A method for preparing a photoacid generator sulfonate for arf photoresist

Abstract

The application provides a preparation method of a photo-acid generator sulfonate for ARF photoresist, and belongs to the technical field of organic synthesis. The application uses 2-bromo-2,2-difluoroacetate as a reaction raw material, and is low in cost. The application improves an existing sulfinylation process, specifically, the application uses triphenylmethyl mercaptan as a raw material to introduce a-S- group, and through subsequent hydrogen peroxide oxidation, a sulfonate with high stability is obtained, and the reaction is easy to monitor. Moreover, the application introduces the-S- group first and then introduces an ester group, and in the subsequent deprotection and acylation reaction, heating in an alkaline environment is not needed, and the hydrolysis reaction of the ester group can be avoided.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to a method for preparing a sulfonate salt of photoacid-generating agent for ARF photoresist. Background Technology

[0002] ARF photoresist is a special resin material that reacts sensitively to light or other forms of radiation. During photolithography, when the photoresist is exposed to light or electron beams of specific wavelengths, its properties change significantly, such as changing from soluble to insoluble or vice versa. This change in properties allows the photoresist to be used to create micron- or nanometer-scale patterns, playing a crucial role in the fabrication of integrated circuits or other micro / nanostructures.

[0003] Photoacid generators are a key component of photoresist. When exposed to light, these photoacid generators decompose to produce acids. During post-exposure baking (PEB), these acids act as catalysts, causing chemical changes in the polymer within the photoresist, such as detaching unstable acid groups suspended on the polymer, thereby altering its solubility. In this way, the photoresist can create a significant difference in solubility between exposed and unexposed areas, thus enabling precise pattern transfer.

[0004] With the rapid miniaturization of pattern regularity, there is a trend towards shorter wavelengths of exposure light sources. For example, by shortening the wavelength from mercury lamp i-rays (365 nm) to krypton fluoride stimulated excimer lasers (248 nm), it is possible to mass-produce 64 M-bit (processing size below 0.25 μm) dynamic random access memory. To further realize the fabrication of DRAMs with integration densities of 256 M and 1 G or higher, argon fluoride (193 nm) lithography has been studied, and research is underway on devices for 65 nm nodes using lenses with high numerical apertures (≥0.9). In the subsequent fabrication of 45 nm node devices, fluorine gas lasers with a wavelength of 157 nm can be considered as an alternative, but their application has been delayed due to numerous problems, including increased scanner costs, changes in optical systems, and low etch resistance of resists. Argon fluoride immersion lithography has been proposed as an alternative to fluorine gas lithography, and its early applications are currently under development.

[0005] Chemically amplified photoresist materials (photoacid generators) suitable for this exposure wavelength have received widespread attention, and well-known examples include iodonium sulfonate, matte sulfonate, sulfonium sulfonate, and sulfonates.

[0006] Patent CN101687781 provides a method for preparing the fluorosulfonic acid compound with the structure shown in formula (A) and the sulfonate with the structure shown in formula (B). The synthetic route is as follows:

[0007]

[0008] This method has the following problems:

[0009] 1. The starting material, 1,1-difluorobromoethanol, is extremely expensive.

[0010] 2. Sodium dithionite used in intermediates 2 and 3 is prone to deterioration and difficult to detect.

[0011] 3. In the absence of fluorescence absorption at R1, intermediates 2, 3, and 4 are difficult to monitor, increasing the difficulty of synthesis.

[0012] 4. Steps 2 and 3 of the intermediate need to be heated in an alkaline aqueous phase, which can easily cause hydrolysis of the ester group. Summary of the Invention

[0013] In view of this, the purpose of this invention is to provide a method for preparing a photoacid-generating agent sulfonate for ARF photoresist. The preparation method provided by this invention is low in cost, easy to monitor, and the reaction process is stable.

[0014] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0015] This invention provides a method for preparing a photoacid-generating sulfonate for ARF photoresists, wherein the photoacid-generating sulfonate has the structure shown in Formula I:

[0016]

[0017] In formula I, R 1 The following groups are represented: substituted or unsubstituted alkyl groups with 1 to 10 carbon atoms; substituted or unsubstituted alkenyl groups with 1 to 10 carbon atoms having at least a double bond at the end; substituted or unsubstituted alicyclic organic groups with 3 to 20 carbon atoms; substituted or unsubstituted aryl groups with 6 to 20 carbon atoms; substituted or unsubstituted alkoxy groups with 1 to 10 carbon atoms; substituted or unsubstituted aryloxy groups with 6 to 20 carbon atoms; substituted or unsubstituted alkyl carbonyl groups with 2 to 10 carbon atoms; substituted or unsubstituted aryl carbonyl groups with 7 to 20 carbon atoms; substituted or unsubstituted alkyl carbonyl groups with 2 to 10 carbon atoms; substituted or unsubstituted aryl carbonyl groups with 7 to 20 carbon atoms; substituted or unsubstituted alkoxy carbonyl groups with 1 to 10 carbon atoms; or substituted or unsubstituted aryloxy carbonyl groups with 7 to 20 carbon atoms.

[0018] Q + It is a munonium ion;

[0019] The preparation method includes the following steps:

[0020] 2-Bromo-2,2-difluoroacetate, sodium borohydride, and an organic solvent were mixed and subjected to a reduction reaction to obtain 2-bromo-2,2-difluoroethanol.

[0021] The 2-bromo-2,2-difluoroethanol, triphenylmethylthiol, base and organic solvent were mixed and subjected to a substitution reaction to obtain a compound having the structure shown in formula a.

[0022]

[0023] A compound having the structure shown in formula a undergoes an acylation reaction with an acyl chloride compound having the structure shown in formula b to obtain a compound having the structure shown in formula c.

[0024]

[0025] A compound having the structure shown in formula c undergoes a deprotection reaction with trifluoroacetic acid to give a compound having the structure shown in formula d.

[0026]

[0027] A compound having the structure shown in formula d, hydrogen peroxide, and an organic solvent are mixed and subjected to an oxidation reaction to obtain a compound having the structure shown in formula e.

[0028]

[0029] A compound having the structure shown in Formula e undergoes an ion exchange reaction with a monovalent onium salt to obtain a photoacid-producing sulfonate having the structure shown in Formula I.

[0030] Preferably, the R 1 It is a 1-adamantyl group, a substituted or unsubstituted aryl group with 6 to 20 carbon atoms, or a substituted or unsubstituted alkyl group with 1 to 7 carbon atoms.

