Photoinduced acid generator, preparation method thereof and photoresist composition containing photoinduced acid generator

Abstract

The invention relates to a photoacid generator, a preparation method thereof and a photoresist composition containing the photoacid generator. The photoacid generator has a structure as shown in a formula (I). The photoacid generator can be used together with a strongly acidic sulfonium salt photoacid generator, so that the resolution ratio and the contrast ratio of a photoetching pattern are improved. # imgabs0 #

Description

Technical Field

[0001] The present application belongs to the technical field of photoresists, and specifically relates to a photoacid generator and a preparation method thereof, and a photoresist composition containing the photoacid generator. Background Art

[0002] Photoacid generator is an important component of chemically amplified photoresist. It generates acid through photochemical activation, which then diffuses in the photoresist system and undergoes an acid-catalyzed reaction. This process causes the protective group on the photoresist resin to decompose and eventually generate carboxylic acid. Subsequently, the carboxylic acid is neutralized into an organic salt by an alkaline developer and dissolved in an aqueous solution to form a pattern. Throughout the process, the photoacid generator maintains its original function while improving the quality and readability of the photoresist.

[0003] In the prior art, the diffusion rate of photoacid in the photoresist system is relatively fast due to the small volume of anions in the photoacid generator, which may lead to the following problems: first, the rapidly diffusing anions will lead to the generation of edge roughness (LER) and irregular morphology, and may also cause photoresist residue and glue backflow; second, the rapidly diffusing anions will quickly penetrate into the unexposed area of ​​the photoresist, causing the photoresist in the unexposed area to partially decompose, thereby affecting the shape accuracy of the photolithographic pattern. The rapidly diffusing anions will cause the photoresist to react too fast, causing the photoresist to decompose unevenly, thereby affecting the formation of the photolithographic pattern. The rapidly diffusing anions are easily affected by environmental factors such as temperature and humidity, and these changes will cause the diffusion rate of the photosensitizer in the photoresist to change, thereby affecting the formation of the photolithographic pattern. In short, the photoacid generator in the prior art has many defects and is difficult to meet the current application needs in the field of photoresists. Summary of the invention

[0004] The invention provides a photoacid generator, which is applied to photolithography (such as ArF or KrF photolithography) to improve the resolution and contrast of photolithography patterns.

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

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

[0007]

[0008] Wherein, R1, R2, R3 and R4 are 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 group;

[0009] a, b and c are the same or different and are 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] The COO-containing part on the left side of pyridine in the structural formula is substituted at the ortho-position, para-position or meta-position of pyridine.

[0013] According to an embodiment of the present invention, R1, R2, R3 and R4 are 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 group;

[0014] a, b and c are the same or different and are 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] After the pyridine heterocycle is introduced into the compound structure shown in formula (I) of the present invention, it is used as a photoacid for photolithography to expand the volume of the photoacid anion. The lone pair of electrons on the pyridine ring can better adjust 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 represented by formula (I), including method 1 and method 2:

[0021] Method 1. Compound a reacts with compound b to obtain a compound represented by formula (I);

[0022]

[0023] Alternatively, method 2. Compound c reacts with compound d to obtain a compound represented by formula (I);

[0024]

[0025] wherein R1, R2, R3, R4, a, b, c, d and n are as defined above;

[0026] X is halogen, such as chlorine.

[0027] X4 is a halogen ion, such as a chloride ion.

[0028] The present invention also provides the use of the compound represented by the above formula (I) as a photoacid generator.

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

[0030] According to an embodiment of the present invention, the photoacid generator further comprises a strongly acidic sulfonium salt photoacid generator; preferably, the strongly acidic sulfonium salt photoacid generator contains sulfate ions and fluorine atoms, and preferably, the sulfate ions and fluorine atoms are connected to the same carbon atom. Specifically, for example, 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 that can be subjected to ArF or KrF photolithography, such as a polymethacrylate resin system, a phenolic resin system, a polyhydroxystyrene and a resin system derived from the same.

[0034] According to an embodiment of the present invention, the polymer resin is prepared by polymerizing 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 comprises 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-amyl ketone, methyl isoamyl ketone, cyclopentanone, ethanol, acetonitrile, isopropanol, acetone, and γ-butyrolactone.

