Resist composition and method for forming a resist pattern

Abstract

To provide a resist composition having both good sensitivity and DOF, and a resist pattern forming method.SOLUTION: The resist composition contains a resin component having a constituent unit represented by general formula (a0-1) and an acid generator component containing a compound represented by general formula (b1-1). In the formulae, Ra00 is an acid-dissociable group represented by general formula (a0-r1-1); Ra01 and Ra02 are each a hydrocarbon group; one of Ra031, Ra032 and Ra033 is a hydrocarbon group having an ether bond; Rb01 is a polycyclic hydrocarbon group having a hydroxy group; Yb01 is a divalent linking group containing an oxygen atom, or the like; Vb01 is a fluorinated alkylene group or the like; and Rb02 is a fluorine atom or the like.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In recent years, advances in lithography technology have led to rapid advances in the miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display devices. A common method for achieving this miniaturization is to shorten the wavelength (increase the energy) of the exposure light source.

[0003] 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 a base component whose solubility in a developer changes due to the action of acid, and an acid generator component that generates acid upon exposure.

[0004] Chemically amplified resist compositions generally contain resins having multiple structural units in order to improve lithography properties and the like. For example, Patent Document 1 describes a resist composition that employs a specific polymer compound with high acid dissociation performance to improve reactivity to acids. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-060066 Summary of the Invention [Problem to be solved by the invention]

[0006] Advances in lithography technology have led to rapid progress in miniaturization of patterns, but as resist pattern dimensions become smaller, resist compositions are required to have higher sensitivity to the exposure light source. Furthermore, improvements in depth of focus (DOF) characteristics are also required to improve process margins and other aspects of resist pattern formation. "DOF" refers to the range of depth of focus within which a resist pattern can be formed with a size that is within a specified range of deviation from the target size when exposed with the same exposure dose but with the focus shifted up or down, i.e., the range within which a resist pattern that is faithful to the mask pattern can be obtained; the larger this value, the better.

[0007] However, when a conventional polymer compound such as that described in Patent Document 1 is used, although high sensitivity can be achieved, it is difficult to achieve both high sensitivity and DOF at the same time.

[0008] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a resist composition that exhibits both excellent sensitivity and DOF, and a method of forming a resist pattern that uses the resist composition. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect 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 resist composition contains a resin component (A1) 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, wherein the resin component (A1) has a structural unit (a01) represented by the following general formula (a0-1), and the acid generator component (B) contains a compound (B1) represented by the following general formula (b1-1).

[0010] [ka] [wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. 0 is a divalent hydrocarbon group which may have an ether bond. a0 is an integer from 0 to 2. 00 is an acid-dissociable group represented by general formula (a0-r1-1). 01 and Ra 02 Each of Ra is independently a hydrocarbon group which may have a substituent. 01 and Ra 02 and may be bonded to each other to form a ring structure. 031 , Ra 032 and Ra 033 are each independently a hydrogen atom or a hydrocarbon group which may have a substituent. 031 , Ra 032 and Ra 033 At least one of the groups is a hydrocarbon group having an ether bond. * indicates a bond.]

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

[0012] According to the present invention, it is possible to provide a resist composition that exhibits both excellent sensitivity and DOF, and a method of forming a resist pattern that uses the resist composition. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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. The "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "may have a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is a general concept that includes irradiation with radiation.

[0014] 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 hydroxyl group, an amino group, and a sulfo group (-SO3H). 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).

[0015] 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.

[0016] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly divided into non-polymers and polymers. Non-polymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, the term "low molecular weight compound" refers to a non-polymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, the terms "resin," "high molecular weight compound," or "polymer" refer to a polymer with a molecular weight of 1000 or more. The molecular weight of a polymer is determined by the weight average molecular weight converted into polystyrene by GPC (gel permeation chromatography).

[0017] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, such as an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. αx ) is an atom or group other than a hydrogen atom. αx ) is substituted with a substituent containing an ester bond, or αx 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 carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic ester.

[0018] The term "derivative" encompasses compounds in which the hydrogen atom at the α-position of the target compound is substituted with another substituent, such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of a hydroxyl group of a target compound, which may have the hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; and compounds in which a substituent other than a hydroxyl group is bonded to a target compound, which may have the hydrogen atom at the α-position substituted with a substituent. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. The substituents that replace the hydrogen atom at the α-position of hydroxystyrene include R αx The same can be mentioned.

[0019] 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.

[0020] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility in a developer changes due to the action of the acid. Such a resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of acid, and an acid generator component (B) (hereinafter also referred to as "component (B)") that generates acid upon exposure.

[0021] When a resist film is formed using the resist composition of this embodiment and then subjected to selective exposure, an acid is generated from the component (B) in the exposed areas of the resist film, and the solubility of the component (A) in a developer changes due to the action of the acid. However, the solubility of the 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.

[0022] The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this embodiment may be for use in an alkaline development process in which an alkaline developer is used for the development treatment during resist pattern formation, or may be for use in a solvent development process in which an organic developer is used for the development treatment. In other words, the resist composition of this embodiment is a "positive resist composition for an alkaline developing process" that forms a positive resist pattern in an alkaline developing process, and a "negative resist composition for a solvent developing process" that forms a negative resist pattern in a solvent developing process.

[0023] <Component (A)> In the resist composition of this embodiment, the component (A) contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid, and the resin component (A1) has a structural unit (a01) represented by general formula (a0-1). As the component (A), at least the component (A1) is used, and at least one of another polymeric compound and a low molecular weight compound may be used in combination with the component (A1).

[0024] In the resist composition of this embodiment, the component (A) may use either a single type of compound, or a combination of two or more types of compounds.

[0025] About component (A1) The component (A1) has a structural unit (a01).

[0026] <Constituent unit (a01)> The structural unit (a01) is a structural unit represented by the following general formula (a0-1).

[0027] [ka] [wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. 0 is a divalent hydrocarbon group which may have an ether bond. a0 is an integer from 0 to 2. 00 is an acid-dissociable group represented by general formula (a0-r1-1). 01 and Ra 02 Each of Ra is independently a hydrocarbon group which may have a substituent. 01 and Ra 02 and may be bonded to each other to form a ring structure. 031 , Ra 032 and Ra 033 are each independently a hydrogen atom or a hydrocarbon group which may have a substituent. 031 , Ra 032 and Ra 033 At least one of the groups is a hydrocarbon group having an ether bond. * indicates a bond.]

[0028] In the formula (a0-1), 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 for 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 for R 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. 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. 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, more preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability, and even more preferably a methyl group.

[0029] In the formula (a0-1), Va 0 is a divalent hydrocarbon group which may have an ether bond. Va 0 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0030] Va 0 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.

[0031] 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.

