A photoacid generator, a method for preparing the same, and a photoresist composition containing the same

Abstract

The present invention relates to a photo-acid generator having a structure represented by formula (I) and a preparation method thereof and a photoresist composition containing the same. It can be used together with a strong-acidic sulfonium salt photo-acid generator, thereby improving resolution and contrast of a photo-lithographic pattern.

Description

Technical Field

[0001] This application belongs to the field of photoresist technology, specifically relating to a photoacid generator, its preparation method, and a photoresist composition containing the photoacid generator. Background Technology

[0002] Photoacid generators are a crucial component of chemically amplified photoresists. They generate acid through photochemical excitation, which then diffuses within the photoresist system and undergoes an acid-catalyzed reaction. This process leads to the decomposition of protecting groups on the photoresist resin, ultimately generating carboxylic acids. Subsequently, the carboxylic acid is neutralized into an organic salt by an alkaline developer and dissolved in an aqueous solution, thus forming the pattern. Throughout the process, the photoacid generator retains its original function while improving the quality and readability of the photoresist.

[0003] In existing technologies, photoacid generators, due to their small anion volume, exhibit rapid diffusion of photoacid within the photoresist system. This can lead to several problems: First, rapidly diffusing anions result in edge roughness (LER) and irregular morphologies, potentially causing photoresist residue and peeling. Second, these rapidly diffusing anions quickly penetrate unexposed areas of the photoresist, causing partial decomposition and affecting the accuracy of the lithographic pattern shape. Rapidly diffusing anions can also cause excessively fast photoresist reactions, leading to uneven photoresist decomposition and hindering pattern formation. Furthermore, rapidly diffusing anions are susceptible to environmental factors such as temperature and humidity, which can alter the diffusion rate of the photosensitizer within the photoresist, further impacting pattern formation. In conclusion, existing photoacid generators suffer from numerous drawbacks and fail to meet the current application requirements in the photoresist field. Summary of the Invention

[0004] This invention provides a photoacid-generating agent, which, when applied to photolithography (e.g., ArF or KrF photolithography), can improve the resolution and contrast of the photolithographic pattern.

[0005] The technical solution of the present invention is as follows:

[0006] The compound represented by formula (I):

[0007]

[0008] Among them, R1, R2, R3, and R4 may be the same or different, and are independently selected from C. 1-12 Alkyl, C 1-12 Alkoxy, C 3-20 Cycloalkyl or 3-20 membered heterocyclic groups;

[0009] a, b, and c may be the same or different, and each can be independently selected from 0, 1, 2, 3, 4, or 5.

[0010] d is selected from 0, 1, 2, 3, or 4;

[0011] n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10;

[0012] In the structural formula, the COO-containing portion on the left side of the pyridine is substituted at the ortho, para, or meta position of the pyridine.

[0013] According to an embodiment of the present invention, R1, R2, R3, and R4 may be the same or different, and are independently selected from C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-12 Cycloalkyl or 3-12 membered heterocyclic groups;

[0014] a, b, and c may be the same or different, and each can be independently selected from 0, 1, or 2.

[0015] d is selected from 0, 1 or 2.

[0016] According to an embodiment of the present invention, n is 1, 2, 3 or 4.

[0017] According to an embodiment of the present invention, the compound represented by formula (I) is selected from the following structures:

[0018]

[0019] By introducing a pyridine heterocycle into the compound structure shown in formula (I) of this invention, the volume of the photoacid anion is increased when it is used as a photoacid in photolithography. The lone pair electrons on the pyridine ring can better modulate the acidity of the photoresist and better control the kinetics of the photoresist decomposition process.

[0020] The present invention also provides a method for preparing the compound shown in formula (I), comprising method 1 and method 2:

[0021] Method 1. Compound a reacts with compound b to give the compound shown in formula (I);

[0022]

[0023] Alternatively, method 2. Compound c reacts with compound d to obtain the compound shown in formula (I);

[0024]

[0025] Among them, R1, R2, R3, R4, a, b, c, d, and n have the definitions described above;

[0026] X is a halogen, such as chlorine.

[0027] X4 represents a halide ion, such as a chloride ion.

