Method for manufacturing nanoimprint template and nanoimprint method
By forming a hard layer on the surface of a flexible template, the nanoimprint template solves the problems of easy damage and insufficient mechanical strength of traditional templates, realizing a low-cost, high-durability nanoimprint template suitable for high-end device manufacturing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU NDNANO MICRO & NANO CO LTD
- Filing Date
- 2026-04-29
- Publication Date
- 2026-06-23
Smart Images
Figure CN122260722A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nanoimprint technology, specifically relating to a method for preparing a nanoimprint template and a nanoimprint method. Background Technology
[0002] Traditional rigid nanoimprint stencils are expensive and prone to chipping, cracking, and structural wear, resulting in a limited lifespan. Conventional flexible adhesive-based stencils suffer from insufficient mechanical strength and durability, and are susceptible to structural deformation and aging during continuous imprinting.
[0003] Therefore, to address the aforementioned technical problems, it is necessary to provide a method for preparing a nanoimprint template and a nanoimprinting method. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing a nanoimprint template and a nanoimprinting method. The process is simple and low-cost, and can obtain a flexible nanoimprint template with excellent fatigue resistance and surface strengthening.
[0005] To achieve the above objectives, a specific embodiment of the present invention provides a method for preparing a nanoimprint template. The method includes: providing a first template having a nanoimprint pattern; filling the surface of the nanoimprint pattern of the first template with a liquid prepolymer colloid; curing the liquid prepolymer colloid to form a second template, the second template being a flexible template; peeling the second template off from the first template; and subjecting the second template to ultraviolet light irradiation treatment to cause a crosslinking reaction on the surface of the second template to form a hard layer, thereby obtaining the nanoimprint template.
[0006] In one or more embodiments of the present invention, the preparation method further includes: mixing polydimethylsiloxane prepolymer and curing agent at a preset weight ratio, stirring evenly and then degassing to obtain liquid prepolymer colloid.
[0007] In one or more embodiments of the present invention, the second template is subjected to ultraviolet irradiation treatment, including: providing an ultraviolet light source with a wavelength of 172~365nm, controlling the distance between the second template and the ultraviolet light source to be 10~20cm, and irradiating the surface of the second template with the ultraviolet light source.
[0008] In one or more embodiments of the present invention, the irradiation duration is 20-80 minutes. The irradiance of the ultraviolet irradiation treatment is 320-340 mW / cm². 2 .
[0009] In one or more embodiments of the present invention, the first template is a rigid template.
[0010] In one or more embodiments of the present invention, the thickness of the second template is less than or equal to 1 cm.
[0011] In one or more embodiments of the present invention, curing the liquid prepolymer colloid to form a second template includes: thermally curing the liquid prepolymer colloid at a first temperature.
[0012] In one or more embodiments of the present invention, the first temperature range is greater than or equal to 80°C. The thermosetting duration is 30 minutes to 3 hours, wherein the first temperature is greater than room temperature.
[0013] In one or more embodiments of the present invention, the second template is subjected to ultraviolet irradiation treatment and then thermally cured to cause the hard layer to undergo a cross-linking reaction, wherein the thermal curing duration is 20-60 min and the thermal curing temperature is 80-200℃.
[0014] A second aspect of this disclosure provides a nanoimprinting method, comprising: providing a substrate and forming an imprinting adhesive layer on the surface of the substrate; providing a nanoimprinting template, aligning the nanoimprinting template with the imprinting adhesive layer, applying pressure and performing nanoimprinting, wherein the nanoimprinting template is obtained based on the preparation method according to any one of claims 1 to 8; curing the imprinting adhesive layer by ultraviolet light irradiation while maintaining pressure; releasing the pressure and peeling the nanoimprinting template off the substrate.
[0015] In one or more embodiments of the present invention, the nanoimprinting method further includes: cleaning the surface of the nanoimprinting template after peeling it off from the substrate.
