Resin composition, resist film using resin composition, pattern forming method using resin composition, method for producing electronic device including pattern forming method, electronic device produced by method for producing electronic device, resin, and method for producing resin

Abstract

To provide a resin composition that allows pattern formation while meeting, at the same time, high sensitivity, high resolution, and reduced line width roughness in an ultrafine region.SOLUTION: A resin composition comprises: a resin (A) including a repeating unit represented by the following formula (1), an acrylate ester monomer unit having an acid-dissociable group, and a monomer unit composed of a styrene derivative having an acid-dissociable group; and a compound (B) which produces an organic acid when irradiated with active energy rays. (R1 to R6 independently denote a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, with R1 and R2, R3 and R4, and R5 and R6 each optionally joining together to form a ring. n denotes an integer of 0 to 2.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition used as a resist or the like in the manufacturing process of a semiconductor device, a resist film using the resin composition, a pattern forming method using the resin composition, and a manufacturing method of an electronic device including the pattern forming method. [Background technology]

[0002] Conventionally, in the manufacturing process of semiconductor devices such as ICs and LSIs, microfabrication has been performed by lithography using photoresist compositions. In recent years, with the increasing integration density of integrated circuits, there has been a demand for ultrafine pattern formation, and lithography using electron beams, X-rays, or EUV light has also been developed. In these electron beam, X-ray, or EUV light lithography processes, resist compositions that have high sensitivity and high resolution and can suppress line width roughness (LWR) are desired.

[0003] As a resist suitable for photolithography processes, chemically amplified positive resist compositions that utilize acid-catalyzed reactions have been investigated from the viewpoint of achieving high sensitivity. Among these, chemically amplified positive resist compositions that contain as their main components a resin that is insoluble or poorly soluble in alkaline developers but has a property that side chains having protecting groups that are dissociated by acid undergo an acid-catalyzed deprotection reaction to become soluble in alkaline developers, and an acid generator have been effectively used.

[0004] However, there is experimental evidence that there is a trade-off between high sensitivity, high resolution, and good line width roughness (the RLS trade-off), and attempts to improve one important property (e.g., sensitivity) by changing the resist composition formulation result in a degradation of one or both of the other properties (e.g., line width roughness and resolution). This effect limits the geometries achievable in high-resolution photolithography, including photolithography using extreme ultraviolet (EUV) and electron beam irradiation sources.

[0005] In order to solve the above problems, photoresists have been studied that use resins with a main chain scission structure in which the bonds in the main chain are cleaved by acid, thereby reducing the molecular weight of the resin in the exposed region and improving the dissolution contrast between the exposed and unexposed regions to form images (Patent Documents 1 to 3 listed below). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-154054 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-37880 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-38604 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the polymer is composed only of a main chain scission structure (Patent Document 1), it is not possible to impart solubilization by deprotecting the side chain, and solubilization is not possible until the molecular weight is completely reduced, resulting in insufficient performance and difficulty in imparting etching resistance, adhesion, and other properties that can generally be imparted by side chain functional groups. Furthermore, when the main chain scission structure uses a structure that is highly sensitive to acids, such as an acetal skeleton (Patent Document 2 and Patent Document 3), the acetal skeleton is very highly reactive, and thus storage stability tends to be poor.

[0008] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using a resin having an acid-decomposable ester structure, which is used as a side-chain decomposition structure, as a main-chain decomposition structure, and by simultaneously progressing main-chain decomposition and side-chain decomposition, solubilization through functional group conversion and promotion of solubilization through main-chain decomposition can be achieved at the same time. Therefore, an object of the present invention is to provide a resin composition that is capable of forming a pattern while simultaneously satisfying high sensitivity, high resolution, and suppression of line width roughness in an ultrafine region, a pattern formation method using the same, and a resist film formed by the method. [Means for solving the problem]

[0009] The present invention has the following aspects [1] to

[14] .

[0010] [1] A resin composition comprising: a resin (A) containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2); and a compound (B) that generates an organic acid upon irradiation with active energy rays:

[0011] [ka] (R1 to R6 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. R1 and R2, R3 and R4, and R5 and R6 may be linked to each other to form a ring. n represents an integer of 0 to 2.)

[0012] [ka] (R7 represents a hydrogen atom or a methyl group, and R8 represents the following formula (3).)

[0013] [ka] (R9 represents a monovalent organic group, R 10 and R 11 each independently represents a monovalent acid-dissociable group, p is an integer of 0 to 3, and q is an integer of 1 to 3.

[0014] [2] The resin composition according to [1], wherein n in formula (1) is 0.

[0015] [3] The resin composition according to [1] or [2], wherein R5 in the formula (1) is a hydrogen atom.

[0016] [4] The resin composition according to any one of [1] to [3], wherein R6 in the formula (1) is an aryl group.

[0017] [5] A resin composition for a resist, wherein the resin composition according to any one of [1] to [4] is used for forming a resist film.

[0018] [6] A resist film formed using the resin composition according to any one of [1] to [4].

[0019] [7] A pattern forming method, comprising forming a film using the resin composition according to any one of [1] to [4], and developing the film by irradiating it with active energy rays.

[0020] [8] A method for manufacturing an electronic device, comprising the pattern formation method according to [7].

[0021] [9] An electronic device manufactured by the method for manufacturing an electronic device according to [8].

[0022]

[10] A resin (A) containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2):

[0023] [ka] (R1 to R6 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. R1 and R2, R3 and R4, and R5 and R6 may be linked to each other to form a ring. n represents an integer of 0 to 2.)

[0024] [ka] (R7 represents a hydrogen atom or a methyl group, and R8 represents the following formula (3).)

[0025] [ka] (R9 represents a monovalent organic group, R 10 and R 11 each independently represents a monovalent acid-dissociable group, p is an integer of 0 to 3, and q is an integer of 1 to 3.

[0026]

[11] The resin according to

[10] , wherein n in formula (1) is 0.

[0027]

[12] The resin (A) according to

[10] or

[11] , wherein R5 in the formula (1) is a hydrogen atom.

[0028]

[13] Resin (A) according to any one of

[10] to

[12] , wherein R6 in formula (1) is an aryl group.

[0029]

[14] . A method for producing the resin according to any one of

[10] to

[13] , comprising a step of polymerizing a mixture containing a monomer having a cyclic ketene acetal structure and at least one selected from a styrene derivative or a (meth)acrylate substituted with an acid-dissociable group. [Effects of the Invention]

[0030] When the resin composition of the present invention is formed into a resist film, it is possible to form a pattern while simultaneously achieving high sensitivity, high resolution, and suppressed line width roughness in ultrafine regions. This is thought to be because the main chain has a structure similar to that of the side chain, which allows the side chain and main chain to be simultaneously acid-decomposed, resulting in simultaneous solubilization due to decomposition of the side chain and main chain. This significantly improves the dissolution contrast between exposed and unexposed areas, and is thought to eliminate the RLS trade-off. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention will be described below based on one embodiment, but the present invention is not limited to this embodiment. In addition, in this specification, there are some places where the expression "~" is used to indicate a numerical range from a lower limit value to an upper limit value of a numerical value, but the numerical range in this description is a numerical range specified as being equal to or greater than the lower limit value and equal to or less than the upper limit value, including the lower limit value itself and the upper limit value itself.

[0032] [Resin composition] A resin composition according to one embodiment of the present invention (hereinafter also referred to as the present resin composition) contains a resin (A) containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), and a compound (B) that generates an organic acid when irradiated with active energy rays.

[0033] [ka]

[0034] In the above formula (1), R1 to R6 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. R1 and R2, R3 and R4, and R5 and R6 may be linked to each other to form a ring. n represents an integer of 0 to 2.

[0035] [ka]

[0036] In the above formula (2), R7 represents a hydrogen atom or a methyl group, and R8 represents the following formula (3).

