Resin for anti-reflection coating with high extinction coefficient and preparation method of resin

Abstract

The invention provides resin for an anti-reflection coating with a high extinction coefficient and a preparation method of the resin, the resin is prepared by free radical polymerization of styrene, glycidyl acrylate and isopropyl methacrylate, and fused ring structures such as anthracene, fluorene and pyrene are introduced into the resin structure. The PDI of the prepared resin can be within 2.5, the molecular weight distribution is narrowed, the small molecule proportion is reduced, the sensitivity of the resin in exposure and developing solvents is further improved, and the performance requirement of a bottom anti-reflection coating in the semiconductor manufacturing process can be met.

Description

Technical Field

[0001] The invention relates to the field of matting resins, and in particular to a resin for high-extinction coefficient anti-reflection coating and a preparation method thereof. Background Art

[0002] In the semiconductor manufacturing process, the bottom anti-reflection coating (BARC) in the photoresist plays a key role in improving the resolution and pattern quality of the lithography process. Since the light intensity itself fluctuates periodically along the incident direction, there are fine sawtooth patterns on the side walls of the photoresist pattern. After the incident light hits the bottom semiconductor layer, a large amount of reflected light and scattered light will hit the side walls of the photoresist pattern, further exacerbating the sawtooth shape of the photoresist pattern grooves, leading to subsequent problems such as breakage and deformation of the photoresist grooves during exposure and development. As the feature size gradually decreases, the uneven line width and pits caused by bottom reflection and scattering have seriously affected the quality and yield of the product. There are currently two methods to solve these problems. The first is to apply an anti-reflective coating (BARC) on the bottom and then apply a photoresist layer. The anti-reflective coating has a strong light absorption effect and a high refractive index, which can greatly reduce the impact of reflected light on the side walls of the photoresist pattern. The second is a top anti-reflective coating (TARC). After applying the photoresist, a layer of coating with a refractive index equal to the square root of the photoresist refractive index is applied to eliminate standing waves and reduce the energy that cannot be absorbed by the photoresist due to reflection. Secondly. In wet etching, it also plays a role in protecting the photoresist layer from water erosion. At present, the bottom anti-reflective coating has a more obvious effect in reducing the impact on the photoresist pattern, and is also easy to remove in the subsequent process, and the process is more mature and controllable. The existing solution is composed of a polymer resin containing light-absorbing groups, a cross-linking agent, a thermal acid generator, a solvent, etc. When solidified, a cross-linked structure is formed, which is insoluble in the developer solvent and forms a stable insulation layer. Among these components, polymer resin plays a key role in the bottom anti-reflective coating. Patent CN114395068B uses p-hydroxystyrene, styrene, and methyl methacrylate to synthesize BARC resin, and adds hollow carboxylated fullerene to reduce light reflection. However, since carboxylated fullerene is a hollow black carbon powder with extremely poor solubility, it is difficult to stably form a side chain structure with the hydroxyl group on the polymer chain, and the stability of the product is also difficult to ensure. Patent CN115725216A discloses a method for synthesizing BARC resin by copolymerizing acrylic epoxy monomer, acrylic anthracene structure monomer, and methyl methacrylate. The absorption coefficient and heat resistance are improved by adjusting the proportion of anthracene structure and acrylic epoxy resin. However, since the anthracene structure monomer has poor solubility and is expensive, the cost of the prepared resin is too high, which is not conducive to large-scale industrial application. Patent CN112680052A discloses a method for preparing an anti-reflective coating composition, in which 9-anthracenecarboxylic acid small molecules are added to a matting resin to increase the extinction coefficient. The extinction coefficient is increased by adjusting the content of anthracenecarboxylic acid to achieve the purpose of absorbing light intensity. At the same time, other components such as catalysts and cross-linking agents are also introduced. Although the introduced anthracenecarboxylic acid can increase the extinction coefficient, it exists in the form of small molecules. During multiple exposure, baking and development processes, some small molecules will inevitably seep out, resulting in a decrease in the anti-reflective effect and contamination problems between photoresist resin layers. Summary of the invention

[0003] Technical problem to be solved: The present invention provides a resin for high extinction coefficient anti-reflection coating and a preparation method thereof, and prepares a resin with excellent extinction performance by free radical polymerization.