[0016] Compared with existing technologies, the preparation method and nanoimprinting method of the present invention use a replicated adhesive template to replace expensive templates such as silicon and quartz for imprinting, significantly reducing the template preparation cost. By subjecting the flexible second template to specific ultraviolet light strengthening treatment, a deeper cross-linked network can be formed on its surface, effectively improving the surface mechanical strength, hardness, and wear resistance. This allows the nanoimprint template to withstand the pressure and solvent erosion during multiple imprinting cycles, maintaining the integrity of the pattern structure and significantly extending its service life. Simultaneously, this ultraviolet treatment only acts on the surface layer of the second template, maintaining good overall flexibility, adapting to minor undulations on the substrate surface, reducing imprinting defects, and improving yield. Furthermore, the ultraviolet strengthening process is simple, requires no complex equipment, and is easily integrated into existing adhesive template preparation processes, making it suitable for large-scale production. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a flowchart of a method for preparing a nanoimprint template in one embodiment of the present invention;
[0019] Figure 2 This is a structural diagram of the second template in one embodiment of the present invention;
[0020] Figure 3 This is a structural diagram of a nanoimprint template in one embodiment of the present invention;
[0021] Figure 4 This is a flowchart of a nanoimprinting method in one embodiment of the present invention. Detailed Implementation
[0022] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.
[0023] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.
[0024] It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. In the embodiments shown in this disclosure, directional representations such as up, down, left, right, front, and back are relative and are used to explain the relative structure and movement of different components in this disclosure. These representations are appropriate when the components are in the positions shown in the figures. However, if the description of the component positions changes, then these representations are considered to change accordingly.
[0025] As mentioned in the background section, in the field of micro-nano fabrication, nanoimprint technology has become a key process for fabricating micro-nano structures due to its advantages such as high resolution, low cost, and high efficiency. Traditional rigid nanoimprint templates mostly use silicon, quartz, or hard metal substrates. Although they offer high structural precision, they suffer from high material costs, complex processing techniques, and long production cycles. At the same time, rigid templates are brittle and prone to chipping, cracking, and structural wear during imprinting, demolding, and reuse, resulting in a limited lifespan and significantly increasing the overall cost of large-scale production.
[0026] To compensate for the shortcomings of rigid templates, existing technologies use flexible adhesive templates, which have advantages such as good flexibility, excellent adhesion, and ease of imprinting on curved surfaces and large areas. However, conventional flexible adhesive materials generally suffer from defects such as insufficient mechanical strength, poor wear resistance, and poor dimensional stability. During continuous imprinting, they are prone to structural deformation, adhesive damage, and aging failure, resulting in deterioration of imprinted pattern accuracy, increased defects, and insufficient durability to meet the needs of industrial mass production.
[0027] Therefore, existing nanoimprint templates cannot simultaneously achieve high precision, high mechanical strength, long service life, and low cost, which restricts the large-scale application of nanoimprint technology in the field of high-end device manufacturing. There is an urgent need to develop a nanoimprint template that combines excellent structural stability, mechanical durability, and economy.
[0028] Based on the above understanding, the technical approach of this disclosure is to combine the characteristics of flexible templates and rigid templates to construct a "hard on the outside and soft on the inside" nanoimprint template, thereby obtaining high surface durability and overall flexibility, while solving the problem that traditional adhesive-based templates become weak when they are flexible.
[0029] Please refer to Figure 1 As shown, one embodiment provides a method for preparing a nanoimprint template, specifically including steps S101 to S104.
[0030] S101 provides a first template with a nanoimprint pattern.
[0031] Specifically, the first template is a rigid template, such as a silicon template or a quartz template. The first template includes a first surface and a second surface arranged opposite to each other, and the first surface is provided with a nanoimprint pattern.
[0032] S102, the liquid prepolymer colloid is filled onto the surface of the nanoimprint pattern of the first template, the liquid prepolymer colloid is cured and a second template 10 is formed, wherein the second template 10 is a flexible template.
[0033] Specifically, the second template 10 is solid and has good overall flexibility and elasticity, and can undergo slight bending, bonding and other deformations under certain external forces.
[0034] In step S102, the polydimethylsiloxane (PDMS) prepolymer and the curing agent are mixed at a preset weight ratio, stirred evenly, and then degassed to obtain a liquid prepolymer colloid. For example, the weight ratio between the polydimethylsiloxane (PDMS) prepolymer and the curing agent can be 10:1, and the curing agent includes hydrogen-containing silicone oil, tetraethyl orthosilicate, or oxime silanes, etc.
[0035] The purpose of degassing is to remove air bubbles to avoid affecting the molding of the second template. The degassed liquid prepolymer colloid is uniformly coated on the surface of the nanoimprint pattern of the first template and left to stand for a preset time to allow the liquid prepolymer colloid to fully contact the nanoimprint pattern, ensuring that the second template 10 can completely transfer the corresponding nanoimprint pattern.