[0032] 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 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is 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. A preferred polycyclic alicyclic hydrocarbon group is a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0033] Va 0 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 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 10. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. 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. 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.

[0034] In the formula (a0-1), n a0 is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0035] In the formula (a0-1), Ra 00is an acid-dissociable group represented by the general formula (a0-r1-1) above. Such an acid-dissociable group protects the oxy group (-O-) of the carbonyloxy group [-C(=O)-O-] in formula (a0-1). The "acid-dissociable group" here has acid dissociability such that the bond between the acid-dissociable group and the oxygen atom (O) adjacent to the acid-dissociable group can be cleaved by the action of an acid. When the acid-dissociable group dissociates by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, thereby increasing polarity. As a result, the polarity of the entire component (A1) increases. The increased polarity relatively changes the solubility in the developer, increasing solubility when the developer is an alkaline developer and decreasing solubility when the developer is an organic developer.

[0036] In the formula (a0-r1-1), * represents a bond bonded to the oxy group (—O—) of the carbonyloxy group [—C(═O)—O—] in the formula (a0-1).

[0037] In the formula (a0-r1-1), Ra 01 and Ra 02 Each of Ra is independently a hydrocarbon group which may have a substituent. 01 and Ra 02 may be bonded to each other to form a ring structure. Ra 01 and Ra 02 The hydrocarbon groups in each of the above may independently be a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group.

[0038] Ra 01 and Ra 02 The 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, and an n-pentyl group. Of 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. Ra 01 and Ra 02The 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, with an isopropyl group being preferred. Ra 01 and Ra 02 The chain or cyclic alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 10 carbon atoms.

[0039] Ra 01 and Ra 02 The cyclic hydrocarbon group in 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 is preferably one having 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0040] Ra 01 and Ra 02The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having at least one aromatic ring. This 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 number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are 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 a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group); 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., 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 alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2, and particularly preferably 1.

[0041] The above Ra 01 and Ra 02 When the hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group), an alkyloxycarbonyl group, and the like.

[0042] In the formula (a0-r1-1), Ra 01 and Ra 02 may be bonded to each other to form a ring structure. Ra 01 and Ra 02Examples of the ring structure formed by Ra include an alicyclic hydrocarbon group and a condensed ring of an alicyclic hydrocarbon and an aromatic hydrocarbon. 01 and Ra 02 The ring structure formed by these may contain a heteroatom.

[0043] Ra 01 and Ra 02 The alicyclic hydrocarbon group formed by these may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two or more hydrogen atoms have 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 two hydrogen atoms have 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.

[0044] Ra 01 and Ra 02 The alicyclic hydrocarbon portion in the fused ring formed by these may be monocyclic or polycyclic, and the aromatic hydrocarbon portion may be monocyclic or polycyclic. The fused ring may have a substituent, such as a methyl group, an ethyl group, a propyl group, a hydroxy group, a hydroxyalkyl group, a carboxy group, a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom), an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), an acyl group, an alkyloxycarbonyl group, or an alkylcarbonyloxy group. Below, Ra 01 and Ra 02 Specific examples of the fused ring formed by the above are shown below.

[0045] [ka]

[0046] In the formula (a0-r1-1), Ra 01 and Ra 02 are preferably bonded to each other to form a ring structure, more preferably bonded to each other to form an alicyclic hydrocarbon group, and even more preferably bonded to each other to form a monocyclic alicyclic hydrocarbon group, because this tends to further improve lithography properties.

[0047] Ra 031 , Ra 032 and Ra 033 are each independently a hydrogen atom or a hydrocarbon group which may have a substituent. Ra 031 , Ra 032 and Ra 033 The hydrocarbon group which may have a substituent is represented by Ra in the formula (a0-r1-1). 01 and Ra 02 Among these, the hydrocarbon groups which may have a substituent in Ra 031 , Ra 032 and Ra 033 The hydrocarbon group in the formula (I) which may have a substituent is preferably a linear or branched alkyl group which may have a substituent, more preferably a linear alkyl group, and even more preferably a linear alkyl group having 1 to 5 carbon atoms.

[0048] In the formula (a0-r1-1), Ra 031 , Ra 032 and Ra 033 are each independently preferably a hydrogen atom or a linear or branched alkyl group which may have a substituent, more preferably a hydrogen atom or a linear alkyl group which may have a substituent, and even more preferably a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

[0049] However, Ra 031 , Ra 032 and Ra 033 At least one of the groups is a hydrocarbon group having an ether bond (—O—). The hydrocarbon group in the hydrocarbon group having an ether bond is, for example, Ra in the above formula (a0-r1-1). 01 and Ra 02 Examples of the hydrocarbon groups include the same hydrocarbon groups as those in the optionally substituted hydrocarbon groups in the above. The hydrocarbon group having an ether bond is preferably a group in which a portion of the carbon atoms of an optionally substituted linear or branched alkyl group have been substituted with oxygen atoms, more preferably a group in which a portion of the carbon atoms of a linear alkyl group have been substituted with oxygen atoms, and even more preferably a group in which a portion of the carbon atoms of a linear alkyl group having 1 to 5 carbon atoms have been substituted with oxygen atoms.

[0050] Specific examples of hydrocarbon groups having an ether bond are shown below. * indicates Ra 031 , Ra 032 and Ra 033 indicates the bond bonded to the carbon atom to which the

[0051] [ka]

[0052] In the formula (a0-1), Ra 00 Suitable examples of the acid-dissociable group include those represented by the following general formula (a0-r1-10).

[0053] [ka] [wherein Yaa is a carbon atom; Xaa is a group which, together with Yaa, forms a monocyclic alicyclic group; Ra 0311 and Ra 0321 are each independently a hydrogen atom or a linear or branched alkyl group which may have a substituent. 0331 is a hydrocarbon group having 1 to 5 carbon atoms and an ether bond.]

[0054] In the formula (a0-r1-10), the monocyclic alicyclic group formed by Xaa together with Yaa is preferably a group in which two or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, more preferably 5 or 6 carbon atoms, and even more preferably 5 carbon atoms. Specifically, cyclopentane and cyclohexane are more preferred, and cyclopentane is even more preferred.

[0055] The monocyclic alicyclic group formed by Xaa together with Yaa may have a substituent, such as a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group), or an alkyloxycarbonyl group.

[0056] In the formula (a0-r1-10), Ra 0311 and Ra 0321 is a hydrogen atom or a linear or branched alkyl group which may have a substituent. Ra 0311 and Ra 0321 The linear or branched alkyl group in is preferably a linear alkyl group, more preferably a linear alkyl group having 1 to 5 carbon atoms, further preferably a methyl group, an ethyl group, or an n-butyl group, and particularly preferably a methyl group or an ethyl group.

