Aryl sulfonate photoacid generator as well as preparation method and application thereof

Abstract

The invention discloses an aryl sulfonate photoacid generator and a preparation method and application thereof, and belongs to the technical field of photoacid generators, the photoacid generator has a structure as shown in a formula 1, and the preparation method comprises the following steps: S1, reacting a compound as shown in a formula 4 with a compound as shown in a formula 5 under the action of a catalyst 1 to generate a compound as shown in a formula 6; s2, reacting the compound as shown in the formula 6 with a compound as shown in a formula 7 under the action of a catalyst 2 to generate a compound as shown in a formula 1; the invention not only provides a non-ionic photoacid generator with excellent performance and novel structure, but also provides a brand new solution for solving the common problem of materials in the advanced photoetching technology through systematic innovation from a molecular skeleton to a functional group; and the method has important significance for improving the independent innovation capability of high-end photoetching materials in China.

Description

Technical Field

[0001] This invention belongs to the field of photoacid generator technology, and particularly relates to an aryl sulfonate photoacid generator, its preparation method and application. Background Technology

[0002] In semiconductor photolithography, chemically amplified photoresist is a key material driving the continuous miniaturization of integrated circuits, its function being to form fine patterns. The core working principle of this technology is that under specific wavelengths of light, the photoacid generator in the photoresist releases a strong acid. This acid can efficiently catalyze a chain reaction in the resin polymer during subsequent baking processes, causing deprotection or cross-linking reactions, thereby converting the weak initial light signal into significant chemical pattern changes. Therefore, the photosensitivity, acid generation efficiency, acid diffusion control capability, and compatibility with other components of the photoacid generator directly determine the final resolution, line edge roughness, and process tolerance of the lithographic pattern.

[0003] Currently, based on their chemical structures, photoacid generators can be mainly divided into two categories: ionic and non-ionic. Ionic photoacid generators, especially sulfonium salts represented by triarylsulfonates and diaryliodoses, are the mainstream category in existing technologies and dominate in high-end photoresists such as ArF, KrF, and EUV. These photoacid generators have advantages such as high acid strength, good thermal stability, and high acid generation efficiency. However, due to their ionic characteristics, phase separation or uneven dispersion may occur in the photoresist film, thus affecting the uniformity of acid generation and pattern quality.

[0004] In contrast, nonionic photoacid generators, such as sulfonates and sulfonamides, typically possess better optical transparency, lower metal impurity content, and more flexible molecular design space due to the absence of ion pairs in their molecular structure. They have become an important direction in the development of high-performance photoresists. Their structural design flexibility allows for precise control of the compound's light absorption wavelength and reactivity through systematic modification of chromophores and substituents. For example, constructing a "donor-π conjugated-acceptor" structure can effectively improve photon absorption and conversion efficiency. For instance, the sulfonic acid derivative compound disclosed in Chinese patent application CN107810179A improves the sensitivity of longer-wavelength photolithography processes by enhancing light absorption and acid generation efficiency in the 300nm–450nm wavelength range (i-line and g-line). However, based on the structural characteristics of aromatic fused-ring chromophores, these compounds may face challenges in terms of solubility, compatibility, and optical transparency at 193 nm in photoresist resins when facing advanced processes with shorter wavelengths (such as ArF 193 nm). This presents new directions and challenges for developing novel aryl sulfonate structures suitable for a wider range of photolithography windows.

[0005] Furthermore, for nonionic photoacid generators, a key ongoing challenge in this field is how to achieve high photosensitivity (especially extending to shorter wavelengths) while ensuring good solubility and compatibility in photoresist resins, and effectively controlling the diffusion behavior of photoacids through molecular structure design. Therefore, designing and preparing novel aryl sulfonate photoacid generators that achieve high photosensitivity, good resin compatibility, and controllable acid diffusion behavior has become a crucial technical issue driving the development of chemically amplified photoresist technology. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical shortcomings of existing aryl sulfonate photoacid generators in that it is difficult to synergistically optimize the light absorption wavelength, resin compatibility and acid diffusion control. This invention provides a novel aryl sulfonate photoacid generator based on a specific conjugated chromophore. Through its unique molecular structure design, this photoacid generator aims to simultaneously achieve efficient light absorption and acid generation, good compatibility in photoresist resins and controllable acid diffusion behavior, thereby improving the overall performance of photoresists in advanced processes.

[0007] The technical solution adopted in this invention is an aryl sulfonate photoacid generator, the key being that the above-mentioned photoacid generator has the structure shown in Formula 1: Formula 1, In Formula 1, R1 and R2 are independently selected from hydrogen, alkyl with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl with 2 to 10 substituted or unsubstituted carbon atoms, aryl with 6 to 12 substituted or unsubstituted carbon atoms, -NR5R6, -OR5, and -OSO2R7. R5 and R6 are independently selected from hydrogen, -CH3, -C2H5, -C3H7, and -C4H9; R7 is selected from alkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl groups with 2 to 10 substituted or unsubstituted carbon atoms, aryl groups with 6 to 12 substituted or unsubstituted carbon atoms, -NR5R6, and -OR5.

[0008] Furthermore, the above-mentioned photoacid generator has the structure shown in Formula 2: Equation 2, In Formula 2, R3 is selected from alkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl groups with 2 to 10 substituted or unsubstituted carbon atoms, and aryl groups with 6 to 12 substituted or unsubstituted carbon atoms.

[0009] Furthermore, the above-mentioned photoacid generator has the structure shown in Formula 3: Formula 3, In Formula 3, R4 is selected from alkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl groups with 2 to 10 substituted or unsubstituted carbon atoms, aryl groups with 6 to 12 substituted or unsubstituted carbon atoms, -NR5R6, -OR5, and -OSO2R7.

