Resist composition, method for forming a resist pattern, and salt

Abstract

To provide a resist composition exhibiting superior stability over time, capable of forming a resist pattern that balances exposure latitude with high sensitivity to an exposure light source, to provide a resist pattern formation method and to provide a compound.SOLUTION: The present invention relates to a resist composition that generates an acid by exposure to light and exhibits a change in solubility to a liquid developer through the action of the acid. The resist composition contains a base material component (A) that exhibits a change in solubility to the liquid developer through the action of an acid, and an acid generating agent component (B) that generates an acid by exposure to light. The acid generating agent component (B) includes a compound represented by general formula (b1-1) described in the specifications.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In lithography, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a development process is performed to form a resist pattern of a predetermined shape in the resist film. A resist material that changes the exposed portion of the resist film so that it dissolves in a developer is called a positive-type resist, and a resist material that changes the exposed portion so that it does not dissolve in a developer is called a negative-type resist.

[0003] In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid progress in miniaturization of patterns. A common method of miniaturization is to shorten the wavelength (increase the energy) of the exposure light source. Specifically, ultraviolet rays such as g-line and i-line have traditionally been used, but mass production of semiconductor elements using KrF excimer lasers and ArF excimer lasers has now begun. Furthermore, research is also being conducted on EUV (extreme ultraviolet), EB (electron beam), X-rays, and other light sources with shorter wavelengths (higher energy) than these excimer lasers.

[0004] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with minute dimensions. To satisfy these requirements, a chemically amplified resist composition has been used, which contains an acid generator component that generates acid upon exposure and a base component whose solubility in a developer changes due to the action of acid.

[0005] A wide variety of acid generator components have been proposed to date, including, for example, onium salt-based acid generators, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. In order to achieve excellent solubility in a developer, good lithography properties, and a resist pattern shape, acid generating components have been investigated. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-85878 Summary of the Invention [Problem to be solved by the invention]

[0007] As lithography technology continues to advance and resist patterns become increasingly finer, resist compositions are required to have high exposure latitude, high sensitivity to the exposure light source, and stability over time. However, in the prior art, it was not possible to sufficiently achieve both of these characteristics, and it was not possible to resolve the trade-off between the characteristics.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a resist composition that is capable of forming a resist pattern that has excellent stability over time and that combines high exposure latitude and high sensitivity to an exposure light source, a method of forming a resist pattern that uses the resist composition, and a salt that is useful for the resist composition. [Means for solving the problem]

[0009]

[0009] As a result of intensive research conducted by the present inventors in order to solve the above-mentioned problems, they found that the following configuration makes it possible to obtain a resist composition that is capable of forming a resist pattern that exhibits excellent stability over time, and that also exhibits high exposure latitude and high sensitivity to an exposure light source, a method of forming a resist pattern that uses the resist composition, and a salt that is useful for the resist composition, and they have thus completed the present invention.

[0010] That is, the present invention is as follows.

[0011] The resist composition according to an embodiment of the present invention comprises: A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, The composition contains a base component (A) whose solubility in a developer changes under the action of an acid, and an acid generator component (B) that generates an acid upon exposure to light, The acid generator component (B) is a resist composition containing a compound represented by the following general formula (b1-1).

[0012] [ka]

[0013] [In general formula (b1-1), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M m+ represents an m-valent organic cation.

[0014] [ka]

[0015] [In formula (bz-1), each R1 independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent an integer of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.]

[0016] A method for forming a resist pattern according to another embodiment of the present invention is a method for forming a resist pattern, including the steps of forming a resist film on a support using a resist composition according to an embodiment of the present invention, exposing the resist film to light, and developing the resist film to form a resist pattern.

[0017] A salt according to another embodiment of the present invention is represented by the following general formula (b1-1).

[0018] [ka]

[0019] [In general formula (b1-1), Rf 01 and Rf 02each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M m+ represents an m-valent organic cation.

[0020] [ka]

[0021] [In formula (bz-1), each R1 independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent an integer of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.] [Effects of the Invention]

[0022] The present invention is capable of providing a resist composition that is capable of forming a resist pattern that exhibits excellent stability over time and that combines high exposure latitude with high sensitivity to an exposure light source, a method of forming a resist pattern that uses the resist composition, and a compound that is useful for the resist composition. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes in detail the preferred embodiments of the present invention, but the present invention is not limited to the following preferred embodiments.

[0024] In this specification and claims, the term "aliphatic" is defined as a relative concept to aromatic, and refers to groups, compounds, etc. that do not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with halogen atoms, and examples of such halogen atoms include fluorine, chlorine, bromine, and iodine atoms. The term "fluorinated alkyl group" or "fluorinated alkylene group" refers to an alkyl group or alkylene group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "optionally substituted" includes both cases where a hydrogen atom (-H) is replaced with a monovalent group and cases where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is a general concept that includes irradiation with radiation.

[0025] The term "structural unit derived from an acrylate ester" refers to a structural unit formed by cleavage of the ethylenic double bond of an acrylate ester. An "acrylic acid ester" is a compound in which the hydrogen atom at the terminal carboxyl group of acrylic acid (CH2=CH-COOH) is substituted with an organic group. In the acrylic acid ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. α0 ) is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. α0 ) is substituted with a substituent containing an ester bond, or α0 This also includes α-hydroxyacrylic esters in which the hydroxyl group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom has been substituted with a substituent may be referred to as an α-substituted acrylic ester. Furthermore, acrylic esters and α-substituted acrylic esters may be collectively referred to as "(α-substituted) acrylic esters."

[0026] The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specific examples thereof include alkyl groups having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc.). Specific examples of the halogenated alkyl group as a substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as a substituent at the α-position" have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being particularly preferred. Specific examples of the hydroxyalkyl group as the substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" have been substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0027] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the corresponding substances present in the composition, unless otherwise specified. Furthermore, chemical structural formulas in this disclosure may be written as simplified structural formulas in which hydrogen atoms are omitted. In this specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereomers. In such cases, a single chemical formula represents all isomers. These isomers may be used alone or as a mixture. In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0028] [Resist Composition] A resist composition according to an embodiment of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, The composition contains a base component (A) whose solubility in a developer changes under the action of an acid, and an acid generator component (B) that generates an acid upon exposure to light, The acid generator component (B) is a resist composition containing a compound represented by the following general formula (b1-1).

[0029] [ka]

[0030] [In general formula (b1-1), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M m+ represents an m-valent organic cation.

[0031] [ka]

[0032] [In formula (bz-1), each R1 independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent an integer of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.]

[0033] When a resist film is formed using a resist composition according to an embodiment of the present invention and the resist film is subjected to selective exposure, acid is generated in the exposed areas of the resist film, and the solubility of component (A) in a developer changes due to the action of the acid, whereas the solubility of component (A) in a developer does not change in the unexposed areas of the resist film, resulting in a difference in solubility in a developer between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive, the exposed areas of the resist film are dissolved and removed, forming a positive resist pattern, whereas if the resist composition is negative, the unexposed areas of the resist film are dissolved and removed, forming a negative resist pattern.

[0034] In this specification, a resist composition that forms a positive resist pattern by dissolving and removing exposed portions of a resist film is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern by dissolving and removing unexposed portions of a resist film is referred to as a negative resist composition. The resist composition according to an embodiment of the present invention may be a positive resist composition or a negative resist composition. Furthermore, the resist composition according to an embodiment of the present invention may be for an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment.

[0035] A resist composition according to an embodiment of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, and contains a base component (A) whose solubility in a developer changes due to the action of the acid, and an acid generator component (B) that generates an acid upon exposure.

[0036] Examples of the component (A) whose solubility in a developer changes under the action of an acid include known compounds. The component (A) may generate an acid upon exposure. In this case, the component (A) is a "base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid." When the component (A) is a base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the component (A1) described below is preferably a polymeric compound that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid. As such a polymeric compound, a copolymer having a structural unit that generates an acid upon exposure can be used.

[0037] In the resist composition according to an embodiment of the present invention, the solubility of the base component (A) in a developer changes due to the action of an acid, and therefore in an alkaline development process, the solubility of the resist film in an alkaline developer increases during development. Furthermore, the resist composition according to an embodiment of the present invention contains an acid generator component (B) that generates an acid upon exposure, and the acid generator component (B) contains a compound (b1-1) represented by the following general formula (b1-1):

[0038] [ka]

[0039] [In general formula (b1-1), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M m+ represents an m-valent organic cation.

[0040] [ka]

[0041] [In formula (bz-1), each R1 independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent an integer of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.]

[0042] Compound (b1-1) exhibits excellent sensitivity due to the total number of atoms in the main chain of X being 4 or more. This is presumably because the protecting group and the sulfonic acid moiety can be brought into sufficient proximity, improving reactivity. Furthermore, because X is a divalent linking group with a specific structure, it also exhibits excellent stability over time. This is presumably because the chain structure represented by X does not contain an acetal bond or a carbonate ester bond, preventing decomposition over time. Furthermore, compound (b1-1) has the effect of appropriately suppressing acid diffusion because a polycyclic hydrocarbon group represented by Y and a monocyclic group represented by Z are bonded in one molecule by an ester bond represented by L or a divalent linking group containing an oxygen atom. As a result, the resist composition according to this embodiment of the present invention exhibits excellent stability over time and is capable of forming a resist pattern that combines high exposure latitude and high sensitivity to an exposure light source.

[0043] Here, the acetal bond in the present application refers to a bond represented by -OCO- in R1-OCO-R2 (R1, R2: alkyl group, fluoroalkyl group, or carbonyl group).

[0044] Component (A) In the resist composition according to this embodiment of the present invention, the component (A) is a base component whose solubility in a developer changes due to the action of an acid. The component (A) may be one whose solubility in a developer increases or decreases under the action of an acid. By using the component (A), the polarity of the base component changes before and after exposure, and therefore good development contrast can be obtained not only in an alkaline development process but also in a solvent development process.