[0028] The present invention also provides the use of the compound shown in formula (I) above as a photoacid-generating agent.

[0029] The present invention also provides a photoresist composition comprising: a polymer resin and a photoacid generator; wherein the photoacid generator comprises a compound as shown in formula (I) above.

[0030] According to an embodiment of the present invention, the photoacid-producing agent further includes a strongly acidic sulfonium salt photoacid-producing agent; preferably, the strongly acidic sulfonium salt photoacid-producing agent contains sulfate ions and fluorine atoms, and more preferably, the sulfate ions and fluorine atoms are attached to the same carbon atom. Specifically, for example, it is at least one of the following compounds:

[0031]

[0032] According to an embodiment of the present invention, the mass ratio of the compound represented by Formula I to the strongly acidic sulfonium salt photoacid generator in the photoresist composition is 1:(1-20), for example 1:(1-10) or 1:(1-5).

[0033] In some embodiments of the present invention, the polymer resin is a polymer resin capable of ArF or KrF photolithography, such as a polymethyl methacrylate resin system, a phenolic resin system, a polyhydroxystyrene resin system and its derivatives resin system.

[0034] According to an embodiment of the present invention, the polymer resin is prepared by polymerization of at least one of the following monomers:

[0035]

[0036] In some embodiments of the present invention, the polymer resin is prepared by polymerizing monomer mono1 or mono2 with monomer mono7.

[0037] According to an embodiment of the present invention, the photoresist composition further includes a solvent. The solvent is selected from one or more of the following substances: propylene glycol methyl ether, ethyl lactate, butyl acetate, propylene glycol methyl ether acetate, propylene glycol dimethyl ether, ethylene glycol monomethyl ether, cyclohexanone, methyl n-pentanone, methyl isopentanone, cyclopentanone, ethanol, acetonitrile, isopropanol, acetone, and γ-butyrolactone.

[0038] According to an embodiment of the present invention, the photoresist composition further includes a photoacid diffusion inhibitor. The photoacid diffusion inhibitor is a photoacid diffusion inhibitor suitable for triphenylsulfonate salt systems, such as triethanolamine.

[0039] According to an embodiment of the present invention, the photoresist composition is a chemically amplified photoresist.

[0040] According to an embodiment of the present invention, the photoresist composition comprises: a polymer resin, a photoacid generator, a photoacid diffusion inhibitor, and a solvent.

[0041] According to an embodiment of the present invention, the photoresist composition comprises, by weight, 50 to 200 parts of polymer resin, 1 to 30 parts of photoacid-generating agent, 1 to 20 parts of photoacid diffusion inhibitor, and 1,000 to 4,000 parts of solvent.

[0042] According to an embodiment of the present invention, the photoresist composition comprises, by weight, 80-120 parts of polymer resin, 10-15 parts of photoacid-generating agent, 5-12 parts of photoacid diffusion inhibitor and 2000-3500 parts of solvent.

[0043] The present invention also provides a photoresist coating comprising the photoresist composition described above.

[0044] The present invention also provides a method for preparing the photoresist coating, comprising: coating (e.g., spin-coating) the photoresist composition onto a substrate to obtain a photoresist coating.

[0045] In one embodiment, the substrate is a silicon wafer or the like.

[0046] The present invention also provides the application of the photoresist coating as described above in photolithography.

[0047] In one embodiment, the photoresist coating is used for 193nm or 248nm photolithography.

[0048] Beneficial effects

[0049] This invention relates to a class of photoacid generators that can be used in conjunction with strongly acidic sulfonium salt photoacid generators to improve the resolution and contrast of photolithographic patterns. This is primarily because the anions of the photoacid generators contain fluoroalkyl sulfonic acid groups and pyridine groups. In the exposed areas, sulfonic acid is generated after exposure to neutralize the pyridine, forming a strong acid-weak base salt, providing weak acidity. Meanwhile, the pyridine in the unexposed areas is weakly basic, which can neutralize the sulfonic acid groups diffused from the exposed areas, thereby improving exposure contrast.

[0050] Terms and Definitions

[0051] Term "C" 1-12 "alkyl" should be understood to refer to a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably "C". 1-6 Alkyl group. "C" 1-6"Alkyl" means a straight-chain or branched alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers.