[0010] Specifically, the aforementioned photoacid generator has any one of the following structures: , , , , , , , , .

[0011] A method for preparing a photoacid generator compound as shown in Formula 1, the key feature of which is that it includes the following steps: S1, the compound shown in Formula 4 and the compound shown in Formula 5 react under the action of catalyst 1 to produce the compound shown in Formula 6; S2, the compound shown in Formula 6 and the compound shown in Formula 7 react under the action of catalyst 2 to produce the compound shown in Formula 1; Catalyst 1 and Catalyst 2 are independently selected from at least one of aliphatic amines, aromatic amines, ammonium fluoride, alkyl ammonium fluoride, pyridine, imidazole, piperidine, tetrahydropyrrole, DBU, DMAP, alkali metal hydroxides, and alkali metal salts of alcohols; Equation 4, Equation 5, Formula 6, Formula 7.

[0012] Specifically, in S1, the molar ratio of the compound shown in Formula 4, the compound shown in Formula 5, and catalyst 1 is 1:(0.6~2):(2~5); the reaction temperature of the above reaction in S1 is -10℃~10℃, and the reaction time is 1h~3h.

[0013] Specifically, in S2, the molar ratio of the compound shown in Formula 6, the compound shown in Formula 7, and catalyst 2 is 1:(0.8~1.5):(0.3~0.8); the reaction temperature of the above reaction in S2 is -10℃~10℃; the reaction time is 2h~5h.

[0014] Preferably, the aforementioned aliphatic amine includes at least one of methylamine, ethylamine, triethylamine, and diisopropylethylamine; the aforementioned aromatic amine includes at least one of aniline, toluidine, 4-chloro-o-toluidine, 3,3-dichlorobenzidine, and naphthylamine; and the aforementioned alkyl ammonium fluoride includes at least one of tetrabutylammonium fluoride, dodecyltrimethylammonium fluoride, tetradecyltrimethylammonium fluoride, and hexadecyltrimethylammonium fluoride.

[0015] Ideally, catalyst 1 is an alkali metal salt of an alcohol; catalyst 2 is an alkali metal hydroxide.

[0016] A photoresist, the key feature of which is that it contains the above-described photoacid generator or the photoacid generator prepared according to the above-described preparation method.

[0017] Compared with the prior art, the present invention has the following advantages: First, this invention creatively designs and synthesizes a series of novel nonionic aryl sulfonate photoacid generators. The unique framework designed in this invention is formed by efficiently constructing a phenylacetonitrile unit with a specific nitrogen-containing heterocycle (such as 2-nitrothiophene), creating a structurally stable and electronically tunable functional core. This fundamental molecular structural innovation breaks through the structural paradigm of traditional ionic (such as sulfonium salts and iodonium salts) or simple aryl ester photoacid generators, opening a new path for the design of nonionic high-performance photoacid generators.

[0018] Secondly, the photoacid generator provided by this invention, with its unique nonionic properties and finely tunable molecular structure, comprehensively solves the key contradictions in high-end photoresist materials. Its nonionic nature ensures excellent compatibility with various photoresist resins, fundamentally avoiding phase separation problems. Furthermore, by introducing diverse substituents into the core framework, the diffusion length, acid generation efficiency, and dissolution behavior of the photoacid can be synergistically optimized without affecting compatibility. This achieves an excellent balance between high photosensitivity, controllable acid diffusion, and good process adaptability, meeting the stringent requirements of advanced processes for pattern precision and process windows.

[0019] Third, the synthesis method of this invention has high versatility and scalability. The developed two-step synthetic route uses readily available raw materials, operates under mild conditions, and exhibits good functional group tolerance, enabling the efficient and high-purity preparation of a series of structurally diverse target products. This provides a powerful and flexible chemical platform for customized molecular design and rapid screening for specific exposure light sources (such as i-line, KrF, ArF) or specific resin systems.

[0020] In summary, this invention not only provides a class of high-performance, novel nonionic photoacid generators, but also offers a completely new solution to the common problems faced by materials in advanced lithography technology through systematic innovation from the molecular skeleton to functional groups. This is of great significance for enhancing my country's independent innovation capability in high-end lithography materials. Attached Figure Description

[0021] Figure 1 This is the high-performance liquid chromatogram of sample 1 of the product of this invention.

[0022] Figure 2 This is the 1H NMR spectrum of sample 1 of the product of this invention.

[0023] Figure 3 This is a high-performance liquid chromatography-mass spectrometry (HPLC-MS) spectrum of sample 1 of the present invention. Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0025] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0026] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0027] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0028] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0029] Unless otherwise specified in the examples, the procedures can be followed according to conventional conditions; unless the manufacturers of the reagents or instruments used are specified, they are all conventional products that can be purchased commercially.

[0030] In various embodiments of the present invention, aryl sulfonate photoacid generators with different structures are prepared using different starting materials.

[0031] Example 1 In this embodiment, an aryl sulfonate photoacid generator, PAG1, with the following structure was prepared. .

[0032] The specific process of this embodiment is as follows: S1. Preparation of intermediate A: The synthetic route for this step is as follows: The specific process for this step is as follows: Catalyst 1 and 500 mL of tetrahydrofuran were added to a three-necked flask, mixed and cooled; wherein, catalyst 1 is an ethanol solution with a sodium ethoxide concentration of 3.5 mol / L and a volume of 1000 mL. Add 1.5 mol of phenylacetonitrile to the system; The system temperature was controlled at 2℃, and a 2-nitrothiophene tetrahydrofuran solution with a concentration of 2 mol / L was added dropwise at a uniform rate over 90 min, with a volume of 500 mL. The reaction temperature was maintained at 0℃, and the reaction was stirred for 1.5 h.