[0037] [ka]

[0038] In the above formula (3), R represents a monovalent organic group, and R 10 and R 11 each independently represents a monovalent acid-dissociable group, p is an integer of 0 to 3, and q is an integer of 1 to 3.

[0039] <Resin (A)> The resin (A) includes a copolymer containing a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2). In formula (1), R1 to R6 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. R1 and R2, R3 and R4, and R5 and R6 may be linked to each other to form a ring. n is the number of repetitions of the structure represented by -C(R3)(R4)- and represents an integer of 0 to 2. n is preferably 0 or 1, and more preferably 0. When n is 0 or 1, etching resistance is increased when used as a resist, which is preferable.

[0040] The alkyl group in R1 to R6 may be linear or branched, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a pentyl group, a hexyl group, and an ethylhexyl group. The cycloalkyl group in R1 to R6 may be a monocyclic or polycyclic group, or may be a spirocyclic group, and examples thereof include a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and a tetracyclodecanyl group. Examples of the aryl group in R1 to R6 include a phenyl group, a 4-methoxyphenyl group, and a naphthyl group, and may be a heteroaromatic ring.

[0041] R1 and R2, R3 and R4, and R5 and R6 may be bonded to each other to form a ring structure. The ring structure is preferably a cycloalkyl ring structure, and specific examples thereof include the same as those in the cycloalkyl groups represented by R1 to R6 above.

[0042] The alkyl groups, cycloalkyl groups, and aryl groups of R1 to R6 may further have a substituent, examples of which include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an alkyloxycarbonyl group, and a halogen atom. Specifically, the alkyl group, cycloalkyl group, and aryl group of R1 to R6 are each represented by -R A , -OR A , -COR A , -CO2R A , -SR A , -SO2R A , -SO3R A , -SO2N(Rd1)R A Rd1 represents an alkyl group, a cycloalkyl group, or an aryl group. A represents an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. A Specific examples of the alkyl group, cycloalkyl group, and aryl group as R include the same as those given as specific examples of R1 to R6. A Specific examples of the aralkyl group as R1 include structures in which an aryl group listed as a specific example of R1 to R6 is substituted on an alkyl group listed as a specific example of R1 to R6.

[0043] The number of carbon atoms in the alkyl group, cycloalkyl group, and aryl group in R1 to R6 is not particularly limited, but the alkyl group preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkyl group preferably has 3 to 20 carbon atoms, and more preferably 3 to 10 carbon atoms. The aryl group preferably has 6 to 20 carbon atoms, and more preferably 6 to 10 carbon atoms. In R1 to R6, the total number of carbon atoms of R1 to R6 is preferably 0 to 25, and more preferably 0 to 15.

[0044] Preferably, R3, R4, and R5 are each independently a hydrogen atom, and R6 is an aryl group. When R5 is a hydrogen atom and R6 is an aryl group, the introduction rate during polymerization tends to be high, enabling more efficient synthesis, which is preferred. Furthermore, R1 is preferably an alkyl group, a cycloalkyl group, or an aryl group, and R2 is preferably an alkyl group, a cycloalkyl group, or a hydrogen atom.

[0045] Specific examples of formula (1) include structures of formulas (1-1, 1-2, 1-3, 1-4).

[0046] [ka]

[0047] In formula (2), R7 represents a hydrogen atom or a methyl group, and is preferably a methyl group. Furthermore, R8 represents the above formula (3), and in the above formula (3), R9 represents a monovalent organic group, and R 10 and R 11 each independently represents a monovalent acid-dissociable group. Examples of the monovalent organic group for R9 include linear or branched alkyl groups having 1 to 12 carbon atoms, such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, and t-butyl group; and linear or branched alkoxy groups having 1 to 12 carbon atoms, such as a methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, and t-butoxy group, with a methyl group, ethyl group, n-butyl group, and t-butyl group being preferred. R 10 and R 11 The monovalent acid-dissociable group R is a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, a triorganosilyl group, a triorganogermyl group, an alkoxycarbonyl group, an acyl group, or a cyclic acid-dissociable group. 10 and R 11 are mutually independent, and R 10 When there are multiple, they may be the same or different.

[0048] Examples of the substituted methyl group include a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, an ethylthiomethyl group, a methoxyethoxymethyl group, a benzyloxymethyl group, a benzylthiomethyl group, a phenacyl group, a bromophenacyl group, a methoxyphenacyl group, a methylthiophenacyl group, an α-methylphenacyl group, a cyclopropylmethyl group, a benzyl group, a diphenylmethyl group, a triphenylmethyl group, a bromobenzyl group, a nitrobenzyl group, a methoxybenzyl group, a methylthiobenzyl group, an ethoxybenzyl group, an ethylthiobenzyl group, a piperonyl group, a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an i-propoxycarbonylmethyl group, an n-butoxycarbonylmethyl group, a t-butoxycarbonylmethyl group, and an adamantylmethyl group.

[0049] Examples of the 1-substituted ethyl group include a 1-methoxyethyl group, a 1-methylthioethyl group, a 1,1-dimethoxyethyl group, a 1-ethoxyethyl group, a 1-ethylthioethyl group, a 1,1-diethoxyethyl group, a 1-ethoxypropyl group, a 1-propoxyethyl group, a 1-cyclohexyloxyethyl group, a 1-phenoxyethyl group, a 1-phenylthioethyl group, a 1,1-diphenoxyethyl group, a 1-benzyloxyethyl group, a 1-benzylthioethyl group, a 1-cyclopropylethyl group, a 1-phenylethyl group, a 1,1-diphenylethyl group, a 1-methoxycarbonylethyl group, a 1-ethoxycarbonylethyl group, a 1-n-propoxycarbonylethyl group, a 1-isopropoxycarbonylethyl group, a 1-n-butoxycarbonylethyl group, and a 1-t-butoxycarbonylethyl group.

[0050] Examples of the 1-branched alkyl group include an i-propyl group, a sec-butyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 1-methylbutyl group, a 1,1-dimethylbutyl group, etc. Examples of the triorganosilyl group include tricarbylsilyl groups such as a trimethylsilyl group, an ethyldimethylsilyl group, a methyldiethylsilyl group, a triethylsilyl group, an i-propyldimethylsilyl group, a methyldi-i-propylsilyl group, a tri-i-propylsilyl group, a t-butyldimethylsilyl group, a methyldi-t-butylsilyl group, a tri-t-butylsilyl group, a phenyldimethylsilyl group, a methyldiphenylsilyl group, and a triphenylsilyl group.

[0051] Examples of the triorganogermyl group include tricarbylgermyl groups such as a trimethylgermyl group, an ethyldimethylgermyl group, a methyldiethylgermyl group, a triethylgermyl group, an isopropyldimethylgermyl group, a methyldi-i-propylgermyl group, a tri-i-propylgermyl group, a t-butyldimethylgermyl group, a methyldi-t-butylgermyl group, a tri-t-butylgermyl group, a phenyldimethylgermyl group, a methyldiphenylgermyl group, and a triphenylgermyl group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an i-propoxycarbonyl group, and a t-butoxycarbonyl group.

[0052] Examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a heptanoyl group, a hexanoyl group, a valeryl group, a pivaloyl group, an isovaleryl group, a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group, an oxalyl group, a malonyl group, a succinyl group, a glutaryl group, an adipoyl group, a piperoyl group, a suberoyl group, an azelaoyl group, a sebacoyl group, an acryloyl group, a propioloyl group, Examples include methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, campholoyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydratropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group, p-toluenesulfonyl group, and mesyl group.