[0031] Preferably, the 2-bromo-2,2-difluoroacetate is methyl 2-bromo-2,2-difluoroacetate or ethyl 2-bromo-2,2-difluoroacetate;

[0032] The reduction reaction occurs at a temperature of 0–70°C.

[0033] Preferably, triphenylmethyl mercaptan is replaced with tert-butyl mercaptan.

[0034] Preferably, the alkali is one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, ammonia, ammonia in methanol, ammonium bicarbonate, sodium thiosulfate, sodium bicarbonate, triethylamine, diisopropylethylamine, pyridine, n-butyllithium, isobutyllithium, tert-butyllithium, diisopropylaminolithium, bis(trimethylsilyl)aminolithium, sodium bis(trimethylsilyl)amino, potassium bis(trimethylsilyl)amino, imidazole, sodium methoxide, sodium ethoxide, sodium amino, potassium trimethylsilanolate, and tetramethylethylenediamine.

[0035] The substitution reaction is carried out at a temperature of 0–80°C for 2–3 hours.

[0036] Preferably, the acyl chloride compound having the structure shown in Formula b is 1-adamantaneformyl chloride, arylformyl chloride, substituted arylformyl chloride, or C1-C7 alkyl acyl chloride.

[0037] Preferably, the acylation reaction is carried out at a temperature of 25–30°C for 2–3 hours.

[0038] The deprotection reaction is carried out at a temperature of 25–30°C for 12–16 hours.

[0039] Preferably, the oxidation reaction is carried out at a temperature of ≤20°C for 12 to 16 hours.

[0040] Preferably, the structural formula of the monovalent onium salt is Q. + X - X - It can be a halide ion, an alkyl sulfonate ion, or an aryl sulfonate ion.

[0041] Preferably, the ion exchange reaction is carried out at a temperature of 25–30°C for 12–16 hours.

[0042] This invention provides a method for preparing a sulfonate salt, a photoacid-generating agent for ARF photoresists. The method uses 2-bromo-2,2-difluoroacetate as a reactant, resulting in low cost. Specifically, this invention improves upon existing sulfination processes by introducing a -S- group using triphenylmethylthiol as a raw material. Subsequent oxidation with hydrogen peroxide yields a highly stable sulfonate salt. Due to the introduction of an aryl group, which absorbs some ultraviolet light under UV irradiation, the aryl group can be detected by a UV detector, facilitating monitoring during the reaction. Furthermore, this invention introduces the -S- group before the ester group, eliminating the need for heating in an alkaline environment during subsequent deprotection and acylation reactions, thus avoiding the hydrolysis of the ester group. Attached Figure Description

[0043] Figure 1 This is the synthetic route for the photoacid-producing sulfonate of the present invention;

[0044] Figure 2The 1-F NMR spectrum of (4'-methylphenyl)diphenylthio-1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonate obtained in Example 1;

[0045] Figure 3 The 1-H NMR spectrum of (4'-methylphenyl)diphenylthio-1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonate obtained in Example 1;

[0046] Figure 4 The high performance liquid chromatogram of (4'-methylphenyl)diphenylthio-1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonate obtained in Example 1;

[0047] Figure 5 The 1-F NMR spectrum of triphenylthio-4'-dimethylaminobenzoic acid-2,2-difluoro-2-sulfonyl ethyl ester sulfonate obtained in Example 2;

[0048] Figure 6 The 1-H NMR spectrum of triphenylthio-4'-dimethylaminobenzoic acid-2,2-difluoro-2-sulfonyl ethyl ester sulfonate obtained in Example 2;

[0049] Figure 7 The high-performance liquid chromatogram of triphenylthio-4'-dimethylaminobenzoic acid-2,2-difluoro-2-sulfonyl ethyl ester sulfonate obtained in Example 2 is shown. Detailed Implementation

[0050] This invention provides a method for preparing a photoacid-generating sulfonate for ARF photoresists, wherein the photoacid-generating sulfonate has the structure shown in Formula I:

[0051]

[0052] In formula I, R 1 The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, wherein the alkyl group is a straight-chain or straight-chain alkyl group; preferably, some or all of the hydrogen atoms of the alkyl group are optionally substituted with fluorine or hydroxyl groups, or, the two hydrogen atoms on the same carbon atom constituting the alkyl group are optionally substituted with an oxygen atom to form a ketone group;

[0053] Or, R 1 The alkenyl group is a substituted or unsubstituted alkenyl group having at least a double bond at the end, having 1 to 10 carbon atoms, and the alkenyl group is a straight-chain or branched alkenyl group; preferably, some or all of the hydrogen atoms of the terminal alkenyl group are optionally substituted with fluorine or hydroxyl, or the two hydrogen atoms on the same carbon atom constituting the terminal alkenyl group are optionally substituted with an oxygen atom to form a ketone group.

[0054] Or, R 1The alicyclic organic group represents a substituted or unsubstituted alicyclic organic group with 3 to 20 carbon atoms. Preferably, some or all of the hydrogen atoms of the alicyclic organic group are optionally substituted with fluorine or hydroxyl groups, or the two hydrogen atoms on the same carbon atom constituting the alicyclic organic group are optionally substituted with one oxygen atom to form a ketone group.

[0055] Or, R 1 The aryl group represents a substituted or unsubstituted aryl group with 6 to 20 carbon atoms, preferably benzene, anthracene, phenanthrene or naphthalene, and preferably, some or all of the hydrogen atoms of the aryl group are substituted by fluorine or hydroxyl groups;

[0056] Or, R 1 The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, wherein the alkoxy group is a straight-chain alkoxy group or a branched-chain alkoxy group; preferably, some or all of the hydrogen atoms of the alkoxy group are optionally substituted with fluorine or hydroxyl groups;

[0057] Or, R 1 The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, preferably wherein some or all of the hydrogen atoms of the aryloxy group are optionally substituted with fluorine or hydroxyl groups;

[0058] Or, R 1 The alkyl carbonyl group represents a substituted or unsubstituted alkyl carbonyl group having 2 to 10 carbon atoms, wherein the alkyl carbonyl group is a straight-chain alkyl carbonyl group or a branched alkyl carbonyl group; preferably, some or all of the hydrogen atoms of the alkyl carbonyl group are optionally substituted with fluorine or hydroxyl groups;

[0059] Or, R 1 The aryl carbonyl group represents a substituted or unsubstituted aryl carbonyl group with 7 to 20 carbon atoms. Preferably, some or all of the hydrogen atoms of the aryl carbonyl group are optionally substituted with fluorine or hydroxyl groups.