[0033] After the reaction is complete, the reaction solution is poured into ice water and acidified with concentrated hydrochloric acid to a pH of 1.8.

[0034] Separate the organic phase, extract the aqueous phase three times with tetrahydrofuran, and combine the organic phases; add activated carbon to the organic phase and stir the organic phase; After filtering out the activated carbon and washing it with tetrahydrofuran, the filtrate was washed with water. The organic phase was dried with sodium sulfate, concentrated, and then recrystallized with tetrahydrofuran to obtain the solid product, intermediate A, denoted as intermediate A-1.

[0035] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process for this step is as follows: Add 1100 mL of 2-methyltetrahydrofuran to the reaction flask and cool to 0 °C.

[0036] Add 1 mol of intermediate A and 1.1 mol of benzenesulfonyl chloride, then add 0.5 mol of triethylamine, and keep the reaction at the specified temperature for 3.5 h; Filter and concentrate the reaction solution, add methyl tert-butyl ether, wash twice with water, extract the aqueous phase once with methyl tert-butyl ether, combine the organic phases, dry with anhydrous sodium sulfate, concentrate, and obtain crude product. The crude product was dissolved in toluene and recrystallized twice. Each recrystallization required filtration and drying. Metal impurities were then adsorbed using iminodiacetic acid-type silica gel resin. The product was then pulped again with methyl tert-butyl ether, filtered, and dried to obtain high-purity photoacid generator PAG1, which was designated as product sample 1.

[0037] Example 2 In this embodiment, an aryl sulfonate photoacid generator PAG1 with the following structure was prepared.

[0038] The specific process of this embodiment is as follows: S1. Preparation of intermediate A: The synthesis route for this step is the same as in Example 1.

[0039] The specific process of this step is the same as in Example 1, except that: an ethanol solution of 2.5 mol / L sodium ethoxide with a volume of 800 mL is used as catalyst 1; the amount of phenylacetonitrile is adjusted to 2 mol; the reaction temperature is controlled at 10 °C and the reaction time is 1 h; the subsequent process is the same as in Example 1, and a solid product, namely intermediate A, is prepared, denoted as intermediate A-2, which is used in process S2.

[0040] S2. Preparation of aryl sulfonate photoacid generators: The synthesis route for this step is the same as in Example 1.

[0041] The specific process of this step is the same as in Example 1, except that: 0.3 mol of triethylamine is used as catalyst 2; the amount of benzenesulfonyl chloride is adjusted to 0.8 mol; the reaction temperature is controlled at 10°C and the reaction time is 2 h; the subsequent process is the same as in Example 1, and a high-purity photoacid generator PAG1 is prepared, which is denoted as product sample 2.

[0042] Example 3 In this embodiment, an aryl sulfonate photoacid generator product PAG1 with the following structure was prepared, which is the same as in Example 1.

[0043] The specific process of this embodiment is as follows: S1. Preparation of intermediate A: The synthesis route for this step is the same as in Example 1.

[0044] The specific process of this step is the same as in Example 1, except that: 1250 mL of 4.0 mol / L sodium ethoxide ethanol solution is used as catalyst 1; the amount of phenylacetonitrile is adjusted to 0.6 mol; the reaction temperature is controlled at -10℃ and the reaction time is 3 h; the subsequent process is the same as in Example 1, and a solid product, namely intermediate A, is prepared, denoted as intermediate A-3, which is used in process S2.

[0045] S2. Preparation of aryl sulfonate photoacid generators: The synthesis route for this step is the same as in Example 1.

[0046] The specific process of this step is the same as in Example 1, except that: 0.8 mol of triethylamine is used as catalyst 2; the amount of benzenesulfonyl chloride is adjusted to 0.5 mol; the reaction temperature is controlled at -10℃ and the reaction time is 5 h; the subsequent process is the same as in Example 1, and a high-purity photoacid generator PAG1 is prepared, which is designated as product sample 3.

[0047] Example 4 In this embodiment, an aryl sulfonate photoacid generator, PAG2, with the following structure was prepared. .

[0048] The specific process of this embodiment is as follows: S1. Preparation of intermediate B: The synthetic route for this step is as follows: The specific process for this step is as follows: Catalyst 1 and 650 mL of toluene were added to a three-necked flask, mixed and cooled; wherein, catalyst 1 is an ethanol solution with a sodium ethoxide concentration of 3.35 mol / L and a volume of 1250 mL. Add 1.5 mol of 2-methylphenacetonitrile to the system; The system temperature was controlled at 0℃, and a toluene solution with a concentration of 2 mol / L of 2-nitrothiophene was added dropwise over 70 min, with a volume of 500 mL. Maintain the reaction temperature at 0℃, stir and react for 2 hours; After the reaction is complete, add ice water and acidify with concentrated hydrochloric acid to a pH of 2.2; Separate the organic phase, extract the aqueous phase twice with xylene, combine the organic phases, add activated carbon to the organic phase and stir; After filtering out the activated carbon and washing it with xylene, the filtrate was washed with water. The organic phase was dried with sodium sulfate, concentrated, and then recrystallized with xylene to obtain the solid product, intermediate B, denoted as intermediate B-1.

[0049] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process for this step is as follows: Add 1200 mL of tetrahydrofuran to the reaction flask and cool to 5 °C.

[0050] Add 1 mol of intermediate B and 1.2 mol of p-toluenesulfonyl chloride, then add 0.6 mol of diisopropylethylamine, and keep the reaction at the specified temperature for 4 h. The reaction solution was filtered and concentrated, then hexane was added, and the mixture was washed three times with water. The aqueous phase was extracted twice with hexane. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to obtain the crude product.