[0053] Furthermore, examples of the cyclic acid-dissociable group include a cyclopropyl group, a cyclopentyl group, a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a 1-ethylcyclohexyl group, a 4-methoxycyclohexyl group, a cyclohexenyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrothiofuranyl group, a 3-bromotetrahydropyranyl group, a 4-methoxytetrahydropyranyl group, a 4-methoxytetrahydrothiopyranyl group, a 3-tetrahydrothiophene-1,1-dioxide group, a norbornyl group, a methylnorbornyl group, an ethylnorbornyl group, an isobornyl group, a tricyclodecanyl group, a dicyclopentenyl group, an adamantyl group, a 2-methyl-2-adamantyl group, and a 2-ethyl-2-adamantyl group.

[0054] Of these monovalent acid-dissociable groups, a t-butyl group, a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a 1-ethylcyclohexyl group, a benzyl group, a 1-methoxyethyl group, a 1-ethoxyethyl group, a trimethylsilyl group, a t-butoxycarbonyl group, a t-butoxycarbonylmethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrothiofuranyl group, a 2-methyl-2-adamantyl group, and the like are preferred.

[0055] In formula (3), p is an integer of 0 to 3, preferably 0 to 2, and more preferably 0 to 1. Furthermore, q is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

[0056] In resin (A), the ratio of the repeating units of formula (1) to the repeating units of formula (2) is preferably 1:99 to 50:50 (mol%), more preferably 2:98 to 40:60 (mol%), and even more preferably 2.5:97.5 to 30:70 (mol%). When the ratio of the repeating units of formula (1) to the repeating units of formula (2) is within the above range, when used as a resist, solubilization due to decomposition of the side chains and main chain occurs in a balanced manner, resulting in excellent resist performance.

[0057] Resin (A) may have a repeating unit of formula (3) other than the repeating units of formula (1) and formula (2). Examples of the repeating unit (3) other than the repeating units of formula (1) and formula (2) include structures obtained by radical polymerization of a vinyl monomer. The vinyl monomer is not particularly limited, but is preferably a (meth)acrylate compound having a lactone ring skeleton such as a butyrolactone-yl group, a norbornane lactone-yl group, or an oxynorbornane lactone-yl group, or a hydroxystyrene compound. These repeating units may be used alone or in combination of two or more. When a repeating unit (3) other than the repeating units of formula (1) and formula (2) is contained, the content of this component is preferably 70 mol % or less, more preferably 50 mol % or less of the total. The ratio of repeating units was measured using CDCl3 as the measurement solvent. 1 It can be measured by H-NMR.

[0058] There are no particular restrictions on the weight average molecular weight (Mw) of the resin (A) as long as it is soluble in the solvent used to prepare the resist, but it is preferably 1,000 to 200,000, more preferably 3,000 to 150,000, and even more preferably 5,000 to 100,000. The peak molecular weight (Mp) of the resin (A) is preferably from 500 to 200,000, more preferably from 1,500 to 150,000, and even more preferably from 4,000 to 100,000. The weight average molecular weight (Mw) and the peak molecular weight (Mp) can be measured, for example, by gel permeation chromatography (GPC).

[0059] The content of the resin (A) in the composition is preferably 30 to 99.9 mass %, more preferably 50 to 99 mass %, and particularly preferably 70 to 98 mass %, based on the total solid content of the resin composition.

[0060] <Method for producing resin (A)> Resin (A) is not particularly limited, but can be produced by a method in which, for example, at least one selected from the group consisting of a monomer having a cyclic ketene acetal structure that becomes repeating unit (1) after ring-opening polymerization, such as 2-methylene-4-phenyl-1,3-dioxaspiro[4,5]decane (CyPCKA), and a monomer that forms repeating unit (2), such as a styrene derivative or (meth)acrylate substituted with an acid-dissociable group, is subjected to known radical polymerization to obtain a copolymer solution having repeating units (1) and (2), and the obtained copolymer solution is purified by a known reprecipitation method to obtain resin (A) having repeating units (1) and (2).

[0061] When the resin (A) of the present invention is used as a resin for a chemically amplified resist composition, it is preferable to produce it by a preparation method in which the content ratio of each repeating unit is predetermined and the predetermined composition is obtained. Therefore, as a method that can control the composition of the produced copolymer by the charge ratio of the raw material monomer components used, for example, a simple and suitable method is the so-called drop polymerization method, in which a monomer solution in which a monomer and a polymerization initiator are dissolved in an organic solvent is dropped into an organic solvent maintained at a constant temperature.

[0062] The organic solvent used in this dropping polymerization method is not particularly limited as long as it can dissolve at least the monomers and the polymerization initiator. A solvent that can uniformly dissolve not only the monomers but also the final copolymer at the polymerization reaction temperature is preferred, and among these, unsaturated carboxylic acid ester solvents, unsaturated ether solvents, or aromatic hydrocarbon solvents are preferred. Specific examples include propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), 1,4-dioxane, tetrahydrofuran (THF), butyl acetate, ethyl acetate, toluene, xylene, and mesitylene.

[0063] In the dropping polymerization method, the polymerization initiator used is not particularly limited as long as it can initiate radical polymerization of all the monomer components used at a constant reaction temperature. Specific examples include azo compounds such as azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(isobutyrate) dimethyl, and organic peroxides such as benzoyl peroxide. Furthermore, in the polymerization reaction, a chain transfer agent such as n-butanethiol or n-octanethiol may be used to adjust the average molecular weight of the resulting copolymer.

[0064] When using the dropping polymerization method, the polymerization temperature is not particularly limited as long as the average molecular weight of the resulting copolymer can be controlled to the desired level. The polymerization temperature is selected appropriately depending on the type of polymerization initiator used and its addition ratio. For example, when using the above-mentioned azo compounds or organic peroxides, a temperature in the range of 50 to 150°C is generally preferred. Meanwhile, the dropping time is selected appropriately depending on the type of polymerization initiator, its addition ratio, and the polymerization temperature, and is not particularly limited. To achieve a uniform average molecular weight of the resulting copolymer within the desired range, it is preferable to set the polymerization temperature to a relatively low level, and accordingly, the dropping time is typically 4 hours or more, and then maintain that temperature for about 1 hour after the end of the dropping to complete the polymerization.

[0065] The resin (A) solution prepared by the dropping polymerization method is preferably diluted to an appropriate solution viscosity using a good solvent such as tetrahydrofuran or 1,4-dioxane, as necessary, and then the diluted copolymer solution is dropped into a large amount of a poor solvent such as heptane, hexane, methanol, ethanol, or water to precipitate the copolymer. The precipitate is then filtered and purified by a reprecipitation method in which the precipitate is thoroughly dried to remove any remaining solvent.

[0066] <Compound (B)> The compound (B) is a compound that generates an organic acid when irradiated with active energy rays (also referred to as an acid generator). Examples of active energy rays include extreme ultraviolet rays (EUV light), electron beams, KrF excimer lasers, and ArF excimer lasers, and among these, extreme ultraviolet rays (EUV light) with a wavelength of about 13 nm are preferred.

[0067] The acid generator is not particularly limited, and known ones can be used. The organic acid generated is preferably a non-nucleophilic organic acid that has an extremely low ability to undergo nucleophilic reactions.

[0068] Examples of organic acids generated by irradiation with active energy rays include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), sulfonimide acids (sulfonylimide acids, bis(alkylsulfonyl)imide acids, etc.), sulfonmethide acids (tris(alkylsulfonyl)methide acids, etc.), and the like.

[0069] The aliphatic moiety in the aliphatic sulfonic acid and aliphatic carboxylic acid may be an alkyl group or a cycloalkyl group, and preferred examples include linear or branched alkyl groups having 1 to 30 carbon atoms and cycloalkyl groups having 3 to 30 carbon atoms.

[0070] The aromatic group in the aromatic sulfonic acid and aromatic carboxylic acid is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, or a naphthyl group.

