Nanoimprint photoresist and its preparation method

Abstract

This application discloses a nanoimprint photoresist and its preparation method, relating to the field of nanoimprint technology. The preparation method includes: providing a cage-like polysilsesquioxane oligomer, a monofunctional monomer, an organosilane, an additive, a photoinitiator, and an organic solvent; and preparing the nanoimprint photoresist using the cage-like polysilsesquioxane oligomer, the monofunctional monomer, the organosilane, the additive, the photoinitiator, and the organic solvent. This application aims to solve the problem that existing photoresists have relatively low etch resistance and etching selectivity, thus affecting optical performance.

Description

Technical Field

[0001] This application relates to the field of nanoimprint technology, and in particular to a nanoimprint photoresist and its preparation method. Background Technology

[0002] Nano-imprint lithography (NIL) is a process that transfers the microstructure of a master template onto a wafer. For ultraviolet nanoimprint lithography, the performance of the photoresist significantly affects performance parameters such as the replication accuracy of the imprinted pattern, the pattern defect rate, and the etching selectivity during pattern transfer to the substrate. Especially after photopolymerization, excess photoresist needs to be removed using plasma etching; therefore, the photopolymerized photoresist must also meet the requirement of resistance to oxygen plasma etching. However, current nanoimprint lithography photoresists suffer from drawbacks such as low adhesion to the substrate, leading to structural detachment when there is little residual photoresist, resulting in photoresist residue on the template after imprinting; high adhesion to the template resist, affecting the high fidelity and resolution of the imprinted pattern; and low etch resistance and selectivity, thus impacting optical performance. Summary of the Invention

[0003] This application provides a nanoimprint photoresist and its preparation method, aiming to solve the problem that existing photoresists have low etch resistance and low etching selectivity, which affects optical performance.

[0004] In a first aspect, this application provides a nanoimprint photoresist, which comprises: cage-like polysilsesquioxane oligomers, monofunctional monomers, organosilanes, additives, photoinitiators, and organic solvents.

[0005] Secondly, this application provides a method for preparing a nanoimprint photoresist, the method comprising:

[0006] We provide cage-type polysilsesquioxane oligomers, monofunctional functional monomers, organosilanes, additives, photoinitiators, and organic solvents.

[0007] The nanoimprint photoresist was prepared using the cage-like polysilsesquioxane oligomer, monofunctional monomer, organosilane, additives, photoinitiator, and organic solvent.

[0008] This application provides a nanoimprint photoresist and its preparation method. It utilizes a cage-like polysilsesquioxane oligomer and a monofunctional monomer with an alicyclic structure to react, resulting in a nanoimprint photoresist with both a POSS and alicyclic structures. This enhances the nanoimprint photoresist's resistance to oxygen plasma etching, provides a high etching selectivity during ICP dry etching, and also enables the prepared nanoimprint photoresist to have low surface energy, high Young's modulus, and high hardness. Furthermore, it exhibits good demolding effect, fidelity, and resolution during the imprinting process. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the chemical reaction of a fluorinated cage-like silsesquioxane oligomer provided in the embodiments of this application;

[0011] Figure 2 This is a schematic flowchart of an embodiment of a method for preparing nanoimprint photoresist provided in this application.

[0012] Figure 3 This is a schematic flowchart of another embodiment of a method for preparing a nanoimprint photoresist provided in this application.

[0013] Figure 4 This is a schematic flowchart of another embodiment of a method for preparing a nanoimprint photoresist provided in this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0016] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0017] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0018] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0019] For ultraviolet nanoimprint lithography (UVNIM), the main components and application properties of the matching photoresists are often unclear, causing difficulties for users and resulting in high costs. These photoresists also often present a problem: template cleaning. Due to the micro- and nano-structures of the template surface, the photoresist can easily remain on the template after imprinting due to wedging between the photoresist and the template, or due to the high van der Waals forces generated by the template's large surface area, thus contaminating the template. Therefore, after a period of imprinting, the template needs to be cleaned before it can be used again. However, once existing photoresists remain on the template, these residues are difficult to completely remove using chemical methods, and the residues accumulate with each imprinting cycle, eventually rendering the expensive template unusable due to excessive residue. The ultraviolet nanoimprint photoresist must meet eight performance requirements in the imprinting and etching processes: low viscosity of the photoresist, low surface roughness of the photoresist on the substrate, low ultraviolet exposure during photoresist curing, greater adhesion of the photoresist to the substrate than to the template, high fidelity and high resolution of the imprinted pattern, no photoresist residue on the template after imprinting, excellent etch resistance of the photoresist, and rapid one-time cleaning of defective patterns.

[0020] Therefore, the key to UV nanoimprinting lies in the photoresist, whose performance significantly impacts the replication accuracy of the imprinted pattern, the pattern defect rate, and the etching selectivity during pattern transfer to the substrate. Currently, UV nanoimprinting photoresists suffer from drawbacks such as low adhesion to the substrate, leading to structural detachment when there is little residual photoresist, resulting in photoresist residue on the template after imprinting; high adhesion to soft template adhesives, affecting the high fidelity and resolution of the imprinted pattern; and relatively low etch resistance and etching selectivity. Therefore, UV nanoimprinting photoresists must possess the property of undergoing photocuring and cross-linking under UV irradiation, as well as low viscosity, easy flow, and good wetting properties, allowing the photoresist to quickly fill the gap between the template and the substrate through capillary action. Simultaneously, the photoresist must have low surface energy, primarily to prevent it from adhering to the template surface after UV exposure and curing, thus avoiding affecting the quality of pattern transfer. Another requirement is that the cured photoresist must be resistant to oxygen plasma etching. After photocuring, excess photoresist must be removed using a plasma etching process. In summary, developing a photoresist suitable for ultraviolet nanoimprinting, capable of rapid imprinting and etching, and able to be quickly and thoroughly cleaned once the template is contaminated, is of great significance.