[0051] The crude product was dissolved in ethyl acetate and recrystallized twice. Each recrystallization required filtration and drying. Then, metal impurities were adsorbed using ion exchange resin. The product was then pulped again with ethyl acetate, filtered, and dried to obtain a high-purity product, namely the high-purity photoacid generator PAG2, which is designated as product sample 4.

[0052] Example 5 In this embodiment, an aryl sulfonate photoacid generator PAG1 with the following structure was prepared.

[0053] The specific process of this embodiment is as follows: S1. Preparation of intermediate B: The synthesis route for this step is the same as in Example 4.

[0054] The specific process of this step is the same as in Example 4, except that: 3.5 mol of imidazole is used as catalyst 1; the reaction temperature is controlled at 5°C and the reaction time is 2.5 h; the subsequent process is the same as in Example 4, and a solid product, namely intermediate B, is prepared, denoted as intermediate B-2, which is used in process S2.

[0055] S2. Preparation of aryl sulfonate photoacid generators: The synthesis route for this step is the same as in Example 4.

[0056] The specific process of this step is the same as in Example 4, except that: 0.6 mol of toluidine is used as catalyst 2; the reaction temperature is controlled at 5°C and the reaction time is 2.5 h; the subsequent process is the same as in Example 4, and a high-purity photoacid generator PAG2 is prepared, which is designated as product sample 5.

[0057] Example 6 In this embodiment, an aryl sulfonate photoacid generator PAG1 with the following structure was prepared.

[0058] The specific process of this embodiment is as follows: S1. Preparation of intermediate B: The synthesis route for this step is the same as in Example 4.

[0059] The specific process of this step is the same as in Example 4, except that: 3.5 mol of dodecyltrimethylammonium fluoride is used as catalyst 1; the reaction temperature is controlled at 10°C and the reaction time is 2 h; the subsequent process is the same as in Example 4, and a solid product, namely intermediate B, is prepared, denoted as intermediate B-3, which is used in process S2.

[0060] S2. Preparation of aryl sulfonate photoacid generators: The synthesis route for this step is the same as in Example 4.

[0061] The specific process of this step is the same as in Example 4, except that: 0.6 mol of tetrahydropyrrole is used as catalyst 2; the reaction temperature is controlled at 5°C and the reaction time is 3.5 h; the subsequent process is the same as in Example 1, and a high-purity photoacid generator PAG2 is prepared, which is designated as product sample 6.

[0062] Example 7 In this embodiment, an aryl sulfonate photoacid generator, PAG3, with the following structure was prepared. .

[0063] The specific process of this embodiment is as follows: S0. Preparation of sulfonyl chloride raw material A: The synthetic route for this step is as follows: The specific process for this step is as follows: 800g of 2-methyltetrahydrofuran and 500g of water were mixed to obtain a mixed solution, and 2mol of p-toluenesulfonyl chloride and 2.2mol of sodium bisulfite were added. The reaction temperature was controlled at 15℃. 200 mL of saturated sodium carbonate was added dropwise to the system. After the addition was completed, the reaction was carried out for 2 hours. Add 1400 mL of 1,2-dichloroethane to the system. A large amount of crystals will precipitate. Slurry the crystals, filter and collect them. Add the crystals to 400 mL of 1,2-dichloroethane and slurry again. Filter and collect the crystals. After vacuum drying, collect and store for later use. The above product was added to a reaction flask, and under the protection of an inert gas, 5 mol of phosphorus pentachloride was added. The reaction temperature was controlled at 60°C, and 400 mL of N-methylpyrrolidone was added dropwise. After the addition was completed, the reaction was continued at room temperature for 4 h. After the reaction is complete, quench the reaction solution with ice water; Extracted with 1,2-dichloroethane, the 1,2-dichloroethane phase was collected, washed with water to remove residual N-methylpyrrolidone, and the collected 1,2-dichloroethane phase was dried and then evaporated to obtain sulfonyl chloride raw material A.

[0064] S1. Preparation of intermediate B The synthesis route and specific process of this step are the same as S1 in Example 4, resulting in intermediate B-1.

[0065] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process for this step is as follows: Add 1200 mL of 2-methyltetrahydrofuran to the reaction flask and cool to 2 °C.

[0066] Add 1 mol of intermediate B and 1.1 mol of sulfonyl chloride raw material A, add 0.5 mol of potassium carbonate, stir and keep warm for 3.5 h; The reaction solution was filtered and concentrated, petroleum ether was added, and the mixture was washed twice with water. The aqueous phase was extracted once with petroleum ether, the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to obtain the crude product.

[0067] The crude product was dissolved in dichloromethane, separated by silica gel column chromatography, pulped with methyl tert-butyl ether, filtered, and dried. Metal impurities were removed by ion exchange resin, and the product was pulped with methyl tert-butyl ether again, filtered, and dried to obtain high-purity photoacid generator PAG3, which is designated as product sample 7.

[0068] Example 8 In this embodiment, an aryl sulfonate photoacid generator, PAG4, with the following structure was prepared. .

