A sulfonium sulfonate photoacid generator and its synthesis method and application

Abstract

The present invention relates to a sulfonium sulfonate photoacid generator represented by Formula I, a synthesis method thereof, and a photoresist composition containing the photoacid generator. The photoacid generator of the present invention has a relatively large molecular weight, which can reduce diffusion of the photoacid generator during use, thereby improving the process window and edge roughness of the photoresist. Furthermore, the photoacid generator of the present invention is simple to prepare, and a high-purity product can be obtained through a simple recrystallization step. Furthermore, the photoacid generator of the present invention significantly improves the edge roughness and DOF of the resulting photolithographic pattern compared to existing photoacid generators for ArF lithography.

Description

Technical Field

[0001] The invention belongs to the technical field of photolithographic materials, and particularly relates to a sulfonium sulfonate photoacid generator, a synthesis method thereof and a photoresist composition containing the photoacid generator. Background Art

[0002] Photoresist, also known as photoresist, is a crucial core material in the photolithography process. It is an etch-resistant material whose solubility changes upon exposure to electromagnetic waves such as ultraviolet light, X-rays, or electron beams. It serves as a transfer agent and is widely used in fine-grained processing applications such as displays, integrated circuits, micro-electromechanical systems (MEMS), and optoelectronic devices. In recent years, the rapid development of large-scale integrated circuits and the display industry has placed higher demands on photolithography processes: achieving more refined and higher-resolution replica patterns.

[0003] After semiconductor integrated circuit lithography began using deep ultraviolet (DUV) light sources, chemical amplification (CAR) technology gradually became a mainstream industry application. In CAR photoresist technology, the resin is polyethylene, which is protected by chemical groups and therefore difficult to dissolve. Therefore, CAR photoresist requires a photoacid generator (PAG) as a photoinitiator. When the photoresist is exposed, the PAG in the exposed area will produce an acid. This acid acts as a catalyst during the post-heat bake process, removing the resin's protecting groups and making the resin more soluble. CAR photoresist has an exposure speed 10 times that of diazonaphthoquinone (DNQ) photoresist and has excellent optical sensitivity to DUV light sources, while also offering advantages such as high contrast and high resolution.

[0004] Chemically amplified photoresists generally consist of four main components: a film-forming resin, a photoacid generator, additives, and a solvent. The mechanism of action is that the photoacid generator absorbs light to generate acid, which then deprotects the film-forming resin, converting it from being insoluble in the developer to being soluble in the developer. Chemically amplified photoresists include KrF photoresists (poly(p-hydroxystyrene) resin systems), ArF photoresists (poly(methacrylate) resin systems), and some EUV photoresists, which use a photoacid generator (PAG) as the photosensitive material.

[0005] Compared to KrF photoresist, the main resin of ArF photoresist contains no benzene rings and no phenolic hydroxyl groups. Therefore, electrons cannot transfer from the resin to the photoacid generator, and sensitized acid generation does not occur. Furthermore, the intensity of the ArF laser is relatively low, and the binding energy of the acid-sensitive groups commonly used in photoresists is relatively high. Therefore, the acid generation efficiency of the photoacid generator in ArF photoresist is lower than that of KrF. A photoacid generator with higher sensitivity, higher acidity, and higher acidity is required to achieve chemical amplification of ArF photoresist.

[0006] The acid generation efficiency, thermal stability, acid generation intensity, and transparency after photolysis of a photoacid generator (PAG) significantly influence the performance of photoresists. The diffusion length of the PAG directly determines the performance of photoresists and other key parameters, such as exposure energy, energy window, edge roughness, pattern topography, and mask error enhancement factor. An excellent PAG must achieve an optimal balance between solubility, stability, sensitivity, and process window.

[0007] Currently, when using ArF photoresists prepared with known photoacid generators such as TPS-PFBS for photolithography, there are common problems such as small depth of focus (DOF) and poor edge roughness. Summary of the Invention

[0008] To overcome the shortcomings of existing photoacid generators in photoresists, which often suffer from poor process window and edge roughness, the present invention provides a new photoacid generator. This new generator has a higher molecular weight, which reduces the diffusion of conventional photoacid generators during use, thereby improving the process window and edge roughness of the photoresist.

