Fluorine-containing polymer, preparation method thereof and ArF immersed photoresist prepared from polymer

Abstract

The invention relates to the technical field of photoetching materials, and particularly discloses a fluorine-containing polymer, a preparation method thereof and an ArF immersed photoresist prepared from the polymer. The fluorine-containing polymer comprises, by mol%, 5-15 mol% of a monomer A, 55-80 mol% of a monomer B and 15-30 mol% of a monomer C. The monomer A is a methacrylate monomer whose side chain is lactone, the monomer B is a methacrylate monomer whose side chain contains a protective group, and the monomer C is a methacrylate monomer whose side chain contains fluorine. The preparation method comprises the steps of dissolution, heating reaction, purification, drying and the like. The fluorine-containing polymer can be used for preparing an ArF immersed photoresist, a water-resistant layer with excellent hydrophobicity can be formed on the surface of the photoresist, the fluorine-containing polymer has good compatibility with the ArF immersed photoresist, and the developing performance of the photoresist is remarkably improved.

Description

Technical Field

[0001] The present application relates to the technical field of photolithography materials, and more specifically, to a fluorine-containing polymer and a preparation method thereof, and an ArF immersion photoresist prepared using the polymer. Background Art

[0002] ArF immersion lithography is the leading lithography process in advanced manufacturing. It combines multiple exposure processes with a resolution of 45-7nm and is mainly used for fine pattern transfer in semiconductor manufacturing. ArF immersion lithography continues the ArF light source and adds a water medium between the photoresist and the lithography machine lens, which improves the resolution and focal depth of the photoresist.

[0003] During immersion lithography, component exchange occurs between photoresist and water (water penetrates into photoresist, causing small molecules in the swollen photoresist to diffuse into water), resulting in water and lithography machine lens contamination and damage, photoresist performance degradation and increased defects. Therefore, forming a water-resistant coating on the surface of photoresist has become an effective method for immersion lithography.

[0004] With respect to the above-mentioned related technologies, the inventors found that the introduction of water-resistant components in the prior art resulted in the compatibility between ArF immersion photoresist components being unable to meet the requirements of process production applications, resulting in the final ArF immersion photoresist having poor development performance.

[0005] Fluorine-containing polymers have low polarizability, small intermolecular forces, and low surface energy. They can spontaneously phase separate and migrate to the surface in solutions or polymer systems to form a surface fluorine-containing layer, which has an excellent hydrophobic effect and has broad application prospects in the field of water-resistant coatings on photoresist surfaces.

[0006] The low surface energy fluorinated polymer and ArF photoresist are blended, and the fluorinated polymer is enriched on the surface of the photoresist film during the spin coating process to form a water-resistant coating. The following requirements need to be met: 1. Fluorine-containing polymers and photoresist solutions have good compatibility, no stratification, no agglomeration; 2. The formed water-resistant layer is highly hydrophobic; 3. It has affinity to the developer and the exposed area can be dissolved in the developer.

[0007] In view of this, it is necessary to develop a fluorinated polymer with good performance for ArF immersion photoresist. Summary of the invention

[0008] In order to improve the compatibility of components of ArF immersion photoresist, increase its contact angle, and improve the developing performance, the present application provides a fluorine-containing polymer and a preparation method thereof, and an ArF immersion photoresist prepared using the polymer.

[0009] In a first aspect, the present application provides a fluorine-containing polymer, using the following technical solution: A fluorine-containing polymer, comprising the following components, calculated in mol%, 5-15 mol% of A monomer, 55-80 mol% of B monomer and 15-30 mol% of C monomer; The A monomer is a methacrylate monomer with a lactone side chain; The B monomer is a methacrylate monomer having a protective group on the side chain; The C monomer is a methacrylate monomer containing fluorine in the side chain.

[0010] By adopting the above technical solution, the fluorine-containing side chain in the C monomer has significant hydrophobic properties and can show alkaline solubility under specific conditions, which can form a hydrophobic layer on the surface of the photoresist, increase the contact angle between the photoresist and water, and at the same time help the photoresist to better dissolve in the developer during the development process, thereby effectively improving its development performance.

