WO2023097826A1 - Krf light source thick film photoresist composition, preparation method therefor and use method thereof - Google Patents

Abstract

Disclosed are a KrF light source thick film photoresist composition, a preparation method therefor and a use method thereof. Specifically, disclosed are a KrF thick film photoresist composition containing a photo-acid generator represented by formula (I), a preparation method therefor and a use method thereof. Photoresist film formed from the photoresist composition has good rectangularity.

Description

KrF light source thick film photoresist composition, its preparation method and its use method

This application claims the priority of Chinese patent applications 2021114487874, 2021114445250 and 2021114444173 with the filing date of November 30, 2021. This application cites the full text of the above-mentioned Chinese patent application.

technical field

The invention relates to a KrF light source thick-film photoresist composition, a preparation method and a use method thereof.

Background technique

At present, in the field of semiconductor manufacturing, KrF light source thick-film photoresist is used in the chip manufacturing process of LCD (liquid crystal display) / BUMP bump / MEMS micro-electromechanical / 3D-NAND memory. This type of photoresist is different from conventional The KrF thin-layer photoresist is also different from the photoresist of the ArF light source, but has its own unique properties.

Although integrated circuit semiconductor chip manufacturing technology is developing rapidly, the technology of thick-film photoresist for this kind of KrF light source is not fully mature, which is a hot field of research on KrF photoresist.

Contents of the invention

The invention provides a kind of KrF thick-film photoresist composition, it comprises the photoacid generator 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 is C _1-4 alkyl;

R ₂ is C _1-4 alkyl.

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

In a preferred embodiment, R ₁ is -COOR ^1-1 , wherein R ^1-1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl , preferably ethyl.

In a preferred embodiment, R is _methyl , ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, preferably methyl.

In a preferred embodiment, R is _methyl , ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, preferably methyl.

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

In the present invention, the KrF thick film photoresist composition includes the following components: the photoacid generator, photosensitive polymer, triethanolamine and solvent.

The photosensitive polymer may be a polymer capable of photochemically reacting with deep ultraviolet (DUV) light. For example, the photopolymer may be a polymer that undergoes a chemical reaction when a photoacid generator (PAG) mixed with the photopolymer is exposed to light, such as deep ultraviolet light, to generate an acid, and the acid thus generated renders the polymer A chemical reaction is performed to make the polymer either hydrophilic or hydrophobic. It will be appreciated that the photopolymer does not have to be directly sensitive to light (e.g., exposure of the photopolymer to light need not alter the chemical composition of the photopolymer, although the chemical composition of the photopolymer can acid produced by PAG). In some embodiments, the solubility of photopolymers in bases can be increased due to photochemical reactions. In some embodiments, the photopolymer may have a structure in which a protecting group is bonded to a repeating unit, and the protecting group may be deprotected during exposure, so that the photopolymer is well soluble in alkali. The photoresist may be a positive-tone photoresist, where portions of the photoresist removed by subsequent photoresist development are exposed to light (eg, DUV light). Deprotected protecting groups can generate new acids for chemical amplification.

The photosensitive polymer can be phenolic resin, polyhydroxystyrene resin, acrylic resin or a combination thereof.

Described phenolic resin can be the resin that has the repeating unit shown in formula (IV),

In formula (IV), R ^5a is an acid-dissociated protecting group, and each of R ^5b and R ^5c is a hydrogen atom or a C ₁ -C ₆ alkyl group. R ^5a is C ₁ -C ₆ linear, branched or cyclic alkyl, vinyloxyethyl, tetrahydropyranyl, tetrahydrofuryl, trialkylsilyl, iso-norbornyl, 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-tetrahydrofuryl, 2,3-propylene carbonate-1-yl, 1-methoxyethyl, 1-ethoxyethyl, 1-(2-methoxyethoxy)ethyl, 1-(2-acetoxyethoxy)ethyl, tert-butoxy ylcarbonylmethyl, methoxymethyl, ethoxymethyl, trimethoxysilyl or triethoxysilyl, and may be methoxyethyl, ethoxyethyl, n-propoxy oxyethyl, isopropoxyethyl, n-butoxyethyl, isobutoxyethyl, tert-butoxyethyl, cyclohexyloxyethyl, methoxypropyl, ethoxypropyl , 1-methoxy-1-methyl-ethyl, 1-ethoxy-1-methylethyl, tert-butoxycarbonyl (t-BOC) or tert-butoxycarbonylmethyl. The linear or branched alkyl group may include, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl or neopentyl. The cyclic alkyl group may include, for example, cyclopentyl or cyclohexyl.