[0009] The technical solutions of the present invention are as follows:

[0010] The compound shown in the following formula I,

[0011]

[0012] Wherein, R1 is selected from C 1-12 Alkylene; R2 is selected from 5-20 membered heteroaryl or C 6-20 Aryl; X is halogen;

[0013] R3, R4 and R5 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;

[0014] a, b and c are the same or different and are independently selected from 0, 1, 2, 3, 4 or 5.

[0015] According to an embodiment of the present invention, R1 is selected from C 2-6 Alkylene; R2 is selected from 5-14 membered heteroaryl or C 6-14 Aryl; X is fluorine or chlorine;

[0016] R3, R4 and R5 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;

[0017] a, b and c are the same or different and are independently selected from 0, 1, 2 or 3.

[0018] According to an embodiment of the present invention, R1 is selected from C 2-4 Alkylene, such as ethylene, propylene or butylene; R2 is selected from thienyl, furyl, pyrrolyl; X is fluorine or chlorine;

[0019] R3, R4 and R5 are the same or different and are independently selected from methyl, ethyl, propyl, tert-butyl or cyclohexyl;

[0020] a, b and c are the same or different and are independently selected from 0, 1, 2 or 3.

[0021] According to an embodiment of the present invention, Formula I is selected from the structure shown in Formula IA below:

[0022]

[0023] wherein R1, R2 and X have the same meanings as above.

[0024] According to an embodiment of the present invention, Formula I is selected from the structure shown in the following Formula IB:

[0025]

[0026] wherein R1 and X have the above definitions; A is O, NH or S;

[0027] As an example, the compound represented by formula I is selected from the following structures:

[0028]

[0029]

[0030] The present invention also provides a method for preparing the compound represented by the above formula I, comprising the following steps:

[0031] The compound of formula 1-5 reacts with the compound of formula 1-6 to obtain the compound of formula I,

[0032]

[0033] wherein X, R1, R2, R3, R4, R5, a, b and c have the same meanings as above; and L is halogen or OH.

[0034] According to an embodiment of the present invention, L is chlorine.

[0035] According to an embodiment of the present invention, the compound of formula 1-5 is prepared by the following method:

[0036]

[0037] The compound of formula 1-3 reacts with the compound of formula 1-4 to obtain the compound of formula 1-5;

[0038] wherein X, R1, R3, R4, R5, a, b and c have the same meanings as above; L1 is halogen;

[0039] M is an alkali metal, such as sodium or potassium.

[0040] The present invention also provides the use of the compound represented by the above formula I as a photoacid generator.

[0041] The present invention also provides a photoresist composition, which comprises: a polymer resin and a photoacid generator; wherein the photoacid generator is a compound shown in the above formula I.

[0042] According to an embodiment of the present invention, the polymer resin is a polymer resin that can be subjected to ArF photolithography, for example, a polymethacrylate resin system.

[0043] In some embodiments of the present invention, the polymeric resin is selected from the structures shown below:

[0044]

[0045] 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, isopropyl alcohol, acetone, and gamma-butyrolactone.

[0046] 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 a triphenylsulfonium sulfonate salt system, for example, at least one selected from the following structures:

[0047]

[0048]

[0049] According to an embodiment of the present invention, the photoresist composition is a chemically amplified photoresist.

[0050] 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.

[0051] According to an embodiment of the present invention, the photoresist composition includes, in parts by mass: 50 to 200 parts of polymer resin, 1 to 30 parts of photoacid generator, 1 to 20 parts of photoacid diffusion inhibitor, and 1000 to 4000 parts of solvent.

[0052] According to an embodiment of the present invention, the photoresist composition includes, by mass, 80 to 120 parts of polymer resin, 10 to 15 parts of photoacid generator, 5 to 12 parts of photoacid diffusion inhibitor, and 2,000 to 3,500 parts of solvent.

[0053] The present invention also provides a photoresist coating, which comprises the photoresist composition described above.

[0054] The present invention also provides a method for preparing the photoresist coating, comprising: forming a film on a substrate by spin coating the photoresist composition to obtain a chemically amplified photoresist.

[0055] In some embodiments of the present invention, the substrate is a silicon wafer or the like.

[0056] The present invention also provides use of the above-mentioned photoresist coating in photolithography.

[0057] In some embodiments of the present invention, the photoresist coating is used for 193 nm photolithography.

