center of the full field, near Mesa O i,m There is. In a partial field, the shape and area of ​​the partial field, and the center of the substrate (O sDetermining the target ICP is more complex depending on the location of the partial field relative to the full field. For a particular partial field (e.g., one with an area between 50% and less than 100% of the full field's area), the target ICP may be at the same point as the full field or somewhere within the initial contact area. For other partial fields (e.g., one with an area between 25% and 50% of the full field's area), the target ICP can be determined by calculating the geometric center (GC) or centroid of the partial field. There are several methods that can be used to determine the GC. One method for estimating the GC is to use a method of intersecting meridians. Another method is to approximate the edges of the partial field using a function. The function may be piecewise defined and continuous across the partial field. The geometric center of the partial field can then be estimated using integration. A third method for identifying the GC is to minimize the distance from the GC to the furthest corner of the partial field.

[0075] GC does not work well for small partial fields. One method for determining the target ICP for a small partial field is described in U.S. Patent Application Publication 2023-0014261, which is incorporated herein by reference. As described above, in one embodiment, a partial field may be classified as a small partial field if it has an area less than the small area threshold, such as 50% or 35% of the area of ​​the full field. In an alternative embodiment, the small area threshold may have different values, such as 1%, 5%, 10%, 15%, 20%, 25%, 30%, 45%, or 50%. In one embodiment, the target ICP may not be a GC for a small partial field, but rather a GC for a partial field that coincides with the center of a mesa or, alternatively, is not classified as a small partial field.

[0076] As shown in Figures 4A-B, different layouts of the imprint area result in different sizes and shapes of the partial field. In the example where the mesa is quadrilateral and the substrate is circular, the partial field can have a complex shape with 1-4 straight edges and 2-5 curved edges intersecting at vertices. Knowing the shape of the partial field is necessary when determining the ICP control value for the partial field. A conventional method for describing the shape of a partial field is to identify the positions of all vertices of the shape and the shape of the lines connecting all these vertices. Another method for describing a partial field is to describe it as the intersection of two figures and list the size, shape, and relative position of those figures. This provides a complete description of the partial field, but is not necessary for the purpose of determining the ICP control value. Partial field shape description F of partial field i i This can be simplified to two or three parts. For example, the partial field shape description set F i is full field (F i, A The area of ​​the partial field shape relative to the area of ​​the substrate, and the azimuth angle (F) representing the in-plane angle of the mesa center relative to the center of the substrate, as shown in Figure 4D. i,θ )(F i ={F i,A F i,θ}) may include. Also, Figure 4D shows the target ICP of imprint region i (ICP i = {ICP i, r ICP i,θ}) is shown. As shown in Figure 4D, the azimuthal coordinates (ICP) of the imprint region i are shown. i, θ ) is a partial field shape description (F i,θ Although it differs from the azimuth coordinates of (), it may be the same depending on the situation. Method for determining the ICP control code

[0077] A method for determining ICP control values / parameters is disclosed in U.S. Patent Application Publication No. 2024 / 0329542 (hereinafter referred to as "Publication 542"), filed on 28 March 2023. By this reference, the entirety of that document is incorporated herein by reference. In particular, the section entitled "Method for Determining ICP Control Values" in Publication 542 is the most relevant part. The molding process 300 includes a contact step S304. As described in Publication 542, the contact step S304 sets the contact control values ​​V of the partial field i from the processor 140. i This includes receiving the contact control value set V. i This may include: being applied to a portion of the template during initial contact of the template 108 to the moldable material 124 on the substrate 102, with a radius of curvature R T Curving template 108 with template cavity pressure P T ; Applied to a portion of the substrate during the initial contact of the template with the moldable material on the substrate, with a radius of curvature R S Set the substrate pressure (P) to bend the substrate 102 in the partial field. Sa , P Sb , P Sc ); the inclination of the template relative to the substrate during the initial contact of the template with the moldable material on the substrate (θ T ). Publication No. 542 provides a flowchart for the ICP control value determination process for a small partial field 448. By implementing the method described in Publication No. 542, a set of calibration data C related to a specific imprint process j, including the following data, is obtained. j It is possible to establish: the slope of the template (θ) j, T ); One or more substrate pressure control values ​​(P j,Sa , P j,Sb , P j,Sc ); template cavity pressure (P j,T ); Area of ​​the partial field (F j,A ); and the azimuth angle of the partial field (F j,θAs described in Publication No. 542, the superset C of calibration data is a set of calibration data C of 10s, 100s or 1000s. j It may include.

[0078] As described in Publication No. 542, the ICP control value determination process is performed when template 108 is ICP i, D A set of contact control values ​​V that allows initial contact with the moldable material 124. i Partial field description F i and may include a control condition determination step determined based on a superset C of calibration data. The control condition determination step may include a set of contact point control values ​​V that can be used to imprint the partial field i in step S304. i It can output the following: Set contact point control value V i The template cavity pressure P i, T , substrate pressure (P i,Sa , P i,Sb , P i,Sc ) set, and template tilt (θ i,T ) may include. Initial contact control value (control parameter)

[0079] As discussed in Publication 542, set of contact control values ​​V for imprint region i. i This is the template back pressure (P) applied to the back surface of the template by the template chuck 118. i, T) may include. This pushes the template 108 outward when imprinting the partial field i. Figure 5A shows a pump connected to an exemplary template chuck 108 for holding the template 108. Its details are described in U.S. Patent Publication 2017 / 0165898. This reference incorporates the entirety of that document herein. The template chuck 118 may include one or more vacuum portions for holding the template 108 and a chamber portion that can be used to curve the template 108 when the template is in contact with the full field i, as shown in Figure 5B. By making the pressure in the chamber higher than the ambient pressure on the molding surface 112, the template 108 is curved and the molding surface 112 has a radius of curvature (R) of the template in ICP. T The curvature is made to be approximated by ). Template R T The radius of curvature is an approximation of the shape of the molded surface 112 in the ICP. A polynomial (e.g., a quartic polynomial) can also be used to approximate the shape of the molded surface 112 in the ICP region at initial contact. Finite element models or other simulation models can be used to determine the shape of the molded surface under different control conditions.

