Method for producing phenolic hydroxyl group-containing ethylenically unsaturated compound

Abstract

It is possible to provide a method for producing a phenolic hydroxyl group-containing ethylenically unsaturated compound for obtaining an industrially advantageous material in a more excellent yield.SOLUTION: The method for producing a phenolic hydroxyl group-containing ethylenically unsaturated compound of the present disclosure is a method of reacting a compound (a) with an unsaturated monocarboxylic acid or an anhydride thereof (b) in the presence of a solvent and a catalyst. The compound (a) is a compound having a phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms. The catalyst is phosphoric acid.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group. [Background technology]

[0002] Hydroxyphenyl (meth)acrylate, which has a phenolic hydroxyl group, can be easily introduced into the polymer by copolymerization, and the resulting polymer exhibits good properties as a positive resist resin, so it is widely used in semiconductor applications, display applications, etc. One of the challenges with hydroxyphenyl (meth)acrylate is improving the yield due to the influence of impurities such as dimers that are produced as by-products. For example, Patent Document 1 discloses a method for producing hydroxyphenyl(meth)acrylate, which comprises the steps of reacting a dihydric phenol with (meth)acrylic acid in the presence of methanesulfonic acid under a reduced pressure of 20 kPa to 65 kPa (absolute pressure) to prepare a reaction solution containing hydroxyphenyl(meth)acrylate and a by-product, phenylenedi(meth)acrylate, and adding an aliphatic hydrocarbon solvent to the reaction solution to prepare crude crystals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-14694 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for a method for producing an industrially advantageous material with improved yield, as well as a method for producing a material that can provide a better pattern shape as a positive resist resin. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a manufacturing method for obtaining industrially advantageous materials with a higher yield. [Means for solving the problem]

[0005] The present invention includes the following aspects. [1] A method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group, comprising reacting a compound (a) with an unsaturated monocarboxylic acid or an anhydride thereof (b) in the presence of a solvent and a catalyst, the compound (a) is a compound having a phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms, The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group, wherein the catalyst is phosphoric acid. [2] The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to [1], wherein the compound (a) is a compound having one phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms. [3] The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to [1] or [2], wherein the unsaturated monocarboxylic acid or anhydride thereof (b) is (meth)acrylic anhydride. [4] The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to any one of [1] to [3], wherein the solvent is a glycol ether solvent. [5] A method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to any one of [1] to [4], wherein the reaction is carried out under a temperature condition of 50 to 120°C. [6] The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to any one of [1] to [5], wherein the reaction is carried out for 1 to 15 hours. [7] relative to the total number of moles of the compound (a), the unsaturated monocarboxylic acid or anhydride thereof (b), the reaction product of the phenolic hydroxyl group-containing ethylenically unsaturated compound, and the reaction product of the di-substituted compound of the compound (a), The method for producing a phenolic hydroxyl group-containing ethylenically unsaturated compound according to any one of claims [1] to [6], wherein the content of the phenolic hydroxyl group-containing ethylenically unsaturated compound in the reaction liquid after the reaction is 50 mol% or more. [8] relative to the total number of moles of the compound (a), the unsaturated monocarboxylic acid or anhydride thereof (b), the reaction product of the phenolic hydroxyl group-containing ethylenically unsaturated compound, and the reaction product of the di-substituted compound of the compound (a), The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to any one of [1] to [7], wherein the content of the disubstituted compound of the compound (a) in the reaction liquid after the reaction is 15 mol % or less. [9] A purification step of washing the reaction solution with water after the reaction is completed to precipitate a phenolic hydroxyl group-containing ethylenically unsaturated compound, The method for producing a phenolic hydroxyl group-containing ethylenically unsaturated compound according to any one of [1] to [8], wherein the isolated yield of the phenolic hydroxyl group-containing ethylenically unsaturated compound is 30 mol % or more relative to the theoretical yield when the reaction rate is 100 mol %. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a manufacturing method for obtaining industrially advantageous materials with a better yield. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the embodiments described below.

[0008] In this specification, when "~" is used to describe a numerical range, the numerical values ​​at both ends are the upper and lower limits, respectively, and are included in the numerical range. When multiple upper or lower limits are listed, numerical ranges can be created using all combinations of the upper and lower limits. Similarly, when multiple numerical ranges are listed, separate numerical ranges can be created by individually selecting and combining upper and lower limits from those numerical ranges.

[0009] In this specification, "(meth)acrylic acid" means methacrylic acid or acrylic acid, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyloxy" means acryloyloxy or methacryloyloxy. In this specification, "(poly)alkylene glycol" means alkylene glycol or polyalkylene glycol.

[0010] In this specification, the term "ethylenically unsaturated bond" refers to a double bond formed between carbon atoms excluding carbon atoms forming an aromatic ring, the term "ethylenically unsaturated group" refers to a group having an ethylenically unsaturated bond, and the term "ethylenically unsaturated compound" refers to a compound having an ethylenically unsaturated bond.

[0011] (Method for producing phenolic hydroxyl group-containing ethylenically unsaturated compounds) In one embodiment, a method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group comprises reacting a compound (a) having a phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms (hereinafter simply referred to as "compound (a)") with an unsaturated monocarboxylic acid or an anhydride thereof (b) in the presence of a solvent and a catalyst, wherein the catalyst is phosphoric acid.

[0012] [Compound (a)] The compound (a) is a compound having a phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms. The compound (a) may be of only one type, or of two or more types. By using the compound (a), an ethylenically unsaturated group can be preferentially introduced into the hydroxyalkyl group having 1 to 6 carbon atoms, so that the phenolic hydroxyl group can be efficiently preserved and the production of a by-product in which the ethylenically unsaturated group is introduced into the phenolic hydroxyl group side can be suppressed. As a result, a phenolic hydroxyl group-containing ethylenically unsaturated compound can be obtained in high yield.

[0013] From the viewpoints of controlling the reaction with the unsaturated monocarboxylic acid or its anhydride (b) and preventing a decrease in yield due to the generation of by-products, and of facilitating control of solubility, developability, and pattern shape when used as a resist material, the compound (a) is preferably a compound having one phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms. The number of carbon atoms in the alkanediyl group of compound (a) is 1 to 6, preferably 1 to 3, and more preferably 2 to 3. The compound (a) is preferably a compound represented by the following formula (1). [ka] (In formula (1), R 1 R is an alkanediyl group having 1 to 6 carbon atoms, some of the carbon atoms of which may be substituted with an ether bond or an ester bond. 2 is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms; a is 1 or 2; and b is an integer of 0 to 4, provided that 1≦a+b≦5.