[0058] Beneficial effects

[0059] The present invention overcomes the shortcomings of existing photoacid generators, such as poor photoresist process window and edge roughness, and provides a new photoacid generator. The photoacid generator of the present invention has a large molecular weight, which can reduce the diffusion of the photoacid generator during use, thereby improving the process window and edge roughness of the photoresist.

[0060] The preparation method of the photoacid generator of the present invention is simple, and a high-purity product can be obtained through a simple recrystallization step.

[0061] Compared with the existing photoacid generator for ArF lithography, the photoacid generator of the present invention significantly improves the edge roughness and DOF of the obtained photolithography pattern.

[0062] Terms and Definitions

[0063] The term "halogen" includes F, Cl, Br or I.

[0064] The term "C 1-12 "Alkylene" is understood to mean a straight-chain or branched saturated divalent hydrocarbon group having 1 to 12 carbon atoms. Preferably "C 1-6 Alkylene". "C 1-6“Alkylene” refers to straight-chain and branched divalent alkyl groups having 1, 2, 3, 4, 5, or 6 carbon atoms. Examples of the alkylene group include methylene, ethylene, propylene, butylene, pentylene, hexylene, isopropylene, isobutylene, sec-butylene, tert-butylene, isopentylene, 2-methylbutylene, 1-methylbutylene, 1-ethylpropylene, and 1,2-dimethylpropylene.

[0065] The term "C 1-12 "Alkyl" should be understood to mean a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably "C 1-6 Alkyl". "C 1-6 The 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, 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 isomers thereof.

[0066] The term "C 1-12 "Alkoxy" should be understood as -OC 1-12 Alkyl, where C 1-12 Alkyl has the above definition.

[0067] The term "C 3-20 "Cycloalkyl" should be understood to mean a saturated monovalent monocyclic, bicyclic hydrocarbon ring or polycyclic hydrocarbon ring (also called condensed hydrocarbon ring) having 3-20 carbon atoms. Bicyclic or polycyclic cycloalkyl groups include paracyclic cycloalkyl, bridged cycloalkyl and spirocyclic cycloalkyl; the paracyclic refers to a condensed ring structure formed by two or more cyclic structures sharing two adjacent ring atoms (i.e., sharing a bond). The bridged ring refers to a condensed ring structure formed by two or more cyclic structures sharing two non-adjacent ring atoms. The spirocyclic refers to a condensed ring structure formed by two or more cyclic structures sharing one ring atom. For example, the C 3-20 The cycloalkyl group may be C 3-8 Monocyclic cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, or C 7-12 Cycloalkyl, such as decahydronaphthalene ring; can also be C 7-12 Bridged ring cycloalkyl, such as norbornane, adamantane, bicyclo[2,2,2]octane.

[0068] The term "3-20 membered heterocyclyl" means a saturated or unsaturated monovalent monocyclic or bicyclic hydrocarbon ring containing 1-5 heteroatoms independently selected from N, O and S, preferably a "3-10 membered heterocyclyl". The term "3-10 membered heterocyclyl" means a saturated monovalent monocyclic or bicyclic hydrocarbon ring containing 1-5, preferably 1-3 heteroatoms selected from N, O and S. The heterocyclyl may be attached to the rest of the molecule through any one of the carbon atoms or the nitrogen atom (if present). In particular, the heterocyclyl may include, but is not limited to, a 4-membered ring such as azetidinyl, oxetanyl; a 5-membered ring such as tetrahydrofuranyl, dioxolyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, pyrrolinyl; or a 6-membered ring such as tetrahydropyranyl, piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl or trithianyl; or a 7-membered ring such as diazepanyl. Optionally, the heterocyclic group may be benzo-fused. The heterocyclic group may be bicyclic, for example, but not limited to, a 5,5-membered ring such as a hexahydrocyclopenta[c]pyrrole-2(1H)-yl ring, or a 5,6-membered bicyclic ring such as a hexahydropyrrolo[1,2-a]pyrazine-2(1H)-yl ring. The nitrogen-containing ring may be partially unsaturated, i.e., it may contain one, two, or more double bonds, such as, but not limited to, 2,5-dihydro-1H-pyrrolyl, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl, or 4H-[1,4]thiazinyl, or it may be benzo-fused, such as, but not limited to, dihydroisoquinolinyl, 1,3-benzoxazolyl, or 1,3-benzodioxolyl. According to the present invention, the heterocyclic group is non-aromatic.