[0038] According to an embodiment of the present invention, the photoresist composition further comprises a photoacid diffusion inhibitor. The photoacid diffusion inhibitor is a photoacid diffusion inhibitor suitable for triphenylsulfonium sulfonate salt system, 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 includes: 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 includes, by mass, 50 to 200 parts of a polymer resin, 1 to 30 parts of a photoacid generator, 1 to 20 parts of a photoacid diffusion inhibitor, and 1000 to 4000 parts of a solvent.

[0042] According to an embodiment of the present invention, the photoresist composition includes, by mass, 80 to 120 parts of a polymer resin, 10 to 15 parts of a photoacid generator, 5 to 12 parts of a photoacid diffusion inhibitor, and 2000 to 3500 parts of a solvent.

[0043] The present invention also provides a photoresist coating, which comprises the photoresist composition as described above.

[0044] The present invention also provides a method for preparing the photoresist coating, comprising: coating (such as spin coating) the photoresist composition on 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 use of the photoresist coating as described above in photolithography.

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

[0048] Beneficial Effects

[0049] The present invention relates to a type of photoacid generator, which can be used together with a strongly acidic sulfonium salt photoacid generator to improve the resolution and contrast of a photolithographic pattern. This is mainly because the anion of the photoacid generator contains a fluoroalkanesulfonic acid group and a pyridine group, and the exposed area generates sulfonic acid after exposure to neutralize pyridine to form a strong acid weak base salt, providing weak acidity; while the pyridine in the unexposed area is weakly alkaline, which can neutralize the sulfonic acid group diffused from the exposed area to improve the exposure contrast.

[0050] Terms and Definitions

[0051] The term "C 1-12 "Alkyl" is understood to mean a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably "C 1-6 Alkyl". "C 1-6The term "alkyl" refers to straight-chain and branched alkyl groups 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, 1,2-dimethylbutyl, or the like or isomers thereof.

[0052] The term "C 1-12 "Alkoxy" is understood to mean -OC 1-12 Alkyl, where C 1-12 Alkyl has the above definition.

[0053] The term "C 3-20 "Cycloalkyl" is understood to mean a saturated monocyclic or bicyclic hydrocarbon ring having 3 to 20 carbon atoms, preferably "C 3-12 The term "Cycloalkyl" 3-12 "Cycloalkyl" is 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. 3-12 The cycloalkyl group may be a monocyclic hydrocarbon group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, or a bicyclic hydrocarbon group such as a decalin ring.

[0054] The term "3-20 membered heterocyclyl" means a saturated or partially unsaturated monocyclic or bicyclic hydrocarbon ring containing 3 to 20 ring atoms, wherein one or more ring atoms are selected from N, O, NH, S, S(O) or S(O)2 heteroatoms or atomic groups, but excluding -OO-, -OS- or -SS- ring parts, and the remaining ring atoms are carbon. Preferably, 3 to 12 ring atoms are contained, wherein 1-4 are heteroatoms (e.g., 1, 2, 3 and 4). More preferably, 3 to 6 ring atoms (e.g., 3, 4, 5, 6) are contained. The heterocyclyl can be connected to the rest of the molecule through any one of the carbon atoms or nitrogen atom (if present) or oxygen or sulfur atom (especially in the case of forming an onium salt). The heterocyclyl can include fused or bridged rings and / or spirocyclic rings. Non-limiting examples of monocyclic heterocyclic groups include azetidinyl, oxetanyl, pyrrolidinyl, imidazolidinyl, tetrahydrofuranyl, tetrahydrothienyl, dihydroimidazolyl, dihydrofuranyl, dihydropyrazolyl, dihydropyrrolyl, dioxolyl, tetrahydropyranyl, pyrrolinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, dithianyl, trithianyl, homopiperazinyl, diazepanyl, etc., preferably piperidinyl, pyrrolidinyl. Polycyclic heterocyclic groups include spirocyclic, fused ring and bridged heterocyclic groups, and may also be benzo-fused heterocyclic groups such as dihydroisoquinolinyl. The heterocyclic group may be bicyclic, and non-limiting examples thereof include hexahydrocyclopenta [c] pyrrole -2 (1H) -yl, hexahydropyrrolo [1,2-a] pyrazine -2 (1H) -yl. The heterocyclyl group may also be partially unsaturated, ie it may contain one or more double bonds, non-limiting examples of which include dihydrofuranyl, dihydropyranyl, 2,5-dihydro-1H-pyrrolyl, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl or 4H-[1,4]thiazinyl. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is the photolithography pattern of Comparative Example 1.