[0045] The component (A) is more preferably one that contains a polymeric compound (A1) (hereinafter also referred to as "component (A1)") that has a structural unit (a1) that contains an acid-decomposable group whose polarity increases when acted upon by an acid. As the component (A1), it is preferable to use a polymeric compound that has, in addition to the structural unit (a1), a structural unit (a2) that includes a lactone-containing cyclic group, an —SO 2 —-containing cyclic group, or a carbonate-containing cyclic group.

[0046] When an alkaline development process is applied, the base component containing the component (A1) is poorly soluble in an alkaline developer before exposure, but when an acid is generated from the component (B) upon exposure, the acid increases the polarity and the solubility in the alkaline developer. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition to a support is selectively exposed to light, the exposed areas of the resist film change from poorly soluble in an alkaline developer to soluble, while the unexposed areas of the resist film remain poorly soluble in alkali, and therefore a positive resist pattern is formed by alkaline development.

[0047] On the other hand, when a solvent development process is applied, the base component (A) containing the component (A1) is highly soluble in organic developers before exposure, but when an acid is generated from the component (B) upon exposure, the acid increases the polarity and reduces the solubility in organic developers. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition to a support is selectively exposed to light, the exposed areas of the resist film change from soluble to sparingly soluble in organic developers, while the unexposed areas of the resist film remain soluble. Therefore, by developing with an organic developer, a contrast can be created between the exposed and unexposed areas, and a negative resist pattern can be formed.

[0048] In the resist composition according to an embodiment of the present invention, the component (A) may use either a single type of compound, or a combination of two or more types of compounds.

[0049] <Constituent unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases upon the action of an acid. The term "acid-decomposable group" refers to a group having acid decomposability in which at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that decompose under the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxy group, an amino group, a sulfo group (-SO3H), etc. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as an "OH-containing polar group") is preferred, a carboxy group or a hydroxy group is more preferred, and a carboxy group is particularly preferred. More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group). Here, the term "acid-dissociable group" refers to either (i) a group having acid dissociability such that the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a portion of the bond is cleaved by the action of an acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. Therefore, when the acid-dissociable group dissociates due to the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, increasing the polarity. As a result, the polarity of the entire component (A1) increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer and decreasing the solubility when the developer is an organic developer.

[0050] The structural unit (a1) preferably contains an acid-decomposable group having an alicyclic hydrocarbon group, and more preferably contains an acid-decomposable group having a monocyclic alicyclic hydrocarbon group. The acid-decomposable group (acid-dissociable group) in the structural unit (a1) has an appropriate bulkiness, which makes it possible to appropriately control the acid diffusion and adjust the solubility in the developer, thereby reducing roughness when forming a resist pattern. Examples of the acid-dissociable group within the structural unit (a1) include those groups that have been proposed as acid-dissociable groups for base resins used in chemically amplified resists. Specific examples of acid-dissociable groups that have been proposed for use in base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups."

[0051] Tertiary alkyl ester-type acid-labile group: Among the polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for convenience.

[0052] [ka]

[0053] [In the formula, Ra' 4 ~Ra' 6 Each represents a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0054] Ra' 4 Examples of the hydrocarbon group represented by include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0055] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0056] Ra' 4 represents a cyclic hydrocarbon group (an aliphatic hydrocarbon group that is a monocyclic group, an aliphatic hydrocarbon group that is a polycyclic group, or an aromatic hydrocarbon group), the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, or may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0057] Ra' 4 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, 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 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. 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 substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Ra' 4Specific examples of the aromatic hydrocarbon group in the formula (I) include a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle; a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0058] Ra' 4 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter these substituents are collectively referred to as "Ra x5 ") are also examples. where R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents, or may have one or more of each of multiple types of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0059] Ra' 4 The chain or cyclic alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group of Ra' 4 The same can be mentioned.

[0060] Ra' 5 and Ra' 6 and (a1-r-2) are bonded to each other to form a ring, suitable examples of the acid-dissociable group represented by the above formula (a1-r-2) include a group represented by the following formula (a1-r2-1), a group represented by the following formula (a1-r2-2), and a group represented by the following formula (a1-r2-3): On the other hand, Ra' 4 ~Ra'6 When the groups are not bonded to each other but are independent hydrocarbon groups, suitable examples of the acid-dissociable group represented by the above formula (a1-r-2) include groups represented by the following formula (a1-r2-4):

[0061] [ka]

[0062] [In formula (a1-r2-1), Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom. 0 Yab 0 and represents a group which together with the above represents a group which forms an alicyclic hydrocarbon group, and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra 101 ~Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 104 is an aromatic hydrocarbon group which may have a substituent. In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond.]

[0063] In the above formula (a1-r2-1), Ra 031 is preferably a chain alkyl group, and is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, part of which may be substituted with a halogen atom or a heteroatom-containing group.

[0064] Ra 031 The linear alkyl group in the formula (I) has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra 031 In the formula (I), the branched alkyl group is the above-mentioned Ra' 4 The same can be mentioned.

[0065] Ra 031 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0066] In formula (a1-r2-1), Xab 0 (Yab 0 The group forming an alicyclic hydrocarbon group together with Ra' in the above formula (a1-r-2) is 4The groups listed as aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) are preferred, which are monocyclic or polycyclic groups. Among them, alicyclic hydrocarbon groups are preferred, monocyclic alicyclic hydrocarbon groups are more preferred, and groups in which two or more hydrogen atoms have been removed from a monocycloalkane are more preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, cycloheptane, and cyclooctane.

[0067] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the above formula (a1-r-2). 4 Examples of such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) shown above. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. The substituent may be any of the above-mentioned Ra' 4 Examples of the substituents include the same as those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 In the above formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 101 ~Ra 103 In the formula (I), examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and adamantyl group. Ra 101 ~Ra 103Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferred, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, with a hydrogen atom being particularly preferred.

[0068] The above Ra 101 ~Ra 103 Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula: x5 The same groups as those shown below can be mentioned.

[0069] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0070] In the formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is the same as Ra' in the above formula (a1-r-2). 4 The groups mentioned above as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in the formula include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. 104 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0071] Ra in formula (a1-r2-3)104 Examples of the substituent that may be possessed by include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0072] In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13 In the above, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above Ra 101 ~Ra 103 Examples include the same monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms as in the chain saturated hydrocarbon group in the above formula (1). Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. The above Ra' 12 and Ra' 13 When the chain saturated hydrocarbon group represented by the formula: is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

[0073] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group which may have a substituent. 14 The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0074] Ra' 14The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0075] Ra' 14 The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferred.

[0076] Ra' 14 When 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. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0077] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon groups Ra' are the same as those in 14is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 Examples of the substituent that may be possessed by Ra include 104 Examples of the substituents include the same as those that may be possessed by the group.

[0078] Ra' in formula (a1-r2-4) 14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14 When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any one of the 1st, 2nd, or 9th position of the anthryl group.

[0079] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0088] [ka]

[0089] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0090] [ka]

[0091] As the acid-dissociable group, among the groups represented by the above general formulae (a1-r2-1) to (a1-r2-4), the group represented by the above general formula (a1-r2-1) is preferred. That is, the base component (A) according to an embodiment of the present invention preferably contains a polymeric compound (A1) having a structural unit containing an acid-dissociable group represented by the above formula (a1-r2-1).

[0092] Specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1).

[0093] (Structural unit (a1) represented by general formula (a1-1)) In the resist composition according to an embodiment of the present invention, the base component (A) preferably contains a polymeric compound (A1) having a structural unit (a1) represented by the following general formula (a1-1).

[0094] [ka]

[0095] (In general formula (a1-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 3 represents a divalent linking group. na3 represents an integer of 0 to 2. Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom. Xab 0 Yab 0 represents a group which, together with Some or all of the hydrogen atoms in this alicyclic hydrocarbon group may be substituted.

[0096] In general formula (a1-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0097] In general formula (a1-1), Va 3 represents a divalent linking group. Examples of the divalent linking group include a divalent hydrocarbon group which may have an ether bond. 3 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0098] Va 3 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0099] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. 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. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as 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-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0100] Examples of the aliphatic hydrocarbon group containing a ring in its structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as the straight-chain aliphatic hydrocarbon group or the branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms.

[0101] The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0102] Va 3 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such aromatic hydrocarbon groups preferably have 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents.

[0103] Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0104] Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0105] In general formula (a1-1), na3 represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0106] In formula (a1-r2-1) and formula (a1-1), Ra 031 is as mentioned above.

[0107] In formula (a1-r2-1) and general formula (a1-1), Ra 031 Among the above, is preferably a chain alkyl group, more preferably a monovalent chain alkyl group having 1 to 3 carbon atoms, and more specifically, a methyl group, an ethyl group, a propyl group, or an isopropyl group.

[0108] In formula (a1-r2-1) and general formula (a1-1), Yab 0 represents a carbon atom. In formula (a1-r2-1) and general formula (a1-1), Xab 0 Yab 0 and represents a group which together with the above represents a group which forms an alicyclic hydrocarbon group, and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted.

[0109] Specific examples of the structural unit (a1) are listed below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] Among the above examples, the structural unit (a1) is preferably at least one selected from the group consisting of structural units represented by chemical formulas (a01-1a-01) to (a01-1a-18), and more preferably at least one selected from the group consisting of structural units represented by chemical formulas (a01-1a-01) to (a01-1a-3), (a01-1a-5), (a01-1a-9), and (a01-1a-16).