[0080] The control state is the template's tilt angle (θ of the template centered on the x-axis). Tx Rotation) and the template's tilt angle (θ of the template centered on the y-axis). Ty This may include rotation. These together include the template control angle (θ) relative to the substrate as shown in Figure 5C when imprinting the full field i. i, T ={θ i,Tx θ i,Ty}) In one embodiment, θ Tx In the imprint region i, θ Ty G can be a function of one or both components of the partial field description F (θ i, Tx =G(θ i, Ty ,F i))). In this case, only one component of the template control angle needs to be known. The function G may be determined experimentally or by simulation so that constant conditions are maintained. The imprint head 120 may include a plurality of actuators used to position the template 108 relative to the substrate 102, and these actuators can also be used to tilt the molding surface 112 relative to the substrate 102. Figure 5C shows the tilt of the reference surface (surface of the template chuck) relative to the substrate 102 at the same angle as the molding surface 112 when not curved.

[0081] The control conditions may include a set of substrate chuck control values ​​supplied to the substrate chuck 104. The substrate chuck 104 can deform the substrate 102. As shown in Figure 5D, the substrate chuck 104 may be a zone chuck that can supply different amounts of positive or negative pressure to different zones (e.g., outer zone 504a, first inner zone 504b, second inner zone 504c, etc.) to deform the substrate between 1 and 10 μm. The substrate chuck 104 has at least two zones, but may have three, four, five, six, seven, eight, nine, ten, or more zones. For example, positive pressure may be supplied to the first inner zone 504b, and negative pressure to the outer zone 504a and the second inner zone 504c. Similar to the template, the shape of the substrate surface 130 is determined by the radius of curvature (R) of the substrate in ICP. S It can be approximately represented by ). A polynomial (e.g., a fourth-degree polynomial) can also be used to approximate the shape of the molded surface 112 in the ICP region at initial contact. A finite element model or other simulation model can be used to determine the shape of the molded surface under different control conditions.

[0082] Control conditions (Template radius of curvature R) T Template cavity pressure P for controlling T Radius of curvature R of the substrate S Substrate pressure P for controlling Sa , P Sb , P Sc; template slope θ Tx and θ Ty These parameters (etc.) can be adjusted in combination or independently to control where the ICP is located on the small partial field 448, as shown in Figure 5E. The control parameters may include additional parameters describing the shape and orientation of the molded surface 112 in the ICP, as well as the substrate surface 130 in the ICP. The control parameters may include multiple control values ​​and / or trajectories (pressure, current, voltage, binary control signals, etc.) used to determine the shape and orientation of the molded surface 112 and the substrate surface 130 in the ICP. The applicant has found that there are typically several different solutions for selecting control parameters to achieve a particular ICP. The choice of which of these solutions is appropriate may depend on the small partial field size, overlay constraints, alignment constraints, defect rate, process time, etc. This also affects which control parameters are adjusted, as described in Publication No. 542. As described in Publication No. 542, the adjusted control parameters are the partial field area F i, A and / or partial field azimuth (F i,θ Depending on the other control conditions, the template cavity pressure P T This may be done by adjusting the settings.

[0083] The pressure supplied to the chamber is the desired radius of curvature (R) during the filling process S306 in ICP. T , R Sdepends on ), which can be determined based on reducing unfilled defects caused by the gas not escaping during a given filling time during the filling process S306. There are control constraints on the control parameters based on the mechanical characteristics of the template 108, the substrate 102, and the molding system 100. These constraints prevent the concave surface 244 of the template from contacting the substrate surface 130 or the up-ricer surrounding the substrate, and / or prevent the molding surface 112 from contacting the up-ricer surrounding the substrate. In an alternative embodiment, the ICP is selected within the ICP range based on the constraints of the control parameters. These constraints can be determined experimentally and / or using a finite element model or other simulation methods. For example, when both the template and the substrate are flat, the template angle can be calculated using trigonometry as described in the following equation (1). Once the shape of the curved molding surface 112 and / or the shape of the curved substrate surface 130 are determined, the constraints can be determined using a coordinate transformation. θ i, Tx and θ i,Ty The relationship of is θ i,Tx and θ i,Ty For the ideal values of, it is also represented by the following equation (1). The applicant has found that the ideal solution is not necessarily effective, and other values of θ i, Tx and θ i,Ty need to be determined through simulation and experimentation.

Equation

[0084] As discussed in the ’542 publication, each element of the superset C of calibration data j should include a control value V j , a partial field description F j , and an initial contact point ICP j . Each set C of calibration data jcan be determined experimentally. As shown in FIG. 5F, a series of experiments are performed in a series of different partial fields. For each partial field j having a specific partial field description (F j ), a number of experiments are performed using different sets V j of control values that each generate a different ICP j . An example of such an experiment is described in the '542 publication. Forming method

[0085] FIG. 6 is a flowchart of a forming method 600 according to an exemplary embodiment. FIG. 7 is a flowchart of a forming method 700, showing a detailed example of the forming method 600.

[0086] The forming method 600 starts from step S602 where the distance d1 between the template 108 and the substrate 104 is reduced. The distance d1 can be the distance between the forming surface 112 and the substrate surface 130 in the ICP, as shown in FIGS. 8A to 12A in the imaging direction of the field / spread camera. The distance d1 can be the distance between the template reference plane and the substrate reference plane. The template reference plane can be, for example, the template chuck surface or a plane parallel to the template chuck surface. The substrate reference plane can be, for example, the substrate chuck surface or a plane parallel to the substrate chuck surface. The distance d1 can be reduced by moving the template 102 towards the substrate 104 with the substrate 104 stationary, by moving the substrate 104 towards the template 102 with the template 102 stationary, or by moving them towards each other with neither the template 102 nor the substrate 104 stationary. The methods by which the template and / or the substrate can be moved have been described above. While the distance d1 is being reduced, the method can perform steps S604 and step S606.