[0057] In the formula (a0-r1-10), Ra 0311 and Ra 0321 Among the above, is preferably a hydrogen atom or a linear alkyl group, more preferably a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, further preferably a hydrogen atom, a methyl group, an ethyl group, or an n-butyl group, and particularly preferably a hydrogen atom, a methyl group, or an ethyl group.

[0058] In the formula (a0-r1-10), it is preferable that the hydrocarbon group has 1 to 5 carbon atoms and an ether bond, and is a group in which a portion of a linear alkyl group having 1 to 5 carbon atoms is substituted with an oxygen atom. Specifically, the groups represented by the chemical formulas (a0-e-1) to (a0-e-6) above are preferred, with the groups represented by the chemical formulas (a0-e-1), (a0-e-2), (a0-e-4), or (a0-e-5) above being more preferred, and the group represented by the chemical formula (a0-e-1) being even more preferred.

[0059] Specific examples of the structural unit (a01) represented by the formula (a0-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0060] [ka]

[0061] [ka]

[0062] The structural unit (a01) contained in the component (A1) may be of one type, or may be of two or more types. The proportion of the structural unit (a01) in the component (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 %. When the proportion of the structural unit (a01) is at least as large as the lower limit of the aforementioned preferred range, sensitivity and lithography properties are further improved, while when it is at most the upper limit of the aforementioned preferred range, it becomes easier to achieve a balance with other structural units.

[0063] Other structural units The component (A1) may also include structural units other than the aforementioned structural unit (a01). Examples of other structural units include structural units (a1) containing an acid-decomposable group whose polarity increases when acted upon by acid (excluding structural unit (a01)); structural units (a2) containing a lactone-containing cyclic group, an —SO—-containing cyclic group, or a carbonate-containing cyclic group; structural units (a3) containing a polar group-containing aliphatic hydrocarbon group (excluding those corresponding to structural unit (a01), structural unit (a1), or structural unit (a2)); structural units (a4) containing an acid-non-dissociable aliphatic cyclic group; and structural units (a10) represented by general formula (a10-1) described below.

[0064] Regarding the structural unit (a1): In addition to the structural unit (a01), the component (A1) may further include a structural unit (a1) containing an acid-decomposable group whose polarity increases when acted upon by an acid.

[0065] 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 resists include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups," which are described below.

[0066] ·Acetal type acid dissociable group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable groups").

[0067] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Ra' 1 , Ra' 2may be bonded to any one of the following to form a ring.]

[0068] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 1 or Ra' 2 When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferred. Specific examples include linear or branched alkyl groups. More specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl and ethyl groups being more preferred, and methyl being particularly preferred.

[0069] In formula (a1-r-1), Ra' 3 Examples of the hydrocarbon group include a linear or branched alkyl 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, and an n-pentyl group. Of 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.

[0070] 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, with an isopropyl group being preferred.

[0071] Ra' 3When 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 is preferably one having 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0072] Ra' 3 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, further 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' 3Specific 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.

[0073] Ra' 3 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 chain 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, 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. 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.

[0074] Ra' 3 But Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0075] 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.

[0076] [ka] [In the formula, Ra' 4 ~Ra' 6 are each a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0077] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 The same can be mentioned. 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' 3 The same can be mentioned.

[0078] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably substituted or unsubstituted by the alkyl group. On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0079] [ka] [In formula (a1-r2-1), Ra' 10 Ra' represents a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. 11 Ra' 10 represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ya is bonded. 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 which forms an aliphatic cyclic group together with Yaa. Ra 104 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. 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.]

[0080] In the above formula (a1-r2-1), Ra' 10 is a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group.

[0081] Ra' 10The 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' 10 In the formula (I), the branched alkyl group is the above-mentioned Ra' 3 The same can be mentioned.

[0082] Ra' 10 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.

[0083] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which the carbon atom is bonded is represented by Ra' in formula (a1-r-1). 3 Among these, a monocyclic alicyclic hydrocarbon group is preferred, and specifically, a cyclopentyl group or a cyclohexyl group is more preferred, with a cyclopentyl group being even more preferred.

[0084] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). 3 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' 3 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 103In the 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 103 Among 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.

[0085] 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.

[0086] 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.

[0087] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 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.

[0088] 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, and a halogen atom.

[0089] 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 or a hydrogen atom. 12 and Ra' 13 In the formula, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned 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. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, a hydrogen atom or an alkyl group having 1 to 5 carbon atoms is preferred, an alkyl group having 1 to 5 carbon atoms is more preferred, a methyl group or an ethyl group is even more preferred, and a methyl group is 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.

[0090] 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.

[0091] Ra' 14 The 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.

[0092] 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, with an isopropyl group being preferred.

[0093] 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 is preferably one having 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0094] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon groups Ra' are the same as those in 14 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 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.

[0095] 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.

[0096] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0097] [ka]

[0098] [ka]

[0099] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0104] [ka]

[0105] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0106] [ka]

[0107] Tertiary alkyloxycarbonyl acid dissociating group: Among the polar groups, examples of the acid-dissociable group that protects the hydroxyl group include acid-dissociable groups represented by the following general formula (a1-r-3) (hereinafter, for convenience, may be referred to as "tertiary alkyloxycarbonyl acid-dissociable group").

[0108] [ka] [In the formula, Ra' 7 ~Ra' 9 are each alkyl groups.

[0109] In formula (a1-r-3), Ra' 7 ~Ra' 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0110] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent; a structural unit derived from acrylamide; a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least some of the hydrogen atoms in the hydroxyl groups are protected with a substituent containing the above-mentioned acid-decomposable group; and a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least some of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0111] Of the above, preferred structural units (a1) are structural units derived from acrylate esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. Preferred specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

[0112] [ka] [wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.] 1 is a divalent hydrocarbon group which may have an ether bond, and n a1 is 0 to 2, and Ra 1is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2). 1 is n a2 + monovalent hydrocarbon group, n a2 is 1 to 3, and Ra 2 is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-3).

[0113] In the formula (a1-1), the alkyl group of 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group of 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 of 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group of 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, with a fluorine atom being 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.

[0114] In the formula (a1-1), Va 1 The divalent hydrocarbon group which may have an ether bond is represented by Va in the formula (a0-1). 0 This is the same as the divalent hydrocarbon group which may have an ether bond in the above formula.

[0115] In the formula (a1-2), Wa 1 n in a2The monovalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in their structure, and groups that combine linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in their structure. The n a2 The +1 valence is preferably 2 to 4, more preferably 2 or 3.