[0071] The alkyl group, cycloalkyl group and aryl group mentioned above may have a substituent. Specific examples thereof include a nitro group, a halogen atom such as a fluorine atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms), an acyl group (preferably having 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), an alkylsulfonyl group (preferably having 1 to 15 carbon atoms), an alkyliminosulfonyl group (preferably having 1 to 15 carbon atoms), an aryloxysulfonyl group (preferably having 6 to 20 carbon atoms), an alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), a cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), an alkyloxyalkyloxy group (preferably having 5 to 20 carbon atoms), and a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms). The aryl group and ring structure of each group may further include an alkyl group (preferably having 1 to 15 carbon atoms) as a substituent.

[0072] The aralkyl group in the aralkylcarboxylic acid is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, or a naphthylbutyl group.

[0073] Sulfonylimide acids include, for example, saccharin.

[0074] The alkyl group in the bis(alkylsulfonyl)imide acid and tris(alkylsulfonyl)methide acid is preferably an alkyl group having 1 to 5 carbon atoms. Examples of the substituent on these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, an aryloxysulfonyl group, and a cycloalkylaryloxysulfonyl group, and a fluorine atom or an alkyl group substituted with a fluorine atom is preferred. Furthermore, the alkyl groups in the bis(alkylsulfonyl)imide acid may be bonded to each other to form a ring structure, which increases the acid strength.

[0075] Preferred non-nucleophilic acids include aliphatic sulfonic acids in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, aromatic sulfonic acids substituted with a fluorine atom or a group containing a fluorine atom, bis(alkylsulfonyl)imide acids in which the alkyl group is substituted with a fluorine atom, and tris(alkylsulfonyl)methide acids in which the alkyl group is substituted with a fluorine atom. More preferred non-nucleophilic acids include perfluoroaliphatic sulfonic acids (still more preferably those having 4 to 8 carbon atoms), benzenesulfonic acids containing fluorine atoms, and even more preferred nonafluorobutanesulfonic acid, perfluorooctane sulfonic acid, pentafluorobenzenesulfonic acid, and 3,5-bis(trifluoromethyl)benzenesulfonic acid.

[0076] From the viewpoint of acid strength, it is preferable that the pKa of the generated acid is −1 or less in order to improve sensitivity.

[0077] The organic acid generated from compound (B) is preferably any one of sulfonic acid, sulfonimide acid, and sulfonmethide acid, and more preferably a compound that generates at least any one of sulfonic acid, bis(alkylsulfonyl)imide acid, and tris(alkylsulfonyl)methide acid, which are represented by formulas (2)-1 to (2)-3.

[0078] [ka]

[0079] In the formulae (2)-1 to (2)-3, Rc1 to Rc3 each independently represent an organic group. The organic groups in Rc1 to Rc3 preferably include those having 1 to 30 carbon atoms, and more preferably include alkyl groups or aryl groups which may have a substituent, or groups in which a plurality of these are linked by a linking group such as a single bond, -O-, -CO2-, -S-, -SO3-, or -SON(Rd1)-. Furthermore, they may form a ring structure with other linked alkyl or aryl groups. Rd1 represents an alkyl group, cycloalkyl group, or aryl group, and specific examples thereof include the same as those given as specific examples of R1 to R6 in formula (1) of resin (A).

[0080] Furthermore, as the organic acid generated from the compound (B), an anionic acid represented by the following general formula (AN1) or (AN2) is also preferred.

[0081] [ka]

[0082] In formula (AN1), each Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. In formula (AN1), R 1 , R 2 each independently represents a group selected from a hydrogen atom, a fluorine atom, and an alkyl group, and when a plurality of R 1 , R 2 may be the same or different. L represents a divalent linking group, and when a plurality of L's are present, they may be the same or different. A represents a cyclic organic group. x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

[0083] General formula (AN1) will be explained in more detail. The alkyl group in the alkyl group substituted with at least one fluorine atom of Xf preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. The alkyl group substituted with a fluorine atom of Xf is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Specific examples of Xf include a fluorine atom, CF3, C2F5, C3F7, C4F9, and C5F 11 , C6F 13 , C7F 15 , C8F 17 , CH2CF3, CH2CH2CF3, CH2C2F5, CH2CH2C2F5, CH2C3F7, CH2CH2C3F7, CH2C4F9, CH2CH2C4F9, among which a fluorine atom and CF3 are preferred. It is particularly preferred that both Xf are fluorine atoms.

[0084] R 1 , R 2 The alkyl group in R may have a substituent (preferably a fluorine atom), and preferably has 1 to 4 carbon atoms. More preferably, it is a perfluoroalkyl group having 1 to 4 carbon atoms. 1 , R 2 Specific examples of the alkyl group having the substituent include CF3, C2F5, C3F7, C4F9, and C5F 11 , C6F 13 , C7F 15 , C8F 17 , CH2CF3, CH2CH2CF3, CH2C2F5, CH2CH2C2F5, CH2C3F7, CH2CH2C3F7, CH2C4F9, CH2CH2C4F9, among which CF3 is preferred. R 1 , R 2 is preferably a fluorine atom or CF3.

[0085] y is preferably 0 to 4, more preferably 0. x is preferably 1 to 8, more preferably 1 to 4. z is preferably 0 to 8, more preferably 0 to 4. The divalent linking group for L is not particularly limited, and examples thereof include -COO-, -OCO-, -CO-, -O-, -S-, -SO-, -SO2-, an alkylene group, a cycloalkylene group, an alkenylene group, or a linking group in which a plurality of these are linked together, and linking groups having a total of 12 or less carbon atoms are preferred. Among these, -COO-, -OCO-, -CO-, -O-, and -SO2- are preferred, and -COO-, -OCO-, and -SO2- are more preferred.

[0086] The cyclic organic group for A is not particularly limited, and examples thereof include alicyclic groups, aryl groups, and heterocyclic groups (including not only those having aromatic properties but also those having no aromatic properties).

[0087] The alicyclic group may be monocyclic or polycyclic, and is preferably a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, or a cyclooctyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. Among these, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, are preferred from the viewpoint of suppressing in-film diffusibility in a PEB (post-exposure bake) step and improving MEEF (mask error enhancement factor).

[0088] Examples of the aryl group include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Among these, naphthalene is preferred from the viewpoint of light absorbance at 193 nm, as it has low absorbance.

[0089] Examples of the heterocyclic group include those derived from a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring, and a piperidine ring. Of these, those derived from a furan ring, a thiophene ring, a pyridine ring, and a piperidine ring are preferred.

[0090] The cyclic organic group also includes a lactone structure. The cyclic organic group may have a substituent, and examples of the substituent include an alkyl group (which may be linear or branched and preferably has 1 to 12 carbon atoms), a cycloalkyl group (which may be monocyclic, polycyclic, or spirocyclic and preferably has 3 to 20 carbon atoms), an aryl group (which preferably has 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, a sulfonate ester group, etc. The carbon constituting the cyclic organic group (the carbon contributing to ring formation) may be a carbonyl carbon.

[0091] [ka]

[0092] In formula (AN2), Ar represents an aromatic ring, which may have a further substituent in addition to the sulfonic acid group and the A group. p represents an integer of 0 or greater. A represents a group having a hydrocarbon group. When p is 2 or greater, the multiple A groups may be the same or different.

[0093] General formula (AN2) will be explained in more detail. The aromatic ring represented by Ar is preferably an aromatic ring having 6 to 30 carbon atoms. Specifically, examples thereof include a benzene ring, a naphthalene ring, a pentalene ring, an indene ring, an azulene ring, a heptalene ring, an indecene ring, a perylene ring, a pentacene ring, an acetaphthalene ring, a phenanthrene ring, an anthracene ring, a naphthacene ring, a pentacene ring, a chrysene ring, a triphenylene ring, an indene ring, a fluorene ring, a triphenylene ring, a naphthacene ring, a biphenyl ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, Examples thereof include an indolizine ring, an indole ring, a benzofuran ring, a benzothiophene ring, an isobenzofuran ring, a quinolizine ring, a quinoline ring, a phthalazine ring, a naphthyridine ring, a quinoxaline ring, a quinoxazoline ring, an isoquinoline ring, a carbazole ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a thianthrene ring, a chromene ring, a xanthene ring, a phenoxathiin ring, a phenothiazine ring, and a phenazine ring. A benzene ring, a naphthalene ring, or an anthracene ring is preferred, and a benzene ring is more preferred.

