Resist composition and method for forming a resist pattern

Abstract

To provide a resist composition capable of forming a thick film resist pattern which hardly causes cracks and exhibits good coverage on a substrate while maintaining lithographic characteristics such as resolution and DOF, and to provide a resist pattern forming method using the resist composition.SOLUTION: The resist composition contains a polymer compound (A1) having a constituent unit (a10) represented by general formula (a10-1), an onium salt-based acid generator (B1), a crosslinking agent (C), and a polynuclear phenol low-molecular compound (Z) having five or less phenyl groups and has a solid content concentration of 15 mass% or more. In the formula, R represents a hydrogen atom, a C1-5 alkyl group or a C1-5 halogenated alkyl group; Yax1 represents a single bond or a divalent linking group; and Wax1 represents an optionally substituted aromatic hydrocarbon group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resist composition and a resist pattern forming method. [Background technology]

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display elements. Generally, miniaturization is achieved by shortening the wavelength (increasing the energy) of the exposure light source.

[0003] Resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources and resolution that can reproduce patterns of fine dimensions. Conventionally, chemically amplified resist compositions have been used as resist materials that satisfy these requirements. These compositions contain a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component that generates acid upon exposure.

[0004] In the manufacturing of semiconductor packages, MEMS, etc., there is a process of forming a thick resist film on the surface of the workpiece to create a resist pattern and then performing etching. When a chemically amplified resist composition is used in this process, as the thickness of the resist film increases, it becomes difficult to maintain sensitivity during exposure, the resolution for development decreases, and it becomes difficult to obtain the desired resist pattern shape. In addition, as the thickness of the resist film increases, cracks are more likely to occur in the resist pattern.

[0005] Patent Document 1 proposes a resist composition containing a base component and a specific amount of polyether compound, with a solid content concentration of 25% by mass or more. This resist composition allows for the formation of a thick resist film, and enables the formation of a resist pattern that is less prone to cracking and has good resolution. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-033158 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] For thick-film applications, resists are required not only to reduce crack formation in thick-film patterns, but also to provide coverage on substrates with steps or other uneven surfaces. Furthermore, for thick-film resists, there was room for improvement in lithography characteristics such as resolution and depth of field (DOF). "DOF" refers to the depth of field range in which, when exposure is performed with the same exposure dose but by shifting the focus vertically, a resist pattern can be formed with dimensions such that the deviation from the target dimensions is within a predetermined range. In other words, it is the range in which a resist pattern faithful to the mask pattern can be obtained, and a larger DOF value is preferable.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can form a thick film resist pattern that is less prone to cracking and has good coverage on a substrate, while maintaining lithography characteristics such as resolution and DOF, and a method for forming a resist pattern using the resist composition. [Means for solving the problem]

[0009] To solve the above problems, the present invention employs the following configuration. In other words, a first aspect of the present invention is a resist composition having a solid content of 15% by mass or more, comprising a polymer compound (A1) having a constituent unit (a10) represented by the following general formula (a10-1), an onium salt-based acid generator (B1), at least one crosslinking agent (C) selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluryl-based crosslinking agents, and epoxy-based crosslinking agents, and a polynuclear phenol low molecular weight compound (Z) having five or fewer phenyl groups.

[0010] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. x1 Wa is a single bond or a divalent linking group. x1 n is an aromatic hydrocarbon group which may have substituents. ax1 [ is an integer greater than or equal to 1.]

[0011] A second aspect of the present invention is a resist pattern forming method comprising the steps of forming a resist film on a support using a resist composition according to the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern. [Effects of the Invention]

[0012] According to the present invention, a resist composition is available that can form a thick film resist pattern that is less prone to cracking and has good coverage on a substrate, while maintaining lithography characteristics such as resolution and depth of field (DOF), and a method for forming a resist pattern using the resist composition is also available. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view of a substrate with a stepped surface and a simulated resist pattern formed on its surface. [Figure 2] This is a schematic cross-sectional view of a substrate with a stepped surface and a simulated resist pattern formed on its surface. [Modes for carrying out the invention]

[0014] In this specification and in the claims, "aliphatic" is defined as a concept relative to aromatic, meaning a group, compound, etc., that does not possess aromaticity. Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups within alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups. Examples of "halogen atoms" include fluorine, chlorine, bromine, and iodine atoms. "Constituent unit" refers to the monomer unit (monomer unit) that makes up a polymer compound (resin, polymer, copolymer). When it is stated that a group "may have substituents," this includes both cases where a hydrogen atom (-H) is substituted with a monovalent group and cases where a methylene group (-CH2-) is substituted with a divalent group. "Exposure" is a concept that includes all forms of radiation exposure.

[0015] An "acid-degradable group" is a group that has acid-degradability, meaning that at least some of the bonds in its structure can be cleaved by the action of an acid. Examples of acid-degradable groups whose polarity increases upon the action of an acid include groups that decompose upon the action of an acid to produce polar groups. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO3H). More specifically, examples of acid-degradable groups include groups in which the aforementioned polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0016] The term "acid-dissociable group" refers to both (i) a group that has acid-dissociability, in which the bond between the acid-dissociable group and an adjacent atom can be cleaved by the action of an acid, and (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, further causing the bond between the acid-dissociable group and an adjacent atom to be cleaved. The acid-dissociable group constituting the acid-degradable group must be less polar than the polar group generated by its dissociation. This means that when the acid-dissociable group dissociates due to the action of acid, a polar group with higher polarity is generated, increasing the polarity. As a result, the overall polarity of component (A1) increases. This increase in polarity relatively changes the solubility in the developer; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0017] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly classified into nonpolymers and polymers. Nonpolymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, "low molecular weight compound" refers to a nonpolymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, "resin," "high molecular weight compound," or "polymer" refers to a polymer with a molecular weight of 1000 or more. The molecular weight of polymers shall be the weight-average molecular weight on a polystyrene basis calculated by GPC (gel permeation chromatography).

[0018] "Induced structural units" refer to structural units formed by the cleavage of multiple bonds between carbon atoms, such as ethylenic double bonds. "Acrylic acid ester" may have a substituent that replaces the hydrogen atom bonded to the α-carbon atom. αx ) is an atom or group other than a hydrogen atom. Also, substituents (R αx Itaconic acid diesters in which the substituent (R) is substituted with substituents containing an ester bond, or substituents (R αx This also includes α-hydroxyacrylic esters in which the α group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group thereof. Unless otherwise specified, the α-carbon atom of the acrylic acid ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereafter, acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom is replaced by a substituent are sometimes called α-substituted acrylic acid esters.

[0019] The term "derivative" refers to a compound in which the α-position hydrogen atom of the target compound is substituted with another substituent such as an alkyl group or alkyl halide, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound (which may have the α-position hydrogen atom substituted with a substituent) is substituted with an organic group; and those in which a substituent other than a hydroxyl group is bonded to the target compound (which may have the α-position hydrogen atom substituted with a substituent). Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. As substituents that substitute the hydrogen atom at the α-position of hydroxystyrene, R αx Similar examples include the above.

[0020] In this specification and in the claims, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantioisomers or diastereomers may exist. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture.

[0021] (Resist composition) A resist composition according to a first aspect of the present invention contains a polymer compound (A1) having a constituent unit (a10) represented by general formula (a10-1) (hereinafter also referred to as "component (A1)"), an onium salt-based acid generator (B1) (hereinafter also referred to as "component (B1)"), at least one crosslinking agent (C) selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluryl-based crosslinking agents, and epoxy-based crosslinking agents (hereinafter also referred to as "component (C)"), and a polynuclear phenol low molecular weight compound (Z) having five or fewer phenyl groups (hereinafter also referred to as "component (Z)"). The solid content concentration of the resist composition of this embodiment is 15% by mass or more. When a resist film is formed using such a resist composition, a thick resist film (for example, with a film thickness of 2 μm to 20 μm) can be formed.

[0022] When a resist film is formed using such a resist composition and selective exposure is performed on the resist film, acid is generated in the exposed areas of the resist film. The solubility of component (A) in the developer changes due to the action of this acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0023] <(A) component> Component (A) is a base component whose solubility in the developer changes due to the action of acid. In this invention, the "substrate component" is an organic compound having film-forming ability, preferably an organic compound with a molecular weight of 500 or more. Having a molecular weight of 500 or more improves the film-forming ability and, in addition, facilitates the formation of nanoscale resist patterns. Organic compounds used as base components are broadly classified into nonpolymers and polymers. Nonpolymers typically used have a molecular weight of 500 or more but less than 4000. Hereafter, "low molecular weight compound" refers to a nonpolymer with a molecular weight of 500 or more but less than 4000. Polymers typically used have a molecular weight of 1000 or more. Hereafter, when "resin," "polymer compound," or "polymer" is used, it refers to polymers with a molecular weight of 1000 or more. The molecular weight of the polymer shall be the weight-average molecular weight on a polystyrene basis, calculated by GPC (gel permeation chromatography).