[0060] Or, R 1 The alkyl carbonyl group represents a substituted or unsubstituted alkyl carbonyl group having 2 to 10 carbon atoms, wherein the alkyl carbonyl group is straight-chain or branched; preferably, some or all of the hydrogen atoms of the alkyl carbonyl group are optionally substituted with fluorine or hydroxyl groups;

[0061] Or, R 1 The aryl carbonyl group represents a substituted or unsubstituted aryl carbonyl group having 7 to 20 carbon atoms. Preferably, some or all of the hydrogen atoms of the aryl carbonyl group are optionally substituted with fluorine or hydroxyl groups.

[0062] Or, R 1 The alkoxycarbonyl group represents a substituted or unsubstituted alkoxycarbonyl group having 1 to 10 carbon atoms, wherein the alkoxycarbonyl group is straight-chain or branched; preferably, some or all of the hydrogen atoms of the alkoxycarbonyl group are optionally substituted with fluorine or hydroxyl groups.

[0063] Or, R 1The aryloxycarbonyl group represents a substituted or unsubstituted aryloxycarbonyl group with 7 to 20 carbon atoms. Preferably, some or all of the hydrogen atoms of the aryloxycarbonyl group are optionally substituted with fluorine or hydroxyl groups.

[0064] In this invention, the R 1 Preferably, it is a 1-adamantyl group, a substituted or unsubstituted aryl group with 6 to 20 carbon atoms, or a substituted or unsubstituted alkyl group with 1 to 7 carbon atoms.

[0065] In this invention, the R 1 Preferably, it is a 1-adamantyl group, a substituted or unsubstituted aryl group with 6 to 20 carbon atoms, or a substituted or unsubstituted alkyl group with 1 to 7 carbon atoms.

[0066] In this invention, the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, or n-decyl.

[0067] In this invention, the substituted or unsubstituted alkenyl group having at least a double bond at the end, having 1 to 10 carbon atoms, is preferably vinyl, 1-methylvinyl, allyl, 3-butenyl, 1-methylallyl, 2-methylallyl, 4-pentenyl, or 5-hexenyl.

[0068] In this invention, the substituted or unsubstituted alicyclic organic groups with 3 to 20 carbon atoms are preferably cyclopentyl, cyclohexyl, adamantyl, norbornyl, borneolyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylmethyl, cyclohexylethyl, adamantylmethyl, adamantylethyl, norbornylmethyl, norbornylethyl, borneolylmethyl, borneolylethyl, 3-hydroxy-1-adamantyl, 4-hydroxy-1-adamantyl, or 4-oxy-1-adamantyl.

[0069] In this invention, the aryl group having 6 to 20 carbon atoms is preferably phenyl, o-tolyl, m-tolyl, p-tolyl, p-hydroxyphenyl, 1-naphthyl, 1-anthrayl, or benzyl.

[0070] In this invention, the straight-chain or branched alkoxy group having 1 to 10 carbon atoms is preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, or tert-butoxy.

[0071] In this invention, the aryloxy group having 6 to 20 carbon atoms is preferably phenoxy, p-hydroxyphenoxy, o-tolyloxy, m-tolyloxy, or p-tolyloxy.

[0072] In this invention, the straight-chain or branched alkyl carbonyl group having 2 to 10 carbon atoms is preferably methyl carbonyl, ethyl carbonyl, n-propyl carbonyl, isopropyl carbonyl, n-butyl carbonyl, or tert-butyl carbonyl.

[0073] In this invention, the aryl carbonyl group with 7 to 20 carbon atoms can include phenyl carbonyl and benzyl carbonyl.

[0074] In this invention, the straight-chain or branched alkyl carbonyloxy group having 2 to 10 carbon atoms is preferably methyl carbonyloxy, ethyl carbonyloxy, n-propyl carbonyloxy, isopropyl carbonyloxy, n-butyl carbonyloxy, or tert-butyl carbonyloxy.

[0075] In this invention, the aryl carbonyloxy group with 7 to 20 carbon atoms is preferably phenyl carbonyloxy or benzyl carbonyloxy.

[0076] In this invention, the straight-chain or branched alkoxycarbonyl group with 2 to 10 carbon atoms is preferably methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, isopropoxycarbonyl, n-butoxycarbonyl or tert-butoxycarbonyl.

[0077] In this invention, the aryloxycarbonyl group with 7 to 20 carbon atoms is preferably phenoxycarbonyl or benzyloxycarbonyl.

