UV-Nanoimprint-based selective deposition process for improving metal transfer rate on polymeric patterns

Abstract

The present invention relates to a UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, wherein a chemical bond is formed between a UV-curing resin and a metal thin film using metal halogenation to efficiently perform selective deposition of a metal on a polymer structure. The method comprises the steps of: manufacturing an intaglio mold for fabricating a plasmonic device having a positive pattern; depositing a metal thin film on the mold; applying a chemical reaction control material on the metal thin film; supplying light energy greater than the atomic bond-dissociation energy to the chemical reaction control material through a UV exposure process; removing the metal thin film; and performing a UV-curing imprint for the formation of a polymer nano pattern and the selective deposition of a metal.

Description

Technology Field

[0001] The present invention relates to a plasmonic device manufacturing process, and more specifically, to a UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, which enables efficient selective deposition of a metal on a polymer structure by forming a chemical bond between a UV-curing resin and a metal thin film using metal halogenation. Background Technology

[0002] Recently, devices capable of inducing plasmonic effects that control or amplify incident light through various patterns using nano / micro structures are being developed.

[0003] The plasmonic effect is a phenomenon that occurs when free electrons in a metal collectively vibrate upon the incidence of light on a metal and dielectric surface; to induce this phenomenon, the metal must be deposited to a certain height on the micro / nano pattern.

[0004] In conventional technology, to fabricate such plasmonic patterns, a metal is deposited entirely on a dielectric structure of a specific structure and then etched using an e-beam lithography method to leave the metal only on the specific structure, or a specific dielectric structure is fabricated and then metal nanoparticles are deposited using a dipping or spread method to create nanogaps between the metal nanoparticles, thereby fabricating a plasmonic surface that amplifies a specific signal using an enhanced electric field between the nanogaps.

[0005] However, conventional process methods have very slow production speeds, making them unsuitable for large-area production, or there were difficulties in achieving selective metal deposition.

[0006] UV-cured nanoimprints are used in various fields because they produce micro / nano patterns using UV-curing resins that cure under UV light, allowing for fast production speeds and simple processes; however, there have been difficulties in transferring only the metal of specific surfaces due to the characteristics of the UV-curing resins.

[0007] To complement this, a technology has been studied that enables the transfer of more than 70% of the metal on a specific surface by applying heat and pressure using thermal nanoimprinting.

[0008] However, in fields utilizing light, processes with higher yields were required to maintain precision, and thermal nanoimprinting had the disadvantage of being difficult to mass-produce.

[0009] While it is possible to fabricate sophisticated polymer patterns at the nanoscale in this way, it is impossible to form metal thin film patterns; and although it is possible to deposit metal thin films on polymer patterns by combining them with techniques such as sputtering, there are still limitations in achieving selective deposition.

[0010] Organic materials, including UV-curing resins, are non-polar due to the presence of hydrocarbon groups, and metal materials used in plasmonic devices primarily utilize unreactive precious metals to induce plasmonic effects at specific wavelengths; consequently, they exhibit very poor adhesion to one another, which is a major cause of reduced metal transfer yield in conventional processes.

[0011] Chloroform is a liquid molecule composed of three chlorine atoms, one carbon atom, and one hydrogen atom, and has strong polarity.

[0012] Chloroform treatment on a polymer substrate could significantly improve mutual adhesion by mediating artificial chemical bonding between the polymer containing oxygen atoms and the precious metal. This allowed for a simpler and faster achievement of stronger adhesion compared to conventional adhesion enhancement methods such as oxygen plasma treatment and metal intermediate layers.

[0013] These improvements were achieved by spin coating or vaporizing chloroform onto a polymer and then depositing a metal on it by sputtering or evaporation.

[0014] However, chloroform reacts directly with the polymer substrate, causing deformation of the polymer and potentially leading to structural deformation and degradation of optical properties.

[0015] Therefore, in order to apply chloroform treatment to plasmonic devices with nano-scale pattern sizes, there is a need to develop new technology that appropriately induces chemical reactions to minimize degradation of optical device characteristics and can be applied to UV curing processes to enable large-area production. Prior art literature

[0016] Republic of Korea Registered Patent No. 10-2212483 Republic of Korea Published Patent No. 10-2021-0085550 Republic of Korea Registered Patent No. 10-1542942 The problem to be solved

[0017] The present invention aims to solve the problems of the conventional plasmonic device manufacturing process by providing a UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, which enables efficient selective deposition of a metal on a polymer structure by forming a chemical bond between a UV-curing resin and a metal thin film (Ag) using metal halogenation.