[0011] The lactone of monomer A and the protective group of monomer B in the fluorinated polymer are beneficial to improving the compatibility of the fluorinated polymer and the photoresist film-forming resin and improving the stability of the photoresist solution; the hydrophobicity and low surface energy of the fluorine chain of monomer C help the fluorinated polymer migrate to the surface of the photoresist to form a water-resistant layer; the lactone of monomer A provides affinity for the alkaline developer, making the development more complete.

[0012] The three monomers A, B, and C are combined in a specific proportion to form a fluorine-containing polymer, which can form a certain matching and interaction force in the molecular structure, so that the fluorine-containing polymer of the present application can enhance the compatibility of the various components of the photoresist when used to prepare the photoresist, significantly improve the overall performance of the photoresist, reduce the phase separation phenomenon that may occur during the use of the photoresist, ensure the stability and consistency of the photoresist, and thus improve the development performance.

[0013] Optionally, the A monomer has the following general structure: Wherein R1 is H or CH3, and the structure of R2 is any one of the following structures: Wherein R3 is an alkyl substituted hydrocarbon.

[0014] Optionally, the structure of monomer A is as follows: They are 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 2-carboxy-4-norbornyl lactone-5-methylacrylate, and 2-oxo-2-[(5-oxo-4-oxatricyclo[4.2.1.03,7]non-2-yl)oxy]ethyl methacrylate.

[0015] Optionally, the B monomer has the following general structure: Wherein R1 is H or CH3, R4, R5, and R6 are alkyl or aliphatic cyclic groups, and R4, R5, and R6 may form a cyclic structure, such as any one of 1-methylcyclopentyl methacrylate, 1-ethylcyclopentyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-ethylcyclohexyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, adamantyl methanol acrylate, adamantyl methanol methacrylate, 2-methyl 2-adamantyl methacrylate, 2-methyl 2-adamantyl acrylate, 2-ethyl 2-adamantyl methacrylate, 2-ethyl 2-adamantyl acrylate, 2-isopropyl 2-adamantyl methacrylate, 2-isopropyl 2-adamantyl acrylate, 3-hydroxy-1-adamantyl acrylate, and 3-hydroxy-1-adamantyl methacrylate; or 5-(2-carboxylic acid tert-butyl) norbornyl methacrylate, 5-(2-carboxylic acid tert-butyl) norbornyl acrylate, 5-(2-carboxylic acid methylcyclohexyl) norbornyl methacrylate, 5-(2-carboxylic acid methylcyclohexyl) norbornyl acrylate, 5-(2-carboxylic acid 1-methylcyclohexyl) norbornyl methacrylate, 5-(2-carboxylic acid 1-methylcyclohexyl) norbornyl acrylate, 5-(2-carboxylic acid 1-ethylcyclopentyl) norbornyl methacrylate, 5-(2-carboxylic acid 1-ethylcyclopentyl) norbornyl acrylate, methacrylic acid any one of 5-(2-carboxylic acid 1-ethylcyclopentyl) norbornyl, 5-(2-carboxylic acid 1-ethylcyclohexyl) norbornyl, methacrylate 5-(2-carboxylic acid 1-ethylcyclohexyl) norbornyl, acrylate 5-(2-carboxylic acid 1-ethylcyclohexyl) norbornyl, methacrylate 5-(2-carboxylic acid 2-butyrolactone) norbornyl, acrylate 5-(2-carboxylic acid 2-butyrolactone) norbornyl, methacrylate 5-(2-carboxylic acid 2-caprolactone) norbornyl, and acrylate 5-(2-carboxylic acid 2-caprolactone) norbornyl.

[0016] Optionally, the C monomer has the following general structural formula: Wherein R1 is H or CH3; R3 is a fluorine-containing alkyl group, such as any one of tert-butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate, octafluoropentyl methacrylate, hexafluoroisopropyl methacrylate and ethyl 2-((2,2,3,3,3-pentafluoropropionyl)oxy)methacrylate.

