Photoacid generator, resist composition, and pattern forming method

Abstract

The application provides a photoacid generator, a resist composition and a pattern forming method, and relates to the technical field of photoetching materials. The photoacid generator has a general formula represented by structural formula (1). In structural formula (1), a is 1 or 2; X is -CO-, a dicarboxylic imide forming a five-membered ring on the left and right sides thereof, or X is -CH2CO-, a dicarboxylic imide forming a six-membered ring on the left and right sides thereof; Y and the carbon atom on the right side thereof together form a C6-C10 monocyclic saturated aliphatic hydrocarbon ring, a C6-C14 bridged ring or a C6-C14 aromatic ring. The photoacid generator can improve the LER performance of a resist film pattern and improve the developing defects of the resist film in the resist composition.

Description

Technical Field

[0001] This application relates to the field of photolithography materials technology, and in particular to a photoacid-generating agent, a photoresist composition, and a patterning method. Background Technology

[0002] Photolithography technology has advanced rapidly with the continuous development of integrated circuits. From g-line (436 nm) and i-line (365 nm) to deep ultraviolet (DUV) excimer lasers at 248 nm and 193 nm, and then to extreme ultraviolet (EUV), the wavelength of the exposure light source has gradually shortened. At the same time, this has increased the critical demand for resist compositions with higher sensitivity and resolution. Currently, the process dominated by wafer fabs uses light waves with wavelengths of 193 nm and below for photolithography (ArF lithography), which can be divided into 193 nm dry lithography and 193 nm immersion lithography.

[0003] ArF lithography, due to the small size of the images formed, advances pattern miniaturization through short-wavelength radiation such as ArF excimer lasers or immersion lithography (where exposure is performed in a liquid medium filling the space between the lens and the resist film in the exposure apparatus). The photoacid generator in the resist composition is particularly important. Since most photoacid generators are ionic compounds with poor solubility, they cannot be uniformly distributed in the resist film, causing the line edge roughness (LER) of the resist pattern to be affected by the acid diffusion distance. During the post-exposure baking (PEB) stage, excessive free acid migration and diffusion across the entire resist film further increase LER. Therefore, it is crucial to address the solubility of photoacid generators and the unpredictability of acid diffusion to reduce development defects. Summary of the Invention

[0004] This application provides a photoacid generator, a photoresist composition, and a pattern forming method. The photoacid generator in the photoresist composition can improve the LER performance of the photoresist film pattern, and at the same time improve the solubility of the photoresist composition in the developer tetramethylammonium hydroxide, thereby improving the development defects of the photoresist film.

[0005] In a first aspect, this application provides a method comprising: the photoacid-producing agent having the general formula represented by structural formula (1),

[0006] (1)

[0007] In the structural formula (1), a is 1 or 2;

[0008] R1 is a perfluorosubstituted butyl, trifluoromethyl, tridecafluorohexyl, heptadecafluorooctyl, 2,2,2-trifluoroethyl, 1,1-difluoroethyl, 1,1-difluoropropyl, 1,1,2,2-tetrafluoropropyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, norbornelalkyltetrafluoroethyl, adamantane-1,1,2,2-tetrafluoropropyl, or bicyclo[2.2.1]heptane-tetrafluoromethyl;

[0009] X is a dicarboxylidene with a -CO- ring forming a five-membered ring with both sides, or X is a dicarboxylidene with a -CH2CO- ring forming a six-membered ring with both sides;

[0010] Y, together with the carbon atom to its right, forms a C6-C10 monocyclic saturated aliphatic hydrocarbon ring, a C6-C14 bridged ring, and a C6-C14 aromatic ring.

[0011] In one possible implementation, in the structural formula (1), X is -CO-, forming a five-membered ring diformimide with both sides, and Y together with the two carbon atoms on its right side forms a C6~C8 monocyclic saturated aliphatic hydrocarbon ring or a C6~C10 bridged ring; or, X is -CH2CO-, forming a six-membered ring diformimide with both sides, and Y together with the three carbon atoms on its right side forms a C6~C10 bridged ring, a naphthalene ring, or an anthracene ring.

[0012] In one possible implementation, the photoacid-generating agent is selected from one or more of the following structures:

[0013] .

[0014] In one possible implementation, in the structural formula (1), a is 1.

[0015] In one possible implementation, the photoacid-generating agent is selected from one or more of the following structures:

[0016] .

[0017] In one possible implementation, in the structural formula (1), X is -CO-, forming a five-membered ring diformimide with both sides thereon, and Y forms a C6~C10 bridging ring with the two carbon atoms on its right side.

