KrF light source thick film photoresist composition and preparation method thereof

Abstract

The present invention discloses a KrF light source thick-film photoresist composition and its preparation method. Specifically, the present invention discloses a KrF thick-film photoresist composition containing a photoacid generator as shown in Formula I. The photoresist film formed from this photoresist composition has good rectangular properties. #imgabs0#

Description

Technical Field

[0001] The invention relates to a KrF light source thick film photoresist composition and a preparation method thereof. Background Art

[0002] Currently in the field of semiconductor manufacturing, KrF light source thick film photoresist is used in the manufacturing process of LCD (liquid crystal display) / BUMP bumps / MEMS microelectromechanical systems / 3D-NAND memory chips. This type of photoresist is different from conventional KrF thin layer photoresist and ArF light source photoresist, but has its own unique properties.

[0003] Although integrated circuit semiconductor chip manufacturing technology is developing rapidly, the technology of thick-film photoresist for the corresponding KrF light source is not yet fully mature, which is a hot area of ​​KrF photoresist research. Summary of the Invention

[0004] The present invention provides a KrF thick film photoresist composition and its preparation method and application. The photoresist film formed by the photoresist composition of the present invention has good rectangularity.

[0005] The present invention solves the above technical problems through the following technical solutions.

[0006] The present invention provides a KrF thick film photoresist composition, which includes a photoacid generator as shown in Formula I;

[0007]

[0008] In formula I, n is 0, 1, 2 or 3;

[0009] R1 is -COOR 1-1 or C 1-4 Alkyl; R 1-1 C 1-4 alkyl;

[0010] R2 is C 1-4 alkyl.

[0011] In a preferred embodiment, n is 0, 1 or 2.

[0012] In a preferred embodiment, R1 is -COOR 1-1 , where R 1-1 It is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, preferably ethyl.

[0013] In a preferred embodiment, R1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, preferably methyl.

[0014] In a preferred embodiment, R2 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, preferably methyl.

[0015] The photoacid generator is preferably any one of the following compounds:

[0016]

[0017]

[0018] In the present invention, the KrF thick film photoresist composition comprises the following components: the photoacid generator, photosensitive polymer, triethanolamine and solvent;

[0019] The photosensitive polymer can be a polymer that can be used for deep ultraviolet (DUV) light and carries out photochemical reaction. For example, the photosensitive polymer can be a polymer that carries out chemical reaction when the photoacid generator (PAG) mixed with the photosensitive polymer is exposed to light such as deep ultraviolet light and produces acid, and the acid produced in this way causes the polymer to carry out chemical reaction so that the polymer improves its hydrophilicity or hydrophobicity. It should be understood that the photosensitive polymer does not need to be directly sensitive to light (for example, the exposure of the photosensitive polymer to light does not need to change the chemical composition of the photosensitive polymer, although the chemical composition of the photosensitive polymer can change due to the acid produced by the PAG mixed with the photosensitive polymer exposed). In some embodiments, the solubility of the photosensitive polymer in alkali can increase due to photochemical reaction. In some embodiments, the photosensitive polymer can have a structure in which a protecting group is bonded to a repeating unit, and the protecting group can be deprotected during exposure so that the photosensitive polymer is well dissolved in alkali. The photoresist can be a positive photoresist, in which the part removed by the photoresist development thereafter is exposed to light (for example DUV light). Deprotection of the protecting group can generate new acids for chemical amplification.

[0020] The photosensitive polymer may be phenolic resin, polyhydroxystyrene resin, acrylic resin or a combination thereof.

[0021] In a preferred embodiment of the present invention, the KrF thick film photoresist composition is composed of the aforementioned photoacid generator, the aforementioned photosensitive polymer, triethanolamine and a solvent.

[0022] The phenolic resin may be a resin having a repeating unit represented by formula (IV),

[0023]

[0024] In formula (IV), R 5a is an acid-dissociable protecting group, and R 5b and R 5c Each of R is a hydrogen atom or a C1-C6 alkyl group.5a C1-C6 straight chain, branched or cyclic alkyl, vinyloxyethyl, tetrahydropyranyl, tetrahydrofuranyl, trialkylsilyl, isonorbornyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 3-tetrahydrofuranyl, 3-oxocyclohexyl, γ-butyrolactone-3-yl, mevalonolactone, γ-butyrolactone-2-yl, 3-methyl-γ-butyrolactone-3-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, 2,3-propylene carbonate-1-yl, 1-methoxyethyl, 1-ethoxyethyl, 1-(2-methoxy)ethyl, The alkyl group of the present invention may be alkyl, methyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl. The alkyl group of the present invention may be alkyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl. The alkyl group of the present invention may be alkyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl. The alkyl group of the present invention may be alkyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl. The alkyl group of the present invention may be alkyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl. The alkyl group of the present invention may be alkyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl.