[0116] Specific examples of the structural unit represented by formula (a1-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] The structural unit (a1) 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 (a1), the proportion of the structural unit (a1) in the component (A1) is preferably 1 to 50 mol %, more preferably 5 to 45 mol %, and even more preferably 5 to 30 mol %, based on the total amount of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least as large as the lower limit, a resist pattern can be easily obtained, and lithography properties such as sensitivity, resolution, roughness improvement, and EL margin can be improved. Furthermore, by ensuring that the proportion is at most the upper limit, a balance with other structural units can be achieved.

[0125] Regarding the structural unit (a2): The component (A1) may further include a structural unit (a2) that includes a lactone-containing cyclic group, an —SO 2 —-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.

[0126] 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).

[0127] [ka] [In the formula, 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.

[0128] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The 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 The halogen atom in is preferably a fluorine atom. Ra' 21 The halogenated alkyl group in the formula Ra' is 21Examples 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.

[0129] Ra' 21 In -COOR" and -OC(=O)R", 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. 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. 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). 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 a hydroxyalkyl group having 1 to 6 carbon atoms. 21 and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0130] 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.

[0131] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are listed below.

[0132] [ka]

[0133] [ka]

[0134] 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).

[0135] [ka] [In the formula, 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.

[0136] 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.

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] 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).

[0141] [ka] [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.

[0142] 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' 31 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 are similar to 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.

[0143] [ka]

[0144] 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).

[0145] [ka] [In the formula, 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 —SO—-containing cyclic group.

[0146] In the formula (a2-1), R is the same as defined above. 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.

[0147] In the formula (a2-1), Ya 21 The divalent linking group in the formula (a01-1) 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. 01 This is the same as the divalent hydrocarbon group exemplified in the explanation of

[0148] 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.

[0149] 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). Among these, lactone-containing cyclic groups are preferred, and groups represented by the general formula (a2-r-1), (a2-r-2) or (a2-r-6) are more preferred. Specifically, any of the 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, any of the groups represented by the chemical formulas (r-lc-2-1) to (r-lc-2-18), and (r-lc-6-1) are more preferred, and the group represented by the chemical formula (r-lc-2-1) is even more preferred.

[0150] 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 even more preferably 40 to 60 mol%. By ensuring that the proportion of the structural unit (a2) falls within the above preferred range, developer solubility can be appropriately ensured, making it easier to achieve the effects of the present invention.

[0151] Regarding the structural unit (a3): The component (A1) may further include a structural unit (a3) that includes a polar group-containing aliphatic hydrocarbon group.

[0152] Examples of the polar group include a hydroxyl group, a cyano group, a carboxyl group, and a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms, with a hydroxyl group being particularly preferred. Examples of aliphatic hydrocarbon groups include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms, and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected from the many groups proposed for use in resins for resist compositions for ArF excimer lasers.

[0153] When the cyclic group is a monocyclic group, it more preferably has 3 to 10 carbon atoms. Among these, structural units derived from acrylate esters containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the alkyl group's hydrogen atoms are substituted with fluorine atoms are more preferred. Examples of such monocyclic groups include groups in which two or more hydrogen atoms have been removed from a monocycloalkane. Specific examples include groups in which two or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane, cyclohexane, or cyclooctane. Among these monocyclic groups, groups in which two or more hydrogen atoms have been removed from cyclopentane and groups in which two or more hydrogen atoms have been removed from cyclohexane are industrially preferred.

[0154] When the cyclic group is a polycyclic group, the polycyclic group preferably has 7 to 30 carbon atoms. Among these, structural units derived from acrylate esters containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the alkyl group's hydrogen atoms are substituted with fluorine atoms are more preferred. Examples of such polycyclic groups include groups in which two or more hydrogen atoms have been removed from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specific examples include groups in which two or more hydrogen atoms have been removed from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane are industrially preferred.

[0155] There are no particular limitations on the structural unit (a3), and any structural unit can be used as long as it contains a polar group-containing aliphatic hydrocarbon group. As the structural unit (a3), a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and which contains a polar group-containing aliphatic hydrocarbon group is preferred. When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit (a3) is preferably a structural unit derived from a hydroxyethyl ester of acrylic acid. Furthermore, when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, preferred examples of the structural unit (a3) include structural units represented by the following formulas (a3-1), (a3-2), and (a3-3); and when the hydrocarbon group is a monocyclic group, preferred examples of the structural unit (a3) include structural units represented by formula (a3-4).

[0156] [ka] [In the formula, R is the same as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 0 to 5, and s is an integer of 1 to 3.]

[0157] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, the hydroxyl groups are preferably bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, the hydroxyl group is preferably bonded to the 3rd position of the adamantyl group. j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0158] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0159] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxyl group of the acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0160] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0161] The structural unit (a3) 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 (a3), the proportion of the structural unit (a3) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and even more preferably 5 to 25 mol%. By ensuring that the proportion of the structural unit (a3) is at least as great as the preferred lower limit, the effects that can be achieved by including the structural unit (a3) can be fully obtained due to the effects described above. By ensuring that the proportion of the structural unit (a3) is at most the preferred upper limit, a balance with other structural units can be achieved, and various lithography properties can be improved.

[0162] Regarding the structural unit (a4): The component (A1) may further include a structural unit (a4) that includes an acid-non-dissociable aliphatic cyclic group. The “acid-non-dissociable cyclic group” within the structural unit (a4) is a cyclic group that, when acid is generated in the resist composition upon exposure (when acid is generated from the component (B)), does not dissociate even when acted upon by the acid, and remains intact within the structural unit.

[0163] The structural unit (a4) is preferably, for example, a structural unit derived from an acrylate ester that contains an acid-non-dissociable aliphatic cyclic group. The cyclic group can be any of the many conventionally known resin components used in resist compositions for ArF excimer lasers, KrF excimer lasers (preferably ArF excimer lasers), and the like. The cyclic group is preferably at least one selected from the group consisting of a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group, in view of industrial availability, etc. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7).

[0164] [ka] [In the formula, R α is the same as above.]

[0165] The structural unit (a4) 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 (a4), the proportion of the structural unit (a4) relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 1 to 40 mol %, and more preferably 5 to 20 mol %. By ensuring that the proportion of the structural unit (a4) is at least as large as the preferred lower limit, the effects of including the structural unit (a4) can be fully achieved, while by ensuring that the proportion is at most the preferred upper limit, it becomes easier to achieve a balance with other structural units.

[0166] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0167] [ka] [In the formula, 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.] x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.]

[0168] In the formula (a10-1), 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 for 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 for R 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 from the viewpoint of industrial availability, more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

[0169] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0170] Optionally substituted divalent hydrocarbon groups: Ya x1 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.

[0171] Ya x1 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.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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. The halogen atom as the substituent is preferably a fluorine atom. 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-.

[0176] Ya x1 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 number of carbon atoms 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.