[0114] The structural unit (a1) that the component (A1) may have may be of one type, or may be of two or more types. Within the component (A1), the proportion of the structural unit (a1) relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 20 to 80 mol %, more preferably 30 to 70 mol %, and even more preferably 40 to 60 mol %. By ensuring that the proportion of the structural unit (a1) is at least as large as the lower limit of the above-mentioned preferred range, lithography properties such as high sensitivity, resolution, and improved roughness can be achieved. By ensuring that the proportion is at most the upper limit, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0115] (Structural unit (a2)) The component (A1) may further include a structural unit (a2) (excluding those corresponding to the structural unit (a1)) that includes a lactone-containing cyclic group, an —SO2-containing cyclic group, or a carbonate-containing cyclic group. The lactone-containing cyclic group, -SO2-containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. Furthermore, the presence of the structural unit (a2) results in favorable lithography properties, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0116] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group. When there is additional ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0117] [ka]

[0118] [In general formulas (a2-r-1) to (a2-r-7), Ra' 21 are each 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, a carbonate-containing cyclic group, or an -SO2- containing cyclic group; A" 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; n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond.]

[0119] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the alkoxy group in the formula (1) is preferably linear or branched. 21 Examples of the alkyl group include a group in which the alkyl groups mentioned above are linked to an oxygen atom (—O—). Ra' 21 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Ra' 21 The halogenated alkyl group in the formula Ra' is 21 Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0120] Ra' 21 In the -COOR" and -OC(=O)R" groups, R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO2- containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.

[0121] When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.

[0122] Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. The carbonate-containing cyclic group in R″ is the same as the carbonate-containing cyclic group described below, and specific examples include groups represented by the general formulae (ax3-r-1) to (ax3-r-3). The -SO2-containing cyclic group in R'' is the same as the -SO2-containing cyclic group described below, and specific examples include groups represented by general formulae (a5-r-1) to (a5-r-4).

[0123] Ra' 21 The hydroxyalkyl group in the formula (I) preferably has 1 to 6 carbon atoms, and specifically, the hydroxyalkyl group in the formula (I) is preferably the hydroxyalkyl group in the formula (I) 21 and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0124] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a straight-chain or branched-chain alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. A" 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.

[0125] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are listed below.

[0126] [ka]

[0127] [ka]

[0128] The term "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring skeleton, specifically a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring containing -SO2- in the ring skeleton is counted as the first ring, and if it contains only that ring, it is called a monocyclic group. If it contains other ring structures, it is called a polycyclic group regardless of the structure. The -SO2- containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, i.e., a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms part of the ring skeleton. More specific examples of the —SO2—-containing cyclic group include groups represented by the following general formulae (a5-r-1) to (a5-r-4).

[0129] [ka]

[0130] [In general formulas (a5-r-1) to (a5-r-4), Ra' 51 are each 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, a carbonate-containing cyclic group, or an -SO2- containing cyclic group; A" 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 of 0 to 2.

[0131] In the general formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3), and (a2-r-5). Ra' 51 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above include those mentioned in the explanation of the above. Specific examples of the groups represented by general formulae (a5-r-1) to (a5-r-4) are listed below, in which "Ac" represents an acetyl group.

[0132] [ka]

[0133] [ka]

[0134] [ka]

[0135] The term "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -OC(=O)-O- in its ring skeleton. The carbonate ring is counted as the first ring, and when there is only a carbonate ring, it is called a monocyclic group. When there is further ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. The carbonate ring-containing cyclic group is not particularly limited and any one can be used. Specific examples include groups represented by the following general formulae (ax3-r-1) to (ax3-r-3).

[0136] [ka]

[0137] [In the formula, Ra' x31 are each 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, a carbonate-containing cyclic group, or an -SO2- containing cyclic group; A" 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; p' is an integer of 0 to 3, and q' is 0 or 1. * represents a bond.]

[0138] In the general formulae (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' X31 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra'21 Examples of the above include those mentioned in the explanation of the above. Specific examples of the groups represented by the general formulae (ax3-r-1) to (ax3-r-3) are listed below.

[0139] [ka]

[0140] Of the structural units (a2), structural units derived from acrylate esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent are particularly preferred. Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0141] [ka]

[0142] [In the general formula (a2-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] 21 is a single bond or a divalent linking group. 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Ra 21 is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an SO2-containing cyclic group.

[0143] In the formula (a2-1), R is the same as R in the formula (a1-1). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0144] In the formula (a2-1), Ya 21The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0145] Optionally substituted divalent hydrocarbon group: Ya 21 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0146] Ya 21 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0147] 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, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. 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. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as 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-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0148] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, such as a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, or a carbonyl group.

[0149] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include 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. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0150] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group 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. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0151] Ya 21 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 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this carbon number does not include the number of carbon atoms in the substituent. 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 substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0152] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group 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 alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0153] Divalent linking groups containing heteroatoms: Ya 21 is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and groups represented by the 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 -, wherein Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3.

[0154] When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Formula-Y 21 -OY22 -, -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 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the above-mentioned Ya 21 Examples of the divalent linking group include the same groups as those (divalent hydrocarbon groups which may have a substituent) mentioned in the description of the divalent linking group in the above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred.

[0155] Y 22 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 group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, in the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by - is a group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0156] Among the above, Ya 21 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.

[0157] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group, an —SO 2 —-containing cyclic group, or a carbonate-containing cyclic group. Ra 21 Suitable examples of the lactone-containing cyclic group, the -SO2- containing cyclic group, and the carbonate-containing cyclic group in the formula (a2-r-1), (a2-r-7), (a5-r-1), (a5-r-4), and (ax3-r-1), respectively, are the groups represented by the general formulas (ax3-r-3).

[0158] In the above formula (a2-1), Ra 21 Among the above, is preferably a lactone-containing cyclic group or an -SO2- containing cyclic group, more preferably a group represented by the general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1), and even more preferably a group represented by the general formula (a2-r-1) or (a2-r-2). Specifically, groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), and (r-lc-6-1) are preferred, and groups represented by the chemical formulas (r-lc-1-1), (r-lc-2-1) and (r-lc-2-12) are more preferred.

[0159] The structural unit (a2) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%. When the proportion of the structural unit (a2) is at least as great as the preferred lower limit, the effects achieved by including the structural unit (a2) can be fully obtained due to the effects described above. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0160] Other structural units The component (A1) may also include other structural units in addition to the above-mentioned structural units (a1) and (a2). Examples of other structural units include structural units (a3) ​​containing a polar group-containing aliphatic hydrocarbon group, structural units (a4) containing an acid-decomposable group whose polarity increases when exposed to acid, structural units (a6) containing a hydroxystyrene skeleton, and structural units (a8) containing an acid-non-dissociable aliphatic cyclic group. Except for those corresponding to structural units (a1) and (a2), many of the structural units (a3) ​​to (a8) that are conventionally known as those used in resin components of resist compositions can be used.

[0161] The proportion of the component (A1) within the component (A), relative to the total mass of the component (A), is preferably 25 mass% or more, more preferably 50 mass% or more, even more preferably 75 mass% or more, and may even be 100 mass%. When this proportion is 25 mass% or more, a resist pattern that is excellent in various lithography properties such as high sensitivity, resolution, and roughness is more likely to be formed.

[0162] In the resist composition according to an embodiment of the present invention, the amount of the component (A) may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0163] Acid generator component (component (B)) The resist composition according to an embodiment of the present invention contains, in addition to the component (A) described above, an acid generator component (B) (hereinafter also referred to as “component (B)”) that generates an acid upon exposure. The acid generator component (B) includes an acid generator (B1) (hereinafter also referred to as “component (B1)”) consisting of a compound represented by the following general formula (b1-1):

[0164] [ka]

[0165] [In general formula (b1-1), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M m+ represents an m-valent organic cation.

[0166] [ka]

[0167] [In formula (bz-1), each R1 independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent an integer of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.]

[0168] [Anion part (ZLYXC(Rf 01 )(Rf 02 )-SO3 - )] In general formula (b1-1), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom.

[0169] Rf 01 and Rf 02 The fluorinated alkyl groups represented by the formula (I) may each independently be chain-like or cyclic, and are preferably linear or branched. 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.

[0170] Specific examples include groups in which some or all of the hydrogen atoms constituting a linear alkyl group, such as a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, or decyl group, have been substituted with fluorine atoms; and groups in which some or all of the hydrogen atoms constituting a branched alkyl group, such as a 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, or 3-methylbutyl group, have been substituted with fluorine atoms. Also, Rf01 and Rf 02 The fluorinated alkyl groups represented by each of the formulas may independently contain an atom other than a fluorine atom, a carbon atom or a hydrogen atom, such as an oxygen atom, a sulfur atom or a nitrogen atom. Among them, Rf 01 and Rf 02 The fluorinated alkyl group represented by is preferably a group in which some or all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms, and is preferably a group in which all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms (perfluoroalkyl group).

[0171] In general formula (b1-1), Rf 01 and Rf 02 Preferably, each represents a fluorine atom.

[0172] In general formula (b1-1), X represents a divalent linking group having a main chain with a total of 4 or more atoms, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Ester bonds include -OC(=O)- and -C(=O)-O-.

[0173] As the divalent linking group represented by X and having a total of 4 or more atoms in the main chain, linking groups represented by the following formulae (y-b1-1) to (y-b1-12) are more preferred.

[0174] [ka]

[0175] [In formulas (y-b1-1) to (y-b1-12), V 100 represents an alkylene group or a fluorinated alkylene group having 2 to 5 carbon atoms, and V 101represents a single bond, an alkylene group having 1 to 5 carbon atoms, or a fluorinated alkylene group; V 102 represents an alkylene group or a fluorinated alkylene group having 2 to 30 carbon atoms, and the total number of atoms in the main chain in formulas (y-b1-1) to (y-b1-12) is 4 or more. * represents Rf 01 and Rf 02 represents a bond bonded to the carbon atom to which it is bonded, and ** represents a bond bonded to Y.]

[0176] In the above formulas (y-b1-1) to (y-b1-12), V 100 , V 101 , and V 102 The alkylene group in may be linear or branched.

[0177] V 100 The alkylene group having 2 to 5 carbon atoms in the formula (I) is preferably an alkylene group having 2 to 4 carbon atoms, and more preferably an alkylene group having 2 to 3 carbon atoms. Specific examples include an ethylene group [-CH2CH2-]; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2-; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-].