[0025] The polyhydroxystyrene resin may be a resin having a repeating unit represented by formula (V),

[0026]

[0027]

[0028] In formula (V), R 7a is a hydrogen atom or C 1-6 Alkyl, and R 7b is an acid-cleavable protecting group. The definition of the acid-cleavable protecting group is as described above.

[0029] The polyhydroxystyrene resin may include another polymerizable compound as a repeating unit. Examples of the polymerizable compound may include, but are not limited to: monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond, such as 2-methacryloyloxyethylsuccinic acid, 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; Aryl (meth)acrylates, such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters, such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds, such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds, such as vinyl acetate; conjugated dienes, such as butadiene and isoprene; nitrile group-containing polymerizable compounds, such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds, such as vinyl chloride and vinylidene chloride; and amide bond-containing polymerizable compounds, such as acrylamide and methacrylamide.

[0030] The acrylic resin may be a resin having a repeating unit represented by formula (VI);

[0031]

[0032] In formula (VI), R 8a is a hydrogen atom, a C1-C6 linear or branched alkyl group, a fluorine atom or a C1-C6 linear or branched fluorinated alkyl group, and R 8b is an acid-cleavable protecting group. The definition of the acid-cleavable protecting group is as described above.

[0033] In one embodiment of the KrF thick film photoresist composition, the photosensitive polymer may include a (meth)acrylate-based polymer. The (meth)acrylate-based polymer may be an aliphatic (meth)acrylate-based polymer and may include, for example, polymethyl methacrylate (PMMA), poly(t-butyl methacrylate), poly(methacrylic acid), poly(norbornyl methacrylate), a binary or ternary copolymer photosensitive polymer of repeating units of the above-mentioned (meth)acrylate-based polymers, or a combination thereof.

[0034] The acrylic resin may include another polymerizable compound as a repeating unit. Examples of the polymerizable compound may include, but are not limited to: acrylic acid esters having an ether bond, such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate; monocarboxylic acids, such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids, such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond, such as 2-methacryloyloxyethylsuccinic acid, 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid; alkyl (meth)acrylates, such as (meth)acrylic acid. (meth)acrylate, such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate and cyclohexyl (meth)acrylate; hydroxyalkyl (meth)acrylates, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; aryl (meth)acrylates, such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters, such as diethyl maleate and dibutyl fumarate; aromatic compounds containing vinyl groups, such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene and α-ethylhydroxystyrene; aliphatic compounds containing vinyl groups, such as vinyl acetate; conjugated dienes, such as butadiene and isoprene; polymerizable compounds containing nitrile groups, such as acrylonitrile and methacrylonitrile; polymerizable compounds containing chlorine, such as vinyl chloride and vinylidene chloride; and polymerizable compounds containing amide bonds, such as acrylamide and methacrylamide.

[0035] In one embodiment of the KrF thick film photoresist composition, the photosensitive polymer may have the following structure:

[0036] where x 1 :y 1 :z 1 =66.5:8.5:25.

[0037] The photosensitive polymer can be obtained by a conventional addition polymerization reaction of a polymer monomer in the art. In one embodiment of the photoresist composition, the photosensitive polymer can be obtained by an addition polymerization reaction of monomer A, monomer B and monomer C, wherein monomer A is The monomer B is The monomer C is The molar ratio of monomer A, monomer B and monomer C is 66.5:8.5:25,

[0038] In one embodiment, the solvent for the polyaddition reaction is an ester solvent, preferably ethyl acetate.

[0039] In one embodiment, the temperature of the addition polymerization reaction is 75-80°C, preferably 78°C.

[0040] In one embodiment, the polyaddition reaction time is 6 to 10 hours, preferably 8 hours.

[0041] In one embodiment, after the addition polymerization reaction is completed, the following post-processing steps can be performed: 1) mixing the reaction solution with an alcohol solvent to produce a precipitate, mixing the precipitate with an ester solvent and dissolving it; 2) repeating the operation in 1) three times, then mixing it with an alcohol solvent to obtain a precipitate, and drying it.

[0042] In the post-treatment step, the alcohol solvent is preferably methanol.

[0043] In the post-treatment step, the ester solvent is preferably ethyl acetate.