[0018] The present invention aims to provide a UV-cured nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, which enables selective deposition of a metal thin film (Ag) on ​​a polymer pattern while suppressing deformation of the structure and degradation of optical properties, thereby making it advantageous for large-area production.

[0019] The present invention aims to provide a UV-cured nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, which enables the efficient fabrication of plasmonic devices by applying a method of forming bonds between a metal (Ag) and a chlorine atom using a UV-cured nanoimprint and supplying light energy to form bonds between a UV-cured resin and a metal.

[0020] Other objectives of the present invention are not limited to those mentioned above, and other unmentioned objectives will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0021] A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern according to the present invention for achieving the above-mentioned purpose comprises: a step of manufacturing an intaglio mold for fabricating a plasmonic device having a positive pattern; a step of depositing a metal thin film on the mold; a step of applying a chemical reaction control material on the metal thin film; a step of supplying light energy greater than the atomic bond-dissociation energy to the chemical reaction control material through a UV exposure process; a step of removing the metal thin film; and a step of performing a UV-curing imprint for the formation of a polymer nano pattern and the selective deposition of a metal.

[0022] Here, the step of depositing a metal thin film is characterized by using a physical deposition process including sputtering or evaporation.

[0023] And the chemical reaction control material is characterized by being used to form a metal-chlorine chemical bond by inducing a halogenation reaction between chlorine atoms on a metal thin film and the metal.

[0024] And the chemical reaction control substance is characterized by the use of chloroform.

[0025] In addition, it is characterized by inducing the dissociation of chlorine atoms in chloroform and a halogenation reaction of the metal, thereby causing the separation of chlorine atoms and a spontaneous reaction between the metal and chlorine atoms to form a bond.

[0026] And in the step of supplying light energy greater than the bond-dissociation energy of atoms to a chemical reaction control material through a UV exposure process, the UV exposure process is characterized by irradiating UV light of 385 nm or less onto a metal thin film coated with a chemical reaction control material.

[0027] And in the step of removing the metal thin film, the method is characterized by using an adhesive tape peeling process to remove the unnecessary upper metal thin film, excluding the metal within the nanostructure on the intaglio mold.

[0028] Furthermore, in the step of supplying light energy exceeding the bond-dissociation energy of atoms to the chemical reaction control material via a UV exposure process, chlorine atoms are separated from the molecules of the chemical reaction control material, and the separated chlorine atoms meet the metal of the metal thin film to spontaneously form a metal chloride. Additionally, additional light energy is supplied during the UV curing imprint process to facilitate the formation of chemical bonds between the metal chloride and oxygen atoms on the polymer, thereby allowing the chemical bond between the metal halide and the polymer to be stronger than the bond strength between the mold and the metal, so that the metal within the intaglio mold is selectively deposited onto a specific nano-pattern of the polymer.

[0029] In addition, it is characterized by fabricating the intaglio mold with Si and using Ag for the metal thin film. Effects of the invention

[0030] The UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern according to the present invention, as described above, has the following effects.

[0031] First, by utilizing metal halogenation to form a chemical bond between the UV-curing resin and the metal thin film, the selective deposition of metal on the polymer structure can be efficiently performed.

[0032] Second, by using a UV-curing nanoimprint-based fabrication method, selective deposition of a metal thin film on a polymer pattern is performed to suppress deformation of the structure and degradation of optical properties, making it advantageous for large-area production.

[0033] Third, by applying a method that forms bonds between metal and chlorine atoms using UV-curing nanoimprints and supplies light energy to form bonds between the UV-curing resin and the metal, it is possible to manufacture efficient plasmonic devices. Brief explanation of the drawing

[0034] FIG. 1 is a schematic diagram showing the mechanism of a chemical reaction occurring during the fabrication process for fabricating a plasmonic device according to the present invention. FIG. 2 is a process flowchart illustrating a UV-curing nanoimprint-based selective deposition process method according to the present invention. FIGS. 3a to 3f are schematic diagrams of a UV-cured nanoimprint-based selective deposition process for improving the metal transfer rate on a polymer pattern according to the present invention. Figure 4 is a schematic diagram showing the effects of chloroform treatment and photodissociation reaction on the metal transfer rate. Figure 5 is a graph of the optical amplification characteristics of a plasmonic device fabricated according to the present invention. Specific details for implementing the invention

[0035] Hereinafter, a preferred embodiment of a UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern according to the present invention will be described in detail as follows.