[0018] In one possible implementation, in the structural formula (1), R1 is a perfluorosubstituted butyl or trifluoromethyl.

[0019] In a second aspect, this application provides an anti-corrosion composition, characterized in that it comprises: a photoacid generator (A), a host resin (B), an acid diffusion control agent (C), a fluorinated resin (D), and an organic solvent (E) as described in any embodiment of the first aspect.

[0020] In one possible implementation, based on 100 parts by weight of the main resin (B), the amount of photoacid generator (A) added is 0.1 to 20 parts by weight, the amount of acid diffusion control agent (C) added is 0.1 to 5 parts by weight, and the amount of fluorinated resin (D) added is 0.1 to 30 parts by weight.

[0021] Thirdly, this application provides a method for forming a resist pattern, characterized by comprising the following steps:

[0022] S1, Coating: The photoresist composition described in any embodiment of the second aspect is applied to a substrate and cured thereon to form a photoresist film;

[0023] S2, Immersion Exposure: After drying, light of a specific wavelength is penetrated through the liquid medium, and then ArF excimer laser is used to irradiate a specific area of ​​the photoresist film to perform immersion exposure.

[0024] S3, Development: After baking, the exposed photoresist film is developed using a developing solution to obtain a photoresist pattern.

[0025] In the above technical solution, by adding a photoacid generator with a structural formula (1) to the photoresist composition, the lactam generated by the photoacid generator during the reaction process can act as an acid diffusion control agent, thereby inhibiting the diffusion of acid in the photoresist film and improving the LER performance of the photoresist film pattern. In addition, the lactam contains a carboxylic acid substituent, which improves the solubility of the photoresist composition in the developer tetramethylammonium hydroxide and improves the development defects of the photoresist film. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0027] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] It should be noted that the following embodiments are examples of this application and are used only to illustrate this application, and are not intended to limit this application. Other combinations and various modifications within the scope of this application are possible without departing from the spirit or scope of this application.

[0030] The photo-induced acid-generating agent, resist composition, and pattern formation method provided in this application are described in detail below.

[0031] The photoacid-producing agent of this application embodiment has the general formula represented by structural formula (1).

[0032] (1)

[0033] In structural formula (1), a is 1 or 2; R1 is perfluorosubstituted butyl, trifluoromethyl, tridecafluorohexyl, heptadecafluorooctyl, 2,2,2 trifluoroethyl, 1,1-difluoroethyl, 1,1-difluoropropyl, 1,1,2,2-tetrafluoropropyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, norbornel alkyltetrafluoroethyl, adamantane-1,1,2,2-tetrafluoropropyl, bicyclic [2.2.1]heptane-tetrafluoromethyl; X is -CO-, forming a five-membered ring diformimide with both sides, or X is -CH2CO-, forming a six-membered ring diformimide with both sides; Y together with the carbon atom on its right side forms a C6~C10 monocyclic saturated aliphatic hydrocarbon ring, a C6~C14 bridged ring, or a C6~14 aromatic ring.

[0034] When radiation irradiates the photoacid-producing agent with the above structure, the N−O bond of the sulfonamide ester is broken, thereby forming a diformimide compound and a sulfonic acid compound. The diformimide compound further decomposes into a lactam and CO2, and the reaction process is shown below:

[0035]

[0036]

[0037] This application introduces a photoacid-generating agent with the aforementioned structure into the resist composition, deprotonating the resist composition to release the corresponding photoacid. The resulting photoacid deprotects the main resin in the resist, thereby altering the resin's polarity and changing the solubility of the main resin in the exposed area, increasing the contrast between the exposed and unexposed areas. Simultaneously, because the lactam produced during the reaction contains carboxylic acid substituents, the resist composition exhibits high solubility in tetramethylammonium hydroxide (TMAH) as a developer, effectively improving the development defects of the resist film. Furthermore, the lactam acts as an acid diffusion control agent, inhibiting acid diffusion within the resist film and improving the LER performance of the resist film pattern.

[0038] Furthermore, in structural formula (1), X is -CO-, forming a five-membered ring diformimide with both sides, and Y together with the two carbon atoms on the right side forms a C6~C8 monocyclic saturated aliphatic hydrocarbon ring or a C6~C10 bridged ring. Alternatively, X is -CH2CO-, forming a six-membered ring diformimide with both sides, and Y together with the three carbon atoms on the right side forms a C6~C10 bridged ring, a naphthalene ring, or an anthracene ring.

[0039] Photoacid-producing agents are selected from one or more of the following structures:

[0040] .