[0052] Term "C" 1-12 "Alkoxy" should be understood as -OC 1-12 Alkyl, wherein C 1-12 Alkyl groups have the above definition.

[0053] Term "C" 3-20 "Cycloalkyl" should be understood to refer to a saturated monocyclic or bicyclic hydrocarbon ring having 3 to 20 carbon atoms, preferably "C". 3-12 cycloalkyl. The term "C" 3-12 "Cycloalkyl" should be understood to mean a saturated monovalent monocyclic or bicyclic hydrocarbon ring having 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. The C... 3-12 Cycloalkyl groups can be monocyclic hydrocarbon groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl, or bicyclic hydrocarbon groups such as decahydronaphthalene ring.

[0054] The term "3-20 membered heterocyclic group" refers to a saturated or partially unsaturated monocyclic or bicyclic hydrocarbon ring comprising 3 to 20 ring atoms, wherein one or more ring atoms are heteroatoms or groups selected from N, O, NH, S, S(O) or S(O)2, but excluding ring portions of -OO-, -OS- or -SS-, and the remaining ring atoms are carbon. Preferably, it comprises 3 to 12 ring atoms, wherein 1 to 4 are heteroatoms (e.g., 1, 2, 3, and 4). More preferably, it comprises 3 to 6 ring atoms (e.g., 3, 4, 5, and 6). The heterocyclic group can be connected to the rest of the molecule via any one of the carbon atoms, or a nitrogen atom (if present), or an oxygen or sulfur atom (especially in the case of forming ononium salts). The heterocyclic group can include fused or bridged rings and / or spirocyclic rings. Non-limiting examples of monocyclic heterocyclic groups include azirrobutyl, oxacyclobutyl, pyrrolyl, imidazoalkyl, tetrahydrofuranyl, tetrahydrothiophenyl, dihydroimidazoyl, dihydrofuranyl, dihydropyrazolyl, dihydropyrrolyl, dioxacyclopentenyl, tetrahydropyranyl, pyrrolinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, dithiaalkyl, trithiaalkyl, homopiperazinyl, diazacycloheptyl, etc., preferably piperidinyl or pyrrolyl. Polycyclic heterocyclic groups include spirocyclic, fused-ring, and bridged-ring heterocyclic groups, and may also be benzofused heterocyclic groups such as dihydroisoquinolinyl. The heterocyclic group may be bicyclic, and non-limiting examples include hexahydrocyclopenta[c]pyrrolo-2(1H)-yl and hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl. Heterocyclic groups can also be partially unsaturated, meaning they can contain one or more double bonds. Non-limiting examples include dihydrofuranyl, dihydropyranyl, 2,5-dihydro-1H-pyrroleyl, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl, or 4H-[1,4]thiazinyl. Attached Figure Description

[0055] Figure 1 The photolithographic pattern is shown in Comparative Example 1.

[0056] Figure 2 The photolithographic pattern is shown in Example 1.

[0057] Figure 3 The photolithographic pattern is shown in Example 2. Detailed Implementation

[0058] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0059] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0060] In this application, "photo-induced acid-producing agent" may be abbreviated as "photo-acid".

[0061] Preparation of photoacid

[0062] Preparation Example 1: Preparation Method of Photoacid PAG1

[0063]

[0064] 1 g of 4-bromo-3,3,4,4-tetrafluoro-1-butanol, 3 g of sodium dithionite, and 2.5 g of sodium bicarbonate were placed in separate 250 mL round-bottom flasks. Then, 50 g of acetonitrile and 80 g of water were added as reaction solvents. The reaction mixture was reacted overnight at 75 °C. After heating was stopped, the solvent was evaporated to obtain crude product A1, which was a white solid.

[0065] Place 1g of A1 and 100g of water into a 250mL round-bottom flask, purge the flask with nitrogen three times until it is full of nitrogen, add 5g of hydrogen peroxide dropwise, and after the addition is complete, react at room temperature for 24 hours. After the reaction is complete, add 50g of dichloromethane for extraction, wash the reaction solution with water several times, and finally evaporate the dichloromethane to dryness to obtain 0.85g of crude product A2, which is a white solid.