[0017] In a second aspect, the present application provides a method for preparing a fluorine-containing polymer, using the following technical solution: A method for preparing a fluorine-containing polymer comprises the following steps: S1. According to the ratio, monomer A, monomer B, monomer C and initiator are dissolved in a first solvent to obtain a solution A; S2. The solution A is added dropwise to the first solvent under N2 protective atmosphere at a temperature of 60-90 ° C and stirred for 2-6 hours, and then heated for 10-20 hours to obtain a solution B; S3. Add the solution B into the second solvent and filter it by suction, and then dry it under vacuum to obtain the fluorine-containing polymer.

[0018] By adopting the above technical solution, a fluorine-containing polymer with good performance can be prepared through a simple process without complicated preparation conditions.

[0019] Optionally, the first solvent is any one of tetrahydrofuran, butanone, butyl acetate, and propylene glycol methyl ether acetate; the second solvent is any one of petroleum ether, n-hexane, and n-heptane.

[0020] In a third aspect, a fluorine-containing polymer of the present application can be used to prepare ArF immersion photoresist, using the following technical solution: An ArF immersion photoresist, the raw materials comprising the fluorine-containing polymer according to any one of claims 1 to 4, and also comprising an ArF photoresist film-forming polymer, a photoacid generator, an alkaline additive and a solvent; The mass ratio of the fluorine-containing polymer to the ArF photoresist film-forming polymer is (0.5-10):100; The mass ratio of the photoacid generator to the ArF photoresist film-forming polymer is (0.5-15):100; The mass ratio of the alkaline additive to the ArF photoresist film-forming polymer is (0.05-5):100; The mass ratio of the solvent to the ArF photoresist film-forming polymer is 100:(2-10).

[0021] By adopting the above technical solution, the fluorine-containing polymer of the present application is applied to the preparation of ArF immersion photoresist, and the overall performance of the photoresist can be optimized by adjusting the ratio of the fluorine-containing polymer to other components. The hydrophobicity of the fluorine-containing polymer helps to improve the water resistance and developing ability of the photoresist. In the immersion lithography process, it can effectively reduce the component exchange between the photoresist and water, improve the performance of the photoresist, and thus obtain a higher quality lithography pattern.

[0022] Optionally, the photoacid generator is selected from any one or more of diazonium salts, sulfonium salts, iodonium salts, sulfonyldiazomethane, N-hydroxyimide sulfonates, imide sulfonates, nitrobenzylbenzenesulfonates and sulfonic acid oxime esters.

[0023] Optionally, the photoacid generator is triphenylsulfonium perfluorobutanesulfonate, 2-(adamantane-1-carbonyl)oxy)-1,1-difluoroethanesulfonic acid (4-methylphenyl) diphenylsulfonium salt, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium camphorsulfonate, diphenyliodonium perfluoro-1-butanesulfonate, diphenyliodonium perfluorooctanesulfonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonate, bis(4-tert-butylphenyl)iodonium 4-(4-tert-butylphenyl)iodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium perfluorooctanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium perfluoro-1-butanesulfonate, triphenylsulfonium perfluorooctanesulfonate, 4-methoxyphenylphenyl iodonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium perfluorooctanesulfonate, p-tolyldiphenylsulfonium perfluoro-1-butanesulfonate, p-tolyldiphenylsulfonium camphorsulfonate, 2,4,6-trimethylphenyldiphenyl 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 1-(2-naphthoylmethyl)thiolate trifluoromethanesulfonate, 4-hydroxy-1-naphthoyldimethylsulfonium trifluoromethanesulfonate, N-(phenylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)succinimide, N-(perfluoro-1-butanesulfonic acid)succinimide, N-(perfluorooctanesulfonic acid)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(perfluorooctanesulfonic acid)phthalimide imide, N-(trifluoromethylsulfonyloxy)-5-norbornene-2,3-dicarboxy imide, N-(perfluoro-1-butanesulfonic acid)-5-norbornene-2,3-dicarboxy imide, N-(perfluorooctanesulfonic acid)-5-norbornene-2,3-dicarboxy imide, N-(trifluoromethylsulfonyloxy)naphthyl methylene imide, N-(perfluoro-1-butanesulfonic acid)naphthyl methylene imide, N-(perfluorooctanesulfonic acid)naphthyl methylene imide, any one or more of N-(10-camphorsulfonyloxy)naphthyl methylene imide.