[0178] V 100 The fluorinated alkylene group having 2 to 5 carbon atoms in the formula (I) is preferably a fluorinated alkylene group having 2 to 4 carbon atoms, and more preferably a fluorinated alkylene group having 2 to 3 carbon atoms.

[0179] V 100 In the formula, the fluorinated alkylene group having 2 to 5 carbon atoms is V 100Examples include alkylene groups having 2 to 5 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms, and preferred are linear fluorinated alkylene groups having 2 to 5 carbon atoms. Specific examples include fluorinated ethylene groups [-HCH2-, -CF2CH2-]; fluorinated alkylethylene groups such as -CH(CF3)CH2-, -CH(CF3)CH(CH3)-, and -C(CF3)2CH2-; fluorinated trimethylene groups (fluorinated n-propylene groups) [-CHFCH2CH2-, -CF2CH2CH2-]; fluorinated alkyltrimethylene groups such as -CH(CF3)CH2CH2- and -CHFCH(CH3)CH2-; fluorinated tetramethylene groups [-CHFCH2CH2CH2-, -CF2CH2CH2CH2-]; fluorinated alkyltetramethylene groups such as -CH(CF3)CH2CH2CH2- and -CHFCH(CH3)CH2CH2-; and fluorinated pentamethylene groups [-CHFCH2CH2CH2CH2-, -CF2CH2CH2CH2-].

[0180] V 101 The alkylene group having 1 to 5 carbon atoms in the formula (I) is preferably an alkylene group having 1 to 4 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Specifically, methylene groups [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; ethylene groups [-CH2CH2-]; alkyl groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2-. Examples include an ethylene group; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-].

[0181] V101 The fluorinated alkylene group having 1 to 5 carbon atoms in the formula (I) is preferably a fluorinated alkylene group having 1 to 4 carbon atoms, more preferably a fluorinated alkylene group having 1 to 3 carbon atoms. Furthermore, a linear fluorinated alkylene group having 1 to 5 carbon atoms is preferred. V 101 In the formula, the fluorinated alkylene group having 1 to 5 carbon atoms is V 101 In particular, the alkylene group having 1 to 5 carbon atoms in 01 and Rf 02 A fluorinated alkylene group in which the carbon atom bonded to the carbon atom to which is bonded is fluorinated is preferred. V 101 Specific examples of the fluorinated alkylene group having 1 to 5 carbon atoms in the formula (I) include a fluorinated methylene group [-CHF-, -CF2-]; a fluorinated alkylmethylene group such as -C(CF3)2-, -C(CF3)(CH2CH3)-, -C(CF3)(CH2CH2CH3)-; a fluorinated ethylene group [-CHFCH2-, -CF2CH2-]; a fluorinated alkylethylene group such as -CH(CF3)CH2-, -CH(CF3)CH(CH3)-, -C(CF3)2CH2-; a fluorinated trimethylene group (a fluorinated n-propylene group) [ fluorinated alkyltrimethylene groups such as -CHFCH2CH2- and -CF2CH2CH2-]; fluorinated alkyltrimethylene groups such as -CH(CF3)CH2CH2- and -CHFCH(CH3)CH2-; fluorinated tetramethylene groups [-CHFCH2CH2CH2- and -CF2CH2CH2CH2-]; fluorinated alkyltetramethylene groups such as -CH(CF3)CH2CH2CH2- and -CHFCH(CH3)CH2CH2-]; and fluorinated pentamethylene groups [-CHFCH2CH2CH2CH2- and -CF2CH2CH2CH2CH2-].

[0182] V 102 The alkylene group having 2 to 30 carbon atoms in V is preferably an alkylene group having 2 to 10 carbon atoms, and more preferably an alkylene group having 2 to 5 carbon atoms. 101 The alkylene groups having 2 to 5 prime numbers listed above are more preferred, and an ethylene group [—CH2CH2—] is even more preferred.

[0183] V 102 The fluorinated alkylene group having 2 to 30 carbon atoms in V is preferably a fluorinated alkylene group having 2 to 10 carbon atoms, and more preferably a fluorinated alkylene group having 2 to 5 carbon atoms. 101 Fluorinated alkylene groups having 2 to 5 prime numbers as listed in (1) are more preferred.

[0184] In general formula (b1-1), X is preferably an alkylene group or a fluorinated alkylene group having a total of 4 or more atoms in the main chain and containing an ester bond. As X, among the linking groups represented by the above formulae (y-b1-1) to (y-b1-12), the linking groups represented by the above formulae (y-b1-7) and (y-b1-9) are more preferable.

[0185] In general formula (b1-1), Y represents a divalent polycyclic hydrocarbon group which may have a substituent. Examples of the polycyclic hydrocarbon group represented by Y include groups in which two hydrogen atoms have been removed from a bicycloalkane, tricycloalkane, tetracycloalkane, or the like having 7 to 30 carbon atoms. Specific examples include groups in which two hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.

[0186] Among these polycyclic groups, a group in which two hydrogen atoms have been removed from adamantane, a group in which two hydrogen atoms have been removed from norbornane, or a group in which two hydrogen atoms have been removed from tetracyclododecane is preferred, and a group in which two hydrogen atoms have been removed from adamantane or a group in which two hydrogen atoms have been removed from norbornane is more preferred. That is, it is preferred that the polycyclic hydrocarbon group represented by Y in general formula (b1-1) has an adamantane skeleton or a norbornane skeleton.

[0187] These polycyclic hydrocarbon groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. The linear or branched alkyl group having 1 to 5 carbon atoms as a substituent is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

[0188] In general formula (b1-1), L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of the ester bonds and oxygen atoms may be bonded independently via alkylene groups. Ester bonds include -OC(=O)- and -C(=O)-O-.

[0189] Preferred examples of the divalent linking group represented by L include -O-, -C(=O)-O-, -C(=O)-, -CH2-C(=O)-O-, -CH2-OC(=O)-, and the like. Among these, from the viewpoint of raw materials, -O-, -C(=O)-O-, -CH2-C(=O)-O-, and -CH2-OC(=O)- are preferred, and -C(=O)-O-, -CH2-C(=O)-O-, and -CH2-OC(=O)- are particularly preferred.

[0190] L is preferably *-OC(=O)-**, *-CH2-C(=O)-O-**, or *-CH2-OC(=O)-**, and more preferably *-OC(=O)-**. * represents a bond bonded to Y, and ** represents a bond bonded to Z.

[0191] In general formula (b1-1), Z represents a substituent represented by the following formula (bz-1).

[0192] [ka]

[0193] [In formula (bz-1), each R1 independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent an integer of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.]

[0194] Examples of the halogen atom in R1 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. The heteroatom in R1 includes an oxygen atom, a sulfur atom, and a nitrogen atom.

[0195] As the linear or branched alkyl group in which a part of the carbon atoms is substituted with a heteroatom, a linear or branched alkoxy group, a linear or branched alkoxyalkyl group, a linear or branched alkylthio group, a linear or branched alkylthioalkyl group, a linear or branched alkylamino group, or a linear or branched alkylaminoalkyl group is preferred, a linear or branched alkoxy group, a linear or branched alkylthio group, or a linear or branched alkylamino group is preferred, and a linear or branched alkoxy group is more preferred. Among the linear or branched alkoxy groups, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.

[0196] The linear alkyl group represented by R1 preferably has 1 to 20 carbon atoms, more preferably 2 to 15, still more preferably 3 to 12, and particularly preferably 3 to 10. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, and a docosyl group.

[0197] The branched alkyl group represented by R1 preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and particularly preferably 3 to 10 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0198] The linear acyl group represented by R1 is preferably a linear acyl group having 1 to 3 carbon atoms, and specific examples include a formyl group, an acetyl group, a propionyl group, and an acryloyl group. The branched acyl group represented by R1 is preferably a branched acyl group having 3 to 10 carbon atoms, and examples thereof include an isobutyryl group and a methacryloyl group.

[0199] Examples of the linear or branched alkyloxycarbonyl group represented by R1 include linear or branched alkoxycarbonyl groups in which a linear or branched alkoxy group having 1 to 4 carbon atoms is bonded to a carbonyl group (specifically, alkyloxycarbonyl groups such as a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, an n-propoxycarbonyl group, etc.; alkenyloxycarbonyl groups such as a vinyloxycarbonyl group, an allyloxycarbonyl group, etc.).

[0200] In formula (bz-1), it is preferable that each R1 independently represents a hydrogen atom or a linear or branched alkyl group in which some of the carbon atoms may be substituted with heteroatoms; it is more preferable that one R1 represents a linear or branched alkyl group in which some of the carbon atoms may be substituted with heteroatoms, and the other R1 represents a hydrogen atom; and it is even more preferable that one R1 represents a linear or branched alkoxy group or a linear or branched alkyl group in which the other R1 represents a hydrogen atom. Among the linear or branched alkoxy groups or linear or branched alkyl groups represented by one of R1, a methoxy group, an ethoxy group, an isopropyl group, or a tert-butyl group is more preferred, and a methoxy group or a tert-butyl group is even more preferred.

[0201] W is an oxygen atom, a sulfur atom, or -NR n - represents R n represents a hydrogen atom or a linear or branched alkyl group. -NR n -R in n Examples of the linear alkyl group represented by include linear alkyl groups having 3 to 10 carbon atoms (specifically, methyl, ethyl, n-propyl, etc.). -NR n -R in n Examples of the branched alkyl group represented by include branched alkyl groups having 1 to 10 carbon atoms (specifically, an isopropyl group, a tert-butyl group, etc.).

[0202] m1 preferably represents an integer of 1 to 3, and more preferably represents 2 or 3. n1 preferably represents an integer of 0 to 1, and more preferably represents 1. In the embodiment of the present invention, it is preferred that n1 represents 0 and m1 represents an integer of 2 or 3 in formula (bz-1).