[0021] This application provides a nanoimprint photoresist comprising a cage-like polysilsesquioxane oligomer, a monofunctional monomer with an alicyclic structure, an organosilane, an additive, a photoinitiator, and an organic solvent.

[0022] Among them, cage-like polysilsesquioxane oligomers can be oligomers of polyhedral oligomeric silsesquioxane (POSS). The POSS structure consists of an inorganic core composed of an alternating Si-O silicon-oxygen skeleton, shaped like a "cage," with three-dimensional dimensions between 1-3 nm. The distance between Si atoms is 0.5 nm, and the distance between R groups is 1.5 nm, classifying it as a nanocompound. Monofunctional monomers can include alicyclic monofunctional monomers. Monofunctional monomers with alicyclic structures are a class of monofunctional monomers obtained through different carbon skeleton arrangements in organic chemistry classification. Their molecules contain carbon rings composed of three or more carbon atoms linked together. The bonds between two adjacent carbon atoms within the ring can be single, double, or triple bonds, and the number of rings can be one or more. Differences in ring structure and number result in different chemical properties for monofunctional monomers with alicyclic structures. The carbon atoms on the ring can also be attached to chemical functional groups, such as amino, carboxyl, hydroxyl, carbon-carbon double bonds, and carbon-carbon triple bonds. Different functional groups result in different chemical properties. These monofunctional monomers include alicyclic hydrocarbons and their derivatives.

[0023] For example, the monofunctional monomer can be a monofunctional monomer with an alicyclic structure. In the reaction with cage-like polysilsesquioxane oligomers, this alicyclic structure can be introduced onto the side chain. Since ICP dry etching uses plasma etching, specifically neutral gases such as CF4, these gases are introduced into the gas discharge region. Through ionization or decomposition, free radicals are generated. These free radicals are highly reactive and easily come into contact with the material on the etched surface, causing a chemical reaction and material stripping. Compounds with alicyclic structures have stable electronic structures, low electron cloud density, and high plasma resistance. The active free radicals generated by ionization are unlikely to capture electrons, thus preventing structural damage. Conversely, silicon is a highly reactive element and is easily attacked by free radicals in a plasma atmosphere, resulting in a chemical reaction. The generated product, SiF4, is a gas that leaves the silicon surface, causing a sharp decrease in surface product concentration and accelerating the reaction. Ultimately, this results in a high etching selectivity for the nanoimprint photoresist.

[0024] For example, the organosilane can be an ultraviolet radiation (UV) reactive organosilane, which can promote the adhesion of the nanoimprint photoresist to the substrate and prevent the photoresist film from detaching from the substrate during the imprinting process. Because it can participate in the reaction, it also prevents the migration of free coupling agents. Additives play a wetting and leveling role, ensuring that the photoresist can effectively wet the substrate during spin coating on the wafer surface, resulting in a film layer with uniform thickness and a smooth surface. Photoinitiators are mainly used to adjust the curing rate and degree of curing of the system. Solvents are mainly used to adjust the viscosity and evaporation rate of the system, facilitating control of the film thickness and surface smoothness during spin coating.

[0025] This application provides a nanoimprint photoresist that utilizes a cage-like polysilsesquioxane oligomer and a monofunctional monomer to produce a POSS and alicyclic structure, thereby enhancing its resistance to oxygen plasma etching. It exhibits a high etching selectivity during inductively coupled plasma (ICP) dry etching and also possesses low surface energy, high Young's modulus, and high hardness, resulting in excellent demolding performance, fidelity, and resolution during the imprinting process. Furthermore, the nanoimprint photoresist has a viscosity of 3.5-15 mPa·s, exhibiting good fluidity, excellent substrate wetting and leveling effects, and can produce uniformly thick films with good stability.

[0026] In some embodiments, the nanoimprint photoresist further includes multifunctional acrylate monomers and / or multifunctional vinyl ether monomers. Because the nanoimprint photoresist contains multifunctional acrylate monomers and / or multifunctional vinyl ether monomers, the compatibility between the components in the system is enhanced, resulting in a photoresist with good stability.

[0027] For example, the multifunctional acrylate monomer can be a difunctional acrylate monomer, and the multifunctional vinyl ether monomer can be a difunctional vinyl ether monomer, which can enhance the compatibility of the system and adjust the film-forming properties and adhesion to the substrate.

[0028] In some embodiments, the content of cage-type polysilsesquioxane oligomers is 15%-30% by weight, for example: 15%, 20%, 25%, 30%, etc.; the content of monofunctional functional monomers is 5%-10%, the content of polyfunctional acrylate monomers and / or polyfunctional vinyl ether monomers is 5%-10%, for example: 5%, 7%, 8%, 10%, etc.; the content of organosilanes is 1%-5%, for example: 1%, 2%, 3%, 5%, etc.; the content of additives is 1%-3%, for example: 1%, 2%, 3%, etc.; the content of photoinitiators is 1%-3%, for example: 1%, 2%, 3%, etc.; and the content of organic solvents is 50%-70%, for example: 50%, 55%, 60%, 70%, etc.