[0094] Examples of substituents that the aromatic ring may have other than the sulfonic acid group and the A group include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.), hydroxyl groups, cyano groups, nitro groups, carboxyl groups, etc. When the aromatic ring has two or more substituents, at least two of the substituents may be bonded to each other to form a ring.

[0095] Examples of groups having a hydrocarbon group include alkoxy groups such as methoxy, ethoxy, and tert-butoxy groups; aryloxy groups such as phenoxy and p-tolyloxy groups; alkylthioxy groups such as methylthioxy, ethylthioxy, and tert-butylthioxy groups; arylthioxy groups such as phenylthioxy and p-tolylthioxy groups; alkoxycarbonyl groups such as methoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl groups; acetoxy groups; straight-chain alkyl groups and branched alkyl groups such as methyl, ethyl, propyl, butyl, heptyl, hexyl, dodecyl, and 2-ethylhexyl groups; alkenyl groups such as vinyl, propenyl, and hexenyl groups; alkynyl groups such as acetylene, propynyl, and hexynyl groups; aryl groups such as phenyl and tolyl groups; and acyl groups such as benzoyl, acetyl, and tolyl groups. The hydrocarbon group in the group having a hydrocarbon group represented by A includes an acyclic hydrocarbon group or a cyclic aliphatic group, and the hydrocarbon group preferably has 3 or more carbon atoms. In the A group, the carbon atom adjacent to Ar is preferably a tertiary or quaternary carbon atom. Examples of the acyclic hydrocarbon group as group A include an isopropyl group, a t-butyl group, a t-pentyl group, a neopentyl group, a s-butyl group, an isobutyl group, an isohexyl group, a 3,3-dimethylpentyl group, and a 2-ethylhexyl group. The upper limit of the number of carbon atoms contained in the acyclic hydrocarbon group is preferably 12 or less, and more preferably 10 or less.

[0096] Examples of the cycloaliphatic group as group A include cycloalkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl, adamantyl, norbornyl, bornyl, camphenyl, decahydronaphthyl, tricyclodecanyl, tetracyclodecanyl, campholoyl, dicyclohexyl, and pinenyl, which may have a substituent. The upper limit of the number of carbon atoms in the cycloaliphatic group is preferably 15 or less, and more preferably 12 or less.

[0097] When the acyclic hydrocarbon group or cyclic aliphatic group has a substituent, examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; alkoxy groups such as methoxy group, ethoxy group, and tert-butoxy group; aryloxy groups such as phenoxy group and p-tolyloxy group; alkylthioxy groups such as methylthioxy group, ethylthioxy group, and tert-butylthioxy group; arylthiooxy groups such as phenylthioxy group and p-tolylthioxy group; methoxycarbonyl group; butoxycarbonyl group; Examples of the alkyl group include alkoxycarbonyl groups such as phenoxycarbonyl groups, acetoxy groups, linear alkyl groups and branched alkyl groups such as methyl groups, ethyl groups, propyl groups, butyl groups, heptyl groups, hexyl groups, dodecyl groups, and 2-ethylhexyl groups, cyclic alkyl groups such as cyclohexyl groups, alkenyl groups such as vinyl groups, propenyl groups, and hexenyl groups, alkynyl groups such as acetylene groups, propynyl groups, and hexynyl groups, aryl groups such as phenyl groups and tolyl groups, hydroxy groups, carboxy groups, sulfonic acid groups, carbonyl groups, and cyano groups. Specific examples of the cycloaliphatic group or acyclic hydrocarbon group represented by A include the following: * represents a bond.

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] From the viewpoint of suppressing acid diffusion, the following structure is more preferred among the above.

[0102] [ka]

[0103] p represents an integer of 0 or more, and the upper limit is not particularly limited as long as it is a chemically feasible number. From the viewpoint of suppressing acid diffusion, p is usually 0 to 5, preferably 1 to 4, more preferably 2 to 3, and most preferably 3.

[0104] From the viewpoint of suppressing acid diffusion, the A group preferably substitutes at least one o-position of the sulfonic acid group, and more preferably has a structure in which it substitutes at two o-positions. In one embodiment, the acid generator (B) of the present invention is a compound that generates an acid represented by the following general formula (BII).

[0105] [ka]

[0106] In the formula, A is the same as A in general formula (AN2), and two As may be the same or different. R1 to R3 each independently represent a hydrogen atom, a group having a hydrocarbon group, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. Specific examples of the group having a hydrocarbon group include the same groups as those exemplified above.

[0107] More preferred examples of the acid generator include compounds represented by the following general formulae (ZI), (ZII) and (ZIII).

[0108] [ka]

[0109] In the above general formula (ZI), R 201 , R 202 and R 203 each independently represents an organic group. R 201 , R 202 and R 203 The organic group as the alkyl group generally has 1 to 30 carbon atoms, and preferably 1 to 20 carbon atoms. Also, R 201 ~R 203Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. 201 ~R 203 Examples of the group formed by combining two of the above include an alkylene group (for example, a butylene group, a pentylene group). Z - represents the anion corresponding to the organic acid.

[0110] R 201 , R 202 and R 203 Examples of the organic group include an aryl group, an alkyl group, and a cycloalkyl group. R 201 , R 202 and R 203 Among these, it is preferable that at least one is an aryl group, and it is more preferable that all three are aryl groups. Examples of the aryl group include phenyl and naphthyl groups, as well as heteroaryl groups such as indole and pyrrole residues. These aryl groups may further have a substituent. Examples of the substituent include a nitro group, a halogen atom such as a fluorine atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms), an acyl group (preferably having 2 to 12 carbon atoms), and an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), but are not limited to these.

[0111] Also, R 201 , R 202 and R 203 Preferred examples of the compounds in which at least one of the groups is not an aryl group include compounds having a phenacylsulfonium salt structure, as represented by the following general formula (ZI-3).

[0112] [ka]

[0113] R 1c ~R 5c each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom. R 6c and R 7c represents a hydrogen atom or an alkyl group. Rx and Ry each independently represent an alkyl group, a 2-oxoalkyl group, an alkoxycarbonylmethyl group, an allyl group, or a vinyl group. R 1c ~R 7c Two or more of these may be bonded to form a ring structure. x and R y may be bonded to form a ring structure. These ring structures may contain oxygen atoms, sulfur atoms, ester bonds, or amide bonds. Z - represents Z in general formula (ZI). - is synonymous with. Specific examples of compound (ZI-3) include the compounds exemplified in paragraphs 0046 and 0047 of JP-A No. 2004-233661 and paragraphs 0040 to 0046 of JP-A No. 2003-35948. Furthermore, R 201 ~R 203 When two of these are bonded to form a ring structure, it is preferable that the ring structure be a structure represented by the following general formula (A1).

[0114] [ka]

[0115] In general formula (A1), R 1a ~R 13a each independently represents a hydrogen atom, a halogen atom or a substituent. R 1a ~R 13a Among these, it is preferable that 1 to 3 are not hydrogen atoms, and R 9a ~R 13a It is more preferable that any one of the above is not a hydrogen atom. Za is a single bond or a divalent linking group. X - represents Z in general formula (ZI). - is synonymous with.

