Fixture and associated imprint system and method

Abstract

A fixture and related systems and methods are disclosed. According to one implementation, the method includes applying a resin (124) onto a substrate (122) and positioning the substrate on a chuck (110) of a base (108) of the fixture (104). The method also includes moving a mold (118) to engage the resin and curing the resin. The method also includes separating the mold and the resin and determining a separation force applied as a function of a separation distance between the mold and the resin during separation of the mold and the resin.

Description

Technical Field

[0001] (Related Application) This application claims the benefit and priority of U.S. Patent Provisional Application No. 63 / 073,423, filed on September 1, 2020, the entire content of which is incorporated herein by reference for all purposes.

Background Art

[0002] Patterned flow cells and / or microarrays can be produced using semiconductor manufacturing techniques. In some cases, parts produced using nanoimprint lithography may have defects that can be identified during quality control procedures.

Summary of the Invention

[0003] The disadvantages of the prior art can be overcome, and the benefits described hereinafter in the present disclosure can be achieved through the provision of the fixtures and related systems and methods described herein. Various embodiments of the apparatus and method are described below, and the apparatus and method, including and excluding the additional implementation forms listed below, in any combination (provided that these combinations are not contradictory), can overcome these disadvantages and achieve the advantages described herein.

[0004] One parameter found to affect defects in parts produced using nanoimprint lithography is the amount of force used to separate the mold from the cured resin during the demolding procedure. To identify which resins, designs, and / or separation rates require less separation force during the demolding procedure, at least one aspect of this disclosure relates to a benchtop test fixture for use with nanoimprint lithography and related systems and methods. Advantageously, the test fixture can be used to perform experiments to determine the separation force applied to the mold when separating it from the cured resin. Thus, operators can test different demolding processes, different patterns, and / or different resins in small-scale or one-off productions to determine which demolding processes, and / or resins result in fewer defects and / or lower separation forces. More generally, the disclosed test fixture enables operators to make more informed decisions when creating custom separation rate profiles, custom resins, and / or custom nanopattern arrays. Furthermore, the disclosed test fixtures allow parameters to be rapidly changed and tested, enabling the identification of those parameters associated with fewer product defects without involving changes to semiconductor manufacturing equipment on a production scale.

[0005] The separation force can be expressed as a function of the separation distance between the mold and the cured resin. Furthermore, using a test fixture, the total separation work, represented by the separation work and / or the area under the force-distance curve, can be determined. Using the disclosed implementation, molds fabricated to have different nanopattern densities, dimensions, and / or periodicities can be tested with different resin compositions and / or release procedures to identify which molds, resin compositions, and / or molding procedures have lower separation forces.

[0006] In some implementations, the test fixture includes a base on which a substrate is placed and which has a vacuum chuck with a support hinged to the base. The support has a mold support receptacle that receives a mold support that holds the mold. The mold may be referred to as a working stamp.

[0007] To produce a nanopatterned array using the disclosed implementation, a resin is spin-coated onto a substrate, and the support is rotated toward the base to engage the mold with the resin. The resin is cured, and the mold and cured resin are separated using a drive assembly attached to a load cell. As the drive assembly moves the load cell and the mold and the resin separates from each other, the load cell determines the force applied to the mold, and the corresponding system determines the force applied to the mold as a function of the separation distance between the mold and the resin. In some implementations, the separation distance is the vertical distance traveled by the edge of the support attached to the load cell. By comparing the separation forces of different resins, a lower separation force can be identified, thereby allowing for the selection of a process to produce a working stamp and / or nanopatterned array with a resin, design, and / or separation rate, and / or fewer defects.

[0008] According to the first implementation form, the method includes applying a resin onto a substrate and positioning the substrate on a chuck on the base of a fixture. The method also includes moving a mold to engage with the resin and curing the resin. The method also includes separating the mold from the resin and determining a separation force to be applied as a function of the separation distance between the mold and the resin while separating the mold from the resin.

[0009] According to the second implementation, the device includes a fixture comprising 1) a base having a chuck, and 2) a support that is hinged to the base and includes a mold support receptacle. The support is connectable to a load cell.

[0010] According to the third implementation, the device includes a system comprising a load cell, a fixture, and a mold support. The fixture includes 1) a base including a chuck, and 2) a support hinged to the base and including a mold support receptacle, the mold support being received within the mold support receptacle. The support is connectable to the load cell.

[0011] Furthermore, according to the first, second, and / or third embodiments described above, the apparatus and / or method may further include one or more of the following:

[0012] According to one implementation configuration, the method includes fixing a mold within a mold support and connecting the mold support to a support of a fixing device.

[0013] According to another implementation, the method involves hinge-connecting the support and the base of the fastener.

[0014] According to another implementation, the method involves changing the hinge point between the support and the base between a first position and a second position.

[0015] According to another implementation, changing the hinge point involves moving the hinge point away from the plane defined by the mold or mold support.

[0016] According to another implementation, the method includes connecting the support and the load cell, and separating the mold and the resin includes separating the mold and the resin while the support is connected to the load cell.

[0017] In another implementation, connecting the support and the load cell involves clamping a strap at the end of the support and connecting the strap to the load cell.