[0029] It should be noted that if the nanoimprint photoresist does not include multifunctional acrylate monomers and / or multifunctional vinyl ether monomers, the content of this material can be replaced by organic solvents.

[0030] Since nanoimprint photoresist is primarily composed of cage-like polysilsesquioxane oligomers, its proportion is relatively high. Monofunctional monomers are used to provide alicyclic structures, so their proportion is relatively low. Polyfunctional acrylate monomers and / or polyfunctional vinyl ether monomers are used to enhance the system's compatibility and can also adjust the system's film-forming properties and adhesion to the substrate, so their proportion is relatively low. Organosilanes, additives, and photoinitiators mainly play an auxiliary role, so they only need to be added in appropriate amounts. Organic solvents are mainly used to adjust the system's viscosity and evaporation rate, so their proportion is relatively high.

[0031] For example, the cage-like polysilsesquioxane oligomer can account for 25% of the nanoimprint photoresist, the monofunctional functional monomer can account for 8% of the nanoimprint photoresist, the polyfunctional acrylate monomer and / or polyfunctional vinyl ether monomer can account for 7% of the nanoimprint photoresist, the organosilane can account for 3% of the nanoimprint photoresist, the additive can account for 1% of the nanoimprint photoresist, the photoinitiator can account for 1% of the nanoimprint photoresist, and the organic solvent can account for 55% of the nanoimprint photoresist.

[0032] In some embodiments, the cage-like polysilsesquioxane oligomer may be selected from any one or more of the following: fluorinated cage-like silsesquioxane oligomers, cage-like silsesquioxane oligomers with epoxy groups on the side chains, cage-like silsesquioxane oligomers with acryloyloxypropyl groups on the side chains, and cage-like silsesquioxane oligomers with methacryloyloxypropyl groups on the side chains.

[0033] like Figure 1 As shown, exemplarily, cage-like polysilsesquioxane oligomers can be prepared by reacting silane coupling agents including acid-bonded structures and silane coupling agents including fluorine-based structures to obtain fluorine-modified cage-like silsesquioxane oligomers (MA-F-POSS). The nanoimprint photoresist provided in this application introduces fluorine-modified cage-like silsesquioxane oligomers, thereby giving the photoresist low surface energy, high Young's modulus, and high hardness, resulting in good release effect, fidelity, and resolution during the imprinting process.

[0034] It should be noted that the cage-like polysilsesquioxane oligomer can be any oligomer that can provide a POSS structure. Preferably, the best effect is achieved when using fluorine-modified cage-like silsesquioxane oligomers, which can make the nanoimprint photoresist have low surface energy, high Young's modulus and high hardness, and have good demolding effect, fidelity and resolution during the imprinting process.

[0035] In some embodiments, the monofunctional monomer may be selected from any one or more of the following: isoborneol methacrylate, 2-methyl-2-methacrylate adamantane ester, 3-hydroxy-1-methacrylate adamantane ester, 2,6-sunolactone-5-methacrylate norborneol ester, (1'-methylcyclopentyl-1-cyclopentyl) methacrylate, α-(γ-butyrolactone) methacrylate, 3-oxo-4,10-dioxa-tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-hydroxy-1-methacrylate adamantane ester, (2,2-dimethyl-1,3-dioxolane-4-methyl) methacrylate, methacrylate [bis(2,2-dimethyl-1,3-dioxolane)-4-methyl] ester, norbornene, norbornene-maleic anhydride, norbornene-sulfur dioxide, and vinyl ether-maleic anhydride ester.

[0036] For example, the monofunctional monomers provided above all include alicyclic structures, which can react with cage-like silsesquioxane oligomers to make the nanoimprint photoresist have both POSS and alicyclic structures, thereby enhancing its resistance to oxygen plasma etching and exhibiting a high etching selectivity during ICP dry etching.

[0037] In some embodiments, the multifunctional vinyl ether monomers include one or more of the following: hydroxybutyl vinyl ether, triethylene glycol divinyl ether, 1,4-cyclohexyldiethanol divinyl ether, and butyl vinyl ether; the multifunctional acrylate monomers include one or more of the following: 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, di(trimethylolpropane)tetraacrylate, 4(ethoxylated)pentaerythritol tetraacrylate, and pentaerythritol tetraacrylate.

[0038] For example, the multifunctional vinyl ether monomers and / or multifunctional acrylate monomers provided above can enhance the compatibility of the components in the nanoimprint photoresist, and can also adjust the film-forming properties and adhesion to the substrate of the system.

[0039] In some embodiments, the organosilane may be selected from any one or more of γ-(methacryloyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriethoxysilane, γ-(methacryloyloxy)propyltriethoxysilane, methacryloyloxymethyltriethoxysilane, 3-methacryloyloxypropyltri(methoxyethoxy)silane, methacryloyloxypropyltri(dimethylsiloxane)silane, γ-(acryloyloxy)propyltrimethoxysilane, γ-(acryloyloxy)propyltriethoxysilane, allyltri(trimethylsiloxy)silane, 1,3-bis(3-methacryloyloxypropyl)tetra(trimethylsiloxy)disiloxane, and N-(3-acryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane.

[0040] For example, the organosilanes provided above can all promote adhesion to the substrate, prevent the film from detaching from the substrate during the imprinting process, and prevent the migration of free coupling agents.