[0024] By adopting the above technical scheme, the photoacid generator selected in the present application has good thermal stability and chemical stability, which is beneficial to improving the uniformity of the prepared ArF immersion photoresist. It can quickly generate acid during the exposure process, thereby initiating a chemical reaction of the photoresist to form a clear pattern.

[0025] Optionally, the alkaline additive is selected from any one or more of tetra-n-butylammonium hydroxide, tetrabutylammonium acetate, trioctylamine, 2,6-diisopropylaniline and triethanolamine.

[0026] By adopting the above technical solution, the addition of alkaline additives can neutralize the acid generated by the photoresist during the development process, preventing the acid from excessively corroding the photolithographic pattern. By selecting the above specific substances as alkaline additives, the development process can be further controlled to improve the fidelity and resolution of the pattern.

[0027] Optionally, the solvent is selected from any one or more of propylene glycol methyl ether acetate, ethyl lactate, ethyl acetate, 2-heptanone, ethylene glycol monomethyl ether acetate, cyclohexanone, methyl pentanol, γ-butyrolactone and 3-ethoxypropionic acid.

[0028] By adopting the above technical scheme and selecting the above specific substances as solvents, the solubility and coating performance of the photoresist can be optimized. These solvents not only help the photoresist to form a uniform film on the substrate, but also improve the adhesion between the photoresist and the substrate, thereby ensuring the formation of a stable water-resistant layer during the development process.

[0029] Optionally, the solvent is selected from any one or more of propylene glycol methyl ether acetate, ethyl lactate, ethyl acetate, 2-heptanone, ethylene glycol monomethyl ether acetate, cyclohexanone, methyl pentanol, γ-butyrolactone, and 3-ethoxypropionic acid.

[0030] In a fourth aspect, the present application provides the same ArF immersion photoresist film, using the following technical solution: The ArF immersion photoresist of the present application is formed into an ArF immersion photoresist film through coating and baking, and a pattern is obtained through exposure and development.

[0031] By adopting the above technical solution, the ArF immersion photoresist of the present application is used for coating, baking film formation and exposure and development processes, thereby further improving the development ability and pattern quality of the photoresist.

[0032] In summary, this application has the following beneficial effects: 1. The present application prepares ArF immersion photoresist by copolymerizing a methacrylate monomer with a lactone side chain, a methacrylate monomer with a protective group on the side chain, and a methacrylate monomer with a fluorine-containing side chain into a fluorine-containing polymer, and using the fluorine-containing polymer as an additive to effectively form a water-resistant coating on the surface of the photoresist, while improving the compatibility between the components of the ArF immersion photoresist.

[0033] 2. The lactone of monomer A and the protective group of monomer B in the fluorinated polymer are beneficial to improving the compatibility of the fluorinated polymer and the photoresist film-forming resin and improving the stability of the photoresist solution; the hydrophobicity and low surface energy of the fluorine chain of monomer C help the fluorinated polymer migrate to the surface of the photoresist to form a water-resistant layer; the lactone of monomer A provides affinity for the alkaline developer, making the development more complete.

[0034] 3. The present application can prepare a fluorine-containing polymer for ArF immersion photoresist with good performance through a simple process without complicated preparation conditions. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in combination with embodiments, application examples and comparative examples.