[0024] In the resist composition of this embodiment, component (A) includes at least a polymer compound (A1) having a constituent unit (a10) represented by general formula (a0-1), and further, polymer compounds other than component (A1) and / or low molecular weight compounds may be used in combination. When a resist film is formed using a resist composition containing at least component (A1), and the resist film is selectively exposed, acid is generated from component (B1) in the exposed areas of the resist film. Due to the action of this acid, crosslinking occurs between components (A1) via crosslinkable structural units (a10), and as a result, the solubility of the exposed areas of the resist film in alkaline developer decreases. Therefore, when a resist film obtained by coating a support with the resist composition of this embodiment is selectively exposed during the formation of a resist pattern, the exposed areas of the resist film become poorly soluble in alkaline developer, while the unexposed areas of the resist film remain soluble in alkaline developer. Thus, a negative-type resist pattern is formed by developing with alkaline developer.

[0025] (A1) About the ingredients Component (A1) is a polymer compound having a constituent unit (a10) represented by the general formula (a10-1). (A1) The copolymer is preferably a copolymer having a structural unit (a11) in addition to the structural unit (a10), which further includes an aromatic ring (excluding aromatic rings to which a hydroxyl group is attached) in its side chain. Furthermore, component (A1) may also have other constituent units besides constituent units (a10) and (a11).

[0026] Regarding the constituent unit (a10): The constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[0027] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. x1is a single bond or a divalent linking group. Wa x1 is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more. ]

[0028] In the formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferable, a hydrogen atom or a methyl group is further preferable, and a hydrogen atom is particularly preferable.

[0029] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but examples of preferable ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like.

[0030] Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-] is more preferable.

[0031] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in is an aromatic ring which may have a substituent, from (n ax1A group with 1+1 hydrogen atoms removed is an example. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in this context is an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.) (n ax1 Another example is a group with (+1) hydrogen atoms removed. Among the above, Wa x1 Examples include benzene, naphthalene, anthracene, or biphenyl (n ax1 A group with (+1) hydrogen atoms removed is preferred, and (n ax1 A group with (+1) hydrogen atoms removed is more preferable, and from benzene (n ax1 A group with (+1) hydrogen atoms removed is even more preferable.

[0032] Wa x1 The aromatic hydrocarbon group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya x1 Examples of substituents for cyclic aliphatic hydrocarbon groups in are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. x1In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0033] In the above formula (a10-1), n ax1 is an integer greater than or equal to 1, preferably an integer between 1 and 10, more preferably an integer between 1 and 5, even more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0034] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] The constituent units (a10) of component (A1) may be one type or two or more types. The proportion of constituent units (a10) in component (A1) is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, even more preferably 65 to 100 mol%, and particularly preferably 70 to 100 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of the constituent unit (a10) above the lower limit, development characteristics and lithography characteristics are further improved. On the other hand, by setting it below the upper limit, it becomes easier to balance it with other constituent units.

[0039] Regarding the constituent unit (a11): Component (A1) is preferably a copolymer having, in addition to the above-mentioned structural unit (a10), a structural unit (a11) derived from a compound containing an aromatic ring (excluding aromatic rings to which a hydroxyl group is attached) in its side chain. Examples of compounds containing an aromatic ring (excluding aromatic rings to which a hydroxyl group is attached) in the side chain include, for example, the compound represented by the following general formula (a11-1).

[0040] [ka] [In formula (a11-1), Ra x2 Wa is a polymerizable group-containing group. x2 is, (n ax2 It is an aromatic hydrocarbon group with a +1) valency. However, Ra x2 and Wa x2 A fused ring structure may be formed. x02 Wa x2 This is a substituent that substitutes for a hydrogen atom constituting an aromatic hydrocarbon group. ax2 n is an integer between 0 and 3. ax2 If the number is 2 or more, multiple Ra x02 These elements may bond to each other to form a ring structure.

[0041] In the above formula (a11-1), Ra x2 This is a polymerizable group-containing group. Ra x2 In this context, a "polymerizable group" refers to a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and includes, for example, a group containing multiple bonds between carbon atoms, such as an ethylenic double bond. Examples of polymerizable groups include vinyl groups, allyl groups, acryloyl groups, methacryloyl groups, fluorovinyl groups, difluorovinyl groups, trifluorovinyl groups, difluorotrifluoromethylvinyl groups, trifluoroallyl groups, perfluoroallyl groups, trifluoromethylacryloyl groups, nonylfluorobutylacryloyl groups, vinyl ether groups, fluorinated vinyl ether groups, allyl ether groups, fluorinated allyl ether groups, styryl groups, vinylnaphthyl groups, fluorinated styryl groups, fluorinated vinylnaphthyl groups, norbornyl groups, fluorinated norbornyl groups, and silyl groups. The polymerizable group-containing group may be a group composed solely of a polymerizable group, or a group composed of a polymerizable group and other groups other than the polymerizable group. Examples of other groups other than the polymerizable group include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0042] Ra x2 For example, the chemical formula is CH2=C(R)-Ya x0 A group represented by - is preferably mentioned. In this chemical formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 It is a divalent linking group.

[0043] In the above formula (a11-1), Wa x2 is, (n ax2 It is an aromatic hydrocarbon group with a +1) valency, and Wa in (a10-1) x1 Similar examples include the above.

[0044] However, Ra x2 and Wa x2 A condensed ring structure may be formed. Ra x2 and Wa x2 When a condensed ring structure is formed with, the condensed ring structure contains Wa x2 It contains aromatic rings derived from Ra. x2The multiple bonds between carbon atoms in the polymerizable group derived from cleave to form the main chain of component (A1). In other words, some of the carbon atoms constituting the fused ring constitute the main chain of component (A1).

[0045] In the above formula (a11-1), Ra x02 Wa x2 These are substituents that substitute for hydrogen atoms that make up an aromatic hydrocarbon group. Ra x02 Examples of substituents in this compound include alkyl groups, alkoxy groups, and acyloxy groups. Ra x02 The alkyl group used as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Ra x02 The alkoxy group used as a substituent in is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, and particularly preferably a methoxy group or ethoxy group. Ra x02 The acyloxy group used as a substituent in the compound is preferably one with 2 to 6 carbon atoms, more preferably CH3C(=O)-O- (acetoxy group), more preferably C2H5C(=O)-O-, and particularly preferably CH3C(=O)-O- (acetoxy group).

[0046] In the above formula (a11-1), n ax2 is an integer between 0 and 3, preferably 0, 1, or 2, and more preferably 0 or 1. n ax2 If the number is 2 or more, multiple Ra x02 These may bond to each other to form a ring structure. The ring structure formed here may be a hydrocarbon ring or a heterocycle. For example, Wa x2 Two Ras bonded to the same aromatic ring in x02 And these two Ra x02 The aromatic ring to which it is attached (Wa x2 One example is a ring structure formed by one side (bond between carbon atoms) of a ) and a .

[0047] Suitable examples of such constituent units (a11) include those represented by the following general formulas (a11-u1-1) to (a11-u1-6).

[0048] [ka] [In the formula, R α R is a hydrogen atom, a methyl group, or a trifluoromethyl group. β n is an alkyl group, an alkoxy group, or an acyloxy group. ax2 n is an integer between 0 and 3. ax2 If there are 2 or more, multiple R β These elements may bond to each other to form a ring structure. 21 , n 22 , n 24 and n 25 Each of these is independently either 0 or 1. 23 and n 26 Each of these is independently either 1 or 2.

[0049] In the above equations (a11-u1-1)~(a11-u1-6), R β The alkyl group, alkoxy group, and acyloxy group in formula (a11-1) are Ra x02 The substituents in the above are the same as the alkyl groups, alkoxy groups, and acyloxy groups exemplified above.

[0050] The following are specific examples of constituent units (constituent unit (a11)) derived from the compound represented by the general formula (a11-1). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] Among the examples above, the constituent unit (a11) is preferably at least one selected from the group consisting of constituent units represented by general formulas (a11-u1-1) to (a11-u1-3), and the constituent unit represented by general formula (a11-u1-1) is more preferred. Among these, the constituent unit (a11) is preferably a constituent unit represented by any of the chemical formulas (a11-u1-11), (a11-u1-21), or (a11-u1-31).

[0057] The constituent units (a11) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a11), the proportion of constituent units (a11) in component (A1) is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, even more preferably 1 to 35 mol%, and particularly preferably 1 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of component unit (a11) above the lower limit, etching resistance and lithography characteristics are further improved. On the other hand, by setting it below the upper limit, it becomes easier to balance it with other component units.

[0058] <<Other constituent units>> Component (A1) may have other constituent units other than constituent unit (a10) and constituent unit (a11) (hereinafter also referred to as "constituent unit (a12)"). Compounds that derive the constituent unit (a12) include, for example, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having carboxyl groups and ester bonds, such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, adamantyl (meth)acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecyl (meth)acrylate, tetracyclodecyl Examples include alkyl (meth)acrylates such as siltetracyclododecyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; polymerizable compounds containing nitrile groups such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; polymerizable compounds containing amide bonds such as acrylamide and methacrylamide; and polymerizable compounds containing epoxy groups.

[0059] In particular, the constituent unit (a12) represented by the following general formula (a12-1) is more preferable.

[0060] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ra 12 It is an alkyl group.

[0061] In the above formula (a12-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. For R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and due to their industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a hydrogen atom is particularly preferred.

[0062] In the above formula (a12-1), Ra 12 Examples of alkyl groups in this context include linear or branched alkyl groups and cyclic alkyl groups. As for linear or branched alkyl groups, linear or branched alkyl groups having 1 to 5 carbon atoms are preferred, and methyl, ethyl, or butyl groups are more preferred. Preferred cyclic alkyl groups include cyclopentyl, cyclohexyl, adamantyl, norbornyl, isobornyl, tricyclodecyl, and tetracyclododecyltetracyclododecyl groups, with cyclohexyl or adamantyl groups being more preferred.