[0041] Since structural formula (1) contains a carboxyl group, its solubility in alkaline developing solution is improved, thereby reducing insoluble components in the exposed section. However, when the carboxyl group is directly bonded to the ring, structural formula (1) will aggregate when a=2 (i.e., the photoacid generator contains 2 carboxyl groups), increasing the insoluble components after development and increasing the risk of development defects. When a=1 (i.e., the photoacid generator contains only 1 carboxyl group), due to the reduced degree of freedom, no solid will precipitate, further improving the suppression effect of development defects. To further improve the number of development defects, in structural formula (1) of this application, a=1.

[0042] Preferably, the photoacid-generating agent is selected from one or more of the following structures:

[0043] .

[0044] Furthermore, in the structural formula (1) of this application, Y forms a C6-C10 bridged ring together with the carbon atom on its right. Under deep ultraviolet (DUV, 193 nm) exposure, the photoacid-generating agent synthesized from the bridged cycloalkane skeleton of diformimide can improve the transparency of the resist film and efficiently release strong acid, thus enhancing the sensitivity of the resist composition. Simultaneously, the fused ring structure of the bridged cycloalkane can effectively limit the lateral diffusion of photoacid molecules in the resist film, thereby benefiting the LER performance of the resist film pattern. Preferably, the photoacid-generating agent is selected from one or more of the following structures:

[0045] .

[0046] Furthermore, in the structural formula (1) of this application, X is -CO-, forming a five-membered ring diformimide with both sides, and Y forms a C6~C10 bridged ring with the two carbon atoms on its right side. Since the six-membered ring is more rigid and stable than the five-membered ring, the photo-induced acid-producing agent synthesized from the five-membered ring diformimide skeleton is more likely to undergo the above-mentioned hydrolysis reaction to generate lactam under deep ultraviolet (DUV, 193 nm) exposure.

[0047] Furthermore, in the structural formula (1) of this application, R1 is a perfluorosubstituted butyl or a trifluoromethyl. Since perfluorosubstituted butyl and trifluoromethyl have strong electron-withdrawing capabilities, they can be used to... - The combination of highly electron-withdrawing perfluorinated alkyl groups in relatively close positions can further enhance acid strength, thereby further improving the sensitivity of the resist composition.

[0048] More preferably, the photoacid-generating agent is selected from one or more of the following structures:

[0049] .

[0050] This application also provides a photoresist composition comprising a photoacid generator (A), a main resin (B), an acid diffusion control agent (C), a fluorinated resin (D), and an organic solvent (E). The components are described below in sequence.

[0051] <Photo-induced acid production agent (A)>

[0052] The photoacid-generating agent (A) is as described above. Based on 100 parts by weight of the main resin (B), the amount of photoacid-generating agent (A) added is preferably 0.1 parts by weight or more, more preferably 2 parts by weight or more, and even more preferably 5 parts by weight or more. Furthermore, based on 100 parts by weight of the main resin (B), the amount of photoacid-generating agent (A) added is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, and even more preferably 5 parts by weight or less.

[0053] <Main Resin (B)>

[0054] In this application, the main resin (B) is a polyacrylate derivative, having the general formula represented by structural formula (2).

[0055] (2)

[0056] In structural formula (2), R2 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R3 is a monovalent hydrocarbon group with 1 to 8 carbon atoms, either substituted or unsubstituted; R4 and R5 are independently monovalent chain hydrocarbon groups with 1 to 8 carbon atoms or monovalent alicyclic hydrocarbon groups with 3 to 12 carbon atoms, or represent a divalent alicyclic hydrocarbon group with 3 to 12 carbon atoms formed by the combination of R4 and R5 and the carbon atoms bonded to R4 and R5.

[0057] The main resin (B) comprises repeating units (B-1), repeating units (B-2), and repeating units (B-3). Repeating unit (B-1) is an acid-sensitive repeating unit. R2 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R3 to R5 represent monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, which can be listed as the group obtained by removing one hydrogen atom from monocyclic saturated alicyclic hydrocarbons, unsaturated alicyclic hydrocarbons, or alicyclic polycyclic hydrocarbons with 3 to 20 carbon atoms. Specific examples of these alicyclic hydrocarbons include monocyclic saturated alicyclic hydrocarbons such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; and monocyclic unsaturated alicyclic hydrocarbons such as cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclodecene. Repeating unit (B-1) can be listed as follows:

[0058]

[0059] In this unit, the repeating unit (B-2) is a lactone repeating unit; it allows for easier adjustment of the solubility of the host resin (B) in the developer, improving adhesion to the substrate and achieving enhanced lithography properties such as resolution. As the repeating unit (B-2), R2 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R3-R4 are structural units comprising at least one of the following groups: cyclic lactone structure, cyclic carbonate structure, and sulfonyl lactone structure. Examples of repeating units (B-2) are as follows:

[0060]

[0061] The repeating unit (B-3) is a polar repeating unit. The repeating unit (B-3) adjusts the solubility of the main resin (B) in the developer, thereby improving the film-forming properties of the composition, such as resolution. As a polar group in the repeating unit (B-3), R2 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R3-R4 are straight-chain or cyclic alkyl hydrocarbons containing hydroxyl, carboxyl, cyano, nitro, or polar groups. Examples of repeating units (B-3) are as follows:

[0062]

[0063] In this application, the main resin (B) is a ternary or quaternary copolymer resin, comprising at least one repeating unit as described in formula (B-1). Among all the structural units constituting the main resin (B), the content of structural unit (B-1) is 10-90 mol%, more preferably 30-60 mol%; the content of at least one repeating unit as described in formula (B-2) is 5-30 mol%, more preferably 15-30 mol%; and the content of at least one repeating unit as described in formula (B-3) is 5-30 mol%, more preferably 15 mol%-30 mol%.

[0064] <Acid Diffusion Control Agent (C)>

[0065] Acid diffusion control agent (C) suppresses the diffusion of acid generated by photoacid-generating agents during exposure into the resist film, thereby inhibiting acid-induced chemical reactions in unexposed areas. By incorporating acid diffusion control agent (C) into the resist composition, the performance and photolithographic properties of the resist film can be improved, particularly enhancing the contrast of the resist film to improve resolution.

[0066] As an acid diffusion control agent (C), nitrogen-containing compounds or photodegradable bases can be listed. The photodegradable base used in this application is preferably a triarylsulfonium salt. In this application, the acid diffusion control agent (C) has the following structural formulas C1 to C3, and one or more can be used alone or in combination.

[0067]

[0068] When the resist composition contains an acid diffusion control agent (C), the amount of acid diffusion control agent (C) added is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 3 parts by weight or more, based on 100 parts by weight of the main resin (B). Furthermore, the amount of acid diffusion control agent (C) added is preferably 5 parts by weight or less, more preferably 4.5 parts by weight or less, and even more preferably 4 parts by weight or less, based on 100 parts by weight of the main resin (B). By setting the amount of acid diffusion control agent (C) within the aforementioned range, the LWR performance of the resist composition can be further improved. As the acid diffusion control agent (C), one type can be used alone, or two or more types can be used in combination.

[0069] Fluoropolymer (D)

[0070] Fluorinated resin (D) tends to be present on the surface of the resist film more than the host resin (B). Due to the low surface energy, unique molecular structure, and stable chemical properties of the CF bonds in fluorinated resin (D), it can improve the hydrophobicity of the resist film surface during water immersion exposure. Fluorinated resin (D) has the general formula represented by structural formula (3).

[0071] (3)

[0072] Wherein, R2 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Z is an alkyl group with 1 to 10 carbon atoms, and R7 is a perfluoroalkyl group with 1 to 10 carbon atoms. Preferably, Z is 1 to 2, and R7 is 1 to 2 carbon atoms. Fluoropolymers (D) can be listed as follows:

[0073] (D-1)

[0074] When the resist composition contains a fluorinated resin (D), the amount of fluorinated resin (D) added is preferably 0.1 parts by weight or more, more preferably 2 parts by weight or more, and even more preferably 5 parts by weight or more, based on 100 parts by weight of the main resin (B). Furthermore, the amount of fluorinated resin (D) added is preferably 30 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the main resin (B).

[0075] <Organic Solvents (E)>

[0076] The organic solvent (E) is any solvent capable of dissolving or dispersing the components in the resist composition, and is not particularly limited. Examples of organic solvents (E) include alcohols, ethers, ketones, esters, etc.

[0077] Examples of alcohols include 4-methyl-2-pentanol, n-hexanol, and 1,2-propanediol. Examples of ethers include propylene glycol monomethyl ether (PGME), diisopentyl ether, tetrahydrofuran, and tetrahydropyran. Examples of ketone solvents include cyclohexanone and methyl-2-n-pentyl ketone. Examples of ester solvents include propylene glycol monomethyl ether acetate (PGMEA), n-butyl acetate, ethyl lactate (EL), and γ-butyrolactone.

[0078] Preferred ingredients include one or more of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl lactate (EL), and γ-butyrolactone.

[0079] <Pattern Formation Methods>

[0080] This application also provides a pattern forming method, comprising: a step of coating a resist composition onto one surface of a substrate (hereinafter also referred to as a "coating step"); a step of exposing the resist film obtained by the coating step (hereinafter also referred to as an "exposure step"); and a step of developing the exposed resist film (hereinafter also referred to as a "development step").