[0036] raw material Unless otherwise specified, the raw materials used in the embodiments, application examples and comparative examples of this application are all commercially available products, as shown in Table 1: Table 1 CAS Chinese name 254900-07-7 2-Carboxy-4-norbornyl lactone-5-methacrylate 347886-81-1 2-Carboxy-4-norbornyl lactone-5-acetoxy methacrylate 195000-66-9 2-Carbonyl-tetrahydrofuran-3-hydroxy-methacrylate 1092693-73-6 tert-Butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate 355-93-1 Octafluoropentyl methacrylate 3063-94-3 Hexafluoroisopropyl methacrylate 938459-25-7 2-((2,2,3,3,3-pentafluoropropionyl)oxy)ethyl methacrylate 178889-45-7 1-Methylcyclopentyl methacrylate 266308-58-1 1-Ethylcyclopentyl methacrylate 274248-09-8 1-Ethylcyclohexyl methacrylate 251909-25-8 1-Ethylcyclohexyl acrylate 177080-67-0 2-Methyl-2-adamantyl methacrylate 115372-36-6 3-Hydroxy-1-adamantyl methacrylate Preparation of ArF photoresist film-forming polymer The ArF photoresist film-forming polymer is composed of three monomers: 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 2-methyl-2-adamantyl methacrylate and 3-hydroxy-1-adamantyl methacrylate. The preparation method thereof comprises the following steps: S1. Weigh 8.51 g of 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate, 7.03 g of 2-methyl-2-adamantyl methacrylate, 4.21 g of 3-hydroxy-1-adamantyl methacrylate and 0.99 g of azobisisobutyronitrile, and dissolve them in 30 g of butanone to obtain a polymer solution A; S2. In a 100 ml four-necked flask equipped with a stirrer, a condenser and a thermometer, 30 g of butanone was added, and under the protection of N2, the mixture was heated to 80 °C with stirring, and the polymer solution A was slowly added dropwise. The addition was completed over 3 h, and the reaction was continued for 14 h before stopping and cooling to room temperature to obtain a polymer solution B; S3. The polymer solution B was added dropwise to 300 g of methanol to produce a precipitate. After standing, the upper liquid was removed and tetrahydrofuran was added until the precipitate was completely dissolved to obtain a polymer solution C; S4. The polymer solution C was added dropwise to 300 g of methanol, filtered to obtain a white polymer powder, which was then dried in vacuum. Example