[0041] In some embodiments, the adjuvant may be any one or more of BYK333, BYK3550, BYK302, BYK3500, BYK3530, BYK3570, Deqian 407, Deqian 410, Deqian 411, Deqian 432, Deqian 435, and Deqian 455.

[0042] For example, the additives provided above can all play a role in wetting and leveling, so that the photoresist can effectively wet the substrate when spin-coated on the wafer surface, resulting in a film layer with uniform thickness and smooth surface.

[0043] In some embodiments, the photoinitiator may be any one or more of the following: photoinitiator 1173, photoinitiator 1176, photoinitiator 184, TPO, TPO-L, photoinitiator 127, photoinitiator 369, ITX, BDK, photoinitiator 819, photoinitiator 754, photoinitiator 380, BMF, ANTHRACURE™ UVS-1331, ANTHRACURE™ UVS-1101, Easepi 6992, Easepi 1176, and Easepi 250.

[0044] For example, the photoinitiators provided above can all be used to adjust the curing rate and curing degree of nanoimprint photoresist.

[0045] In some embodiments, the organic solvent may be any one or more of propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, ethyl acetate, N,N-dimethylformamide, methyl ethyl ketone, dimethyl sulfoxide, and butyl acetate.

[0046] For example, the organic solvents provided above can all adjust the viscosity and evaporation rate of the nanoimprint photoresist, thereby facilitating the control of the film thickness and surface smoothness during spin coating.

[0047] It should be noted that the various cage-like polysilsesquioxane oligomers, monofunctional functional monomers, polyfunctional acrylate monomers and / or polyfunctional vinyl ether monomers, organosilanes, additives, photoinitiators and organic solvents mentioned above are generally different in molecular weight, functional group or hardness, but they all belong to the same class of substances.

[0048] See Figure 2 , Figure 2 This is a schematic flowchart of an embodiment of a method for preparing nanoimprint photoresist provided in this application. The preparation method includes steps S101 and S102.

[0049] Step S101: Provide cage-type polysilsesquioxane oligomers, monofunctional functional monomers, organosilanes, additives, photoinitiators, and organic solvents, wherein the monofunctional functional monomers have alicyclic structures.

[0050] It should be noted that specific embodiments of cage-type polysilsesquioxane oligomers, monofunctional functional monomers, organosilanes, additives, photoinitiators, and organic solvents can be found in the above embodiments and will not be repeated here.

[0051] Step S102: Nanoimprint photoresist is prepared using cage-type polysilsesquioxane oligomers, monofunctional monomers, organosilanes, additives, photoinitiators, and organic solvents.

[0052] This application provides a method for preparing a nanoimprint photoresist. It utilizes a cage-like polysilsesquioxane oligomer and a monofunctional monomer to react, resulting in a nanoimprint photoresist with both POSS and alicyclic structures. This enhances the nanoimprint photoresist's resistance to oxygen plasma etching, exhibits a high etching selectivity during ICP dry etching, and also results in a nanoimprint photoresist with low surface energy, high Young's modulus, and high hardness. During the imprinting process, it demonstrates good demolding effect, fidelity, and resolution. Furthermore, the nanoimprint photoresist has a viscosity of 3.5-15 mPa·s, exhibits good fluidity, excellent substrate wetting and leveling effects, and can produce a film of uniform thickness with good stability.

[0053] In some embodiments, step S101, where organosilane, additives, and photoinitiator are added to a first container, and the mixture is stirred and mixed evenly, allowed to stand, and then filtered to obtain the filtered nanoimprint photoresist, may include sub-steps S201 and S202, such as... Figure 3 As shown.

[0054] Sub-step S201: The cage-type polysilsesquioxane oligomer, the monofunctional monomer and the organic solvent are added to the first container and stirred and mixed evenly based on the first stirring parameters.

[0055] Sub-step S202: Add organosilane, additives, and photoinitiator to the first container, and stir and mix evenly based on the second stirring parameters. Let stand and filter to obtain the filtered nanoimprint photoresist.

[0056] For example, the first stirring parameters include a first stirring temperature, a first stirring speed, and a first stirring duration. The first stirring temperature is 23°C, which can be between 21°C and 25°C. Preferably, the first stirring temperature is 23°C, which is the temperature inside the container during stirring. The first stirring speed is 600 r / min, and the first stirring duration is 30 minutes. During the stirring and mixing process, the organic solvent, fluorinated cage-like silsesquioxane oligomer, monofunctional acrylate, and polyfunctional acrylate can be added to the container and slowly stirred at 600 r / min for 30 minutes to ensure complete dissolution and obtain a homogeneous solution. The liquid temperature in the container is maintained between 21°C and 25°C throughout the process.

[0057] For example, the second stirring parameters include a second stirring temperature, a second stirring speed, and a second stirring duration. The second stirring temperature is 23°C, but can be between 21°C and 25°C. Preferably, the second stirring temperature is 23°C, which is the temperature inside the container during stirring. The second stirring speed is 1000 r / min, and the second stirring duration is 30 minutes. While stirring to ensure uniform mixing, the stirring speed is adjusted to 1000 r / min, and then the organosilane, additives, and photoinitiator are slowly added. Stirring continues for 30 minutes, maintaining the liquid temperature in the container between 21°C and 25°C throughout the process. After stirring, the mixture is allowed to stand for 30 minutes, and then filtered under pressure using a 0.22 μm organic filter to obtain a colorless and transparent nanoimprint photoresist.