[0063] The constituent units (a12) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a12), the proportion of constituent units (a12) in component (A1) is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, even more preferably 1 to 35 mol%, and particularly preferably 1 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of the constituent unit (a12) above the lower limit, etching resistance and lithography characteristics are further improved. On the other hand, by setting it below the upper limit, it becomes easier to balance it with other constituent units.

[0064] In the resist composition of this embodiment, component (A) includes a polymer compound (A1) (component (A1)) having a constituent unit (a10). Preferred (A1) components include polymer compounds having at least one constituent unit (a10). Specifically, preferred examples include polymer compounds having a repeating structure of constituent unit (a10) (homopolymers consisting of constituent unit (a10)); polymer compounds having a repeating structure of constituent unit (a10) and constituent unit (a11); and polymer compounds having a repeating structure of constituent unit (a10) and constituent unit (a12).

[0065] In a polymer compound having a repeating structure of constituent units (a10) and constituent units (a11), the proportion of constituent units (a10) is preferably 50 to 99 mol%, more preferably 60 to 99 mol%, and even more preferably 70 to 99 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound. Furthermore, the proportion of constituent units (a11) in the polymer compound is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, and even more preferably 1 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0066] In a polymer compound having a repeating structure of constituent units (a10) and constituent units (a12), the proportion of constituent unit (a10) is preferably 50 to 99 mol%, more preferably 60 to 99 mol%, and even more preferably 70 to 99 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound. Furthermore, the proportion of constituent units (a12) in the polymer compound is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, and even more preferably 1 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0067] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 500 to 50000, more preferably 1000 to 30000, and even more preferably 1000 to 20000. If the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in the resist solvent for use as a resist, and if it is above the preferred lower limit of this range, the dry etching resistance and the cross-sectional shape of the resist pattern will be better.

[0068] (A1) The degree of dispersion of component (Mw / Mn) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.5. Mn represents the number-average molecular weight.

[0069] Such component (A1) can be produced by dissolving monomers that induce each constituent unit in a polymerization solvent and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the mixture and polymerizing it. Alternatively, such component (A1) can be produced by dissolving a monomer that induces the constituent unit (a10) and, if necessary, a monomer that induces a constituent unit other than the constituent unit (a10) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to this solution, polymerizing it, and then carrying out a deprotection reaction. Furthermore, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group at the terminal. Copolymers in which a hydroxyalkyl group, in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, are introduced are effective in reducing development defects and LER (line edge roughness: uneven unevenness of the line sidewall). Furthermore, component (A1) can also be produced by anionic polymerization using organoalkali metals such as n-butyllithium, s-butyllithium, t-butyllithium, ethyllithium, ethylsodium, 1,1-diphenylhexyllithium, and 1,1-diphenyl-3-methylpentyllithium as polymerization initiators.

[0070] (A2) About the ingredients The resist composition of this embodiment may also include, as component (A), a base component (hereinafter referred to as "component (A2)") that does not correspond to component (A1) and whose solubility in the developer changes due to the action of an acid. (A2) The component is not particularly limited and can be arbitrarily selected from a large number of components that have been conventionally known as base components for chemically amplified resist compositions. (A2) Component may be a single high-molecular-weight compound or a low-molecular-weight compound, or two or more may be used in combination.

[0071] The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may also be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, it becomes easier to form a resist pattern that is excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement.

[0072] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0073] ≪Onium-based acid generator (B1)≫ The (B1) component is not particularly limited, and any acid generators previously proposed for chemically amplified resist compositions can be used. Examples of the onium salt-based acid generators include a compound represented by the following general formula (b-1) (hereinafter also referred to as "(b-1) component"), a compound represented by the general formula (b-2) (hereinafter also referred to as "(b-2) component"), or a compound represented by the general formula (b-3) (hereinafter also referred to as "(b-3) component").

[0074] [Chemical formula] [In the formula, R 101 and R 104 ~R 108 are each independently a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. R 104 and R 105 may be bonded to each other to form a ring structure. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103 are each independently a single bond, an alkylene group or a fluorinated alkylene group. L 101 ~L 102 are each independently a single bond or an oxygen atom. L 103 ~L 105 are each independently a single bond, -CO- or -SO2-. m is an integer of 1 or more, and M m+ is an m-valent onium cation.]

[0075] {Anion part} ·Anion in the (b-1) component In formula (b-1), R 101 is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.

[0076] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0077] R 101 The aromatic hydrocarbon group in R is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring of the aromatic hydrocarbon group in R include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. R 101 Specific examples of the aromatic hydrocarbon group in R include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., such as arylalkyl groups). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0078] R 101 The cyclic aliphatic hydrocarbon group in R includes an aliphatic hydrocarbon group containing a ring in its structure. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0079] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, even more preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0080] The linear aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. Examples of linear aliphatic hydrocarbon groups include linear alkylene groups, specifically methylene groups [-CH2-], ethylene groups [-(CH2)2-], trimethylene groups [-(CH2)3-], tetramethylene groups [-(CH2)4-], pentamethylene groups [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6, even more preferably 3 or 4, and most preferably 3. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0081] Also, R 101 The cyclic hydrocarbon group in this formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the following general formulas (b2-r-1) to (b2-r-7), -SO2--containing cyclic groups represented by the following general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In this case, in the chemical formulas (r-hr-1) to (r-hr-16), * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0082] [ka] [In the formula, Rb' 21 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, where n' is an integer from 0 to 2, and m' is 0 or 1. * indicates a bond.

[0083] In the general formulas (b2-r-1) to (b2-r-7), Rb' 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Rb' 21 The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Rb' 21 Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). Rb' 21 In this mixture, a fluorine atom is preferred as the halogen atom. Rb' 21 The halogenated alkyl group in is the aforementioned Rb' 21 Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl group, and perfluoroalkyl groups are particularly preferred.

[0084] Rb' 21 In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' can be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R'' is a linear or branched alkyl group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. When R'' is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to those represented by the general formulas (b2-r-1) to (b2-r-7) mentioned above. Rb' 21 The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Rb' 21 Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0085] Rb' 21 Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0086] In the general formulas (b2-r-2), (b2-r-3), and (b2-r-5) above, the alkylene group having 1 to 5 carbon atoms in B'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, or isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, or -CH2-S-CH2-. B'' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0087] [ka] [In the formula, Rb' 51 Each of the following is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO2--containing cyclic group; B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer from 0 to 2. * indicates a bond.

[0088] In the above general formulas (b5-r-1) to (b5-r-2), B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, or an oxygen atom or a sulfur atom. For B'', an alkylene group or -O- having 1 to 5 carbon atoms is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is even more preferred.

[0089] In the above general formulas (b5-r-1) to (b5-r-4), Rb' 51Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group, and among them, each is preferably independently a hydrogen atom or a cyano group.

[0090]

Chemical formula

[0091] R 101 Examples of the substituent in the cyclic group of R include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, etc. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group are most preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferable. Examples of the halogenated alkyl group as a substituent include a group in which a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., are substituted with the above halogen atoms. The carbonyl group as a substituent is a group that substitutes the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0092] R 101The cyclic hydrocarbon group in [substance] may be a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the condensed ring include those in which one or more aromatic rings are condensed to a polycycloalkane having a bridged ring system polycyclic skeleton, and the like. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the condensed cyclic group, a group containing a condensed ring in which two or three aromatic rings are condensed to a bicycloalkane is preferable, and a group containing a condensed ring in which two or three aromatic rings are condensed to bicyclo[2.2.2]octane is more preferable. R 101 Specific examples of the condensed cyclic group in [substance] include those represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents a bond that binds to Y in formula (b-1). 101

[0093] [Chemical formula]

[0094] R 101 Examples of the substituent that the condensed cyclic group in [substance] may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and the like. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the condensed cyclic group are the same as those listed as the substituent of the cyclic group in the above R 101 [substance]. Examples of the aromatic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from an aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), and heterocyclic groups respectively represented by the above formulas (r-hr-1) to (r-hr-6). ​Examples of alicyclic hydrocarbon groups as substituents on the fused cyclic group include: groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (b2-r-1) to (b2-r-7); -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4); and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16).

[0095] Chain-like alkyl groups that may have substituents: R 101 The chain-like alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0096] A chain-like alkenyl group which may have substituents: R 101 The linear alkenyl group may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0097] R 101 Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R 101 Examples include cyclic groups in this context.

[0098] Among the above, R 101 The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically as a cyclic hydrocarbon group, preferred are a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (b2-r-1) to (b2-r-7), respectively; a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), respectively; a group obtained by removing one or more hydrogen atoms from a polycycloalkane or a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), respectively; and an adamantyl group or a -SO2-containing cyclic group represented by the general formula (b5-r-1), respectively.

[0099] If the cyclic hydrocarbon group has substituents, the substituents are preferably hydroxyl groups.