[0036] The features and advantages of the UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern according to the present invention will become apparent from the detailed description of each embodiment below.

[0037] Figure 1 is a schematic diagram showing the mechanism of a chemical reaction occurring during the fabrication process for fabricating a plasmonic device according to the present invention.

[0038] The terms used in this disclosure have been selected to be as widely used and general as possible, taking into account their functions within this disclosure; however, these terms may vary depending on the intent of those skilled in the art, case law, the emergence of new technologies, etc. Additionally, in specific cases, terms have been selected at the applicant's discretion, and in such cases, their meanings will be described in detail in the relevant description of the invention. Therefore, terms used in this disclosure should be defined not merely by their names, but based on their meanings and the overall content of this disclosure.

[0039] When a part of a specification is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0040] The UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern according to the present invention enables efficient selective deposition of a metal on a polymer structure by forming a chemical bond between a UV-curing resin and a metal thin film using the halogenation of the metal.

[0041] To this end, the present invention provides a UV-curing nanoimprint-based plasmonic device fabrication process method for efficiently and rapidly fabricating devices.

[0042] During the process of the present invention, by forming a chemical bond between the polymer and the metal through chloroform treatment, it is possible to improve the transfer rate of the metal thin film onto the polymer phase and provide additional stability to the fabricated device.

[0043] The process for fabricating a plasmonic device according to the present invention comprises: manufacturing an intaglio mold for fabricating a plasmonic device having a raised pattern; physical vapor deposition on the mold for depositing a metal thin film; applying chloroform onto the metal thin film; UV exposure for the dissociation of chlorine atoms in chloroform and the formation of metal chloride; peeling off an adhesive tape to remove an unnecessary upper metal thin film excluding the metal within the nanostructure on the intaglio mold; and forming a polymer nanopattern and a selective deposition process of metal.

[0044] In the present invention, energy is supplied in a non-spontaneous reaction and a spontaneous reaction occurs through UV exposure. Although chemical bonding between a metal and a chlorine atom does not occur spontaneously by the simple application of chloroform molecules, when light energy corresponding to or greater than the bond-dissociation energy of a chlorine atom in a chloroform molecule is supplied, the chlorine atom separates, and a spontaneous reaction occurs between the metal and the chlorine atom to form a bond.

[0045] Subsequently, a small amount of additional light energy is supplied during the UV curing imprint process to form a bond between the polymer and the metal chloride, and an artificial chemical bond is formed between the polymer and the metal.

[0046] In addition, the deposition of the metal thin film utilizes a physical vapor deposition process that has strong linearity and poor adhesion to the substrate, thereby minimizing the deposition of the metal thin film on the sides of the mold and improving the fidelity of the finished flexible device.

[0047] In addition, UV light with a wavelength of ~385 nm and a power level above a certain threshold is used for the decomposition of chlorine atoms in chloroform, and for UV exposure to form bonds with the polymer, an appropriate power is applied to prevent the dissociation of metal and chlorine atoms, thereby controlling the wavelength and power according to the situation to avoid causing unintended additional reactions.

[0048] Figure 1 shows the mechanism of a chemical reaction occurring during the fabrication process for a plasmonic device, sequentially illustrating that chlorine atoms are separated from chloroform molecules due to exposure to light with a wavelength of 385 nm or less, spontaneously form metal chloride when the separated chlorine atoms come into contact with a metal, and that chemical bonds are formed between the metal chloride and oxygen atoms in the polymer due to the supply of additional light energy.

[0049] FIG. 2 is a process flowchart illustrating a UV-cured nanoimprint-based selective deposition process method according to the present invention.