[0044] In one embodiment of the KrF thick film photoresist composition, the weight average molecular weight (Mw) of the photosensitive polymer may be 10,000 to 600,000, for example, 20,000 to 400,000, or 22,000. The Mw value may be a value measured by gel permeation chromatography (GPC) using polystyrene as a standard.

[0045] In one embodiment of the KrF thick film photoresist composition, the polydispersity index (PDI) of the photosensitive polymer may be 1 to 3, for example, 2.1.

[0046] In one embodiment, the photosensitive polymer is prepared as follows:

[0047] (1) Add about 80g of monomer A, about 9g of monomer B and about 32g of monomer C into a reactor filled with nitrogen, then add 110g of ethyl acetate into the reactor, stir evenly and heat the reactor to 78°C, then add a mixture of ethyl acetate (25g) and benzoyl peroxide (2.2g) into the reactor, and complete the addition within 10 minutes. React at 78°C for 8 hours, stop the reaction, and cool the reaction liquid to room temperature; (2) Then add methanol (1000g) into the reactor to produce a precipitate. After 1 hour, drain the liquid in the reactor and add ethyl acetate (150g) into the reactor until the precipitate dissolves; (3) Repeat step (2) 3 times, then add methanol (1000g) into the reactor to obtain a solid precipitate, and place the solid precipitate in a vacuum drying oven to dry to obtain a photosensitive polymer. The molar ratio of monomer A, monomer B and monomer C is about 66.5:8.5:25. The structural formula of the photosensitive polymer finally prepared is where x 1 :y 1 :z 1 =66.5:8.5:25; its weight average molecular weight (Mw) is 22,000; and its polydispersity index (PDI) is 2.1.

[0048] The KrF thick film photoresist composition, the solvent is a conventional solvent for this type of reaction in the art, preferably an ester solvent, such as propylene glycol monomethyl ether acetate.

[0049] In the KrF thick film photoresist composition, the weight portion of the terpolymer is 100 parts.

[0050] In the KrF thick film photoresist composition, the weight portion of the photoacid generator is 5 parts, based on 100 parts by weight of the terpolymer.

[0051] In the KrF thick film photoresist composition, the weight portion of the triethanolamine is 0.1 parts, based on 100 parts by weight of the terpolymer.

[0052] In the KrF thick film photoresist composition, the weight portion of the solvent is 800 parts, based on 100 parts by weight of the terpolymer.

[0053] In a preferred embodiment of the present invention, the KrF thick film photoresist composition is prepared by dissolving 5 parts by weight of the aforementioned photoacid generator, 100 parts by weight of the aforementioned photosensitive polymer, and 0.1 parts by weight of triethanolamine in 800 parts by weight of propylene glycol monomethyl ether acetate; wherein the photosensitive polymer is obtained by subjecting the monomer A, the monomer B, and the monomer C to an addition polymerization reaction; the conditions and operation of the addition polymerization reaction are as described above, the molar ratio of the monomer A, the monomer B, and the monomer C is 66.5:8.5:25, and the weight average molecular weight (Mw) of the finally prepared photosensitive polymer is 22,000; and its polydispersity index (PDI) is 2.1.

[0054] The present invention also provides a use of the compound represented by formula I as described above as a photoacid generator in KrF thick film photoresist.

[0055] The present invention also provides a method for preparing a KrF thick film photoresist composition, which comprises the following steps: uniformly mixing a photoacid generator, a photosensitive polymer, triethanolamine and a solvent.

[0056] The mixing is a conventional operation in the art, wherein the mixing temperature is room temperature.

[0057] After the mixing is completed, a filtration operation may be further included. The filtration method is a conventional filtration method in the art, preferably filtration using a filter, wherein the pore size of the filter membrane is preferably 150 nm to 250 nm, more preferably 200 nm.

[0058] The present invention also provides a method for using the KrF thick film photoresist composition, the method comprising the following steps:

[0059] Step 1: coating the KrF thick film photoresist composition on a substrate surface to form a photoresist layer;

[0060] Step 2: pre-baking the photoresist layer;

[0061] Step 3: Copy the pattern on the mask to the pre-baked photoresist layer through exposure;

[0062] Step 4: Bake the exposed photoresist layer;

[0063] Step 5: Apply a developer to the baked photoresist layer for development to obtain a photoresist pattern.