[0116] R 1a ~R 13a is not a hydrogen atom, specific examples thereof include a halogen atom, a linear, branched, or cyclic alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a nitro group, a carboxyl group, an alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an ammonio group, an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl and arylsulfonyla group, Examples of the substituent include an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl and arylsulfinyl group, an alkyl and arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl and heterocyclic azo group, an imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a phosphono group, a silyl group, a hydrazino group, a ureido group, a boronic acid group (-B(OH)), a phosphato group (-OPO(OH)), a sulfato group (-OSOH), and other known substituents. R 1a ~R 13a When is not a hydrogen atom, it is preferably a linear, branched or cyclic alkyl group substituted with a hydroxyl group.

[0117] The divalent linking group of Za includes an alkylene group, an arylene group, a carbonyl group, a sulfonyl group, a carbonyloxy group, a carbonylamino group, a sulfonylamido group, -O-, -S-, an amino group, a disulfide group, -(CH2) n -CO-, -(CH2) n Examples thereof include -SO2-, -CH=CH-, an aminocarbonylamino group, and an aminosulfonylamino group (n is an integer of 1 to 3).

[0118] In addition, R 201 , R 202 and R 203 Among these, preferred structures when at least one is not an aryl group include cationic structures such as those exemplified as compounds represented by formulae (I-1) to (I-70) in paragraphs

[0047] and

[0048] of JP-A No. 2004-233661, and paragraphs

[0040] to

[0046] of JP-A No. 2003-35948, and compounds represented by formulae (I-1) to (I-70) in U.S. Patent Application Publication No. 2003 / 0224288A1, and compounds represented by formulae (IA-1) to (IA-54) and (IB-1) to (IB-24) in U.S. Patent Application Publication No. 2003 / 0077540A1.

[0119] In general formulas (ZII) and (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group, or a cycloalkyl group.

[0120] R 204 ~R 207 The aryl group, alkyl group and cycloalkyl group in the above-mentioned compound (ZI) are 201 ~R 203 The same applies to the aryl group, alkyl group, and cycloalkyl group in the above. R 204 ~R 207 The aryl group, alkyl group, and cycloalkyl group may have a substituent. The substituent may also be the same as R in the above-mentioned compound (ZI). 201 ~R 203 The aryl group, alkyl group, and cycloalkyl group may have any of the above groups.

[0121] Z - represents a non-nucleophilic anion, and Z in general formula (ZI) - Examples of non-nucleophilic anions include those similar to those listed above.

[0122] Further examples of the acid generator include compounds represented by the following general formulae (ZIV), (ZV) and (ZVI).

[0123] [ka]

[0124] In the general formulae (ZIV) to (ZVI), Ar3 and Ar4 each independently represent an aryl group. R 208 , R 209 and R 210 each independently represents an alkyl group, a cycloalkyl group, or an aryl group. A represents an alkylene group, an alkenylene group, or an arylene group.

[0125] Ar3, Ar4, R 208 , R 209 and R 210 Specific examples of the aryl group include R 201 , R 202 and R 203 Specific examples of the aryl group as mentioned above include the same as those mentioned above. R 208 , R 209 and R 210 Specific examples of the alkyl group and cycloalkyl group include R 201 , R 202 and R 203 Specific examples of the alkyl group and cycloalkyl group are the same as those mentioned above. Examples of the alkylene group for A include alkylene groups having 1 to 12 carbon atoms (e.g., methylene, ethylene, propylene, isopropylene, butylene, and isobutylene groups). Examples of the alkenylene group for A include alkenylene groups having 2 to 12 carbon atoms (e.g., ethynylene, propenylene, and butenylene groups). Examples of the arylene group for A include arylene groups having 6 to 10 carbon atoms (e.g., phenylene, tolylene, and naphthylene groups).

[0126] Among the acid generators, particularly preferred examples include the following: Among them, triphenylsulfonium trifluoromethanesulfonate (TPS-Tf) is preferred.

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] The acid generators can be used alone or in combination of two or more. The content of compound (B) in the composition is preferably 0.1 to 20 mass %, more preferably 0.5 to 15 mass %, and even more preferably 1 to 10 mass %, based on the total solid content of the resin composition.

[0133] <Solvent> The solvent that can be used in preparing the resin composition is not particularly limited as long as it dissolves each component. Examples include alkylene glycol monoalkyl ether carboxylates (such as propylene glycol monomethyl ether acetate (PGMEA; also known as 1-methoxy-2-acetoxypropane)), alkylene glycol monoalkyl ethers (such as propylene glycol monomethyl ether (PGME; 1-methoxy-2-propanol)), alkyl lactate esters (such as ethyl lactate and methyl lactate), cyclic lactones (such as γ-butyrolactone, preferably having 4 to 10 carbon atoms), linear or cyclic ketones (such as 2-heptanone and cyclohexanone, preferably having 4 to 10 carbon atoms), alkylene carbonates (such as ethylene carbonate and propylene carbonate), alkyl carboxylates (preferably alkyl acetates such as butyl acetate), and alkyl alkoxyacetates (ethyl ethoxypropionate). Of the above, alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, and cyclic lactones are preferred.

[0134] <Other ingredients (C)> The resin composition may contain, as other component (C), a basic compound, a hydrophobic resin having a structure different from that of resin (A), a carboxylic acid, a carboxylic acid onium salt, a surfactant, a dissolution-inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, an antioxidant, or the like. The basic compound is particularly suitable for use as a quencher to improve performance. The basic compound is preferably an organic basic compound, and more preferably a nitrogen-containing basic compound. The nitrogen-containing basic compound that can be used is not particularly limited, and examples thereof include triethylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-octylamine, tri-n-decylamine, triisodecylamine, dicyclohexylmethylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, didecylamine, methyloctadecylamine, dimethylundecylamine, N,N-dimethyldodecylamine, methyldioctadecylamine, N,N-dibutylaniline, N,N-dihexylaniline, 2,6-diisopropylaniline, and 2,4,6-tri(t-butyl)aniline. When other component (C) is contained in the present resin composition, the content of each other component (C) is preferably 0.01 to 10 mass%, more preferably 0.01 to 5 mass%, and even more preferably 0.01 to 3 mass%, based on the total solid content of the present resin composition.

[0135] <Method of manufacturing the present resin composition> The present resin composition can be obtained, for example, by mixing the resin (A) and the compound (B) as solid components, and, if necessary, other components (C), in a solvent. The mixing ratio in this case is preferably 1 to 15 parts by mass, more preferably 2 to 10 parts by mass of solids relative to 100 parts by mass of solvent.

[0136] <Application> The present resin composition can be suitably used as a resist film in the manufacturing process of electronic devices, such as the production of semiconductor microcircuits, including the production of VLSIs and high-capacity microchips, and is particularly preferably used as a resist composition for producing a resist film.

[0137] When preparing a resist composition, it is preferable to filter the solution using a filter or the like. The filter is preferably a membrane filter made of, for example, polytetrafluoroethylene (PTFE), and although not particularly limited, the pore size is preferably 0.1 μm to 2.5 μm, more preferably 0.1 μm to 1.0 μm, and even more preferably 0.1 μm to 0.5 μm.

[0138] <Pattern formation method> When the present resin composition is used as a resist composition, a film is formed using the present resin composition, and the film is irradiated with active energy rays and developed to form a pattern.

[0139] The film can be formed by applying the resin composition to a substrate (e.g., silicon, silicon dioxide coated) such as that used in the manufacture of integrated circuit elements by a suitable application method such as spin coating, and then drying at 80 to 120°C. In this case, if necessary, a commercially available inorganic or organic anti-reflective coating can be used, and further, an anti-reflective coating can be applied to the lower layer of the resist.

[0140] Examples of the active energy rays to be irradiated include extreme ultraviolet rays (EUV light), electron beams, KrF excimer lasers, and ArF excimer lasers, and among these, extreme ultraviolet rays (EUV light) with a wavelength of about 13 nm are preferred.