[0069] The term "C 6-20 "Aryl" is understood to mean a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring having 6 to 20 carbon atoms, preferably "C 6-14 Aryl". The term "C 6-14 "Aryl" is understood to mean preferably a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring ("C 6-14 or a ring having 9 carbon atoms ("C9 aryl"), for example indanyl or indenyl, or a ring having 10 carbon atoms ("C 10 aryl) such as tetrahydronaphthyl, dihydronaphthyl or naphthyl, or a ring having 13 carbon atoms ("C 13 aryl), such as fluorenyl, or a ring having 14 carbon atoms ("C 14 aryl”), such as anthracenyl. When the C 6-20When the aryl group is substituted, it may be monosubstituted or polysubstituted. Furthermore, there is no limitation on the position of substitution, and for example, substitution may be at the ortho, para or meta position.

[0070] The term "5-20 membered heteroaryl" is understood to include monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5 to 20 ring atoms and containing 1 to 5 heteroatoms independently selected from N, O and S, for example "5-14 membered heteroaryl". The term "5-14 membered heteroaryl" is understood to include monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms, in particular 5 or 6 or 9 or 10 carbon atoms, and containing 1 to 5, preferably 1 to 3 heteroatoms independently selected from N, O and S and, in addition, in each case may be benzo-fused. In particular, the heteroaryl group is selected from thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl and the like and benzo derivatives thereof, such as benzofuranyl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl and the like; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl and the like and benzo derivatives thereof, such as quinolyl, quinazolinyl, isoquinolyl and the like; or acininyl, indolizinyl, purinyl and the like and benzo derivatives thereof; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 This is the photolithography result of the chemically amplified photoresist in Comparative Example 1.

[0072] Figure 2 This is the photolithography result using the chemically amplified photoresist in Example 1.

[0073] Figure 3 This is the photolithography result using the chemically amplified photoresist in Example 2.

[0074] Figure 4 This is the photolithography result using the chemically amplified photoresist in Example 3.

[0075] Figure 5 This is the photolithography result using the chemically amplified photoresist in Example 4. DETAILED DESCRIPTION

[0076] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0077] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0078] Synthesis Example 1

[0079] This embodiment provides a triphenylsulfonium salt-based photoacid generator, and the synthesis method of the photoacid generator is as follows:

[0080] (1) Synthesis of sodium 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfinate

[0081]

[0082] In a glass flask equipped with a thermometer and a condenser, 90.7 g of 4-bromo-3,3,4,4-tetrafluoro-1-butanol, 137.48 g of acetonitrile, 19.65 g of sodium bicarbonate, and 55.3 g of sodium dithionite (85% content) were added in sequence. Finally, 375 g of water was added dropwise under nitrogen protection.

[0083] After the dropwise addition was completed, the temperature was raised to 55°C and stirred for 5 hours.

[0084] After the reaction was terminated, the mixture was cooled to room temperature and the reaction solution was directly used for the next step of synthesis.

[0085] The NMR of the intermediate 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfinate sodium is 1 H NMR (D2O) δ (ppm): 3.87-3.78 (q, 2H), 2.39-2.24 (m, 2H).

[0086] 19 F NMR (D2O) δ (ppm): -112.22 (s, 2F), -130.93 (s, 2F).

[0087] (2) Synthesis of sodium 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonate

[0088]

[0089] The sodium 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfinate reaction solution obtained in step (1) was added dropwise with 49.26 g of hydrogen peroxide solution (30%) under ice bath conditions without further treatment. The temperature was controlled below 25°C.

[0090] After the addition was completed, stirring was continued for 2.5 hours at 25°C under nitrogen protection.

[0091] After the reaction was terminated, 338 g of acetonitrile and the aqueous solution were distilled off.

[0092] The NMR of the intermediate 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonate sodium is 19 F NMR (D2O) δ (ppm): -112.11 (s, 2F), -116.85 (s, 2F).

[0093] (3) Synthesis of 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid triphenylsulfonium salt

[0094]

[0095] The reaction solution containing sodium 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonate obtained after the treatment in step (2) above was directly added to 354.56 g of dichloromethane. An aqueous solution consisting of 75 g of triphenylsulfonium chloride and 168 g of water was then added dropwise. After the addition was complete, the mixture was stirred for 2 hours.