[0078] In this invention, Q +The ion is a monazine ion, preferably a trimethylsulfonium ion, a tributylsulfonium ion, a dimethyl(2-oxocyclohexyl)sulfonium ion, a bis(2-oxocyclohexyl)methylsulfonium ion, a (10-camphenyl)methyl(2-oxocyclohexyl)sulfonium ion, a (2-norbornel)methyl(2-oxocyclohexyl)sulfonium ion, a triphenylsulfonium ion, a diphenyltolylsulfonium ion, a diphenylxylmethylsulfonium ion, a daidzyl diphenylsulfonium ion, a (tert-butylphenyl)diphenylsulfonium ion, a (octylphenyl)diphenylsulfonium ion, a (cyclohexylphenyl)diphenylsulfonium ion, a biphenyl diphenylsulfonium ion, a (hydroxymethylphenyl)diphenylsulfonium ion, a (methoxymethylphenyl)diphenylsulfonium ion, a (acetylphenyl)diphenylsulfonium ion, a (benzoylphenyl)diphenylsulfonium ion, or a (hydroxymethylphenyl)diphenylsulfonium ion. (B-)-diphenylsulfonium carbonylphenyl (B-)-diphenylsulfonium ion, ... ) Phenylacetium ion, bis(octylphenyl)phenylsulfonium ion, bis(cyclohexylphenyl)phenylsulfonium ion, diphenylphenylsulfonium ion, bis(hydroxymethylphenyl)phenylsulfonium ion, bis(methoxymethylphenyl)phenylsulfonium ion, bis(acetylphenyl)phenylsulfonium ion, bis(benzoylphenyl)phenylsulfonium ion, bis(hydroxycarbonylphenyl)phenylsulfonium ion, bis(methoxycarbonylphenyl)phenylsulfonium ion, bis(trifluoromethylphenyl)phenylsulfonium ion, bis(fluorophenyl)phenylsulfonium ion, bis(chlorophenyl)phenylsulfonium ion, bis(bromophenyl)phenylsulfonium ion, bis(iodophenyl)phenylsulfonium ion, di(pentafluorophenyl)phenylsulfonium ion, bis(hydroxyphenyl)phenylsulfonium ion, bis(methoxyphenyl)phenylsulfonium ion, bis(butoxyphenyl)phenylsulfonium ion , bis(acetoxyphenyl)phenylsulfonium ion, bis(benzoyloxyphenyl)phenylsulfonium ion, bis(dimethylcarbamoylphenyl)phenylsulfonium ion, bis(acetylamidophenyl)phenylsulfonium ion, trimethylmethylsulfonium ion, tri(xylmethyl)sulfonium ion, trimethylphenylsulfonium ion, tri(tert-butylphenyl)sulfonium ion, tri(octylphenyl)sulfonium ion, tri(cyclohexylphenyl)sulfonium ion, triphenylsulfonium ion, tri(hydroxymethylphenyl)sulfonium ion, tri(methoxymethylphenyl)sulfonium ion, tri(acetylphenyl)sulfonium ion, tri(benzoylphenyl)sulfonium ion, tri(hydroxycarbonylphenyl)sulfonium ion, tri(methoxycarbonylphenyl)sulfonium ion, tri(trifluoromethylphenyl)sulfonium ion, tri(fluorophenyl)sulfonium ion, tri(chlorophenyl)sulfonium ion,Tris(bromophenyl)sulfonium ion, tris(iodophenyl)sulfonium ion, di(pentafluorophenyl)sulfonium ion, tris(hydroxyphenyl)sulfonium ion, tris(methoxyphenyl)sulfonium ion, tris(butoxyphenyl)sulfonium ion, tris(acetoxyphenyl)sulfonium ion, tris(benzoyloxyphenyl)sulfonium ion, tris(dimethylcarbamoylphenyl)sulfonium ion, tris(acetylamidophenyl)sulfonium ion, methyldiphenylsulfonium ion, ethyldiphenylsulfonium ion, butyldiphenylsulfonium ion, hexyldiphenylsulfonium ion, octyldiphenylsulfonium ion, cyclohexyldiphenylsulfonium ion, 2 -O-cyclohexyldiphenylsulfonium ion, norbornyldiphenylsulfonium ion, camphenyldiphenylsulfonium ion, pinyldiphenylsulfonium ion, naphthyldiphenylsulfonium ion, anthraceneyldiphenylsulfonium ion, benzyldiphenylsulfonium ion, trifluoromethyldiphenylsulfonium ion, methoxycarbonylmethyldiphenylsulfonium ion, butoxycarbonylmethyldiphenylsulfonium ion, benzoylmethyldiphenylsulfonium ion, (methylthiophenyl)diphenylsulfonium ion, (phenylthiophenyl)diphenylsulfonium ion, (acetylphenylthiophenyl)diphenylsulfonium ion, dimethylphenylsulfonium ion, diethylphenyl Sulfonium ion, dibutylphenylsulfonium ion, dihexylphenylsulfonium ion, dioctylphenylsulfonium ion, dicyclohexylphenylsulfonium ion, bis(2-oxocyclohexyl)phenylsulfonium ion, dinorbornelphenylsulfonium ion, dicamphenolylphenylsulfonium ion, dipinelphenylsulfonium ion, dinaphthylphenylsulfonium ion, dibenzylphenylsulfonium ion, trifluoromethyldiphenylsulfonium ion, bis(methoxycarbonylmethyl)phenylsulfonium ion, bis(butoxycarbonylmethyl)phenylsulfonium ion, dibenzoylmethylphenylsulfonium ion, bis(methylthiophenyl)phenylsulfonium ion, bis(phenylthio)phenylsulfonium ion Phenyl)phenylsulfonium ion, bis(acetylphenylthiophenyl)phenylsulfonium ion, dimethyl(2-oxocyclohexyl)sulfonium ion, bis(2-oxocyclohexyl)methylsulfonium ion, (10-camphenyl)methyl(2-oxocyclohexyl)sulfonium ion, (2-norbornyl)methyl(2-oxocyclohexyl)sulfonium ion, trimethylsulfonium ion, triethylsulfonium ion, tributylsulfonium ion, dihexylmethylsulfonium ion, trioctylsulfonium ion, dicyclohexylethylsulfonium ion, methyltetrahydrothiophenonium ion, methyltetrahydrothiophenonium ion, or triphenoxysulfonium ion;

[0079] The preparation method includes the following steps:

[0080] 2-Bromo-2,2-difluoroacetate, sodium borohydride, and an organic solvent were mixed and subjected to a reduction reaction to obtain 2-bromo-2,2-difluoroethanol.

[0081] The 2-bromo-2,2-difluoroethanol, triphenylmethylthiol, base and organic solvent were mixed and subjected to a substitution reaction to obtain a compound having the structure shown in formula a.

[0082]

[0083] A compound having the structure shown in formula a undergoes an acylation reaction with an acyl chloride compound having the structure shown in formula b to obtain a compound having the structure shown in formula c.

[0084]

[0085] A compound having the structure shown in formula c undergoes a deprotection reaction with trifluoroacetic acid to give a compound having the structure shown in formula d.

[0086]

[0087] A compound having the structure shown in formula d, hydrogen peroxide, and an organic solvent are mixed and subjected to an oxidation reaction to obtain a compound having the structure shown in formula e.

[0088]

[0089] A compound having the structure shown in Formula e undergoes an ion exchange reaction with a monovalent onium salt to obtain a photoacid-producing sulfonate having the structure shown in Formula I.

[0090] This invention involves mixing 2-bromo-2,2-difluoroacetate, sodium borohydride, and an organic solvent, and then performing a reduction reaction to obtain 2-bromo-2,2-difluoroethanol. In this invention, the 2-bromo-2,2-difluoroacetate is preferably methyl 2-bromo-2,2-difluoroacetate or ethyl 2-bromo-2,2-difluoroacetate. In this invention, the mass ratio of 2-bromo-2,2-difluoroacetate to sodium borohydride is preferably 10:3 to 5, more preferably 10:3 to 4.

[0091] In this invention, the organic solvent is preferably one or more selected from tetrahydrofuran, dioxane, diethyl ether, methyl tert-butyl ether, and isopropyl ether. In this invention, the mass ratio of the 2-bromo-2,2-difluoroacetate to the volume ratio of the organic solvent is preferably 100 g: 1000 mL.

[0092] In this invention, the preferred mixing method is to first stir and mix 2-bromo-2,2-difluoroacetate with an organic solvent in an ice bath, and then slowly add tetrahydrofuran; the preferred stirring time for 2-bromo-2,2-difluoroacetate and the organic solvent is 10 min.