[0018] According to another implementation, clamping the strap involves closing the clamp at the end of the support.

[0019] According to another implementation form, the strap includes a zip tie.

[0020] According to another implementation form, engaging the mold and the resin includes rotating the mold support toward the base of the fixture.

[0021] According to another implementation form, the method includes using a vacuum to draw a substrate toward a chuck.

[0022] According to another implementation form, the support includes a support bracket, and the base includes a base bracket hingedly connected to the support bracket.

[0023] According to another implementation form, each of the support bracket and the base bracket includes an L-shaped bracket.

[0024] According to another implementation form, the hinge point between the support bracket and the base bracket is spaced from the plane defined by the support.

[0025] According to another implementation form, the base bracket includes a plurality of connection holes that enable the hinge point between the support and the base to vary between a first position and a second position.

[0026] According to another implementation form, the support is rectangular and includes corner supports at each corner of the support.

[0027] According to another implementation form, the base includes a port fluidly connected to a chuck.

[0028] According to another implementation form, an end of the support includes a clamp that can be connected to a load cell via a strap.

[0029] According to another implementation form, the apparatus includes an unpatterned foil connected within a mold support, a master template positioned on a chuck, and a resin disposed on the master template.

[0030] According to another implementation form, the device includes a mold connected within a mold support, a substrate positioned on a chuck, and a resin disposed on the substrate.

[0031] According to another implementation form, the mold is movable to engage with the resin and is curable, and the load cell is connected to the support so as to determine the separation force when the mold and the resin are separated.

[0032] According to another implementation form, the load cell determines the force applied to the support, and the system determines the force applied to the support as a function of the separation distance between the mold and the resin.

[0033] According to another implementation form, the device includes a set screw for connecting the mold support within the mold support receptacle.

[0034] According to another implementation form, the chuck is a vacuum chuck.

[0035] All combinations of the foregoing concepts and additional concepts, to be considered in more detail below (if such concepts are not mutually inconsistent), are considered to be part of the subject matter of the invention disclosed herein and may be implemented in any combination to achieve the benefits described herein. Specifically, all combinations of the claimed subject matter that appear at the end of this disclosure are intended to be part of the subject matter of the invention disclosed herein and may be implemented in any combination to achieve the advantages described herein.

Brief Description of the Drawings

[0036] [Figure 1] It is a schematic diagram of an implementation form of a system according to the teachings of this disclosure. [Figure 2] It is a schematic diagram of another implementation form of the system of FIG. 1A. [Figure 3] It is a schematic diagram of the fixture of FIG. 2. [Figure 4]This is an isometric section enlargement of the mounting configuration of the mold transport fixture and mold support that can be used with the system shown in Figure 1. [Figure 5] This is another implementation of the fastener that can be used with the system shown in Figure 1. [Figure 6] Figure 1 shows a side view of the system's implementation configuration. [Figure 7] Figure 6 shows a side view of the system used to separate the mold from the cured resin. [Figure 8] A flowchart illustrating an exemplary method for determining the separation force during the demolding procedure disclosed herein is shown. [Figure 9] Another flowchart illustrating an exemplary method for determining the separation force during the demolding procedure disclosed herein is shown. [Figure 10] Another flowchart illustrating an exemplary method for determining the separation force during the demolding procedure, as disclosed herein, is shown. [Figure 11] This graph shows test results using an exemplary system disclosed herein. [Figure 12] This graph shows test results using an exemplary system disclosed herein. [Modes for carrying out the invention]

[0037] The following text discloses detailed descriptions of implementations of the method, apparatus, and / or product, but it should be understood that the legal scope of ownership is defined by the claims set out at the end of this patent. Therefore, the following “Modes for Carrying Out the Invention” should be interpreted as illustrative only and do not describe all possible implementations, as it would be impractical, if not impossible, to describe all possible implementations. Numerous alternative implementations may be implemented using either the current art or art developed after the filing date of this patent. Such alternative implementations are expected to still fall within the scope of the claims.

[0038] Figure 1 shows a schematic diagram of one implementation of System 100 in accordance with the teachings of this disclosure. System 100 may be used to perform testing against different resins when producing prototypes, patterned flow cells, microarrays, and / or associated work stamps using nanoimprint lithography and / or semiconductor manufacturing techniques. In the shown implementation, System 100 may be a benchtop system for an offline imprint process and includes a load cell 102 and a drive assembly 103 used during the demolding procedure. System 100 also includes a fixture 104 used to produce a work stamp and / or nanopatterned array and controller 106. The controller 106 is electrically and / or communicatively connected to the load cell 102, the drive assembly 103, and / or the fixture 104 and is adapted to cause the load cell 102, the drive assembly 103, and / or the fixture 104 to perform various functions disclosed herein.