[0069] The specific process of this embodiment is as follows: S0. Preparation of sulfonyl chloride raw material B: The synthetic route for this step is as follows: The specific process for this step is as follows: Mix 800g of tetrahydrofuran and 500g of water to obtain a mixed solution, then add 2mol of p-toluenesulfonyl chloride and 2mol of sodium p-hydroxybenzenesulfonate. Controlling the reaction temperature at 10℃, 170 mL of an aqueous solution containing 11.6 mol / L sodium hydroxide was added dropwise to the system, and the reaction was allowed to proceed for 0.5 h after the addition was complete. Add 1400 mL of dichloromethane to the system. A large amount of crystals will precipitate. Slurry the crystals, filter and collect them. Add the crystals to 400 mL of dichloromethane and slurry again. Filter and collect the crystals. After vacuum drying, collect and store for later use. The above product was added to a reaction flask, and 12 mol of thionyl chloride was added dropwise under inert gas protection. The reaction temperature was controlled at 35°C, and 400 mL of N,N-dimethylformamide was added dropwise. After the addition was completed, the reaction was continued at room temperature for 4 h. After the reaction is complete, quench the reaction solution with ice water; Extraction was performed using dichloromethane, and the dichloromethane phase was collected. The dichloromethane phase was washed with water to remove residual N,N-dimethylformamide. The dichloromethane phase was collected, dried, and then evaporated to obtain sulfonyl chloride raw material B.

[0070] S1. Preparation of intermediate B: The synthesis route and specific process of this step are the same as in Example 4, and intermediate B-1 is prepared for use in process S2.

[0071] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process for this step is as follows: Add 1250 mL of tetrahydrofuran to the reaction flask and cool to -5 °C; Add 1 mol of intermediate B and 1.08 mol of sulfonyl chloride raw material B, add 0.54 mol of catalyst 2, which is sodium carbonate; add 50 mL of water dropwise, and keep the reaction at the temperature for 2 h; The reaction solution was filtered and concentrated, ethyl acetate was added, and the mixture was washed three times with water. The aqueous phase was extracted once with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to obtain the crude product. The crude product was dissolved in dichloromethane, separated by silica gel column chromatography, pulped with methyl tert-butyl ether, filtered, and dried. Metal impurities were removed by ion exchange resin, and the product was pulped with methyl tert-butyl ether again, filtered, and dried to obtain high-purity photoacid generator PAG4, which is designated as product sample 8.

[0072] Example 9 In this embodiment, an aryl sulfonate photoacid generator, PAG5, with the following structure was prepared. The specific process of this embodiment is as follows: S0, Preparation of sulfonyl chloride raw material C: The synthetic route for this step is as follows: The specific steps in this example are the same as S0 in Example 8, except that: an equal amount of benzenesulfonyl chloride is used to replace p-toluenesulfonyl chloride to prepare sulfonyl chloride raw material C.

[0073] S1. Preparation of intermediate B: The synthesis route and specific process of this step are the same as S1 in Example 4, resulting in intermediate B-1, which is used in process S2.

[0074] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific preparation process in this step is the same as step S2 in Example 8, except that: an equal amount of sulfonyl chloride raw material C is used to replace sulfonyl chloride raw material B; an equal amount of piperidine is used to replace sodium carbonate as catalyst 2; the reaction temperature is controlled at 0°C and the reaction time is 2.5 h; the subsequent process is the same as in Example 8, and a high-purity photoacid generator PAG5 is prepared, which is designated as product sample 9.

[0075] Example 10 In this embodiment, an aryl sulfonate photoacid generator, PAG6, with the following structure was prepared. The specific process of this embodiment is as follows: S0, Preparation of sulfonyl chloride raw material D: The synthetic route for this step is as follows: The specific process for this step is as follows: Add 1000 mL of tetrahydrofuran and 2.2 mol of triethylamine to a three-necked flask, stir under nitrogen protection and cool to -2 °C; Slowly add 2.0 mol of p-hydroxybenzenesulfonyl chloride to the system, control the system temperature at 2℃, and add 2.1 mol of methanesulfonyl chloride dropwise over 60 min; After the addition is complete, maintain the reaction temperature at 2°C and stir for 1 hour, then allow it to rise naturally to room temperature and continue the reaction for 3 hours. After the reaction is complete, it is quenched in ice water; Extraction was performed using dichloromethane, and the organic phases were combined. The organic phases were then washed once each with dilute hydrochloric acid, saturated sodium bicarbonate aqueous solution, and saturated saline solution. The organic phases were combined, dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to dryness to obtain a pale yellow oily crude product. The crude product was pulped with methyl tert-butyl ether, filtered, and the solid was washed with methyl tert-butyl ether and dried to prepare sulfonyl chloride raw material D.

[0076] S1. Preparation of intermediate C: The synthetic route for this step is as follows: The specific process for this step is as follows: The specific preparation process in this step is the same as step S1 in Example 4, except that 3-methylphenylacetonitrile is used in place of 2-methylphenylacetonitrile in an equal amount to prepare intermediate C.

[0077] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific preparation process in this step is the same as step S2 in Example 8, except that: intermediate C is used in place of intermediate B in equal amounts, and sulfonyl chloride raw material D is used in place of sulfonyl chloride raw material B in equal amounts; pyridine is used in place of sodium carbonate as catalyst 2 in equal amounts; the reaction temperature is controlled at -10℃ and the reaction time is 3h; the subsequent process is the same as in Example 8, and high-purity photoacid generator PAG6 is prepared, which is designated as product sample 10.

[0078] Example 11 In this embodiment, an aryl sulfonate photoacid generator, PAG7, with the following structure was prepared. S0. Preparation of sulfonyl chloride raw material B: The synthesis route and specific preparation process in this step are the same as step S0 in Example 8, and sulfonyl chloride raw material B is prepared.

[0079] S1. Preparation of intermediate D: The synthetic route for this step is as follows: The specific preparation process in this step is the same as step S1 in Example 4, except that: 2-vinylphenylacetonitrile is used instead of 2-methylphenylacetonitrile in an equal amount; catalyst 1 is replaced with tetrahydropyrrole, which is used in solid form and the amount is 3.5 mol; the reaction temperature is controlled at 0°C and the reaction time remains unchanged to prepare intermediate D.