[0037] Example 1 A fluorine-containing polymer, comprising 0.0125 mol A monomer, 0.075 mol B monomer and 0.0375 mol C monomer, wherein A monomer is 2-Carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, monomer B is 1-Ethylcyclohexyl methacrylate, C monomer is tert-Butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25° C., prepare corresponding molar masses of 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 1-ethylcyclohexyl methacrylate and tert-butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate as polymer monomers, weigh 1.03 g of azobisisobutyronitrile as an initiator and mix with the polymer monomers, and dissolve with 75 g of tetrahydrofuran to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 3h. The reaction was continued for 13h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0038] Example 2 A fluorine-containing polymer, comprising 0.0187 mol A monomer, 0.075 mol B monomer and 0.0313 mol C monomer, wherein A monomer is 2-Carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, monomer B is 1-Ethylcyclohexyl acrylate, C monomer is Octafluoropentyl methacrylate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25° C., prepare corresponding molar masses of 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 1-ethylcyclohexyl acrylate, and octafluoropentyl methacrylate as polymer monomers, weigh 1.03 g of azobisisobutyronitrile as an initiator and mix with the polymer monomers, and dissolve with 72 g of tetrahydrofuran to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 3h. The reaction was continued for 14h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0039] Example 3 A fluorine-containing polymer, comprising 0.0062 mol A monomer, 0.0813 mol B monomer and 0.0375 mol C monomer, wherein A monomer is 2-Carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, monomer B is 1-Methylcyclopentyl methacrylate, C monomer is Hexafluoroisopropyl methacrylate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25° C., prepare corresponding molar masses of 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 1-methylcyclopentyl methylacrylate and hexafluoroisopropyl methacrylate as polymer monomers, weigh 1.03 g of azobisisobutyronitrile as an initiator and mix with the polymer monomers, and dissolve with 65 g of butanone to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 3h. The reaction was continued for 14h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0040] Example 4 A fluorine-containing polymer, comprising 0.0125 mol A monomer, 0.0813 mol B monomer and 0.028 mol C monomer, wherein A monomer is 2-Carboxy-4-norbornyl lactone-5-acetoxy methacrylate, monomer B is 1-Ethylcyclopentyl methacrylate, C monomer is Ethyl 2-((2,2,3,3,3-pentafluoropropionyl)oxy)methacrylate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25° C., prepare corresponding molar masses of 2-carboxy-4-borneol-5-acetoxymethylacrylate, 1-ethylcyclopentyl methacrylate and ethyl 2-((2,2,3,3,3-pentafluoropropionyl)oxy)methacrylate as polymer monomers, weigh 1.03 g of azobisisobutyronitrile as an initiator and mix with the polymer monomers, and dissolve with 72 g of butanone to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 3h. The reaction was continued for 14h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0041] Example 5 A fluorine-containing polymer, comprising 0.0125 mol A monomer, 0.0813 mol B monomer and 0.0313 mol C monomer, wherein A monomer is 2-Carboxyl-4-norbornyl lactone-5-methylacrylate, monomer B is 1-Methylcyclopentyl methacrylate, C monomer is Hexafluoroisopropyl methacrylate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25°C, prepare corresponding molar masses of 2-carboxy-4-borneol-5-methylacrylate, 1-methylcyclopentyl methacrylate and hexafluoroisopropyl methacrylate as polymer monomers, weigh 1.03 g of azobisisobutyronitrile as an initiator and mix with the polymer monomers, and dissolve with 67 g of butanone to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 3h. The reaction was continued for 14h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0042] Example 6 A fluorine-containing polymer, comprising 0.0125 mol A monomer, 0.2 mol B monomer and 0.0375 mol C monomer, wherein A monomer is 2-Carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, monomer B is 1-Ethylcyclohexyl methacrylate, C monomer is tert-Butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25° C., 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 1-ethylcyclohexyl methacrylate and tert-butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate of accurately corresponding molar masses are used as polymer monomers, 1.03 g of azobisisobutyronitrile is weighed as an initiator and mixed with the polymer monomers, and dissolved in 75 g of tetrahydrofuran to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 2h. The reaction was continued for 20h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0043] Example 7 A fluorine-containing polymer, comprising 0.0125 mol of monomer A, monomer B and monomer C, wherein monomer A is 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, monomer B is 1-ethylcyclohexyl methacrylate, and monomer C is tert-butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate; The method for preparing the fluorine-containing polymer comprises the following steps: S1. At 25° C., 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 1-ethylcyclohexyl methacrylate and tert-butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate of accurately corresponding molar masses are used as polymer monomers, 1.03 g of azobisisobutyronitrile is weighed as an initiator and mixed with the polymer monomers, and dissolved in 75 g of tetrahydrofuran to obtain solution A; S2. In a 250mL four-necked flask equipped with a stirrer, a condenser and a thermometer, 38g of tetrahydrofuran was added, and under the protection of N2, the solution A was slowly added dropwise, and the addition was completed over 6h. The reaction was continued for 10h and then stopped, and the solution was cooled to room temperature to obtain a solution B; S3. Solution B was added dropwise to an excess of n-hexane to produce a precipitate, which was filtered to obtain a powdered polymer; S4. The powder polymer is dissolved in tetrahydrofuran and added dropwise to an excess of n-hexane to produce a precipitate. The powder polymer is filtered off and vacuum dried to obtain the precipitate.

[0044] Application Examples A fluorine-containing polymer of the present application is used for preparing ArF immersion photoresist.

[0045] Application Example 1 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.2g of triphenylsulfonium perfluorobutanesulfonate, 0.1g of the fluorine-containing polymer obtained in Example 1, and 0.02g of trioctylamine into 70g of propylene glycol methyl ether acetate.

[0046] Application Example 2 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.2g of triphenylsulfonium perfluorobutanesulfonate, 0.08g of the fluorine-containing polymer obtained in Example 2, and 0.02g of trioctylamine into 70g of propylene glycol methyl ether acetate.

[0047] Application Example 3 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.25g of triphenylsulfonium perfluorobutanesulfonate, 0.12g of the fluorine-containing polymer obtained in Example 3, and 0.02g of trioctylamine into 70g of propylene glycol methyl ether acetate.

[0048] Application Example 4 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.2g of triphenylsulfonium perfluorobutanesulfonate, 0.1g of the fluorine-containing polymer obtained in Example 4, and 0.02g of trioctylamine into 70g of propylene glycol methyl ether acetate.

[0049] Application Example 5 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.2g of triphenylsulfonium perfluorobutanesulfonate, 0.13g of the fluorine-containing polymer obtained in Example 5, and 0.02g of trioctylamine into 70g of propylene glycol methyl ether acetate.