[0066] 9.88 g of A2 and 11.92 g of triphenylsulfonium chloride were placed in a 250 mL round-bottom flask, along with 50 g of dichloromethane and 76 g of deionized water. The flask was then filled with nitrogen gas three times, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, the reaction solution was washed several times with water, and finally, the dichloromethane was evaporated to dryness to obtain 16.32 g of solid A3.

[0067] 4.88 g of A3, 5 g of triethylamine, and 0.2 g of DMAP (4-dimethylaminopyridine) were placed in a 250 mL round-bottom flask, and 130 g of dichloromethane was added. The flask was then placed in an ice bath and stirred. 2.65 g of nicotinic acid chloride, 0.2 g of triethylamine, and 10 g of dichloromethane were weighed and placed in a dropping funnel. The solution from the dropping funnel was added dropwise into the round-bottom flask, and the mixture was stirred overnight. 66 g of water was added to quench the reaction. The solution was washed several times with water, and finally, the solution was evaporated to dryness to obtain 5.5 g of PAG1, a white solid. 1 H NMR (400MHz, CDCl3) δ = 9.17 (d, J = 1.7Hz, 1H), 8.76 (dd, J = 4.9, 1.7Hz, 1H), 8.28 (dt, J = 8.0, 1.9Hz, 1H) ,7.79–7.68(m,15H),7.40(dd,J=7.9,4.9Hz,1H),4.63(t,J=6.6Hz,2H),2.90(tt,J=18.4,6.6Hz,2H).

[0068] Preparation Example 2: Preparation Method of Photoacid PAG1

[0069]

[0070] 2 g of 4-bromo-3,3,4,4-tetrafluoro-1-butanol, 3 g of triethylamine, and 0.2 g of DMAP (4-dimethylaminopyridine) were placed in a 250 mL round-bottom flask. 130 g of dichloromethane was added, and the flask was placed in an ice bath with stirring. 4 g of nicotinic acid hydrochloride, 1 g of triethylamine, and 10 g of dichloromethane were weighed and placed in a dropping funnel. The funnel was purged with nitrogen three times. The nicotinic acid hydrochloride solution was then added to the round-bottom flask using the dropping funnel, and the mixture was stirred overnight. 66 g of water was added to quench the reaction. The solution was washed several times with water, and finally, the solution was evaporated to dryness to obtain crude product B1.

[0071] 1.65 g of B1, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in separate 250 mL round-bottom flasks. Then, 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the mixture was reacted overnight at 75 °C. Heating was stopped, and the mixture was allowed to return to room temperature. The reaction solvent was evaporated to dryness, and 50 g of dichloromethane was added to dissolve the solid. The solution was then washed three times with 50 g of water, and the dichloromethane was evaporated to dryness to obtain 1.45 g of crude B2, a white solid.

[0072] 1.45 g of B2 and 100 g of water were placed in a 250 mL round-bottom flask. Nitrogen gas was purged three times to fill the flask with nitrogen. 6 g of hydrogen peroxide was added. After the addition was complete, the mixture was allowed to react at room temperature for 24 hours. The reaction was then stopped. The reaction solution was washed with water several times. Finally, the dichloromethane was evaporated to dryness to obtain 1.2 g of B3, which was a white solid.

[0073] 3.53 g of B3 and 2.98 g of triphenylsulfonium chloride were placed in a 250 mL round-bottom flask, along with 50 g of dichloromethane and 76 g of deionized water. The flask was filled with nitrogen gas three times and reacted at room temperature for 24 hours. After the reaction was completed, the reaction solution was washed with water several times, and finally the dichloromethane was evaporated to dryness to obtain 5.1 g of PAG1, which was a white solid.

[0074] Preparation Example 3: Preparation Method of Photoacid PAG2 1

[0075]

[0076] 1.2 g of 5-bromo-4,4,5,5-tetrafluoroalkyl-1-pentanol, 3 g of sodium dithionite, and 2.5 g of sodium bicarbonate were placed in separate 250 mL round-bottom flasks. Then, 50 g of acetonitrile and 80 g of water were added as reaction solvents. The resulting system was reacted overnight at 75 °C. After heating was stopped, the reaction solvent was evaporated to dryness to obtain the crude C1 product, a white solid.