[0203] In an embodiment of the present invention, the compound represented by general formula (b1-1) is preferably a compound represented by the following general formula (b1-2) or general formula (b1-3).

[0204] [ka]

[0205] [In general formula (b1-2) and general formula (b1-3), k01 and k02 each independently represent an integer of 0 to 2, k01 + k02 represents 1 or 2, k01' and k02' each independently represent an integer of 0 to 2, k01' + k02' represents 0 or 1, k03 represents an integer of 1 to 4, k03' represents an integer of 0 to 4, k04 represents an integer of 1 to 4, Y 01 represents a group obtained by removing two hydrogen atoms from adamantane or a group obtained by removing two hydrogen atoms from norbornane, and Z 01 represents a cyclopentyl group or a cyclohexyl group, which may be substituted by a substituent selected from a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or an oxycarbonyl group, some of whose carbon atoms may be substituted by heteroatoms.

[0206] It is preferred that k01 and k02 each independently represent 0 or 1, and that k01+k02 represents 1. It is preferable that k01', k02' and k03' each represent 0. k03 and k04 each independently preferably represent an integer of 2 or 3, and more preferably represent 2.

[0207] Z 01 Examples of the halogen atom, the linear or branched alkyl group, the linear or branched acyl group, or the oxycarbonyl group in which some of the carbon atoms may be substituted with heteroatoms in Z include the same as those in Z, and preferred examples are also the same.

[0208] Z 01As the substituent of the cyclopentyl group or cyclohexyl group in the formula (I), a linear or branched alkoxy group or a linear or branched alkyl group is preferable, a methoxy group, an ethoxy group, an isopropyl group, or a tert-butyl group is more preferable, and a methoxy group or a tert-butyl group is even more preferable.

[0209] Specific examples of the anion moiety in the component (B1) are listed below: In the formula, k represents an integer of 1 to 3. However, the anion moiety in the component (B1) is not limited to these specific examples.

[0210] [ka]

[0211] [ka]

[0212] [ka]

[0213] [Cation part: (M m+ ) 1 / m ] In the general formula (b1-1), M m+ represents an m-valent organic cation. M m+ The organic cation in the formula (I) is preferably an onium cation, more preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and even more preferably a sulfonium cation or an iodonium cation. m is an integer of 1 or more.

[0214] Preferred cationic moieties ((M m+ ) 1 / m ) includes organic cations represented by the following formulas (ca-1) to (ca-3), respectively.

[0215] [ka]

[0216] [In formulas (ca-1) to (ca-3), R 201 ~R 207 each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent, and R 201 ~R 203 , R 206 ~R 207 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 210 is an optionally substituted aryl group, alkyl group, alkenyl group, or SO2-containing cyclic group, and L 201 represents -C(=O)- or -C(=O)-O-.]

[0217] R 201 ~R 207 The aryl group in the formula (I) is an aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, an arylthio group, and groups represented by the following formulas (ca-r-1) to (ca-r-7). The aryl group in the arylthio group as a substituent includes an aryl group having 6 to 20 carbon atoms, and is preferably a phenyl group, a naphthyl group, or a biphenyl group. The arylthio group includes a phenylthio group, a naphthylthio group, or a biphenylthio group.

[0218] [ka]

[0219] [In the formula, R' 201 are each independently a hydrogen atom, an optionally substituted cyclic group, a chain alkyl group, or a chain alkenyl group.

[0220] R' 201 The optionally substituted cyclic group represented by the formula (I) is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of aromatic hydrocarbon groups include aromatic hydrocarbon rings and aryl groups in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings, with phenyl and naphthyl groups being preferred. Examples of the aliphatic hydrocarbon group include groups in which one hydrogen atom has been removed from a monocycloalkane or polycycloalkane, and an adamantyl group or a norbornyl group is preferred.

[0221] R' 201 The optionally substituted chain alkyl group represented by may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a heneicosyl group, and a docosyl group.

[0222] R' 201The optionally substituted chain alkenyl group represented by may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butynyl groups. Examples of branched alkenyl groups include 1-methylpropenyl and 2-methylpropenyl groups. Of the chain alkenyl groups listed above, a propenyl group is particularly preferred.

[0223] R' 201 Examples of the optionally substituted cyclic group or optionally substituted chain alkyl group represented by formula (a1-r-2) include the same as those of the acid-dissociable group represented by formula (a1-r-2) above.

[0224] R' 201 Examples of the substituent in the cyclic group, chain alkyl group, or chain alkenyl group represented by the formula (I) include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms.

[0225] R 201~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(the R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and a thioxanium ring.

[0226] R 208 ~R 209 each 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, and when they are alkyl groups they may be bonded to each other to form a ring.

[0227] R 210 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 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210In the -SO2-containing cyclic group optionally having a substituent, the term "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring skeleton, specifically a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring containing -SO2- in the ring skeleton is counted as the first ring, and if it is the only ring, it is called a monocyclic group, and if it has other ring structures, it is called a polycyclic group regardless of the structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, i.e., a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms part of the ring skeleton. R 210 As the -SO2- containing cyclic group which may have a substituent in the above formula (a5-r-1), a group represented by the above formula (a5-r-1) is preferred. R 210 Examples of the substituent that may be possessed by include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and an arylthio group.

[0228] In an embodiment of the present invention, among the above formulas (ca-1) to (ca-3), the cation represented by formula (ca-1) is preferred, and as the cation represented by formula (ca-1), the cation represented by the following general formula (b-2) is more preferred.

[0229] [ka]

[0230] [In general formula (b-2), Rb 201 represents an aryl group which may have a substituent. Rb 202 and Rb 203 each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. Rb 201 ~Rb 203may be bonded to each other to form a ring together with the sulfur atom in general formula (b-2).

[0231] Rb 201 ~Rb 203 The optionally substituted aryl group represented by the above R 201 ~R 207 The meanings of the aryl group which may have a substituent are the same as those of the aryl group which may have a substituent, and the preferred examples are also the same. Rb 202 ~Rb 203 The optionally substituted alkyl and alkenyl groups represented by the above R 201 ~R 207 The meanings of the alkyl and alkenyl groups which may have a substituent are the same as those of the alkyl and alkenyl groups which may have a substituent, and preferred examples thereof are also the same.

[0232] Specific examples of suitable cations represented by general formula (b-2) include cations represented by the following formulas (ca-1-1) to (ca-1-67).

[0233] [ka]

[0234] [ka]

[0235] [ka]

[0236] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0237] [ka]

[0238] [In the formula, R”201 is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 The substituents are the same as those exemplified as the substituents that may be possessed by the group

[0239] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0240] [ka]

[0241] In the compound represented by general formula (b1-1), M m+ When the organic cation in is an ammonium cation, the following cations can be mentioned:

[0242] [ka]

[0243] In the compound represented by general formula (b1-1), M m+ The compound in which the organic cation is an ammonium cation is M m+ It is also useful as a synthetic intermediate for compounds in which the organic cation is a sulfonium cation or an iodonium cation.

[0244] Specific examples of suitable components (B1) are listed below.

[0245] [ka]

[0246] [ka]

[0247] In the resist composition according to this embodiment of the present invention, the component (B1) may use either a single type, or a combination of two or more types.

[0248] In the resist composition according to an embodiment of the present invention, the amount of the component (B1) relative to 100 parts by mass of the component (A) is preferably 1 to 40 parts by mass, more preferably 2.5 to 30 parts by mass, and even more preferably 5 to 25 parts by mass. When the proportion of the component (B1) is at least as large as the preferred lower limit, lithography properties such as reduced roughness and higher sensitivity are further improved, while when it is at most the upper limit, a resist pattern with excellent exposure latitude is easily formed.

[0249] About ingredient (B2) The resist composition according to an embodiment of the present invention may also contain an acid generator component other than the component (B1) (hereafter referred to as “component (B2)”), as long as the effects of the present invention are not impaired. There are no particular restrictions on the component (B2), and any of the compounds that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0250] In the resist composition according to this embodiment of the present invention, the component (B2) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (B2), the amount of the component (B2) within the resist composition is preferably no more than 30 parts by mass, and more preferably 1 to 25 parts by mass, per 100 parts by mass of the component (A). By ensuring that the amount of component (B2) in the resist composition falls within the above range, sufficient pattern formation can be achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, which is preferable as it improves the storage stability of the resist composition.

[0251] In the resist composition according to an embodiment of the present invention, the content of the acid generator component (B) is preferably 1 to 40 parts by mass, more preferably 2.5 to 30 parts by mass, and even more preferably 5 to 25 parts by mass, per 100 parts by mass of the base component (A). By ensuring that the content of acid generator component (B) in the resist composition falls within the above range, it becomes easier to obtain a resist composition that has excellent stability over time, and it also becomes easier to form a resist pattern that satisfies both high exposure latitude and high sensitivity to the exposure light source.

[0252] <Optional ingredients> The resist composition according to an embodiment of the present invention may further contain components (optional components) other than the above-mentioned components (A) and (B). Examples of such optional components include the following components (D), (E), (F), and (S).

[0253] ≪(D) ​​Component≫ The resist composition of this embodiment may further contain a base component (hereafter referred to as "component (D)") in addition to components (A) and (B). Component (D) functions as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. The component (D) may be a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its acid diffusion controllability, or a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1), but is preferably component (D1). By using a resist composition that contains the component (D), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern.

[0254] Regarding component (D1) By using a resist composition that contains the component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) is not particularly limited as long as it decomposes upon exposure to light and loses its acid diffusion controllability, and is preferably one or more acid diffusion controllers (d) selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). The resist composition of this embodiment preferably further contains an acid diffusion controller (d) containing a compound represented by any one of general formulas (d1-1) to (d1-3). The components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control properties (basicity), but act as quenchers in the unexposed areas of the resist film.

[0255] [ka]

[0256] [In the formula, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, a chain alkoxy group which may have a substituent, or a chain alkenyl group which may have a substituent, provided that Rd 2 In this case, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an m-valent organic cation.