[0056] Figure 2 This is the photolithography pattern of Example 1.

[0057] Figure 3 This is the photolithography pattern of Example 2. DETAILED DESCRIPTION

[0058] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

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

[0060] In this application, "photoacid generator" may be referred to as "photoacid" for short.

[0061] Preparation of photoacid

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

[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 a 250 mL round-bottom flask, and then 50 g of acetonitrile and 80 g of water were added as reaction solvents. The reaction solution was reacted at 75° C. overnight. The reaction was stopped by heating, and the solvent was dried by spin drying to obtain a crude product A1 as a white solid.

[0065] 1 g of A1 and 100 g of water were placed in a 250 mL round-bottom flask, and nitrogen was replaced three times to fill the round-bottom flask with nitrogen. 5 g of hydrogen peroxide was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 24 hours. After the reaction was terminated, 50 g of dichloromethane was added for extraction. The reaction solution was washed with water several times, and the dichloromethane was finally spin-dried to obtain 0.85 g of A2 crude product as 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, and 50 g of dichloromethane and 76 g of deionized water were added. The nitrogen was replaced three times to fill the round-bottom flask with nitrogen, and the reaction was carried out at room temperature for 24 hours. The reaction was terminated, the reaction solution was washed with water several times, and the dichloromethane was finally spin-dried to obtain 16.32 g of A3 solid.

[0067] 4.88g A3, 5g triethylamine, 0.2g DMAP (4-dimethylaminopyridine) were placed in a 250mL round-bottom flask, 130g dichloromethane was added, and the round-bottom flask was placed in an ice bath for stirring. 2.65g nicotinyl chloride hydrochloride, 0.2g triethylamine and 10g dichloromethane were weighed and placed in a dropping funnel, and the solution in the dropping funnel was dripped into the round-bottom flask and stirred overnight. 66g water was added to quench the reaction, the solution was washed with water several times, and finally the solution was spin-dried to obtain 5.5g PAG1 as 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: Photoacid PAG1 Preparation Method 2

[0069]

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

[0071] 1.65 g of B1, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in a 250 mL round-bottom flask, and then 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the mixture was reacted overnight at 75° C. The reaction was stopped and heated, and the temperature was restored to room temperature. The reaction solvent was dried by spin drying, 50 g of dichloromethane was added to dissolve, and then 50 g of water was added to wash three times, and the dichloromethane was dried by spin drying to obtain 1.45 g of B2 crude product as a white solid.

[0072] 1.45 g of B2 and 100 g of water were placed in a 250 mL round-bottom flask, and the nitrogen was replaced three times to fill the round-bottom flask with nitrogen. 6 g of hydrogen peroxide was added. After the addition was complete, the reaction was allowed to react at room temperature for 24 hours. The reaction was terminated, and the reaction solution was washed with water several times. Finally, the dichloromethane was spin-dried to obtain 1.2 g of B3 as 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, and 50 g of dichloromethane and 76 g of deionized water were added. The nitrogen was replaced three times to fill the round-bottom flask with nitrogen. The reaction was carried out at room temperature for 24 hours. The reaction was terminated, and the reaction solution was washed with water several times. Finally, the dichloromethane was spin-dried to obtain 5.1 g of PAG1 as a white solid.

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

[0075]

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

[0077] Put 1.2g C1 and 100g water into a 250mL round-bottom flask, replace nitrogen three times to fill the round-bottom flask with nitrogen, add hydrogen peroxide dropwise, react at room temperature for 24 hours after the addition is complete, terminate the reaction, add 50g of dichloromethane for extraction, wash the reaction solution with water several times, and finally spin-dry the dichloromethane to obtain a crude product of C2.