[0096] After the reaction was terminated, the organic layer of the reaction solution was separated into two layers.

[0097] The lower organic phase was collected and extracted five times with 230 g of water.

[0098] Filter by suction to remove insoluble matter and concentrate the organic phase.

[0099] Dry thoroughly without any moisture remaining.

[0100] The NMR of the intermediate 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid triphenylsulfonium salt is 1 H NMR (CDCl3) δ (ppm): 7.80-7.58 (m, 15H), 3.88-3.83 (q, 2H), 2.65-2.52 (m, 2H).

[0101] (4) Synthesis of 1,1,2,2-tetrafluoro-4-[(furan-2-carbonyl)oxy]butane-1-sulfonic acid triphenylsulfonium salt

[0102]

[0103] Into a glass flask equipped with a thermometer, a condenser, and a dropping funnel, 51.61 g of dried 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid triphenylsulfonium salt, 25.53 g of furoyl chloride, and 115.43 g of dichloromethane were added, followed by stirring.

[0104] 78.66 g of triethylamine was added dropwise thereto under ice bath conditions, and the temperature was controlled below 25°C.

[0105] After the addition was complete, the mixture was stirred at room temperature (25°C) for 12 hours.

[0106] 205 g of water was added to the reaction solution, and then the aqueous layer was removed and extracted and washed with water five times.

[0107] The insoluble matter was filtered off by suction, and the organic phase was then rotary evaporated at 60°C for 1 hour.

[0108] Weigh the rotary evaporated product and add 4 times the weight of dichloromethane. Also, prepare 5 times the weight of the dichloromethane solution in isopropyl ether. First, add seed crystals to the isopropyl ether, then drip the dichloromethane solution into the isopropyl ether. Precipitate twice.

[0109] The precipitate was filtered and dried.

[0110] The NMR of 1,1,2,2-tetrafluoro-4-[(furan-2-carbonyl)oxy]butane-1-sulfonic acid triphenylsulfonium salt is 1 HNMR (CDCl3) δ (ppm): 7.78-7.66 (m, 15H), 7.55 (s, 1H), 7.16-7.13 (t, 1H), 6.50-6.47 (m, 1H), 4.50-4.52 (q, 2H), 2.93-2.77 (m, 2H).

[0111] Synthesis Example 2

[0112] (1) Synthesis of 1,1,2,2-tetrafluoro-4-[(thiophene-2-carbonyl)oxy]butane-1-sulfonic acid triphenylsulfonium salt

[0113]

[0114] Into a glass flask equipped with a thermometer, a condenser, and a dropping funnel, 51.61 g of dried 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid triphenylsulfonium salt, 21.14 g of 2-thiophenecarbonyl chloride, and 115.43 g of dichloromethane were added, followed by stirring.

[0115] 78.66 g of triethylamine was added dropwise thereto under ice bath conditions, and the temperature was controlled below 25°C.

[0116] After the addition was complete, the mixture was stirred at room temperature (25°C) for 12 hours.

[0117] 205 g of water was added to the reaction solution, and then the aqueous layer was removed and extracted and washed with water five times.

[0118] The insoluble matter was filtered off by suction, and the organic phase was then rotary evaporated at 60°C for 1 hour.

[0119] Weigh the rotary evaporated product and add 4 times the weight of dichloromethane. Also, prepare 5 times the weight of the dichloromethane solution in isopropyl ether. First, add seed crystals to the isopropyl ether, then drip the dichloromethane solution into the isopropyl ether. Precipitate twice.

[0120] The precipitate was filtered and dried.

[0121] The NMR of 1,1,2,2-tetrafluoro-4-[(thiophene-2-carbonyl)oxy]butane-1-sulfonic acid triphenylsulfonium salt is 1 HNMR (CDCl3) δ (ppm): 7.78-7.65 (m, 16H), 7.55-7.52 (t, 1H), 7.08-7.05 (q, 1H), 4.58-4.51 (q, 2H), 2.92-2.78 (m, 2H).