[0087] In step S604, while the distance d1 is being reduced, one or more states of the template 102 and the substrate 104 are controlled. That is, in step S604, while the distance d1 is being reduced, in one embodiment only the state of the template 102 can be controlled, and in another embodiment only the state of the substrate 104 can be controlled. In yet another exemplary embodiment, both the states of the template 102 and the substrate 104 can be controlled. State control is performed by implementing one or more of the control parameters described above. That is, the control parameter is the radius of curvature R of the template. T The above template cavity pressure P for controlling the pressure T , the radius of curvature R of the substrate S Substrate pressure P for controlling Sa , P Sb , P Sc , template slope θ Tx and θ Ty These are some examples. As will be discussed below with respect to Figure 7, there may be two or more examples of performing a step to reduce the distance while controlling the state of the template and / or substrate. In the first example where the distance d1 is reduced first, the initial control parameters are determined by the method described above in an attempt to achieve the target ICP described above. In other words, the initial control parameters are predetermined in an attempt to achieve a given target ICP. The method described herein can be applied to adjust one or more of the control parameters to achieve an actual ICP that is closer to the target ICP.

[0088] Referring to Figure 7, steps S702 to S706 correspond to steps S602 and S604 in Figure 6. As shown in Figure 7, method 700 can begin with step S702, where the target ICP and the initial control parameters corresponding to the target ICP (e.g., one or more of the template cavity pressure, substrate pressure, and template inclination) are received or determined. The target ICP and the corresponding initial control parameters are determined as described above. Importantly, as described above, for partial fields / small partial fields, the control parameters and target ICP are unique to each partial field / small partial field. Next, method 700 can proceed to step S704, where the initial control parameters can be applied to the template and / or substrate to control the template and / or substrate. That is, as described above, the state of the template, the state of the substrate, or both are controlled depending on which initial control parameters are used for the target ICP. Then, method 700 can proceed to step S706, where the distance d1 between the template and the substrate is reduced. The initial control parameters are used to control the state of the template and / or substrate while the distance d1 is reduced.

[0089] Figure 8A is an explanatory diagram of the template and substrate at the moment corresponding to step S604 in Figure 6 and step S706 in Figure 7. As shown in Figure 8A, the template is positioned to imprint a partial field. Thus, the molding surface of the template overlaps with the edge of the substrate in Figure 8A. In the exemplary embodiment of Figure 8A, the template 108 is in the process of moving downward toward the substrate 104 (thereby reducing the distance d1), but the template cavity pressure (P T Control parameters for the template are applied to control the state of the template. In this example, for simplicity of explanation, only control of template cavity pressure and template tilt is applied, but as mentioned above, any combination of control parameters can be applied to control the state of the template and / or substrate.

[0090] As the distance d1 is reduced, method 600 can proceed to step S606 in which the light intensity of the light reflected from both the template and the substrate is detected. While the distance d1 is being reduced, visible measurement light 137 is emitted from the light source 135. The measurement light 137 may have a measurement wavelength λ, such as the peak wavelength of the light received by the field camera 136, which is 470 nm. As shown in Figure 8A, the measurement light 137 passes through the transparent template 108 and reaches the substrate 102. When the measurement light 137 passes through the template 108 and reaches the substrate 102, some of the light is reflected by the template 108 (the reflectivity of the template may be, for example, 2-5%), and some of the measurement light is reflected by the substrate 102 (the reflectivity of the substrate may be, for example, 20-40%). These reflections produce interference patterns known in the art as interference fringes or Newton's rings, which can be measured by the field camera 136. That is, the interference patterns resulting from the reflected light appear as multiple concentric rings, i.e., multiple extended rings having the same center point. The appearance and intensity of interference fringes vary based on the distance d1 between the molded surface 112 and the substrate surface 130. The substrate 102 may have multiple coatings that generate multiple reflections, which can affect the ability to predictably estimate d1 in all situations based solely on interference fringes. Despite this limitation, the applicant has found that a reliable relative estimate of the distance d1 can be obtained with the field camera 136. When the distance d1 is relatively large (e.g., on a scale of 20λ to 30λ or larger), no perceptible interference fringes are present. This depends on the reflectivity of the substrate, the reflectivity of the template, the curvature of the template, the curvature of the substrate, and the sensitivity of the field camera 136. When the distance d1 is relatively small (e.g., on a scale of 20λ to 30λ), the interference fringes are perceptible and become clearer as d1 decreases.

[0091] As described above, the field camera / spread camera 136 may be configured to collect images of the template and substrate as measurement light 137 is radiated onto it by the light source 135. The field camera 136 may be configured to acquire video at a specified frame rate. Non-limiting examples of specified frame rates are 15Hz, 30Hz, 60Hz, 120Hz, 164Hz, 240Hz, and 1000Hz. Each frame of the video may be considered an image. Each image can be analyzed by the processor 140. As d1 decreases, the field camera / spread camera 136 calculates K as a function of time of the template and substrate when the measurement light 137 is reflected by both the template and the substrate. a (d1(t)) is repeatedly imaged. Figure 8B is an exemplary image K taken when template 108 is in the position shown in Figure 8A. a (d1(t0)) is shown. As seen in Figure 8B, there are no recognizable interference fringes yet; that is, no concentric rings appear in the image of Figure 8B. Exemplary image K a (d1(t0)) can be used as a reference image for the background only.