[0050] Application Example 6 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.0125g of triphenylsulfonium perfluorobutanesulfonate, 0.0125g of the fluorine-containing polymer obtained in Example 6, and 0.00125g of trioctylamine into 25g of propylene glycol methyl ether acetate.

[0051] Application Example 7 An ArF immersion photoresist is prepared by adding 2.5g of ArF photoresist film-forming polymer, 0.375g of triphenylsulfonium perfluorobutanesulfonate, 0.25g of the fluorine-containing polymer obtained in Example 7, and 0.125g of trioctylamine into 125g of propylene glycol methyl ether acetate.

[0052] Comparative Example Comparative Example 1 An ArF immersion photoresist is prepared by adding 2.5g of the ArF photoresist film-forming polymer, 0.2g of triphenylsulfonium perfluorobutanesulfonate and 0.02g of trioctylamine into 70g of propylene glycol methyl ether acetate.

[0053] Performance testing The following performance test was performed on the ArF immersion photoresists corresponding to Example 1-7 and Comparative Example 1, and the test results are recorded in Table 2.

[0054] 1. Contact angle test: The prepared photoresist was coated and baked at 110° C. for 60 seconds to obtain a photoresist film, and the water contact angle of the film was tested by using a water drop.

[0055] Instrument: KRUSS contact angle tester.

[0056] 2. Photoresist defects: Test method: After coating the photoresist prepared above, bake at 110°C for 60s, expose with an immersion photolithography machine, and obtain a photoresist pattern after post-baking and development; Use a scanning electron microscope to observe whether the photolithography pattern has defects.

[0057] 3. Photoacid generator leaching: Photoacid generator leaching detection instrument in water: LC-MS-MS (brand / model Agilent).

[0058] Table 2 According to the performance test results in Table 2, it can be seen that when a fluorine-containing polymer of the present application is used to prepare ArF immersion photoresist, it has a large contact angle with water before development, which indicates that the fluorine-containing polymer of the present application can migrate to the surface of the film to form a water-repellent layer. After development, the contact angle with water decreases, which indicates that the fluorine-containing polymer of the present application has good affinity for the developer, and the developer containing the fluorine-containing polymer has no development residue.

[0059] It can be seen from the anion leaching concentration test of photoacid generation in Examples 1-7 and Comparative Example 1 that the leaching value of the photoresist component in water is very small, which indicates that the fluorine-containing polymer can successfully inhibit the precipitation of the photoresist component, effectively prevent the water lithography machine lens from being contaminated and damaged, and ensure the excellent performance of the photoresist.

[0060] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A fluorine-containing polymer, characterized in that In mol%, it comprises the following components: 5-15 mol% of A monomer, 55-80 mol% of B monomer and 15-30 mol% of C monomer; The A monomer is a methacrylate monomer with a lactone side chain; The B monomer is a methacrylate monomer having a protective group on the side chain; The C monomer is a methacrylate monomer containing fluorine in the side chain.

2. The fluorinated polymer according to claim 1, characterized in that The general structure of the A monomer is as follows: Wherein R1 is H or CH3, and the structure of R2 is any one of the following structures: Wherein R3 is an alkyl substituted hydrocarbon, such as any one of 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate, 2-carboxy-4-norbornyl lactone-5-methylacrylate and 2-oxo-2-[(5-oxo-4-oxatricyclo[4.2.1.03,7]non-2-yl)oxy]ethyl methacrylate.