[0122] Synthesis Example 3

[0123] (1) Synthesis of sodium 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfinate

[0124]

[0125] In a glass flask equipped with a thermometer and a condenser, 5 g of 5-bromo-4,4,5,5-tetrafluoro-1-pentanol (98% content), 7.35 g of acetonitrile, 1.04 g of sodium bicarbonate, and 2.93 g of sodium dithionite (85% content) were added in sequence. Finally, 26.6 g of water was added dropwise under nitrogen protection.

[0126] After the dropwise addition was completed, the temperature was raised to 55°C and stirred for 5 hours.

[0127] After the reaction was terminated, the mixture was cooled to room temperature and the reaction solution was directly used for the next step of synthesis.

[0128] The NMR of the intermediate 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfinate sodium is 19 F NMR (D2O) δ (ppm): -112.83 (s, 2F), -130.66 (s, 2F).

[0129] (2) Synthesis of sodium 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfonate

[0130]

[0131] The sodium 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfinate reaction solution obtained in step (1) was not treated. 2.61 g of hydrogen peroxide solution (30%) was added dropwise to the reaction solution under ice bath conditions. The temperature was controlled below 25°C.

[0132] After the addition was completed, stirring was continued for 2.5 hours at a reaction temperature of 25°C under nitrogen protection.

[0133] After the reaction was terminated, 8.5 g of acetonitrile and the aqueous solution were distilled off.

[0134] The NMR of the intermediate 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfonic acid sodium salt is 19 F NMR (D2O) δ (ppm): -112.64 (s, 2F), -116.34 (s, 2F).

[0135] (3) Synthesis of 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfonic acid triphenylsulfonium salt

[0136]

[0137] 18.78 g of dichloromethane solution was directly added to the sodium 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfonate reaction solution obtained after treatment in step (2). An aqueous solution consisting of 3.98 g of triphenylsulfonium chloride and 10 g of water was then added dropwise. After the addition was complete, the mixture was stirred for 2 hours.

[0138] After the reaction is completed, the mixture is allowed to stand and the liquid is separated.

[0139] The lower organic phase was collected and extracted five times with 15 g of water.

[0140] Filter by suction to remove insoluble matter and concentrate the organic phase.

[0141] Dry thoroughly without any moisture remaining.

[0142] The NMR of the intermediate 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid triphenylsulfonium salt is 1 H NMR (DMSO-d6) δ (ppm): 7.90-7.71 (m, 15H), 3.44-3.38 (q, 2H), 2.29-2.13 (m, 2H), 1.64-1.54 (m, 2H).

[0143] (4) Synthesis of 1,1,2,2-tetrafluoro-5-[(furan-2-carbonyl)oxy]pentane-1-sulfonic acid triphenylsulfonium salt

[0144]

[0145] Into a glass flask equipped with a thermometer, a condenser, and a dropping funnel, 8.46 g of dried 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfonic acid triphenylsulfonium salt, 3.13 g of furoyl chloride, and 52.34 g of dichloromethane were added, followed by stirring.

[0146] 12.54 g of triethylamine was added dropwise thereto under ice bath conditions, and the temperature was controlled below 25°C.

[0147] After the dropwise addition was completed, the mixture was stirred at room temperature for 12 hours at a reaction temperature of 25°C.

[0148] 30 g of water was added to the reaction solution, and then the aqueous layer was removed and extracted and washed with water for 5 times.

[0149] The insoluble matter was filtered off by suction, and the organic phase was then rotary evaporated at 60°C for 1 hour.

[0150] Weigh the rotary evaporated product and add 4 times the weight of dichloromethane. Also, prepare 5 times the weight of the dichloromethane solution in isopropyl ether. First, add seed crystals to the isopropyl ether, then drip the dichloromethane solution into the isopropyl ether. Precipitate twice.

[0151] The precipitate was filtered and dried.

[0152] The NMR of 1,1,2,2-tetrafluoro-5-[(furan-2-carbonyl)oxy]pentane-1-sulfonic acid triphenylsulfonium salt is 1 HNMR (CDCl3) δ (ppm): 7.78-7.65 (m, 15H), 7.56-7.54 (s, 1H), 7.18-7.14 (t, 1H) ), 6.50-6.47(m, 1H), 4.34-4.27(q, 2H), 2.58-2.40(m, 2H), 2.09-2.00(m, 2H).