[0257] {(d1-1) component} Anion section In formula (d1-1), Rd 1 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' 201 The same can be mentioned. Among these, Rd 1 As the substituent, an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent is preferable. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group, an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be connected via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the following formulas (y-al-1) to (y-al-8).

[0258] [ka]

[0259] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0260] In the above formula, V' 102 The divalent saturated hydrocarbon group in V' is preferably an alkylene group having 1 to 30 carbon atoms. 102 The alkylene 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.

[0261] Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0262] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine 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 atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Road 1 The alkyl group is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms, and particularly preferably a fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms (linear perfluoroalkyl group).

[0263] Preferred examples of the anion moiety of the component (d1-1) are shown below.

[0264] [ka]

[0265] Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+ Suitable organic cations include those similar to those represented by the general formulae (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the general formulae (ca-1-1) to (ca-1-67) being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0266] {(d1-2) component} Anion section In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and 201 The same can be mentioned. However, Rd 2 In this case, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not fluorinated), which makes the anion of component (d1-2) an appropriately weak acid anion, thereby improving the quenching ability of component (D). Road 2 is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a group in which one or more hydrogen atoms have been removed from camphor, etc. Road 2 The hydrocarbon group may have a substituent, and the substituent may be Rd 1 Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0267] Preferred examples of the anion moiety of the component (d1-2) are shown below.

[0268] [ka]

[0269] Cation part In formula (d1-2), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0270] {(d1-3) component} Anion section In formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and 201 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 The same fluorinated alkyl groups as those mentioned above are more preferred.

[0271] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and 201 The same can be mentioned. Among these, alkyl groups, alkoxy groups, alkenyl groups and cyclic groups which may have a substituent are preferred. Road 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4A portion of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Road 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0272] Road 4 The alkenyl group in R' 201 Examples include the same alkenyl groups as those in the above, and vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl groups are preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0273] Road 4 The cyclic group in the formula (I) is the same as the R' 201 Examples of the cyclic group include the same as the cyclic group in the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or aromatic groups such as a phenyl group or a naphthyl group. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. 4 When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0274] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples thereof include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have a substituent, and divalent linking groups containing a hetero atom. These are the same as Ya in the above general formula (a2-1), 21 Examples of the divalent linking group include the same divalent hydrocarbon groups which may have a substituent and divalent linking groups containing a hetero atom as those mentioned in the description of the divalent linking group in the above. Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0275] Preferred examples of the anion moiety of the component (d1-3) are shown below.

[0276] [ka]

[0277] [ka]

[0278] Cation part In formula (d1-3), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0279] The component (D1) may be any one of the components (d1-1) to (d1-3) above, or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) within the resist composition, relative to 100 parts by mass of the component (A), is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2.5 to 15 parts by mass. When the amount of the component (D1) is at least as large as the lower limit of the preferred range, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is at most the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0280] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0281] Regarding component (D2) The acid diffusion controller component may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above-mentioned component (D1). The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of component (D1), and any known amine may be used. Among these, aliphatic amines or aromatic amines are preferred, and aromatic amines are more preferred.

[0282] The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. 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 is particularly preferred.

[0283] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specific examples thereof 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.

[0284] 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, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0285] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0286] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A). By ensuring this range, the resist pattern shape and stability over time during storage can be improved.

[0287] <Component (E): At least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof> The resist composition according to an embodiment of the present invention may contain, as an optional component, at least one compound (E) (hereafter referred to as "component (E)") selected from the group consisting of organic carboxylic acids, phosphorus oxo acids, and derivatives thereof, for the purposes of preventing sensitivity degradation and improving the resist pattern shape and stability over time during exposure. Suitable organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atoms of the above oxoacids are substituted with hydrocarbon groups, and examples of the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid.

[0288] Of the above, component (E) is preferably an organic carboxylic acid, more preferably an aromatic carboxylic acid, specifically benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, or isophthalic acid, more preferably salicylic acid.

[0289] In the resist composition according to this embodiment of the present invention, the component (E) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) relative to 100 parts by mass of the component (A) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass.

[0290] <(F) Component: Fluorine additive component> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film, and when used as a resin separate from component (A), it improves lithography properties. As the component (F), for example, the fluorine-containing polymer compounds described in JP-A Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 can be used. More specific examples of the component (F) include polymers having a structural unit (f11) represented by the following general formula (f1-1) or a structural unit (f12) represented by the following general formula (f1-2).

[0291] The polymer having the structural unit (f11) represented by the following general formula (f1-1) is preferably a polymer (homopolymer) consisting solely of the structural unit (f11) represented by the following formula (f1-1); a copolymer of the structural unit (f11) with the structural unit (a1); or a copolymer of the structural unit (f11), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f11) is preferably a structural unit containing an acid-dissociable group represented by the above formula (a1-r2-1).

[0292] Examples of polymers having the structural unit (f12) represented by the following general formula (f1-2) include polymers (homopolymers) consisting solely of the structural unit (f12) represented by the following general formula (f1-2), and copolymers of the structural unit (f12) with the structural unit (a1). Of these, copolymers of the structural unit (f12) with the structural unit (a1) are preferred.

[0293] [ka]

[0294] [In the formula, R is the same as R in the general formula (a1-1).102 and Rf 103 each 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; Rf 102 and Rf 103 may be the same or different. 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom. 11 ~Rf 12 Rf are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms. 13 Rf is a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms. 14 is a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear fluorinated alkyl group having 1 to 4 carbon atoms.]

[0295] In general formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In general formula (f1-1), Rf 102 and Rf 103 Examples of the halogen atom in Rf include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms for R include the same alkyl groups having 1 to 5 carbon atoms as those for R, and a methyl group or an ethyl group is preferred. 102 and Rf 103 Specific examples of the halogenated alkyl group 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 have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. Among these, Rf 102 and Rf 103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group. In general formula (f1-1), n f1is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and even more preferably 1 or 2.

[0296] In general formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group 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 the fluorine atom-containing hydrocarbon group, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more, because this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, further preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, -CH2-CH2-CF2-CF2-CF2-CF3, and particularly preferably -CH2-CF3.

[0297] In general formula (f1-2), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In the general formula (f1-2), Rf 11 ~Rf 12 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms. Rf 11 ~Rf 12 The alkyl group having 1 to 4 carbon atoms in the formula (I) may be linear, branched, or cyclic, and is preferably a linear or branched alkyl group. Specific examples of suitable groups include a methyl group and an ethyl group, and an ethyl group is particularly preferred. Rf 11 ~Rf 12The fluorinated alkyl group having 1 to 4 carbon atoms in the formula (I) is a group in which some or all of the hydrogen atoms in the alkyl group having 1 to 4 carbon atoms have been substituted with fluorine atoms. In the fluorinated alkyl group, the alkyl group that is not substituted with fluorine atoms may be linear, branched, or cyclic, and may be any of the alkyl groups described above in "Rf 11 ~Rf 12 Examples thereof include the same as the alkyl group having 1 to 4 carbon atoms in the above formula. Among the above, Rf 11 ~Rf 12 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Rf 11 ~Rf 12 It is particularly preferred that one of them is a hydrogen atom and the other is an alkyl group having 1 to 4 carbon atoms.

[0298] In the general formula (f1-2), Rf 13 is a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms. Rf 13 The fluorinated alkyl group having 1 to 4 carbon atoms in the formula (I) is the same as that in the formula (I) above. 11 ~Rf 12 The fluorinated alkyl group having 1 to 4 carbon atoms in the above formula (II) is preferably a fluorinated alkyl group having 1 to 3 carbon atoms, and more preferably a fluorinated alkyl group having 1 to 2 carbon atoms. Rf 13 In the fluorinated alkyl group, the ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms contained in the fluorinated alkyl group (fluorination rate (%)) is preferably 30 to 100%, more preferably 50 to 100%. The higher the fluorination rate, the higher the hydrophobicity of the resist film. Among the above, Rf 13 is preferably a fluorine atom.

[0299] In the general formula (f1-2), Rf 14 is a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear fluorinated alkyl group having 1 to 4 carbon atoms, and is preferably a linear alkyl group having 1 to 4 carbon atoms, or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Rf14 Specific examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Of these, a methyl group and an ethyl group are preferred, and a methyl group is most preferred. Rf 14 Specific examples of the fluorinated alkyl group in the formula (I) include -CH2-CF3, -CH2-CH2-CF3, -CH2-CF2-CF3, and -CH2-CF2-CF2-CF3-CF3, and among these, -CH2-CH2-CF3 is particularly preferred. stomach.

[0300] The weight-average molecular weight (Mw) of component (F) (based on polystyrene standards measured 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. When the Mw is below the upper limit of this range, the resin has sufficient solubility in a resist solvent for use as a resist, while when the Mw is above the lower limit of this range, the resin has good dry etching resistance and the resist pattern has good cross-sectional shape. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0301] In the resist composition of this embodiment, the component (F) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (F), the component (F) is typically used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the component (A).

[0302] <Component (S): Organic solvent component> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as “component (S)”). The component (S) can be any solvent that can dissolve the various components used and form a homogeneous solution, and can be selected from any of the solvents known to date for chemically amplified resist compositions. In the resist composition of this embodiment, the component (S) can be used alone, or as a mixed solvent of two or more different solvents. Among the above, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, propylene carbonate, ethyl lactate (EL), and cyclohexanone are preferred, and PGMEA, PGME, and cyclohexanone are more preferred. A mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, and is preferably within the range of 1:9 to 9:1, and more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with at least one selected from γ-butyrolactone and propylene carbonate, in which the mass ratio of the former to the latter is preferably 60:40 to 99:1, more preferably 70:30 to 95:5. There are no particular restrictions on the amount of component (S) used, and it is set appropriately depending on the coating film thickness so as to provide a concentration that allows application to a substrate, etc. Generally, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 15 mass %.