[0004] Technical solution: A resin for high extinction coefficient anti-reflection coating, the resin having a structure shown in formula (1): Wherein, z accounts for 20-80% of the total molar ratio, y+x accounts for 1-80% of the total molar ratio, and x accounts for ≤70%; Wherein, the R structure is one or more of naphthyl, anthracenyl, fluorenyl, and pyrene structures. Preferably, the monomer of the R structure is one or more of 1-naphthoic acid, 1-naphthoacetic acid, 2-naphthoacetic acid, 9-anthracenecarboxylic acid, 9-fluorenecarboxylic acid or 2-carboxypyrene monomer. Preferably, the preparation method comprises the following steps: S1. The container is dried at 80-100°C for 2h, cooled to 20-40°C and replaced with nitrogen three times, and then a reaction solvent, styrene, isopropyl methacrylate, glycidyl acrylate and an initiator are added, and a solution having a mass fraction of 40-90wt% is obtained by stirring; S2. The solution obtained in S1 was heated to 75-85°C, reacted for 8-12 hours, then cooled to 20-40°C and a precipitation solvent was added, stirred for 1-3 hours, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 is added to a dissolving solvent and the temperature is raised to 55 to 65°C to obtain a reaction solution having a mass fraction of 35 to 45 wt%; S4. Add the R structure monomer solution dropwise into the solution obtained in S3, the volume ratio of the R structure monomer solution to the solution in S4 is 2 to 5:1, react for 4 to 6 hours, then cool to 25°C to obtain a resin product. Preferably, the method for preparing the R structure monomer solution in S4 comprises the following steps: S11. The container was dried at 80-100°C for 2h and cooled to 25°C, followed by replacement of nitrogen three times; S12. Add R structure monomer, catalyst and dissolving solvent in an amount equal to that of glycidyl acrylate into the container, and obtain R structure monomer solution with a mass fraction of 30 to 40 wt% by stirring. Preferably, the reaction solvent in S1 is one or more of methanol, ethanol, isopropanol, propylene glycol methyl ether acetate, propylene glycol methyl ether, N-methylpyrrolidone, N,N-dimethylformamide, 4-methyl-2-pentanone or N,N-dimethylacetamide. Preferably, the initiator in S1 is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, dibenzoyl peroxide, tert-butyl perbenzoate or diisopropyl peroxydicarbonate, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 4-7:0.1-1:2-8, and the amount of the initiator is 0.01-10wt% of the total amount of styrene, isopropyl methacrylate and glycidyl acrylate. Preferably, the precipitation solvent in S2 is one or more of hexane, n-hexane, cyclohexane, heptane, toluene, xylene, tert-methyl ether, isopropyl ether or petroleum ether, and the precipitation solvent accounts for 50-500wt% of the total mass of the reaction solution obtained in S1. Preferably, the dissolving solvent in S3 is one or more of ethyl acetate, propyl acetate, ethyl lactate, γ-butyrolactone, N-methylpyrrolidone or N,N-dimethylformamide. Preferably, the weight average molecular weight Mw of the resin product in S4 is 30,000 to 100,000, the extinction coefficient is 0.5 to 0.7, and the PDI is 1.5 to 2.5. Preferably, the catalyst in S12 is one or more of tetrabutylammonium bromide, tetrabutylammonium fluoride, triethylamine, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride or pyridine, the molar ratio of the added amount of the R structure monomer to the glycidyl acrylate in S1 is 1:1, the added amount of the catalyst is 0.001 to 3wt% of the mass of the R structure monomer, and the dissolving solvent is one or more of ethyl acetate, propyl acetate, ethyl lactate, γ-butyrolactone, N-methylpyrrolidone or N,N-dimethylformamide. Preferably, the resin is used in a bottom anti-reflective coating of a semiconductor photoresist. Beneficial effects: The present invention has the following advantages: 1. The resin obtained in the present invention is obtained by free radical polymerization of styrene, glycidyl acrylate and isopropyl methacrylate, and the process is mature and stable. The prepared resin is a polymer, and compared with other solutions that add small molecule structures, crosslinking agents, graphene, etc., it has the advantages of no small molecule precipitation and excellent solubility; 2. The present invention introduces condensed ring structures containing anthracene, fluorene, pyrene, etc. into the resin structure, which can significantly improve the extinction coefficient. At the same time, compared with directly polymerizing monomers containing anthracene, fluorene, and pyrene structures, the price is low and the cost is controllable. In addition, the introduced anthracene, fluorene, and pyrene structures are chemically linked to the resin body, which has advantages in stability. 3. After the resin prepared in the present invention is polymerized, unreacted monomers, initiators, and small molecules such as anthracene, fluorene, and pyrene in the resin can be removed by precipitation and filtration to ensure the stability of the resin structure; 4. The PDI of the resin prepared in the present invention can reach less than 2.5, the molecular weight distribution becomes narrower, and the proportion of small molecules is reduced, which further improves the sensitivity of the resin in exposure and developing solvents and can meet the performance requirements of the bottom anti-reflective coating in the semiconductor manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is the H-NMR test spectrum of the resin obtained in Example 6. DETAILED DESCRIPTION The present invention will be further described below in conjunction with embodiments, which are explanations of the present invention and are not limited to the following embodiments: Example 1 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 80°C for 2h, cool it to 20°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 4:0.1:2, the amount of azobisisobutyronitrile is 0.01wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 50wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 30 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 was 2:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthoic acid solution with a mass fraction of 30wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetrabutylammonium bromide and propyl acetate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetrabutylammonium bromide added is 0.001wt% of 1-naphthoic acid, and a 1-naphthoic acid solution with a mass fraction of 30wt% is obtained by stirring. Example 2 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 80°C for 2h, cool it to 20°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 7:1:8, the amount of azobisisobutyronitrile is 0.01wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 50wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. Add a 30wt% 1-naphthoic acid solution dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 is 2:1, react for 4 hours, cool to 25°C, add toluene to the solution, stir for 4 hours, and filter to obtain a resin product. The preparation method of the 30wt% 1-naphthoic acid solution in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetrabutylammonium bromide and propyl acetate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetrabutylammonium bromide added is 