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

In formula (V), R ^7a is a hydrogen atom or a C _1-6 alkyl group, and R ^7b is an acid-dissociated protecting group. The definition of the acid-dissociated protecting group is as described above.

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, such as 2-methacryloyloxyethylsuccinic acid, 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid and 2 - methacryloxyethyl hexahydrophthalic acid; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate and butyl (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; diesters of dicarboxylic acids such as diethyl maleate and dibutyl fumarate; vinyl-containing aromatic compounds such as styrene, alpha-methylstyrene, chlorobenzene Ethylene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene and α-ethylhydroxystyrene; vinyl-containing aliphatic compounds 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. Compounds such as acrylamide and methacrylamide.

The acrylic resin may be a resin having a repeating unit shown in formula (VI);

(VI);

In formula (VI), R ^8a is a hydrogen atom, a C ₁ -C ₆ linear or branched alkyl group, a fluorine atom or a C ₁ -C ₆ linear or branched fluorinated alkyl group, and R ^8b is an acid Dissociated protecting group. The definition of the acid-dissociated protecting group is as described above.

In a certain embodiment of the KrF thick film photoresist composition, the photosensitive polymer may comprise 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(tert-butyl methacrylate ), poly(methacrylic acid), poly(norbornyl methacrylate), binary or terpolymer photopolymers of repeating units of the above-mentioned (meth)acrylate-based polymers, or combinations thereof.

The acrylic resin may include another polymerizable compound as a repeating unit. Examples of the polymerizable compound may include, but are not limited to: acrylates having ether linkages, such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (methyl ) Methoxytriethylene glycol acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, ( Methoxypolyethylene glycol methacrylate, methoxypolypropylene glycol (meth)acrylate and tetrahydrofurfuryl (meth)acrylate; monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; di Carboxylic acids, such as maleic acid, fumaric acid and itaconic acid; methacrylic acid derivatives with carboxyl groups and ester bonds, such as 2-methacryloyloxyethylsuccinic acid, 2-methacryloyloxy 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylhexahydrophthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid; alkyl (meth)acrylates such as (meth) ) methyl acrylate, ethyl (meth)acrylate, butyl (meth)acrylate and cyclohexyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate esters and 2-hydroxypropyl (meth)acrylate; aryl (meth)acrylates, such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters, such as dimaleic acid Ethyl esters and dibutyl fumarate; vinyl-containing aromatic compounds such as styrene, alpha-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, alpha-formaldehyde hydroxystyrene 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; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; and amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

In a certain embodiment of the KrF thick film photoresist composition, the photosensitive polymer may have the following structure:

Where x ¹ :y ¹ :z ¹ =66.5:8.5:25.

The photosensitive polymer can be obtained through conventional polyaddition reactions in the art. In a certain embodiment of the photoresist composition, the photosensitive polymer can be obtained by carrying out polyaddition reaction of monomer A, monomer B and monomer C, and the 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,

In a certain embodiment, the solvent for the polyaddition reaction is an ester solvent, preferably ethyl acetate.

In a certain embodiment, the temperature of the polyaddition reaction is 75-80°C, preferably 78°C.

In a certain embodiment, the time of the polyaddition reaction is 6-10 hours, preferably 8 hours.

In a certain embodiment, after the polyaddition reaction is completed, it can be processed through the following post-treatment steps: 1) mixing the reaction solution with an alcohol solvent to produce a precipitate, mixing the precipitate with an ester solvent, and dissolving; 2) Repeat 1) operation 3 times, then mix with alcohol solvent to obtain precipitate, then dry it.

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

In the post-processing step, the ester solvent is preferably ethyl acetate.

In a certain 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; and for example, 22,000. Here, the Mw value may be a value measured using gel permeation chromatography (GPC) by setting polystyrene as a standard.

In a certain embodiment of the KrF thick film photoresist composition, the photopolymer may have a polydispersity index (PDI) of 1 to 3, for example 2.1.

In a certain embodiment, the preparation method of the photosensitive polymer is as follows:

(1) Add about 80g of monomer A, about 9g of monomer B and about 32g of monomer C into a reaction kettle filled with nitrogen, then add 110g of ethyl acetate into the reaction kettle, stir well and raise the temperature of the reaction kettle to 78°C , then in the reaction kettle, dropwise add the mixed solution of ethyl acetate (25g) and benzoyl peroxide (2.2g), dropwise in 10 minutes. React at 78° C. for 8 hours, stop the reaction, and cool the temperature of the reaction solution to room temperature; (2) then add methanol (1000 g) to the reaction kettle to generate a precipitate. After 1h, derive the liquid in the reactor, add ethyl acetate (150g) to the precipitate and dissolve in the reactor; (3) repeat the operation of step (2) 3 times, then add methanol (1000g) in the reactor to obtain The solid precipitate was placed in a vacuum drying oven to dry to obtain a photosensitive polymer. Wherein, 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

Wherein x ¹ :y ¹ :z ¹ =66.5:8.5:25; its weight average molecular weight (Mw) is 22000; its polydispersity index (PDI) is 2.1.