[0093] In this invention, the temperature of the reduction reaction is preferably 0-70°C, more preferably 10-60°C, and even more preferably 20-50°C; the reaction is detected by gas chromatography.

[0094] After the reduction reaction is completed, the present invention preferably adds water to quench the resulting reduction reaction product, uses a desiccant to remove water, and the resulting reaction solution is directly used for the next reaction. In the present invention, the desiccant is preferably anhydrous sodium sulfate.

[0095] In this invention, 2-bromo-2,2-difluoroethanol, triphenylmethylthiol, a base, and an organic solvent are mixed and subjected to a substitution reaction to obtain a compound having the structure shown in formula a. In this invention, the preferred mass ratio of the initial raw material 2-bromo-2,2-difluoroacetate to triphenylmethylthiol is 1:2 to 1:3.

[0096] In this invention, the alkali is preferably one or more selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, ammonia, a methanol solution of ammonia, ammonium bicarbonate, sodium thiosulfate, sodium bicarbonate, triethylamine, diisopropylethylamine, pyridine, n-butyllithium, isobutyllithium, tert-butyllithium, diisopropylaminolithium, bis(trimethylsilyl)aminolithium, sodium bis(trimethylsilyl)amino, potassium bis(trimethylsilyl)amino, imidazole, sodium methoxide, sodium ethoxide, sodium amino, potassium trimethylsilanolate, and tetramethylethylenediamine. In this invention, the molar ratio of the alkali to triphenylmethylthiol is preferably 2:1 to 2.5:1.

[0097] In this invention, the organic solvent is preferably dimethyl sulfoxide and / or N,N-dimethylformamide.

[0098] In this invention, the substitution reaction is preferably carried out in an inert gas environment. The temperature of the substitution reaction is preferably 0–80°C, more preferably 10–70°C, and even more preferably 20–60°C; the time is preferably 2–3 hours. Gas chromatography shows that the reaction ends after 2-bromo-2,2-difluoroethanol is completely consumed.

[0099] Following the substitution reaction, the present invention dilutes the resulting substitution reaction product with water, extracts it with dichloromethane, combines the organic phases, and passes them through a silica gel column to obtain a pure compound having the structure shown in formula a.

[0100] In this invention, the triphenylmethylthiol can be replaced with tert-butylthiol.

[0101] In this invention, a compound having the structure shown in formula a undergoes an acylation reaction with an acyl chloride compound having the structure shown in formula b to obtain a compound having the structure shown in formula c. In this invention, the molar ratio of the compound having the structure shown in formula a to the acyl chloride compound having the structure shown in formula b is preferably 1:1.

[0102] In this invention, the acylation reaction is preferably carried out in the presence of triethylamine, and the molar ratio of triethylamine to the compound having the structure shown in formula a is preferably 1:2.

[0103] In this invention, the organic solvent used in the acylation reaction is preferably one or more of dichloromethane, dichloroethane, and chloroform.

[0104] In this invention, the acylation reaction is preferably carried out at room temperature, specifically at 25–30°C, and the reaction time is preferably 2–3 hours.

[0105] Following the acylation reaction, the present invention preferably performs post-treatment on the resulting acylation reaction solution, the post-treatment including:

[0106] The resulting acylation reaction solution was extracted, dried, concentrated, and then passed through a silica gel column.

[0107] In this invention, a compound having the structure shown in formula c undergoes a deprotection reaction with trifluoroacetic acid to obtain a compound having the structure shown in formula d. In this invention, the preferred mass-to-volume ratio of the compound having the structure shown in formula c to trifluoroacetic acid is 69 g:151 mL to 69 g:160 mL.

[0108] In this invention, the organic solvent used in the deprotection reaction is preferably one or more of dichloromethane, dichloroethane, and chloroform.

[0109] In this invention, the temperature of the deprotection reaction is preferably room temperature, specifically preferably 25-30°C; the time is preferably 12-16 hours, more preferably 13-15 hours.

[0110] After the deprotection reaction, the present invention performs rotary evaporation on the obtained deprotection reaction solution, and the resulting product is directly added to the next reaction step.

[0111] This invention involves mixing a compound having the structure shown in formula d, hydrogen peroxide, and an organic solvent, and then performing an oxidation reaction to obtain a compound having the structure shown in formula e. In this invention, the hydrogen peroxide is preferably an aqueous solution of hydrogen peroxide, and the mass concentration of the aqueous solution of hydrogen peroxide is preferably 30%. In this invention, the mass ratio of the compound having the structure shown in formula d to the volume ratio of the aqueous solution of hydrogen peroxide is preferably 70 g: 150 mL.

[0112] In this invention, the organic solvent is preferably one or more of tetrahydrofuran, dioxane, diethyl ether, methyl tert-butyl ether, and isopropyl ether.

[0113] In this invention, the temperature of the oxidation reaction is preferably ≤20℃, and the time is preferably 12-16h, more preferably 13-15h.

[0114] After the oxidation reaction, the present invention uses sodium sulfite for quenching, repeatedly extracts with n-hexane, and then evaporates the aqueous phase to dryness.

[0115] In this invention, a compound having the structure shown in Formula e undergoes an ion exchange reaction with a monovalent onium salt to obtain a photoacid-producing sulfonate having the structure shown in Formula I. In this invention, the preferred structural formula of the monovalent onium salt is Q. + X - X- It is a halide ion, an alkyl sulfonate ion, or an aryl sulfonate ion; as a specific embodiment of the present invention, the monovalent onium salt is preferably diphenyl (p-tolyl) sulfonium bromide.

[0116] In this invention, the molar ratio of the compound having the structure shown in Formula e to the monovalent onium salt is preferably 1:1.

[0117] In this invention, the ion exchange reaction is preferably carried out in the presence of sodium bicarbonate, and the molar ratio of sodium bicarbonate to monovalent onium salt is preferably 2:1.

[0118] In this invention, the solvent used in the ion exchange reaction is preferably dichloromethane and water, and the volume ratio of dichloromethane to water is preferably 2:1.

[0119] In this invention, the temperature of the ion exchange reaction is preferably room temperature, and the time is preferably 16 hours.

[0120] After the ion exchange reaction, the present invention preferably separates the resulting reaction solution into layers and takes the organic phase; the resulting aqueous phase is then extracted with dichloromethane, the organic phases are combined, concentrated, and recrystallized with ethyl acetate to obtain a photo-induced acid-producing agent sulfonate solid with the structure shown in Formula I.