[0100] In formula (b-1), Y 101 It is a single bond or a divalent linking group containing an oxygen atom. Y 101 If Y is a divalent linking group containing an oxygen atom, 101 It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bond: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-OC(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-OC(=O)-O-); and combinations of such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups containing an oxygen atom include the linking groups represented by the following general formulas (y-al-1) to (y-al-7). Note that in the following general formulas (y-al-1) to (y-al-7), R in formula (b-1) above 101 The V' in the following general formulas (y-al-1)~(y-al-7) is what combines with it. 101 That is the case.

[0101] [ka] [In the formula, V' 101 V' is a single bond or an alkylene group with 1 to 5 carbon atoms. 102 It is a divalent saturated hydrocarbon group with 1 to 30 carbon atoms.

[0102] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0103] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V' 102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 3 A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0104] Y 101 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably the linking groups represented by the above formulas (y-al-1) to (y-al-5).

[0105] In formula (b-1), V 101 This is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in this product preferably have 1 to 4 carbon atoms. 101 As for the fluorinated alkylene group in V 101Examples thereof include a group in which some or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms. Among them, V 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0106] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0107] Specific examples of the anion part represented by the formula (b-1) include, for example, when Y 101 is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; when Y 101 is a divalent linking group containing an oxygen atom, anions represented by any of the following formulas (an-1) to (an-4).

[0108]

Chemical formula

[0109] R" 101 , R” 102 and R” 103 The aliphatic cyclic group which may have substituents is R in formula (b-1) above. 101 It is preferable that the substituent is the group exemplified as a cyclic aliphatic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the cyclic aliphatic hydrocarbon group in the above.

[0110] R" 103 The aromatic cyclic group which may have substituents in formula (b-1) is R 101 It is preferable that the substituent is the aromatic hydrocarbon group exemplified in the cyclic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the aromatic hydrocarbon group in the above.

[0111] R" 101 The chain-like alkyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkyl group in the compound. R" 103 The chain-like alkenyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkenyl group in the formula.

[0112] R" 104The fluorinated alkyl group in is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched perfluoroalkyl group having 1 to 5 carbon atoms, and even more preferably a nonafluorobutyl group.

[0113] • Anion in component (b-2) In formula (b-2), R 104 , R 105 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). 101 Similar examples can be given. However, R 104 , R 105 These may be bonded to each other to form a ring. R 104 , R 105 The alkyl group is preferably a linear alkyl group which may have substituents, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. 104 , R 105 The number of carbon atoms in the chain-like alkyl group is preferably small within the above range of carbon atoms, for reasons such as good solubility in the resist solvent. 104 , R 105 In the chain-like alkyl group, a larger number of hydrogen atoms substituted with fluorine atoms is preferable because it increases the acid strength and improves transparency to high-energy light and electron beams below 250 nm. The proportion of fluorine atoms in the chain-like alkyl group, i.e., the fluorination rate, is preferably 70-100%, more preferably 90-100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). 101 Similar examples include the above. In formula (b-2), L 101 , L 102 Each of these is either a single bond or an oxygen atom, independently of the others.

[0114] • Anion in component (b-3) In formula (b-3), R 106 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). 101 Similar examples include the above. In formula (b-3), L 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-.

[0115] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B). Among these, an anion represented by any of the above general formulas (an-1) to (an-3) is more preferred, an anion represented by either general formula (an-1) or (an-2) is even more preferred, and an anion represented by general formula (an-2) is particularly preferred.

[0116] {cation part} In the above equations (b-1), (b-2), and (b-3), M m+ This represents an onium cation with an m-valence. Among these, sulfonium cations and iodonium cations are preferred. m is an integer greater than or equal to 1.

[0117] Preferred cation portion ((M m+ ) 1 / m Examples of organic cations include those represented by the following general formulas (ca-1) to (ca-5).

[0118] Among the above, the cation part ((Mm+ ) 1 / m The cation represented by the general formula (ca-1) is preferred.

[0119] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 These atoms may bond to each other to form a ring with the sulfur atom in the formula. 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted SO2-containing cyclic group. 201 This represents -C(=O)- or -C(=O)-O-. 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. x is either 1 or 2. W 201 This represents a (x+1) valence linking group.

[0120] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 201 ~R 207 , and R 211 ~R 212 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R201 ~R 207 , and R 211 ~R 212 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the general formulas (ca-r-1) to (ca-r-7) above.

[0121] In the above general formulas (ca-1) to (ca-5), R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 When these atoms bond to each other and form a ring with the sulfur atom in the formula, they may be heteroatoms such as sulfur, oxygen, or nitrogen atoms, or carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R N is an alkyl group having 1 to 5 carbon atoms. ) may be bonded via functional groups such as ). The formed ring preferably has 3 to 10 members, and most preferably 5 to 7 members, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyine ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0122] R 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. If an alkyl group is formed, it may bond with other elements to form a ring.

[0123] R 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted SO2-containing cyclic group. R 210 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 210 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 210 In this context, the SO2-containing cyclic group which may have substituents is preferably a "-SO2-containing polycyclic group," and more preferably a group represented by the general formula (b5-r-1).

[0124] Y 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the above formula (b-1) is R 101 An example of an aromatic hydrocarbon group in this context is the aryl group exemplified above, with one hydrogen atom removed. Y 201 The alkylene group and alkenylene group in the above formula (b-1) are R 101 Examples of the chain-like alkyl groups and chain-like alkenyl groups mentioned above include groups obtained by removing one hydrogen atom from the examples provided.

[0125] In the above equation (ca-4), x is either 1 or 2. W 201 This is a (x+1) valence, i.e., a divalent or trivalent linking group. W 201 In this, the divalent linking group is preferably a divalent hydrocarbon group which may have substituents, and Lz in the general formula (z-1) described later. 1 Examples of divalent hydrocarbon groups that may have substituents, similar to the above, can be given. 201The divalent linking group in this compound may be linear, branched, or cyclic, with cyclic being preferred. Among these, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of arylene groups include phenylene groups and naphthylene groups, with phenylene groups being particularly preferred. W 201 The trivalent linking group in is the aforementioned W 201 Examples include a group obtained by removing one hydrogen atom from a divalent linking group, and a group in which another divalent linking group is bonded to the aforementioned divalent linking group. 201 In this compound, a trivalent linking group is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0126] Specific examples of suitable cations represented by the above formula (ca-1) include the cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0127] [ka]

[0128] [ka]

[0129] [ka] [In the formula, g1, g2, and g3 represent the number of repetitions, where g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[0130] [ka]

[0131] [ka]

[0132] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the aforementioned R 201 ~R 207 , and R 210 ~R 212 These are the same as those listed as substituents that may be present.

[0133] Suitable cations represented by the formula (ca-2) include, specifically, diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0134] Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0135] [ka]

[0136] Specific examples of suitable cations represented by the above formula (ca-4) include the cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0137] [ka]

[0138] Specific examples of suitable cations represented by the above formula (ca-5) include the cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0139] [ka]

[0140] Among the above, the cation part ((M m+ ) 1 / mThe cation represented by the general formula (ca-1) is preferred.

[0141] In this embodiment, component (B1) preferably contains an acid generator (B1-1) represented by the following general formula (b1-1).

[0142] [ka] [In the formula, Rb 201 ~Rb 203 Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~R 203 These may bond to each other to form a ring with the sulfur atom in the formula. - It is an anti-anion.

[0143] In the above formula (b1-1), Rb 201 ~Rb 203 R in the above formula (ca-1) is 201 ~R 203 It is similar to the above. In particular, Rb 201 ~Rb 203 However, each may independently have a substituent on an aryl group, or Rb 201 Rb is an aryl group which may have substituents. 202 and Rb 203 It is preferable that they bond to each other and form a ring together with the sulfur atom in the formula, Rb 201 Rb is an aryl group which may have substituents. 202 and Rb 203 It is more preferable that they bond to each other and form a ring with the sulfur atom in the formula, Rb 201 Rb is an aryl group which may have substituents. 202 and Rb 203 It is even more preferable that these atoms bond to each other to form a tetrahydrothiophenium ring or a tetrahydrothiopyranium ring together with the sulfur atom in the formula.

[0144] In the above formula (b1-1), X -The counter anions in are preferably the anion of component (b-1), the anion of component (b-2), and the anion of component (b-3), more preferably the anion of component (b-1), even more preferably an anion represented by any of the formulas (an-1) to (an-4), and even more preferably an anion represented by formula (an-1) or (an-4).

[0145] In the resist composition of this embodiment, component (B1) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (B1) is preferably 50 parts by mass or less, more preferably 0.1 to 40 parts by mass, even more preferably 0.1 to 30 parts by mass, and particularly preferably 0.1 to 20 parts by mass, per 100 parts by mass of component (A1). (B1) By setting the content of component B1 within the above preferred range, sufficient pattern formation is achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, which is preferable because it results in good storage stability for the resist composition.

[0146] <(C) component> (C) Component is at least one crosslinking agent selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluryl-based crosslinking agents, and epoxy-based crosslinking agents.

[0147] Examples of melamine-based crosslinking agents include compounds obtained by reacting melamine with formaldehyde and substituting the hydrogen atoms of the amino group with hydroxymethyl groups, and compounds obtained by reacting melamine with formaldehyde and a lower alcohol and substituting the hydrogen atoms of the amino group with lower alkoxymethyl groups. Specifically, examples include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, and hexasubtoxicbutylmelamine, among which hexamethoxymethylmelamine is preferred.