[0014] In the formula (1), R 1 R is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 1 to 3 carbon atoms, and even more preferably an alkanediyl group having 2 or 3 carbon atoms. 1 Examples of R include an ethanediyl group and a propanediyl group. 1 is preferably a saturated hydrocarbyl group having 1 to 6 carbon atoms, more preferably a saturated hydrocarbyl group having 1 to 2 carbon atoms. a is preferably 1, and OH is more preferably at the 4-position, i.e., the para-position. b is preferably 0 to 2, and more preferably 0. R 2 is preferably at the 3rd or 5th position, i.e., the meta position.

[0015] Specific examples of the compound (a) include hydroxyphenylmethanol, hydroxyphenylethanol, hydroxyphenylpropanol, and 4-hydroxy-3,5-dimethylphenylmethanol. Among these, hydroxyphenylmethanol, hydroxyphenylethanol, and hydroxyphenylpropanol are preferred, with hydroxyphenylethanol being more preferred. In particular, 4-hydroxyphenylmethanol, 2-(4-hydroxyphenyl)ethanol (p-hydroxyphenethyl alcohol), and 3-(4-hydroxyphenyl)propanol are preferred, with 2-(4-hydroxyphenyl)ethanol (p-hydroxyphenethyl alcohol) being more preferred.

[0016] [Unsaturated monocarboxylic acid or its anhydride (b)] The unsaturated monocarboxylic acid or its anhydride (b) is a monocarboxylic acid or its anhydride having an ethylenically unsaturated group. The unsaturated monocarboxylic acid or its anhydride (b) may be one type or two or more types. By using the unsaturated monocarboxylic acid or its anhydride (b), an ethylenically unsaturated group can be introduced into the compound (a). Therefore, by using the resulting compound as a polymerizable monomer, a resin having an introduced phenolic hydroxyl group can be synthesized.

[0017] Specific examples of unsaturated monocarboxylic acids include unsaturated carboxylic acids such as (meth)acrylic acid, α-bromo(meth)acrylic acid, β-furyl(meth)acrylic acid, crotonic acid, isocrotonic acid, tiglic acid, cinnamic acid, and α-cyanocinnamic acid; and monoesters of unsaturated dicarboxylic acids and alcohols having 1 to 8 carbon atoms, such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate. Among these, α,β-unsaturated monocarboxylic acids are preferred from the viewpoint of reactivity as a polymerizable monomer. From the viewpoints of reaction control with compound (a) and the yield of the target product, the unsaturated monocarboxylic acid or its anhydride (b) is preferably an anhydride of an unsaturated monocarboxylic acid, more preferably (meth)acrylic acid or (meth)acrylic anhydride, and even more preferably (meth)acrylic anhydride.

[0018] [Phenol-hydroxyl-containing ethylenically unsaturated compounds] The phenolic hydroxyl group-containing ethylenically unsaturated compound is a compound formed by esterification of the hydroxyalkyl group of compound (a) with the carboxylic acid moiety of an unsaturated monocarboxylic acid or its anhydride (b). Because compound (a) has a hydroxyalkyl group, the unsaturated monocarboxylic acid or its anhydride (b) reacts preferentially with the phenolic hydroxyl group of compound (a), thereby suppressing the generation of by-products and improving the yield of the target product. Furthermore, because the phenolic hydroxyl group-containing ethylenically unsaturated compound has an alkanediyl group, when a resin synthesized using this compound is used as a resist material, high light transmittance is ensured, and a cured product with excellent pattern shape can be obtained.

[0019] The phenolic hydroxyl group-containing ethylenically unsaturated compound is preferably a compound represented by the following formula (2):

[0020] [ka] (In formula (2), R A is a hydrogen atom or a methyl group. 1 , R 2 , a, and b are the same as in formula (2), except that 1≦a+b≦5.

[0021] Examples of the phenolic hydroxyl group-containing ethylenically unsaturated compound include hydroxyphenylmethyl (meth)acrylate, hydroxyphenylethyl (meth)acrylate, hydroxyphenylpropyl (meth)acrylate, 3,5-dimethyl-hydroxyphenylmethyl (meth)acrylate, etc. Among these, hydroxyphenylmethyl (meth)acrylate, hydroxyphenylethyl (meth)acrylate, and hydroxyphenylpropyl (meth)acrylate are preferred, and hydroxyphenylethyl (meth)acrylate is more preferred.

[0022] [catalyst] The catalyst is phosphoric acid. The use of phosphoric acid moderately inhibits the esterification reaction between the phenolic hydroxyl group and the unsaturated monocarboxylic acid or its anhydride (b), allowing the esterification reaction between the hydroxyalkyl group of compound (a) and the unsaturated monocarboxylic acid or its anhydride (b) to proceed preferentially, thereby enabling the production of a phenolic hydroxyl group-containing ethylenically unsaturated compound in good yield. When a strong acid commonly used in esterification reactions is used, its activity in the esterification reaction is too high, and it also promotes the esterification reaction between the phenolic hydroxyl group and the unsaturated monocarboxylic acid or its anhydride (b), thereby promoting the production of by-products and reducing the yield of the phenolic hydroxyl group-containing ethylenically unsaturated compound.

[0023] [solvent] The solvent is not particularly limited as long as it is inert to the compound (a) and the unsaturated monocarboxylic acid or its anhydride (b) and can dissolve the compound (a) and the unsaturated monocarboxylic acid or its anhydride (b).

[0024] The solvent is preferably a glycol ether solvent from the viewpoint of the solubility of the compound (a) and the unsaturated monocarboxylic acid or its anhydride (b). Specific examples include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether. These solvents may be used alone or in combination of two or more. Among these, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol diethyl ether are preferred from the viewpoints of availability and reactivity. Specific examples of other solvents include (poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, and ethoxypropionate. Examples of the ester include esters such as ethyl acetoacetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-butyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutyrate; and aromatic hydrocarbons such as toluene and xylene.

[0025] [Proportion of each ingredient] The amount of unsaturated monocarboxylic acid or its anhydride (b) is preferably 30 to 200 mol%, more preferably 50 to 150 mol%, and even more preferably 80 to 105 mol%, based on the number of moles of compound (a). A blending amount of unsaturated monocarboxylic acid or its anhydride (b) of 30 mol% or more is preferred because it can reduce the content of compound (a) remaining unreacted during the reaction. A blending amount of unsaturated monocarboxylic acid or its anhydride (b) of 200 mol% or less is preferred because it can suppress the esterification reaction between the phenolic hydroxyl group of compound (a) and unsaturated monocarboxylic acid or its anhydride (b).

[0026] The amount of catalyst is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, and even more preferably 1 to 2.5 parts by mass, relative to 100 parts by mass of the total of compound (a) and unsaturated monocarboxylic acid or its anhydride (b). When the amount of catalyst is 0.1 part by mass or more, the esterification reaction proceeds at a sufficient rate. When the amount of catalyst is 5 parts by mass or less, the esterification reaction between the phenolic hydroxyl group of compound (a) and unsaturated monocarboxylic acid or its anhydride (b) can be suppressed, which is preferable.

