Preparation method of multi-component styrene resin for photoresist
By connecting acid-sensitive groups after the photoresist synthesis process and adopting a multi-step synthesis method, the problem of high cost and difficult to control the component ratio during the synthesis process is solved, and the stability and controllable preparation of multi-component styrene resin is achieved, and the production efficiency and performance of photoresist is improved.
Patent Information
- Application Number
- CN202411980640.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-04-25
AI Technical Summary
During the synthesis process, existing polypara styrene resins face the problem that the proportion of polymer components is difficult to control during the high monomer cost and the copolymerization of multiple monomers, which limits the application range and production efficiency of photoresist.
By post-attachment of acid-sensitive groups, a multi-step synthesis method is adopted, including single monomer polymerization and post-modification, which avoids the proportion uncertainty caused by the polymerization rate of multiple monomers during the mixing process, and achieves the stability and controllability of three components and even more components of styrene resins.
The preparation controllability and production efficiency of styrene resins are improved, the cost is reduced, and the resin with narrow molecular weight distribution and stable proportions is obtained, meeting the needs of modern lithography technology.
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Figure CN119874973A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing photoresist, in particular to a method for synthesizing multi-component styrene photoresist resin. Background Art
[0002] Photoresist is a core material in semiconductor and microelectronic technology. It forms patterns on the substrate through light irradiation to assist subsequent processes. Technological advances have promoted higher requirements for photoresist performance. Polyparahydroxystyrene resin is widely used in deep ultraviolet photoresist due to its specific structure, especially chemically amplified photoresist at a wavelength of 248nm, both positive and negative. The water-based developability brought by its structure is extremely critical to modern semiconductor manufacturing and other fields. Although polyparahydroxystyrene resin has strong permeability, it has strong lipophilicity, and the photoresist film made from it is easy to crack and has insufficient adhesion. In order to improve the development solubility of photoresist and solve these problems, people continue to improve the structure of this type of resin. Studies have shown that partial protection of hydroxyl groups, such as the introduction of t-BOC groups, ketals, acetals, furans, etc., can not only have obvious solubility changes, but also improve the above film problems. In addition, narrowly distributed PHS resins exhibit better lithography performance. Anionic polymerization is widely considered to be an effective method for obtaining polymers with narrow molecular weight distribution. However, in anionic polymerization reactions, carbon-containing styrene monomers are difficult to participate in the reaction. In addition, existing poly(p-hydroxystyrene) resins face the challenges of high monomer cost and difficulty in controlling the proportion of each component of the polymer during copolymerization of multiple monomers during the synthesis process, which limits the application range and production efficiency of photoresists. Therefore, the development of a new method for preparing multi-component styrene resins can not only reduce production costs, but also obtain resin materials with stable and controllable components, which has important practical significance and application prospects. In addition, by introducing acid-sensitive groups at a later stage, styrene resin materials with three or more components can be effectively realized to meet the needs of modern photolithography technology. Summary of the invention
[0003] Technical problem to be solved: The present invention aims to provide a multi-component styrene resin for photoresist and a preparation method thereof. By post-adding acid-sensitive groups, the problems of uncertainty in the ratio of multiple monomers due to the reactivity ratio during the co-polymerization process and the inability of anionic polymerization to polymerize carbon-containing styrene monomers are avoided, thereby increasing the possibility of preparing three or more components of styrene resins.