[0092] Figure 9A shows the moment after Figure 8A where the distance d1 is reduced and the template 108 is closer to the substrate 102 than in Figure 8A. Figure 9B is an exemplary image K when the template 108 is at position d1 at time t2 shown in Figure 9A. a (d1(t2)) is shown. As can be seen in Figure 9B, there is a slight appearance of interference fringes 902, that is, interference fringes 902 are beginning to become perceptible within box 904.

[0093] Figure 10A shows the moment when d1 is smaller at time t4 and the template 108 is closer to the substrate 102 than in Figure 9A. Figure 10B is an exemplary image K taken when the template 108 is in the position shown in Figure 10A. aThis shows (d1(t4)). As seen in Figure 10B, there is a clearer appearance of interference fringes 1002, i.e., interference fringes 1002 within box 1004 are more perceptible compared to Figure 9B.

[0094] Figure 11A shows the moment when the distance d1 is smaller at time t5 and the template 108 is closer to the substrate 102 than in Figure 10A. Figure 11B is an exemplary image K taken when the template 108 is in the position shown in Figure 11A. a This shows (d1(t5)). As can be seen in Figure 11B, the appearance of the interference fringe 1102 is clearer, that is, the interference fringe 1102 in box 1104 is clearer compared to Figure 10B.

[0095] Step S606 of Method 600 includes measuring the light intensity of reflected light (light intensity information) over a period of time during which the distance d1 is reduced. That is, the camera 136 takes images (detects light intensity) multiple times, for example, 2, 5, 10 to 300 times, as the distance d1 decreases. This step also corresponds to step S706 of Method 700, in which an image is recorded using the camera 136.

[0096] For each captured image, the method proceeds to step S608, where it is determined whether predetermined light conditions are met based on the detected light intensity. The predetermined light condition is whether interference fringes have reached a sufficient presence to indicate that the template is very close to the substrate but has not yet made contact. In other words, by analyzing and processing the light intensity information recorded by the camera and using predetermined threshold information, it is possible to determine whether sufficient interference fringes are present for each image.

[0097] The process of analyzing each individual image as the distance d1 is reduced is shown in steps S708-S710 in Figure 7. In step S708, the first image is processed / analyzed. In step S710, it is determined whether there are sufficient interference fringes. If the answer to step S710 is "No", the method proceeds to S712, and the distance d1 continues to be reduced. Next, the method returns to step S708, the next image is analyzed, and the determination of whether there are sufficient interference fringes is made for that image. This process of steps S708-S712 is repeated until the answer to step S710 is "Yes".

[0098] The process for analyzing the image and determining whether sufficient interference fringes are present is as follows. Figures 13A-B show images of interference fringes obtained after contact (1317 K). a Figure 12B shows a series of images representing the process of processing (d1(t7)) (part of the process of determining whether predetermined light conditions are met (process S608) and whether interference fringes exist (process S710)). The processing for analyzing the images is an image 1310 K containing only the background of the partial field imprinted by the template. a This may include capturing (d1(t0)). This background-only image is 1310 K. a (d1(t0)) should be obtained while the template is sufficiently far away so that no visible streaks appear in the background-only image 1310. This can be captured before the template approaches the substrate. First image 1302 K in Figure 13A a (d1(t7)) is the original image of Figure 12B, taken by camera 136 when template 108 is separated from substrate 102 shown in Figure 9A. The second image 1304 in Figure 13A is the first image 1302 to image K a This is the image after the processing step of subtracting the background (d1(t0)) (K b (d1(t7))=K a (d1(t7))-K a(d1(t0))). The background is subtracted by using a background-only image taken by the camera before processing, before the distance d1 is reduced to a point where interference fringes are known to be undetectable. That is, the background-only image is a reference image that contains all the existing light information, even before the distance d1 begins to be reduced, or even if it has only been slightly reduced. The distance d1 when the reference image is obtained should be, for example, at least 10 μm, but may be larger. Background-only reference image K a By subtracting (d1(t0)) from the first image 1302, only the light intensity information regarding interference fringes (if any) remains in the second image 1304, along with some background noise. Subtraction can be performed by subtracting the light intensity of a background-only reference image from the first image 1302 pixel by pixel. The example in Figure 13A shows a case where the distance d1 is relatively small (i.e., the template is relatively close to the substrate at this point), and the interference fringes are very visible, but this information is still useful and can be obtained later in the imprint process.

[0099] Next, image processing may include denoising and filtering the second image 1304 to obtain a third image 1306. This involves setting the luminosity information of individual pixels as the average value of the surrounding pixels (K b (d1(t7)→K c This is achieved using standard denoising / filtering techniques such as (d1(t7))). Examples of denoising / filtering techniques include, but are not limited to, convolutional space filtering, convolutional neural networks, and mathematical forms. Convolutional space filtering techniques can use any one of various kernels. Examples of kernels include, but are not limited to, box filters, Gaussian filters, sharp, ridge, and adaptive filters. For example, denoising / filtering can involve two steps: non-local means denoising and a two-pole low-pass Butterworth filter. The filtered image is then rescaled (K c (d1(t7)→K d(d1(t7))). Image K with stripes c (d1(t7)) has an effective DC component. This image K c (d1(t7)) is rescaled so that the DC component is removed. For example, image K c The median (d1(t7)) is calculated and set to the integer value 0, generating the AC component image 1307 shown in Figure 13B. K d (d1(t7))=K c (d1(t7))-median(K c (d1(t7))) (1) Then, the AC component image 1307 is normalized to obtain the fourth image 1308 shown in Figure 13B (K d (d1(t7)→K e (d1(t7))). The AC component image 1307 can be normalized by rescaling over a fixed range (e.g., the natural range of an unsigned 8-bit integer image, 0 to 255), as shown in the normalized image 1308 in Figure 13B. Normalization is achieved using standard techniques, such as averaging the light intensity across all pixels in the image and then subtracting the average from each pixel. Figure 13C shows the results of performing this image analysis process for 6 frames as the template approaches the substrate. For example, the image 1312 obtained at time t2 (frame number 2) is analyzed using the method described above, and the normalized image 1322(K d (d1(t2)→K e (d1(t2))) can be obtained. For example, the image 1313 obtained at time t3 (frame number 3) can be analyzed using the method described above to obtain the normalized image 1323(K d (d1(t3)→K e (d1(t3))) can be obtained. For example, the image 1314 obtained at time t4 (frame number 4) can be analyzed using the method described above to obtain the normalized image 1324(K d (d1(t4)→K e (d1(t4))) can be obtained. For example, the image 1315 obtained at time t5 (frame number 5) can be analyzed using the method described above to obtain the normalized image 1325(K d(d1(t5)→K e (d1(t5))) can be obtained. For example, the image 1316 obtained at time t6 (frame number 6) can be analyzed using the method described above to obtain the normalized image 1326(K d (d1(t6)→K e (d1(t6))) can be obtained. For example, the image 1317 obtained at time t7 (frame number 7) can be analyzed using the method described above to obtain the normalized image 1327(K d (d1(t7)→K e (d1(t7))) can be obtained. As can be seen in Figure 13A, the distance d1 is relatively large (i.e., the template is relatively far from the substrate at this point), and there are almost no interference fringes, so the fourth image 1304 does not show much that interference fringes are present.