[0027] The amount of solvent blended is preferably 30 to 200 parts by mass, more preferably 40 to 150 parts by mass, and even more preferably 40 to 100 parts by mass, per 100 parts by mass of the total of compound (a) and unsaturated monocarboxylic acid or its anhydride (b). When the amount of solvent blended is 30 parts by mass or more, the concentration of each component raw material is good, and the generation of by-products can be suppressed with good reproducibility. When the amount of solvent blended is 200 parts by mass or less, the efficiency of the subsequent purification process can be easily improved.

[0028] [Reaction conditions] The temperature condition during the reaction of compound (a) with unsaturated monocarboxylic acid or its anhydride (b) is preferably 50 to 120°C, more preferably 70 to 110°C, and even more preferably 80 to 100°C. When the temperature condition is 50°C or higher, the esterification reaction proceeds at a sufficient reaction rate. When the temperature condition is 120°C or lower, side reactions such as the esterification reaction between the phenolic hydroxyl group of compound (a) and the unsaturated monocarboxylic acid or its anhydride (b) and dimerization of the phenolic hydroxyl group-containing ethylenically unsaturated compound can be suppressed. The reaction time of the compound (a) and the unsaturated monocarboxylic acid or its anhydride (b) is preferably 1 to 20 hours, more preferably 3 to 15 hours, and even more preferably 5 to 10 hours. When the reaction time is 1 hour or more, a sufficient reaction rate can be ensured. When the reaction time is 20 hours or less, unintended side reactions can be suppressed.

[0029] The reaction atmosphere between the compound (a) and the unsaturated monocarboxylic acid or its anhydride (b) may be, for example, an air atmosphere. The reaction pressure of the compound (a) and the unsaturated monocarboxylic acid or its anhydride (b) may be, for example, atmospheric pressure.

[0030] [Reaction product content] According to the production method of the present invention, an ethylenically unsaturated compound containing a phenolic hydroxyl group can be obtained in high yield. For example, the content of the phenolic hydroxyl group-containing ethylenically unsaturated compound in the reaction solution after the reaction is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 65 mol% or more, based on the total number of moles of the compound (a), the unsaturated monocarboxylic acid or anhydride thereof (b), the phenolic hydroxyl group-containing ethylenically unsaturated compound as a reaction product, and the di-substituted product of the compound (a) as a reaction product in which an ethylenically unsaturated group has also been introduced into the phenolic hydroxyl group. The isolated yield of the phenolic hydroxyl group-containing ethylenically unsaturated compound is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more, relative to the theoretical yield when the reaction rate is 100 mol%. The upper limit of the isolated yield may be 90 mol% or less, 80 mol% or less, or 70 mol% or less.

[0031] The production method of the present invention can suppress the formation of by-products such as disubstituted phenolic hydroxyl group-containing ethylenically unsaturated compounds. The content of the di-substituted phenolic hydroxyl group-containing ethylenically unsaturated compound in the reaction solution after the reaction is preferably 15 mol % or less, more preferably 10 mol % or less, and even more preferably 5 mol % or less, based on the total number of moles of the compound (a), the unsaturated monocarboxylic acid or anhydride thereof (b), the reaction product of the phenolic hydroxyl group-containing ethylenically unsaturated compound, and the di-substituted compound of the compound (a), which is a reaction product in which an ethylenically unsaturated group has also been introduced into the phenolic hydroxyl group.

[0032] [Refining process] The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to the present embodiment may further include a purification step of washing the reaction solution with water after completion of the reaction to precipitate the ethylenically unsaturated compound containing a phenolic hydroxyl group. In the purification step, for example, water is added to the reaction solution after the reaction, and after stirring, the aqueous layer is removed. By repeating this operation 4 to 6 times, the raw materials (compound (a), unsaturated monocarboxylic acid or its anhydride (b), solvent, and catalyst) are removed along with the aqueous layer, and a white solid is precipitated. Toluene is added to the precipitated white solid, and the mixture is heated to 80°C to dissolve the white solid. Hexane is added to the solution, and the mixture is cooled to room temperature, whereupon a white solid is precipitated. By removing the liquid phase, the disubstituted product is removed, and the target product is obtained.

[0033] [Uses of phenolic hydroxyl group-containing ethylenically unsaturated compounds] The phenolic hydroxyl group-containing ethylenically unsaturated compound produced by the production method of this embodiment can be used as a monomer for the resin (RA) contained in, for example, a positive resist material.

[0034] <Positive resist materials> The positive resist material contains a resin (RA) and a photoacid generator (B). The resin (RA) is a copolymer containing a structural unit (a-1) represented by the following formula (2) and a structural unit (a-2) represented by the following formula (2). The resin (RA) may further contain another structural unit (a-3) as necessary. The positive resist material may also contain a solvent (C). The phenolic hydroxyl group-containing ethylenically unsaturated compound can be used as a monomer that provides the structural unit (a-1).

[0035] [Resin (RA)] Resin (RA) is a copolymer containing a structural unit (a-1) represented by the following formula (2) and a structural unit (a-2) represented by the following formula (2). Resin (RA) (the copolymer) may further contain another structural unit (a-3) as necessary.

[0036] [ka]

[0037] (In formula (2), R A is a hydrogen atom or a methyl group. 1 R is an alkanediyl group having 1 to 6 carbon atoms, some of the carbon atoms of which may be substituted with an ether bond or an ester bond. 2 is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms; a is 1 or 2; and b is an integer of 0 to 4, provided that 1≦a+b≦5.

[0038] [ka]

[0039] (In formula (3), R B is a hydrogen atom or a methyl group. 4 is an acid labile group.

[0040] The weight-average molecular weight (Mw) of the resin (RA) is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more. The weight-average molecular weight of the resin (RA) is preferably 50,000 or less, more preferably 30,000 or less, and even more preferably 25,000 or less. When the weight-average molecular weight of the resin (RA) is 5,000 or more, it is possible to prevent the high-energy ray unexposed portion of the resist from dissolving during alkaline washing. When the weight-average molecular weight of the resin (RA) is 50,000 or less, the high-energy ray exposed portion of the resist has good alkaline solubility.

[0041] The molecular weight distribution (Mw / Mn) of the resin (RA) is preferably 1.1 or more, more preferably 1.5 or more, and even more preferably 1.7 or more. The molecular weight distribution (Mw / Mn) of the resin (RA) is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 2.0 or less. When the molecular weight distribution (Mw / Mn) of the resin (RA) is 1.1 or more, it is easy to control the production conditions during synthesis of the resin (RA). When the molecular weight distribution (Mw / Mn) of the resin (RA) is 5.0 or less, it is possible to suppress variations in alkali solubility due to variations in the molecular weight distribution of the polymer.