[0121] The synthetic route of the photoacid-producing sulfonate of this invention is as follows: Figure 1 As shown.

[0122] The following detailed description, in conjunction with embodiments, illustrates a method for preparing a photoacid-generating sulfonate salt for ARF photoresist provided by the present invention. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0123] Example 1

[0124] (1) Preparation of 2-bromo-2,2-difluoroethanol

[0125]

[0126] 100 g (0.493 mol) of ethyl 2-bromo-2,2-difluoroacetate and 1000 mL of THF were added to a flask, and the mixture was stirred in an ice bath for 10 minutes. Sodium borohydride (30 g, 0.793 mol) was slowly added, and the reaction mixture was refluxed at 70 °C. Gas chromatography was used to confirm the end of the reaction. The mixture was quenched with 10 mL of water. The product has a very low boiling point and cannot be concentrated under low pressure. After removing water with anhydrous sodium sulfate, the reaction solution was directly added to the next step of the reaction.

[0127] (2) Preparation of 2-triphenylmethylthio-2,2-difluoroethanol

[0128]

[0129] The crude product of 2-bromo-2,2-difluoroethanol and lithium hydroxide (47.3 g, 1.972 mol) were added to a flask, and the mixture was purged with nitrogen. Triphenylmethanethiol (272.5 g, 0.986 mol) was slowly added dropwise to the reaction mixture. The reaction was stirred at 80 °C for 3 hours. Gas chromatography showed that the reaction was complete after the 2-bromo-2,2-difluoroethanol was consumed.

[0130] The reaction solution was diluted with water (2000 mL) and extracted with dichloromethane (500 mL × 3). The organic phases were combined and subjected to routine post-treatment before being passed through a silica gel column to obtain 140.6 g of a pale yellow oil.

[0131] (3) Preparation of ethyl 1-adamantanecarboxylic acid (2'-triphenylmethylthio-2',2'-difluoro)

[0132]

[0133] 2-Triphenylmethylthio-2,2-difluoroethanol (50 g, 0.14 mol), dichloromethane (500 mL), and triethylamine (28.33 g, 0.28 mol) were added to a flask and stirred for 10 minutes. 1-Adamantaneformyl chloride (27.8 g, 0.14 mol) was added dropwise to the reaction mixture. The reaction was stirred at room temperature for 3 hours.

[0134] After routine post-treatment, the reaction solution was passed through a silica gel column to obtain 69g of pale yellow oil.

[0135] (4) Preparation of ethyl 1-adamantanecarboxylic acid (2'-thio-2',2'-difluoro)

[0136]

[0137] 69 g (0.133 mol) of ethyl 1-adamantanecarboxylic acid (2'-triphenylmethylthio-2',2'-difluoro) and 500 mL of dichloromethane were added to a flask and stirred for 10 minutes. Trifluoroacetic acid (151 mL) was then added dropwise. The reaction mixture was stirred at room temperature for 16 hours. The reaction solution was evaporated to dryness to obtain 70 g of crude product, which was directly added to the next reaction step.

[0138] (5) Preparation of 1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonic acid

[0139]

[0140] Add reagents 1-adamantanecarboxylic acid (2'-thio-2',2'-difluoro) ethyl ester (crude product 70 g) and tetrahydrofuran (300 mL) to a flask and stir for 10 minutes. Add hydrogen peroxide (30%, 150 mL) dropwise to the reaction system, monitoring the reaction temperature below 20°C. Stir the reaction at room temperature for 16 hours.

[0141] After the reaction was completed, the solution was quenched with sodium sulfite, repeatedly extracted with n-hexane, and the aqueous phase was dried by rotary evaporation to obtain 43g of white solid.

[0142] (6) Preparation of (4'-methylphenyl)diphenylthio-1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonate

[0143]

[0144] The reagents 1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonic acid (43 g, 0.133 mol), diphenyl(p-tolyl)bromosulfonate (47.52 g, 0.133 mol), sodium bicarbonate (22.3 g, 0.266 mol), dichloromethane (2 L), and water (1 L) were added to a flask and stirred for 16 hours. After the reaction solution separated into layers, the organic phase was collected, and the aqueous phase was extracted again with dichloromethane (500 mL × 3). The organic phases were combined, concentrated, and recrystallized from ethyl acetate to give 60 g of white solid with a purity of 99%.

[0145] The 1-F NMR spectrum of the obtained (4'-methylphenyl)diphenylthio-1-adamantanoyl-(1',1'-difluorooxyethyl)sulfonate is shown below. Figure 2 As shown, the 1-H NMR spectrum is as follows: Figure 3 As shown, the high-performance liquid chromatogram is as follows: Figure 4 As shown.

[0146] Example 2

[0147] (1) Preparation of 2-bromo-2,2-difluoroethanol

[0148]

[0149] 100 g (0.529 mol) of methyl 2-bromo-2,2-difluoroacetate and 1000 mL of THF were added to a flask, and the mixture was stirred in an ice bath for 10 minutes. Sodium borohydride (30 g, 0.793 mol) was slowly added, and the reaction mixture was refluxed at 70 °C. Gas chromatography was used to confirm the end of the reaction. The mixture was quenched with 10 mL of water. The product has a very low boiling point and cannot be concentrated under low pressure. After dehydration with anhydrous sodium sulfate, the reaction solution was directly added to the next step of the reaction.

[0150] (2) Preparation of 2-triphenylmethylthio-2,2-difluoroethanol

[0151]

[0152] The crude product of 2-bromo-2,2-difluoroethanol and lithium hydroxide (47.3 g, 1.972 mol) were added to a flask, and the mixture was purged with nitrogen. Triphenylmethanethiol (272.5 g, 0.986 mol) was slowly added dropwise to the reaction mixture. The reaction was stirred at 80 °C for 3 hours. Gas chromatography showed that the reaction was complete after the 2-bromo-2,2-difluoroethanol was consumed.

[0153] The reaction solution was diluted with water (2000 mL) and extracted with dichloromethane (500 mL × 3). The organic phases were combined and subjected to routine post-treatment before being passed through a silica gel column to obtain 140.6 g of a pale yellow oil.

[0154] (3) Preparation of 4'-dimethylaminobenzoic acid-2,2-difluoro-2-triphenylmethylthioethyl ester

[0155]

[0156] 2-Triphenylmethylthio-2,2-difluoroethanol (50 g, 0.14 mol), dichloromethane (500 mL), and triethylamine (28.33 g, 0.28 mol) were added to a flask and stirred for 10 minutes. 4-Dimethylaminobenzoyl chloride (25.7 g, 0.14 mol) was then added dropwise to the reaction mixture. The reaction was stirred at room temperature for 3 hours.