0.001wt% of the 1-naphthoic acid, and stir to obtain a 1-naphthoic acid solution with a mass fraction of 30wt%. Example 3 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 100°C for 3h, cool it to 40°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 7:0.5:8, the amount of azobisisobutyronitrile is 10wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 500wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 35 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 was 3:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthylacetic acid solution with a mass fraction of 35wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetradecyltrimethylammonium chloride and ethyl lactate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetradecyltrimethylammonium chloride added is 3wt% of 1-naphthoic acid, and a 1-naphthoacetic acid solution with a mass fraction of 35wt% is obtained by stirring. Example 4 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 100°C for 3h, cool it to 40°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 7:0.5:8, the amount of azobisisobutyronitrile is 10wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 500wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 40 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 was 3:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthylacetic acid solution with a mass fraction of 40wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12: Add 1-naphthoic acid, tetradecyltrimethylammonium chloride and ethyl lactate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetradecyltrimethylammonium chloride added is 3wt% of the 1-naphthoic acid, and a 1-naphthoacetic acid solution with a mass fraction of 40wt% is obtained after stirring. Example 5 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 90°C for 3h, cool it to 25°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 6:1:4, the amount of azobisisobutyronitrile is 8wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 50wt%; S2. The solution obtained in S1 was heated to 80°C, reacted for 10 hours, then cooled to 30°C and n-hexane was added, n-hexane accounting for 100wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 60°C to obtain a reaction solution having a mass fraction of 40 wt%; S4. A 40 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 2-naphthoacetic acid solution to the solution in S4 was 4:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthoic acid solution with a mass fraction of 40wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 2-naphthylacetic acid, tetradecyltrimethylammonium chloride and ethyl lactate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetradecyltrimethylammonium chloride added is 2wt% of the 2-naphthylacetic acid, and a 1-naphthylacetic acid solution with a mass fraction of 40wt% is obtained by stirring. Example 6 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 90°C for 3h, cool it to 25°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 6:1:4, the amount of azobisisobutyronitrile is 8wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 50wt%; S2. The solution obtained in S1 was heated to 80°C, reacted for 10 hours, then cooled to 30°C and n-hexane was added, n-hexane accounting for 100wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 60°C to obtain a reaction solution having a mass fraction of 40 wt%; S4. A 40 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 9-anthracenecarboxylic acid solution to the solution in S4 was 4:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; The method for preparing the 9-anthracenecarboxylic acid solution with a mass fraction of 40 wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 9-anthracenecarboxylic acid, tetradecyltrimethylammonium chloride and ethyl lactate in a molar ratio of 1:1 to glycidyl acrylate in S1 into the container, wherein the amount of tetradecyltrimethylammonium chloride added is 2wt% of 9-anthracenecarboxylic acid, and stir to obtain a 9-anthracenecarboxylic acid solution with a mass fraction of 40wt%. Example 7 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 90°C for 3h, cool it to 25°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 6:1:4, the amount of azobisisobutyronitrile is 8wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 50wt%; S2. The solution obtained in S1 was heated to 80°C, reacted for 10 hours, then cooled to 30°C and n-hexane was added, n-hexane accounting for 100wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 60°C to obtain a reaction solution having a mass fraction of 40 wt%; S4. A 40 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 9-fluorenecarboxylic acid solution to the solution in S4 was 4:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; The method for preparing the 9-fluorenecarboxylic acid solution with a mass fraction of 40 wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 9-fluorenecarboxylic acid, tetradecyltrimethylammonium chloride and ethyl lactate in a molar ratio of 1:1 to glycidyl acrylate in S1 into the container, wherein the amount of tetradecyltrimethylammonium chloride added is 2wt% of 9-fluorenecarboxylic acid, and a 9-fluorenecarboxylic acid solution with a mass fraction of 40wt% is obtained by stirring. Example 8 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 90°C for 3h, cool it to 25°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 6:1:4, the amount of azobisisobutyronitrile is 8wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 50wt%; S2. The solution obtained in S1 was heated to 80°C, reacted for 10 hours, then cooled to 30°C and n-hexane was added, n-hexane accounting for 100wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 60°C to obtain a reaction solution having a mass fraction of 40 wt%; S4. A 40 wt% 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 9-fluorenecarboxylic acid solution to the solution in S4 was 4:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; The method for preparing the 9-fluorenecarboxylic acid solution with a mass fraction of 40 wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 2-carboxypyrene, tetradecyltrimethylammonium chloride and ethyl lactate in a molar ratio of 1:1 to glycidyl acrylate in S1 into the container, wherein the amount of tetradecyltrimethylammonium chloride added is 2wt% of 2-carboxypyrene, and stir to obtain a 9-fluorenecarboxylic acid solution with a mass fraction of 40wt%. Comparative Example 1 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 80°C for 2h, cool it to 20°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 8:3:8, the amount of azobisisobutyronitrile is 0.01wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 50 wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 30 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 was 2:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthoic acid solution with a mass fraction of 30wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetrabutylammonium bromide and propyl acetate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetrabutylammonium bromide added is 0.001wt% of the 1-naphthoic acid, and stir to obtain a 1-naphthoic acid solution with a mass fraction of 30wt%. Comparative Example 2 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 80°C for 2h, cool it to 20°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 