[0077] 1.2g of C1 and 100g of water were placed in a 250mL round-bottom flask. Nitrogen gas was purged three times to fill the flask with nitrogen. Hydrogen peroxide was added dropwise. After the addition was complete, the mixture was allowed to react at room temperature for 24 hours. The reaction was then stopped. 50g of dichloromethane was added for extraction. The reaction solution was washed with water several times. Finally, the dichloromethane was evaporated to dryness to obtain the crude C2 product.

[0078] 10.43 g of C2 and 11.92 g of triphenylsulfonium chloride salt were placed in a 250 mL round-bottom flask, along with 50 g of dichloromethane and 76 g of deionized water. The flask was filled with nitrogen gas by purging it three times. The reaction was carried out at room temperature for 24 hours. The reaction solution was then washed with water several times. Finally, the dichloromethane was evaporated to dryness to obtain 16 g of C3 solid.

[0079] 4.97 g C3, 5 g triethylamine, and 0.2 g DMAP (4-dimethylaminopyridine) were placed in a 250 mL round-bottom flask, and 130 g dichloromethane was added. The flask was then placed in an ice bath and stirred. 2.65 g nicotinic acid chloride, 1 g triethylamine, and 10 g dichloromethane were weighed into a dropping funnel and added dropwise to the round-bottom flask through the funnel, stirring overnight. The reaction was quenched by adding 66 g water. The solution was washed several times with water, and finally evaporated to dryness to obtain 5.4 g PAG2, a white solid. 1 HNMR (400MHz, CDCl3) δ = 9.19 (d, J = 1.6Hz, 1H), 8.75 (dd, J = 4.9, 1.6Hz, 1H), 8.30 (dt, J = 8.0, 1.9Hz, 1H), 7. 77–7.66(m,15H),7.39(dd,J=7.9,4.9Hz,1H),4.37(t,J=6.6Hz,2H),2.61–2.45(m,2H),2.14–2.04(m,2H).

[0080] Preparation Example 4: Preparation Method 2 of Photoacid PAG2

[0081]

[0082] 4-Bromo-3,3,4,4-tetrafluoro-1-pentanol, 3g triethylamine, and 0.2g DMAP (4-dimethylaminopyridine) were placed in a 250mL round-bottom flask, and 130g dichloromethane was added. The flask was then placed in an ice bath and stirred. 4g nicotinic acid chloride, 1g triethylamine, and 10g dichloromethane were weighed and placed in a dropping funnel. The funnel was purged with nitrogen three times. The dichloromethane solution of nicotinic acid chloride was then added dropwise to the round-bottom flask through the dropping funnel, and the mixture was stirred overnight. 66g water was added to quench the reaction. The solution was washed several times with water, and finally, the solution was evaporated to dryness to obtain 1.61g of crude product D1.

[0083] 1.67 g of D1, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in separate 250 mL round-bottom flasks. Then, 50 g of acetonitrile and 80 g of water were added as reaction solvents. The mixture was reacted overnight at 75 °C. After the reaction was stopped, the reaction solvent was evaporated to dryness, dissolved in 50 g of dichloromethane, washed three times with 50 g of water, and the dichloromethane was evaporated to dryness to obtain 1.57 g of D2 as a white solid.

[0084] 1.51 g of D2 and 100 g of water were placed in a 250 mL round-bottom flask. The flask was filled with nitrogen gas by purging it three times. Hydrogen peroxide was added dropwise. After the addition was complete, the mixture was allowed to react at room temperature for 24 hours. The reaction was then stopped. 50 g of dichloromethane was added. The reaction solution was washed with water several times. Finally, the dichloromethane was evaporated to dryness to obtain 1.3 g of D3.

[0085] 3.71 g of D3 and 2.98 g of triphenylsulfonium chloride were placed in a 250 mL round-bottom flask, along with 50 g of dichloromethane and 76 g of deionized water. The flask was filled with nitrogen gas three times and reacted at room temperature for 24 hours. After the reaction was completed, the reaction solution was washed with water several times, and finally the dichloromethane was evaporated to dryness to obtain 5.0 g of PAG2.