[0050] A UV-curing nanoimprint-based selective deposition process for improving the metal transfer rate on a polymer pattern according to the present invention comprises, broadly: a step of manufacturing an intaglio mold for fabricating a plasmonic device having a positive pattern (S201); a step of performing physical vapor deposition on the mold for depositing a metal thin film (S202); a step of applying chloroform on the metal thin film (S203); a UV exposure step for dissociating chlorine atoms in chloroform and forming a metal chloride (S204); a step of peeling off an adhesive tape (S205) for removing an unnecessary upper metal thin film excluding the metal within the nanostructure on the intaglio mold; and a UV-curing imprint step (S206) for achieving the formation of a polymer nano pattern and the selective deposition of a metal.

[0051] Here, it is preferable to fabricate the intaglio mold with Si and use Ag for the metal thin film, but is not limited thereto.

[0052] Then, in the exposure process during the UV exposure step (S204), chlorine atoms are separated from chloroform molecules, which are chemical reaction control substances. The separated chlorine atoms meet with the metal of the metal thin film to spontaneously form a metal chloride. Additional light energy is supplied during the UV curing imprint process to facilitate the formation of chemical bonds between the metal chloride and oxygen atoms on the polymer. This results in a chemical bond between the metal halide and the polymer being stronger than the bond between the mold and the metal, thereby allowing the metal within the intaglio mold to be selectively deposited onto a specific nano-pattern of the polymer.

[0053] FIGS. 3a to 3f are schematic diagrams of a UV-cured nanoimprint-based selective deposition process for improving the metal transfer rate on a polymer pattern according to the present invention.

[0054] First, as shown in FIG. 3a, an intaglio mold (30) is made to produce a plasmonic element having an embossed pattern.

[0055] And as shown in FIG. 3b, physical vapor deposition is performed on a mold (30) to deposit a metal thin film (31).

[0056] The deposition of the metal thin film described above includes a physical vapor deposition process carried out under high vacuum, and the physical vapor deposition process may form the metal thin film using one or more of a sputtering or evaporation process, but is not limited thereto.

[0057] Next, as shown in FIG. 3c, chloroform is applied to the metal thin film (31) to form a chloroform coating layer (32).

[0058] And as shown in Fig. 3d, UV exposure is performed for the dissociation of chlorine atoms in chloroform and the formation of metal chloride.

[0059] Next, as shown in FIG. 3e, a step of peeling off the adhesive tape (33) is performed to remove the unnecessary upper metal film excluding the metal within the nanostructure on the intaglio mold (30).

[0060] Then, a UV-curing imprint step is performed for the formation of polymer nanopatterns and the selective deposition of metal.

[0061] The mechanism for achieving the chemical reaction occurring during the process according to the present invention is shown in FIG. 1, and is achieved through energy supply in a non-spontaneous reaction via UV exposure and a spontaneous reaction.

[0062] This method utilizes the fact that while chemical bonding between metal and chlorine atoms does not occur spontaneously upon the simple application of chloroform molecules, supplying light energy equivalent to or greater than the bond-dissociation energy of chlorine atoms in chloroform molecules causes the chlorine atoms to separate, triggering a spontaneous reaction between the metal and chlorine atoms to form a bond.

[0063] Subsequently, a small amount of additional light energy is supplied during the UV-curing nanoimprinting process to form a bond between the polymer and the metal chloride, thereby forming an artificial chemical bond between the polymer and the metal.

[0064] Here, the deposition of the metal thin film utilizes a physical vapor deposition process that has strong linearity and poor adhesion to the substrate, thereby minimizing the deposition of the metal thin film on the sides of the mold and improving the fidelity of the finished flexible device.

[0065] In addition, UV light with a wavelength of ~385 nm and a power level above a certain threshold is used for the decomposition of chlorine atoms in chloroform, and for UV exposure to form bonds with the polymer, an appropriate power is applied to prevent the dissociation of metal and chlorine atoms, thereby controlling the wavelength and power according to the situation to avoid causing unintended additional reactions.

[0066] A UV-cured nanoimprint-based selective deposition process method for improving the metal transfer rate on such polymer patterns facilitates metal separation and enables the fabrication of plasmonic devices by including a process for forming chemical bonds between the UV resin and the metal.

[0067] This process is designed to improve the transfer rate of metal thin films and ensure high fidelity by using chloroform to form chemical bonds between metal and chlorine atoms, as well as chemical bonds between the metal and the polymer.

[0068] And the above chloroform treatment involves inducing a halogenation reaction between the metal and chlorine atoms in the metal thin film, and a process in which chlorine atoms are dissociated after the chloroform molecules undergo a photodissociation reaction.