[0177] 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.

[0178] Divalent linking groups containing heteroatoms: Ya x1is 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 general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 22 -, 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. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, acyl, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the above-mentioned Ya x1 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. 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.

[0179] Among the above, Ya x1is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0180] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax1 Examples of the aromatic ring include a group in which 4n+1) hydrogen atoms have been removed. 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, even 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 aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in (n) is selected from aromatic compounds containing an aromatic ring which may have two or more substituents (for example, biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As examples, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred. ax1 A group obtained by removing (n +1) hydrogen atoms from benzene is more preferred. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0181] Wa x1The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include Ya x1 Examples of the substituent include the same as those exemplified as the substituent of the cyclic aliphatic hydrocarbon group in Wa. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0182] In the formula (a10-1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0183] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] [ka]

[0188] The structural unit (a10) 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 (a10), the proportion of the structural unit (a10) in the component (A1) is preferably 1 to 40 mol %, more preferably 1 to 30 mol %, and even more preferably 1 to 20 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at least as large as the lower limit of the above range, sensitivity can be further improved, while by ensuring that the proportion is at most the upper limit, it is easier to achieve a balance with other structural units.

[0189] The component (A1) contained in the resist composition may use either a single type of compound, or a combination of two or more types of compounds. In the resist composition of this embodiment, the component (A1) is a resin component that includes the structural unit (a01). Suitable examples of the component (A1) include polymeric compounds having the structural unit (a01) and the structural unit (a2). In this case, the proportion of the structural unit (a01) in the polymer compound is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the polymer compound. Furthermore, the proportion of the structural unit (a2) in the polymer compound is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the polymer compound.

[0190] The molar ratio of the structural unit (a01) to the structural unit (a2) in the polymer compound (structural unit (a01):structural unit (a2)) is preferably 2:8 to 8:2, more preferably 3:7 to 7:3, and even more preferably 4:6 to 6:4.

[0191] Specifically, the component (A1) is preferably a copolymer comprising a repeating structure of the structural unit (a01) and the structural unit (a2).

[0192] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of the component (A1) is less than or equal to the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is at least the preferred lower limit of this range, the compound exhibits good dry etching resistance and the cross-sectional shape of the resist pattern. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0193] The component (A1) may be used alone or in combination of two or more types. The proportion of the (A1) component in the (A) component is preferably 25 mass % or more, more preferably 50 mass % or more, and even more preferably 75 mass % or more, relative to the total mass of the (A) component, and may be 100 mass %. When the amount of the component (A1) is at least as large as the lower limit of this preferred range, it becomes easier to form a resist pattern that exhibits high sensitivity and excellent lithography properties.

[0194] About ingredient (A2) The resist composition of this embodiment may also use, as the component (A), a base component (hereafter referred to as “component (A2)”) that does not fall under the category of the component (A1) and whose solubility in a developer changes upon the action of an acid. There are no particular restrictions on the component (A2), and it can be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be used alone or in combination of two or more.

[0195] In the resist composition of this embodiment, the component (A) may use either a single type of compound, or a combination of two or more types of compounds. The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0196] <Acid generator component (B)> The resist composition of this embodiment contains an acid generator component (B) that generates an acid upon exposure. The component (B) contains a compound (B1) (hereinafter also referred to as "component (B1)") represented by the following general formula (b1-1):

[0197] ≪Compound (B1)≫ The compound (B1) is a compound represented by the following general formula (b1-1).

[0198] [ka] [In the formula, R b01 is a polycyclic hydrocarbon group having a hydroxy group. The polycyclic hydrocarbon group may have a substituent other than a hydroxy group. Y b01 is a divalent linking group containing an oxygen atom or a single bond. b01 is an alkylene group or a fluorinated alkylene group. b02 is a fluorine atom or a hydrogen atom; m is an integer of 1 or more; M m+ is an m-valent organic cation.

[0199] {anion part} In formula (b1-1), R b01 is a polycyclic hydrocarbon group having a hydroxy group. The polycyclic hydrocarbon group may be a polycyclic alicyclic hydrocarbon group or a polycyclic aromatic hydrocarbon group.

[0200] The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton.

[0201] Examples of polycyclic aromatic hydrocarbon groups include naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. The polycyclic aromatic hydrocarbon group may also be a fused ring group containing a fused ring formed by condensing an aliphatic hydrocarbon ring with an aromatic ring. Examples of the fused ring include a polycycloalkane having a bridged ring polycyclic skeleton to which one or more aromatic rings are fused. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring formed by condensing two or three aromatic rings with a bicycloalkane, and more preferably a group containing a fused ring formed by condensing two or three aromatic rings with a bicyclo[2.2.2]octane. R b01 Specific examples of the fused cyclic group in the formula (b1-1) include groups represented by the following formula (r-br-1) or (r-br-2). b01 indicates the bond bonded to

[0202] [ka]

[0203] In formula (b1-1), R b01Of the above, the polycyclic hydrocarbon group is preferably a polycyclic alicyclic hydrocarbon group, more preferably a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, still more preferably a group in which one or more hydrogen atoms have been removed from adamantane or norbornane, and particularly preferably a group in which one or more hydrogen atoms have been removed from adamantane.

[0204] In formula (b1-1), R b01 The number of hydroxy groups that the polycyclic hydrocarbon group has in the formula is preferably 1 to 5, more preferably 1 to 3, even more preferably 1 or 2, and particularly preferably 1.

[0205] In formula (b1-1), R b01 The polycyclic hydrocarbon group in may have a substituent other than a hydroxy group, and examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a carbonyl group, a nitro group, and an amino group.

[0206] In formula (b1-1), Y b01 is a divalent linking group containing an oxygen atom or a single bond. Y b01 is a divalent linking group containing an oxygen atom, b01 may contain atoms other than oxygen atoms, such as carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of such divalent linking groups containing an oxygen atom include linking groups represented by the following general formulae (y-al-1) to (y-al-7).

[0207] [ka] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a single bond or a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0208] V' 102The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0209] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, but is preferably a straight-chain alkylene group. V' 101 and V' 102 Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; 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-]. Also, V' 101 or V' 102 Some of the methylene groups in the alkylene group in the formula may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms.

[0210] Among the above, V' 101 is preferably a single bond. Also, among the above, V' 102 is preferably a single bond, a methylene group, or an ethylene group.

[0211] Y b01As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, the linking groups represented by the above general formulas (y-al-1) to (y-al-5) are more preferable, and the linking group represented by (y-al-1) is even more preferable.