[0081] Coating process

[0082] The resist composition is typically coated onto a substrate using conventional equipment such as a spin coater. The resist composition is preferably filtered using a filter with a pore size of 0.2 μm before coating. Examples of substrates include silicon wafers or quartz wafers on which sensors, circuits, transistors, etc., are to be formed. After coating, a soft bake (SB) is performed to allow the solvent in the coating to evaporate. The SB temperature is preferably 60 °C or higher, more preferably 80 °C or higher. Furthermore, the SB temperature is preferably 140 °C or lower, more preferably 120 °C or lower. The SB time is preferably 5 seconds or higher, more preferably 10 seconds or higher. Furthermore, the SB time is preferably 600 seconds or lower, more preferably 300 seconds or lower. The average thickness of the formed resist film is preferably 100 nm to 1000 nm, more preferably 100 nm to 500 nm.

[0083] Exposure process

[0084] The resulting composite layer is typically exposed using a dry exposure apparatus or a liquid immersion exposure apparatus. Exposure is generally performed using a mask corresponding to the desired pattern. Various types of exposure light sources can be used, such as ultraviolet lasers like KrF stimulated excimer lasers (wavelength: 248 nm), ArF stimulated excimer lasers (wavelength: 193 nm), F2 stimulated excimer lasers (wavelength: 157 nm), and immersion ArF-i stimulated excimer lasers (wavelength: 134 nm). Alternatively, the exposure apparatus can be an electron beam exposure apparatus or an extreme ultraviolet (EUV) exposure apparatus. Post-exposure baking (PEB) is performed on the exposed portion of the resist film, utilizing the acid generated by the photoacid after exposure to promote the dissociation of acid-sensitive groups, thereby improving sensitivity. The temperature and time of PEB directly affect the diffusion range and reaction rate of the photoacid, thus affecting the critical dimension (CD), sidewall angle, and line edge roughness (LER) of the developed pattern.

[0085] The resist composition of the present invention is preferably exposed using an ArF immersion exposure apparatus. The PEB temperature is preferably 50 °C or higher, more preferably 80 °C or higher. Furthermore, the PEB temperature is preferably 180 °C or lower, more preferably 130 °C or lower. The PEB time is preferably 5 seconds or higher, more preferably 10 seconds or higher. Furthermore, the PEB time is preferably 600 seconds or lower, more preferably 300 seconds or lower.

[0086] Development process

[0087] After heat treatment, the resist film is developed, typically using an alkaline developing solution. Development here refers to contacting the resist film with an alkaline solution after heat treatment. This dissolves and removes the exposed portions of the resist film using the alkaline solution, leaving the unexposed portions of the composite layer on the substrate, thereby creating a resist pattern. An aqueous solution comprising tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (common name: choline) can be used as the alkaline developing solution. Tetramethylammonium hydroxide developing solution is preferred. After development, the film is generally rinsed with a washing solution such as water and then dried.

[0088] The technical solution of the present invention will be further described below with reference to specific embodiments. The abbreviations corresponding to some compounds involved in the embodiments will be explained below.

[0089] Monomer T-1:

[0090] Monomer T-2:

[0091] Monolithic T-3:

[0092] T-4 monolithic:

[0093] T-5 single unit:

[0094] AIBN: Azobisisobutyronitrile

[0095] Acid diffusion control agent C1:

[0096] Acid diffusion control agent C2:

[0097] Organic solvent E1: Propylene glycol monomethyl ether acetate (PGMEA)

[0098] Organic solvent E2: Propylene glycol monomethyl ether (PGME)

[0099] Organic solvent E3: Ethyl lactate (EL)

[0100] Photoacid-producing agent A12:

[0101] Photoacid-producing agent A13:

[0102] Photoacid-producing agent A14:

[0103] Synthesis Example 1 (Synthesis of Main Resin B1)

[0104] Monomers (T-1), (T-2), and (T-4) were dissolved in 200 parts by mass of 2-butanone in a molar ratio of 40 / 40 / 20 (mol%). AIBN was added as an initiator (5 mol% relative to the total 100 mol% of the monomers used) to prepare a monomer solution. 100 parts by mass of 2-butanone was added to a reaction vessel, and after purging with nitrogen for 30 minutes, the reaction vessel was set to 80°C. The monomer solution was added dropwise over 3 hours while stirring. The start of the dropwise addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was water-cooled to below 30°C. The cooled polymerization solution was added to methanol (2000 parts by mass), and the precipitated white powder was filtered and separated. The filtered white powder was washed twice with methanol, filtered again, and dried at 50°C for 24 hours to obtain a white powdery resin (B1) (yield: 85%). The main resin (B1) has a Mw of 7100 and an Mw / Mn ratio of 1.61.