Described KrF thick-film photoresist composition, described solvent is the conventional solvent of this type of reaction in this area, is preferably ester solvent, such as propylene glycol monomethyl ether acetate.

For the KrF thick film photoresist composition, the photosensitive polymer has 100 parts by weight.

For the KrF thick film photoresist composition, the photoacid generator has 5 parts by weight.

In the KrF thick film photoresist composition, the weight part of the triethanolamine is 0.1 part.

For the KrF thick film photoresist composition, the solvent has 800 parts by weight.

In a preferred embodiment of the present invention, the KrF thick film photoresist composition is composed of the above-mentioned photoacid generator, the above-mentioned photosensitive polymer, the above-mentioned triethanolamine and the above-mentioned solvent.

The "above" in the above-mentioned photoacid generator includes types and parts by weight; the "above" in the above-mentioned photosensitive polymers includes types and parts by weight; the "above" in the above-mentioned triethanolamine includes parts by weight; "Above" includes types and parts by weight.

In a preferred embodiment of the present invention, the KrF thick-film photoresist composition is dissolved to 800 wt. parts by weight of the aforementioned photoacid generator, 100 wt. Parts of propylene glycol monomethyl ether acetate are prepared; wherein, the photosensitive polymer is obtained by carrying out polyaddition reaction of the monomer A, the monomer B and the monomer C; the polyaddition reaction The conditions and operations 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 photosensitive polymer finally prepared is was 22,000; its polydispersity index (PDI) was 2.1.

The present invention also provides an application of the aforementioned compound represented by formula I as a photoacid generator in KrF thick film photoresist.

The present invention also provides a preparation method of the above-mentioned KrF thick-film photoresist composition, which includes the following steps: uniformly mixing the above-mentioned photoacid generator, the above-mentioned photosensitive polymer, the above-mentioned triethanolamine and the above-mentioned solvent.

The "above" in the above-mentioned photoacid generator includes types and parts by weight; the "above" in the above-mentioned photosensitive polymers includes types and parts by weight; the "above" in the above-mentioned triethanolamine includes parts by weight; "Above" includes types and parts by weight.

The mixing is a conventional operation in the art. Wherein, the temperature of the mixing is room temperature.

After the mixing is completed, the operation of filtering may also be included. The filtering method is a conventional filtering method in the field, preferably using a filter, and the filter membrane pore size of the filter is preferably 150nm-250nm, more preferably 200nm.

The present invention also provides a kind of using method of above-mentioned KrF thick film photoresist composition, described method comprises the steps:

Step 1: coating the above-mentioned KrF thick film photoresist composition on the surface of the substrate to form a photoresist layer;

Step 2: Pre-baking the photoresist layer;

Step 3: Copy the pattern on the mask plate to the pre-baked photoresist layer by exposure;

Step 4: Baking the exposed photoresist layer;

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

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

In step 1, the coating method is preferably spin coating;

In step 1, the thickness of the composition layer is preferably 8.5-11.5 μm, more preferably 10 μm;

In step 2, the temperature of the pre-baking is preferably 95-125°C, more preferably 110°C;

In step 3, the wavelength of the exposure is preferably 248nm;

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

In step 5, the developer is preferably an aqueous solution of tetramethylammonium hydroxide, for example, an aqueous solution of tetramethylammonium hydroxide with a mass percentage of 2.38%;

In step 5, the developing temperature is preferably 20-25°C, more preferably 23°C;

In step 5, the developing time is preferably 0.5-2 min, more preferably 1 min.

On the basis of not violating common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention.

The reagents and raw materials used in the present invention are all commercially available.

The positive progress effect of the present invention lies in that the photoresist film obtained by the method has good rectangularity.

Detailed ways

The present invention is further illustrated below by means of examples, but the present invention is not limited to the scope of the examples. For the experimental methods that do not specify specific conditions in the following examples, select according to conventional methods and conditions, or according to the product instructions.