[0100] After generating the fourth image 1304, frame statistics are obtained from the fourth image 1304. Frame statistics can represent, for example, the signal-to-noise ratio (SNR). There are various methods for calculating frame statistics. One method of calculating frame statistics is to normalize the image and calculate the median intensity of the normalized image. Another method of calculating frame statistics is to take the difference between the median intensity and the minimum intensity. Another method of calculating frame statistics is to divide the mean intensity of the fourth image by the standard deviation of the intensity of the fourth image. Another method of calculating frame statistics is to find the value obtained by dividing the median by the range. Another way to represent frame statistics is to find the value obtained by dividing the maximum intensity by the minimum intensity. Another method involves creating a histogram and identifying the statistical characteristics of one or more peaks in the histogram. Another way to represent the statistics is to find the value obtained by subtracting the minimum intensity from the maximum intensity. There may be limited time and computational resources to make meaningful decisions about frame statistics so that decisions can be made to determine whether a low computational representation of frame statistics that is sufficiently accurate is useful. Figure 14 shows how frame statistics change with frame number.

[0101] While interference fringes are sufficiently present, frame statistics that adequately represent when interference fringes are present before contact between the template and the substrate occurs can be experimentally predetermined. For example, a representative partial field can be imprinted, images can be taken, and the same process as above can be performed to calculate frame statistics. Images of the representative partial field can be taken over a period in which d1, which includes all contact with the substrate, is reduced. Images corresponding to the moment immediately before contact and images corresponding to contact or after are identified. Then, frame statistics are obtained for the images where interference fringes are sufficiently present but before contact occurs. Thus, a range of frame statistics that correlates with the moment when interference fringes are sufficiently present is known. In an exemplary embodiment, the target frame statistics range could be, for example, 20 to 35 when the images are normalized to a range of 0 to 255. If the frame statistics are much higher, this indicates that the template is too close to the substrate or has already made contact with the substrate. For example, using a frame statistics range of approximately 140 or higher can be used to conclude that the template is too close to the substrate or that contact has already occurred. The applicant found that when the frame statistics fall below a lower threshold (e.g., 80 or 127 when normalized to a range of 0-255), the interference fringes provide misleading information about the location of the initial contact point. When the frame statistics exceed an upper threshold (e.g., 150 when normalized to a range of 0-255), the template is either too close to the substrate or in contact with the substrate, thus requiring a set of contact control values ​​V. i It's too late to change it.

[0102] In the examples of Figures 9B, 10B, 11B, and 12B, the frame statistics are determined to be 18, 77, 141, and 157 according to the above process. Since the frame statistics are lower than, for example, 80 or 127 (when the image is normalized to 0-255), it is determined that there are not yet enough interference fringes. The threshold is determined based on the range to which the frame is normalized, which is typically around the middle of the range, but can be higher or lower depending on the system. That is, at the moment shown in Figure 9A, when the template 108 is relatively far from the substrate 102, it is determined that there are not yet enough interference fringes. Therefore, at the moment shown in Figures 9A and 9B, the conclusion of step S608 of method 600 is that the given optical conditions are not met. Similarly, for the moment shown in Figures 9A and 9B, the conclusion of step S710 of method 700 is "NO". In the above explanation, the positions in Figures 9A and 9B are used as examples, but the same process is repeated many times (i.e., tens, hundreds, or thousands of times), including the moment shown in Figures 8A / 8B. The analysis of Figure 8B yields the same results as the analysis of Figure 9B. This is because the distance d1 at moment t0 in Figures 8A and 8B is greater than the distance d1 at moment t2 in Figures 9A and 9B.

[0103] Since the end of step S710 is "NO", method 700 proceeds to step S712, where the distance d1 is further reduced. Subsequently, the analysis of steps S708 and S710 is repeated. These steps are repeated until the answer to the presence of interference fringes is determined to be YES. Figures 10A and 10B show exemplary moments in which the distance d1 is further reduced compared to the moments in Figures 9A and 9B. The same analysis described above is performed at this point and at other points in between. Figure 10B shows an example in which the interference fringes have become more visible, but the frame statistics are still below the target frame statistics range, although they are quite close to it. Thus, image K in Figure 10B a For (d1(t4)), S710 remains "NO". Similarly, in process S608, the predetermined light conditions are met.