[0080] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process of this step is the same as step S2 in Example 8, except that: intermediate D is used in place of intermediate B in an equal amount; sodium carbonate is used in place of catalyst 2 in an equal amount of DMAP; the reaction temperature is kept constant and the reaction time is 2.5 h; the subsequent process is the same as in Example 8, and high-purity photoacid generator PAG7 is prepared, which is denoted as product sample 11.

[0081] Example 12 In this embodiment, an aryl sulfonate photoacid generator, PAG8, with the following structure was prepared. S0. Preparation of sulfonyl chloride raw material B: The synthesis route and specific preparation process in this step are the same as step S0 in Example 8, and sulfonyl chloride raw material B is prepared.

[0082] S1. Preparation of intermediate E: The synthetic route for this step is as follows: The specific process of this step is the same as step S1 in Example 4, except that: 2-biphenylacetonitrile is used instead of 2-vinylphenylacetonitrile in an equal amount; catalyst 1 is replaced with tetradecyltrimethylammonium fluoride, which is used in solid form and the amount is 3.5 mol; the reaction temperature is controlled at 10°C and the reaction time is 4 h to prepare intermediate E.

[0083] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process of this step is the same as step S2 in Example 8, except that: intermediate E is used in place of intermediate B in an equal amount; diisopropylethylamine is used in place of sodium carbonate as catalyst 2 in an equal amount; the reaction temperature is controlled at 10°C and the reaction time is 5 hours to prepare high-purity photoacid generator PAG8, which is denoted as product sample 12.

[0084] Example 13 In this embodiment, an aryl sulfonate photoacid generator, PAG9, with the following structure was prepared. S0, Preparation of sulfonyl chloride raw material E: The synthetic route for this step is as follows: The specific steps in this example are the same as step S0 in Example 8, except that an equal amount of 4-methylsulfonylbenzenesulfonyl chloride is used to replace p-toluenesulfonyl chloride to prepare sulfonyl chloride raw material E.

[0085] S1. Preparation of intermediate B: The synthesis route and specific preparation process in this step are the same as step S1 in Example 4, and intermediate B-1 is prepared for use in S2.

[0086] S2. Preparation of aryl sulfonate photoacid generators: The synthetic route for this step is as follows: The specific process of this step is the same as step S2 in Example 8, except that: an equal amount of sulfonyl chloride raw material E is used to replace sulfonyl chloride raw material B; an equal amount of triethylamine is used to replace sodium carbonate as catalyst 2; the reaction temperature is controlled at -10℃ and the reaction time remains unchanged, and a high-purity photoacid generator PAG9 is prepared, which is recorded as product sample 13.

[0087] Analysis and Testing The purity of the products prepared in each embodiment was analyzed using high-performance liquid chromatography (HPLC). The moisture content of the final product was determined by rotary evaporation under vacuum at room temperature. The results are shown in Table 1. The test chromatogram for product sample 8 (PAG4) is shown in [Table 1]. Figure 1 .

[0088] In addition, the product sample structures were confirmed using nuclear magnetic resonance (NMR) and high-performance liquid chromatography-mass spectrometry (HPLC-MS), demonstrating that the structures of the final products obtained from each test conformed to the target structural characteristics. The test spectrum of product sample 8 (PAG4) is shown below. Figure 2 and 3 .

[0089] Table 1: Summary Table of Product Sample Quality Inspection Results As shown in Table 1, this invention successfully designed and synthesized a series of novel aryl sulfonate photoacid generators (9 in total, PAG1 to PAG9), and developed efficient and universal preparation methods for them. The preparation methods of this invention exhibit excellent versatility and reliability, stably producing ultra-high purity products with a purity of up to 99.8% and a moisture content strictly controlled below 28 ppm, fully meeting the stringent standards for core raw materials in advanced photolithography processes.

[0090] Specifically, this invention proposes a novel molecular structure, using phenylacetonitrile and its derivatives as key starting materials, to systematically construct a series of novel nonionic photoacid generators. The PAG1–PAG3 series prepared from phenylacetonitrile as a starting material, through optimized synthesis and purification processes, achieves a purity of 99.7% and a moisture content as low as 13 ppm, demonstrating the maturity and stability of the synthetic route of this invention. More importantly, this invention also exhibits strong structural adaptability: for derivatives such as 2-methylphenylacetonitrile and 3-methylphenylacetonitrile (corresponding to PAG4–PAG6), even with steric hindrance introduced onto their benzene rings or combined with complex sulfonyl chlorides containing strong electron-withdrawing groups, excellent results of 99.8% purity and only 10 ppm moisture content can still be obtained. Furthermore, for more challenging nitrile starting materials containing sensitive vinyl groups or sterically hindered biphenyl groups (corresponding to PAG7–PAG9), through targeted catalyst and condition adaptation, the product purity can still be stably maintained above 99.7%, and the moisture content controlled at extremely low levels. This fully demonstrates the broad applicability of this synthetic method to diverse precursor structures.

[0091] In summary, this invention not only provides a series of novel photoacid generators with potentially superior performance, but more importantly, it offers a universal method for the precise and stable preparation of such ultra-high purity compounds. The extremely low impurity and moisture content of all products ensures the thermal and storage stability necessary for their use as electronic chemicals, laying a solid material foundation for the subsequent development of high-performance photoresists.

[0092] Performance testing and analysis To verify the practical application potential of the aryl sulfonate photoacid generators (PAG1-PAG9) of the present invention, and to systematically evaluate their performance in terms of good resin compatibility, high photosensitivity and controllable acid diffusion behavior, representative product samples 1, 4, 7, 8, 9, 10, 11, 12, and 13 were selected as test samples; at the same time, commercially available triphenylsulfonate perfluorobutylsulfonate was selected as a commercially available reference standard for systematic evaluation.