1. Photoacid generation function test of photoacid generator

Adjust the acetonitrile solution of photoacid generator to a concentration of 0.05mol/L, put it into a quartz optical cell with an optical path length of 1cm, irradiate the light (290nm) separated by a xenon lamp, and measure the radiation of acid generation. Use the absorption of tetrabromophenol blue at 610nm to observe the amount of acid produced. The amount of light was measured using potassium ferrite trioxalate to obtain the quantum yield.

2. Solubility test of photoacid generator

Weigh 1.0 g of photoacid generator, add it to 100 g of propylene glycol methyl ether acetate, stir it magnetically for 20 minutes, and observe the solubility.

3. Photoresist Composition Preparation

5 parts by weight of photoacid generator, 100 parts by weight of photosensitive polymer, and 0.1 part by weight of triethanolamine were dissolved into 800 parts by weight of propylene glycol monomethyl ether acetate, and mixed uniformly to prepare a photoresist composition.

Wherein, the preparation method of photosensitive polymer is as follows:

(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 raise the temperature of the reactor to 78°C , then in the reaction kettle, dropwise add the mixed solution of ethyl acetate (25g) and benzoyl peroxide (2.2g), dropwise in 10 minutes. React at 78° C. for 8 hours, stop the reaction, and cool the temperature of the reaction solution to room temperature; (2) then add methanol (1000 g) to the reaction kettle to generate a precipitate. After 1h, derive the liquid in the reactor, add ethyl acetate (150g) to the precipitate and dissolve in the reactor; (3) repeat the operation of step (2) 3 times, then add methanol (1000g) in the reactor to obtain The solid precipitate was placed in a vacuum drying oven to dry to obtain a photosensitive polymer. Wherein, 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

Wherein x ¹ :y ¹ :z ¹ =66.5:8.5:25; its weight average molecular weight (Mw) is 22,000; its polydispersity index (PDI) is 2.1.

Monomer A:

Monomer B:

Monomer C:

4. Use of Photoresist Composition

The photoresist composition was filtered with a 0.2 μm membrane filter to prepare a photoresist solution. Next, a photoresist solution was spin-coated on the silicon wafer to prepare a thick-film photoresist with a thickness of 10 microns. After pre-baking at 110°C, exposure to 248nm ultraviolet rays through a photomask, followed by post-exposure baking at 120°C. Then, image development was performed at 23 degreeC for 1 minute with the 2.38weight% tetramethylammonium hydroxide aqueous solution. Observe resin compatibility and pattern shape.

5. Photoacid Generator Examples 1-5 and Comparative Examples 1-10 are shown in Table 1

Table 1

Example/Comparative example	Types of photoacid generators
Example 1	A1
Example 2	A2
Example 3	A3
Example 4	A4
Example 5	A5
Comparative example 1	C1

Comparative example 2	C2
Comparative example 3	C3
Comparative example 4	C4
Comparative example 5	C5
Comparative example 6	C6
Comparative example 7	C7
Comparative example 8	C8
Comparative example 9	C9
Comparative example 10	C10

The structure of C1-C10 is as follows:

6. Effects of photoacid generators and corresponding photoresist compositions are shown in Table 2. Table 2

Effect example	quantum yield	Solubility	resin compatibility	pattern shape
Example 1	0.2	completely dissolved	good	clear rectangle
Example 2	0.25	completely dissolved	good	clear rectangle
Example 3	0.2	completely dissolved	good	clear rectangle
Example 4	0.24	completely dissolved	good	clear rectangle
Example 5	0.24	completely dissolved	good	clear rectangle
Comparative example 1	0.16	incompletely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 2	0.18	incompletely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 3	0.19	incompletely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 4	0.21	completely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 5	0.22	completely dissolved	good	Slightly enlarged shape of the head
Comparative example 6	0.21	completely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 7	0.15	completely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 8	0.23	completely dissolved	slightly worse	Slightly enlarged shape of the head
Comparative example 9	0.19	completely dissolved	slightly worse	Slightly enlarged shape of the head

Comparative example 10

0.15

completely dissolved

good

Slightly enlarged shape of the head

.

Although the specific implementations of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or changes can be made to these implementations without departing from the principle and essence of the present invention. Revise. Accordingly, the protection scope of the present invention is defined by the appended claims.