[0086] Preparation Example 5: Preparation Method of Photoacid PAG3 1

[0087]

[0088] The synthesis methods for steps 1-3 are the same as those in Preparation Example 1.

[0089] 4.88 g of A3 and 5 g of triethylamine were placed in a 250 mL round-bottom flask, and 130 g of dichloromethane was added. The flask was then placed in an ice bath and stirred. 2.65 g of nicotinic acid chloride, 0.2 g of triethylamine, and 10 g of dichloromethane were weighed and placed in a dropping funnel. The solution from the dropping funnel was added dropwise into the round-bottom flask, and the mixture was stirred overnight. 66 g of water was added to quench the reaction. The solution was washed several times with water, and finally, the solution was evaporated to dryness to obtain 5.2 g of PAG3, a white solid. 1 H NMR (400MHz, CDCl3) δ = 8.74 (d, J = 15.0Hz, 2H), 7.78 (d, J = 15.0Hz, 2H), 7.79–7.68 (m, 15H), 4.63 (t, J = 6.6Hz, 2H), 2.90 (tt, J = 18.4, 6.6Hz, 2H).

[0090] Preparation Example 6: Preparation Method 2 of Photoacid PAG 3

[0091] Place 2g of 4-bromo-3,3,4,4-tetrafluoro-1-butanol and 3g of triethylamine into a 250mL round-bottom flask, add 130g of dichloromethane, and stir in an ice bath. Weigh 4g of isonicotinic acid chloride, 1g of triethylamine, and 10g of dichloromethane into a dropping funnel, purge with nitrogen three times, and add the nicotinic acid chloride solution to the round-bottom flask through the dropping funnel, stirring overnight. Quench the reaction with 66g of water, wash the solution several times with water, and finally evaporate the solution to dryness to obtain the desired crude product.

[0092] 2.12 g of the crude product, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in separate 250 mL round-bottom flasks. Then, 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the reaction was carried out overnight at 75 °C. Heating was stopped, and the temperature was allowed to return to room temperature. The reaction solvent was evaporated to dryness, and 50 g of dichloromethane was added to dissolve the solid. The solution was washed three times with 50 g of water, and the dichloromethane was evaporated to dryness to obtain 1.62 g of the crude product, which was a white solid.

[0093] Place 1.62g of the crude product from the previous step and 100g of water into a 250mL round-bottom flask. Replace the nitrogen gas three times to fill the round-bottom flask with nitrogen. Add 6g of hydrogen peroxide. After the addition is complete, react at room temperature for 24 hours. After the reaction is stopped, add 50g of dichloromethane. Wash the reaction solution with water several times. Finally, evaporate the dichloromethane to dryness to obtain 1.5g of white solid.

[0094] 3.53 g of white solid and 2.98 g of triphenylsulfonium chloride salt were placed in a 250 mL round-bottom flask, along with 50 g of dichloromethane and 76 g of deionized water. The flask was filled with nitrogen gas three times and reacted at room temperature for 24 hours. After the reaction was completed, the reaction solution was washed with water several times, and finally the dichloromethane was evaporated to dryness to obtain 4.9 g of PAG3, which was a white solid.

[0095] Preparation Example 7: Preparation Method of Photoacid PAG4 1

[0096]

[0097] The synthesis methods for steps 1-3 are the same as those in Preparation Example 1.

[0098] 4.88 g of A3 and 5 g of triethylamine were placed in a 250 mL round-bottom flask, and 130 g of dichloromethane was added. The flask was then placed in an ice bath and stirred. 2.65 g of pyridine-2-formyl chloride hydrochloride, 0.2 g of triethylamine, and 10 g of dichloromethane were weighed into a dropping funnel and added dropwise to the round-bottom flask. The mixture was stirred overnight. 66 g of water was added to quench the reaction. The solution was washed several times with water, and finally, the solution was evaporated to dryness to obtain 4.8 g of PAG4, a white solid. 1H NMR (400MHz, CDCl3) δ = 8.82 (dd, J = 14.7, 3.4Hz, 1H), 8.23 ​​(dd, J = 14.7, 3.2Hz, 1H), 7.89 (dtd, J = 47.1,14.9,3.2Hz,2H),7.79–7.68(m,15H),4.63(t,J=6.6Hz,2H),2.90(tt,J=18.4,6.6Hz,2H).