[0303] The resist composition of this embodiment may further contain, if desired, compatible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0304] A resist composition according to an embodiment of the present invention contains the above-mentioned components (A) and (B), and, if necessary, the above-mentioned optional components. Suitable examples include resist compositions containing the component (A), the component (B), and the component (D). Further suitable examples include resist compositions containing the component (A), the component (B), the component (D), and the component (F).

[0305] As explained above, the resist composition according to an embodiment of the present invention contains the base component (A) and acid generator component (B) described above. By including the compound (b1-1) having a specific structure, the acid generator component (B) in the resist composition can impart stability to acids and bases and appropriate bulkiness to the anion moiety. As a result, it is believed that reaction with other components in the composition is suppressed, and diffusion during baking is controlled within an appropriate range, making it possible to form a resist pattern that exhibits excellent stability over time and exhibits both high exposure latitude and high sensitivity to the exposure light source.

[0306] [Method of forming a resist pattern] A method for forming a resist pattern 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 of the above-described embodiment, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of the resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0307] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 50 to 90 seconds, to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an EUV exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with electron beams without using a mask pattern, and then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process. After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, it is preferable to use a rinse solution containing an organic solvent. In the case of a solvent development process, the developing treatment or rinsing treatment may be followed by a treatment of removing the developing solution or rinsing solution adhering to the pattern using a supercritical fluid. After the development treatment or rinsing treatment, the film is dried. In some cases, a baking treatment (post-baking) may be performed after the development treatment.

[0308] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0309] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used.

[0310] The exposure method for the resist film may be a normal exposure (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography, but liquid immersion lithography is preferred. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is 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. The immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed. The refractive index of such a solvent is not particularly limited as long as it is within the above range. Examples of solvents having a refractive index greater than that of air and smaller than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. As the immersion medium, water is preferably used.

[0311] The alkaline developer used in the development treatment in the alkaline development process may be, for example, a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents. Ketone-based solvents are organic solvents that contain CC(=O)-C or CC(=O)-H in their structure. Ester-based solvents are organic solvents that contain CC(=O)-OC or HC(=O)-OC in their structure. Alcohol-based solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. "Alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile-based solvents are organic solvents that contain a nitrile group in their structure. Amide-based solvents are organic solvents that contain an amide group in their structure. Ether-based solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple types of functional groups that characterize the above-mentioned solvents in their structure, and in such cases, the term "organic solvent" refers to any solvent type containing the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is considered to be both an alcohol-based solvent and an ether-based solvent in the above classification. The hydrocarbon solvent is a hydrocarbon solvent that is composed of a hydrocarbon that may be halogenated and has no substituents other than halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, and fluorine atoms are preferred. Of the above, the organic solvent contained in the organic developer is preferably a polar solvent, and more preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

[0312] Examples of the ester solvent include methyl acetate, butyl acetate, and ethyl acetate.

[0313] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0314] Known additives can be added to the organic developer as needed. Examples of such additives include surfactants. The surfactants are not particularly limited, but examples include ionic and nonionic fluorine-based and / or silicon-based surfactants.

[0315] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0316] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be selected appropriately from the organic solvents listed above as organic solvents used in the organic developer, so long as it does not easily dissolve the resist pattern. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination of two or more, and may be used in combination with other organic solvents or water.

[0317] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0318] The resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of metal-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and salts thereof. The impurity content of 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).

[0319] In the method of forming a resist pattern according to the embodiment of the present invention described above, the resist composition according to the embodiment of the present invention is used, and therefore it is possible to form a resist pattern that satisfies both exposure latitude and high sensitivity to the exposure light source.

[0320] 〔salt〕 The salt according to the third aspect of the present invention is a salt represented by the general formula (b1-1) (hereinafter referred to as "compound (b1-1)"). The compound (b1-1) is the same as the component (B1) in the resist composition according to the first aspect of the present invention.

[0321] The compound (b1-1) can be produced by a conventional method. As a specific example, in the compound (b1-1), the divalent polycyclic hydrocarbon group represented by Y is a group having an adamantane skeleton, the linking group represented by L is an ester bond (—CO—O—), and M m+ is triphenylsulfonium, the compound (hereinafter referred to as "compound (b1-1-4)") is m+ It can be produced as follows via an intermediate compound (compound (b1-1-3) below) which is not a triphenylsulfonium compound.

[0322] [ka]

[0323] [In general formulas (b1-1-1) to (b1-1-4), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group, and Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Z represents a substituent represented by the above formula (bz-1). m represents an integer of 1 or more, M m+ represents an m-valent organic cation.

[0324] Rf in general formulas (b1-1-1) to (b1-1-4) 01 , Rf 02 , X, Z, m, M m+ are Rf in the general formula (b1-1), respectively. 01 , Rf 02 , X, Z, m, M m+ The same applies to the above and preferred terms.

[0325] First, the compound represented by general formula (b1-1-1) is added to an organic solvent (e.g., acetonitrile, acetone, dichloromethane, tetrahydrofuran, etc.) and cooled. Then, in the presence of a base (triethylamine, pyridine, 4-(dimethylamino)pyridine, etc.), a solution of the compound represented by general formula (b1-1-2) dissolved in an organic solvent is added and reacted. After separation and washing with water, the compound represented by general formula (b1-1-3) is obtained from the organic phase.

[0326] When further salt exchange is carried out, compound (b1-1-3) is dissolved in a mixed solvent of an organic solvent (e.g., dichloromethane, tetrahydrofuran, etc.) and water, and a compound containing the desired cation (triphenylsulfonium bromide in the above example) is added thereto to react, followed by separation and washing with water, and then compound (b1-1-4) is recovered from the organic phase.

[0327] As described above, among the salts represented by general formula (b1-1), M m+ The salt in which the organic cation is an ammonium cation is M m+ It is also useful as an intermediate for synthesizing salts in which the organic cation is a sulfonium cation or an iodonium cation.

[0328] The structure of the resulting compound is: 1 H-nuclear magnetic resonance (NMR) spectroscopy, 13 C-NMR spectroscopy, 19 This can be confirmed by common organic analysis methods such as F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

[0329] The above-mentioned compound (b1-1) is a novel compound that has not been known before. Furthermore, the compound (b1-1) is a novel compound that is useful as an acid generator for a resist composition, and can be blended into the resist composition as an acid generator.

[0330] The compound represented by the general formula (b1-1) is useful as an acid generator. An acid generator comprising a compound represented by general formula (b1-1) is useful as an acid generator for a chemically amplified resist composition, for example, as the acid generator component (B) of the resist composition according to the first aspect of the present invention. [Example]

[0331] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0332] <Synthesis of Acid Generator Component (B)> In the present examples, the compounds used as the acid generator component (B) were synthesized according to the synthesis examples shown below.

[0333] (Synthesis example of compound (B-1)) The compound represented by formula (1-1) (30 g), acetonitrile (130 g), and triethylamine (9.2 g) were mixed, and a solution of cyclohexanecarbonyl chloride (10.6 g) in acetonitrile (20 g) was added dropwise thereto, followed by stirring at room temperature for 48 hours. The resulting reaction solution was filtered, and the filtrate was concentrated to obtain a residue. The residue was dissolved in dichloromethane (150 g), water (200 g) was added, and the mixture was stirred at room temperature for 30 minutes, and the organic phase was separated. This water washing procedure was repeated five times. The collected organic phase was concentrated to obtain the salt (27 g) represented by formula (B1-1-1). The salt represented by formula (B1-1-1) (20 g), dichloromethane (200 g), triphenylsulfonium bromide (formula (2-1)) (14.9 g), and ion-exchanged water (115 g) were mixed and stirred at room temperature for 30 minutes, after which the organic phase was separated. Next, ion-exchanged water (115 g) was added to the separated organic phase, and after stirring at room temperature for 30 minutes, the organic phase was separated. This water washing procedure was repeated eight times. Next, the obtained organic phase was concentrated to obtain the salt represented by formula (B-1) (compound (B-1)) (21 g).

[0334] Compound (B-1) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.97(m,1H),4.30-4.05(m,2H),2.46-1.40(m,22H),1.40-1.10(m,5H). From the above results, it was confirmed that compound (B-1) had the structure shown below.

[0335] [ka]

[0336] (Synthesis example of compound (B-2)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that cyclohexanecarbonyl chloride (10.6 g) was replaced with cyclopentanecarbonyl chloride (9.6 g), thereby obtaining compound (B-2).

[0337] The compound (B-2) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.97(m,1H),4.30-4.05(m,2H),2.46-1.10(m,25H).

[0338] (Synthesis example of compound (B-3)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that cyclohexanecarbonyl chloride (10.6 g) was replaced with 4-tert-butylcyclohexanecarbonyl chloride (14.7 g), thereby obtaining compound (B-3).

[0339] The compound (B-3) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.97(m,1H),4.30-4.05(m,2H),2.46-0.62(m,35H).

[0340] (Synthesis example of compound (B-4)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that cyclohexanecarbonyl chloride (10.6 g) was replaced with 3-methoxycyclohexanecarbonyl chloride (12.8 g), thereby obtaining compound (B-4).

[0341] The compound (B-4) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.97(m,1H),4.30-4.05(m,2H),3.65-1.10(m,29H).

[0342] (Synthesis example of compound (B-5)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that the compound (30 g) represented by the above formula (1-1) was replaced with the compound (30.7 g) represented by the following formula (1-2). As a result, compound (B-5) was obtained.

[0343] [ka]

[0344] The compound (B-5) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.63-4.32(m,2H),2.80-2.55(m,2H),2.46-1.10(m,25H).

[0345] (Synthesis example of compound (B-6)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that the compound (30 g) represented by formula (1-1) was replaced with the compound (31.0 g) represented by the following formula (1-3). As a result, compound (B-6) was obtained.

[0346] [ka]

[0347] The compound (B-6) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.31-4.19(m,2H),2.65-1.10(m,27H).