[0036] In step S102, the liquid prepolymer colloid is thermally cured at high temperature to form the second template 10. The thermal curing environment is an oven or heating chamber, wherein the temperature inside the oven or heating chamber is greater than or equal to 80°C, preferably 80~100°C, and the thermal curing duration is 30 minutes to 3 hours.
[0037] Under thermosetting conditions, the active end groups in the liquid prepolymer colloid undergo hydrosilylation crosslinking with the crosslinking sites in the curing agent. The linear polydimethylsiloxane molecular chains are connected to each other through covalent bonds to form a three-dimensional network crosslinked structure. The system gradually changes from a flowable liquid to an insoluble and infusible elastic solid, thereby obtaining a second template 10 with good flexibility, elasticity and structural stability.
[0038] S103, the second template 10 is peeled off from the first template.
[0039] Please refer to Figure 2 As shown, the second template 10 is a flexible template, and the nanoimprint pattern on the second template 10 is complementary to the nanoimprint pattern on the first template.
[0040] S104, by subjecting the second template 10 to ultraviolet irradiation treatment, a hard layer is formed on the surface of the second template 10 to obtain a nanoimprint template.
[0041] Step S104 specifically includes: providing an ultraviolet light source with a wavelength of 172~365nm, controlling the distance between the second template 10 and the ultraviolet light source to be 10~20cm, and irradiating the surface of the second template 10 with the ultraviolet light source for a duration of 20~80min, and the irradiance of the ultraviolet light irradiation treatment is 320~340mW / cm2.
[0042] Please combine Figure 3As shown, ultraviolet irradiation treatment causes further cross-linking of the surface molecular chains of the cured second template 10, forming a hard layer 11 with a cross-linking density higher than that of the internal bulk phase, while the interior of the second template 10 retains its flexible properties. That is, the nanoimprint template of this disclosure includes a hard layer 11 and a flexible structural layer 12, with the strength of the hard layer 11 being greater than that of the flexible structural layer 12, exhibiting an overall gradient property of hard on the outside and flexible on the inside.
[0043] Specifically, the thermocured PDMS (i.e., the second template 10) forms an intermolecular cross-linking network, but does not destroy the original Si-C, CH, and Si-O bonds. The photon energy of high-energy ultraviolet light is higher than the bond energies of Si-C, CH, and Si-O bonds, thus directly severing some Si-C or CH bonds, generating carbon-centered free radicals with unpaired electrons. These carbon free radicals react with reactive oxygen species, ultimately removing carbon in the form of CO2, etc. The remaining silicon and oxygen atoms recombine to form a denser, rigid inorganic silicon oxide hardened layer (chemical composition close to SiO2). Therefore, macroscopically, a hard layer 11 forms on the surface of the second template. Due to the limited penetration depth of ultraviolet light and the limited diffusion range of reactive oxygen species, this reaction only occurs at depths of tens of nanometers to micrometers below the surface; therefore, the interior of the second template 10 remains elastic.
[0044] It should be noted that the above content is only an explanation of the principle and does not limit the complete cross-linking reaction of the hard layer 11. The degree of cross-linking of the hard layer 11 is controllable, and the degree of cross-linking of the hard layer 11 can be controlled by changing the exposure dose.
[0045] Furthermore, if the surface strength of the second template 10 does not reach the preset strength range after ultraviolet irradiation treatment, the second template 10 is subjected to a second thermal curing to cause the hard layer 11 to undergo a cross-linking reaction again, thereby increasing the hardness of the hard layer and improving the surface strength of the target nanoimprint template. The thermal curing duration is 20-60 minutes, and the thermal curing temperature is 80-200℃.
[0046] The nanoimprint template disclosed herein possesses high durability and long lifespan. By subjecting the flexible second template 10 to ultraviolet light strengthening treatment under specific conditions, a deeper cross-linked network is induced on its surface, effectively improving the mechanical strength, hardness, and wear resistance of the nanoimprint template surface. This enables the nanoimprint template to resist pressure and solvent erosion during multiple imprinting cycles, maintaining pattern integrity and significantly extending its service life.