[0004] Technical solution: A multi-component styrene resin for photoresist, the synthesis route of the resin is as follows: Wherein, the structure represented by R1 is any one of methyl, ethyl, tert-butyl, acetyl or benzyl; wherein x is the molar ratio of the unit where the hydroxyl group is located in the resin, and x ≥ 50%; Wherein, y and z are the molar ratios of the acid-sensitive groups in the resin to the units, and 1%<y+z<50%; Wherein, R2 and R3 are any two of the following groups. Preferably, the synthesis method comprises the following steps: S1. Adding monomer 1 and an initiator / organic solvent solution to an organic solvent to obtain a reaction solution having a mass fraction of 15-40 wt%, followed by a polymer polymerization reaction and adding a precipitation solvent to obtain a polymer 1; S2. dissolving polymer 1 in an organic solvent to obtain a reaction solution having a mass fraction of 15-40 wt %, heating and stirring under acidic or alkaline conditions to perform a deprotection reaction, and then adding a precipitation solvent to obtain polymer 2; S3. The polymer 2 and the catalyst are dissolved in an organic solvent to obtain a reaction solution A having a mass fraction of 15-40 wt%, the compound 1 containing the acid-sensitive group R2 is dissolved in an organic solvent to obtain a solution B, the solution B is added to the reaction solution A and stirred until the reaction is complete, and a precipitation solvent is added to obtain a polymer 3; S4. The precipitated polymer 3 is dissolved in an organic solvent to obtain a reaction solution A with a mass fraction of 15-40wt%, the compound 2 containing the acid-sensitive group R3 is dissolved in an organic solvent to obtain a solution B, the solution B is added to the reaction solution A, and after stirring until the reaction is complete, a precipitated solvent is added to obtain a multi-component styrene resin. Preferably, monomer 1 in S1 is any one of p-tert-butoxystyrene or p-acetoxystyrene, the polymer polymerization reaction time is 1-10h, the polymer polymerization reaction is free radical polymerization or anionic polymerization, the initiator / organic solvent solution of the free radical polymerization is an azo or peroxide initiator / organic solvent solution, the initiator / organic solvent solution of the anionic polymerization is a butyl lithium or alkali metal initiator / organic solvent solution, the initiator addition amount accounts for 1-10wt% of the mass of the reaction monomer, and the mass fraction of the initiator / organic solvent solution is 1-10wt%. Preferably, the compound 1 and the compound 2 are any one of trimethylsilyl chloride, di-tert-butyl dicarbonate, benzyl chloroformate, ethyl vinyl ether, or 3,4-dihydropyran, and the added amounts of the compound 1 and the compound 2 are 1-30% of 1 mole of the monomer, respectively, and the organic solvent is any one or more of dimethylformamide, toluene, tetrahydrofuran, cyclohexane, benzene, xylene, dioxane or n-heptane. Preferably, the precipitation solvent is any one or more of methanol, ethanol, petroleum ether or water, and the volume ratio of the precipitation solvent to the reaction solution is 3-15:1. Preferably, the acid used in the deprotection reaction in S2 is any one of trifluoroacetic acid, hydrochloric acid or hydrobromic acid, the base used is any one or more of sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate, the deprotection reaction temperature is 25-60°C, the reaction time is 1-6h, and the amount of the acid or base is 1-3 times the amount of 1 mole of the monomer. Preferably, the catalyst in S3 is any one or both of trifluoroacetic acid or pyridinium p-toluenesulfonate, the amount of the catalyst added is 1-20% of 1 mole of the compound, the reaction time is 1-3h, and the reaction temperature is 0-30°C. Preferably, the catalyst in S4 is any one or more of 4-dimethylaminopyridine, triethylamine or sodium hydroxide, the amount of the catalyst added is 10-100% of the molar amount of compound 2, the reaction time is 1-3h, and the temperature is 0-30°C. Preferably, the multi-component styrene resin has an average weight average molecular weight of 5000-20000 and a PDI of 1.1-1.4. Beneficial effects: Compared with the prior art, the present invention has the following characteristics: The present invention provides a method for preparing a multi-component styrene resin for photoresist. First, a single monomer is polymerized and then modified to obtain a multi-component styrene polymer that meets the ratio of KrF photoresist resin, thereby avoiding the reactivity ratio of different styrene monomer structures. In addition, since the styrene monomer containing a carbon group cannot participate in anion reaction, it is impossible to obtain a PHS resin with a narrow molecular weight distribution containing an ester group (such as a t-boc group) through anion polymerization. The method of the present invention effectively avoids this problem, so that a resin with a narrow molecular weight distribution (PDI < 1.1) and a stable ratio can be prepared through anion polymerization. In addition, the method can also obtain a resin with a narrow PDI (PDI ≤ 1.4) through free radical polymerization. The reaction process is simpler and more controllable, with better flexibility and lower process cost. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is the GPC chart of the polymer prepared in Example 1; Figure 2 is the H of the polymer prepared in Example 1 1 NMR spectra; Figure 3 This is the GPC chart of the polymer prepared in Example 2; Figure 4 is the H of the polymer prepared in Example 2 1 NMR spectra; DETAILED DESCRIPTION The present invention is further described below in conjunction with examples, which are explanations of the present invention and are not limited to the following examples. Without departing from the spirit and substance of the present application, any modification or replacement of the method, step or condition of the present application shall fall within the scope of the present application. Example 1 A method for preparing a multi-component styrene resin for photoresist, the preparation method comprising the following steps: S1. 40 g of p-acetoxystyrene (0.247 mol) was dissolved in 80 g of DMF to obtain a solution with a mass fraction of 33.3 wt %, and then the temperature was raised to 80° C. and a 3 wt % azobisisobutyronitrile / DMF initiator solution (the molar amount of azobisisobutyronitrile was 0.008 mol) was added to obtain a reaction solution. After reacting at 80° C. for 4 h, a methanol solution was added dropwise, and the volume ratio of the methanol solution to the reaction solution was 10:1 to obtain a polymer 1-1; S2. The polymer 1-1 was dissolved in 80 g THF and stirred evenly, and then the temperature was raised to 40 ° C to obtain a reaction solution. 9.8 g NaOH (0.247 mol) was dissolved in 5 g purified water and then slowly dripped into the reaction solution. After reacting at 40 ° C for 3 h, the temperature was lowered to room temperature, the pH of the reaction solution was adjusted to 5 and purified water was dripped into it. The volume ratio of purified water to the reaction solution was 8: 1, and polymer 2-1 was precipitated; S3. The polymer 2-1 and pyridinium p-toluenesulfonate (0.62 g, 2.47 mmol) were dissolved in 30 g THF reaction solution A, 1.78 g vinyl ethyl ether (0.0247 mol) was dissolved in 10 g THF to obtain solution B, solution B was added to the reaction solution A, reacted at 20 ° C for 3 h, and purified water was added dropwise for precipitation. The volume ratio of purified water to the reaction solution was 8:1 to obtain polymer 3-1; S4. The polymer 3-1 and 0.55 g 4-dimethylaminopyridine (4.94 mmol) were dissolved in 30 g THF to obtain a reaction solution A. Subsequently, 10.76 g di-tert-butyl dicarbonate (0.0494 mol) was dissolved in 10 g THF to obtain a solution B. The solution B was added to the reaction solution A. After reacting at 0°C for 2 h, purified water was added dropwise for precipitation. The volume ratio of purified water to the reaction solution was 8:1 to obtain a polymer 3-1. Example 2 A method for preparing a multi-component styrene resin for photoresist, the preparation method comprising the following steps: S1. 5 g of p-tert-butoxystyrene (0.0284 mol) was added to 20 g of THF to obtain a reaction solution with a mass fraction of 20 wt%, nitrogen was introduced and stirred at -70°C, 8.9 wt% of n-butyl lithium / DMF initiator solution (the molar amount of n-butyl lithium was 1.2 mmol) was added to the reaction solution, and after reacting at -70°C for 1 h, methanol solution was added dropwise, the volume ratio of methanol solution to reaction solution was 8:1, and polymer 1-2 was obtained by precipitation; S2. The polymer 1-2 was dissolved in 20 g of THF to obtain a reaction solution A. After the temperature was raised to 40 ° C, 7 g of trifluoroacetic acid (0.0612 mol) was dropped into the reaction solution. After the reaction was allowed to react at 40 ° C for 12 h, purified water was added dropwise. The volume ratio of the purified water reaction solution was 8:1. After precipitation, polymer 2 was obtained. S3. The polymer 2 and 0.06 g of pyridinium p-toluenesulfonate (0.284 mmol) were dissolved in 20 g of THF to obtain a reaction solution A, 0.20 g of vinyl ethyl ether (2.84 mmol) was dissolved in 5 g of THF to obtain a solution B, and the solution B was added to the reaction solution A. After reacting at 20 ° C for 3 h, purified water was added dropwise, and the volume ratio of purified water to the reaction solution was 8: 1, and polymer 3-1 was obtained by precipitation; S4. The polymer 3-1 and 0.07 g 4-dimethylaminopyridine (0.568 mmol) were dissolved in 20 g THF and stirred at 0°C to obtain a reaction solution A. 1.24 g di-tert-butyl dicarbonate (5.68 mmol) was dissolved in 10 g THF to obtain a solution B. The solution B was added to the reaction solution A. After reacting at 0°C for 2 h, purified water was added dropwise. The volume ratio of purified water to the reaction solution was 10:1. After precipitation, a multi-component styrene resin 1 was obtained. Example 3 A method for preparing a multi-component styrene resin for photoresist, the preparation method comprising the following steps: S1. 