Sulfonium sulfonate photoacid generator as well as synthesis method and application thereof

Abstract

The invention relates to a sulfonium sulfonate photoacid generator as shown in a formula I, a synthesis method of the sulfonium sulfonate photoacid generator and a photoresist composition containing the sulfonium sulfonate photoacid generator. The photoacid generator provided by the invention has relatively large molecular weight, can reduce the diffusion of the photoacid generator in the use process, and is beneficial to improving the process window and edge roughness of photoresist. In addition, the preparation method of the photoacid generator is simple, and a high-purity product can be obtained through a simple recrystallization step. Moreover, compared with the existing photoacid generator for ArF photoetching, the photoacid generator disclosed by the invention has the advantage that the edge roughness and DOF of the obtained photoetching pattern are remarkably improved. # imgabs0 #

Description

Technical Field

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

[0002] Photoresist is a crucial core material in the photolithography process. It is also called photoresist. It refers to an etch-resistant material whose solubility changes after being irradiated or radiated by electromagnetic waves such as ultraviolet light, X-rays or electron beams. It plays the role of transferring patterns and can be widely used in fine graphics processing fields such as displays, integrated circuits, micro-electromechanical systems (MEMS) and optoelectronic devices. In recent years, the rapid development of large-scale integrated circuits and display industries has put forward higher requirements for photolithography technology: to obtain more refined and higher-resolution replica patterns.

[0003] After semiconductor integrated circuit lithography technology began to use deep ultraviolet (DUV) light sources, chemical amplification (CAR) technology gradually became the mainstream of industry applications. In chemical amplification photoresist technology, the resin is polyethylene that is protected by chemical groups and is therefore difficult to dissolve. Therefore, chemical amplification photoresists require the use of photoacid generators (PAGs) as photoinitiators. When the photoresist is exposed, the photoacid generator (PAG) in the exposed area will produce an acid. This acid acts as a catalyst during the post-heat baking process, which will remove the protective groups of the resin and make the resin easy to dissolve. The exposure speed of chemical amplification photoresist is 10 times that of diazonaphthoquinone (DNQ) photoresist, and it has good optical sensitivity to deep ultraviolet light sources, as well as high contrast and high resolution.

[0004] Chemically amplified photoresists generally include four main components: film-forming resin, photoacid generator, additives and solvent. Its mechanism of action is that the photoacid generator absorbs light to generate acid, and the acid causes the film-forming resin to undergo a deprotection reaction, and the resin changes from being insoluble in the developer to being soluble in the developer. Chemically amplified photoresists include KrF photoresists (polyparahydroxystyrene resin system) and ArF photoresists (polymethacrylate resin system) as well as some EUV photoresists, which use photoacid generators (PAGs) as photosensitive materials.

[0005] Compared with KrF photoresist, the main resin of ArF photoresist does not contain benzene rings and phenolic hydroxyl groups, so electrons cannot be transferred from the resin to the photoacid generator, and there is no sensitized acid generation. In addition, the intensity of ArF laser is relatively low and the binding energy of acid-sensitive groups commonly used in photoresists is high. Therefore, in ArF photoresists, the acid generation efficiency of photoacid generators is lower than that of KrF, and photoacid generators with higher sensitivity, acid generation efficiency and stronger acidity are required to achieve chemical amplification of ArF photoresists.

[0006] The acid generation efficiency, thermal stability, acid generation intensity and transparency after photolysis of the photoacid generator have a great influence on the performance of the photoresist. The diffusion length of the photoacid generator directly determines the performance of the photoresist and some important parameters, such as exposure energy, energy window, edge roughness, pattern morphology and mask error enhancement factor. An excellent photoacid generator should achieve an optimal balance between solubility, stability, sensitivity and process window.

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

[0008] In order to overcome the shortcomings of poor process window and edge roughness of photoresist prepared by existing photoacid generators, the present invention provides a new photoacid generator, which has a large molecular weight, can reduce the diffusion of conventional photoacid generators during use, and is conducive to improving the process window and edge roughness of photoresist.

[0009] The technical solution of the present invention is 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, furanyl, 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 shown in 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 are as defined 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 are as defined 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 shown in 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 as 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 polymer resin is selected from the structure 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, isopropanol, acetone, and γ-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, selected from at least one of the structures shown below:

[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, 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.

[0052] 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.

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

[0054] The 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 the use of the photoresist coating as described above in photolithography.

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

[0058] Beneficial Effects

[0059] The invention overcomes the shortcomings of the existing photoacid generators in that the process window and edge roughness of the photoresist are poor, and provides a new photoacid generator. The photoacid generator of the invention has a large molecular weight, which can reduce the diffusion of the photoacid generator during use, and is beneficial to 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" means a straight chain and branched divalent alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkylene group is, for example, methylene, ethylene, propylene, butylene, pentylene, hexylene, isopropylene, isobutylene, sec-butylene, tert-butylene, isopentylene, 2-methylbutylene, 1-methylbutylene, 1-ethylpropylene, 1,2-dimethylpropylene, and the like.

[0065] 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 1-6 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, 1,2-dimethylbutyl, or the like or isomers thereof.

[0066] The term "C 1-12 "Alkoxy" is understood to mean -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 one 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; it 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 connected 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, such as, 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 ring containing nitrogen atoms 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, dihydroisoquinolyl, 1,3-benzoxazolyl, 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 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. Also, there is no limitation on the substitution position, for example, it may be substituted at the ortho position, para position 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, furanyl, 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 azinyl, 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 lithography result of the chemically amplified photoresist in Comparative Example 1.