[0047] The nanoimprint template disclosed herein also maintains its flexibility advantage: ultraviolet irradiation treatment mainly enhances the surface layer of the second template 10, while its interior remains flexible. Therefore, the nanoimprint template as a whole maintains good flexibility, can adapt to the slight undulations on the substrate surface, reduce imprinting defects, and improve yield.
[0048] Furthermore, the overall thickness of the second template 10 is less than or equal to 1 cm, and the thickness of the rigid layer 11 is much smaller than the overall thickness of the second template 10.
[0049] Please refer to Figure 4 As shown, this disclosure also provides a nanoimprinting method, specifically including steps S201 to S204.
[0050] S201 provides a substrate and forms an imprint adhesive layer on the substrate surface.
[0051] For example, the substrate can be a rigid substrate such as silicon wafer, quartz, or glass. An imprinting adhesive is spin-coated onto the substrate surface to form an imprinting adhesive layer. The thickness of the imprinting adhesive layer ranges from 200 to 400 nm; preferably, the thickness is 300 nm. The material of the imprinting adhesive layer 20 is preferably a gelatin-based imprinting adhesive or an acrylic resin.
[0052] S202, providing a nanoimprint template, aligning the nanoimprint template with the imprinting adhesive layer, applying pressure and performing nanoimprinting, wherein the nanoimprint template is obtained based on the above preparation method.
[0053] Nanoimprinting is performed using a nanoimprint template under a certain pressure, allowing the imprinting adhesive layer to fully fill the nanoimprint pattern within the template, thus maintaining the integrity of the microstructure transfer of the nanoimprint pattern. The certain pressure range is 1~2 bar, preferably 1 bar.
[0054] S203, the imprinted adhesive layer is cured by ultraviolet light irradiation while maintaining pressure.
[0055] The imprinted adhesive layer is irradiated with ultraviolet light at a wavelength of 365 nm. The ultraviolet light passes through the nanoimprint template and cures the imprinted adhesive layer. The curing time is 60-80 seconds. It is understandable that the curing time of the imprinted adhesive layer is usually very short, and it will not cause further cross-linking reaction of the nanoimprint template.
[0056] S204 releases the pressure and peels the nanoimprint template off the substrate.
[0057] Furthermore, the nanoimprinting method also includes: after peeling the nanoimprint template from the substrate, cleaning the residual adhesive residue on the surface of the nanoimprint template with a solvent (such as isopropanol), and the nanoimprint template can be used for the next imprinting after drying.
[0058] The nanoimprint template provided in this disclosure has a hard layer, thus achieving a resolution and regularity comparable to that of a hard template in nanostructure replication. At the same time, thanks to the flexible structural layer retained inside, it has excellent adhesion, crack resistance and easy demolding, which can effectively reduce imprinting defects and improve pattern integrity, and has greater advantages in processing yield and applicable substrate range.
[0059] The present disclosure will be further described below with reference to specific embodiments.
[0060] Example 1:
[0061] A silicon template with a nanowire array structure was provided. PDMS prepolymer and curing agent were mixed at a weight ratio of 10:1, stirred until homogeneous, and degassed. The mixture of PDMS prepolymer and curing agent was poured onto the surface of the silicon template and heat-cured in an oven at 80°C for 2 hours. After curing, the cured PDMS prepolymer was peeled off from the silicon template to obtain a flexible second template. The second template was then irradiated for 30 minutes at a distance of approximately 10 cm from a 365 nm ultraviolet lamp, with both its upper and lower surfaces subjected to continuous irradiation. After irradiation, a surface-strengthened nanoimprint template was obtained.
[0062] Example 2:
[0063] A silicon template with a nanopillar array structure was provided. PDMS prepolymer and curing agent were mixed at a weight ratio of 10:1, stirred until homogeneous, and degassed. The mixture of PDMS prepolymer and curing agent was poured onto the surface of the silicon template and heat-cured in an oven at 200°C for 30 minutes. After curing, the cured PDMS prepolymer was peeled off from the silicon template to obtain a flexible second template. The second template was irradiated continuously for 40 minutes at an irradiance of 340 mW / cm². 2 After irradiation, a surface-strengthened nanoimprint template is obtained.
[0064] Example 3:
[0065] A layer of UV-curable imprinting adhesive was spin-coated onto a clean silicon wafer substrate. The nanoimprinted pattern surface of the nanoimprint template prepared in Example 1 or Example 2 was brought into contact with the imprinting adhesive on the silicon wafer substrate. A pressure of 2 bar was applied using a nanoimprinting device to allow the imprinting adhesive to fully fill the nanostructure of the nanoimprint. While maintaining the pressure, the imprinting adhesive was irradiated with ultraviolet light (wavelength 365 nm) for 60 seconds to cure it.