[0148] Examples of urea-based crosslinking agents include compounds obtained by reacting urea with formaldehyde and substituting the hydrogen atoms of the amino group with hydroxymethyl groups, and compounds obtained by reacting urea with formaldehyde and a lower alcohol and substituting the hydrogen atoms of the amino group with lower alkoxymethyl groups. Specifically, examples include bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, and bisbutoxymethylurea, with bismethoxymethylurea being preferred.

[0149] Examples of alkylene urea-based crosslinking agents include compounds represented by the following general formula (CA-1).

[0150] [ka] [In formula (CA-1), Rc 1 and Rc 2 Each of these is independently a hydroxyl group or a lower alkoxy group, and Rc 3 and Rc 4 Each of these is independently a hydrogen atom, a hydroxyl group, or a lower alkoxy group, and vc is an integer between 0 and 2.

[0151] Rc 1 and Rc 2 When Rc is a lower alkoxy group, it is preferably an alkoxy group having 1 to 4 carbon atoms, and may be linear or branched. 1 and Rc 2 They may be the same, or they may be different from each other. It is more preferable that they are the same. Rc 3 and Rc 4 When Rc is a lower alkoxy group, it is preferably an alkoxy group having 1 to 4 carbon atoms, and may be linear or branched. 3 and Rc 4 They may be the same, or they may be different from each other. It is more preferable that they are the same. vc is an integer between 0 and 2, preferably 0 or 1. As alkylene urea crosslinking agents, compounds with a vc of 0 (ethylene urea crosslinking agents) and / or compounds with a vc of 1 (propylene urea crosslinking agents) are particularly preferred.

[0152] The compound represented by the above general formula (CA-1) can be obtained by condensing alkylene urea with formalin, and then by reacting the resulting product with a lower alcohol.

[0153] Specific examples of alkylene urea-based crosslinking agents include, for example, ethylene urea-based crosslinking agents such as mono and / or dihydroxymethylated ethylene urea, mono and / or dimethoxymethylated ethylene urea, mono and / or diethoxymethylated ethylene urea, mono and / or dipropoxymethylated ethylene urea, and mono and / or dibutoxymethylated ethylene urea; propylene urea-based crosslinking agents such as mono and / or dihydroxymethylated propylene urea, mono and / or dimethoxymethylated propylene urea, mono and / or diethoxymethylated propylene urea, mono and / or dipropoxymethylated propylene urea, and mono and / or dibutoxymethylated propylene urea; and 1,3-di(methoxymethyl)4,5-dihydroxy-2-imidazolidinone, 1,3-di(methoxymethyl)-4,5-dimethoxy-2-imidazolidinone, etc.

[0154] Examples of glycoluryl crosslinking agents include glycoluryl derivatives in which the N position is substituted with one or both of a hydroxyalkyl group and / or an alkoxyalkyl group having 1 to 4 carbon atoms. Such glycoluryl derivatives can be obtained by condensing glycoluryl with formalin, and by reacting the resulting product with a lower alcohol. Specific examples of glycoluryl crosslinking agents include, for example, mono, di, tri and / or tetrahydroxymethylated glycoluryl; mono, di, tri and / or tetramethoxymethylated glycoluryl; mono, di, tri and / or tetraethoxymethylated glycoluryl; mono, di, tri and / or tetrapropoxymethylated glycoluryl; and mono, di, tri and / or tetrabutoxymethylated glycoluryl.

[0155] The epoxy crosslinking agent is not particularly limited as long as it has epoxy groups, and can be arbitrarily selected and used. Among these, those having two or more epoxy groups are preferred. Having two or more epoxy groups improves the crosslinking reactivity. The number of epoxy groups is preferably two or more, more preferably two to four, and most preferably two. The following are suitable epoxy crosslinking agents.

[0156] [ka]

[0157] In particular, as component (C), a crosslinking agent having a -NCH2-OCH3 group is preferred, more preferably a crosslinking agent selected from the group consisting of compounds represented by the following formulas (c1-1) or (c1-2), compounds having a -NCH2-OCH3 group and a melamine skeleton, and mono, di, tri and / or tetramethoxymethylated glycoluryl, and even more preferably a crosslinking agent selected from the group consisting of compounds having a -NCH2-OCH3 group and a melamine skeleton, and mono, di, tri and / or tetramethoxymethylated glycoluryl.

[0158] [ka] [In the formula, nc1 and nc2 are each independent integers between 1 and 3.]

[0159] (C) Component may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (C) is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, even more preferably 3 to 30 parts by mass, and most preferably 5 to 25 parts by mass, per 100 parts by mass of component (A1). (C) When the content of component (C) is above the lower limit, crosslinking proceeds sufficiently, and resolution performance and lithography characteristics are further improved. In addition, a good resist pattern with less swelling can be obtained. If the content is below this upper limit, the storage stability of the resist composition is good, and the deterioration of sensitivity over time is easily suppressed.

[0160] <(Z) component> Component (Z) is a polynuclear phenol low molecular weight compound having 5 or fewer phenyl groups, preferably a polynuclear phenol low molecular weight compound having 2 to 5 phenyl groups, and more preferably a polynuclear phenol low molecular weight compound having 3 to 4 phenyl groups. When the (Z) component has 2 to 5 phenyl groups, the transmittance of the resist film to the exposure light source tends to be good when forming a thick resist pattern, and resolution tends to be good. In addition, when the (Z) component has 2 to 5 phenyl groups, the occurrence of cracks in the thick resist pattern tends to be reduced.

[0161] The number of phenolic hydroxyl groups in component (Z) is not particularly limited, but from the viewpoint of improving lithography characteristics such as resolution and DOF, 2 to 5 are preferred, and 3 to 4 are more preferred.

[0162] In this embodiment, component (Z) preferably contains a compound represented by the following general formula (z-1).

[0163] [ka] [In the formula, Rz 1 and Rz 2n1 and n2 are independent substituents. Lz are independent integers between 0 and 4. 1 Rz is a single bond or a divalent linking group. 0 Rz is a hydrocarbon group which may have substituents. 4 [This is a hydrogen atom or an alkyl group.]

[0164] In the above equation (z-1), Rz 1 and Rz 2 Substituents in include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, and aryl groups. Among these, Rz 1 and Rz 2 Preferably, the substituent in is an alkyl group, more preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group.

[0165] In the above formula (z-1), n1 and n2 are each an independent integer between 0 and 4, preferably between 0 and 3. From the viewpoint of increasing sensitivity, it is preferable that n1 and n2 are each an independent integer between 1 and 3.

[0166] In the above formula (z-1), Lz 1 The divalent linking group in this is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have substituents, a divalent linking group which contains a heteroatom, and so on.

[0167] • Divalent hydrocarbon groups which may have substituents: Lz 1 If is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0168] ··Lz 1 Aliphatic hydrocarbon groups in An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferable to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0169] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0170] The linear or branched aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0171] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0172] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are even more preferred. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like, with fluorine atoms being preferred. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0173] ··Lz 1 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this carbon number does not include the carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as benzyl group, phenethyl group, cumyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0174] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0175] • Divalent linking groups containing heteroatoms: Lz 1When is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - is represented by the base [wherein Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents independently, O is an oxygen atom, and m'' is an integer from 0 to 3. When the divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - Middle, Y 21 and Y 22Each of these is independently a divalent hydrocarbon group which may have substituents. The divalent hydrocarbon group is the Lz group. 1 Examples include those similar to the divalent linking groups (divalent hydrocarbon groups that may have substituents) mentioned in the description of divalent linking groups in [the relevant section]. Y 21 Preferably, the group is a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22 The group is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula - [Y 21 -C(=O)-O] m” -Y 22 In the base represented by -, m'' is an integer between 0 and 3, preferably between 0 and 2, more preferably 0 or 1, and particularly preferably 1. That is, in the formula -[Y 21 -C(=O)-O] m” -Y 22 As a base represented by -, formula -Y 21 -C(=O)-OY 22 Groups represented by - are particularly preferred. Among them, the group represented by formula -(CH2) a’ -C(=O)-O-(CH2) b’ A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0176] Among the above, Lz 1Preferably, the group is a single-bonded, linear or branched aliphatic hydrocarbon group or aromatic hydrocarbon group, more preferably a single-bonded, linear alkylene group or aryl group having 1 to 10 carbon atoms, in which one hydrogen atom of the alkylene group having 1 to 4 carbon atoms is substituted with an alkylene group having 1 to 4 carbon atoms, and even more preferably a single-bonded, linear alkylene group having 1 to 4 carbon atoms, or a benzyl group, phenethyl group, or cumyl group from which one more hydrogen atom has been removed. From the viewpoint of reducing crack occurrence in thick film resist patterns, Lz 1 A linear alkylene group having 1 to 4 carbon atoms is preferred.

[0177] In the above equation (z-1), Rz 0 Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0178] Rz 0 The linear alkyl group in this compound preferably has 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc.

[0179] Rz 0 The branched alkyl group in this compound preferably has 3 to 10 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, and 2,2-dimethylbutyl group.

[0180] Rz 0 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0181] Rz 0 Aromatic hydrocarbon groups in this context include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring with 5 to 30 carbon atoms. Among them, Rz 0 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from benzene or naphthalene with one or more hydrogen atoms removed; and most preferably a group from benzene with one or more hydrogen atoms removed.