[0212] In formula (b1-1), V b01 is an alkylene group or a fluorinated alkylene group. The alkylene group in the alkylene group or fluorinated alkylene group preferably has 1 to 9 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms. Furthermore, the alkylene group may be a linear alkylene group or a branched alkylene group, but is preferably a linear alkylene group. The alkylene group in the fluorinated alkylene group may have some or all of its hydrogen atoms substituted with fluorine atoms, and among these, the fluorinated alkylene group is preferably a group in which some of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.

[0213] R b02 is a fluorine atom or a hydrogen atom. V b01 and R b02 The total number of fluorine atoms contained in and is preferably 1 to 3, more preferably 1 or 2, and even more preferably 2.

[0214] V b01 and R b02 When the total number of fluorine atoms contained therein is 1 to 3, the sensitivity is further improved. When the total number of fluorine atoms is 1 or 2, the balance between the sensitivity and the DOF is better. When the total number of fluorine atoms is 2, the balance between the sensitivity and the DOF is better, and the in-plane uniformity (CDU) of the pattern dimension is also improved.

[0215] Specific examples of the anion moiety in the component (B1) are listed below: However, the anion moiety in the component (B1) is not limited to these specific examples.

[0216] [ka]

[0217] [ka]

[0218] {cation part} In the formula (b1-1), M m+ represents an organic cation having a valence of m. Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or greater.

[0219] Preferred cationic moieties ((M m+ ) 1 / m ) includes organic cations represented by the following general formulas (ca-1) to (ca-5), respectively.

[0220] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 R each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 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. 201 represents -C(=O)- or -C(=O)-O-. Y 201each independently represents an arylene group, an alkylene group, or an alkenylene group. x is 1 or 2. W 201 represents a (x+1)-valent linking group.

[0221] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212 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 201 ~R 207 , and R 211 ~R 212 The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 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, and groups represented by the following general formulae (ca-r-1) to (ca-r-7).

[0222] [ka] [In the formula, R' 201 are each independently a hydrogen atom, 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.

[0223] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0224] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201 Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0225] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0226] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0227] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly 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 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.

[0228] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the —SO—-containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0229] R' 201 Examples of the substituent in the cyclic group 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. As the halogen atom as a substituent, a fluorine atom is 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. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0230] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group 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. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include 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.

[0231] An optionally substituted chain alkenyl group: R' 201The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0232] R' 201 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above-mentioned R' 201 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0233] R' 201 In addition to those mentioned above, the optionally substituted cyclic group, the optionally substituted chain alkyl group, or the optionally substituted chain alkenyl group also includes the same as the acid-dissociable group represented by formula (a1-r-2) above as the optionally substituted cyclic group or the optionally substituted chain alkyl group.

[0234] Among them, R' 201 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), or an —SO2- containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4) is preferred.

[0235] In the above general formulas (ca-1) to (ca-5), R 201 ~R203 , R 206 ~R 207 , R 211 ~R 212 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 )-(applicable 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 benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0236] 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.

[0237] 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 the formula (I) 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 210As the optionally substituted SO2-containing cyclic group in the above, an "-SO2-containing polycyclic group" is preferred, and a group represented by the above general formula (a5-r-1) is more preferred.

[0238] Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the formula (I) is the same as R' 201 Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified above. Y 201 The alkylene group and alkenylene group in the formula (I) are the same as those in the formula (I) above. 201 Examples of the chain alkyl group and the chain alkenyl group include groups in which one hydrogen atom has been removed from the groups exemplified above as the chain alkyl group and the chain alkenyl group.

[0239] In the formula (ca-4), x is 1 or 2. W 201 is an (x+1)-valent, i.e., a divalent or trivalent linking group. W 201 The divalent linking group in the formula (a2-1) is preferably a divalent hydrocarbon group which may have a substituent. 21 Examples of the divalent hydrocarbon groups include those shown below, which may have a substituent. 201 The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred. W 201 The trivalent linking group in 201 Examples of the divalent linking group include a group in which one hydrogen atom has been removed from the divalent linking group shown in the formula (1), and a group in which the divalent linking group is further bonded to the divalent linking group shown in the formula (1). 201 The trivalent linking group in the formula (I) is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0240] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0241] [ka]

[0242] [ka]

[0243] [ka] [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.]

[0244] [ka]

[0245] [ka]

[0246] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 , and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the group

[0247] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0248] 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).

[0249] [ka]

[0250] Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0251] [ka]

[0252] Specific examples of suitable cations represented by the formula (ca-5) include cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0253] [ka]

[0254] Among the above, the cation part ((M m+ ) 1 / m ) is preferably a cation represented by general formula (ca-1).

[0255] Specific examples of suitable components (B1) within the resist composition of this embodiment are listed below.

[0256] [ka]

[0257] In the resist composition of this embodiment, the component (B1) may use either a single type, or a combination of two or more types. In the resist composition of this embodiment, the amount of the component (B1) relative to 100 parts by mass of the component (A1) is preferably less than 50 parts by mass, more preferably 1 to 40 parts by mass, and even more preferably 1 to 20 parts by mass. By ensuring that the amount of the component (B1) falls within this preferred range, sufficient pattern formation is achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is also favorable.

[0258] In the resist composition of this embodiment, the amount of the component (B1) relative to the entire amount of the component (B) is, for example, 50 mass % or more, preferably 70 mass % or more, and even more preferably 95 mass % or more, and may be 100 mass %.

[0259] ≪(B2) Component≫ The resist composition of this embodiment may also contain an acid generator component (hereafter referred to as "component (B2)") other than the above-mentioned component (B1), 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 bisaryl sulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzyl sulfonate-based acid generators, imino sulfonate-based acid generators, and disulfone-based acid generators.

[0260] Examples of onium salt acid generators include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)"). Note that component (b-1) does not include compounds that fall under the above-mentioned component (B1). That is, in the following general formula (b-1), V 101 and R102 Those having a total of 2 or 3 fluorine atoms are excluded.

[0261] [ka] [In the formula, R 101 and R 104 ~R 108 R each independently 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. 104 and R 105 R may be bonded to each other to form a ring structure. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 are each independently a single bond or an oxygen atom. 103 ~L 105 are each independently a single bond, —CO— or —SO2—; m is an integer of 1 or more; and M' m+ is an m-valent onium cation.

[0262] {anion part} Anion in component (b-1) In formula (b-1), R 101 represents an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0263] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0264] R 101 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0265] R 101 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0266] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0267] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof 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 which may be bonded to the alicyclic 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.

[0268] Also, R 101 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the —SO—-containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0269] R 101Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl 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. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0270] An optionally substituted chain alkyl group: R 101 The chain alkyl group 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. 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 decanyl 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. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. Specific examples include 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.

[0271] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0272] R 101 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0273] Among the above, R 101 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, preferred are a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), and an —SO2- containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4).