[0104] For the image in Figure 10B, the answer to step S710 is "NO", so the method can proceed to continue reducing the distance d1. Eventually, this process reaches the moment t5 shown in Figures 11A and 11B. At this moment, the distance d1 has decreased further compared to the moment t4 in Figures 10A and 10B. As shown in Figure 11B, the interference fringes are more visible. Figure 14A shows the same image analysis performed in Figure 13A, except that the image analysis is performed on the image in Figure 11B. As shown in Figure 14A, first, the background is subtracted from the initial image 1402 (i.e., the image in Figure 11B) to obtain image 1404. Next, image 1404 can be denoised and filtered to obtain image 1406. Finally, image 1406 is normalized to obtain image 1408. Figure 14B is an image intensity diagram created in the same manner as in Figure 13B. In the case of the image in Figure 11B, the resulting frame statistic is 141, which falls within the target frame statistic range of 80-150 (when normalized to a range of 0-255). Therefore, the decision made in step S710 is "YES" that interference fringes are present. Similarly, in step S608, it is determined that the predetermined light conditions are met. Furthermore, since the frame statistic is less than 150, it is determined that the template is not yet in contact with the substrate. In alternative embodiments, a cropping step may be included so that the image analysis for obtaining the frame statistic uses only pixels known to be within the partial field. When the frame statistic is low, the detected position of the ICP tends to be dominated by background noise and tends to be towards the center of the image or the cropped image.

[0105] A "YES" answer in S710 causes Method 700 to proceed to step S714, where the estimated ICP is determined from the interference fringes. This is also step S610 of Method 600, where the estimated ICP is determined based on the detected light intensity. More specifically, the ICP is determined from the light intensity data representing the interference fringes. As mentioned above, as shown in the figure, the interference fringes appear in the form of concentric circles. The estimated ICP is the center of the concentric circles. Therefore, standard analytical tools can be used to find the center of the circles. Once the center of the circle of the interference fringe is determined, the estimated ICP is known. Step S610 may include calculating a weighted average using the rescaled DC-removed image 1308. The applicant has found that strong fringe intensities are set to higher values ​​and are therefore weighted more heavily than the background values ​​in the normalized image 1308. This estimation of the ICP is very accurate when the fringes are strong enough but do not form connecting lines. A proximity suitable for ICP determination can be determined (using the weighted average method) based on the predicted ICP location. Scanning only around the predicted ICP location on the normalized image 1308 indicates that the signal intensity is sufficiently strong (i.e., the frame statistics are sufficiently high) when the median of the pixels is greater than the center of the rescaled range of the image, stopping the template's movement toward the substrate and setting the contact control value V iApply the correction. Another way to perform step S610 is to use a circle search type analysis (e.g., the HoughCircles() function from the Open Source Computer Vision library). There are several well-known methods for finding circles in an image. Figure 14 shows the estimated ICP in the x and y directions for the frames of Figure 13C. Figure 13C shows the estimated ICP represented by target crosshairs superimposed on the normalized image 1308 for each frame. As shown in Figure 13C, the estimated ICP is difficult to identify until the frame statistics are shown to be sufficiently good, compared to frames 5-7, where the ICP estimates are very low. Figure 14 also shows that when the frame statistics exceed a threshold, it is a strong indicator that the frame provides a good estimate of the ICP, and that the estimated ICP can be done with minimal calculations and that the ICP can be estimated before contact.

[0106] Figures 12A and 12B show exemplary moments in which the distance d1 is further reduced compared to the moments in Figures 11A and 11B. While moment t5 in Figures 11A and 11B serves as one example in which interference appears and can be analyzed to obtain appropriate frame statistics, Figures 12A and 12B show another exemplary moment t7 in which appropriate frame statistics are also obtained. That is, multiple images K can satisfy process S710 and enable the determination of the estimated ICP. a And there are multiple distances d1. Figure 12B is an exemplary image K a (d1(t7)) is shown, where interference fringes 1202 within region 1204 become more visible, and the frame statistics are low enough that they are at the upper end of an acceptable range, but contact has not yet occurred. Therefore, image K in Figure 12B a For (d1(t7)), S710 is also "YES", and the estimated ICP can be used from this exemplary image as well. In one embodiment, if the frame statistics are too high, it may indicate that contact has occurred or is about to occur.

[0107] After obtaining the estimated ICP, method 700 proceeds to step S716, where it is determined whether the estimated ICP from step S714 is within a predetermined threshold of the target ICP. The predetermined threshold is predetermined based on the target ICP determined above, and corresponding control parameters are set during distance reduction to control the state of the template and / or substrate. The predetermined threshold is the allowable deviation from the target ICP. That is, if the estimated ICP is within the predetermined threshold, the estimated ICP is close enough to the target ICP to achieve adequate filling performance. On the other hand, if the estimated ICP is outside the predetermined threshold, the estimated ICP is too far from the target ICP to achieve adequate filling performance. The predetermined threshold may be determined by the accuracy requirements of the estimated ICP and the time required to estimate the ICP and stop the template's movement before it contacts the substrate. The predetermined threshold may be 80 to 149 when the image is normalized to 0 to 255.

[0108] If the estimated ICP is within a predetermined threshold (yes in step S716), method 700 proceeds to step S718, where the distance d1 continues to decrease and contact between the template and the substrate progresses. That is, when the estimated ICP is sufficiently close to the target ICP, the imprint proceeds using initial control parameters that set the state of the template and / or substrate until contact occurs. On the other hand, if the estimated ICP is outside the predetermined threshold (no in step S716), method 700 proceeds to step S720, where the distance d1 is increased. That is, if the estimated ICP is too far from the target ICP, instead of continuing the imprint process, the distance d1 between the template and the substrate is increased so that the template and the substrate are further apart than in the previous step. This is because if the estimated ICP is too far from the target ICP, the resulting imprint quality will be adversely affected by unacceptable filling. By increasing the distance d1 and then performing the subsequent steps discussed herein, the estimated ICP can be corrected to be sufficiently close to the target ICP. Increasing the distance d1 can be done by moving one or both of the template and the substrate away from the other.