[0153] Synthesis Example 4

[0154] (1) Synthesis of 1,1,2,2-tetrafluoro-5-[(thiophene-2-carbonyl)oxy]pentane-1-sulfonic acid triphenylsulfonium salt

[0155]

[0156] Into a glass flask equipped with a thermometer, a condenser, and a dropping funnel, 8.46 g of dried 1,1,2,2-tetrafluoro-5-hydroxypentane-1-sulfonic acid triphenylsulfonium salt, 3.51 g of 2-thiophenecarbonyl chloride, and 52.34 g of dichloromethane were added, followed by stirring.

[0157] 12.54 g of triethylamine was added dropwise thereto under ice bath conditions, and the temperature was controlled below 25°C.

[0158] After the dropwise addition was completed, the mixture was stirred at room temperature for 12 hours at a reaction temperature of 25°C.

[0159] 30 g of water was added to the reaction solution, and then the aqueous layer was removed and extracted and washed with water for 5 times.

[0160] The insoluble matter was filtered off by suction, and the organic phase was then rotary evaporated at 60°C for 1 hour.

[0161] Weigh the rotary evaporated product and add 4 times the weight of dichloromethane. Also, prepare 5 times the weight of the dichloromethane solution in isopropyl ether. First, add seed crystals to the isopropyl ether, then drip the dichloromethane solution into the isopropyl ether. Precipitate twice.

[0162] The precipitate was filtered and dried.

[0163] The NMR of 1,1,2,2-tetrafluoro-5-[(thiophene-2-carbonyl)oxy]pentane-1-sulfonic acid triphenylsulfonium salt is 1 HNMR (CDCl3) δ (ppm): 7.80-7.64 (m, 16H), 7.55-7.51 (t, 1H), 7.09-7.04 (q, 1H), 4.33-4.26 (q, 2H), 2.57-2.42 (m, 2H), 2.09-2.00 (m, 2H).

[0164] The following is an example of a photoresist formulation

[0165] Polymer resin P1

[0166]

[0167] Preparation of Polymer Resin P1: In a nitrogen-protected four-necked flask equipped with a stirrer and condenser, pre-charge butanone (120 g) and heat to reflux. Slowly add 2-carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate (150 g), 1-(1-methylethyl)cyclopentyl methacrylate (115.3 g), initiator AIBN (9.436 g), nDT (12 g), and a solvent mixture over a 4-hour period. Continue stirring for 3 hours after the addition is complete. Once polymerization is complete, cool the reaction system to room temperature.

[0168] The system was added to n-heptane (1500 g), and the white solid powder was collected and dried in a vacuum oven at 45° C. for 24 hours to obtain copolymer P1 (179.9 g, weight-average molecular weight 8516, molecular weight distribution coefficient 1.84).

[0169] The photoacid generator in Application Examples 1-4 and Comparative Example 1 is selected from the following structures:

[0170]

[0171] The photoacid diffusion inhibitors in Application Examples 1-4 and Comparative Example 1 are selected from the following structures:

[0172]

[0173] Table 1 Photoresist components (mass ratio)

[0174]

[0175] Comparative Example 1

[0176] A chemically amplified photoresist comprising the following components in parts by weight:

[0177]

[0178] The preparation method of the chemically amplified photoresist is as follows: add each component according to the formula and stir until completely dissolved. The prepared chemically amplified photoresist is used as follows:

[0179] The chemically amplified photoresist was spin-coated on a 4-inch silicon wafer at a spin-coating speed of 1800 rpm. The film thickness of the chemically amplified photoresist was 800 Å. The wafer was pre-baked at 90°C for 60 seconds. The wafer was exposed in an ArF exposure machine with an exposure energy setting of 15-50 mj / cm 2 After exposure, post-bake at 90°C for 60 seconds; after the wafer cools to room temperature, develop with 2.38% TMAH developer for 30 seconds, and finally rinse with deionized water for 30 seconds to form the required photoresist pattern. Figure 1 shown.

[0180] Application Example 1

[0181] Compared with Comparative Example 1, the difference is that the photoacid generator B1 is replaced by B2, the feeding amount is the same, and the preparation method and use method are the same as those of Comparative Example 1. The specific data are shown in Table 1. Figure 2 shown.