[0157] After routine post-treatment, the reaction solution was passed through a silica gel column to obtain 69g of pale yellow oil.

[0158] (4) Preparation of 4'-dimethylaminobenzoic acid-2,2-difluoro-2-mercaptoethyl ester

[0159]

[0160] 100 g (0.198 mol) of 4'-dimethylaminobenzoic acid-2,2-difluoro-2-triphenylmethylthioethyl ester and 1000 mL of dichloromethane were added to a flask and stirred for 10 minutes. Trifluoroacetic acid (200 mL) was then added dropwise. The reaction mixture was stirred at room temperature for 16 hours. After evaporating the solution to dryness, 52 g of the crude product was directly added to the next reaction step.

[0161] (5) Preparation of ethyl 4'-dimethylaminobenzoic acid-2,2-difluoro-2-sulfonate

[0162]

[0163] Add reagents 4'-dimethylaminobenzoic acid-2,2-difluoro-2-mercaptoethyl ester (crude product 52 g) and tetrahydrofuran (300 mL) to a flask and stir for 10 minutes. Add hydrogen peroxide (30%, 150 mL) dropwise to the reaction system, monitoring the reaction temperature below 20°C. Stir the reaction at room temperature for 16 hours.

[0164] After the reaction was completed, the solution was quenched with sodium sulfite, repeatedly extracted with n-hexane, and the aqueous phase was dried by rotary evaporation to obtain 100g of white solid.

[0165] (6) Preparation of triphenylthio-4'-dimethylaminobenzoic acid-2,2-difluoro-2-sulfonate ethyl ester sulfonate

[0166]

[0167] 4'-Dimethylaminobenzoic acid-2,2-difluoro-2-sulfonyl ethyl ester (100 g, crude product), triphenyl chlorosulfonate (96.62 g, 0.323 mol), sodium bicarbonate (44.6 g, 0.323 mol), dichloromethane (2 L), and water (1 L) were added to a flask and stirred for 16 hours. After the reaction solution separated into layers, the organic phase was collected, and the aqueous phase was extracted again with dichloromethane (500 mL × 3). The organic phases were combined, concentrated, and recrystallized from ethyl acetate to give 54 g of white solid with a purity of 99%.

[0168] The 1-F NMR spectrum of the obtained triphenylthio-4'-dimethylaminobenzoic acid-2,2-difluoro-2-sulfonyl ethyl ester sulfonate is shown below. Figure 5 As shown, the 1-H NMR spectrum is as follows: Figure 6 As shown, the high-performance liquid chromatogram is as follows: Figure 7 As shown.