[0039] In the shown configuration, the fixture 104 includes a base 108 having a chuck 110 and a support 112 connected to the base 108 via a hinge, so that the chuck 110 and the support 112 are hinged together. The support 112 also includes a mold support receptacle 114. The mold support 116 is received within the mold support receptacle 114 and can hold a mold 118 having a pattern 120. The pattern 120 may include feature portions having dimensions of about 10 nanometers to about 3 micrometers or equal to and can be used to form wells in a flow cell. For example, some of the feature portions on the pattern 120 may have dimensions of about 200 nanometers to about 300 nanometers or equal to. More generally, the dimensions of one or more features on pattern 120 may be about 10 nanometers to about 100 nanometers or equal thereto, about 100 nanometers to about 1,000 nanometers or equal thereto, and / or about 1,000 nanometers to about 10,000 nanometers or equal thereto. However, features on pattern 120 may be of different sizes.

[0040] The mold support 116 is fixed within the support 112 via fasteners 121 such as set screws, and the mold 118 is fixed to the mold support 116 via mold clamps 202 (see Figure 4). The mold 118 may be referred to as a work stamp.

[0041] To produce a nanoimprint array, the substrate 122 is positioned on the chuck 110, and the resin 124 is placed on the substrate 122. The substrate 122 may be directly or indirectly on the chuck 110. Before engaging the mold 118 with the resin 124, the resin 124 can be heated to remove any residual solvent. The resin 124 may be applied as a thin film having a thickness of about 1 μm or less. However, other materials and / or thicknesses may also be preferred. For example, the thickness of the resin 124 may be about 200 nanometers or less, about 400 to about 500 nanometers or equal to them, about 1.5 μm to about 2.0 μm or equal to them, and / or about 10 μm or less. More generally, the thickness of the resin 124 may be about 200 nanometers to about 2,000 nanometers or equal to them.

[0042] To imprint the pattern 120 from the mold 18 onto the resin 124, the mold 118 is moved toward the resin 124 via the support 112 so that the mold 118 engages with and presses against the resin 124 and the resin 124 is cured. The mold 118 is pressed into the resin 124 using a hand roller or another leveling device, and capillary forces between the resin 124 and the mold 118 can keep the mold 118 in contact with the resin 124. Alternatively, the drive assembly 103 can move the mold 118 to engage with the resin 124. The system 100 may include an ultraviolet light source for curing the resin 124 in ultraviolet (UV) nanoimprint lithography, and / or the system 100 may include a heating / cooling source for curing the resin 124 in thermal nanoimprint lithography. Alternatively, the fixture 104, the substrate 122, and the resin 124 can be removed from the system 100, and the resin 124 can be cured in an area outside the system 100.

[0043] Regardless of how the resin 124 cures, during the demolding procedure, the load cell 102 is connected to the support 112 via a connector 126. The connector 126 may be a strap or zip tie and may be secured to the load cell 102 using a gripper 127 and to the support 112 using a clamp 128. The clamp 128 may be formed between the block 129 and the support 112 and may be movable between clamp positions via a fastener 130. To secure the connector 126 and the support 112, the fastener 130 is loosened, the connector 126 is positioned between the block 129 and the support 112, and the fastener 130 is tightened to secure the connector 126 within the clamp 128.

[0044] Regardless of how the load cell 102 is attached to the support 112, after the load cell 102 is attached to the support 112, the drive assembly 103 moves the load cell 102 in the direction generally indicated by arrow 131 to separate the mold 118 and the cured resin 124. As the mold 118 is moved by the support 112 through its attachment to the load cell 102, the support 112 prevents the mold 118 from rotating as the mold 118 is separated from the cured resin 124. The drive assembly 103 can move the load cell 102 at a variable speed and / or pause the load cell 102 in between movements. As a result, a separation speed of resin 124 with higher product quality (fewer defects) and therefore less scrap is selected. Some of the speeds at which the drive assembly 103 can move the load cell 102 include about 10 millimeters (mm) / minute (min), about 50 mm / min, and / or about 100 mm / min. Other speeds may also be suitable.

[0045] While the mold 118 is moved away from the resin 124, the load cell 102 determines the force applied to the support 112, and the system 100 determines the force applied as a function of the separation distance between the mold 118 and the resin 124. In some implementations, the system 100 is a force and torque measuring system such as the Instron® 3342B universal test system. However, other test machines may be used. Additionally or alternatively, the system 100 can determine the separation work and / or total separation work, which is represented by the region below the force-distance curve. Different resin 124 compositions, resin 124 curing conditions, and / or mold 118 patterns 120 can vary the amount of separation force and / or the amount of separation work. Several additional parameters that may affect the separation force and / or separation operation include the thickness of the mold 118, the type of mold 118 used, the tension of the mold 118, the concentration of the leveling agent in the resin 124, the UV curing intensity, the UV curing time, the material used for the mold 118, the mechanical properties of the mold 118, the curing rate of the resin 124, and / or the anti-tack layer used in conjunction with the master template during the production of the mold 118, and / or the anti-tack layer applied to the mold 118. The anti-tack layer may include any suitable material (e.g., polymer materials, monomers, monolayers) and can be applied to the master template, for example, to reduce adhesion between the master template and the resin 124 during the demolding procedure. By monitoring the parameters affecting the separation force and / or separation operation using the system 100, it is possible to produce parts using parameters and / or resin 124 that have a lower separation force and / or are associated with less separation operation.