[0182] Rz 0 The substituents that the hydrocarbon group in Rz may have include hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups (methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), alkyloxycarbonyl groups, etc. Among these, Rz 0 A hydroxyl group is a preferred substituent that the hydrocarbon group in the compound may have.

[0183] In the above equation (z-1), Rz 4 The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.

[0184] In this embodiment, component (Z) more preferably contains a compound represented by the following general formula (z-1-1).

[0185] [ka] [In the formula, Rz1 , Rz 2 and Rz 3 n1, n2, and n3 are each independent substituents. Lz 1 Rz is a single bond or a divalent linking group. 4 [This is a hydrogen atom or an alkyl group.]

[0186] In the above equation (z-1-1), Rz 1 , Rz 2 and Rz 3 The substituent in is Rz in formula (z-1) above. 1 and Rz 2 This is similar to the substituents in [the given expression]. In the above formula (z-1-1), n1, n2, and n3 are each an independent integer between 0 and 4, preferably between 0 and 3. From the viewpoint of increasing sensitivity, it is preferable that n1, n2, and n3 are each an independent integer between 1 and 3. In the above formula (z-1), Lz 1 and Rz 4 This is Lz in the above equation (z-1). 1 and Rz 4 It is similar to that.

[0187] The following are some preferred examples of component (Z).

[0188] [ka]

[0189] The (Z) component contained in the resist composition of this embodiment may be used alone or in combination of two or more types.

[0190] In the resist composition of this embodiment, the content of component (Z) is preferably 0.1 to 35 parts by mass, more preferably 0.3 to 30 parts by mass, even more preferably 0.5 to 25 parts by mass, and particularly preferably 1 to 20 parts by mass, per 100 parts by mass of component (A1). When the content of component (Z) is above the lower limit of the preferred range described above, crack formation in thick-film resist patterns is more easily reduced. On the other hand, when the content of component (Z) is below the upper limit of the preferred range described above, lithography characteristics such as resolution and DOF are more easily improved.

[0191] <Optional ingredients> ≪(D) ​​Component≫ In this embodiment, the resist composition may further contain an acid diffusion control agent component (hereinafter referred to as "component (D)") in addition to components (A), (B), (C), and (Z). Component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Examples of component (D) include nitrogen-containing organic compounds (D1) (hereinafter referred to as "component (D1)") and photodegradable bases (D2) that do not fall under component (D1) and decompose upon exposure, losing their acid diffusion control properties (hereinafter referred to as "component (D2)"). (D) By using a resist composition containing component D, the contrast between the exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. As for component (D), component (D1) is preferred from the viewpoint of improving the transmittance of the resist film to the exposure light source when forming a thick resist pattern.

[0192] • About the (D1) component Component (D1) is a basic component, a nitrogen-containing organic compound component that acts as an acid diffusion control agent in the resist composition.

[0193] The (D1) component is not particularly limited as long as it acts as an acid diffusion control agent, and examples include aliphatic amines and aromatic amines.

[0194] Among aliphatic amines, secondary and tertiary aliphatic amines are preferred. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic groups have 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia (NH3) is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine are particularly preferred.

[0195] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. These heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Examples of aliphatic monocyclic amines include piperidine and piperazine. As aliphatic polycyclic amines, those having 6 to 10 carbon atoms are preferred, and specifically include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0196] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc., with triethanolamine triacetate being preferred.

[0197] Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, tripenzylamine, aniline compounds, and N-tert-butoxycarbonylpyrrolidine.

[0198] (D1) Component may be used alone or in combination of two or more types. (D1) Among the above, aromatic amines are preferred for component (D1), and aniline compounds are more preferred. Examples of aniline compounds include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline.

[0199] • About the (D2) component The (D2) component is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of the compound represented by the following general formula (d2-1) (hereinafter referred to as "component (d2-1)"), the compound represented by the following general formula (d2-2) (hereinafter referred to as "component (d2-2)"), and the compound represented by the following general formula (d2-3) (hereinafter referred to as "component (d2-3)"). Components (d2-1) to (d2-3) decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), so they do not act as a quencher, but they act as a quencher in the unexposed areas of the resist film.

[0200] [ka] [In the formula, Rd 1 ~Rd 4 Rd in general formula (d2-2) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 2 In this example, assume that no fluorine atoms are bonded to carbon atoms adjacent to the sulfur atom. 1 is a single bond or a divalent linking group. m is an integer greater than or equal to 1, and M' m+ These are each independently m-valent onium cations.

[0201] {(d2-1) component} · Anion Club In formula (d2-1), Rd 1 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of these is R 101 Examples include those similar to the above. Among these, Rd 1 Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated via alkylene groups, and in this case, preferred substituents are the linking groups represented by the general formulas (y-al-1) to (y-al-5). Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (for example, a polycyclic structure consisting of a bicyclooctane skeleton ring structure and other ring structures). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The linear alkyl group preferably has 1 to 10 carbon atoms, and specifically includes linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

[0202] When the chain-like alkyl group is a fluorinated alkyl group having a fluorinated atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine. Examples of atoms other than fluorine include oxygen atoms, sulfur atoms, nitrogen atoms, and the like. Rd 1 Preferably, the linear alkyl group is a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms, and particularly preferably, the linear alkyl group is a fluorinated alkyl group (linear perfluoroalkyl group) in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms.

[0203] The following are some preferred specific examples of the anionic portion of component (d2-1).

[0204] [ka]

[0205] • Cation section In formula (d2-1), M' m+ This is an onium cation with an oval value. M' m+ Suitable onium cations include those similar to those represented by the general formulas (ca-1) to (ca-4), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149) being even more preferred. (d2-1) Component may be used alone or in combination of two or more types.

[0206] {(d2-2) component} · Anion Club In formula (d2-2), Rd 2 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 101 Examples include those similar to the above. However, Rd 2 In this example, the carbon atom adjacent to the S atom is assumed to be unbonded to a fluorine atom (not fluorine-substituted). This results in the (d2-2) component anion becoming a moderately weak acid anion, improving the quenching ability of the (D2) component. Rd 2 Preferably, the group is a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents. The chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group preferably has one or more hydrogen atoms removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have substituents); more preferably has one or more hydrogen atoms removed from camphor, etc. Rd 2 The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d2-1). 1 Examples of substituents that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above are similar to those mentioned above.

[0207] The following are some preferred specific examples of the anionic portion of component (d2-2).

[0208] [ka]

[0209] • Cation section In formula (d2-2), M' m+ This is an m-valent onium cation, and M' in formula (d2-1) above. m+ It is similar to that. (d2-2) Component may be used individually or in combination of two or more.

[0210] {(d2-3) component} · Anion Club In formula (d2-3), Rd 3 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 101 Examples include those similar to the above, and it is preferable that they are cyclic groups containing a fluorine atom, linear alkyl groups, or linear alkenyl groups. Among these, fluorinated alkyl groups are preferred, and the above Rd 1 A fluorinated alkyl group similar to the one shown is more preferable.

[0211] In formula (d2-3), Rd 4 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 101 Examples include those similar to the above. In particular, alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups, which may have substituents, are preferred. Rd 4 The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. 4Some of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, cyano groups, etc. Rd 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of alkoxy groups having 1 to 5 carbon atoms include the methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, and tert-butoxy group. Among these, the methoxy group and ethoxy group are preferred.

[0212] Rd 4 The alkenyl group in formula (b-1) is R 101 Examples include those similar to the above, with vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups being preferred. These groups may further have a C1-C5 alkyl group or a C1-C5 halogenated alkyl group as substituents.

[0213] Rd 4 The cyclic group in is R in formula (b-1) above. 101 Examples include those similar to the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, or aromatic groups such as phenyl groups and naphthyl groups. 4 When the group is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties.

[0214] In formula (d2-3), Yd 1 It is a single bond or a divalent linking group. Yd 1 The divalent linking group in formula (a10-1) is not particularly limited, but may include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. These are, respectively, Ya in formula (a10-1) above. x1 Examples include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms, as mentioned in the explanation of divalent linking groups in [reference]. Yd1 The preferred members are carbonyl groups, ester bonds, amide bonds, alkylene groups, or combinations thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0215] The following are preferred specific examples of the anionic portion of component (d2-3).

[0216] [ka]

[0217] [ka]

[0218] • Cation section In formula (d2-3), M' m+ This is an m-valent onium cation, and M' in formula (d2-1) above. m+ It is similar to that. (d2-3) Components may be used individually or in combination of two or more.

[0219] Component (D2) may consist of only one of the above components (d2-1) to (d2-3), or it may consist of a combination of two or more components. If the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.5 to 35 parts by mass, more preferably 1 to 25 parts by mass, even more preferably 2 to 20 parts by mass, and particularly preferably 3 to 15 parts by mass, per 100 parts by mass of component (A). When the content of component (D2) is above the preferred lower limit, particularly good lithography characteristics and resist pattern shapes are easily obtained. On the other hand, when it is below the upper limit, a balance with other components can be achieved, resulting in good lithography characteristics across various categories.

[0220] (D2) Method for producing component: The methods for producing the aforementioned components (d2-1) and (d2-2) are not particularly limited and can be produced by known methods. Furthermore, the method for producing component (d2-3) is not particularly limited and may be, for example, similar to the method described in US2012-0149916.