[0109] After increasing the distance d1, method 700 may proceed to step S722, in which the control parameters are updated. That is, one or more of the control parameters used to control the state of the template and / or substrate are changed. Exemplary control parameters that may be changed in step S722 are the same parameters as above, for example, the radius of curvature R of the template. T Cavity pressure P for controlling T Radius of curvature R of the substrate S Substrate pressure P for controlling Sa , P Sb , P Sc ; template slope θ Tx and θ Ty The choice of which parameters to change and by how much may be based on the difference between the estimated ICPs determined in step S716. The difference between the estimated ICP and the target ICP can be quantified in terms of both magnitude (i.e., how far apart they are) and direction (i.e., whether the estimated ICP is closer to or further from the wafer center than the target ICP). If the estimated ICP is closer to the wafer center than the target ICP, the change to the control parameter is the cavity pressure P T Increase in substrate pressure P Sa , P Sb , P Sc Reduction of, and template tilt θ Tx and θ Ty This can be one or more (including all) of the following reductions. In cases where the estimated ICP is further from the wafer center than the target ICP, the change in the control parameter is the cavity pressure P T Decrease in substrate pressure P Sa , P Sb , P Sc The increase in the template tilt θ, as well as the template tilt θ Tx and θ TyIt can be one or more (including all) of the following increases. The magnitude of the change in the control parameter may be based on the magnitude of the difference in position between the estimated ICP and the target ICP. That is, the larger the difference between the estimated ICP and the target ICP, the greater the amount of adjustment required for the control parameter. For example, if the change in cavity pressure is 1 kPa, the change in the position of the ICP can be expected to be about 1 mm, depending on the molding system and template 108. A 1 kPa change in substrate pressure can change the position of the ICP by about 0.8 mm, depending on the position of the vacuum control zone of the substrate chuck 104 relative to the position and shape of the partial field. Prior experimental tests can be conducted to correlate how much each change in control parameter affects the ICP. Thus, using this predetermined correlation information, it is possible to determine which control parameter should be changed and by how much the selected control parameter should be changed. Template tilt θ Tx Adjusting this can be used to adjust the position of the ICP in the y direction, and tilt θ Ty Adjusting this can be used to adjust the position of the ICP in the x-direction.

[0110] The process of changing the control parameters described above corresponds to step S612 of method 600. That is, in step S612, if the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, the state of the template and / or substrate is changed based on that difference.

[0111] As shown in Figure 7, after updating one or more control parameters in step S722, the process starting from step S706 is repeated. The difference in the second cycle is that the control parameters have been changed and the state of the template and / or substrate has been changed. Thus, the same steps S706-S714 are repeated to reach a new estimated ICP. This process involves again decreasing the distance d1 between the template and the substrate while capturing and analyzing images of interference fringes. As previously stated, following method 700, the new / updated estimated ICP is finally determined. If the new estimated ICP is within a predetermined threshold of the target ICP (the target ICP remains constant), method 700 ends in step S718 with a second cycle, completing the imprint. If the new estimated ICP is still too far from the target ICP, the cycle is repeated again. However, it has been found that by using method 700, which involves changing the control parameters based on the magnitude and direction of the difference between the target ICP and the estimated ICP, it is sufficient to update the control parameters only once to achieve an estimated ICP that is within a predetermined threshold distance from the target ICP.

[0112] Figure 15A is a timing diagram showing how the template cavity pressure control conditions change over time in an exemplary embodiment for imprinting a partial field and a small partial field. Figure 15B shows the position of the template chuck (z) at the same time as in Figure 15A. T This diagram shows how to adjust the template chuck position (z). T ) correlates with the first distance d1. Figure 15B also shows how the frame statistics change over time. Figures 15A and 15B also show the initial contact time (t IC Figure 15A shows when the template cavity pressure (P) reaches [value missing]. T ) is the initial template cavity pressure (P T1 ) is adjusted, and then the initial contact time (t IC Before ) adjust pressure (P A This is a timing diagram showing how the adjustment pressure (P) is adjusted.A ) represents the change in the control parameters described above with respect to S722. As shown in Figures 15A and 15B, from the initial time to time t a Until then, the template chuck position remains unchanged, and the template cavity pressure is the initial pressure P. T1 It rises up to the initial template cavity pressure P. T1 This embodiment, which reaches [time t], corresponds to step S704. Therefore, time t a This corresponds to the completion of process S704 and the start of process S706.

[0113] Next, as shown in Figure 15B, the template position descends. This corresponds to process S706. This occurs at time t b The process proceeds until it reaches time t, during which time steps S708~S716 are performed to analyze the image. b When it reaches the template chuck position (z T ) is a template with template cavity pressure P T new pressure P A During process S720, the template rises until it reaches a safe position that increases up to a certain point. The rise in the template position corresponds to process S720, and the increase in pressure corresponds to process S722, P A This indicates adjusting the control parameter for the template cavity pressure. For simplicity, only the template cavity pressure is shown, but other control parameters mentioned above may be adjusted as described above when it is necessary to adjust the estimated ICP. Alternatively, the template chuck position (z T ) is the template cavity pressure (P T ) may be changed while increasing. The reference image of the background only at time t0 is the template cavity pressure (P T ) is the initial template cavity pressure (P T1This is obtained after reaching t0. Alternatively, a background-only reference image may be acquired in a preliminary stage before the molding process or at an early stage during the molding process. In an alternative embodiment, the background-only reference image may be a simulated image. The substrate chuck can continue fine alignment on the micron and submicron scales after time t0.