[0046] Further referring to the system 100 and the fixture 104, in the shown configuration, the system 100 includes a base plate 132, and the base 108 of the fixture 104 is connected to the base plate 132 via fasteners 133. The base plate 132 may be a breadboard, and the fasteners 133 may be wing nuts that allow the fixture 104 to be connected to and disconnected from the system 100 relatively easily. For example, the fixture 104 may be connected to the system 100 during the demolding procedure when the substrate 122 and resin 124 are applied to the chuck 110, but the fixture 104 may be removed from the system 100 when the resin 124 is curing. Furthermore, the fasteners 133 allow the fixture 104 to be easily attached to or removed from the system 100, and as a result, one or more preliminary measurement processes can be performed on the fixture 104.

[0047] The chuck 110 includes a surface 134 that receives the substrate 122 and is fluidly connected to a port 135 of the base 108 via a fluid line 136. The system 100 includes a vacuum pump 138 connected to the port 135 and providing a suction force to hold the substrate 122 on the chuck 110. The vacuum pump 138 can be operated to fix the substrate 122 to the chuck 110 when the resin 124 is applied to the substrate 122, when the mold 118 engages with the resin 124, and / or when the mold 118 separates from the cured resin 124.

[0048] Referring to the base 108 and the support 112, in the shown configuration, the base 108 and the support 112 are hinged to each other via a pair of hinges 140 formed by a pair of base brackets 142 of the base 108, a pair of support brackets 144 of the support 112, and pins 146 that are received within the brackets 142, 144 and connect the brackets 142, 144 together. In the shown configuration, the base bracket 142 defines a plurality of connecting holes 148 that can be aligned with the corresponding connecting holes 150 of the support brackets 144. By inserting the pins 146 into different connecting holes 148, 150, it is possible to change the hinge point between the support 112 and the base 108, for example, between a first position and a second position. Different hinge points can change the amount of leverage that the support 112 provides during the demolding procedure. While the base bracket 142 is shown to include a plurality of connecting holes 148, in other mounting configurations, the support bracket 144 may include an additional or alternative plurality of connecting holes 150.

[0049] While the above example refers to the use of system 100 for producing and testing nanopattern arrays, system 100 can similarly be used to produce and test molds 118, as will be discussed in more detail in Figure 10. In such an implementation, to produce mold 118, a master template is placed on a chuck 110 and an unpatterned foil is bonded to a mold support 116. An anti-tack layer may be applied to the master template to reduce adhesion between the master template and the resin 124, the resin 124 is applied to the master template, and the unpatterned foil is laminated on the resin 124 to produce mold 118, called a working stamp. By applying the resin 124 to the master template, the resin 124 can be filled into the nanopattern array defined by the master template.

[0050] Referring to the controller 106, in the illustrated implementation, the controller 106 includes a user interface 152, a communication interface 154, one or more processors 156, and a memory 158 that stores instructions executable by one or more processors 156 for performing various functions, including the disclosed implementation. The user interface 152, the communication interface 154, and the memory 158 are electrically and / or communicatively connected to one or more processors 156.

[0051] In its implementation, the user interface 152 is adapted to receive input from the user and provide the user with information associated with the operation of the system 100 and / or the analysis performed. The user interface 152 may include a touchscreen, display, keyboard, speaker, mouse, trackball, and / or voice recognition system. The touchscreen and / or display may show a graphical user interface (GUI).

[0052] In the implementation, the communication interface 154 is adapted to enable communication between system 100 and a remote system (e.g., a computer) over a network. Examples of networks include the internet, intranet, local area network (LAN), wide area network (WAN), coaxial cable network, wireless network, wired network, satellite network, digital subscriber line (DSL) network, cellular network, Bluetooth connection, and near-field communication (NFC) connection. Some of the communication provided to the remote system may be associated with analysis results, test data, etc., generated by system 100 or acquired by other means. Some of the communication provided to system 100 may be associated with test operations, semiconductor manufacturing techniques, and / or protocols performed by system 100.

[0053] One or more processors 156 and / or system 100 may include one or more processor-based systems or microprocessor-based systems. In some implementations, one or more processors 156 and / or system 100 may include one or more programmable processors, programmable controllers, microprocessors, microcontrollers, graphics processing units (GPUs), digital signal processors (DSPs), reduced-instruction-set computers (RISCs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), field-programmable logic devices (FPLDs), logic circuits, and / or other logic-based devices that perform various functions, including those described herein.

[0054] Memory 158 includes semiconductor memory, magnetically readable memory, optical memory, hard disk drives (HDDs), optical storage drives, solid-state storage devices, solid-state drives (SSDs), flash memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), random-access memory (RAM), non-volatile RAM (NVRAM), compact discs (CDs), compact disc read-only memory (CD-ROMs), digital versatile discs (DVDs), Blu-ray discs, and redundant arrays of independent discs. This may include one or more of the following storage devices or storage disks: disks, RAID systems, caches, and / or any other storage devices or storage disks on which information is stored for any duration (e.g., permanently, temporarily, over a long period, for buffering, for caching).