[0169] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a photoacid-generating sulfonate for ARF photoresist, wherein the photoacid-generating sulfonate has the structure shown in Formula I: Equation I; In formula I, R 1 It is a 1-adamantyl group, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 7 carbon atoms; The substituent of the aryl group is fluorine or hydroxyl; Q + The onnnage ion is a trimethylsulfonium ion, tributylsulfonium ion, dimethyl(2-oxocyclohexyl)sulfonium ion, bis(2-oxocyclohexyl)methylsulfonium ion, (10-camphenyl)methyl(2-oxocyclohexyl)sulfonium ion, (2-norbornyl)methyl(2-oxocyclohexyl)sulfonium ion, triphenylsulfonium ion, diphenyltolylsulfonium ion, diphenylxylmethylsulfonium ion, daidzyl diphenylsulfonium ion, (tert-butylphenyl) diphenylsulfonium ion, (octylphenyl) diphenylsulfonium ion, (cyclohexylphenyl) diphenylsulfonium ion, biphenyl diphenylsulfonium ion, (hydroxymethylphenyl) diphenylsulfonium ion, (methoxymethylphenyl) diphenylsulfonium ion, (acetylphenyl) diphenylsulfonium ion, (benzoylphenyl) diphenylsulfonium ion. Ions, (hydroxycarbonylphenyl)diphenylsulfonium ion, (methoxycarbonylphenyl)diphenylsulfonium ion, (trifluoromethylphenyl)diphenylsulfonium ion, (fluorophenyl)diphenylsulfonium ion, (chlorophenyl)diphenylsulfonium ion, (bromophenyl)diphenylsulfonium ion, (iodophenyl)diphenylsulfonium ion, pentafluorophenyldiphenylsulfonium ion, (hydroxyphenyl)diphenylsulfonium ion, (methoxyphenyl)diphenylsulfonium ion, (butoxyphenyl)diphenylsulfonium ion, (acetoxyphenyl)diphenylsulfonium ion, (benzoyloxyphenyl)diphenylsulfonium ion, (dimethylcarbamoylphenyl)diphenylsulfonium ion, (acetylamidophenyl)diphenylsulfonium ion, phenylxylylsulfonium ion, phenyl di(xylylyl)sulfonium ion, dilylphenylsulfonium ion, bis (tert-butylphenyl)phenylsulfonium ion, bis(octylphenyl)phenylsulfonium ion, bis(cyclohexylphenyl)phenylsulfonium ion, diphenylphenylsulfonium ion, bis(hydroxymethylphenyl)phenylsulfonium ion, bis(methoxymethylphenyl)phenylsulfonium ion, bis(acetylphenyl)phenylsulfonium ion, bis(benzoylphenyl)phenylsulfonium ion, bis(hydroxycarbonylphenyl)phenylsulfonium ion, bis(methoxycarbonylphenyl)phenylsulfonium ion, bis(trifluoromethylphenyl)phenylsulfonium ion, bis(fluorophenyl)phenylsulfonium ion, bis(chlorophenyl)phenylsulfonium ion, bis(bromophenyl)phenylsulfonium ion, bis(iodophenyl)phenylsulfonium ion, di(pentafluorophenyl)phenylsulfonium ion, bis(hydroxyphenyl)phenylsulfonium ion, bis(methoxyphenyl)phenylsulfonium ion, bis(butoxy)phenylsulfonium ion phenyl)phenylsulfonium ion, bis(acetoxyphenyl)phenylsulfonium ion, bis(benzoyloxyphenyl)phenylsulfonium ion, bis(dimethylcarbamoylphenyl)phenylsulfonium ion, bis(acetylamidophenyl)phenylsulfonium ion, trimethylmethylsulfonium ion, tri(xylmethyl)sulfonium ion, trimethylphenylsulfonium ion, tri(tert-butylphenyl)sulfonium ion, tri(octylphenyl)sulfonium ion, tri(cyclohexylphenyl)sulfonium ion, triphenylsulfonium ion, tri(hydroxymethylphenyl)sulfonium ion, tri(methoxymethylphenyl)sulfonium ion, tri(acetylphenyl)sulfonium ion, tri(benzoylphenyl)sulfonium ion, tri(hydroxycarbonylphenyl)sulfonium ion, tri(methoxycarbonylphenyl)sulfonium ion, tri(trifluoromethylphenyl)sulfonium ion, tri(fluorophenyl)sulfonium ion,Tris(chlorophenyl)sulfonium ion, tris(bromophenyl)sulfonium ion, tris(iodophenyl)sulfonium ion, di(pentafluorophenyl)sulfonium ion, tris(hydroxyphenyl)sulfonium ion, tris(methoxyphenyl)sulfonium ion, tris(butoxyphenyl)sulfonium ion, tris(acetoxyphenyl)sulfonium ion, tris(benzoyloxyphenyl)sulfonium ion, tris(dimethylcarbamoylphenyl)sulfonium ion, tris(acetylamidophenyl)sulfonium ion, methyldiphenylsulfonium ion, ethyldiphenylsulfonium ion, butyldiphenylsulfonium ion, hexyldiphenylsulfonium ion, octyldiphenylsulfonium ion, cyclohexyl Diphenylsulfonium ion, 2-oxocyclohexyldiphenylsulfonium ion, norbornyldiphenylsulfonium ion, camphenyldiphenylsulfonium ion, pinyldiphenylsulfonium ion, naphthyldiphenylsulfonium ion, anthraceneyldiphenylsulfonium ion, benzyldiphenylsulfonium ion, trifluoromethyldiphenylsulfonium ion, methoxycarbonylmethyldiphenylsulfonium ion, butoxycarbonylmethyldiphenylsulfonium ion, benzoylmethyldiphenylsulfonium ion, (methylthiophenyl)diphenylsulfonium ion, (phenylthiophenyl)diphenylsulfonium ion, (acetylphenylthiophenyl)diphenylsulfonium ion, dimethylphenylsulfonium ion Diethylphenylsulfonium ion, dibutylphenylsulfonium ion, dihexylphenylsulfonium ion, dioctylphenylsulfonium ion, dicyclohexylphenylsulfonium ion, bis(2-oxocyclohexyl)phenylsulfonium ion, dinorbornelphenylsulfonium ion, dicamphenolylphenylsulfonium ion, dipinelphenylsulfonium ion, dinaphthylphenylsulfonium ion, dibenzylphenylsulfonium ion, trifluoromethyldiphenylsulfonium ion, bis(methoxycarbonylmethyl)phenylsulfonium ion, bis(butoxycarbonylmethyl)phenylsulfonium ion, dibenzoylmethylphenylsulfonium ion, bis(methylthiophenyl)phenylsulfonium ion, bis( (phenylthiophenyl)phenylsulfonium ion, bis(acetylphenylthiophenyl)phenylsulfonium ion, dimethyl(2-oxocyclohexyl)sulfonium ion, bis(2-oxocyclohexyl)methylsulfonium ion, (10-camphenyl)methyl(2-oxocyclohexyl)sulfonium ion, (2-norbornyl)methyl(2-oxocyclohexyl)sulfonium ion, trimethylsulfonium ion, triethylsulfonium ion, tributylsulfonium ion, dihexylmethylsulfonium ion, trioctylsulfonium ion, dicyclohexylethylsulfonium ion, methyltetrahydrothiophenonium ion, methyltetrahydrothiophenonium ion, or triphenoxysulfonium ion; The preparation method includes the following steps: 2-Bromo-2,2-difluoroacetate, sodium borohydride, and an organic solvent were mixed and subjected to a reduction reaction to obtain 2-bromo-2,2-difluoroethanol. The 2-bromo-2,2-difluoroethanol, triphenylmethylthiol, base and organic solvent were mixed and subjected to a substitution reaction to obtain a compound having the structure shown in formula a. Formula a; A compound having the structure shown in formula a undergoes an acylation reaction with an acyl chloride compound having the structure shown in formula b to obtain a compound having the structure shown in formula c. Formula b; Formula c; A compound having the structure shown in formula c undergoes a deprotection reaction with trifluoroacetic acid to give a compound having the structure shown in formula d. Formula d; A compound having the structure shown in formula d, hydrogen peroxide, and an organic solvent are mixed and subjected to an oxidation reaction to obtain a compound having the structure shown in formula e. Formula e; A compound having the structure shown in Formula e undergoes an ion exchange reaction with a monovalent onium salt to obtain a photoacid-producing sulfonate having the structure shown in Formula I; the monovalent onium salt has the structural formula Q. + X - X - It can be a halide ion, an alkyl sulfonate ion, or an aryl sulfonate ion.

2. The preparation method according to claim 1, characterized in that, The 2-bromo-2,2-difluoroacetate is methyl 2-bromo-2,2-difluoroacetate or ethyl 2-bromo-2,2-difluoroacetate. The reduction reaction is carried out at a temperature of 0~70℃.

3. The preparation method according to claim 1 or 2, characterized in that, The alkali is one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, ammonia, ammonia in methanol, ammonium bicarbonate, sodium thiosulfate, sodium bicarbonate, triethylamine, diisopropylethylamine, pyridine, n-butyllithium, isobutyllithium, tert-butyllithium, diisopropylaminolithium, bis(trimethylsilyl)aminolithium, sodium bis(trimethylsilyl)amino, potassium bis(trimethylsilyl)amino, imidazole, sodium methoxide, sodium ethoxide, sodium amino, potassium trimethylsilanolate, and tetramethylethylenediamine; The substitution reaction is carried out at a temperature of 0-80℃ for 2-3 hours.

4. The preparation method according to claim 1, characterized in that, The acyl chloride compound having the structure shown in Formula b is 1-adamantaneformyl chloride, arylformyl chloride, substituted arylformyl chloride, or C1-C7 alkyl acyl chloride.

5. The preparation method according to claim 1, characterized in that, The acylation reaction is carried out at a temperature of 25-30°C for 2-3 hours. The deprotection reaction is carried out at a temperature of 25-30°C for 12-16 hours.

6. The preparation method according to claim 1, characterized in that, The oxidation reaction is carried out at a temperature of ≤20℃ for 12~16h.

7. The preparation method according to claim 1, characterized in that, The ion exchange reaction is carried out at a temperature of 25-30°C for 12-16 hours.

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