[0042] In this specification, the weight average molecular weight (Mw) and number average molecular weight (Mn) are values ​​measured using gel permeation chromatography (GPC) under the following conditions and determined using a standard polystyrene calibration curve. Column: Two Showdex (trademark) LF-804 (Resonac Inc.) columns were used connected in series. Column temperature: 40℃ Sample: 0.2% by mass solution of the object to be measured in tetrahydrofuran Developing solvent: tetrahydrofuran Detector: Differential refractometer (Shodex (trademark) RI-71S) (Resonac Co., Ltd.) Flow rate: 1mL / min

[0043] The content of resin (RA) in the positive resist material is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total of resin (RA) and solvent (C). The content of resin (RA) is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total of resin (RA) and solvent (C). When the content of resin (RA) is within the above range, the resist has an appropriate viscosity, improving workability when applied to a wafer.

[0044] "Structural unit (a-1) represented by formula (2)" The structural unit (a-1) is a structural unit represented by formula (2). The structural unit (a-1) may be of one type, or of two or more types. When the resin (RA) contains the structural unit (a-1), the positive resist material has good energy ray transmittance, and a cured product having a good pattern shape can be obtained. In the formula (2), R 1 is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably an alkanediyl group having 1 to 3 carbon atoms, and even more preferably an alkanediyl group having 2 to 3 carbon atoms. 1 Examples of R include an ethanediyl group and a propanediyl group. 2 is preferably a saturated hydrocarbyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group. In the formula (2), at least a portion of the H atoms of the phenolic hydroxyl groups contained in the resin (RA) may be replaced with acid labile groups. The amount of replacement is not particularly limited, but the ratio (molar ratio) of the amount of phenolic hydroxyl groups to the amount of acid labile groups contained in the resin (RA) may be 50:50 to 90:10, 60:40 to 90:10, or 60:40 to 80:20. By replacing at least a portion of the H atoms of the phenolic hydroxyl groups with acid labile groups, the solubility of unexposed areas during development of the cured resin film can be further reduced, thereby reducing unintended dissolution and film loss. a is preferably 1, and OH is more preferably at the 4-position, i.e., the para-position. b is preferably 0 to 2, and more preferably 0. R 2 is preferably at the 3rd or 5th position, i.e., the meta position.

[0045] The phenolic hydroxyl group-containing ethylenically unsaturated compound, which is the monomer that provides the structural unit (a-1), can be the phenolic hydroxyl group-containing ethylenically unsaturated compound synthesized by the production method of this embodiment described above.

[0046] [Acid-labile group] The "acid labile group" of the present disclosure is not particularly limited as long as it is a substituent that can be eliminated by reacting with an acid generated by an acid generator described below. Examples of the acid labile group include those described in JP-A Nos. 2013-80033 and 2013-83821. The acid labile groups may be selected from a variety of groups, which may be the same or different, and particularly include those represented by the following formulae (A-1) to (A-3). Among these, those represented by the following formulae (A-1) or (A-3) are preferred.

[0047] [ka]

[0048] In formula (A-1), R 30represents a tertiary alkyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, each alkyl group being a trialkylsilyl group having 1 to 6 carbon atoms, an oxoalkyl group having 4 to 20 carbon atoms, or a group represented by the above general formula (A-3). Specific examples of the tertiary alkyl group include a tert-butyl group, a tert-amyl group, a 1,1-diethylpropyl group, a 1-ethylcyclopentyl group, a 1-butylcyclopentyl group, a 1-ethylcyclohexyl group, a 1-butylcyclohexyl group, a 1- Examples of the oxoalkyl group include a 3-oxocyclohexyl group, a 4-methyl-2-oxooxan-4-yl group, a 5-methyl-2-oxooxolan-5-yl group, etc. n1 is an integer of 0 to 6.

[0049] In formula (A-2), R 31 , R 32 R represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a cyclopentyl group, a cyclohexyl group, a 2-ethylhexyl group, an n-octyl group, etc. 33 represents a monovalent hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10, which may have a heteroatom such as an oxygen atom, and examples thereof include linear, branched, and cyclic alkyl groups, as well as those in which some of the hydrogen atoms have been substituted with hydroxyl groups, alkoxy groups, oxo groups, amino groups, alkylamino groups, etc., and specific examples include the following substituted alkyl groups.

[0050] [ka]

[0051] R 31 and R 32 , R 31 and R 33 , R32 and R 33 may be bonded to form a ring together with the carbon atom to which they are bonded, and when a ring is formed, R 31 , R 32 , R 33 represents a linear or branched alkylene group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and the ring preferably has 3 to 10 carbon atoms, particularly preferably 4 to 10 carbon atoms.

[0052] Specific examples of the acid labile group represented by the above formula (A-1) include a tert-butoxycarbonyl group, a tert-butoxycarbonylmethyl group, a tert-amyloxycarbonyl group, a tert-amyloxycarbonylmethyl group, a 1,1-diethylpropyloxycarbonyl group, a 1,1-diethylpropyloxycarbonylmethyl group, a 1-ethylcyclopentyloxycarbonyl group, a 1-ethylcyclopentyloxycarbonylmethyl group, a 1-ethyl-2-cyclopentenyloxycarbonyl group, a 1-ethyl-2-cyclopentenyloxycarbonylmethyl group, a 1-ethoxyethoxycarbonylmethyl group, a 2-tetrahydropyranyloxycarbonylmethyl group, and a 2-tetrahydrofuranyloxycarbonylmethyl group.

[0053] Further examples include substituents represented by the following formulae (A-1)-1 to (A-1)-10.

[0054] [ka] where R 37 are the same or different linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms, or aryl groups having 6 to 20 carbon atoms; R 38 is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. 39 are the same or different, and are linear, branched or cyclic alkyl groups having 2 to 10 carbon atoms, or aryl groups having 6 to 20 carbon atoms. n1 is as defined above.

[0055] Of the acid labile groups represented by the above formula (A-2), examples of linear or branched groups include those represented by the following formulae (A-2)-1 to (A-2)-15.

[0056] [ka]

[0057] Next, R of the acid labile group represented by formula (A-3) 34 , R 35 , R 36 is a monovalent hydrocarbon group such as a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a linear, branched or cyclic alkenyl group having 2 to 20 carbon atoms, which may contain a heteroatom such as oxygen, sulfur, nitrogen or fluorine; R 34 and R 35 , R 34 and R 36 , R 35 and R 36 may be bonded to each other to form an alicyclic ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.