[0274] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 As for Y in the above formula (b1-1), b01 The same can be mentioned. Y 101 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferred, and the linking groups represented by the above formulas (y-al-1) to (y-al-5) are more preferred.

[0275] In formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in the formula (V) preferably have 1 to 4 carbon atoms. 101 The fluorinated alkylene group in 101 In particular, groups in which some or all of the hydrogen atoms of the alkylene group in the formula (I) are substituted with fluorine atoms are preferred. 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0276] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0277] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following formulae (an-1) to (an-3).

[0278] [ka] [In the formula, R” 101 R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-6), or a chain alkyl group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or an -SO2- containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively. 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0279] R” 101 , R” 102 and R” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the formula (b-1). 101 Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0280] R” 103 The aromatic cyclic group which may have a substituent in the formula (b-1) is R 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). 101 Examples of the substituents that may substitute the aromatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0281] R” 101 The chain alkyl group which may have a substituent in the formula (b-1) is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula. R” 103 The chain alkenyl group which may have a substituent is R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0282] Anion in component (b-2) In formula (b-2), R 104 , R 105 are each independently 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 is represented by R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 is preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in resist solvents. 104 , R 105In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 The same can be mentioned. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0283] Anion in component (b-3) In formula (b-3), R 106 ~R 108 are each independently 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 is represented by R 101 The same can be mentioned. In formula (b-3), L 103 ~L 105 are each independently a single bond, —CO— or —SO2—.

[0284] Among the above, the anion moiety of component (B) is preferably the anion in component (b-1). Among these, anions represented by any of the above general formulas (an-1) to (an-3) are more preferred, anions represented by either general formula (an-1) or (an-2) are even more preferred, and anions represented by general formula (an-2) are particularly preferred.

[0285] {cation part} In the formula (b-1), formula (b-2), and formula (b-3), M' m+is an m-valent onium cation, and is the same as M m+ The same can be mentioned.

[0286] In the resist composition of this embodiment, the component (B2) may be used either as a single type, or in combination of two or more types. When the resist composition of this embodiment contains the component (B2), the amount of the component (B2) in the resist composition relative to the entire component (B) is, for example, 50 mass% or less, more preferably 30 mass% or less, and even more preferably from 0 mass% to 5 mass%.

[0287] In the resist composition of this embodiment, the amount of the component (B) relative to 100 parts by mass of the component (A1) is preferably less than 50 parts by mass, more preferably 1 to 40 parts by mass, and even more preferably 1 to 20 parts by mass. By ensuring that the amount of the component (B1) falls within this preferred range, sufficient pattern formation is achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is also favorable.

[0288] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-described components (A) and (B). Examples of other components include the following components (D), (E), (F), and (S).

[0289] <Base component (D)> The resist composition of this embodiment may further contain a base component (component (D)) that traps the acid generated upon exposure (i.e., controls the diffusion of the acid). The component (D) acts as a quencher (acid diffusion controller) that traps the acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its acid diffusion controllability, and a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1). Among these, the photodegradable base (component (D1)) is preferred from the viewpoints of increasing sensitivity and improving DOF and CDU.

[0290] 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 compounds 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 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.

[0291] [ka] [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, or a chain alkenyl group which may have a substituent. 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.

[0292] {(d1-1) component} Anion part In formula (d1-1), Rd 1 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 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-like alkyl group which may have a substituent is preferred. Substituents 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 represented by each of the above general formulas (a2-r-1) to (a2-r-7), 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 above formulas (y-al-1) to (y-al-5). Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (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.

[0293] 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.

[0294] Preferred examples of the anion moiety of the component (d1-1) are shown below.

[0295] [ka]

[0296] 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-5), 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-1-70) being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0297] {(d1-2) component} Anion part 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 R' 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 2is 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, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. 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.

[0298] Preferred examples of the anion moiety of the component (d1-2) are shown below.

[0299] [ka]

[0300] 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.

[0301] {(d1-3) component} Anion part 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 1The same fluorinated alkyl groups as those mentioned above are more preferred.

[0302] 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 R' 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. 4 A 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.

[0303] 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.

[0304] Road 4 The cyclic group in the formula (I) is the same as the R' 201Examples 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.

[0305] 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 a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. 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.

[0306] Preferred examples of the anion moiety of the component (d1-3) are shown below.

[0307] [ka]

[0308] [ka]

[0309] 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.

[0310] 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. Of the above, the component (d1-1) is preferred as the component (D1).

[0311] When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, per 100 parts by mass of the component (A1). When the amount of the component (D1) is within this preferred range, particularly favorable lithography properties and resist pattern shape are more likely to be obtained.

[0312] 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.

[0313] Regarding component (D2) The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the component (D1) described above. 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 component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are particularly preferred. An 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 preferred, and tri-n-pentylamine or tri-n-octylamine is more preferred.

[0314] 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 is preferably one having 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.

[0315] 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.

[0316] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0317] The component (D2) may be used alone or in combination of two or more. Of the above, the component (D2) is preferably a trialkylamine having 5 to 10 carbon atoms, and more preferably tri-n-pentylamine or tri-n-octylamine.

[0318] When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the component (A1). When the amount of the component (D2) is within this preferred range, particularly good lithography properties and resist pattern shape are more likely to be obtained.

[0319] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing sensitivity degradation and improving the resist pattern shape and stability over time after exposure. Suitable organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic 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. In the resist composition of this embodiment, 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) is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A1).

[0320] <Fluorine additive component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as “component (F)”) in order to impart water repellency to the resist film or to improve 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 specifically, component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1). Examples of this polymer include: a polymer (homopolymer) consisting solely of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) with the structural unit (a1); a copolymer of the structural unit (f1) with a structural unit derived from acrylic acid or methacrylic acid and the structural unit (a1); and a copolymer of the structural unit (f1) with the structural unit (a4), with a copolymer of the structural unit (f1) with the structural unit (a4) being more preferred. Specifically, a suitable example is a copolymer of the structural unit (f1) with a structural unit represented by the above general formula (a4-5).

[0321] [ka] [wherein R is the same as defined above, and Rf 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.

[0322] In 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 formula (f1-1), Rf102 and Rf 103 The halogen atom in Rf is preferably a fluorine atom. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms in Rf include the same alkyl groups having 1 to 5 carbon atoms as those in 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. As the halogen atom, a fluorine atom is 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 formula (f1-1), nf 1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 0.

[0323] In 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, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, or -CH2-CH2-CF2-CF2-CF2-CF3.

[0324] 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 component has sufficient solubility in a resist solvent for use as a resist, and when the Mw is above the lower limit of this range, the resulting resist film has good water repellency. 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.

[0325] In the resist composition of this embodiment, the component (F) may be used alone, or in combination of two or more different compounds. 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 (A1).