[0078] 10.43 g of C2 and 11.92 g of triphenylsulfonium chloride were placed in a 250 mL round-bottom flask, and 50 g of dichloromethane and 76 g of deionized water were added. The nitrogen was replaced three times to fill the round-bottom flask with nitrogen. The reaction was carried out at room temperature for 24 hours. The reaction was terminated, the reaction solution was washed with water several times, and the dichloromethane was finally spin-dried to obtain 16 g of C3 solid.

[0079] 4.97g C3, 5g triethylamine, 0.2g DMAP (4-dimethylaminopyridine) were placed in a 250mL round-bottom flask, 130g dichloromethane was added, and the round-bottom flask was placed in an ice bath for stirring. 2.65g nicotinyl chloride hydrochloride, 1g triethylamine and 10g dichloromethane were weighed and placed in a dropping funnel, and nicotinyl chloride hydrochloride was added dropwise to the round-bottom flask through the dropping funnel, and stirred overnight. 66g water was added to quench the reaction, and the solution was washed with water several times, and finally the solution was spin-dried to obtain 5.4g PAG2 as 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: Photoacid PAG2 Preparation Method 2

[0081]

[0082] Place 4-bromo-3,3,4,4-tetrafluoro-1-pentanol, 3g triethylamine, and 0.2g DMAP (4-dimethylaminopyridine) in a 250mL round-bottom flask, add 130g dichloromethane, and place the round-bottom flask in an ice bath for stirring. Weigh 4g nicotinyl chloride hydrochloride, 1g triethylamine, and 10g dichloromethane into a dropping funnel, replace nitrogen three times, and drip a dichloromethane solution of nicotinyl chloride hydrochloride into the round-bottom flask through the dropping funnel and stir overnight. Add 66g water to quench the reaction, wash the solution with water several times, and finally spin dry the solution to obtain 1.61g D1 crude product.

[0083] 1.67 g of D1, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in a 250 mL round-bottom flask, and then 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the system was reacted overnight at 75° C. After the reaction was stopped, the reaction solvent was dried by spin drying, 50 g of dichloromethane was added to dissolve, 50 g of water was added to wash 3 times, and the dichloromethane was dried by spin drying 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, and the nitrogen was replaced three times to fill the round-bottom flask with nitrogen. Hydrogen peroxide was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 24 hours. After the reaction was terminated, 50 g of dichloromethane was added, and the reaction solution was washed with water several times. Finally, the dichloromethane was spin-dried 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, and 50 g of dichloromethane and 76 g of deionized water were added. The nitrogen was replaced three times to fill the round-bottom flask with nitrogen. The reaction was carried out at room temperature for 24 hours. After the reaction was terminated, the reaction solution was washed with water several times, and the dichloromethane was finally dried to obtain 5.0 g of PAG2.

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

[0087]

[0088] The synthesis method of steps 1 to 3 is the same as that of Preparation Example 1.

[0089] 4.88g A3 and 5g triethylamine were placed in a 250mL round-bottom flask, 130g dichloromethane was added, and the round-bottom flask was placed in an ice bath for stirring. 2.65g nicotinoyl chloride isohydrochloride, 0.2g triethylamine and 10g dichloromethane were weighed and placed in a dropping funnel, and the solution in the dropping funnel was dripped into the round-bottom flask and stirred overnight. 66g water was added to quench the reaction, the solution was washed with water several times, and finally the solution was spin-dried to obtain 5.2g PAG3 as 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: Photoacid PAG 3 Preparation Method 2

[0091] Place 2g of 4-bromo-3,3,4,4-tetrafluoro-1-butanol and 3g of triethylamine in a 250mL round-bottom flask, add 130g of dichloromethane, and place the round-bottom flask in an ice bath for stirring. Weigh 4g of nicotinoyl chloride isohydrochloride, 1g of triethylamine, and 10g of dichloromethane and place them in a dropping funnel, replace nitrogen three times, add nicotinoyl chloride hydrochloride solution to the round-bottom flask through the dropping funnel, and stir overnight. Add 66g of water to quench the reaction, wash the solution with water several times, and finally spin dry the solution to obtain the desired crude product.