[0221] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and their derivatives>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives (hereinafter referred to as "component (E)"). Examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, among which salicylic acid is preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred among these. Examples of derivatives of phosphorus oxoacids include esters obtained by substituting the hydrogen atoms of the above oxoacid with hydrocarbon groups, and examples of hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.

[0222] In the resist composition of this embodiment, component (E) may be used alone or in combination of two or more types. If the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of component (A). By setting the content within the above range, the lithography characteristics are further improved.

[0223] ≪Fluorine additive component (F)≫ The resist composition in this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as the hydrophobic resin. Component (F) is used to impart water repellency to the resist film and, by being used as a separate resin from component (A), improves lithography properties. As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically, component (F) includes polymers having a constituent unit (f1) represented by the following general formula (f1-1). This polymer is preferably a polymer (homopolymer) consisting only of the constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); and more preferably a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, and more preferably a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[0224] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 They may be the same or different. 1 Rf is an integer between 0 and 5. 101 It is an organic group containing a fluorine atom.

[0225] In formula (f1-1), R bonded to the α-carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 A fluorine atom is preferred as the halogen atom. Rf 102 and Rf 103 Examples of alkyl groups having 1 to 5 carbon atoms in R include those similar to the alkyl groups having 1 to 5 carbon atoms in R above, with methyl or ethyl groups being preferred. 102 and Rf 103 Specifically, examples of halogenated alkyl groups having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Fluorine atoms are preferred as the halogen atoms, particularly Rf. 102 and Rf 103 Preferably, the element is a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms; more preferably, a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group; and even more preferably, a hydrogen atom. In formula (f1-1), nf 1 is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0226] In formula (f1-1), Rf 101 This is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing fluorine atoms may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, in hydrocarbon groups containing fluorine atoms, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 More preferably, fluorinated hydrocarbon groups having 1 to 6 carbon atoms are used, with trifluoromethyl groups, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, and -CH2-CH2-CF2-CF2-CF2-CF3 being particularly preferred.

[0227] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If it is below the upper limit of this range, it has sufficient solubility in resist solvents for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. The degree of dispersion of component (F) (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0228] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. If the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A).

[0229] ≪Organic solvent component (S)≫ The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). The (S) component can be any solvent that can dissolve each component used to form a homogeneous solution, and any solvent that is conventionally known as a solvent for chemically amplified resist compositions can be appropriately selected and used. (S) components include, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having ester bonds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of the aforementioned polyhydric alcohols or compounds having ester bonds; etc. Examples include derivatives of polyhydric alcohols [of which propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0230] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility of PGMEA and the polar solvent, but it is preferably in the range of 1:9 to 9:1, and more preferably in the range of 2:8 to 8:2. More specifically, when EL or cyclohexanone is used as the polar solvent, the mass ratio of PGMEA to EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is used as the polar solvent, the mass ratio of PGMEA to PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Furthermore, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5.

[0231] The amount of component (S) used is set so that the solid content concentration of the resist composition is 15% by mass or more. In this specification, the solid content in the resist composition refers to components other than component (S). The solid content concentration of the resist composition is calculated by the following formula. Solid content concentration (mass%) = Total mass of components other than (S) / Total mass of resist composition × 100

[0232] For example, if the resist composition consists of components (A), (Z), (B), (D), and (S), the solid content concentration (mass%) = [((A) component + (Z) component + (B) component + (D) component) / ((A) component + (Z) component + (B) component + (D) component) + (S) component] × 100.

[0233] By setting the solid content concentration of the resist composition to 15% by mass or more, a thick resist film (for example, a film thickness of 2 μm to 20 μm) can be formed when the resist composition is applied to a substrate to form a resist film. The solid content concentration of the resist composition is not particularly limited as long as it is 15% by mass or more, and can be appropriately determined according to the desired film thickness of the resist film. Generally, the higher the solid content concentration, the thicker the resist film becomes. The upper limit of the solid content concentration of the resist composition is not particularly limited as long as the solid content is at a concentration in which it can be dissolved. The solid content concentration of the resist composition is, for example, 60% by mass or less, preferably 55% by mass or less, and more preferably 50% by mass or less. Examples of solid content concentrations in the resist composition include 15-60% by mass, 15-55% by mass, or 15-50% by mass.

[0234] The resist composition of this embodiment may further contain, if desired, miscible additives such as additional resins to improve the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc.

[0235] The resist composition of this embodiment may be subjected to removal of impurities after dissolving the resist material in component (S), using a polyimide porous membrane, a polyamide-imide porous membrane, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous membrane, a filter made of a polyamide-imide porous membrane, or a filter made of a polyimide porous membrane and a polyamide-imide porous membrane. Examples of the polyimide porous membrane and the polyamide-imide porous membrane include those described in Japanese Patent Application Publication No. 2016-155121.

[0236] The resist composition of this embodiment described above has a solid content concentration of 15% by mass or more and contains a polynuclear phenol low molecular weight compound (Z) (component (Z)) having 5 or fewer phenyl groups. Since the resist composition of this embodiment has a solid content concentration of 15% by mass or more, when it is applied to a substrate to form a resist film, a thick resist film (for example, a film thickness of 2 μm to 20 μm) is formed. In such a thick resist film, cracks are likely to occur in the resist pattern. Also, because light does not easily reach the bottom, it is difficult to maintain sensitivity during exposure, and it is difficult to form a resist pattern with a good shape. In the resist composition of this embodiment, by including component (Z), it is possible to form a thick resist pattern that is less prone to cracking and has good coverage on the substrate, while maintaining lithography characteristics such as resolution and DOF. This is presumed to be because the presence of component (Z), which has phenolic hydroxyl groups, in the resist film formed using the resist composition causes crosslinking between components (A1) via the constituent unit (a10) in component (A1) upon exposure. This reduces the solubility of the exposed resist film in alkaline developer, thereby making the exposed resist film, which tends to be rigid, more flexible and thus reducing crack occurrence. Furthermore, since there are five or fewer phenyl groups in component (Z), it is presumed that crack occurrence can be reduced while maintaining lithography characteristics such as resolution and DOF.

[0237] (Method for forming resist patterns) A resist pattern formation method according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, exposing the resist film, and developing the exposed resist film to form a resist pattern. One embodiment of such a resist pattern formation method is, for example, a resist pattern formation method carried out as follows.

[0238] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus, either through exposure via a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with an electron beam without going through a mask pattern. After this, a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C. Next, the resist film is subjected to a developing process. In the case of an alkaline developing process, an alkaline developer is used, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used.

[0239] After the developing process, a rinsing process is preferably performed. In the case of an alkaline developing process, a water rinse using pure water is preferred, and in the case of a solvent developing process, a rinsing solution containing an organic solvent is preferred. In the case of a solvent development process, after the development or rinsing process, a process may be performed to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After development or rinsing, the film is dried. In some cases, a bake (post-bake) process may be performed after the development process. In this way, a resist pattern can be formed.

[0240] The support material is not particularly limited and can be any conventionally known material, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As for the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used.

[0241] The resist pattern formation method of this embodiment is useful when forming a thick resist film. Even if the thickness of the resist film formed by coating the resist composition onto the substrate is, for example, 2 to 20 μm, a resist pattern can be stably formed in a good shape.

[0242] The wavelength used for exposure is not particularly limited, and the process can be carried out using radiation such as ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition is highly useful for KrF excimer lasers, ArF excimer lasers, EB, or EUV, and is even more useful for ultraviolet light such as g-rays and i-rays, KrF excimer laser light, and ArF excimer laser light, and is particularly useful for ultraviolet light such as g-rays and i-rays, and KrF excimer laser light. In other words, the resist pattern formation method of this embodiment is particularly useful when the step of exposing the resist film involves irradiating the resist film with ultraviolet light such as g-rays and i-rays, or KrF excimer laser light.

[0243] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is first filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film being exposed is preferred. Examples include water, fluorinated inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Water is preferably used as the immersion medium.

[0244] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution.

[0245] The development process can be carried out by known development methods, such as immersing the support in a developer solution for a certain period of time (dip method), piling the developer solution onto the surface of the support using surface tension and leaving it still for a certain period of time (paddle method), spraying the developer solution onto the surface of the support (spray method), or continuously dispensing the developer solution onto a support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed (dynamic dispensing method).

[0246] The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants are the same as those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total volume of the rinse solution.

[0247] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying the rinsing solution onto a support rotating at a constant speed (rotary coating method), immersing the support in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the surface of the support (spray method).

[0248] According to the resist pattern formation method of this embodiment described above, since the above-mentioned resist composition is used, it is possible to form a thick film resist pattern that is less prone to cracking and has good coverage on the substrate, while maintaining lithography characteristics such as resolution and DOF.

[0249] The resist compositions of the embodiments described above, and the various materials used in the pattern forming methods of the embodiments described above (for example, resist solvents, developers, rinse solutions, anti-reflective film forming compositions, topcoat forming compositions, etc.) are preferably free from impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of metal atom-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The impurity content in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device). [Examples]

[0250] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0251] <Preparation of the resist composition> (Examples 1-26, Comparative Examples 1-6) Each of the components shown in Tables 1-4 was mixed and dissolved to prepare the resist compositions for each example.