[0093] (a) Resin compatibility test To quantitatively assess the compatibility of the product of this invention with standard photoresist resin, a turbidity measurement method was used for testing.

[0094] Accurately weigh the sample to be tested, phenolic resin, polyvinyl cinnamate (PVCN), and polyhydroxystyrene resin (PHS), and mix them at a mass ratio of 1:9. Dissolve this mixture in sufficient propylene glycol methyl ether acetate to prepare a clear solution with a solid content of 10% (mass ratio). Incubate the solution at 25°C for 24 hours to simulate storage conditions. Subsequently, measure the turbidity of the solution at a wavelength of 550 nm using a turbidimeter. The lower the turbidity value, the more uniform the dispersion of the sample and resin in the solution, the better the compatibility, and the lower the tendency for phase separation or aggregation. The test results are shown in Table 2.

[0095] Table 2: Results of Resin Compatibility Test As shown in Table 2, the compatibility of the series of aryl sulfonate photoacid generators (PAG1-PAG9) prepared in this invention with three commonly used photoresist resins is significantly better than that of commercially available ionic reference standards. This is mainly due to their nonionic molecular nature, which fundamentally avoids phase separation caused by strong electrostatic interactions. Specifically, when comparing PAG1 to PAG9, their compatibility depends primarily on the fine control of polarity and steric hindrance by the substituents in the molecule. Among them, PAG4 (product sample 8) performed the best, with the lowest turbidity value among the three resins. This is due to the synergistic effect of its R1 (ortho-methyl) and R2 (phenylsulfonyl linker containing an electron-donating methyl group), which achieved the best balance between reducing molecular polarity and optimizing spatial matching. In contrast, PAG8 (product sample 12) had the worst compatibility. Its high turbidity value mainly stemmed from the huge steric hindrance brought by the biphenyl group in R1, which severely hindered its dispersion in the resin.

[0096] The compatibility of the remaining products falls somewhere in between. PAG1 and PAG2, with their relatively simple R2 groups, and PAG5 and PAG9, with their complex R2 structures but optimized polarity, all exhibit excellent and similar compatibility. However, PAG3, PAG6, and PAG7 show slightly decreased compatibility, either due to the large size of their R2 groups or due to steric hindrance and increased polarity of their substituents. It is evident that the nonionic molecular platform of this invention possesses good tunability; by altering the R1 and R2 structures, directional optimization of other photolithographic properties can be achieved while maintaining high compatibility.

[0097] (ii) Acid diffusion length test The measurement was performed using a tracer-suppression layer dual-film method. A phenolic resin film without any photoacid generator was prepared on a silicon wafer as a suppression layer; a tracer layer containing 1.5% by mass of the test product or a commercially available reference standard was spin-coated on top of the suppression layer.

[0098] The sample or reference standard was locally exposed using an i-line light source and baked at 110°C for 90 seconds. During baking, the acid generated in the tracer layer diffused to the lower layers. Utilizing the catalytic hydrolysis of specific ester bonds by the acid, the treated sample was placed in a dilute alkaline aqueous solution to dissolve the inhibition layer region modified by acid diffusion. Finally, the step height of the dissolved region was measured using a profilometer, and the acid diffusion length was calculated using a model to visually quantify the lateral diffusion distance of the acid under specified baking conditions. The results are shown in Table 3.

[0099] (III) Acid Yield Test The acid production efficiency was quantitatively determined by ultraviolet-visible spectrophotometry using the color change reaction of an acid-sensitive dye. The test product or reference standard was dissolved together with the acid-sensitive dye rhodamine B lactone in propylene glycol methyl ether acetate, and polyvinyl butyral resin was added to form a film. The solution was then uniformly coated onto a quartz plate to form an optically uniform thin film.

[0100] Stepped exposure was performed using an i-line light source, followed immediately by measuring the change in absorbance of the film at the dye's characteristic absorption wavelength (550 nm) using a UV-Vis spectrophotometer. The absorbance change was converted into the molar concentration of acid produced per unit volume using a standard curve, and the quantum yield of acid production for the test sample or reference standard at a specific exposure level was calculated. The results are shown in Table 3.

[0101] (iv) Photosensitivity and contrast test Each product sample and reference standard was used as a photoacid generator and added to a standard chemically amplified photoresist system. The photoresist system formulation was as follows (by mass): 20% polyvinyl cinnamate, 10% photoacid generator, 0.2% surfactant, 0.2% toughening agent, and 100% made up with cyclohexanone solvent.

[0102] The prepared photoresist was coated onto a substrate and dried at 120°C for 90 seconds to form a film with a thickness of 0.20 μm. The resulting film was exposed using an excimer laser stepper (lens aperture number: 0.78) and then heat-treated at 110°C for 90 seconds. Subsequently, the film was developed with a 2.38% (w / w) tetramethylammonium hydroxide aqueous solution for 40 seconds, washed, and dried. This formed a resist pattern.

[0103] The sensitivity and contrast of the photoresist were determined using the i-line light source stepped exposure method. By measuring the remaining thickness of the resist film under different exposure energies, exposure characteristic curves were plotted. The minimum exposure energy required to completely clear the film thickness was defined as the sensitivity (D0), and the slope of the linear region of the characteristic curve was defined as the contrast (γ). The test results are shown in Table 3.