[0058] Examples of the tertiary alkyl group of the acid labile group represented by formula (A-3) include a tert-butyl group, a triethylcarbyl group, a 1-ethylnorbornyl group, a 1-methylcyclohexyl group, a 1-ethylcyclopentyl group, a 2-(2-methyl)adamantyl group, a 2-(2-ethyl)adamantyl group, and a tert-amyl group.

[0059] The content of the structural unit (a-1) in the structural units of the resin (RA) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more. The content of the structural unit (a-1) in the structural units of the resin (RA) is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. When the content of the structural unit (a-1) is 30 mol% or more, the dry etching resistance of the resist is good. When the content of the structural unit (a-1) is 90 mol% or less, the proportion of (a-2) in the structural units of the resin (RA) is sufficient, and the alkali solubility of the high-energy ray-exposed areas of the resist is good.

[0060] "Structural unit (a-2) represented by formula (2)" The structural unit (a-2) is a structural unit represented by formula (2). The structural unit (a-2) may be of one type, or of two or more types. When the resin (RA) contains the structural unit (a-2), the developability of the positive resist material is good, and a cured product having a good pattern shape can be obtained.

[0061] Examples of monomers that provide the structural unit (a-2) include, but are not limited to, those shown below. B and R 4 is the same as above.

[0062] [ka]

[0063] Examples of the acid labile group include those described in JP-A Nos. 2013-80033 and 2013-83821. The acid labile groups may be selected from various groups, which may be the same or different, and particularly include those represented by the above formulae (A-1) to (A-3). Among these, those represented by the above formulae (A-1) and (A-3) are preferred. Preferred examples of formulae (A-1) to (A-3) are the same as those described above in [Acid Labile Group].

[0064] The content of the structural unit (a-2) in the structural units of the resin (RA) is preferably 1 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more. The content of the structural unit (a-1) in the structural units of the resin (RA) is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less. When the content of the structural unit (a-2) is 1 mol% or more, the alkali solubility of the high-energy ray exposed areas of the resist is good. When the content of the structural unit (a-2) is 40 mol% or less, the proportion of (a-1) in the structural units of the resin (RA) is sufficient, and the dry etching resistance of the resist is good.

[0065] "Other structural units (a-3)" Examples of the other structural unit (a-3) include aromatic vinyl compounds, aromatic allyl compounds, vinyl carboxylates, dienes, (meth)acrylic acid esters, vinyl compounds, unsaturated dicarboxylic acid diesters, monomaleimides, etc. The other structural unit (a-3) is a structural unit that does not belong to the structural unit (a-1) or the structural unit (a-2).

[0066] Specific examples of aromatic vinyl compounds include styrene, α-methylstyrene, α-chloromethylstyrene, vinyltoluene, and divinylbenzene.

[0067] Specific examples of the aromatic allyl compound include diallyl phthalate and diallyl benzene phosphonate.

[0068] Specific examples of vinyl carboxylate include vinyl carboxylates such as vinyl acetate and vinyl adipate.

[0069] Examples of dienes include butadiene, isoprene, and chloroprene. Examples of (meth)acrylic acid esters include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, pentyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, and cyclohexyl (meth)acrylate; 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(2-hydroxyethoxy)ethyl (meth)acrylate, (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(2-hydroxyethoxy)ethyl ... p) 2-[2-[2-(2-hydroxyethoxy)ethoxy]ethoxy]ethyl acrylate, hexaethylene glycol mono(meth)acrylate, octaethylene glycol mono(meth)acrylate, rosin (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, and the like.

[0070] Examples of the vinyl compound include vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, vinyl acetate, and vinyltoluene.

[0071] Examples of the unsaturated dicarboxylic acid diester include diethyl citraconate, diethyl maleate, diethyl fumarate, and diethyl itaconate.

[0072] Examples of monomaleimides include N-phenylmaleimide, N-cyclohexylmaleimide, and N-laurylmaleimide.

[0073] The content of the structural unit (a-3) in the structural units of the resin (RA) is preferably 40 mol% or less, more preferably 30 mol% or less, and even more preferably 20 mol% or less. The content of the structural unit (a-3) in the structural units of the resin (RA) may be 1 mol% or more, 5 mol% or more, or 10 mol% or more. If the content of the structural unit (a-2) is 40 mol% or more, the proportions of (a-1) and (a-2) in the structural units of the resin (RA) decrease, and the etching resistance of the resist and the alkali solubility of areas exposed to high-energy rays deteriorate. Of all the structural units constituting the resin (RA), it is preferred that the structural unit (a-1) represented by the above formula (2) accounts for 30 to 90 mol %, the structural unit (a-2) represented by the above formula (2) accounts for 1 to 40 mol %, and the other structural unit (a-3) accounts for 0 to 40 mol %. Of all the structural units constituting the resin (RA), it is more preferred that the structural unit (a-1) represented by the above formula (2) accounts for 40 to 80 mol %, the structural unit (a-2) represented by the above formula (2) accounts for 10 to 35 mol %, and the other structural unit (a-3) accounts for 5 to 30 mol %. Of all the structural units constituting the resin (RA), it is even more preferred that the structural unit (a-1) represented by the above formula (2) accounts for 50 to 70 mol %, the structural unit (a-2) represented by the above formula (2) accounts for 15 to 30 mol %, and the other structural unit (a-3) accounts for 10 to 25 mol %.

[0074] <Resin (RA) manufacturing method> In one embodiment, the resin (RA) can be produced by copolymerizing the monomer (ma-1), the monomer (ma-2), and, if necessary, another monomer (ma-3). The proportions of the structural units (a-1), (a-2), and (a-3) contained in the copolymer are the same as the proportions of the respective monomers (ma-1), (ma-2), and (ma-3) in the total of all the monomers used as raw materials for the copolymer. The phenolic hydroxyl group-containing ethylenically unsaturated compound produced by the production method of this embodiment can be used as the monomer (ma-1).

[0075] The proportions of the monomers used in the copolymerization reaction to form the copolymer precursor are not particularly limited. Preferably, the proportions are 30 to 90 mol% of the monomer (ma-1), 1 to 40 mol% of the monomer (ma-2), and 0 to 40 mol% of the monomer (ma-3), more preferably 40 to 80 mol% of the monomer (ma-1), 10 to 35 mol% of the monomer (ma-2), and 5 to 30 mol% of the monomer (ma-3), and even more preferably 50 to 70 mol% of the monomer (ma-1), 15 to 30 mol% of the monomer (ma-2), and 10 to 25 mol% of the monomer (ma-3).

[0076] The copolymerization reaction can be carried out in the presence or absence of a solvent according to a radical polymerization method known in the art. For example, the above-mentioned monomers may be dissolved in an organic solvent, a polymerization initiator may be added to the solution, and the polymerization reaction may be carried out at 50 to 100°C for 1 to 20 hours.