[0058] It should be noted that during the mixing process, inert gases such as nitrogen can be introduced into the container to reduce the oxygen concentration inside. The choice can be made based on the actual situation.

[0059] In some embodiments, providing a cage-like polysilsesquioxane oligomer in step S101 may include sub-steps S301 and S303, such as... Figure 4 As shown.

[0060] Sub-step S301: The first silane coupling agent, the second silane coupling agent, the first alkaline catalyst and the first solvent are added to the second container and stirred and mixed evenly. The first silane coupling agent has an acid bond structure and the second silane coupling agent has a fluorine group structure.

[0061] Sub-step S302: The mixture in the second container is subjected to rotary evaporation, washing and drying to obtain silsesquioxane product.

[0062] Sub-step S303: The silsesquioxane product is subjected to condensation treatment to obtain fluorine-modified cage-like silsesquioxane oligomers.

[0063] The first silane coupling agent has an acid bond structure, the second silane coupling agent has a fluorine group structure, the first alkaline catalyst is 25% tetramethylammonium hydroxide, ammonia or sodium hydroxide, used to catalyze the reaction, and the first solvent can be isopropanol, n-propanol, dimethyl carbonate or propylene glycol methyl ether.

[0064] For example, the first silane coupling agent may be γ-methacryloxypropyltrimethoxysilane (KH570) or other silane coupling agents with acid bond structures; the second silane coupling agent may be dodecafluoroheptylpropyltrimethoxysilane (G502), heptadecafluorodecyltrimethoxysilane, nonafluorohexyltrimethoxysilane, trifluoropropyltrimethylsiloxane or other silane coupling agents with fluorine group structures.

[0065] In some embodiments, the content of the first silane coupling agent is 5%-15% by weight, for example: 5%, 10%, 12%, 15%, etc.; the content of the second silane coupling agent is 15%-20%, for example: 15%, 17%, 18%, 20%, etc.; the content of the first alkaline catalyst is 5-10%, for example: 5%, 7%, 8%, 10%, etc.; and the content of the first solvent is 60-75%, for example: 60%, 67%, 70%, 75%, etc.

[0066] For example, the content of the first silane coupling agent can be 15%, the content of the second silane coupling agent can be 15%, the content of the first alkaline catalyst can be 5%, and the content of the first solvent can be 65%.

[0067] In some embodiments, a first alkaline catalyst and a first solvent are added to a second container and stirred until homogeneous; a first silane coupling agent and a first solvent are added to a third container and stirred until homogeneous; a second silane coupling agent and a first solvent are added to a fourth container and stirred until homogeneous; the mixtures from the third container and the fourth container are added dropwise alternately to the second container and stirred until homogeneous. Because the first and second silane coupling agents have significant polarity differences, their compatibility when mixed is not very good, and they also have large density differences, resulting in stratification. Therefore, adding them separately allows for a better homogeneous reaction between the first and second silane coupling agents and the system.

[0068] For example, 120g of isopropanol solvent and 9.4g of alkaline catalyst (25% tetramethylammonium hydroxide) can be added to a single-necked round-bottom flask, and a magnetic stirrer can be added for magnetic stirring. Separately, 20ml of the first solvent, isopropanol, and 15g of KH570 are placed in a dropping funnel, and 28.9g of G502 is placed in another dropping funnel. While stirring, the liquids from the two dropping funnels are slowly added dropwise to the flask, completing the addition in about half an hour. After the solutions in the dropping funnels have been added, the mixture is magnetically stirred at 25°C for 2-3 hours. After the reaction is complete, the mixture is rotary evaporated to remove the isopropanol solvent, yielding a pale yellow oily liquid with a certain viscosity. Then, about 200ml of toluene is added to dissolve the rotary evaporated product, and the mixture is washed with saturated brine to remove the alkaline catalyst until pH=7 (generally 3-5 times). After drying with anhydrous magnesium sulfate and filtering, the solvent toluene is removed by rotary evaporation to obtain a colorless, viscous product, which is a silsesquioxane product.

[0069] In some embodiments, the silsesquioxane product, the second alkaline catalyst, and the second solvent are added to a fifth container and stirred until homogeneous. The mixture in the fifth container is then distilled and refluxed, followed by rotary evaporation, washing, and drying to obtain a fluorinated cage-like silsesquioxane oligomer. Thus, a fluorinated cage-like silsesquioxane oligomer can be obtained by condensing the silsesquioxane product.

[0070] The second alkaline catalyst can be 10% tetramethylammonium hydroxide, ammonia, or sodium hydroxide, used to catalyze the reaction, and the second solvent can be toluene or other solvents that can be used for distillation reflux.

[0071] For example, 100 ml of toluene, 3 g of alkaline catalyst (10% tetramethylammonium hydroxide), and the silsesquioxane product can be added to a single-necked round-bottom flask, followed by magnetic stirring. The system is then heated using a separatory distillation apparatus to remove water. The temperature is then raised to 120°C, allowing the toluene to undergo a re-condensation reaction at reflux temperature. After approximately 3 hours of reflux, the reaction is essentially complete. The alkalinity is then removed by washing with saturated brine, followed by dehydration with anhydrous magnesium sulfate. After filtration and rotary evaporation, a colorless, viscous, oily liquid is obtained, which is the oligomeric silsesquioxane with photosensitive side chains, specifically a fluorinated cage-like silsesquioxane oligomer. The photosensitive side chains are segments with UV-curable carbon-carbon double bonds.