[0072] Figure 2 The photolithography results of the chemically amplified photoresist in Example 1 are shown.

[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 The photolithography results using the chemically amplified photoresist in Example 4 are shown. DETAILED DESCRIPTION

[0076] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions 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 included in the scope 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 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 (content 85%) were added in sequence, and 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 is terminated, the mixture is cooled to room temperature and the reaction solution is 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 the above step (1) was not treated, and 49.26 g of hydrogen peroxide solution (concentration 30%) was directly added dropwise thereto under ice bath conditions. 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 is directly added to 354.56 g of dichloromethane. Then, an aqueous solution formed by 75 g of triphenylsulfonium chloride and 168 g of water is added dropwise thereto. After the addition is completed, the mixture is 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, 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] In 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 completed, 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 water layer was removed and extracted and washed with water for 5 times.

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

[0108] Weigh the product after rotary evaporation, add 4 times the weight of dichloromethane to the product. At the same time, prepare 5 times the weight of dichloromethane solution. First add seed crystals to the dichloromethane solution, then drop the dichloromethane solution into the dichloromethane solution. 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] In 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 completed, 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 water layer was removed and extracted and washed with water for 5 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 product after rotary evaporation, add 4 times the weight of dichloromethane to the product. At the same time, prepare 5 times the weight of dichloromethane solution. First add seed crystals to the dichloromethane solution, then drop the dichloromethane solution into the dichloromethane solution. 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 (content 98%), 7.35 g of acetonitrile, 1.04 g of sodium bicarbonate, and 2.93 g of sodium dithionite (content 85%) 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 is terminated, the mixture is cooled to room temperature and the reaction solution is 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 the above step (1) was not treated, and 2.61 g of hydrogen peroxide solution (concentration 30%) was directly 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-sulfonate sodium 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 the treatment in step (2). Then, an aqueous solution formed by 3.98 g of triphenylsulfonium chloride and 10 g of water was added dropwise thereto. After the addition was completed, 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, 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] In 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 water 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 product after rotary evaporation, add 4 times the weight of dichloromethane to the product. At the same time, prepare 5 times the weight of dichloromethane solution. First add seed crystals to the dichloromethane solution, then drop the dichloromethane solution into the dichloromethane solution. 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] In 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 water 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 product after rotary evaporation, add 4 times the weight of dichloromethane to the product. At the same time, prepare 5 times the weight of dichloromethane solution. First add seed crystals to the dichloromethane solution, then drop the dichloromethane solution into the dichloromethane solution. Precipitate twice.

[0162] The precipitate was filtered off 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 steps of polymer resin P1: In a nitrogen-protected four-necked flask equipped with a stirrer and a condenser, butanone (120 g) was added in advance and heated to reflux. 2-Carbonyl-tetrahydrofuran-3-hydroxy-methylacrylate (150 g), 1-(1-methylethyl)cyclopentyl isomethacrylate (115.3 g), initiator AIBN (9.436 g), nDT (12 g) and a solvent mixed solution were slowly added thereto, and the addition time was controlled within 4 hours. After the dropwise addition was completed, stirring was continued for 3 hours. After the polymerization was completed, the reaction system was cooled to room temperature.

[0168] The system was added into 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 inhibitor in Application Examples 1-4 and Comparative Example 1 is 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 it is 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 coating 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 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 photolithography 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 feed 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 feed 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 feed 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 feed 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] It can be seen from the data obtained by performing exposure lithography with a photolithography machine (Table 2) 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 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. A compound of formula I, in, R1 is selected from C 1-12 Alkylene; R2 is selected from 5-20 membered heteroaryl or C 6-20 Aryl; X is halogen; 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; a, b and c are the same or different and are independently selected from 0, 1, 2, 3, 4 or 5.

2. The compound according to claim 1, wherein 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; 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; a, b and c are the same or different and are independently selected from 0, 1, 2 or 3.

3. The compound according to claim 1 or 2, wherein R1 is selected from C 2-4 Alkylene, such as ethylene, propylene or butylene; R2 is selected from thienyl, furanyl, pyrrolyl; X is fluorine or chlorine; R3, R4 and R5 are the same or different and are independently selected from methyl, ethyl, propyl, tert-butyl or cyclohexyl; a, b and c are the same or different and are independently selected from 0, 1, 2 or 3.

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: 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 4, wherein Formula I is selected from the structure shown in Formula IB below: wherein R1 and X have the definitions as described in any one of claims 1 to 4; and A is O, NH or S.

6. The compound according to any one of claims 1 to 5, 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 meanings 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, a photoacid generator; wherein the photoacid generator is a compound of formula I according to any one of claims 1 to 6; Preferably, the polymer resin is a polymer resin that can be subjected to ArF lithography, such as a polymethacrylate resin system; Preferably, 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, γ-butyrolactone; Preferably, the photoresist composition further comprises a photoacid diffusion inhibitor; Preferably, 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: Preferably, the photoresist composition is a chemically amplified photoresist; Preferably, the photoresist composition comprises: a polymer resin, a photoacid generator, a photoacid diffusion inhibitor and a solvent.

10. A photoresist coating comprising the photoresist composition according to claim 9; Preferably, the method for preparing the photoresist coating comprises: forming a film by spin coating the photoresist composition according to claim 9 on a substrate to obtain a chemically amplified photoresist; Preferably, the photoresist coating is used for 193 nm lithography.

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