Claims (12)

1. A KrF thick-film photoresist composition is characterized in that it includes a photoacid generator as shown in formula I;

   

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

   R ₁ is -COOR ^1-1 or C _1-4 alkyl; R ^1-1 is C _1-4 alkyl;

   R ₂ is C _1-4 alkyl.
2. KrF thick film photoresist composition as claimed in claim 1, is characterized in that, described photoacid generator satisfies one or more of following conditions:

   (1) n is 0, 1 or 2;

   (2) When R ₁ is -COOR ^1-1 , said R ^1-1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl base, preferably ethyl;

   (3) When R ₁ is C _1-4 alkyl, said R ₁ is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl , preferably methyl;

   (4) R ₂ is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, preferably methyl.
3. KrF thick film photoresist composition as claimed in claim 1, is characterized in that, described photoacid generator is any one of following compound:

   

   
4. KrF thick film photoresist composition as described in any one of claim 1-3, it is characterized in that, it comprises photosensitive polymer, triethanolamine, solvent and photogenerator as described in any one of claim 1-3 acid agent; the photosensitive polymer is phenolic resin, polyhydroxystyrene resin, acrylic resin or a combination thereof.
5. KrF thick film photoresist composition as claimed in claim 4, is characterized in that, it satisfies one or more of following conditions:

   (1) The photosensitive polymer is a photosensitive polymer obtained by addition polymerization of monomer A, monomer B and monomer C, and the described 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 weight average molecular weight of the photosensitive polymer is 10,000 to 600,000; for example, 20,000 to 400,000; another example is 22,000;

   (3) The polydispersity coefficient of the photosensitive polymer is 1 to 3, such as 2.1;

   (4) The solvent described is an ester solvent, such as propylene glycol monomethyl ether acetate;

   (5) The parts by weight of the photosensitive polymer is 100 parts;

   (6) The parts by weight of the photoacid generator are 5 parts;

   (7) the parts by weight of described triethanolamine is 0.1 part;

   (8) The parts by weight of the solvent is 800 parts.
6. KrF thick film photoresist composition as claimed in claim 5, is characterized in that, it satisfies one or more of following conditions:

   (1) The solvent of the polyaddition reaction is an ester solvent, preferably ethyl acetate;

   (2) The temperature of the polyaddition reaction is 75 to 80°C, preferably 78°C;

   (3) The time of the polyaddition reaction is 6 to 10 hours, preferably 8 hours;

   (4) After the end of the polyaddition reaction, the following post-processing steps are carried out: 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; 2) Repeat 1) operation 3 times, and then mixed with an alcohol solvent to obtain a precipitate, which can be dried; the alcohol solvent is preferably methanol; the ester solvent is preferably ethyl acetate.
7. The KrF thick film photoresist composition according to claim 6, characterized in that it consists of said photoacid generator, said photosensitive polymer, said triethanolamine and said solvent.
8. KrF thick film photoresist composition as claimed in claim 7, is characterized in that, it is dissolved by the triethanolamine described in 5 parts by weight of photoacid generator, photosensitive polymer described in 100 parts by weight, 0.1 part by weight to 800 parts by weight of propylene glycol monomethyl ether acetate; wherein, the photosensitive polymer is carried out by addition polymerization of the monomer A, the monomer B and the monomer C The reaction is obtained; 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 of the photosensitive polymer finally prepared is 22000; its polydispersity The sex index is 2.1.
9. An application of a compound as shown in formula I as a photoacid generator in KrF thick film photoresist.
10. A preparation method of the KrF thick film photoresist composition as described in any one of claims 1-8, is characterized in that, each component of described KrF thick film photoresist composition is mixed homogeneously ; Preferably, after the mixing is completed, filter; the filter is used for filtering; the pore size of the filter membrane is 150-250nm, preferably 200nm.
11. A method for using the KrF thick film photoresist composition as described in any one of claims 1-8, is characterized in that, it comprises the steps:

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

    Step 2: Pre-baking the photoresist layer;

    Step 3: Copy the pattern on the mask plate to the pre-baked photoresist layer by exposure;

    Step 4: Baking the exposed photoresist layer;

    Step 5: Apply a developer to the baked photoresist layer for development to obtain a photoresist pattern.
12. The method of use according to claim 11, wherein it satisfies one or more of the following conditions:

    (1) In step 1, the substrate is a silicon wafer;

    (2) In step 1, the mode of described coating is spin coating;

    (3) In step 1, the thickness of the photoresist layer is 8.5-11.5 μm, preferably 10 μm;

    (4) In step 2, the temperature of the pre-baking is 95-125°C, preferably 110°C;

    (5) In step 3, the wavelength of the exposure is 248nm;

    (6) In step 4, the baking temperature is 110-130°C, preferably 120°C;

    (7) In step 5, the developer is an aqueous solution of tetramethylammonium hydroxide, such as an aqueous solution of tetramethylammonium hydroxide with a mass percentage of 2.38%;

    (8) In step 5, the developing temperature is 20-25°C, preferably 23°C;

    (9) In step 5, the developing time is 0.5-2 min, preferably 1 min.