[0055] Figure 2 shows a schematic diagram of another implementation of system 100 of Figure 1A. In the implementation shown, system 100 includes a load cell 102, a fixture 104, and a mold support 116. Similar to system 100 in Figure 1, the fixture 104 in Figure 2 includes a base 108 having a chuck 110, and a support 112 hinged to the base 108 and including a mold support receptacle 114. The mold support 116 is shown disposed within the mold support receptacle 114, and the support 112 is shown connected to the load cell 102 via a connector 126 to allow the load cell 102 to determine the separation force between the base 108 and the support 112.

[0056] Figure 3 is a schematic diagram of the fixture 104 of Figure 2, but without the mold support 116. In the shown configuration, the fixture 104 includes a base 108 having a chuck 110, and a support 112 hinged to the base 108 and including a mold support receptacle 114. The support 112 is connectable to a load cell 102 and determines the separation force between the base 108 and the support 112.

[0057] Figure 4 is an isometric section enlargement of an assembly configuration of a fixing device 104 and a mold support 116 for carrying a mold 118, which can be used with the system of Figure 1. Referring to the base 108 of the fixing device 104, in the shown assembly configuration, the base 108 includes a central portion 160 that surrounds the chuck 110 and defines a threaded hole 162 and an L-shaped side wall 164. The fastener 130 engages threadably with the threaded hole 162, and the central portion 160 and the side wall 164 form a receptacle 166 having a front opening 168 and a rear opening 170. In the closed position (see Figure 5), the support 112 enters into the receptacle 166 of the base 108 and includes a pair of or rear notches 172, each receiving a corresponding portion 174 of the side wall 164. Although the side wall 164 is shown as L-shaped, in other assembly configurations the side wall 164 may be straight. Alternatively, the side wall 164 may be omitted.

[0058] In the shown configuration, the base 108 also defines lower notches 176, each receiving a leg 178 of the base bracket 142. The base bracket 142 is connected to the base 108 using fasteners 180. However, the base bracket 142 and the base 108 can be connected in different ways. Alternatively, the base bracket 142 and the base 108 can be a single unit.

[0059] The base bracket 142 and support bracket 144 are shown in Figure 4 as upward-facing L-shaped brackets 182 that allow the hinge point of the hinge 140 to be separated from the plane formed by the support 112, the mold support 116, and / or the mold 118. As a result of the hinge point being separated from the plane, the support 112, the mold support 116, and the mold 118 are moved upward and in the direction roughly indicated by the arrow 131 shown in Figure 1, so that the end of the support 112 opposite the hinge 140 can be raised substantially vertically. As described herein, the phrase “substantially vertical” means vertical at an angle of about 15 degrees or less. The flexibility of the connection 126 between the load cell 102 and the support 112 may additionally or alternatively allow the support 112 to be raised substantially vertically. The hinge 140 being separated from the plane relative to the mold 118 also allows the mold 118 not to make premature contact with the resin 124. Therefore, the mold 118 can be positioned at approximately 0.1 mm to approximately 0.8 mm before engaging with the resin 124. The lengths of the brackets 142 and 144 can also be changed to increase or decrease the lever force provided by the support 112 during the demolding procedure.

[0060] In the provided implementation, with reference to support 112, support 112 is rectangular and has side walls 184 that intersect at the corners 188 of support 112. Corner support 190 is connected to the side walls 184 at each of the corners 188 and together with the side walls 184 forms a mold support receptacle 114. When mold support 116 is received within the mold support receptacle 114, mold support 116 is placed on the corner support 190 and secured within the mold support receptacle 114 via fasteners 121.

[0061] Referring to the mold support 116, in the shown configuration, the mold support 116 is rectangular and has sides 192, 194, 196, and 198 that form the opening 200. In the shown configuration, the mold clamp 202 is connected to opposing sides 194, 198 by a spring 204. When using the mold support 116 to produce, for example, a nanopattern array, the mold 118 can be connected to and between the mold clamps 202. The spring 204 is used to maintain tension on the mold 118.

[0062] Although the mold support 116 is shown to include two mold clamps 202, the mold support 116 may alternatively include one mold clamp 202 connected to, for example, the distal side 194 of the mold support 116. Furthermore, although the mold support 116 is shown to include several springs 204 in a particular arrangement, any number of springs (e.g., 1, 2, 4) positioned in any arrangement can be used. In addition, although a single mold support is shown in Figure 4, any number of mold supports may be used together with fasteners 104, which may be similar to or different from each other.

[0063] Figure 5 shows another implementation of the fixture 104 that can be used with the system 100 of Figure 1. The fixture 104 of Figure 5 is at least substantially similar to the fixture 104 of Figure 4. In contrast, however, the base bracket 142 includes a plurality of connecting holes 148 that allow the connection point between the base 108 and the support 112 to vary in different positions. Although each of the base brackets 142 is shown to include nine connecting holes 148 in a particular arrangement, any number of connecting holes may be included in any arrangement of either bracket 142, 144.

[0064] Figure 6 shows a side view of the implemented configuration of system 100 of Figure 1. System 100 includes a system base 300, a column 302, and a head 304 that is movably mounted on the column 302 and carries a load cell 102. System 100 also includes legs 306 that extend from the system base 300 and are connected to a base plate 132 and a fixture 104.