40 g of p-acetoxystyrene (0.247 mol) was dissolved in 80 g of DMF to obtain a solution with a mass fraction of 33.3 wt %, and then the temperature was raised to 80° C. and a 3 wt % azobisisobutyronitrile / DMF initiator solution (the molar amount of azobisisobutyronitrile was 0.008 mol) was added to obtain a reaction solution. After reacting at 80° C. for 4 h, a methanol solution was added dropwise, and the volume ratio of the methanol solution to the reaction solution was 12:1 to obtain a polymer 1-1; S2: polymer 1-1 was dissolved in 80 g THF and stirred evenly, then heated to 40°C, 9.8 g NaOH (0.247 mol) was dissolved in 5 g purified water and added dropwise to the reaction solution, reacted at 40°C for 3 h, then cooled to room temperature, the pH of the reaction solution was adjusted to 5, and purified water was added dropwise, the volume ratio of purified water to the reaction solution was 8:1, and polymer 2-1 was precipitated; S3. The polymer 2-1 and 0.62 g of pyridinium p-toluenesulfonate (2.47 mmol) were dissolved in 30 g of THF to obtain a reaction solution A, 1.78 g of vinyl ethyl ether (0.0247 mol) was dissolved in 10 g of THF to obtain a solution B, and the solution B was added to the reaction solution A. After reacting at 20 ° C for 3 h, the pH of the solution was adjusted to 5, and purified water was added dropwise for precipitation. The volume ratio of purified water to the reaction solution was 12:1 to obtain a polymer 3-1; S4. Dissolve polymer 3-1 and 5.0g triethylamine (0.0494mol) in 30g THF and stir at 0°C to obtain reaction solution A; dissolve 5.36g trimethylsilyl chloride (0.0494mol) in 10g THF to obtain solution B; add solution B to reaction solution A, react at 0°C for 2h, then drop purified water into the mixture; the volume ratio of purified water to reaction liquid is 10:1; and obtain multi-component styrene resin 2 after precipitation. Example 4 A method for preparing a multi-component styrene resin for photoresist, the preparation method comprising the following steps: S1. 5 g of p-tert-butoxystyrene (0.0284 mol) was added to 20 g of THF to obtain a reaction solution with a mass fraction of 20 wt%, nitrogen was introduced and stirred at -70°C, 8.9 wt% of n-butyl lithium / DMF initiator solution (the molar amount of n-butyl lithium was 1.2 mmol) was added to the reaction solution, and after reacting at -70°C for 1 h, methanol solution was added dropwise, the volume ratio of methanol solution to reaction solution was 8:1, and polymer 1-2 was obtained by precipitation; S2. The polymer 1-2 was dissolved in 20 g of THF to obtain a reaction solution, and the temperature was raised to 40 ° C. Then 7 g of trifluoroacetic acid (0.0612 mol) was dropped into the reaction solution, and the reaction was carried out at 40 ° C for 12 h. After cooling to room temperature, purified water was added dropwise, and the volume ratio of the purified water reaction solution was 8: 1, and polymer 2 was obtained by precipitation; S3. The polymer 2 and 0.06 g of pyridinium p-toluenesulfonate (0.284 mmol) were dissolved in 20 g of THF and stirred at 3 ° C to obtain a reaction solution A, 0.26 g of 3,4-dihydropyran (2.84 mmol) was dissolved in 5 g of THF to obtain a solution B, and the solution B was added to the reaction solution A at 3 ° C for 3 h, and then purified water was added dropwise, the volume ratio of purified water to the reaction solution was 8:1, and polymer 3-2 was obtained by precipitation; S4. The polymer 3-2 and 0.07 g 4-dimethylaminopyridine (0.568 mmol) were dissolved in 20 g THF and stirred at 0°C to obtain a reaction solution A. 0.97 g benzyl chloroformate (5.68 mmol) was dissolved in 2 g THF to obtain a solution B. The solution B was added to the reaction solution A and reacted at 0°C for 2 h. Purified water was then added dropwise. The volume ratio of purified water to the reaction solution was 11:1. The multi-component styrene resin 3 was obtained after precipitation. Comparative Example 1 S1. 16.41 g of monomer 4-(tert-butyldimethylsilyloxy)styrene, 4.41 g of monomer 4-tert-butyloxycarbonylstyrene and 1.92 g of 4-(ethoxyethoxy) were added to 20 g of DMF, nitrogen was introduced and stirred at room temperature, the temperature was raised to 80°C, 0.71 g of azobisisobutyronitrile was dissolved in DMF to obtain an initiator solution, and the initiator solution was slowly added dropwise to the flask. After the addition was completed, the temperature was maintained constant and the reaction was continued for 4 hours. The volume ratio of the methanol solution to the reaction solution was 8:1, and a polymer was precipitated; S2. Add 40g THF and the polymer obtained in S1 and stir evenly at room temperature. Slowly drip 70ml tetrabutylammonium fluoride solution (1M) into the reaction solution, maintain the temperature after the dripping is complete, and react for 1h. After the reaction is completed, drip into purified water for precipitation, wherein the volume ratio of purified water to reaction solution is 8:1 to obtain multi-component styrene resin 1. Table 1 Effects of different synthetic routes on multi-component styrene resins From the above experimental results, it can be concluded that the three-component styrene resin obtained by post-modification has a narrow molecular weight distribution (PDI≤1.4), and the proportion of each component is consistent with expectations, which can meet the performance requirements of 248nm photoresist for film-forming resin. Note: 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. Obviously, the above embodiments are only examples for clear description, and are not limitations on the implementation methods. For ordinary technicians in the field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the invention.