[0252] [Table 1]

[0253] [Table 2]

[0254] [Table 3]

[0255] [Table 4]

[0256] In Tables 1-4, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients. (A)-1: A polymer compound represented by the following chemical formula (A-1). This polymer compound (A-1) was obtained by anionic polymerization using monomers that derive the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-1), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2500, and the molecular weight dispersion (Mw / Mn) is 1.20. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 85 / 15.

[0257] [ka]

[0258] (A)-2: A polymer compound (homopolymer) represented by the following chemical formula (A-2). This polymer compound (A-2) was obtained by anionic polymerization of a monomer (hydroxystyrene) that derives the constituent units of the polymer compound. For this polymer compound (A-2), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2500, and the molecular weight dispersion (Mw / Mn) is 1.20.

[0259] [ka] (A)-3: A polymer compound represented by the following chemical formula (A-3). This polymer compound (A-3) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-3), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2500, and the molecular weight dispersion (Mw / Mn) is 1.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 85 / 15.

[0260] [ka]

[0261] (A)-4: A polymer compound represented by the following chemical formula (A-4). This polymer compound (A-4) was obtained by radical polymerization using monomers that derive the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-4), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2500, and the molecular weight dispersion (Mw / Mn) is 1.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 85 / 15.

[0262] [ka]

[0263] (A)-5: A polymer compound represented by the following chemical formula (A-5). This polymer compound (A-5) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-5), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2500, and the molecular weight dispersion (Mw / Mn) is 1.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 85 / 15.

[0264] [ka]

[0265] (B)-1 to (B)-4: Acid generators consisting of compounds represented by the following chemical formulas (B-1) to (B-4).

[0266] [ka]

[0267] (C)-1~(C)-2: Crosslinking agents consisting of compounds represented by the following chemical formulas (C-1)~(C-2), respectively. (D)-1: A nitrogen-containing organic compound consisting of the compound represented by the following chemical formula (D-1).

[0268] [ka]

[0269] (Z)-1 to (Z)-4: Compounds represented by the following chemical formulas (Z-1) to (Z-4). (Z)-11: A compound represented by the following chemical formula (Z)-11.

[0270] [ka]

[0271] (S)-1: Propylene glycol monomethyl ether acetate. (S)-2: Propylene glycol monomethyl ether

[0272] <Formation of resist pattern (1)> Process (i): Each resist composition was applied to a silicon wafer treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds using a spinner. A post-applied bake (PAB) treatment was performed on a hot plate at 90°C for 60 seconds, followed by drying to form resist films with the thicknesses shown in Tables 5-8.

[0273] Step (ii): Next, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through a mask pattern (binary mask) using a KrF exposure system NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). Next, a post-exposure heating (PEB) treatment was performed at 110°C for 60 seconds.

[0274] Step (iii): Next, alkaline development was performed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as the developer, at 23°C for 60 seconds. Afterward, a post-bake was performed at 100°C for 60 seconds. As a result, an isolated space pattern (IS pattern) with a space width of 500 nm was formed.

[0275] [Sensitivity evaluation] In the above <Formation of Resist Pattern (1)>, the optimal exposure amount Eop(mJ / cm) for forming an IS pattern with a space width of 500 nm is used. 2 We calculated the sensitivity (mJ / cm²). 2 )" is shown in Tables 5-8.

[0276] [Resolution evaluation] When forming an IS pattern by gradually increasing the exposure dose from the optimal exposure dose Eop for forming an IS pattern of the target size as described in <Formation of Resist Pattern (1)> above, the minimum size of the pattern that resolves without collapsing was determined using a scanning electron microscope S-9380 (Hitachi High-Technologies Corporation). This is shown in Tables 5-8 as "resolution (nm)".

[0277] [Evaluation of Depth of Focus (DOF)] In the above <Formation of Resist Pattern (1)>, the optimal exposure amount (Eop(mJ / cm)) for forming the IS pattern is described. 2 Then, by appropriately shifting the focus up and down, an IS pattern was formed in the same manner as in <Formation of Resist Pattern (1)> above. At this time, the depth of field (DOF, unit: nm) in which the IS pattern could be formed within a dimensional change rate of ±10% of the target dimension was determined. The results are shown in Tables 5 to 8 as "10% DOF (nm)".

[0278] <Formation of resist pattern (2)> Process (i): Each example of the resist composition was applied using a spinner to an SiO2 substrate having a step with a depth (D in Figure 1 or Figure 2) of 6 μm and a width (W in Figure 1 or Figure 2) of 2.5 μm, which had been treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds. A post-applied bake (PAB) treatment was performed on a hot plate at 90°C for 60 seconds, and the substrate was dried to form a resist film with the thickness shown in Tables 5 to 8.

[0279] Step (ii): Next, the resist film was fully exposed to a KrF excimer laser (248 nm) using a KrF exposure system NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). Next, a post-exposure heating (PEB) treatment was performed at 110°C for 60 seconds.

[0280] Step (iii): Next, alkaline development was performed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as the developer, at 23°C for 60 seconds. Afterward, a post-bake was performed at 100°C for 60 seconds. As a result, a substrate with a simulated resist pattern formed on its surface was obtained.

[0281] [Crack evaluation] The substrate obtained in <Formation of resist pattern (2)> above was observed with an optical microscope, and the number of cracks was counted. The number of cracks was evaluated based on the following evaluation criteria. The results are shown as "cracks" in Tables 5 to 8. Evaluation Criteria ◎: 0 cracks ○: 1 to 9 cracks ×: More than 10 cracks

[0282] [Evaluation of coverage] The substrate obtained in <Formation of resist pattern (2)> above was observed using a scanning electron microscope SU5000 (manufactured by Hitachi High-Technologies Corporation), and its coverage was evaluated based on the following evaluation criteria. The results are shown in Tables 5 to 8 as "Coverage". Evaluation Criteria ○: As shown in Figure 1, the entire substrate is covered with a simulated resist pattern. ×: As shown in Figure 2, there are areas on the substrate's stepped surface that are not covered by the simulated resist pattern.

[0283] [Table 5]

[0284] [Table 6]

[0285] [Table 7]

[0286] [Table 8]

[0287] The results shown in Tables 5-8 confirm that the thick-film resist patterns formed using the resist compositions of Examples 1-26 exhibited good resolution and 10% DOF, reduced crack occurrence, and good coverage. [Explanation of Symbols]

[0288] 1 circuit board 2 steps 3 Resist

Claims

1. A polymer compound (A1) having a constituent unit (a10) represented by the following general formula (a10-1), a constituent unit (a11) derived from a compound represented by the following general formula (a11-1), a constituent unit (a12) represented by the following general formula (a12-1), or a constituent unit derived from a hydroxyalkyl (meth)acrylate, An onium salt-based acid generator (B1) containing an acid generator (B1-1) represented by the following general formula (b1-1), A crosslinking agent (C) selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluryl-based crosslinking agents, and epoxy-based crosslinking agents, Polynuclear phenolic low molecular weight compounds (Z) having five or fewer phenyl groups and It contains, The content of the polynuclear low molecular weight phenol compound (Z) is 0.1 to 35 parts by mass per 100 parts by mass of the high molecular weight compound (A1). A resist composition having a solid content concentration of 15% by mass or more. 【Chemistry 1】 [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ya ｘ１ Wa is a single bond or a divalent linking group. ｘ１ n is an aromatic hydrocarbon group which may have substituents. ａｘ１ [ is an integer greater than or equal to 1.] 【Chemistry 2】 [In formula (a11-1), Ra x2 is a polymerizable group-containing group. Wa x2 is an aromatic hydrocarbon group with (n ax2 + 1) valency. However, a fused ring structure may be formed between Ra x2 and Wa x2. Ra x02 is a substituent that substitutes for a hydrogen atom constituting Wa x2 (aromatic hydrocarbon group). n ax2 is an integer from 0 to 3. If n ax2 is 2 or more, multiple Ra x02 groups may bond to each other to form a ring structure.] 【Transformation 3】 [In the formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Ra 12 is an alkyl group.] 【Chemistry 4】 [In the formula, Rb 201 represents an optionally substituted aryl group. R 202 and R 203 are bonded to each other to form a ring with the sulfur atom in the formula. X- is a counter anion.]

2. The resist composition according to claim 1, wherein the polynuclear phenolic low molecular weight compound (Z) has 2 to 5 phenyl groups.

3. The resist composition according to claim 1 or 2, wherein the polynuclear phenol low molecular weight compound (Z) contains a compound represented by the following general formula (z-1). 【Transformation 5】 [In the formula, Rz １ and Rz ２ n1 and n2 are each independent substituents. n1 and n2 are each independent integers from 0 to 4. Lz １ Rz is a single bond or a divalent linking group. ０ Rz is a hydrocarbon group which may have substituents. ４ [This is a hydrogen atom or an alkyl group.]

4. The resist composition according to any one of claims 1 to 3, wherein the polynuclear low molecular weight phenol compound (Z) contains a compound represented by the following general formula (z-1-1). 【Transformation 6】 [wherein, Rz １ , Rz ２ and Rz ３ are each independently a substituent. n1, n2 and n3 are each independently an integer of 0 to 4. Lz １ is a single bond or a divalent linking group. Rz ４ is a hydrogen atom or an alkyl group.] i. X － This is an anti-anion.

5. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using a resist composition according to any one of claims 1 to 4; exposing the resist film; and developing the exposed resist film to form a resist pattern.

Images