[0065] Figure 7 shows a side view of the system 100 of Figure 6 separating the mold 118 from the cured resin 124. In the shown configuration, the first end 308 of the connector 126 is fixed within the gripper 127, and the second end 310 of the connector 126 is fixed within the clamp 128 of the support 112. During operation, the head 304 of the system 100 moves the load cell 102 in the direction roughly indicated by the arrow 312, the load cell 102 determines the force applied to the support 112, and the system 100 determines the resulting force with respect to the displacement profile of the resin 124 being measured.

[0066] Figures 8 to 10 show, for example, a flowchart for a method for determining the separation force during a demolding procedure disclosed herein. The execution order of the blocks may be changed, and / or parts of the described blocks may be modified, deleted, linked, and / or subdivided into multiple blocks.

[0067] The process in Figure 8 begins with the application of resin 124 to the substrate 122, for example, via a spin-coating technique (block 801). The substrate 122 is positioned on the chuck 110 of the base 108 of the fixture 104 (block 802). The substrate 122 may be glass, silicon, and / or silicon dioxide. However, the substrate 122 may be made from different materials. The support 112 and base 108 of the fixture 104 are hinged together (block 804), and the hinge point between the support 112 and the base 108 is changed between a first position and a second position (block 806). Changing the position of the hinge point changes the amount of leverage force provided by the support 112 when the support 112 is biased upward during the demolding procedure. In some implementations, the hinge point is positioned away from the plane defined by the mold 118 or mold support 116 to prevent the mold 118 from inadvertently engaging with the resin 124 before the resin 124 is molded.

[0068] The mold 118 is fixed within the mold support 116 (block 808). In some implementations, fixing the mold 118 within the mold support 116 includes connecting the mold 118 to a spring-biased mold clamp 202 that keeps the mold 118 in a tensile state. The mold support 116 is connected to the support 112 of the fixture 104 by, for example, nesting the mold support 116 within the support 112 to provide a secure connection between the mold support 116 and the support 112 (block 810).

[0069] To form the nanopattern array, the mold 118 is moved to engage with the resin 124 (block 814) and the pattern 120 is imprinted from the mold 118 into the resin 124. In some implementation configurations, engaging the mold 118 with the resin 124 involves rotating the mold support 116 toward the base 108 of the fixture 104. The resin 124 is cured using, for example, UV nanoimprint lithography (NIL) curing techniques and / or thermal NIL curing techniques (block 816).

[0070] To perform the demolding procedure, the support 112 is connected to the load cell 102 (block 818). In some implementations, connecting the support 112 to the load cell 102 involves clamping a connecting portion 126, formed as a strap, within a clamp 128 at the end of the support 112, and connecting the strap to the load cell 102 involves positioning the connecting portion 126 within the associated gripper 127. The connector 126 may also be a zip tie. However, other types of connectors may also be preferred.

[0071] The mold 118 and the cured resin 124 are separated from each other (block 820). In some implementations, the drive assembly 103 separates the mold 118 and the cured resin 124 by moving a load cell 102 attached to the support 112 away from the base 108 of the fixture 104. While the mold 118 and the resin 124 are separated, a separation force is determined that is applied as a function of the separation distance between the mold 118 and the resin 124 (block 822). In some implementations, the load cell 102 determines the force applied to the support 112, and the system 100 determines the force that is applied as a function of the separation distance between the mold 118 and the resin 124.

[0072] The process in Figure 9 begins with the resin 124 being applied to the substrate 122 (block 901) via, for example, a spin coating technique, and the substrate 122 being positioned on the chuck 110 of the base 108 of the fixture 104 (block 902). In some mounting configurations, the resin 124 is applied to the substrate 122 before the substrate 122 is positioned on the chuck 110. To form the nanopattern array, the mold 118 is moved and engaged with the resin 124 (block 906) to imprint the pattern 120 onto the resin 124. The resin 124 is cured using, for example, UV nanoimprint lithography (NIL) curing technique and / or thermal NIL curing technique (block 908).

[0073] To perform the demolding procedure, the mold 118 and the cured resin 124 are separated from each other (block 910). While the mold 118 and the resin 124 are separated, a separation force is determined that is applied as a function of the separation distance between the mold 118 and the resin 124 (block 912). In some implementations, a load cell 102 determines the force applied to the support 112, and system 100 determines the force applied as a function of the separation distance between the mold 118 and the resin 124. System 100 may also be used to determine the separation work value associated with the demolding procedure and the integral curve of the force with respect to the separation distance. Using the separation force and / or associated separation work, it is possible to identify which resin will produce a nanoimprint array with higher quality and / or a lower defect rate.

[0074] The process in Figure 10 begins with the application of resin 124 to a master template (block 1002), for example, via a spin coating technique. The resin 124 can then be filled into a pattern defined by the master template (similar to pattern 120).