[0072] The following specific examples illustrate the preparation method of the fluorine-modified cage-like silsesquioxane oligomers provided in this application.

[0073] Example a:

[0074] Add 20g of isopropanol and 5g of alkaline catalyst (25% tetramethylammonium hydroxide) to a single-necked round-bottom flask, add a magnetic stir bar, and stir magnetically. Separately, place 40g of isopropanol and 15g of KH570 in one dropping funnel, and 20g of G502 in another dropping funnel. While stirring, slowly add the liquids from the two dropping funnels dropwise into the reactor, completing the addition in about half an hour. After the solutions in the dropping funnels have been added, stir magnetically at 25°C and react for 2-3 hours. Then, perform rotary evaporation, washing, and drying to obtain a silsesquioxane product. Finally, perform condensation treatment on the silsesquioxane product to obtain a fluorinated cage-like silsesquioxane oligomer. The fluorinated cage-like silsesquioxane oligomer prepared by the above-mentioned mass ratio reacts faster and has higher hardness.

[0075] Example b:

[0076] Add 37.5 g of n-propanol and 5 g of alkaline catalyst (25% tetramethylammonium hydroxide) to a single-necked round-bottom flask, add a magnetic stir bar, and stir magnetically. Separately, place 37.5 g of n-propanol and 5 g of KH570 in a dropping funnel, and 15 g of heptadecafluorodecyltrimethoxysilane in another dropping funnel. While stirring, slowly add the liquids from both dropping funnels dropwise into the reactor, completing the addition in about half an hour. After the solutions in the dropping funnels have been added, stir magnetically at 25°C and react for 2-3 hours. Then, perform rotary evaporation, washing, and drying to obtain a silsesquioxane product. Finally, perform condensation treatment on the silsesquioxane product to obtain a fluorinated cage-like silsesquioxane oligomer. The fluorinated cage-like silsesquioxane oligomer prepared using the above mass ratio of the raw materials is softer, and the reaction rate is slightly slower.

[0077] Example c:

[0078] Add 35g of propylene glycol methyl ether and 10g of alkaline catalyst (25% sodium hydroxide) to a single-necked round-bottom flask, add a magnetic stir bar, and stir magnetically. Separately, place 30g of propylene glycol methyl ether and 8g of KH570 in a dropping funnel, and 17g of nonafluorohexyltrimethoxysilane in another dropping funnel. While stirring, slowly add the liquids from both dropping funnels dropwise into the reactor, completing the addition in about half an hour. After the solutions in the dropping funnels have been added, stir magnetically at 25°C and react for 2-3 hours. Then, perform rotary evaporation, washing, and drying to obtain a silsesquioxane product. Finally, perform condensation treatment on the silsesquioxane product to obtain a fluorinated cage-like silsesquioxane oligomer. The fluorinated cage-like silsesquioxane oligomer prepared by the above-mentioned mass ratio reacts faster and has higher hardness.

[0079] Example d:

[0080] Add 40g of dimethyl carbonate and 7g of alkaline catalyst (25% sodium hydroxide) to a single-necked round-bottom flask, add a magnetic stir bar, and stir magnetically. Separately, place 31g of dimethyl carbonate and 6g of KH570 in one dropping funnel, and 16g of nonafluorohexyltrimethoxysilane in another dropping funnel. While stirring, slowly add the liquids from both dropping funnels dropwise into the reactor, completing the addition in about half an hour. After the solutions in the dropping funnels have been added, stir magnetically at 25°C and react for 2-3 hours. Then, perform rotary evaporation, washing, and drying to obtain a silsesquioxane product. Finally, perform condensation treatment on the silsesquioxane product to obtain a fluorinated cage-like silsesquioxane oligomer. The fluorinated cage-like silsesquioxane oligomer prepared using the above mass ratio of raw materials reacts faster and has higher hardness.

[0081] The preparation method and performance of the nanoimprint photoresist provided in this application are illustrated below through specific embodiments.

[0082] Example 1:

[0083] (1) Add 65g of propylene glycol methyl ether acetate, 22g of self-made fluorine-modified cage-like silsesquioxane oligomer, 3g of 2-methyl-2-methacrylate adamantane ester, 2g of 2,6-sulonolactone-5-methacrylate norbornene ester, and 5g of 1,6-hexanediol diacrylate to a container and stir slowly at 600r / min for 30 minutes to completely dissolve the system and obtain a homogeneous solution. During the process, maintain the liquid temperature in the container at 23℃.

[0084] (2) Adjust the speed to 1000 r / min, then slowly add 1g γ-(methacryloyloxy)propyltrimethoxysilane, 1g BYK333 and 1g photoinitiator 1176, and continue stirring for 30 minutes, maintaining the liquid temperature in the container at 23℃ during the process.

[0085] (3) After stirring, let stand for 30 minutes, and then filter under pressure with a 0.22μm organic filter to obtain colorless and transparent nanoimprint photoresist.

[0086] Therefore, in Example 1, the amount of cage-type polysilsesquioxane oligomer is 22%, the amount of monofunctional functional monomer is 5%, the amount of polyfunctional acrylate monomer is 5%, the amount of organosilane is 1%, the amount of additive is 1%, the amount of photoinitiator is 1%, and the amount of organic solvent is 65%.