3. The fluorine-containing polymer according to claim 1, characterized in that The general structural formula of the B monomer is as follows: Wherein R1 is H or CH3, R4, R5, and R6 are alkyl or aliphatic cyclic groups, and R4, R5, and R6 may form a cyclic structure, such as any one of 1-methylcyclopentyl methacrylate, 1-ethylcyclopentyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-ethylcyclohexyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, adamantyl methanol acrylate, adamantyl methanol methacrylate, 2-methyl 2-adamantyl methacrylate, 2-methyl 2-adamantyl acrylate, 2-ethyl 2-adamantyl methacrylate, 2-ethyl 2-adamantyl acrylate, 2-isopropyl 2-adamantyl methacrylate, 2-isopropyl 2-adamantyl acrylate, 3-hydroxy-1-adamantyl acrylate, and 3-hydroxy-1-adamantyl methacrylate; or 5-(2-carboxylic acid tert-butyl) norbornyl methacrylate, 5-(2-carboxylic acid tert-butyl) norbornyl acrylate, 5-(2-carboxylic acid methylcyclohexyl) norbornyl methacrylate, 5-(2-carboxylic acid methylcyclohexyl) norbornyl acrylate, 5-(2-carboxylic acid 1-methylcyclohexyl) norbornyl methacrylate, 5-(2-carboxylic acid 1-methylcyclohexyl) norbornyl acrylate, 5-(2-carboxylic acid 1-ethylcyclopentyl) norbornyl methacrylate, 5-(2-carboxylic acid 1-ethylcyclopentyl) norbornyl acrylate, methacrylic acid any one of 5-(2-carboxylic acid 1-ethylcyclopentyl) norbornyl, 5-(2-carboxylic acid 1-ethylcyclohexyl) norbornyl, methacrylate 5-(2-carboxylic acid 1-ethylcyclohexyl) norbornyl, acrylate 5-(2-carboxylic acid 1-ethylcyclohexyl) norbornyl, methacrylate 5-(2-carboxylic acid 2-butyrolactone) norbornyl, acrylate 5-(2-carboxylic acid 2-butyrolactone) norbornyl, methacrylate 5-(2-carboxylic acid 2-caprolactone) norbornyl, and acrylate 5-(2-carboxylic acid 2-caprolactone) norbornyl.

4. The fluorine-containing polymer according to claim 1, characterized in that The C monomer structure formula is as follows: Wherein R1 is H or CH3; R3 is a fluorine-containing alkyl group, such as any one of tert-butyl 2,2-difluoro-3-(methacryloyloxy)pentanoate, octafluoropentyl methacrylate, hexafluoroisopropyl methacrylate and ethyl 2-((2,2,3,3,3-pentafluoropropionyl)oxy)methacrylate.

5. The method for preparing a fluorine-containing polymer according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. According to the ratio, monomer A, monomer B, monomer C and initiator are dissolved in a first solvent to obtain a solution A; S2. The solution A is added dropwise to the first solvent under N2 protective atmosphere at a temperature of 60-90 ° C and stirred for 2-6 hours, and then heated for 10-20 hours to obtain a solution B; S3. Add the solution B into the second solvent and filter it by suction, and then dry it under vacuum to obtain the fluorine-containing polymer.

6. An ArF immersion photoresist, characterized in that: The raw materials include the fluorine-containing polymer according to any one of claims 1 to 4, and also include ArF photoresist film-forming polymer, photoacid generator, alkaline additive and solvent; The mass ratio of the fluorine-containing polymer to the ArF photoresist film-forming polymer is (0.5-10):100; The mass ratio of the photoacid generator to the ArF photoresist film-forming polymer is (0.5-15):100; The mass ratio of the alkaline additive to the ArF photoresist film-forming polymer is (0.05-5):100; The mass ratio of the solvent to the ArF photoresist film-forming polymer is 100:(2-10).

7. The ArF immersion photoresist according to claim 6, characterized in that: The photoacid generator is selected from any one or more of diazonium salts, sulfonium salts, iodonium salts, sulfonyldiazomethane, N-hydroxyimide sulfonate, imide sulfonate, nitrobenzylbenzenesulfonate and sulfonic acid oxime esters.

8. The ArF immersion photoresist according to claim 6, characterized in that: The alkaline additive is selected from any one or more of tetra-n-butylammonium hydroxide, tetrabutylammonium acetate, trioctylamine, 2,6-diisopropylaniline and triethanolamine.

9. The ArF immersion photoresist according to claim 6, characterized in that: The third solvent is selected from any one or more of propylene glycol methyl ether acetate, ethyl lactate, ethyl acetate, 2-heptanone, ethylene glycol monomethyl ether acetate, cyclohexanone, methyl pentanol, γ-butyrolactone and 3-ethoxypropionic acid.

10. The ArF immersion photoresist according to claim 6, characterized in that: The ArF immersion photoresist is subjected to coating, baking, exposure and development to obtain a pattern.

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