[0064] In step 1, the substrate is preferably a silicon wafer;

[0065] In step 1, the coating method is preferably spin coating;

[0066] In step 1, the thickness of the composition layer is preferably 8.5 to 11.5 μm, more preferably 10 μm;

[0067] In step 2, the pre-baking temperature is preferably 95-125° C., more preferably 110° C.;

[0068] In step 3, the exposure wavelength is preferably 248 nm;

[0069] In step 4, the baking temperature is preferably 110-130° C., more preferably 120° C.;

[0070] In step 5, the developer is preferably a tetramethylammonium hydroxide aqueous solution, for example, a 2.38% by mass tetramethylammonium hydroxide aqueous solution;

[0071] In step 5, the development temperature is preferably 20-25° C., more preferably 23° C.;

[0072] In step 5, the development time is preferably 0.5 to 2 minutes, more preferably 1 minute.

[0073] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention.

[0074] The reagents and raw materials used in the present invention are commercially available.

[0075] The positive improvement effect of the present invention is that the film formed by using the photoresist composition of the present invention has the advantage of good rectangularity. DETAILED DESCRIPTION

[0076] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0077] 1. Photoacid generation function test of photoacid generator

[0078] A solution of the photoacid generator in acetonitrile was prepared to a concentration of 0.05 mol / L and placed in a quartz optical cell with a 1 cm optical path length. The sample was then irradiated with light (290 nm) from a xenon lamp, and the resulting acid was measured. The amount of acid generated was observed by the absorption of tetrabromophenol blue at 610 nm. The quantum yield was calculated by measuring the amount of light emitted using potassium trioxalatoferrate.

[0079] 2. Photoacid generator solubility test

[0080] 1.0 g of a photoacid generator was weighed and added to 100 g of propylene glycol monomethyl ether acetate. The mixture was magnetically stirred for 20 minutes, and the solubility was observed.

[0081] 3. Preparation of Photoresist Composition

[0082] 5 parts by weight of a photoacid generator, 100 parts by weight of a photosensitive polymer, and 0.1 parts by weight of triethanolamine were dissolved in 800 parts by weight of propylene glycol monomethyl ether acetate, and the mixture was mixed uniformly to prepare a photoresist composition.

[0083] The preparation method of the photosensitive polymer is as follows:

[0084] (1) Add about 80g of monomer A, about 9g of monomer B and about 32g of monomer C into a reactor filled with nitrogen, then add 110g of ethyl acetate into the reactor, stir evenly and heat the reactor to 78°C, then add a mixture of ethyl acetate (25g) and benzoyl peroxide (2.2g) into the reactor, and complete the addition within 10 minutes. React at 78°C for 8 hours, stop the reaction, and cool the reaction liquid to room temperature; (2) Then add methanol (1000g) into the reactor to produce a precipitate. After 1 hour, drain the liquid in the reactor and add ethyl acetate (150g) into the reactor until the precipitate dissolves; (3) Repeat step (2) 3 times, then add methanol (1000g) into the reactor to obtain a solid precipitate, and place the solid precipitate in a vacuum drying oven to dry to obtain a photosensitive polymer. The molar ratio of monomer A, monomer B and monomer C is about 66.5:8.5:25. The structural formula of the photosensitive polymer finally prepared is where x 1 :y 1 :z 1 =66.5:8.5:25; its weight average molecular weight (Mw) is 22,000; and its polydispersity index (PDI) is 2.1.

[0085] Monomer A: Monomer B: Monomer C:

[0086] 4. Use of Photoresist Composition

[0087] The photoresist composition was filtered through a 0.2 μm membrane filter to prepare a photoresist solution. Next, the photoresist solution was spin-coated onto a silicon wafer to produce a 10-μm thick film photoresist. After pre-baking at 110°C, the film was exposed to 248 nm ultraviolet light through a photomask, followed by a post-exposure bake at 120°C. Development was then performed using a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 23°C for 1 minute. The resin compatibility and pattern shape were observed.

[0088] 5. Photoacid generator Examples 1 to 5 and Comparative Examples 1 to 10 are shown in the following table

[0089]

[0090]

[0091] The structure of C1-C10 is as follows:

[0092]

[0093]

[0094] 6. Effects of Photoacid Generators and Corresponding Photoresist Compositions

[0095]

[0096]

Claims

1. A KrF thick film photoresist composition, characterized in that It includes a photoacid generator as shown in formula I; In formula I, n is 0, 1, 2 or 3; R1 is -COOR 1-1 or C 1-4 Alkyl; R 1-1 C 1-4 alkyl; R2 is C 1-4 alkyl; The KrF thick film photoresist composition comprises: a photosensitive polymer, triethanolamine, a solvent and a photoacid generator of formula I; The photosensitive polymer is a photosensitive polymer obtained by addition polymerization of monomer A, monomer B and monomer C, wherein the monomer A is The monomer B is The monomer C is The molar ratio of the monomer A, the monomer B and the monomer C is 66.5:8.5:

25.