[0075] The master template is positioned on the chuck 110 of the base 108 of the fixture 104 (block 1002). In some mounting configurations, the resin 124 is applied to the master template before it is positioned on the chuck 110. In such mounting configurations, while the resin 124 is being applied to the master template, a vacuum pump 138 can be used to pull the master template towards the chuck 110 to prevent the substrate 122 from moving. An anti-tack layer may be applied to the master template to reduce adhesion between the master template and the resin 124. The support 112 and base 108 of the fixture 104 are hinged together (block 1004), and the hinge point between the support 112 and the base 108 is changed between a first position and a second position (block 1006).

[0076] The unpatterned wheel is fixed within the mold support 116 (block 1008). In some implementations, fixing the unpatterned wheel within the mold support 116 involves connecting the mold 118 to a spring-biased clamp 202 to keep the unpatterned wheel under tension. The mold support 116 is connected to the support 112 of the fixture 104, for example, by nesting the mold support 116 within the support 112 (block 1010).

[0077] To form the mold 118, an unpatterned foil is moved and engaged with the resin 124 (block 1014) to bond the resin 124 to the foil and / or imprint the pattern 120 from the master template onto the resin 124. In some implementations, engaging the unpatterned foil and resin 124 on the master template involves rotating the mold support 116 toward the base 108 of the fixture 104. The resin 124 is cured using, for example, UV nanoimprint lithography (NIL) curing technology and / or thermal NIL curing technology (block 1016).

[0078] To perform the demolding procedure, the support 112 is connected to the load cell 102 (block 1018). The master template and the cured resin 124 are separated from each other (block 1020). Once the cured resin 124 separates from the master template, it remains attached to the unpatterned foil (now patterned with resin 124) to form the mold 118 for later use. While the master template and resin 124 are separated, a separation force is determined, applied as a function of the separation distance between the mold 118 and the resin 124 (block 1022). System 100 can also be used to determine the separation work value associated with the demolding procedure and the integral curve of the force with respect to the separation distance. Using the separation force and / or associated separation work, it is possible to identify which resin, release coating, and / or foil will produce a mold 118 with higher quality and / or a lower defect rate.

[0079] Figure 11 is a graph 1100 showing test results using an exemplary system 100 disclosed herein. In the tests performed, the demolding procedure was monitored to determine the force-to-displacement ratio for two different resins when producing nanopattern arrays with different pattern densities. Graph 1100 includes an X-axis 1102 representing the displacement of the load cell 102 and / or support 112 in millimeters (mm), and a Y-axis 1104 representing the force applied to the support 112 in Newtons (N). During the tests, the load cell 102 was moved at a speed of approximately 50 mm / min. However, the load cell 102 may be moved at different speeds, for example, 10 mm / min and / or 100 min / min.

[0080] In the graphs shown, the first curve 1106 represents the result using the first resin, and the second curve 1108 represents the result using the second resin. Curves 1106 and 1108 include drop regions 1110 having a sawtooth profile in which the force applied by system 100 decreases sharply. The sawtooth profile may be called a “stick-slip” and may result in the patterned portion of the nanopattern array transitioning to the unpatterned portion. Large changes in force in these drop regions 1110 can result in defects in the nanopattern array. As shown, the drop region 1110 in the second curve 1108 has a larger size, represented by the difference between reference numbers 1112 and 1114, and therefore, nanopattern arrays produced using the second resin may have more defects. The operator can use the feedback provided by graph 1100 to select the first resin with a lower separation force for a second rein with a higher separation force for larger-scale production. Several parameters that affect separation performance include the resin composition and the pattern of the nanopattern array.

[0081] Figure 12 is a graph 1200 showing test results using an exemplary system 100 disclosed herein. In the tests performed, the demolding procedure was monitored using different separation speeds to determine force versus displacement. Graph 1200 includes an X-axis 1202 representing the displacement of the load cell 102 and / or support 112 in millimeters (mm), and a Y-axis 1204 representing the force applied to the support 112 in Newtons (N).

[0082] In the graphs shown, the first curve 1206 represents the result using a separation rate of 10 mm / min, the second curve 1208 represents the result using a separation rate of 50 min / mm, and the third curve 1210 represents the result using a separation rate of 100 min / mm. As shown, the higher separation rates represented by the second curve 1208 and the third curve 1210 have higher separation forces and therefore can result in more defects present in the produced nanopattern array. More specifically, the separation forces of the second curve 1208 and the third curve 1210 are about 1 N higher than the separation force of the first curve 1206 at displacements of about 17 mm to about 30 mm or equivalent. Based on the feedback provided by Graph 1200, the operator can use a first separation rate (e.g., 100 mm / min) for the first part of the demolding process (e.g., displacement of approximately 15 mm or more) and a second separation rate (e.g., 10 mm / min) for the second part of the demolding process (e.g., displacement of 15 mm or more). More generally, the feedback provided by Graph 1200 enables the operator to create a custom separation rate profile with fewer product defects.

[0083] The foregoing description is provided to enable those skilled in the art to implement the various configurations described herein. While the subject art has been described in particular with reference to various figures and configurations, it should be understood that these are for illustrative purposes only and should not be construed as limiting the scope of the subject art.