[0092] 2.12 g of crude product, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in a 250 mL round-bottom flask, and then 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the reaction was allowed to proceed overnight at 75° C. The reaction was stopped from heating, and the temperature was restored to room temperature, the reaction solvent was dried by spin drying, 50 g of dichloromethane was added to dissolve, 50 g of water was added to wash 3 times, and dichloromethane was dried by spin drying to obtain 1.62 g of crude product as a white solid.

[0093] 1.62 g of the crude product from the previous step and 100 g of water were placed in a 250 mL round-bottom flask, and the nitrogen was replaced three times to fill the round-bottom flask with nitrogen. 6 g of hydrogen peroxide was added. After the addition was complete, the reaction was allowed to react at room temperature for 24 hours. The reaction was terminated, 50 g of dichloromethane was added, the reaction solution was washed with water several times, and the dichloromethane was finally spin-dried to obtain 1.5 g of a white solid.

[0094] 3.53 g of white solid and 2.98 g of triphenylsulfonium chloride were placed in a 250 mL round-bottom flask, and 50 g of dichloromethane and 76 g of deionized water were added. The nitrogen was replaced three times to fill the round-bottom flask with nitrogen. The reaction was carried out at room temperature for 24 hours. The reaction was terminated, and the reaction solution was washed with water several times. Finally, the dichloromethane was spin-dried to obtain 4.9 g of PAG3 as a white solid.

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

[0096]

[0097] The synthesis method of steps 1 to 3 is the same as that of Preparation Example 1.

[0098] 4.88g A3 and 5g triethylamine were placed in a 250mL round-bottom flask, 130g dichloromethane was added, and the round-bottom flask was placed in an ice bath for stirring. 2.65g pyridine-2-carbonyl chloride hydrochloride, 0.2g triethylamine and 10g dichloromethane were weighed and placed in a dropping funnel, dropped into a round-bottom flask, and stirred overnight. 66g water was added to quench the reaction, the solution was washed with water several times, and finally the solution was spin-dried to obtain 4.8g PAG4 as 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: Photoacid PAG4 Preparation Method 2

[0100] 2g 4-bromo-3,3,4,4-tetrafluoro-1-butanol and 3g triethylamine were placed in a 250mL round-bottom flask, 130g dichloromethane was added, and the round-bottom flask was placed in an ice bath for stirring. 4g pyridine-2-carbonyl chloride hydrochloride, 1g triethylamine and 10g dichloromethane were weighed and placed in a dropping funnel, and nitrogen was replaced 3 times. Nicotinoyl chloride hydrochloride solution was added to the round-bottom flask through a dropping funnel and stirred overnight. 66g water was added to quench the reaction, the solution was washed with water several times, and the solution was finally spin-dried to obtain the desired crude product.

[0101] 2.12 g of crude product, 3 g of sodium dithionite, and 2 g of sodium bicarbonate were placed in a 250 mL round-bottom flask, and then 50 g of acetonitrile and 80 g of water were added as reaction solvents, and the reaction was allowed to proceed overnight at 75 ° C. The reaction was stopped and the temperature was restored to room temperature. The reaction solvent was dried by spin drying, 50 g of dichloromethane was added to dissolve, 50 g of water was added to wash 3 times, and dichloromethane was dried by spin drying to obtain 1.7 g of crude product as a white solid.

[0102] 1.62 g of the crude product from the previous step and 100 g of water were placed in a 250 mL round-bottom flask, and the nitrogen was replaced three times to fill the round-bottom flask with nitrogen. 6 g of hydrogen peroxide was added. After the addition was complete, the reaction was allowed to proceed at room temperature for 24 hours. The reaction was terminated, 50 g of dichloromethane was added, and the reaction solution was washed with water several times. Finally, the dichloromethane was spin-dried to obtain 1.8 g of a white solid.

[0103] 3.53 g of white solid and 2.98 g of triphenylsulfonium chloride were placed in a 250 mL round-bottom flask, and 50 g of dichloromethane and 76 g of deionized water were added. The nitrogen was replaced three times to fill the round-bottom flask with nitrogen. The reaction was carried out at room temperature for 24 hours. The reaction was terminated, the reaction solution was washed with water several times, and the dichloromethane was finally dried to obtain 4.8 g of PAG4 as a white solid.