3:0.05:1, the amount of azobisisobutyronitrile is 0.01wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 50wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 30 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 was 2:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthoic acid solution with a mass fraction of 30wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetrabutylammonium bromide and propyl acetate in an amount equal to that of glycidyl acrylate into a container, wherein the amount of tetrabutylammonium bromide added is 0.001 wt % of 1-naphthoic acid, and stir to obtain a 1-naphthoic acid solution with a mass fraction of 30 wt %. Table 1 Effect of the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate on resin properties From the above examples and comparative examples, as the proportion of glycidyl acrylate and substituted monomer increases, the extinction coefficient gradually increases. If the proportion is too high, it is easy to cause the problem of excessive PDI; if the proportion is insufficient, it cannot provide a good extinction coefficient. Comparative Example 3 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 100°C for 3h, cool it to 40°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 7:0.5:8, the amount of azobisisobutyronitrile is 10wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 500wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 20wt% 1-naphthoic acid solution is added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 is 3:1, the reaction is continued for 4 hours, the temperature is lowered to 25°C, toluene is added to the solution, and the solution is stirred for 4 hours and then filtered to obtain a resin product; wherein the preparation method of the 20wt% 1-naphthoic acid solution in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetrabutylammonium bromide and ethyl lactate in a molar ratio of 1:1 to glycidyl acrylate in S1 into the container, wherein the amount of tetrabutylammonium bromide added is 3wt% of 1-naphthoic acid, and stir to obtain a 1-naphthoacetic acid solution with a mass fraction of 20wt%. Comparative Example 4 A method for preparing a resin for an anti-reflection coating with a high extinction coefficient, the method comprising the following steps: S1. Dry the container at 100°C for 3h, cool it to 40°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, glycidyl acrylate and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 7:0.5:8, the amount of azobisisobutyronitrile is 10wt% of styrene, isopropyl methacrylate and glycidyl acrylate, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and n-hexane was added, n-hexane accounting for 500wt% of the total mass of the reaction solution obtained in S1, stirred for 1 hour, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 was added to ethyl acetate and the temperature was raised to 55°C to obtain a reaction solution having a mass fraction of 35 wt%; S4. A 45 wt % 1-naphthoic acid solution was added dropwise to the solution obtained in S3, the volume ratio of the 1-naphthoic acid solution to the solution in S4 was 3:1, and the reaction was continued for 4 hours and then cooled to 25°C to obtain a resin product; Wherein, the preparation method of the 1-naphthylacetic acid solution with a mass fraction of 45wt% in S4 comprises the following steps: S11. Dry the container at 80°C for 2h and cool to 20°C, replacing nitrogen three times; S12. Add 1-naphthoic acid, tetrabutylammonium bromide and ethyl lactate in a molar ratio of 1:1 to the glycidyl acrylate in S1 into the container, wherein the amount of tetrabutylammonium bromide added is 3wt% of the 1-naphthoic acid, and stir to obtain a 1-naphthoacetic acid solution with a mass fraction of 45wt%. Comparative Example 5 The difference between this comparative example and Example 3 and Example 4 is that the R monomer structure is not introduced. Table 2 Effect of R structure monomer solution concentration on resin properties From the above comparative examples and embodiments, if the concentration of the R structure monomer is too low, after adding the resin solution, the system concentration decreases, resulting in insufficient reaction, which leads to a decrease in the extinction coefficient; and if the monomer concentration is too high, after adding the resin solution, the resin has a certain viscosity after polymerization, which can easily cause the added R structure monomer to be wrapped by the resin solution, thereby reducing the connected R structure and causing a decrease in the extinction coefficient. Comparative Example 6 The difference between this comparative example and Example 5, Example 6, Example 7 and Example 8 is that the acrylic acid monomer with anthracene side chain is directly polymerized, and the preparation method includes the following steps: S1. Dry the container at 100°C for 3h, cool it to 40°C and replace nitrogen three times, then add methanol, styrene, isopropyl methacrylate, 9-methacrylic acid anthracene ester and azobisisobutyronitrile, the molar ratio of styrene, isopropyl methacrylate and 9-methacrylic acid anthracene ester is 7:0.5:8, the amount of azobisisobutyronitrile is 10wt% of styrene, isopropyl methacrylate and 9-methacrylic acid anthracene ester, and stir to obtain a solution with a mass fraction of 40wt%; S2. The solution obtained in S1 was heated to 75°C, reacted for 8 hours, cooled to 20°C and added with n-hexane, wherein n-hexane accounted for 500wt% of the total mass of the solution obtained in S1. After stirring for 1 hour, the mixture was filtered and dried to obtain a resin product. Table 3 Effect of R structure monomer types on resin properties From the above examples and comparative examples, it can be seen that after replacing different R-structured monomers, excellent extinction coefficients can be provided. However, when 9-anthracene methacrylate is directly used for polymerization, since the monomer is solid, the proportion of anthracene side groups is too large, and there is a trend of decreased solubility and reactivity, thereby causing the PDI to increase to 2.7. Too large PDI is not conducive to the stability of the resin. Compared with the same proportion of Example 6 containing R-structured 9-anthracenecarboxylic acid, the extinction coefficient is lower. Note: 1. Weight average molecular weight test (Mw) and molecular weight distribution (PDI) test: Gel permeation chromatography was used for testing, the mobile phase was tetrahydrofuran solvent, and the testing instrument was Waters 2695 model machine of Waters Company; 2. Extinction coefficient test (K): In order to facilitate the uniform comparison of the extinction coefficient performance of resins with different structures, the resin coating thickness is controlled to 75nm, coated on the glass surface, baked at 150°C for 3 minutes, and tested and analyzed using a Bruker ellipsometer FilmTek6000PAR-SE instrument. Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A resin for high extinction coefficient anti-reflection coating, characterized in that: The resin has a structure shown in formula (1): Wherein, z accounts for 20-80% of the total molar ratio, y+x accounts for 1-80% of the total molar ratio, and x accounts for ≤70%; Wherein, the R structure is one or more of naphthyl, anthracenyl, fluorenyl or pyrene structures.