[0066] Release the pressure and gently peel the surface-reinforced nanoimprint template from the substrate. At this point, the cured structure of the imprinting adhesive replicates the nanoimprint pattern of the surface-reinforced nanoimprint template. Clean any remaining adhesive residue on the nanoimprint template surface with isopropyl alcohol; after drying, it is ready for the next imprinting.
[0067] As can be seen from the above technical solutions, this disclosure has the following beneficial effects:
[0068] Using a replicated adhesive template instead of expensive templates such as silicon and quartz for imprinting significantly reduces template preparation costs. By subjecting the flexible template to specific UV-enhanced treatment, a deeper cross-linked network can be formed on its surface, effectively improving surface mechanical strength, hardness, and wear resistance. This allows the nanoimprint template to withstand pressure and solvent erosion during multiple imprinting cycles, maintaining the integrity of the pattern structure and significantly extending its service life. Simultaneously, this UV treatment only affects the template surface, maintaining overall good flexibility, adapting to minor surface undulations on the substrate, reducing imprinting defects, and improving yield. Furthermore, the UV-enhanced process is simple, requires no complex equipment, and is easily integrated into existing adhesive template preparation processes, making it suitable for large-scale production.
[0069] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for preparing a nanoimprint template, characterized in that, The preparation method includes: Provide a first template with a nanoimprint pattern; A liquid prepolymer colloid is filled onto the surface of the nanoimprint pattern of the first template, and the liquid prepolymer colloid is cured to form a second template, wherein the second template is a flexible template; Peel the second template off the first template; By subjecting the second template to ultraviolet irradiation, a cross-linking reaction occurs on the surface of the second template, forming a hard layer, thus obtaining a nanoimprint template.
2. The method for preparing a nanoimprint template according to claim 1, characterized in that, The preparation method further includes: mixing polydimethylsiloxane prepolymer and curing agent at a preset weight ratio, stirring evenly and then degassing to obtain liquid prepolymer colloid.
3. The method for preparing a nanoimprint template according to claim 1, characterized in that, The second template is subjected to ultraviolet irradiation treatment, including: providing an ultraviolet light source with a wavelength of 172~365nm, controlling the distance between the second template and the ultraviolet light source to be 10~20cm, and irradiating the surface of the second template with the ultraviolet light source.
4. The method for preparing a nanoimprint template according to claim 3, characterized in that, The irradiation duration is 20–80 min; and / or, The irradiance for ultraviolet irradiation treatment is 320~340mW / cm². 2 .
5. The method for preparing a nanoimprint template according to claim 1, characterized in that, The first template is a rigid template; and / or, the thickness of the second template is less than or equal to 1 cm.
6. The method for preparing a nanoimprint template according to claim 1, characterized in that, Curing the liquid prepolymer colloid to form a second template includes: thermally curing the liquid prepolymer colloid at a first temperature, wherein the first temperature is greater than room temperature.
7. The method for preparing a nanoimprint template according to claim 6, characterized in that, The first temperature range is greater than or equal to 80°C; and / or, The heat curing time is 30 minutes to 3 hours.
8. The method for preparing a nanoimprint template according to claim 1, characterized in that, After the second template is subjected to ultraviolet irradiation, it is then thermo-cured to cause the hard layer to undergo a cross-linking reaction. The thermo-curing duration is 20-60 minutes and the thermo-curing temperature is 80-200°C.
9. A nanoimprinting method, characterized in that, include: A substrate is provided, and an imprinting adhesive layer is formed on the surface of the substrate; A nanoimprint template is provided, the nanoimprint template is aligned with the imprint adhesive layer, pressure is applied and nanoimprinting is performed, wherein the nanoimprint template is obtained based on the preparation method of any one of claims 1 to 8; The imprinted adhesive layer is cured by ultraviolet light irradiation while maintaining pressure. Release the pressure and peel the nanoimprint template off the substrate.
10. The nanoimprinting method according to claim 9, characterized in that, The nanoimprinting method further includes: after peeling the nanoimprint template from the substrate, cleaning the surface of the nanoimprint template.