[0077] The solvent used in the copolymerization reaction can be the same as the solvent (C) described below. Other examples include hydroxyl group-containing organic solvents such as propylene glycol monoaryl ether, 1,3-propanediol monoalkyl ether, 1,3-butanediol monoalkyl ether, 1,4-butanediol monoalkyl ether, glycerin monoalkyl ether, glycerin dialkyl ether, methanol, ethanol, propanol, C5-6 cycloalkanediol, C5-6 cycloalkane dimethanol, ethyl lactate, and diacetone alcohol. The term "C5-6 cycloalkane" refers to a cycloalkyl group having 5 to 6 carbon atoms. The copolymerization reaction is preferably carried out in the presence of a hydroxyl group-containing organic solvent to prevent abnormal polymerization and ensure stable polymerization. The solvents may be used alone or in combination of two or more.

[0078] The polymerization initiator that can be used in the copolymerization reaction is not particularly limited, but examples thereof include azobisisobutyronitrile, azobisisovaleronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, and t-butylperoxy-2-ethylhexanoate. The polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator used is generally 0.5 to 20 parts by mass, and preferably 1.0 to 18 parts by mass, per 100 parts by mass of the total amount of monomers charged.

[0079] [Photoacid generator (B)] The positive resist material of the present disclosure contains an acid generator (hereinafter also referred to as an additive-type acid generator) that generates a strong acid. The strong acid here refers to a compound that has sufficient acidity to cause a deprotection reaction of the acid labile groups of the base polymer.

[0080] Examples of the acid generator include compounds (photoacid generators) that generate acid in response to actinic rays or radiation. The photoacid generator is not particularly limited as long as it generates an acid upon exposure to high-energy rays, but preferred are those that generate sulfonic acid, imide acid, or methide acid. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate-type acid generators. Specific examples of photoacid generators include those described in paragraphs

[0122] to

[0142] of JP 2008-111103 A.

[0081] Furthermore, as the photoacid generator, a sulfonium salt represented by the following formula (2-1) or an iodonium salt represented by the following formula (2-2) can also be suitably used. [ka]

[0082] In formulas (2-1) and (2-2), R 101 ~R 105are each independently a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. R 101 ~R 105 Specific examples of the hydrocarbyl group having 1 to 20 carbon atoms represented by the following formula include those described in paragraphs

[0154] to

[0156] of JP-A No. 2024-010654. Examples of the cation of the sulfonium salt represented by formula (2-1) include those described in paragraphs

[0157] to

[0180] of JP-A No. 2024-010654. Examples of the cation of the iodonium salt represented by formula (2-2) include those described in paragraphs

[0181] to

[0182] of JP-A No. 2024-010654. In formulas (2-1) and (2-2), Xa - Examples of such compounds include those described in paragraphs

[0183] to

[0196] of JP 2024-010654 A.

[0083] Moreover, as the photoacid generator, an onium salt having high solubility in a suitable solvent is preferred. Specific examples of onium salts include diazonium salts, ammonium salts, iodonium salts, sulfonium salts, phosphonium salts, and oxonium salts. Specific examples include diphenyliodonium triflate, diphenyliodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, and (hydroxyphenyl)benzylmethylsulfonium toluenesulfonate. Commercially available products include the CPI-210 series and IK-1 series (San-Apro Co., Ltd.), which are suitable for use. These thermal acid generators and photoacid generators may be used alone or in combination of two or more.

[0084] The content of the photoacid generator (B) is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 3 parts by mass or more, based on 100 parts by mass of the resin (RA). The content of the photoacid generator (B) is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the resin (RA). When the content of the photoacid generator (B) is 0.1 parts by mass or more, the alkali solubility of the high-energy ray exposed portion of the resist is good. When the content of the photoacid generator (B) is 30 mol % or less, sufficient solubility in the solvent (C) and affinity with the developer are ensured.

[0085] [Solvent (C)] Examples of the solvent (C) include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether and diethylene glycol mono-n-butyl ether, propylene glycol monoalkyl ethers such as triethylene glycol monomethyl ether, propylene glycol monomethyl ether and propylene glycol monoethyl ether, dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, tripropylene glycol monoalkyl ethers such as tripropylene glycol monoethyl ether, and (poly)alkylene glycol monoalkyl ethers such as 3-methoxy-1-butanol; hydroxy group-containing carboxylic acid esters such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl hydroxyacetate, and methyl 2-hydroxy-3-methylbutyrate; and diethylene glycol ethanol and other hydroxyl group-containing organic solvents; and (poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; methyl ethyl ketone, cyclohexanone, Ketones such as 2-heptanone and 3-heptanone; esters such as methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl ethoxyacetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-butyl acetate, i-propyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutyrate;Examples of the solvent (D) include hydroxyl-free organic solvents such as aromatic hydrocarbons such as toluene and xylene. The solvent (D) may be used alone or in combination of two or more kinds.

[0086] Among these solvents (C), it is preferable to use a compound having an ether structure from the viewpoints of availability, cost, and stability during resist preparation. Specifically, it is more preferable to use at least one selected from propylene glycol monomethyl ether acetate, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, and 3-methoxy-1-butanol.

[0087] [Other ingredients] In addition to the above-mentioned components, the positive resist material of the present invention may also contain a surfactant, a dissolution inhibitor, a crosslinking agent, a quencher other than the onium salt of the present invention (hereinafter referred to as "other quenchers"), a water repellency improver, acetylene alcohols, etc.

[0088] <Method for manufacturing positive resist material> The positive resist material can be produced by a method of mixing a resin (RA), a photoacid generator (B), and a solvent (C) using a known mixing device. The positive resist material of one embodiment can be produced by a method of mixing a resin (RA), a photoacid generator (B), and a solvent (C) using a known mixing device.

[0089] When producing a positive resist material, the reaction solution used to produce the resin (RA) can be used as is as a raw material. In this case, the solvent contained in the reaction solution can be used as part or all of the solvent (C) contained in the positive resist material.

[0090] When producing a positive resist material, the resin (RA) may be isolated from a reaction solution containing the resin (RA) by a known method and used as a raw material.

[0091] <Cured resin film> The cured resin film is a cured product of the positive resist material. The cured resin film can be formed, for example, by applying a liquid containing the positive resist material to form a film, and then evaporating the solvent using a hot plate or the like.

[0092] (Pattern formation method) When the positive resist material is used in the manufacture of various integrated circuits, known lithography techniques can be applied. For example, the pattern formation method of the present invention includes the steps of forming a resist film on a substrate using the positive resist material (chemically amplified resist material), exposing the resist film to high-energy rays, and developing the exposed resist film using a developer.

[0093] An example of the pattern forming method of the present invention will be described below.