2. The high extinction coefficient anti-reflection coating resin according to claim 1, characterized in that: The monomer of the R structure is one or more of 1-naphthoic acid, 1-naphthoacetic acid, 2-naphthoacetic acid, 9-anthracenecarboxylic acid, 9-fluorenecarboxylic acid or 2-carboxypyrene monomers.

3. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 1, characterized in that: The preparation method comprises the following steps: S1. The container is dried at 80-100°C for 2h, cooled to 20-40°C and replaced with nitrogen three times, and then a reaction solvent, styrene, isopropyl methacrylate, glycidyl acrylate and an initiator are added, and a solution having a mass fraction of 40-90wt% is obtained by stirring; S2. The solution obtained in S1 was heated to 75-85°C, reacted for 8-12 hours, then cooled to 20-40°C and a precipitation solvent was added, stirred for 1-3 hours, filtered and dried to obtain a filter cake; S3. The filter cake obtained in S2 is added to a dissolving solvent and the temperature is raised to 55 to 65° C. to obtain a reaction solution having a mass fraction of 35 to 45 wt %; S4. Add the R structure monomer solution dropwise into the solution obtained in S3, the volume ratio of the R structure monomer solution to the solution in S4 is 2 to 5:1, react for 4 to 6 hours, then cool to 25°C to obtain a resin product.

4. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 3, characterized in that: The method for preparing the R structure monomer solution in S4 comprises the following steps: S11. The container was dried at 80-100°C for 2h and cooled to 25°C, followed by replacement of nitrogen three times; S12. Add R structure monomer, catalyst and dissolving solvent into the container, and obtain R structure monomer solution with a mass fraction of 30-40wt% by stirring.

5. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 3, characterized in that: The reaction solvent in S1 is one or more of methanol, ethanol, isopropanol, propylene glycol methyl ether acetate, propylene glycol methyl ether, N-methylpyrrolidone, N,N-dimethylformamide, 4-methyl-2-pentanone or N,N-dimethylacetamide.

6. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 3, characterized in that: The initiator in S1 is one or more of azobisisobutyronitrile, azobisisoheptylnitrile, dimethyl azobisisobutyrate, dibenzoyl peroxide, tert-butyl perbenzoate or diisopropyl peroxydicarbonate, the molar ratio of styrene, isopropyl methacrylate and glycidyl acrylate is 4-7:0.1-1:2-8, and the amount of the initiator is 0.01-10wt% of the total amount of styrene, isopropyl methacrylate and glycidyl acrylate.

7. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 3, characterized in that: The precipitation solvent in S2 is one or more of hexane, n-hexane, cyclohexane, heptane, toluene, xylene, tert-methyl ether, isopropyl ether or petroleum ether, and the precipitation solvent accounts for 50-500wt% of the total mass of the reaction solution obtained in S1.

8. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 3, characterized in that: The dissolving solvent in S3 is one or more of ethyl acetate, propyl acetate, ethyl lactate, γ-butyrolactone, N-methylpyrrolidone or N,N-dimethylformamide.

9. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 3, characterized in that: The weight average molecular weight Mw of the resin product in S4 is 30,000 to 100,000, the extinction coefficient is 0.5 to 0.7, and the PDI is 1.5 to 2.

5.

10. The method for preparing a resin for high extinction coefficient anti-reflection coating according to claim 4, characterized in that: The catalyst in S12 is one or more of tetrabutylammonium bromide, tetrabutylammonium fluoride, triethylamine, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride or pyridine, the molar ratio of the added amount of the R structure monomer to the glycidyl acrylate in S1 is 1:1, the added amount of the catalyst is 0.001-3wt% of the mass of the R structure monomer, and the dissolving solvent is one or more of ethyl acetate, propyl acetate, ethyl lactate, γ-butyrolactone, N-methylpyrrolidone or N,N-dimethylformamide.

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