[0069] Here, the photodissociation reaction can be achieved by exposing UV light of 385 nm or less to a metal thin film coated with chloroform.

[0070] And the metal undergoes the separation of chlorine atoms and the formation of metal chloride through the photodissociation reaction of chloroform.

[0071] And UV exposure after the photodissociation process aims to provide additional enthalpy for the formation of polymer-metal chemical bonds.

[0072] Then, a plasmonic device is fabricated by forming an integral structure in which a metal thin film is selectively deposited on a cured resin pattern through UV exposure in the UV-NIL process.

[0073] Figure 4 is a schematic diagram showing the effects of chloroform treatment and photodissociation reaction on the transfer rate of metal.

[0074] (a) shows an SEM image of a plasmonic device fabricated without chloroform treatment or UV exposure, (b) shows an image of a device fabricated with chloroform treatment but without UV exposure, and (c) shows an image of a device fabricated with both chloroform treatment and UV exposure, demonstrating that chloroform treatment and the photodegradation process help improve the metal transfer rate of the fabricated plasmonic device.

[0075] Figure 5 is a graph of the optical amplification characteristics of a plasmonic device fabricated according to the present invention.

[0076] This demonstrates that a device with superior performance can be fabricated by the present invention compared to the optical amplification performance of a plasmonic device fabricated by a thermal nanoimprint process.

[0077] The UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern according to the present invention, as described above, enables efficient selective deposition of a metal on a polymer structure by forming a chemical bond between a UV-curing resin and a metal thin film using the halogenation of the metal.

[0078] As explained above, it will be understood that the present invention is implemented in a modified form without departing from the essential characteristics of the invention.

[0079] Therefore, the described embodiments should be considered in an illustrative rather than a limiting sense, and the scope of the invention is defined by the claims rather than the foregoing description, and all variations within the equivalent scope should be interpreted as being included in the invention. Explanation of the symbols

[0080] 30. Mold 31. Metal thin film 32. Chloroform coating layer 33. Adhesive tape

Claims

Claim 1 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, comprising: a step of manufacturing an intaglio mold for fabricating a plasmonic element having an embossed pattern; a step of depositing a metal thin film on the mold; a step of applying a chemical reaction control material on the metal thin film; a step of supplying light energy greater than the bond-dissociation energy of atoms to the chemical reaction control material through a UV exposure process; a step of removing the metal thin film; and a step of performing a UV-curing imprint for the formation of a polymer nano pattern and selective deposition of a metal; wherein the chemical reaction control material is used to induce a halogenation reaction between chlorine atoms on the metal thin film and the metal to form a metal-chlorine chemical bond, and the UV exposure process is characterized by irradiating UV light of 385 nm or less onto the metal thin film coated with the chemical reaction control material. Claim 2 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, characterized in that, in the step of depositing a metal thin film according to claim 1, a physical deposition process including sputtering or evaporation is used. Claim 3 delete Claim 4 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, characterized in that, in claim 1, the chemical reaction control material is chloroform. Claim 5 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, characterized in that, in claim 4, the dissociation of chlorine atoms in chloroform and the induction of a metal halogenation reaction occur, thereby causing the separation of chlorine atoms and a spontaneous reaction between the metal and chlorine atoms to form a bond. Claim 6 delete Claim 7 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, characterized in that, in the step of removing the metal thin film, an adhesive tape peeling process is used to remove the unnecessary upper metal thin film excluding the metal within the nanostructure on the intaglio mold. Claim 8 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, characterized in that, in the step of supplying light energy greater than the bond-dissociation energy of atoms to a chemical reaction control material in a UV exposure process, chlorine atoms are separated from the molecules of the chemical reaction control material, the separated chlorine atoms meet with the metal of the metal thin film to spontaneously form a metal chloride, and additional light energy is supplied in a UV-curing imprint process to promote the formation of a chemical bond between the metal chloride and oxygen atoms on the polymer, so that the chemical bond between the metal halide and the polymer is stronger than the bond strength between the mold and the metal, thereby allowing the metal within the intaglio mold to be selectively deposited onto a specific nano pattern of the polymer. Claim 9 A UV-curing nanoimprint-based selective deposition process method for improving the metal transfer rate on a polymer pattern, characterized in that, in claim 1, the negative mold is fabricated from Si and the metal thin film is made of Ag.

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