2. The KrF thick film photoresist composition according to claim 1, wherein The photoacid generator satisfies one or more of the following conditions: (1) n is 0, 1 or 2; (2) When R1 is -COOR 1-1 When the R 1-1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl; (3) When R1 is C 1-4 When alkyl, R1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl; (4) R2 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.

3. The KrF thick film photoresist composition according to claim 2, wherein The photoacid generator satisfies one or more of the following conditions: (1) When R1 is -COOR 1-1 When the R 1-1 Ethyl; (2) When R1 is C 1-4 When alkyl, the R1 is methyl; (3) R2 is methyl.

4. The KrF thick film photoresist composition according to claim 2, wherein The photoacid generator is any one of the following compounds:

5. The KrF thick film photoresist composition according to claim 1, wherein The photoacid generator is composed of the photoacid generator, the photosensitive polymer, triethanolamine and a solvent.

6. The KrF thick film photoresist composition according to claim 5, wherein It meets one or more of the following conditions: (1) The weight average molecular weight of the photosensitive polymer is 10,000 to 600,000; (2) The polydispersity coefficient of the photosensitive polymer is 1 to 3; (3) The solvent is an ester solvent; (4) The weight of the photosensitive polymer is 100 parts; (5) The weight portion of the photoacid generator is 5 parts, based on 100 parts by weight of the photosensitive polymer; (6) The weight portion of the triethanolamine is 0.1 parts, based on 100 parts by weight of the photosensitive polymer; (7) The weight portion of the solvent is 800 parts based on 100 parts by weight of the photosensitive polymer.

7. The KrF thick film photoresist composition according to claim 6, wherein It meets one or more of the following conditions: (1) The weight average molecular weight of the photosensitive polymer is 20,000 to 400,000; (2) The polydispersity coefficient of the photosensitive polymer is 2.1; (3) The solvent is propylene glycol monomethyl ether acetate.

8. The KrF thick film photoresist composition according to claim 7, wherein The weight average molecular weight of the photosensitive polymer is 22,000.

9. The KrF thick film photoresist composition according to claim 6, wherein The photosensitive polymer is prepared by dissolving 5 parts by weight of the photoacid generator, 100 parts by weight of the photosensitive polymer, and 0.1 parts by weight of triethanolamine in 800 parts by weight of propylene glycol monomethyl ether acetate; wherein the photosensitive polymer is obtained by subjecting the monomer A, the monomer B, and the monomer C to an addition polymerization reaction; the molar ratio of the monomer A, the monomer B, and the monomer C is 66.5:8.5:25; the weight average molecular weight of the finally prepared photosensitive polymer is 22,000; and the polydispersity index thereof is 2.

1.

10. The KrF thick film photoresist composition according to any one of claims 6 to 9, characterized in that: It meets one or more of the following conditions: (1) The solvent for the polyaddition reaction is an ester solvent; (2) The temperature of the addition polymerization reaction is 75-80°C; (3) The polyaddition reaction time is 6 to 10 hours; (4) After the polyaddition reaction is completed, the following post-treatment steps are performed: 1) the reaction solution is mixed with an alcohol solvent to produce a precipitate, and the precipitate is mixed with an ester solvent to dissolve it; 2) the operation in step 1) is repeated three times, and the mixture is mixed with an alcohol solvent to obtain a precipitate, which is then dried.

11. The KrF thick film photoresist composition according to claim 10, wherein It meets one or more of the following conditions: (1) The solvent for the polyaddition reaction is ethyl acetate; (2) The temperature of the addition polymerization reaction is 78°C; (3) The time of the polyaddition reaction is 8 hours; (4) In the post-treatment step, the alcohol solvent is methanol; (5) In the post-treatment step, the ester solvent is ethyl acetate.

12. The KrF thick film photoresist composition according to any one of claims 5 to 9, wherein The preparation method comprises the following steps: uniformly mixing the photoacid generator, the photosensitive polymer, the triethanolamine and the solvent.

13. The KrF thick film photoresist composition according to claim 12, wherein In the method for preparing the KrF thick film photoresist composition, after the mixing is completed, filtering is performed; the filtration is performed using a filter; the pore size of the filter membrane of the filter is 150 to 250 nm.

14. The KrF thick film photoresist composition according to claim 13, wherein In the method for preparing the KrF thick film photoresist composition, the filter membrane pore size is 200 nm.

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