[0114] Figure 15B shows the elapsed time t c Following this, the template position is shown to descend again. This corresponds to the second execution of S706. Once the template begins to descend, the same process S708-S716 is repeated. In the exemplary embodiment shown in Figures 15A and 15B, after adjusting the template cavity pressure once, the estimated ICP is within the threshold, and the timing chart shows the initial contact time t IC Proceed to the next step. Initial contact time t IC During and after this period, the same imprinting process and control of control parameters as described in the documents incorporated herein are performed. That is, after the template and substrate come into contact, the same imprinting process as described in U.S. Patent No. 11,614,693 is performed. See, for example, Figures 9A-9G and their corresponding descriptions in U.S. Patent No. 11,614,693. The image in Figure 12B shows the initial contact time t, which can be recognized by the non-circularity of the interference fringes and the increase in frame statistics. IC It was obtained afterwards.

[0115] By implementing the above method, it is possible to achieve an actual ICP closer to the target ICP than by proceeding to contact without implementing the above method. In other words, if imprinting is performed using initial control parameters without implementing the above method, the actual ICP may be too far from the target ICP, potentially resulting in poor filling. The above method minimizes or avoids such situations. Therefore, products / articles manufactured according to the above method also have superior quality as a result of superior filling.

[0116] By considering this description, further modifications and alternative embodiments of various aspects will become apparent to those skilled in the art. Therefore, this description should be interpreted as illustrative only. It should be understood that the forms shown and described herein should be interpreted as examples of embodiments. Elements and materials may be substituted with those illustrated and described herein, parts and processes may be reversed, and certain features may be used independently, all of which will be apparent to those skilled in the art after enjoying the benefits of this specification.

Claims

1. A process to reduce the distance between the template and the substrate, While the aforementioned distance is being reduced, A step of controlling the state of one or more of the template and the substrate, A step of detecting the light intensity of light reflected from both the template and the substrate, A step of determining whether predetermined light conditions have been met based on the detected light intensity, If it is determined that the predetermined light conditions are met, the process involves determining the estimated initial contact point between the template and the substrate based on the detected light intensity. If the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, the process of changing the state based on the difference is performed. An imprinting method characterized by having the following features.

2. The imprint method according to claim 1, characterized in that if the difference is less than or equal to the predetermined threshold, the distance is further reduced without changing the state.

3. The imprint method according to claim 2, characterized in that the distance is further reduced without changing the state until the template and the substrate come into contact.

4. The imprint method according to claim 1, wherein if it is determined that the predetermined light conditions are not met, the detection of light intensity is repeated until the predetermined light conditions are met, and the determination of whether or not the predetermined light conditions are met is repeated.

5. The imprint method according to claim 1, characterized in that if the difference is less than the predetermined threshold, the distance is increased.

6. The imprint method according to claim 5, characterized in that after increasing the distance, the distance is decreased again while maintaining the modified state.

7. While the aforementioned distance is decreasing again, The light intensity of the light reflected from both the template and the substrate is detected. Based on the detected light intensity, it is determined whether the predetermined light conditions are met. If it is determined that the predetermined light conditions are met, the updated estimated initial contact point between the template and the substrate is determined based on the detected light intensity. If the difference between the updated estimated initial contact point and the target initial contact point is less than or equal to the predetermined threshold, the template and the substrate are brought into contact. The imprinting method according to feature 6.

8. The imprint method according to claim 1, characterized in that one or more of the states of the template and the substrate are controlled based on control parameters.

9. The imprint method according to claim 8, characterized in that the control parameter is a parameter selected from the group consisting of template cavity pressure, substrate pressure, and the inclination of the template.

10. The imprint method according to claim 9, characterized in that the template cavity pressure controls the radius of curvature of the template, and the substrate pressure controls the radius of curvature of the substrate.

11. The imprint method according to claim 1, characterized in that the predetermined light condition is the presence of interference fringes caused by light reflected from both the template and the substrate.

12. The imprint method according to claim 11, characterized in that the predetermined light conditions are based on a predetermined range of frame statistics.

13. The process further includes determining frame statistics from the detected light intensity of light reflected from both the template and the substrate, The imprint method according to claim 12, characterized in that the step of determining whether the predetermined light conditions are met is performed by determining whether the determined frame statistics fall within the predetermined range of the frame statistics.

14. The aforementioned template has a molding surface, While the aforementioned distance is being reduced, the molded surface overlaps with the edge of the substrate. The imprinting method according to feature 1.

15. The molded surface overlaps with the edge of the substrate by an amount of overlap. The target initial contact point is determined based on the amount of overlap. The imprint method according to feature 14.

16. The process further includes emitting visible light toward the template and the substrate while the aforementioned distance is being reduced. The light reflected from both the template and the substrate is the emitted visible light. The imprinting method according to feature 1.

17. A method for manufacturing articles, A process of dispensing moldable material onto a substrate, A step of reducing the distance between the template and the substrate, While the aforementioned distance is being reduced, A step of controlling the state of one or more of the template and the substrate, A step of detecting the light intensity of light reflected from both the template and the substrate, A step of determining whether predetermined light conditions have been met based on the detected light intensity, If it is determined that the predetermined light conditions are met, the process involves determining the estimated initial contact point between the template and the substrate based on the detected light intensity. If the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, the process of changing the state based on the difference is performed. A step of bringing the template into contact with the moldable material, A step of exposing the moldable material beneath the template with a chemical beam, The process of processing the aforementioned substrate, A step of forming the article from the processed substrate, A method characterized by having the following:

18. One or more memory devices, Includes one or more processors, and the one or more processors A step of reducing the distance between the template and the substrate, While the aforementioned distance is being reduced, A step of controlling the state of one or more of the template and the substrate, A step of detecting the light intensity of light reflected from both the template and the substrate, A step of determining whether predetermined light conditions have been met based on the detected light intensity, If it is determined that the predetermined light conditions are met, the process involves determining the estimated initial contact point between the template and the substrate based on the detected light intensity. If the difference between the estimated initial contact point and the target initial contact point is greater than a predetermined threshold, the process of changing the state based on the difference is performed. An imprint system characterized by performing the following:

Images