[0348] (Synthesis example of compound (B-7)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that triphenylsulfonium bromide (formula (2-1)) (14.9 g) was replaced with the compound (15.5 g) represented by the following formula (2-2). As a result, compound (B-7) was obtained.

[0349] [ka]

[0350] The compound (B-7) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.61(m,14H),4.97(m,1H),4.30-4.05(m,2H),2.48-1.40(m,25H),1.40-1.10(m,5H).

[0351] (Synthesis example of compound (B-8)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that triphenylsulfonium bromide (formula (2-1)) (14.9 g) was replaced with the compound (25.8 g) represented by the following formula (2-3). As a result, compound (B-8) was obtained.

[0352] [ka]

[0353] Compound (B-8) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.61(m,12H),4.97(m,1H),4.61(s,2H),4.30-4.05(m,2H),2.49-1.10(m,50H).

[0354] (Synthesis example of compound (B-9)) The same procedure was carried out as in the synthesis of the above compound (B-1), except that the compound (30 g) represented by formula (1-1) was replaced with the compound (27.8 g) represented by the following formula (1-4), thereby obtaining compound (B-9).

[0355] [ka]

[0356] The compound (B-9) was analyzed by NMR. 1 H NMR(400MHz,DMSO-d6)δ(ppm)=7.93-7.69(m,15H),4.97(m,1H),4.30-4.05(m,2H),3.65-1.10(m,23H).

[0357] From the above results, it was confirmed that the compounds (B-1) to (B-9) had the structures shown below.

[0358] [ka]

[0359] [ka]

[0360] A polymer compound (A-1) containing the structural units shown below in a composition ratio (molar ratio) of (l:m=50:50) was synthesized. The resulting polymer compound had a weight average molecular weight (Mw) of 11,000 and a molecular weight dispersity (Mw / Mn) of 1.6, as determined by GPC measurement and calculated using standard polystyrene standards.

[0361] [ka]

[0362] <Preparation of Resist Composition> (Examples 1 to 15, Comparative Examples 1 to 7) The components shown in Table 1 were mixed and dissolved in a solvent: S-1 to prepare resist compositions of the respective examples. S-1: a mixed solvent of 1,750 parts by mass of propylene glycol monomethyl ether acetate, 640 parts by mass of propylene glycol monomethyl ether, and 800 parts by mass of cyclohexanone

[0363] [Table 1]

[0364] In Table 1, the abbreviations have the following meanings: A-1: The above polymer compound A-1 B-1 to B-9: Acid generators composed of compounds represented by the above chemical formulas B-1 to B-9 B-X1 to B-X5: Acid generators composed of compounds represented by the following chemical formulas B-X1 to B-X5 D-1: An acid diffusion controller consisting of a compound represented by the following chemical formula D-1. F-1: Hydrophobic resin F-1 containing the following structural unit (composition ratio (molar ratio): l / m = 80 / 20, Mw: 25000, Mw / Mn: 1.5)

[0365] [ka]

[0366] [ka]

[0367] <Formation of Resist Pattern> An organic anti-reflective coating composition "SOC110D" (manufactured by Brewer Science) was applied to a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, forming an organic anti-reflective coating with a thickness of 137 nm. Furthermore, a hard mask "HM825" (manufactured by Brewer Science) was applied onto the anti-reflective film using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, thereby forming a hard mask layer with a thickness of 30 nm. The resist composition was applied onto the above-mentioned base substrate using a spinner, prebaked (PAB) on a hot plate at 100°C for 60 seconds, and dried to form a resist film with a thickness of 100 nm.

[0368] The wafer was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) using an XT1900Gi ArF immersion exposure system (manufactured by ASML; NA (numerical aperture) = 1.35, Dipole 90X, Sigma (Ont 0.97, In 0.78) TE-pol, immersion medium: ultrapure water). Then, a PEB process was performed at 120°C for 60 seconds.

[0369] Next, alkaline development was performed for 15 seconds using a 2.38% by mass TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by rinsing with pure water for 15 seconds and then shaking off and drying. As a result, line and space patterns (hereinafter referred to as LS patterns) with a line dimension of 40 nm and a pitch of 80 nm (mask size 40 nm) were formed.

[0370] [Evaluation of sensitivity (optimum exposure amount)] The line size was observed using a length-measuring SEM (scanning electron microscope, accelerating voltage 500 V, product name: CG5000, manufactured by Hitachi High-Technologies Corporation), and the optimal exposure dose (mJ / cm) was determined as the exposure dose that would form an LS pattern with a line dimension of 40 nm and a pitch of 80 nm. 2) The results are shown in Table 1.

[0371] [Exposure Latitude (E L) Evaluation] When the exposure dose was varied around the above-mentioned optimum exposure dose, the fluctuation range of the exposure dose that allows a line width of 40 nm ± 5% was determined, and this value was divided by the optimum exposure dose to express it as a percentage. The larger the value, the smaller the change in performance due to changes in exposure dose, and the better the exposure latitude.

[0372] [Evaluation of stability over time] After storing each composition of the Examples and Comparative Examples at room temperature for two months, the composition was exposed to light at the optimum exposure dose at the time of initial evaluation, and the line dimension was measured in the same manner as above to determine the deviation from the value at the time of initial evaluation. The smaller the absolute value of this deviation, the less likely the resist composition is to deteriorate and the better its stability over time.

[0373] The results shown in Table 1 confirm that the resist compositions of the examples to which the present invention is applied have excellent stability over time and are capable of forming resist patterns that combine high exposure latitude and high sensitivity to the exposure light source.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, The composition contains a base component (A) whose solubility in a developer changes under the action of an acid, and an acid generator component (B) that generates an acid upon exposure to light, The resist composition, wherein the acid generator component (B) contains a compound represented by the following general formula (b1-1): 【Chemistry 1】 [In general formula (b1-1), Rf ０１ and Rf ０２ each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; Rf ０１ , Rf ０２ At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M ｍ＋ represents an m-valent organic cation. 【Chemistry 2】 [In formula (bz-1), R １ each independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W is an oxygen atom, a sulfur atom, or —NR ｎ represents -, and R ｎ represents a hydrogen atom or a linear or branched alkyl group. m1 and n1 represent integers of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.

2. 2. The resist composition according to claim 1, wherein the polycyclic hydrocarbon group represented by Y in said general formula (b1-1) has an adamantane skeleton or a norbornane skeleton.

3. M in the general formula (b1-1) ｍ＋ The resist composition according to claim 1 or 2, wherein is a cation represented by the following general formula (b-2): 【Transformation 3】 [In general formula (b-2), Rb ２０１ represents an aryl group which may have a substituent. Rb ２０２ and Rb ２０３ each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. Rb ２０１ ~Rb ２０３ may be bonded to each other to form a ring together with the sulfur atom in general formula (b-2).

4. 3. The resist composition according to claim 1, wherein the content of said acid generator component (B) is 1 to 40 parts by mass per 100 parts by mass of said base component (A).

5. 3. The resist composition according to claim 1, wherein the base component (A) contains a polymeric compound (A1) having a structural unit (a1) represented by the following general formula (a1-1): 【Chemistry 4】 (In general formula (a1-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ３ represents a divalent linking group. na ３ represents an integer of 0 to 2. Ra ０３１ represents an alkyl group, and Yab ０ represents a carbon atom. Xab ０ is Yab ０ represents a group which, together with

6. The polymer compound (A1) further contains a lactone-containing cyclic group, —SO ２ 6. The resist composition according to claim 5, which comprises a structural unit (a2) that includes a -containing cyclic group or a carbonate-containing cyclic group.

7. 3. The resist composition according to claim 1, further comprising an acid diffusion controller (d) containing a compound represented by any one of the following general formulas (d1-1) to (d1-3): 【Transformation 5】 [In general formulas (d1-1) to (d1-3), Rd １ ~Rd ４ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula (I), no fluorine atom is bonded to the carbon atom adjacent to the S atom. Yd １ represents a single bond or a divalent linking group. m represents an integer of 1 or more, M ｍ＋ each independently represents an m-valent organic cation.

8. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition according to claim 1; exposing the resist film to light; and developing the resist film to form a resist pattern.

9. A salt represented by the following general formula (b1-1): 【Transformation 6】 [In general formula (b1-1), Rf ０１ and Rf ０２ each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; Rf ０１ , Rf ０２ At least one of them contains a fluorine atom. X represents a divalent linking group having a total of 4 or more atoms in the main chain, and the divalent linking group represents an alkylene group which may contain an ester bond or an ether bond, a fluorinated alkylene group which may contain an ester bond or an ether bond, or a combination thereof, provided that neither the ester bond nor the ether bond in X is adjacent to each other to form an acetal bond. Y represents a divalent polycyclic hydrocarbon group which may have a substituent. L represents a divalent linking group containing an ester bond or an oxygen atom, and a plurality of ester bonds and a plurality of oxygen atoms may be bonded independently via alkylene groups. Z represents a substituent represented by the following formula (bz-1). m represents an integer of 1 or more, M ｍ＋ represents an m-valent organic cation. 【Transformation 7】 [In formula (bz-1), R １ each independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group, a linear or branched acyl group, or a linear or branched alkyloxycarbonyl group, some of the carbon atoms of which may be substituted with heteroatoms. W represents an oxygen atom, a sulfur atom, or an amino group which may be substituted with a linear or branched alkyl group. m1 and n1 represent integers of 0 to 4, and m1+n1 is an integer of 0 to 4. * represents a bond.

10. The salt according to claim 9, wherein the polycyclic hydrocarbon group represented by Y in general formula (b1-1) has an adamantane skeleton or a norbornane skeleton.

11. M in the general formula (b1-1) ｍ＋ is a cation represented by the following general formula (b-2): 【Transformation 8】 [In general formula (b-2), Rb ２０１ represents an aryl group which may have a substituent. Rb ２０２ and Rb ２０３ each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. Rb ２０１ ~Rb ２０３ may be bonded to each other to form a ring together with the sulfur atom in general formula (b-2).

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