[0099] Preparation Example 8: Preparation Method 2 of Photoacid PAG4

[0100] 2 g of 4-bromo-3,3,4,4-tetrafluoro-1-butanol and 3 g of triethylamine were placed in a 250 mL round-bottom flask, and 130 g of dichloromethane was added. The flask was then placed in an ice bath and stirred. 4 g of pyridine-2-carboxyl chloride hydrochloride, 1 g of triethylamine, and 10 g of dichloromethane were weighed and placed in a dropping funnel, which was then purged with nitrogen three times. Nicotinic acid chloride solution was added to the round-bottom flask through the dropping funnel, and the mixture was stirred overnight. 66 g of water was added to quench the reaction, and the solution was washed several times with water. Finally, the solution was evaporated to dryness to obtain the desired crude product.

[0101] 2.12 g of the crude product, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in separate 250 mL round-bottom flasks. Then, 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the reaction was carried out overnight at 75 °C. Heating was stopped, and the temperature was allowed to return to room temperature. The reaction solvent was evaporated to dryness, and 50 g of dichloromethane was added to dissolve the solid. The solution was washed three times with 50 g of water, and the dichloromethane was evaporated to dryness to obtain 1.7 g of the crude product as a white solid.

[0102] Place 1.62g of the crude product from the previous step and 100g of water into a 250mL round-bottom flask. Replace the nitrogen gas three times to fill the round-bottom flask with nitrogen. Add 6g of hydrogen peroxide. After the addition is complete, react at room temperature for 24 hours. After the reaction is stopped, add 50g of dichloromethane. Wash the reaction solution with water several times. Finally, evaporate the dichloromethane to dryness to obtain 1.8g of white solid.

[0103] 3.53 g of white solid and 2.98 g of triphenylsulfonium chloride salt were placed in a 250 mL round-bottom flask, along with 50 g of dichloromethane and 76 g of deionized water. The flask was filled with nitrogen gas three times and reacted at room temperature for 24 hours. After the reaction was completed, the reaction solution was washed with water several times, and finally the dichloromethane was evaporated to dryness to obtain 4.8 g of PAG4, which was a white solid.

[0104] Synthesis of Type 1 Resin

[0105] 98.145 g of 1-(1-methylethyl)cyclopentylisobutylenoate and 85.08 g of 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate were added to a 1000 mL round-bottom flask, followed by 200 g of propylene glycol monomethyl ether acetate. The reaction temperature was raised to 80 °C, and finally 5 g of CABN (azoisobutyl cyanoformamide) and 4 g of n-dodecyl mercaptan were added. After reacting for 24 h, the product was precipitated directly with water.

[0106] Type 2-10 resins can be prepared by referring to the preparation method of Type 1 resins.

[0107] The components of Type 1-10 active resins are shown in Table 1.

[0108] Preparation of photoresist composition

[0109] Using the proportions shown in Table 2, 10g of active resin, photoacid-generating agent, 0.06g of photoacid diffusion inhibitor triethanolamine, 54g of propylene glycol monomethyl ether acetate, and 36g of cyclohexanone were added to a 150mL glass bottle. The mixture was shaken in the bottle at room temperature for 24 hours to ensure complete dissolution, thus obtaining the photoresist composition. The photoresist composition was filtered through a 0.22μm filter, and photolithography experiments were then performed.

[0110]

[0111] Table 1. Components of Active Resin

[0112]

[0113] In the table above, " / " indicates that the component is not present.

[0114]

[0115] Table 2. Amount of each component added

[0116]

[0117] In the table above, " / " indicates that the component is not present.