[0087] Example 2:

[0088] (1) Add 50g of dipropylene glycol methyl ether acetate, 19g of self-made fluorine-modified cage-like silsesquioxane oligomer, 6g of isobornyl methacrylate, 4g of 3-hydroxy-1-methacrylic adamantane ester, and 10g of triethylene glycol divinyl ether to a container and stir slowly at 600r / min for 30 minutes to completely dissolve the system and obtain a homogeneous solution. During the process, maintain the liquid temperature in the container at 23℃.

[0089] (2) Adjust the speed to 1000r / min, then slowly add 5g vinyltrimethoxysilane, 3g BYK3550 and 3g photoinitiator 184, and continue stirring for 30 minutes, maintaining the liquid temperature in the container at 23℃ during the process.

[0090] (3) After stirring, let stand for 30 minutes, and then filter under pressure with a 0.22μm organic filter to obtain colorless and transparent nanoimprint photoresist.

[0091] Therefore, in Example 2, the amount of cage-type polysilsesquioxane oligomer is 19%, the amount of monofunctional functional monomer is 10%, the amount of polyfunctional acrylate monomer is 10%, the amount of organosilane is 5%, the amount of additive is 3%, the amount of photoinitiator is 3%, and the amount of organic solvent is 50%.

[0092] Example 3:

[0093] (1) Add 70g of dipropylene glycol methyl ether acetate, 15g of cage-like silsesquioxane oligomer with epoxy groups on the side chain, 2g of 2,6-sulonolactone-5-methacrylate norbornane ester, 3g of 3-hydroxy-1-methacrylate adamantane ester, and 5g of pentaerythritol triacrylate to a container and stir slowly at 600r / min for 30 minutes to completely dissolve the system and obtain a homogeneous solution. During the process, maintain the liquid temperature in the container at 23℃.

[0094] (2) Adjust the speed to 1000 r / min, then slowly add 3g of methacryloyloxypropyltris(dimethylsiloxane), 1g of BYK3570 and 1g of TPO, and continue stirring for 30 minutes, maintaining the liquid temperature in the container at 23°C during the process.

[0095] (3) After stirring, let stand for 30 minutes, and then filter under pressure with a 0.22μm organic filter to obtain colorless and transparent nanoimprint photoresist.

[0096] Therefore, in Example 3, the amount of cage-type polysilsesquioxane oligomer is 15%, the amount of monofunctional functional monomer is 5%, the amount of polyfunctional acrylate monomer is 5%, the amount of organosilane is 3%, the amount of additive is 1%, the amount of photoinitiator is 1%, and the amount of organic solvent is 70%.

[0097] Example 4:

[0098] (1) Add 60g of dipropylene glycol methyl ether acetate, 20g of cage-like silsesquioxane oligomer with methacryloyloxypropyl side chain, 4g of vinyl ether-maleic anhydride ester, 4g of 3-hydroxy-1-methacrylic acid adamantane ester, and 7g of pentaerythritol tetraacrylate to a container and stir slowly at 600r / min for 30 minutes to completely dissolve the system and obtain a homogeneous solution. During the process, maintain the liquid temperature in the container at 23℃.

[0099] (2) Adjust the speed to 1000 r / min, then slowly add 1 g γ-(acryloyloxy)propyltrimethoxysilane, 2 g Deqian 455 and 2 g photoinitiator 754, and continue stirring for 30 minutes, maintaining the liquid temperature in the container at 23°C during the process.

[0100] (3) After stirring, let stand for 30 minutes, and then filter under pressure with a 0.22μm organic filter to obtain colorless and transparent nanoimprint photoresist.

[0101] Therefore, in Example 4, the amount of cage-type polysilsesquioxane oligomer is 20%, the amount of monofunctional functional monomer is 8%, the amount of polyfunctional acrylate monomer is 7%, the amount of organosilane is 1%, the amount of additive is 2%, the amount of photoinitiator is 2%, and the amount of organic solvent is 60%.

[0102] The performance of the nanoimprint photoresist provided in the above embodiments was tested, and the experimental data are shown in Table 1. Related technologies provide specifications for nanoimprint photoresists, which are compared with the nanoimprint template provided in the above embodiments to confirm whether the nanoimprint template provided in the above embodiments meets the specifications.

[0103] Table 1

[0104]

[0105] As shown in Table 1, the nanoimprint stencil adhesive provided in this application conforms to the standard values ​​for appearance (colorless and transparent liquid), viscosity (3.5-15 mPa·s), hardness after curing (60-75D), surface droplet angle (greater than or equal to 100°), and Young's modulus (greater than or equal to 1 GPa). Taking silicon as an example, the etching selectivity conforms to the standard value (greater than or equal to 1). Taking silicon as an example, because the etching selectivity is greater than 1, it has a high etching selectivity during ICP dry etching, allowing for rapid and thorough removal of excess photoresist after photocuring using plasma etching. Simultaneously, the prepared nanoimprint photoresist possesses low surface energy, high Young's modulus, and high hardness, resulting in good release effect, fidelity, and resolution during the imprinting process.