[0104] Synthesis of Type 1 resin

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

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

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

[0108] Preparation of photoresist compositions

[0109] Using the ratio shown in Table 2 below, 10 g of active resin, photoacid generator, 0.06 g of photoacid diffusion inhibitor triethanolamine, 54 g of propylene glycol monomethyl ether acetate and 36 g of cyclohexanone were added to a 150 mL glass bottle. At room temperature, the mixture was shaken in the bottle for 24 hours to fully dissolve it to prepare a photoresist composition. The photoresist composition was filtered with a 0.22 μm filter and then a photolithography experiment was performed.

[0110]

[0111] Table 1 Active resin components

[0112]

[0113] In the above table, “ / ” means that the component is not contained.

[0114]

[0115] Table 2 Addition amount of each component

[0116]

[0117] In the above table, “ / ” means that the component is not contained.

[0118] ArF lithography experiment

[0119] First, a layer of resist coating was spin-coated on a 12-inch silicon wafer at a temperature of 205°C, a time of 60s, and a rotation speed of 1500rpm; then the photoresist composition prepared in Example 10 was evenly spin-coated on the silicon wafer at a rotation speed of 1500rpm, and the coating thickness was 800A; pre-baked at 90°C for 1min; after exposure, post-baked at 90°C for 1min; after waiting for the silicon wafer to cool, developed with 2.38% TMAH developer for half a minute, and finally rinsed with deionized water for half a minute to form the required photolithography 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] From the test data of etching with the five photoacids above, it can be seen that compared with the photoresist composition with only the photoacid PAG5 added, PAG1, PAG2, PAG3 and PAG4 have better resolution and contrast for the same resin. Thanks to the fact that the anions in PAG1, PAG2, PAG3 and PAG4 contain fluoroalkanesulfonic acid groups and pyridine groups, the sulfonic acid generated in the exposed area after exposure neutralizes the pyridine to form a strong acid and weak base salt, providing weak acidity; while the pyridine in the unexposed area provides weak alkalinity, which can neutralize the sulfonic acid groups diffused from the exposed area to improve the exposure contrast.

[0124] Figure 1 is the photolithography pattern of Comparative Example 1, Figure 2 is the photolithography pattern of Example 1, Figure 3 This is the photolithography pattern of Example 2. Figure 1-3 It can be seen that compared with the photoresist formula with only PAG5 added, the photoresist formula with additional addition of PAG1 or PAG2 can significantly improve EL (exposure energy margin) and DOF (depth of focus).

[0125] The photoacid of the present application has the same effect in other photolithography (eg KrF).

[0126] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

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

2. The compound according to claim 1, wherein R1, R2, R3 and R4 are 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 group; a, b and c are the same or different and are independently selected from 0, 1 or 2; d is selected from 0, 1 or 2; n is 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:

4. A method for preparing a compound according to any one of claims 1 to 3, wherein: Including method 1 and method 2: Method 1. Compound a reacts with compound b to obtain a compound represented by formula (I); Alternatively, method 2. Compound c reacts with compound d to obtain a compound represented by formula (I); Wherein, R1, R2, R3, R4, a, b, c, d and n have the meanings as described in any one of claims 1 to 3; X is a halogen, and X4 is a halide ion.

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

6. A photoresist composition comprising: A polymer resin and a photoacid generator; wherein the photoacid generator comprises a compound represented by formula (I) according to any one of claims 1 to 3.

7. The photoresist composition according to claim 6, wherein The photoacid generator further includes a strongly acidic sulfonium salt photoacid generator; the strongly acidic sulfonium salt photoacid generator is, for example, at least one of the following compounds: Preferably, the polymer resin is prepared by polymerizing at least one of the following monomers:

8. A photoresist coating comprising the photoresist composition according to claim 6 or 7.

9. The method for preparing the photoresist coating according to claim 8, wherein: The method comprises coating the photoresist composition according to claim 6 or 7 on a substrate to obtain a photoresist layer.

10. Use of the photoresist coating according to claim 8 in photolithography; Preferably, the photoresist coating is used for 193nm lithography or 248nm lithography.

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