[0118] ArF lithography experiment

[0119] First, a resist coating was spin-coated onto a 12-inch silicon wafer at 205°C for 60 seconds at a speed of 1500 rpm. Then, the photoresist composition prepared in Example 10 above was uniformly spin-coated onto the silicon wafer at a speed of 1500 rpm, resulting in a coating thickness of 800 Å. The wafer was pre-baked at 90°C for 1 minute; after exposure, it was post-baked at 90°C for 1 minute; after the silicon wafer cooled, it was developed with 2.38% TMAH developer for half a minute, and finally rinsed with deionized water for half a minute to form the desired photolithographic pattern. The depth of focus (DOF) and exposure latitude (EL) of the obtained pattern are shown in Table 3 below.

[0120] Table 3. Photoresist test performance results

[0121]

[0122]

[0123] The above test data on etching with five photoacids show that, compared with photoresist compositions containing only photoacid PAG5, PAG1, PAG2, PAG3, and PAG4 exhibit better resolution and contrast for the same resin. This is because the anions in PAG1, PAG2, PAG3, and PAG4 contain fluoroalkyl sulfonic acid groups and pyridine groups. In the exposed areas, sulfonic acid is generated after exposure to neutralize pyridine, forming a strong acid-weak base salt, providing weak acidity. Meanwhile, the pyridine in the unexposed areas provides weak baseity, which can neutralize the sulfonic acid groups diffused from the exposed areas, thereby improving exposure contrast.

[0124] Figure 1 The photolithographic pattern is shown in Comparative Example 1. Figure 2 The photolithographic pattern is that of Example 1. Figure 3 This is the photolithographic pattern for Example 2. (Comparison) Figure 1-3 It can be seen that, compared to photoresist formulations that only add PAG5, photoresist formulations that add PAG1 or PAG2 can significantly improve EL (energy margin) and DOF (depth of focus).

[0125] The photoacidity of this application has the same effect in other photolithography (e.g., KrF).

[0126] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The compound represented by formula (I): （I） in, R1, R2, R3, and R4 may be the same or different, and are independently selected from C. 1-12 Alkyl, C 1-12 Alkoxy; a, b, and c may be the same or different, and each can be independently selected from 0, 1, 2, or 3; d is selected from 0, 1, or 2; n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; In the structural formula, the COO-containing portion on the left side of the pyridine is substituted at the ortho, para, or meta position of the pyridine.

2. The compound according to claim 1, wherein, R1, R2, R3, and R4 may be the same or different, and are independently selected from C. 1-6 Alkyl, C 1-6 Alkoxy; a, b, and c may be the same or different, and each can be independently selected from 0, 1, or 2. d is selected from 0, 1, or 2; n can be 1, 2, 3 or 4.

3. The compound according to claim 1 or 2, wherein, The compound represented by formula (I) is selected from the following structures: PAG3 PAG4。 4. A method for preparing the compound according to any one of claims 1-3, wherein, Including Method 1 and Method 2: Method 1. Compound a reacts with compound b to give the compound shown in formula (I); Alternatively, method 2. Compound c reacts with compound d to give the compound shown in formula (I); Wherein, R1, R2, R3, R4, a, b, c, d, and n have the definitions described in any one of claims 1-3; X is a halogen, and X4 is a halide ion.

5. Use of the compound according to any one of claims 1-3 as a photoacid-producing agent.

6. A photoresist composition comprising: Polymer resin and photoacid generator; wherein the photoacid generator includes the compound of formula (I) as described in any one of claims 1-3.

7. The photoresist composition according to claim 6, wherein, The photoacid-generating agent further includes a strongly acidic sulfonium salt photoacid-generating agent; the strongly acidic sulfonium salt photoacid-generating agent is at least one of the following compounds: 、 、 、 、 、 、 、 、 、 、 。 8. The photoresist composition according to claim 6 or 7, wherein, The polymer resin is prepared by polymerization using at least one of the following monomers: 。 9. A photoresist coating comprising the photoresist composition of any one of claims 6-8.

10. The method for preparing the photoresist coating according to claim 9, wherein, The method includes coating a substrate with the photoresist composition according to any one of claims 6-8 to obtain a photoresist layer.

11. The application of the photoresist coating of claim 9 in photolithography.

12. The application according to claim 11, wherein, The photoresist coating is used for 193nm or 248nm photolithography.

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