[0141] After the above irradiation, it is preferable to bake (heat) the film before developing. When baking (heating) is performed, the heating temperature is preferably 50 to 150°C, more preferably 60 to 150°C, and even more preferably 80 to 140°C. When baking (heating) is performed, the heating time is preferably 30 to 3600 seconds, more preferably 30 to 1800 seconds, and even more preferably 30 to 600 seconds. Baking can be performed by means provided in a normal exposure / developing machine, and may also be performed using a hot plate or the like.

[0142] After the exposure, development is carried out using an alkaline developer to selectively remove the exposed areas of the photosensitive layer.

[0143] Examples of the alkaline developer include alkaline aqueous solutions containing alkaline compounds such as alkali metal hydroxides, aqueous ammonia, mono-, di-, or tri-alkylamines, mono-, di-, or tri-alkanolamines, heterocyclic amines, tetraalkylammonium hydroxides, choline, 1,8-diazabicyclo[5.4.0]-7-undecene, and 1,5-diazabicyclo[4.3.0]-5-nonene, typically dissolved to a concentration of 1 to 10% by weight, preferably 1 to 5% by weight, and particularly preferably 1 to 3% by weight. A 2.38% by weight aqueous solution of tetramethylammonium hydroxide is particularly desirable. The alkaline aqueous developer may also contain water-soluble organic solvents such as methanol and ethanol, or surfactants, as appropriate. When forming a resist pattern, a protective film may be provided on the resist film to protect it from the effects of basic impurities present in the ambient atmosphere.

[0144] Examples of development methods that can be applied include a method in which the substrate is immersed in a tank filled with developer for a certain period of time (dip method), a method in which developer is piled up on the surface of the substrate by surface tension and left to stand for a certain period of time (puddle method), a method in which developer is sprayed onto the surface of the substrate (spray method), and a method in which developer is continuously dispensed by scanning a developer dispensing nozzle at a constant speed over a substrate that is rotating at a constant speed (dynamic dispense method). After the development step, a step of stopping the development while replacing the solvent with another solvent may be carried out. The development time is preferably a time required for the present resin composition and the like in the unexposed or exposed areas of the photosensitive layer to be sufficiently dissolved, and is usually preferably 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the developer is preferably from 0 to 50°C, more preferably from 15 to 35°C. The amount of developer can be adjusted appropriately depending on the development method.

[0145] The pattern forming method of the present invention may include a rinsing step after the development step.

[0146] As the rinse solution in the rinse treatment carried out after the alkaline development, pure water may be used with an appropriate amount of surfactant added. The surfactant may be the same as those used in the photosensitive composition described above, and the amount used is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse solution.

[0147] In the rinsing step, the developed pattern-formed substrate is washed with the above-mentioned rinse solution. The cleaning method is not particularly limited, but may be, for example, a method in which a rinse solution is continuously applied to a substrate rotating at a constant speed (spin coating method), a method in which a substrate is immersed in a tank filled with rinse solution for a certain period of time (dip method), or a method in which a rinse solution is sprayed onto the substrate surface (spray method). Of these, it is preferable to perform the cleaning process using the spin coating method, and then rotate the substrate at a rotation speed of 2000 to 4000 rpm after cleaning to remove the rinse solution from the substrate. The rotation time of the substrate can be set depending on the rotation speed within a range that achieves removal of the rinse solution from the substrate, but is usually 10 seconds to 3 minutes. Rinsing is preferably performed at room temperature. The rinsing time is preferably set so that no alkaline developer remains on the substrate, and is usually preferably 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the rinse liquid is preferably 0 to 50°C, more preferably 15 to 35°C. The amount of the rinse solution can be adjusted appropriately depending on the rinse method.

[0148] After the development treatment or the rinsing treatment, a treatment can be carried out in which the developer or the rinsing liquid adhering to the pattern is removed using a supercritical fluid. Furthermore, after the development treatment, rinsing treatment, or treatment with a supercritical fluid, a heat treatment can be carried out to remove the solvent remaining in the pattern. The heating temperature and time are not particularly limited as long as a good resist pattern can be obtained, but are usually 40 to 160°C and 10 seconds to 3 minutes. The heat treatment may be carried out multiple times.

[0149] <Physical properties of the present resin composition> (Peak molecular weight (Mp)) When the present resin composition is used to form a resist film, the peak molecular weight (Mp) of the exposed area after post-exposure baking is preferably from 100 to 100,000, more preferably from 200 to 50,000, and even more preferably from 300 to 10,000. The peak molecular weight (Mp) of the exposed area after post-exposure baking can be measured, for example, by gel permeation chromatography (GPC).

[0150] (Reduction rate of peak molecular weight (Mp) after post-exposure bake treatment) When the present resin composition is used to form a resist film, the reduction rate of the peak molecular weight (Mp) after post-exposure baking in the exposed area is preferably 30% to 95%, more preferably 30% to 80%, and even more preferably 30% to 70%. The reduction rate of the peak molecular weight (Mp) is, for example, (1 - peak molecular weight after post-exposure baking treatment of the exposed area of ​​the resin composition / peak molecular weight of resin (A)) x 100 (%) It can be calculated as follows. [Example]

[0151] Examples of the present invention will be described below. However, the present invention is not limited to these examples. In the following description, "parts" means "parts by mass."

[0152] The following raw materials were used in preparing the Examples and Comparative Examples. The abbreviations and trade names of each raw material are shown below.

[0153] <Raw materials> (1) ECHMA: 1-ethylcyclohexyl methacrylate (Osaka Organic Chemical Industry Co., Ltd.) (2) NLMA: 3,5-norbornane lactone-2-yl methacrylate (Osaka Organic Chemical Industry Co., Ltd.) (3) CyPCKA: 2-methylene-4-phenyl-1,3-dioxaspiro[4,5]decane (compound prepared in Preparation Example 1 below) (4) PGMEA: propylene glycol-1-monomethyl ether-2-acetate (Tokyo Chemical Industry Co., Ltd.) (5) GBL: γ-butyrolactone (Tokyo Chemical Industry Co., Ltd.) (6) V-601 (trade name): 2,2'-azobis(isobutyrate) dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (7) Omnirad 184 (trade name): 1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins BV) (8) TPS-Tf: Triphenylsulfonium trifluoromethanesulfonate (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0154] [Production Example 1: Synthesis of CyPCKA] Omnirad 184 (16.3 g, 79.9 mmol), butanol (3.55 g, 47.9 mmol), sodium hydroxide (3.20 g, 79.9 mmol), and dimethoxyethane (60.0 mL) were placed in a 500 mL flask and heated with stirring at 80° C. for 6 hours. Next, the mixture was diluted with diethyl ether (60.0 mL) and ion-exchanged water (60.0 mL), and the organic layer was recovered by separation. The solvent in the recovered organic layer was evaporated, and then recrystallized with diethyl ether to obtain 14.2 g of 1-[hydroxy(phenyl)methyl]cyclohexanol as a white solid. 1-[hydroxy(phenyl)methyl]cyclohexanol (10.0 g, 48.4 mmol), bromoacetaldehyde dimethyl acetal (8.19 g, 48.4 mmol), toluenesulfonic acid monohydrate (0.46 g, 2.42 mmol), and toluene (97.0 mL) were placed in a 300 mL flask and heated with stirring at 85°C for 4 hours. After the insoluble matter in the reaction solution was removed by filtration, the solvent was evaporated. Tetrahydrofuran (42.8 mL) and trioctylmethylammonium chloride (0.34 g, 0.86 mmol) were added, and the mixture was cooled to 0° C., after which potassium t-butoxide (9.61 g, 85.6 mmol) was added, and the mixture was stirred for 1 hour while slowly warming to room temperature. Then, after insoluble matters in the reaction solution were removed by filtration, the solvent was distilled off and distillation under reduced pressure was carried out to obtain 4.2 g of CyPCKA as a pale yellow liquid.