Claims
1. A multi-component styrene resin for photoresist, characterized in that: The synthetic route of the resin is as follows: Wherein, the structure represented by R1 is any one of methyl, ethyl, tert-butyl, acetyl or benzyl; wherein x is the molar ratio of the unit where the hydroxyl group is located in the resin, and x ≥ 50%; Wherein, y and z are the molar ratios of the acid-sensitive groups in the resin to the units, and 1%<y+z<50%; Wherein, R2 and R3 are any two of the following groups.
2. The method for synthesizing a multi-component styrene resin for photoresist according to claim 1, characterized in that: The synthesis method comprises the following steps: S1. Adding monomer 1 and an initiator / organic solvent solution to an organic solvent to obtain a reaction solution having a mass fraction of 15-40 wt%, followed by a polymer polymerization reaction and adding a precipitation solvent to obtain a polymer 1; S2. dissolving polymer 1 in an organic solvent to obtain a reaction solution having a mass fraction of 15-40 wt %, heating and stirring under acidic or alkaline conditions to perform a deprotection reaction, and then adding a precipitation solvent to obtain polymer 2; S3. The polymer 2 and the catalyst are dissolved in an organic solvent to obtain a reaction solution A having a mass fraction of 15-40 wt%, the compound 1 containing the acid-sensitive group R2 is dissolved in an organic solvent to obtain a solution B, the solution B is added to the reaction solution A and stirred until the reaction is complete, and a precipitation solvent is added to obtain a polymer 3; S4. The precipitated polymer 3 is dissolved in an organic solvent to obtain a reaction solution A with a mass fraction of 15-40wt%, the compound 2 containing the acid-sensitive group R3 is dissolved in an organic solvent to obtain a solution B, the solution B is added to the reaction solution A, and after stirring until the reaction is complete, a precipitated solvent is added to obtain a multi-component styrene resin.
3. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The monomer 1 in S1 is any one of p-tert-butoxystyrene or p-acetoxystyrene, the polymer polymerization reaction time is 1-10h, the polymer polymerization reaction is free radical polymerization or anionic polymerization, the initiator / organic solvent solution of the free radical polymerization is an azo or peroxide initiator / organic solvent solution, the initiator / organic solvent solution of the anionic polymerization is butyl lithium or alkali metal initiator / organic solvent solution, the added amount of the initiator accounts for 1-10wt% of the mass of the reaction monomer, and the mass fraction of the initiator / organic solvent solution is 1-10wt%.
4. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The compound 1 and the compound 2 are any one of trimethylsilyl chloride, di-tert-butyl dicarbonate, benzyl chloroformate, ethyl vinyl ether or 3,4-dihydropyran, and the addition amount of the compound 1 and the compound 2 respectively accounts for 1-30% of 1 mole of the monomer, and the organic solvent is any one or more of dimethylformamide, toluene, tetrahydrofuran, cyclohexane, benzene, xylene, dioxane or n-heptane.
5. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The precipitation solvent is any one or more of methanol, ethanol, petroleum ether or water, and the volume ratio of the precipitation solvent to the reaction solution is 3-15:
1.
6. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The acid used in the deprotection reaction in S2 is any one of trifluoroacetic acid, hydrochloric acid or hydrobromic acid, the base used is any one or more of sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate, the deprotection reaction temperature is 25-60°C, the reaction time is 1-6h, and the amount of the acid or base used is 1-3 times of 1 mole of the monomer.
7. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The catalyst in S3 is any one or both of trifluoroacetic acid and pyridinium p-toluenesulfonate, the amount of the catalyst added is 1-20% of 1 mole of the compound, the reaction time is 1-3h, and the reaction temperature is 0-30°C.
8. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The catalyst in S4 is any one or more of 4-dimethylaminopyridine, triethylamine or sodium hydroxide, the amount of the catalyst added is 10-100% of the molar amount of compound 2, the reaction time is 1-3h, and the temperature is 0-30°C.
9. The method for synthesizing a multi-component styrene resin for photoresist according to claim 2, characterized in that: The multi-component styrene resin has an average weight average molecular weight of 5000-20000 and a PDI of 1.1-1.4.