[0182] Application Example 2

[0183] Compared with Comparative Example 1, the difference is that the photoacid generator B1 is replaced by B3, the feeding amount is the same, and the preparation method and use method are the same as those of Comparative Example 1. The specific data are shown in Table 1. Figure 3 shown.

[0184] Application Example 3

[0185] Compared with Comparative Example 1, the difference is that the photoacid generator B1 is replaced by B4, the feeding amount is the same, and the preparation method and use method are the same as those of Comparative Example 1. The specific data are shown in Table 1. Figure 4shown.

[0186] Application Example 4

[0187] Compared with Comparative Example 1, the difference is that the photoacid generator B1 is replaced by B5, the feeding amount is the same, and the preparation method and use method are the same as those of Comparative Example 1. The specific data are shown in Table 1. Figure 5 shown.

[0188] The detailed test performance results of Comparative Example 1 and Application Examples 1-4 are shown in Table 2.

[0189] Table 2

[0190] photoresist DOF Edge roughness Comparative Example 1 0.08μm 10.7 Application Example 1 0.1μm 6.64 Application Example 2 0.14μm 6.6 Application Example 3 0.12μm 6.4 Application Example 4 0.14μm 6.54

[0191] The data obtained by exposure lithography using a photolithography machine (Table 2) show that, compared with Comparative Example 1, after using the photoacid generator prepared by the present invention, the edge roughness and DOF of the photoresist are significantly improved, and the lithography effect is significantly better.

[0192] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A compound of formula I, I in, R1 is selected from C 1-12 Alkylene; R2 is selected from thienyl or furyl; X is fluorine; R3, R4 and R5 are the same or different and are independently selected from C 1-12 Alkyl, C 1-12 alkoxy; a, b and c are the same or different and are independently selected from 0, 1, 2 or 3.

2. The compound according to claim 1, wherein R1 is selected from C 2-6 Alkylene; R3, R4 and R5 are the same or different and are independently selected from C 1-6 Alkyl, C 1-6 Alkoxy; a, b and c are the same or different and are independently selected from 0 or 1.

3. The compound according to claim 1, wherein R1 is selected from C 2-4 Alkylene.

4. The compound according to any one of claims 1 to 3, wherein Formula I is selected from the structure shown in Formula IA below: IA wherein R1, R2 and X have the definitions as described in any one of claims 1-3.

5. The compound according to any one of claims 1 to 3, wherein Formula I is selected from the structure shown in Formula IB below: ONE wherein R1 and X have the definitions described in any one of claims 1 to 3; and A is O or S.

6. The compound according to any one of claims 1 to 3, wherein The compound represented by formula I is selected from the following structures: 。 7. A method for preparing the compound according to any one of claims 1 to 6, wherein: The steps include: The compound of formula 1-5 reacts with the compound of formula 1-6 to obtain the compound of formula I, ； wherein X, R1, R2, R3, R4, R5, a, b and c have the definitions as described in any one of claims 1 to 6; L is halogen or OH.

8. Use of the compound according to any one of claims 1 to 6 as a photoacid generator.

9. A photoresist composition comprising: A polymer resin and a photoacid generator; wherein the photoacid generator is the compound represented by formula I according to any one of claims 1 to 6. 10 . The photoresist composition according to claim 9 , wherein the polymer resin is a polymer resin for ArF lithography. The photoresist composition according to claim 10 , wherein the polymer resin is a polymethacrylate resin system.

12. The photoresist composition according to claim 9, wherein The photoresist composition also 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-amyl ketone, methyl isoamyl ketone, cyclopentanone, ethanol, acetonitrile, isopropanol, acetone, and γ-butyrolactone.

13. The photoresist composition according to claim 9, wherein The photoresist composition further includes a photoacid diffusion inhibitor; The photoacid diffusion inhibitor is selected from at least one of the structures shown below: 。 14. The photoresist composition according to any one of claims 9 to 13, wherein The photoresist composition comprises: a polymer resin, a photoacid generator, a photoacid diffusion inhibitor and a solvent.

15. A photoresist coating comprising the photoresist composition according to any one of claims 9 to 14.

16. The method for preparing the photoresist coating according to claim 15, wherein: include, The photoresist composition according to any one of claims 9 to 14 is spin-coated on a substrate to form a film to obtain a chemically amplified photoresist. The photoresist coating according to claim 15 is used for 193 nm photolithography.

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