[0105] Synthesis Example 2 (Synthesis of Main Resin B2)

[0106] Monomers (T-2), (T-3), and (T-4) were dissolved in 200 parts by mass of 2-butanone in a molar ratio of 35 / 45 / 20 (mol%). AIBN was added as an initiator (5 mol% relative to the total 100 mol% of the monomers used) to prepare a monomer solution. 100 parts by mass of 2-butanone was added to a reaction vessel, and after purging with nitrogen for 30 minutes, the reaction vessel was set to 80°C. The monomer solution was added dropwise over 3 hours while stirring. The start of the dropwise addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was water-cooled to below 30°C. The cooled polymerization solution was added to methanol (2000 parts by mass), and the precipitated white powder was filtered and separated. The filtered white powder was washed twice with methanol, filtered again, and dried at 50°C for 24 hours to obtain a white powdery resin (B2) (yield: 85%). The main resin (B2) has a Mw of 9100 and an Mw / Mn ratio of 1.65.

[0107] Synthesis Example 3 (Synthesis of Fluorine-containing Resin D1)

[0108] The monomer (T-5) was dissolved in 200 parts by mass of 2-butanone, and AIBN was added as an initiator. Simultaneously, nitrogen gas was blown into the solution for about 10 minutes, and the reaction was carried out with stirring at 80°C for 6 hours. After cooling to room temperature, the solution was concentrated under reduced pressure, and then injected into methanol (2000 parts by mass) to precipitate the resin, which was then filtered. The resin was dried at 40°C for 24 hours to obtain a white solid, D1 (yield: 85%). The Mw of the fluorinated resin (D1) was 8100, and the Mw / Mn ratio was 1.55.

[0109] Synthesis Example 4 (Synthesis of Fluorine-containing Resin D2)

[0110] Monomers (T-5) and (T-1) were dissolved in 200 parts by mass of 2-butanone, and AIBN was added as an initiator. Simultaneously, nitrogen gas was blown into the solution for about 10 minutes, and the reaction was carried out with stirring at 80°C for 6 hours. After cooling to room temperature, the solution was concentrated under reduced pressure, and then injected into methanol (2000 parts by mass) to precipitate the resin, which was then filtered. The resin was dried at 40°C for 24 hours to obtain a white solid, D2 (yield: 85%). The Mw of the fluorinated resin (D2) was 7500, and the Mw / Mn ratio was 1.62.

[0111] Synthesis Example 5 (Synthesis of photoacid-producing agent A1)

[0112] Under a nitrogen atmosphere, 21.6 g (100 mmol) of tricarboxylic acid compound (I-1), 11 mL (110 mmol) of anhydrous acetic anhydride, and 200 mL of solvent 1,4-dioxane were added, and the mixture was refluxed at 160 °C for 4 h. All solvent was evaporated under reduced pressure, and 10 times the mass of toluene was added to the residue. The mixture was allowed to stand for 4 h to allow crystals to precipitate, and then dried to give product I-2. 15 g (75.6 mmol) of compound (I-2) was mixed with 150 mL of pyridine, and 5.26 g (75.6 mmol) of hydroxylamine hydrochloride was added. The mixture was heated at 80 °C for 15 h. The reaction mixture was poured into 50 mL of 1N HCl. The precipitate was filtered, washed with water, and purified by column chromatography (20% ethyl acetate / petroleum ether) to give compound I-3. At 0 °C, 11.86 g (70.36 mmol) of trifluoromethanesulfonyl chloride was added dropwise to a mixture of 9.49 g (93.81 mmol) of triethylamine, 10 g (46.91 mmol) of compound (I-3), and 100 mL of ultradry DCM. The mixture was then stirred overnight at room temperature. After the reaction was complete, it was quenched with cold water, diluted with DCM, the organic layer was separated, dried over Na2SO4, and the solvent was removed under vacuum to give an orange crude sulfonate, which was purified by column chromatography (20% ethyl acetate / hexane) to give photoacid-producing agent A1 as an orange solid in 60% yield.

[0113]

[0114] I-1 I-2 I-3 A1

[0115] Synthesis Example 6 (Synthesis of photoacid-producing agent A2)

[0116] At 0 °C, 22.41 g (70.36 mmol) of perfluorobutyl sulfonyl chloride was added dropwise to a mixture of 9.49 g (93.81 mmol) of triethylamine, 10 g (46.91 mmol) of compound (I-3), and 100 mL of ultradry DCM. The mixture was then stirred overnight at room temperature. After the reaction was complete, it was quenched with cold water, diluted with DCM, the organic layer was separated, dried over Na2SO4, and the solvent was removed under vacuum to give an orange crude sulfonate, which was purified by column chromatography (20% ethyl acetate / hexane) to give photoacid-producing agent A2 in 60% yield.