[0094] First, the positive resist material is applied to a substrate for integrated circuit manufacturing (e.g., Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coating, etc.) or a substrate for mask circuit manufacturing (e.g., Cr, CrO, CrON, MoSi2, SiO2, etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., to a coating thickness of 0.01 to 10 μm. This is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[0095] Next, the resist film is exposed to high-energy radiation. Examples of the high-energy radiation include ultraviolet radiation, far ultraviolet radiation, electron beam (EB), extreme ultraviolet radiation (EUV) with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When ultraviolet radiation, far ultraviolet radiation, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation are used as the high-energy radiation, the exposure dose is preferably 1 to 500 mJ / cm, either directly or using a mask for forming a desired pattern. 2 approximately, more preferably 10 to 300 mJ / cm 2 The exposure dose is preferably about 0.1 to 300 μC / cm2, more preferably about 0.5 to 200 μC / cm2, and is conducted directly or using a mask to form the desired pattern. The positive resist material is particularly suitable for fine patterning using high-energy beams such as KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation, and is particularly suitable for fine patterning using KrF excimer laser light, ArF excimer laser light, EB, or EUV with a wavelength of 3 to 15 nm.

[0096] After exposure, PEB may or may not be performed on a hot plate or in an oven, preferably at 30 to 150° C. for 10 seconds to 30 minutes, more preferably at 50 to 120° C. for 30 seconds to 20 minutes.

[0097] After exposure or PEB, the exposed resist film is developed using a developer of 0.1 to 10% by weight, preferably 2 to 5% by weight, of an aqueous alkaline solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by a conventional method such as dipping, puddling, or spraying, to form the desired pattern. In the case of a positive resist material, the irradiated portion dissolves in the developer, while the unexposed portion remains insoluble, forming the desired positive pattern on the substrate. In the case of a negative resist material, the opposite occurs: the irradiated portion becomes insoluble in the developer, while the unexposed portion dissolves.

[0098] A negative pattern can also be obtained by organic solvent development using a positive resist material containing a base polymer containing an acid labile group. Examples of developers used in this case include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, and ethyl crotonate. Examples of organic solvents include methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, and 2-phenylethyl acetate. These organic solvents may be used alone or in combination of two or more.

[0099] After the development is completed, it is preferable to rinse the resist film. As the rinse liquid, a solvent that is miscible with the developer but does not dissolve the resist film is preferable. As such a solvent, for example, an alcohol having 3 to 10 carbon atoms, an ether compound having 8 to 12 carbon atoms, an alkane, alkene, alkyne, or aromatic solvent having 6 to 12 carbon atoms is preferably used.

[0100] Examples of the alcohol having 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, and 3-hexanol. Examples of the alcohol include 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, and 1-octanol.

[0101] Examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-pentyl ether, and di-n-hexyl ether.

[0102] Examples of the alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Examples of the alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of the alkynes having 6 to 12 carbon atoms include hexyne, heptine, and octyne.

[0103] Examples of the aromatic solvent include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0104] Rinsing can reduce the occurrence of resist pattern collapse and defects. Rinsing is not always necessary, and not performing rinsing can reduce the amount of solvent used.

[0105] The developed hole or trench pattern can also be shrunk using thermal flow, RELACS, or DSA. A shrink agent is applied to the hole pattern, and the diffusion of an acid catalyst from the resist film during baking causes crosslinking of the shrink agent on the surface of the resist film, resulting in adhesion of the shrink agent to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is preferably 10 to 300 seconds. Excess shrink agent is removed, and the hole pattern is shrunk. [Example]

[0106] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0107] [Example 1] A flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube was charged with 100.0 g (47.26 parts by mass) of p-hydroxyphenethyl alcohol, 111.6 g (52.74 parts by mass) of methacrylic anhydride, and 150.0 g (71 parts by mass) of diethylene glycol dimethyl ether, and the temperature was raised to 65°C. Next, 5.0 g (1.18 parts by mass) of 75% phosphoric acid was added, and the temperature was raised to 80°C. After 2 hours, 5.0 g (1.18 parts by mass) of 75% phosphoric acid was added, and the temperature was raised to 90°C. The mixture was stirred for 7 hours after the initial addition of phosphoric acid to obtain a reaction solution. Then, 300 g (142 parts by mass) of distilled water was added to the reaction solution, and after stirring, the aqueous layer was removed. 150 g (71 parts by mass) of toluene was added to the precipitated white solid, and the temperature was raised to 80°C to dissolve the white solid. Adding 150 g (71 parts by mass) of hexane to the above solution and cooling to room temperature yielded 79 g (37 parts by mass) of the target compound A1 (4-hydroxyphenylethyl methacrylate). The isolated yield calculated from the amount present after the reaction was 53 mol%. The molar ratio of each product relative to 100 mol of the amount present after the reaction is shown in Table 1.

[0108] [Examples 2 to 5, Comparative Examples 1 to 4] In Examples 2 to 5 and Comparative Examples 1 to 4, the target compounds A2 to A6 and cA1 to cA4 were obtained in the same manner as in Example 1 using the amounts of raw materials, catalysts, and solvents used, the reaction temperature, and the reaction time shown in Table 1.

[0109] [Table 1]

[0110] A reference synthesis example of the resin (RA) and a reference example of a positive resist material using the same are shown below. [Raw materials] 4-Hydroxyphenylethyl methacrylate (Compound (A) synthesized in Example 1) t-Butyl acrylate (Osaka Organic Chemical Industry Co., Ltd.) 1-Ethylcyclopentyl (meth)acrylate (Tokyo Chemical Industry Co., Ltd.) 1-Ethylcyclohexyl (meth)acrylate (Tokyo Chemical Industry Co., Ltd.) 2-Methyl-2-adamantyl methacrylate (Tokyo Chemical Industry Co., Ltd.) Styrene (Idemitsu Kosan) 2,2'-Azobis(2-methylpropionate)dimethyl (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0111] [Reference synthesis example 1] 80 g of propylene glycol monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed as solvent (C) in a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer, and a gas inlet tube, and the mixture was stirred while replacing with nitrogen gas and heated to 90°C.

[0112] Next, 73 g (60 mol%) of 4-hydroxyphenylethyl methacrylate synthesized in Example 1 as monomer (ma-1), 12 g (20 mol%) of tert-butyl acrylate as monomer (ma-2), 15 g (20 mol%) of styrene as monomer (ma-3), 20 g (20 parts by mass relative to 100 parts by mass of the total of the monomer components) of propylene glycol monomethyl ether as solvent (C), and 2.5 g (2.5 parts by mass relative to 100 parts by mass of the total of the monomer components) of 2,2'-azobis(2-methylpropionate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator were mixed to prepare a raw material monomer solution.