[0155] [Production Example 2: Synthesis of Resin A-1] A polymerization reactor equipped with a stirrer, condenser, and thermometer was charged with 46.3 parts of toluene, 1.80 parts of ECHMA, 0.02 parts of NLMA, and 6.8 parts of CyPCKA, and the temperature inside the polymerization reactor was raised to 80°C while stirring. Next, a solution containing 22.3 parts of ECHMA, 3.00 parts of NLMA, 26.5 parts of toluene, and 0.62 parts of V-601 was added dropwise at a constant rate over 6 hours to the polymerization reactor maintained at 80°C. The mixture was then maintained at 80°C for 1 hour while stirring. After cooling to below 40°C, the resulting reaction solution was added dropwise to 559 parts of methanol while stirring, yielding a white precipitate. The precipitate was filtered, redispersed in 525 parts of ethanol, washed, and then filtered and dried under reduced pressure at 60°C for approximately 24 hours.

[0156] [Production Example 3: Synthesis of Resin X-1] A polymerization reactor equipped with a stirrer, condenser, and thermometer was charged with 21.1 parts of PGMEA, 14.1 parts of GBL, 1.75 parts of ECHMA, and 0.41 parts of NLMA. The temperature inside the polymerization reactor was raised to 80°C while stirring. Next, a solution containing 17.9 parts of ECHMA, 6.70 parts of NLMA, 6.10 parts of PGMEA, 31.0 parts of GBL, and 0.95 parts of V-601 was added dropwise at a constant rate over 6 hours to the polymerization reactor maintained at 80°C. The mixture was then maintained at 80°C for 1 hour while stirring. After cooling to below 40°C, the resulting reaction solution was added dropwise to a mixed solution of 363 parts of methanol and 196 parts of water while stirring, resulting in the precipitation of a white precipitate. The precipitate was filtered, redispersed in a mixed solution of 492 parts of methanol and 33 parts of water, washed, and then filtered and dried under reduced pressure at 60°C for approximately 24 hours.

[0157] [Measurement method] The weight average molecular weight (Mw), peak molecular weight (Mp), and ratio of repeating units (1) and (2) were measured as follows, and the results are shown in Table 1 below.

[0158] <Weight average molecular weight (Mw) and peak molecular weight (Mp)> Mw and Mp were measured using gel permeation chromatography (GPC). 10 mg of the sample to be measured was dissolved in 10 mL of tetrahydrofuran, and the solution was filtered through a 0.45 μm filter to prepare a sample for GPC measurement. A polymer measurement guard column (manufactured by Tosoh Corporation, product name: TSK-GUARD COLUMN SUPER HH) and two polymer measurement columns (manufactured by Tosoh Corporation, product name: TSK-GEL SUPER HM-H) were connected in series to a GPC measurement device (manufactured by Tosoh Corporation, model name: HLC-8320). A differential refractometer (RI) was used as the detector. Measurements were performed under the following conditions: separation column temperature: 40°C, mobile phase: tetrahydrofuran, mobile phase flow rate: 0.6 mL / min, and sample injection volume: 10 μL. A calibration curve was created using several types of polymethyl methacrylate with known molecular weights (Polymer Laboratories, peak molecular weight (Mp) 1,560 to 19,500,000) as standard polymers, and the Mw and Mp values ​​calculated in terms of polymethyl methacrylate were determined.

[0159] <Ratio of repeating units (1), (2) and (3)> The ratio (%) of repeating units (1), (2), and (3) was measured using a nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd., ECZ400S, 400 MHz) and CDCl3 as the measurement solvent. 1 The value was determined from the integral of the peak derived from each repeating unit by H-NMR measurement.

[0160] [Table 1]

[0161] <Preparation of Examples 1 and 2 and Comparative Examples 1 and 2> The components were mixed in the ratios shown in Table 2 below, and then filtered through a membrane filter with a pore size of 0.2 μm to obtain a resin composition. Next, the resin composition was applied using a spin coater onto a 6-inch Si wafer that had been previously treated with hexamethyldisilazane (HMDS), and dried on a hot plate at 100°C for 60 seconds to obtain a resist film with a thickness of 200 nm. The wafer coated with the resist film was exposed under the conditions shown in Table 2 using an analytical exposure system MODEL UVES-2000 (manufactured by Litho Tech Japan). After post-exposure baking was carried out on a hot plate under the conditions shown in Table 2, the exposed portions of the resist film were dissolved in tetrahydrofuran. Then, 3 parts of trimethylsilyldiazomethane (about 10% hexane solution) and 3 parts of methanol were added to 1 part by mass of the resist film, and the mixture was allowed to stand at room temperature for 2 hours to carry out a methyl protection reaction.

[0162] <Evaluation of Peak Molecular Weight (Mp) Reduction Rate> For each example and comparative example, the peak molecular weight (Mp) after exposure was determined by the GPC measurement described above, and the reduction rate was calculated. The results are shown in Table 2 below. The reduction rate was calculated by (1 - peak molecular weight after reduction / peak molecular weight before reduction) x 100 (%).

[0163] [Table 2]

[0164] <Result> Examples 1 and 2, which used a resin (A-1) containing the structure of repeating unit (1) and repeating unit (2) in the resin composition, showed a larger reduction in peak molecular weight (Mp) than Comparative Examples 1 and 2, which used a resin (X-1) not containing the structure of repeating unit (1) in the resin composition. This suggests that when this resin composition is used as a resist film, high sensitivity and high resolution can be achieved in the ultrafine resist region, and line width roughness can be suppressed.

Claims

1. A resin composition comprising: a resin (A) containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2); and a compound (B) that generates an organic acid when irradiated with active energy rays: 【Chemical 1】 (R １ ~R ６ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. １ and R ２ , R ３ and R ４ , R ５ and R ６ may be linked to each other to form a ring, and n represents an integer of 0 to 2. 【Chemistry 2】 (R ７ represents a hydrogen atom or a methyl group, R ８ represents the following formula (3): 【Chemistry 3】 (R ９ represents a monovalent organic group, R １０ and R １１ each independently represents a monovalent acid-dissociable group, p is an integer of 0 to 3, and q is an integer of 1 to 3.

2. The resin composition according to claim 1, wherein n in formula (1) is 0.

3. R in the formula (1) ５ The resin composition according to claim 1 , wherein is a hydrogen atom.

4. R in the formula (1) ６ The resin composition according to claim 1 , wherein is an aryl group.

5. 5. A resist resin composition, wherein the resin composition according to claim 1 is used for forming a resist film.

6. A resist film formed using the resin composition according to any one of claims 1 to 4.

7. A pattern forming method, comprising forming a film using the resin composition according to any one of claims 1 to 4, and developing the film by irradiating it with active energy rays.

8. A method for manufacturing an electronic device, comprising the pattern forming method according to claim 7 .

9. An electronic device manufactured by the method for manufacturing an electronic device according to claim 8.

10. A resin (A) containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2): 【Chemistry 4】 (R １ ~R ６ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. １ and R ２ , R ３ and R ４ , R ５ and R ６ may be linked to each other to form a ring, and n represents an integer of 0 to 2. 【Chemistry 5】 (R ７ represents a hydrogen atom or a methyl group, R ８ represents the following formula (3): 【Chemistry 6】 (R ９ represents a monovalent organic group, R １０ and R １１ each independently represents a monovalent acid-dissociable group, p is an integer of 0 to 3, and q is an integer of 1 to 3.

11. The resin (A) according to claim 10, wherein n in formula (1) is 0.

12. R in the formula (1) ５ The resin (A) according to claim 10, wherein is a hydrogen atom.

13. R in the formula (1) ６ The resin (A) according to claim 10, wherein is an aryl group.

14. 14. A method for producing the resin according to claim 10, comprising a step of polymerizing a mixture containing a monomer having a cyclic ketene acetal structure and at least one selected from a styrene derivative or a (meth)acrylate substituted with an acid-dissociable group.

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