[0117]

[0118] I-3 A2

[0119] Synthesis Examples 7~15

[0120] Photoacid generators A3 to A11 were synthesized following the routes of Synthesis Examples 5 and 6 above, with the only difference being the different starting materials for (I-1) compound and sulfonyl chloride compound. Their structures are shown in Table 1.

[0121] Table 1. Structural formulas of photoacid-producing agents A3~A11

[0122]

[0123] Example 1

[0124] This embodiment provides a photoresist composition, which is prepared by mixing 100 parts by weight of a main resin (B1), 10.0 parts by weight of a photoacid generator (A1), 5.0 parts by weight of an acid diffusion control agent (C2), 1.0 part by weight of a fluorinated resin (D1) (solid component), and 3000 parts by weight of a mixed solvent (E1) / (E2) / (E3) as an organic solvent (2500 / 400 / 100 (parts by weight)). The mixture is then filtered using a membrane filter with a pore size of 0.2 μm.

[0125] Examples 2-13 & Comparative Examples 1-4

[0126] Examples 2-13 and Comparative Examples 1-4 each provide an anti-corrosion composition. The preparation method is roughly the same as that in Example 1, except that the types of photo-induced acid-generating agent, main resin, acid diffusion control agent, and fluorinated resin are different. The specific formulations are shown in Table 2.

[0127] Table 2 Formulations of the resist compositions in Examples 1-13 and Comparative Examples 1-4

[0128]

[0129] <Pattern Formation (ArF Immersion Exposure)>

[0130] Using a spin coater (Tokyo Electron's "CLEAN TRACKACT12"), a lower layer film forming composition (Brewer Science's "ARC66") was applied onto a 12-inch silicon wafer, followed by heating at 205°C for 60 seconds to form a lower layer film with an average thickness of 100 nm. Using the same spin coater, an ArF immersion photoresist composition prepared as described was applied onto this lower layer film and pre-baked at 100°C for 60 seconds (PB). Subsequently, it was cooled at 23°C for 30 seconds to form a photoresist film with an average thickness of 90 nm. Next, using an ArF excimer laser immersion exposure apparatus (ASML's "TWINSCAN XT-1900i"), with NA = 1.35 and σ = 0.9 / 0... Under optical conditions of 0.7, a mask with 50 nm lines and 100 nm spacing on the wafer was exposed. After exposure, it was baked at 100°C for 60 seconds (PEB). Subsequently, the resist film was alkaline developed using a 2.38 wt% TMAH aqueous solution as an alkaline developer. After development, the film was rinsed with water and then dried, thereby forming a positive resist pattern (50 nm lines and spatial pattern).

[0131] The sensitivity, LER, and number of development defects were tested according to the following evaluation method.

[0132] (1) Sensitivity test

[0133] The exposure value used to form the 50nm line and spatial pattern is set as the optimal exposure value, and this optimal exposure value is set as the sensitivity (mJ / cm). 2 Sensitivity is at 25 mJ / cm. 2 The following conditions indicate good sensitivity, exceeding 25 mJ / cm². 2 The situation indicates poor sensitivity.

[0134] (2) LER test

[0135] For the measurement of the resist pattern, a scanning electron microscope (SEM) was used (Hitachi High-Technologies). The line width of the 1:1 line-spaced pattern at 50 nm was measured under an SEM to determine the line width variation (30 points were measured, and the 3σ value was calculated), denoted as LER. The smaller the LER value, the smaller the fluctuation of the line pattern and the better the outline.

[0136] (3) Number of development defects

[0137] A 50nm linewidth line and space pattern is formed by exposing the resist film at the optimal exposure level, and this wafer is used for defect inspection. The number of defects on this wafer is determined using a KLA2810 defect inspection device (KLA-Tencor). Defects with a diameter of 50μm or less are considered to originate from the resist film, and their number is calculated. A defect count of 50 or fewer after development is considered good, while a count exceeding 50 is considered poor.

[0138] For resist patterns formed using ArF immersion photoresist compositions, sensitivity, LWR performance, and number of development defects were evaluated according to the method described above. The results are shown in Table 3 below.