[0104] Table 3: Performance Test Results of Product Samples or Reference Standards As shown in Table 3, the series of photoacid generators provided by this invention exhibit significant advantages in both photosensitivity and image contrast. The acid diffusion length of all samples from this invention is significantly lower than that of the commercially available ionic reference standard, while the contrast is significantly higher. This indicates that the nonionic skeleton of the present invention, based on aryl sulfonate esters and its specific substituent design, can more effectively suppress the lateral diffusion of photoacids, thereby resulting in a greater contrast in chemical changes between the exposed and unexposed areas, producing images with sharper edges, and significantly improving image resolution and fidelity.

[0105] In-depth analysis of the data in Table 3 reveals that the core performance characteristics are synergistically regulated by the R1 and R2 groups. PAG4 (product sample 8) achieves the best overall balance, with its shortest acid diffusion length and highest contrast, which can be attributed to the optimal balance between the synergistic effect of its ortho-methyl group (R1) and the phenylsulfonyl linker arm (R2) containing an electron-donating methyl group. This combination allows the molecule to maintain appropriate polarity to preserve good photosensitivity while achieving the most efficient localization of the generated acid through optimized spatial conformation and intermolecular interactions. In contrast, although PAG8 (product sample 12) possesses the same excellent R2 group as PAG4, the large steric hindrance of its R1 biphenyl group severely hinders the photoreaction process, resulting in the lowest quantum yield, the worst sensitivity, and therefore the weakest overall performance.

[0106] The performance of other products demonstrates the synergistic effect of different R1 / R2 combinations. For example, PAG2 and PAG5, which share the same excellent R1 (ortho-methyl) but have slightly different R2, exhibit performance close to that of PAG4, demonstrating superior performance. PAG7, building upon the excellent R2 of PAG4, shows an increase in acid diffusion length and altered performance due to the change of R1 to a more polar vinyl group. PAG9, with the introduction of a strongly electron-withdrawing methyl sulfone group on R2, improves diffusion suppression while slightly sacrificing sensitivity. These patterns collectively demonstrate that by scientifically designing R1 and R2 groups, the behavior of photoacid generators can be systematically controlled, thereby meeting the specific resolution and sensitivity requirements of different photolithography scenarios.

[0107] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An aryl sulfonate photoacid generator, characterized in that, The photoacid generator has the structure shown in Formula 1: Formula 1, In Formula 1, R1 and R2 are independently selected from hydrogen, alkyl with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl with 2 to 10 substituted or unsubstituted carbon atoms, aryl with 6 to 12 substituted or unsubstituted carbon atoms, -NR5R6, -OR5, and -OSO2R7. R5 and R6 are independently selected from hydrogen, -CH3, -C2H5, -C3H7, and -C4H9; R7 is selected from alkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl groups with 2 to 10 substituted or unsubstituted carbon atoms, aryl groups with 6 to 12 substituted or unsubstituted carbon atoms, -NR5R6, and -OR5.

2. The photoacid generator according to claim 1, characterized in that, The photoacid generator has the structure shown in Formula 2: Equation 2, In Formula 2, R3 is selected from alkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl groups with 2 to 10 substituted or unsubstituted carbon atoms, and aryl groups with 6 to 12 substituted or unsubstituted carbon atoms.

3. The photoacid generator according to claim 2, characterized in that, The photoacid generator has the structure shown in Formula 3: Formula 3, In Formula 3, R4 is selected from alkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, alkenyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkynyl groups with 2 to 10 substituted or unsubstituted carbon atoms, aryl groups with 6 to 12 substituted or unsubstituted carbon atoms, -NR5R6, -OR5, and -OSO2R7.

4. The photoacid generator according to claim 3, characterized in that, The photoacid generator has any one of the following structures: , , ， ， ， ， ， ， 。 5. A method for preparing a photoacid-generating compound as shown in Formula 1, characterized in that, Includes the following steps: S1, the compound shown in Formula 4 and the compound shown in Formula 5 react under the action of catalyst 1 to produce the compound shown in Formula 6; S2, the compound shown in Formula 6 and the compound shown in Formula 7 react under the action of catalyst 2 to produce the compound shown in Formula 1; Catalyst 1 and Catalyst 2 are independently selected from at least one of aliphatic amines, aromatic amines, ammonium fluoride, alkyl ammonium fluoride, pyridine, imidazole, piperidine, tetrahydropyrrole, DBU, DMAP, alkali metal hydroxides, and alkali metal salts of alcohols; Equation 4, Equation 5, Formula 6, Formula 7.

6. The preparation method according to claim 5, characterized in that, In S1, the molar ratio of the compound shown in Formula 4, the compound shown in Formula 5, and catalyst 1 is 1:(0.6~2):(2~5); the reaction temperature of the reaction described in S1 is -10℃~10℃, and the reaction time is 1h~3h.

7. The preparation method according to claim 5, characterized in that, In S2, the molar ratio of the compound shown in Formula 6, the compound shown in Formula 7, and catalyst 2 is 1:(0.8~1.5):(0.3~0.8); the reaction temperature of the reaction described in S2 is -10℃~10℃; the reaction time is 2h~5h.

8. The preparation method according to claim 5, characterized in that, The aliphatic amine includes at least one of methylamine, ethylamine, triethylamine, and diisopropylethylamine; the aromatic amine includes at least one of aniline, toluidine, 4-chloro-o-toluidine, 3,3-dichlorobenzidine, and naphthylamine; the alkyl ammonium fluoride includes at least one of tetrabutylammonium fluoride, dodecyltrimethylammonium fluoride, tetradecyltrimethylammonium fluoride, and hexadecyltrimethylammonium fluoride.

9. The preparation method according to claim 5, characterized in that, Catalyst 1 is an alkali metal salt of an alcohol; catalyst 2 is an alkali metal hydroxide.

10. A photoresist, characterized in that, The photoacid generator comprises any one of claims 1-4 or a photoacid generator prepared by the preparation method according to any one of claims 5-9.

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