[0113] The entire amount of the raw material monomer solution prepared was added dropwise over 2 hours using a dropping funnel to solvent (C) in a flask under a nitrogen gas atmosphere at normal pressure. After the addition was completed, the solution in the flask was cooled to 85°C while stirring, and a polymerization reaction was carried out for 4 hours to obtain a liquid containing copolymer (RA) and solvent (C). The weight average molecular weight and molecular weight distribution of copolymer (RA) were measured using the methods described above and are listed in Table 2.

[0114] [Comparative Reference Synthesis Examples 1-2] Liquids containing copolymers (cRA) of Comparative Reference Synthesis Examples 1 and 2 were obtained using the raw materials and blending ratios shown in Table 2 in the same manner as in Reference Synthesis Example 1. The weight average molecular weight and molecular weight distribution of each copolymer (cRA) were measured by the methods described above and are shown in Table 2.

[0115] [Table 2]

[0116] In Table 2, the meanings of the abbreviations are as follows: 2HPEM: 2-hydroxyphenylethyl methacrylate 4HSt: 4-hydroxystyrene 4HPM: 4-hydroxyphenyl methacrylate BA: t-butyl acrylate St: styrene APDM: 2,2'-azobis(2-methylpropionate) dimethyl ester

[0117] [Reference example 1, comparative reference examples 1-2] The copolymer (RA) of Reference Synthesis Example 1 or the copolymer (cRA) of Comparative Reference Synthesis Examples 1 and 2 shown in Table 3, CPI-210S (manufactured by San-Apro) as the photoacid generator (B), and propylene glycol monomethyl ether (PGME) as the solvent (C) were mixed in the proportions shown in Table 3 to prepare the positive resist materials of Reference Example 1 and Comparative Reference Examples 1 and 2. The blending amount of copolymer (RA) or (cRA) shown in Table 3 does not include the amount of solvent. The concentrations shown in Table 3 indicate the content of copolymer (RA) relative to the total of copolymer (RA) and solvent (C) in the positive resist material.

[0118] (film thickness measurement) The positive resist materials of Reference Example 1 and Comparative Reference Examples 1 and 2 were spin-coated onto a 6-inch silicon wafer (manufactured by Shin-Etsu Chemical Co., Ltd.) to form a coating film with a thickness of 2 μm after pre-baking. The coating film was then heated at 90°C for 90 seconds to volatilize and remove the solvent (C). The thickness of the resist film was measured using a step gauge. The results are shown in Tables 3 and 4.

[0119] (KrF light transmittance measurement) The positive resist materials of Reference Example 1 and Comparative Reference Examples 1 and 2 were spin-coated onto a square, non-alkali glass substrate measuring 5 cm in length and 5 cm in width in plan view to form a coating film with a thickness of 3 μm after exposure. The substrate was then heated at 90°C for 90 seconds to volatilize and remove the solvent (C) in the coating film. The resist film was measured using a spectrophotometer to measure the transmittance at 248 nm, which corresponds to KrF light. The results are shown in Table 3.

[0120] (Pattern shape evaluation) The pattern shape was evaluated by measuring Eop and Bottom CD.

[0121] "Creating patterned samples" The positive resist materials of Reference Example 1 and Comparative Reference Examples 1 and 2 were applied by spin coating onto a 6-inch silicon wafer (manufactured by Shin-Etsu Chemical Co., Ltd.) to form a coating film with a thickness of 2 μm after pre-baking. The coating film was then heated at 90° C. for 90 seconds to volatilize and remove the solvent (C) in the coating film.

[0122] "Eop measurement" The resist film was exposed using a KrF stepper (FPA 300-EX5, Canon). The wafer was baked (PEB) on a hot plate at 90°C for 90 seconds and then puddle-developed with a 2.38% by weight TMAH aqueous solution for 60 seconds. The resulting resist pattern was observed using a CD-SEM S9200 (Hitachi High-Tech). The exposure dose required to form a 16 nm line / 32 nm pitch (line and space (L / S = 1 / 1)) was defined as the optimal exposure dose, and the exposure dose at this time was defined as Eop. The results are shown in Table 3.

[0123] "Bottom CD measurement" The resist film was exposed to light at a dose of 300 mJ / cm 2Exposure was performed using a KrF stepper (FPA 300-EX5, Canon) to obtain a wafer with a thickness of approximately 2,000 nm. The wafer was then baked (PEB) on a hot plate at 90°C for 90 seconds, and puddle-developed with a 2.38% by mass TMAH aqueous solution for 60 seconds. The resist pattern, masked so that the bottom of the resist pattern was approximately 2,000 nm, was confirmed using a CD-SEM S9200 (Hitachi High-Tech). The bottom CD of the resist pattern was measured, and its length was taken as the bottom CD. The results are shown in Table 3.

[0124] [Table 3]

Claims

1. A method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group, comprising reacting a compound (a) with an unsaturated monocarboxylic acid or an anhydride thereof (b) in the presence of a solvent and a catalyst, the compound (a) is a compound having a phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms, The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group, wherein the catalyst is phosphoric acid.

2. 2. The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to claim 1, wherein the compound (a) is a compound having one phenolic hydroxyl group and one hydroxyalkyl group having 1 to 6 carbon atoms.

3. 2. The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to claim 1, wherein the unsaturated monocarboxylic acid or anhydride thereof (b) is (meth)acrylic anhydride.

4. The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to claim 1, wherein the solvent is a glycol ether solvent.

5. The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to claim 1, wherein the reaction is carried out under a temperature condition of 50 to 120°C.

6. The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to claim 1, wherein the reaction is carried out for 1 to 15 hours.

7. relative to the total number of moles of the compound (a), the unsaturated monocarboxylic acid or anhydride thereof (b), the phenolic hydroxyl group-containing ethylenically unsaturated compound as a reaction product, and the di-substituted product of the compound (a), 2. The method for producing a phenolic hydroxyl group-containing ethylenically unsaturated compound according to claim 1, wherein the content of the phenolic hydroxyl group-containing ethylenically unsaturated compound in the reaction solution after the reaction is 50 mol % or more.

8. relative to the total number of moles of the compound (a), the unsaturated monocarboxylic acid or anhydride thereof (b), the phenolic hydroxyl group-containing ethylenically unsaturated compound as a reaction product, and the di-substituted product of the compound (a), 2. The method for producing an ethylenically unsaturated compound containing a phenolic hydroxyl group according to claim 1, wherein the content of the disubstituted compound of the compound (a) in the reaction solution after the reaction is 15 mol % or less.

9. a purification step of washing the reaction solution with water after the completion of the reaction to precipitate a phenolic hydroxyl group-containing ethylenically unsaturated compound, 2. The method for producing a phenolic hydroxyl group-containing ethylenically unsaturated compound according to claim 1, wherein the isolated yield of the phenolic hydroxyl group-containing ethylenically unsaturated compound is 30 mol % or more relative to the theoretical yield when the reaction rate is 100 mol %.

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