[0139] Table 3 Evaluation results of the resist compositions of Examples 1-13 and Comparative Examples 1-4

[0140]

[0141] Table 3 shows the evaluation results of the photoresist compositions of Examples 1-13 and Comparative Examples 1-4. Examples 1-4 show that this photoacid-generating agent can be used in combination with different host resins, acid diffusion control agents, and fluorinated resins. Comparing Examples 1 and 5-7 shows that when R1 is perfluorinated substituted butyl or trifluoromethyl, the photoresist composition exhibits higher sensitivity. Comparing Examples 1, 5, and 8-9 shows that when X is -CO- and forms a five-membered ring with diformimide on both sides, Y forms a bridging ring with the two carbon atoms on its right side. Compared to forming a monocyclic saturated aliphatic hydrocarbon ring, the photoresist film pattern exhibits better LER performance and fewer development defects.

[0142] Comparative Examples 8-10 show that when Y forms a C6-C10 bridging ring with the carbon atom on its right, and X is a diformimide with -CO- forming a five-membered ring on both sides, the resist film exhibits fewer development defects compared to when X is a diformimide with -CH2CO- forming a six-membered ring on both sides. Comparative Examples 10-12 show that when X is a diformimide with -CH2CO- forming a six-membered ring on both sides, and Y forms a bridging ring with the three carbon atoms on its right, the resist composition exhibits better sensitivity compared to when an aromatic ring is formed.

[0143] Comparing Examples 12-13 and Comparative Example 1, it is evident that when the number of carboxylic acid groups in the photoacid generator is 2 or there are no carboxylic acid groups, the solubility of the resist composition is poor, resulting in a higher number of development defects. Comparing Examples 12-13 and Comparative Example 2, it is evident that if the carboxyl groups are replaced with ester groups, the sensitivity of the resist composition is poor, and the LER performance and development defects of the resist film pattern are also poor. Comparative Examples 3-4 show that when an ionic photoacid generator is used, the sensitivity of the resist composition is poor, and the LER performance and development defects of the resist film pattern are also poor. In this application, Examples 8-10 are preferred, exhibiting good sensitivity of the resist composition, good LER performance of the resist film pattern, and good development defects.

[0144] Although the embodiments of this application have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this application. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this application is not limited to the specific details and embodiments shown and described herein.

Claims

1. A photo-induced acid-producing agent, characterized in that, include: The photo-induced acid-producing agent has the general formula represented by structural formula (1). In the structural formula (1), a is 1 or 2; R1 is perfluorosubstituted butyl, trifluoromethyl, tridecylfluorohexyl, heptadecafluorooctyl, 2,2,2-trifluoroethyl, 1,1-difluoroethyl, 1,1-difluoropropyl, 1,1,2,2-tetrafluoropropyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, norbornel-alkyltetrafluoroethyl, adamantane-1,1,2,2-tetrafluoropropyl; X is -CO-, forming a five-membered ring dicarboximide with both sides, and Y together with the two carbon atoms on its right side forms a C6-C8 monocyclic saturated aliphatic hydrocarbon ring or a C6-C10 bridged ring. Alternatively, X is -CH2CO-, forming a six-membered ring dicarboximide with both sides, and Y together with the three carbon atoms on its right side forms a C6-C10 bridged ring.

2. The photoacid-generating agent according to claim 1, characterized in that, In the structural formula (1), a is 1.

3. The photoacid-generating agent according to claim 2, characterized in that, The photo-induced acid-producing agent is selected from one or more of the following structures:

4. The photoacid-generating agent according to claim 1 or 2, characterized in that, In the structural formula (1), X is -CO-, forming a five-membered ring diformimide with both sides, and Y forms a C6-C10 bridging ring with the two carbon atoms on its right side.

5. The photoacid-generating agent according to claim 1 or 2, characterized in that, In the structural formula (1), R1 is perfluorosubstituted butyl or trifluoromethyl.

6. A corrosion resist composition, characterized in that, include: The photoacid-generating agent, main resin, acid diffusion control agent, fluorinated resin, and organic solvent as described in any one of claims 1 to 5.

7. The resist composition according to claim 6, characterized in that, Based on 100 parts by weight of the main resin, the amount of photoacid generator added is 0.1 to 20 parts by weight, the amount of acid diffusion control agent added is 0.1 to 5 parts by weight, and the amount of fluorinated resin added is 0.1 to 30 parts by weight.

8. A method for forming a resist pattern, characterized in that, Includes the following steps: S1, Coating: The photoresist composition according to any one of claims 6 to 7 is applied to a substrate and cured to form a photoresist film; S2, Immersion Exposure: After drying, light of a specific wavelength is penetrated through the liquid medium, and then ArF excimer laser is used to irradiate a specific area of ​​the photoresist film to perform immersion exposure. S3, Development: After baking, the exposed photoresist film is developed using a developing solution to obtain a photoresist pattern.

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