[0084] When used herein, elements or processes described in the singular and followed by the word "a" or "an" should be understood not to exclude multiple such elements or processes unless such exclusion is explicitly stated. Furthermore, references to "one implementation" are not intended to be interpreted as excluding the existence of additional implementations that also incorporate the listed features. Moreover, unless explicitly stated otherwise, an implementation that "comprises," "includes," or "having" one or more elements having a particular characteristic may include additional elements, whether or not they possess that characteristic. Furthermore, the terms "comprising," "including," and "having" are used interchangeably herein.

[0085] The terms “substantially,” “approximately,” and “about” as used throughout this specification are used to describe and account for small variations resulting from processing variability, etc. For example, they may refer to ±5% or less, e.g., ±2% or less, e.g., ±1% or less, e.g., ±0.5% or less, e.g., ±0.2% or less, e.g., ±0.1% or less, e.g., ±0.05% or less.

[0086] Many other methods may exist for carrying out the subject art. Various functions and elements described herein may be divided in ways different from those shown without departing from the scope of the subject art. Various modifications to these implementations may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations. Thus, many changes and modifications can be made to the subject art by those skilled in the art without departing from the scope of the subject art. For example, a different number of a given module or unit may be used, different or more types of a given module or unit may be used, a given module or unit may be added, or a given module or unit may be omitted.

[0087] Underlined and / or italicized headings and subheadings are used solely for convenience and do not limit the subject art, nor are they referenced in connection with the interpretation of the description of the subject art. All structural and functional equivalents of elements of various implementations described throughout this disclosure, which are known to those skilled in the art or will become known thereafter, are expressly incorporated herein by reference and are intended to be included in the subject art. Furthermore, nothing disclosed herein is intended to be for publication only, whether such disclosure is expressly stated in the above description or not.

[0088] It should be understood that all combinations of the aforementioned concepts and further concepts, which are described in more detail below (on the premise that such concepts are not contradictory), are considered to be part of the subject matter disclosed herein. Specifically, all combinations of the claimed subject matter appearing at the end of this disclosure are considered to be part of the subject matter disclosed herein.

Claims

1. 1. A method comprising the following steps i) to ix) in order: i) applying a resin onto a substrate; ii) positioning the substrate on a chuck in the base of a fixture; iii) hingedly connecting the support and the base of the fixture; iv) varying a hinge point between the support and the base between a first position and a second position; v) securing the mold in a mold support and connecting the mold support to a support of the fixture; vi) moving the mold to engage the resin; vii) curing the resin; viii) separating the mold and the resin; and ix) deriving the separation force applied during separation of the mold and the resin as a function of separation distance between the mold and the resin.

2. The method of claim 1 , wherein altering the hinge point comprises moving the hinge point away from a plane defined by the mold or the mold support.

3. 3. The method of claim 1 or 2, further comprising connecting the support to a load cell, and wherein separating the mold and the resin comprises separating the mold and the resin while the support is connected to the load cell.

4. The method of claim 3 , wherein coupling the support and the load cell comprises clamping a strap at an end of the support and coupling the strap to the load cell.

5. The method of claim 4, wherein clamping the strap includes closing a clamp at an end of the support.

6. The method of claim 4 or 5, wherein the strap comprises a zip tie.

7. The method of any one of claims 1 to 6, wherein engaging the mold and the resin comprises rotating the mold support toward the base of the fixture.

8. The method of any one of claims 1 to 7, further comprising using a vacuum to pull the substrate towards the chuck.

9. 1. An apparatus comprising: a fixture including: 1) a base having a chuck; and 2) a support hingedly connected to the base and including a mold support receptacle; the support includes a support bracket, and the base includes a base bracket hingedly connected to the support bracket; each of the support bracket and the base bracket includes an L-shaped bracket; a hinge point between the support bracket and the base bracket is spaced from a plane defined by the support; the base bracket includes a plurality of connecting holes that allow a hinge point between the support and the base to vary between a first position and a second position; The apparatus wherein the support is connectable to a load cell.

10. 10. The apparatus of claim 9, wherein the support is rectangular and includes a corner support at each corner of the support.

11. The apparatus of claim 9 or 10, wherein the base includes a port fluidly connected to the chuck.

12. An apparatus according to any one of claims 9 to 11, wherein the end of the support comprises a clamp connectable to the load cell via a strap.

13. 1. An apparatus comprising: a system, the system comprising: A load cell; The apparatus of any one of claims 9 to 12, further comprising a mold support received within the mold support receptacle.

14. The apparatus of claim 13, further comprising an unpatterned foil coupled within the mold support, a master template positioned on the chuck, and a resin disposed on the master template.

15. 14. The apparatus of claim 12 or 13, further comprising a mold coupled within the mold support, a substrate positioned on the chuck, and a resin disposed on the substrate.

16. The apparatus described in claim 15, wherein the mold is movable to engage with the resin and is hardenable, and the load cell is connected to the support to measure the separation force when the mold and the resin separate.

17. The apparatus described in claim 16, wherein the load cell measures the force applied to the support, and the system derives the force applied to the support as a function of the separation distance between the mold and the resin.

18. The apparatus of any one of claims 13 to 17, further comprising a set screw connecting the mold support within the mold support receptacle.

19. The apparatus of any one of claims 13 to 18, wherein the chuck is a vacuum chuck.

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