[0106] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A nanoimprint photoresist, characterized in that, The nanoimprint photoresist is prepared from the following raw materials: cage-type polysilsesquioxane oligomer, monofunctional functional monomer, polyfunctional acrylate monomer and / or polyfunctional vinyl ether monomer, organosilane, additives, photoinitiator and organic solvent, wherein the monofunctional functional monomer has an alicyclic structure. The contents of the cage-like polysilsesquioxane oligomer are 15%-30% by weight, the contents of the monofunctional monomer are 5%-10%, the contents of the polyfunctional acrylate monomer and / or the polyfunctional vinyl ether monomer are 5%-10%, the contents of the organosilane are 1%-5%, the contents of the additives are 1%-3%, the contents of the photoinitiator are 1%-3%, and the contents of the organic solvent are 50%-70%.

2. The nanoimprint photoresist according to claim 1, characterized in that, The cage-like polysilsesquioxane oligomer is at least one of the following: fluorine-modified cage-like silsesquioxane oligomer, cage-like silsesquioxane oligomer with epoxy groups on the side chain, cage-like silsesquioxane oligomer with acryloyloxypropyl groups on the side chain, and cage-like silsesquioxane oligomer with methacryloyloxypropyl groups on the side chain.

3. The nanoimprint photoresist according to claim 1, characterized in that, The monofunctional monomer is at least one of the following: isoborneol methacrylate, 2-methyl-2-methacrylate adamantane ester, 3-hydroxy-1-methacrylate adamantane ester, 2,6-sunolactone-5-methacrylate norborneol ester, (1'-methylcyclopentyl-1-cyclopentyl) methacrylate, α-(γ-butyrolactone) methacrylate, 3-oxo-4,10-dioxa-tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-hydroxy-1-methacrylate adamantane ester, (2,2-dimethyl-1,3-dioxolane-4-methyl) methacrylate, methacrylate [bis(2,2-dimethyl-1,3-dioxolane)-4-methyl] ester, norbornene, norbornene-maleic anhydride, norbornene-sulfur dioxide, and vinyl ether-maleic anhydride ester.

4. The nanoimprint photoresist according to claim 1, characterized in that, The multifunctional vinyl ether monomer is at least one of hydroxybutyl vinyl ether, triethylene glycol divinyl ether, 1,4-cyclohexyldiethanol divinyl ether, and butyl vinyl ether; The multifunctional acrylate monomer is at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, di(trimethylolpropane)tetraacrylate, 4(ethoxylated)pentaerythritol tetraacrylate, and pentaerythritol tetraacrylate.

5. The nanoimprint photoresist according to claim 1, characterized in that, The organosilane is at least one of γ-(methacryloyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriethoxysilane, γ-(methacryloyloxy)propyltriethoxysilane, methacryloyloxymethyltriethoxysilane, 3-methacryloyloxypropyltri(methoxyethoxy)silane, methacryloyloxypropyltri(dimethylsiloxane)silane, γ-(acryloyloxy)propyltrimethoxysilane, γ-(acryloyloxy)propyltriethoxysilane, allyltri(trimethylsiloxy)silane, 1,3-bis(3-methacryloyloxypropyl)tetra(trimethylsiloxy)disiloxane, and N-(3-acryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane.

6. The nanoimprint photoresist according to claim 1, characterized in that, The additive is at least one of BYK333, BYK3550, BYK302, BYK3500, BYK3530, BYK3570, Deqian 407, Deqian 410, Deqian 411, Deqian 432, Deqian 435, and Deqian 455.

7. The nanoimprint photoresist according to claim 1, characterized in that, The photoinitiator is at least one of photoinitiator 1173, photoinitiator 1176, photoinitiator 184, TPO, TPO-L, photoinitiator 127, photoinitiator 369, ITX, BDK, photoinitiator 819, photoinitiator 754, photoinitiator 380, BMF, ANTHRACURE™ UVS-1331, ANTHRACURE™ UVS-1101, Easepi 6992, and Easepi 250.

8. The nanoimprint photoresist according to claim 1, characterized in that, The organic solvent is at least one of propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, ethyl acetate, N,N-dimethylformamide, methyl ethyl ketone, dimethyl sulfoxide, and butyl acetate.

9. A method for preparing a nanoimprint photoresist as described in any one of claims 1-8, characterized in that, The method includes: Provided are cage-type polysilsesquioxane oligomers, monofunctional functional monomers, organosilanes, additives, photoinitiators and organic solvents, wherein the monofunctional functional monomers have alicyclic structures; The nanoimprint photoresist was prepared using the cage-like polysilsesquioxane oligomer, monofunctional monomer, organosilane, additives, photoinitiator, and organic solvent.

10. The preparation method according to claim 9, characterized in that, The nanoimprint photoresist is prepared using the cage-like polysilsesquioxane oligomer, monofunctional monomer, organosilane, additives, photoinitiator, and organic solvent, comprising: The cage-shaped polysilsesquioxane oligomer, the monofunctional monomer, and the organic solvent are added to the first container and stirred and mixed evenly based on the first stirring parameters. The organosilane, additives, and photoinitiator are added to the first container and stirred and mixed evenly based on the second stirring parameters. The mixture is then allowed to stand and filtered to obtain the filtered nanoimprint photoresist.

11. The preparation method according to claim 10, characterized in that, The first stirring parameters include a first stirring temperature, a first stirring speed, and a first stirring duration. The first stirring temperature is 21℃-25℃, the first stirring speed is 600r / min, and the first stirring duration is 30 minutes. The second stirring parameters include a second stirring temperature, a second stirring speed, and a second stirring duration. The second stirring temperature is 21℃-25℃, the second stirring speed is 1000r / min, and the second stirring duration is 30 minutes.

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