[0326] <Organic solvent component (S)> 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 is capable of dissolving the individual components used and forming a homogeneous solution, and any solvent that is appropriately selected from among those known to be conventionally used as solvents for chemically amplified resist compositions can be used. Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; and compounds having an ether bond such as monoalkyl ethers or monophenyl ethers of the above polyhydric alcohols or compounds having an ester bond, such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether. Examples of suitable solvents include derivatives of polyhydric alcohols (among which, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, the component (S) may be used either alone or as a mixed solvent of two or more different solvents. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0327] A mixed solvent of PGMEA and a polar solvent is also preferred as component (S). The blending ratio (mass ratio) may be determined appropriately taking into consideration the compatibility of PGMEA with the polar solvent, but 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 2:8 to 8:2. 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. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone, in which the mass ratio of the former to the latter is 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 %.

[0328] 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.

[0329] The resist composition of this embodiment may be prepared by dissolving the resist material in component (S) and then removing impurities using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of such polyimide porous films and polyamideimide porous films include those described in JP 2016-155121 A.

[0330] The resist composition of this embodiment described above contains a resin component (A1) having the structural unit (a01) described above, and a compound (B1). The structural unit (a01) has an acid-dissociable group represented by general formula (a0-r1-1) at the end of its side chain. Because this acid-dissociable group contains a hydrocarbon group with a polar ether bond, the acid-dissociable group is easily dissociated by exposure when forming a resist pattern. This enhances reactivity. On the other hand, compound (B1) has a polycyclic hydrocarbon group with a hydroxy group in the anion moiety, and since compound (B1) has a hydroxy group in the anion moiety, the diffusibility of the acid is appropriately suppressed. Therefore, it is presumed that the resist composition of this embodiment, which uses a resin component (A1) having a structural unit (a01) that includes an acid-dissociable group of a specific structure in combination with a compound (B1) having a specific structure, can achieve high sensitivity and also exhibit excellent depth of focus (DOF) characteristics.

[0331] (Method for 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 according to the first aspect of the present invention, 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.

[0332] 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 60 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 60 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.

[0333] 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. In this manner, a resist pattern can be formed.

[0334] 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. The support may also be a substrate as described above on which an inorganic and / or organic film is provided. Examples of inorganic films include inorganic anti-reflective coatings (inorganic BARCs). Examples of organic films include organic anti-reflective coatings (organic BARCs) and organic films such as lower organic films in multilayer resist methods. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the lower organic film is patterned using the resist pattern formed on the upper resist film as a mask, and it is said to be able to form patterns with a high aspect ratio. In other words, with the multilayer resist method, the required thickness can be ensured by the lower organic film, so the resist film can be made thinner and fine patterns with a high aspect ratio can be formed. Multilayer resist methods are basically divided into a two-layer structure consisting of an upper resist film and a lower organic film (two-layer resist method), and a three-layer structure consisting of three or more layers with one or more intermediate layers (such as a metal thin film) between the upper resist film and the lower organic film (three-layer resist method).

[0335] 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-ray, soft X-ray, etc. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB, or EUV.

[0336] 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. Specific examples of the fluorine-based inert liquid include liquids containing as a main component a fluorine-based compound such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, or C5H3F7, and preferably have a boiling point of 70 to 180° C., more preferably 80 to 160° C. If the fluorine-based inert liquid has a boiling point within the above range, it is preferable because the medium used for immersion can be removed simply and easily after exposure is completed. As the fluorine-based inert liquid, particularly preferred are perfluoroalkyl compounds in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms, specifically perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, the perfluoroalkyl ether compound may include perfluoro(2-butyl-tetrahydrofuran) (boiling point: 102°C), and the perfluoroalkylamine compound may include perfluorotributylamine (boiling point: 174°C). As the liquid immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, and the like.

[0337] 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 in their structure. Ester-based solvents are organic solvents that contain CC(=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, and the halogen atoms are preferably fluorine atoms. 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.

[0338] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0339] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl ether ... Dibutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate Examples of the ester solvent include butyl acetate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester solvent.

[0340] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0341] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, but examples include ionic or nonionic fluorine-based and / or silicon-based surfactants. Nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is added, the amount added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0342] 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).

[0343] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be appropriately selected from the organic solvents listed above as organic solvents used in the organic developer, and can be one that does not easily dissolve the resist pattern. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one solvent selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Of these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used alone or in combination of two or more. They may also be used in combination with other organic solvents or water. However, taking into consideration the development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on the total amount of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants include those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse liquid.

[0344] 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).

[0345] According to the resist pattern forming method of the present embodiment described above, the resist composition according to the above-described embodiment is used, so that a resist pattern with high sensitivity and excellent DOF characteristics can be formed. Furthermore, the resist pattern forming method of this embodiment is a useful method, particularly in solvent development processes, because the resist composition according to the above-described embodiment has excellent acid diffusion controllability. [Example]

[0346] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0347] <Production Example of Monomer (a01)> With reference to the synthesis examples described in paragraphs 0087 and 0090 of WO 2013 / 042694, synthesis was carried out using methyl 2,2-dimethyl-3-methoxypropionate and the like as raw materials to obtain the target monomer (m01), i.e., 1-(2'-methoxy-1',1'-dimethylethyl)cyclopentan-1-yl methacrylate, which has the following NMR characteristics:

[0348] [ka]

[0349] The resulting monomer (m01) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR(CDCl3)δ(ppm)=6.00(m,1H),5.47(m,1H),3.10(s,3H),3.08(s,2H),2.2 0-2.12(m,2H),2.05-1.95(m,4H),1.93(t,3H),1.60-1.50(m,2H),1.02(s,6H).

[0350] <Example of manufacturing base component (polymer compound)> A separable flask equipped with a thermometer, reflux condenser, and nitrogen inlet tube was charged with 17.90 g of methyl ethyl ketone (MEK) and heated to 80 °C. A solution of 17.22 g of monomer (m01), 15.00 g of monomer (m21), and 1.41 g of dimethyl azobisisobutyrate (V-601) as a polymerization initiator dissolved in 57.30 g of MEK was added dropwise over 4 hours under a nitrogen atmosphere. After the addition was complete, the reaction mixture was heated and stirred for 1 hour, after which the mixture was cooled to room temperature. The resulting polymerization mixture was added dropwise to a large amount of n-heptane to precipitate the polymer. The precipitated white powder was filtered and dried to obtain 23.30 g of the target polymer compound (A1-1).

[0351] [ka]

[0352] The resulting polymer compound (A1-1) had a weight average molecular weight (Mw) of 9900 in terms of standard polystyrene, as determined by GPC measurement, and a molecular weight dispersity (Mw / Mn) of 1.72. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0353] <Synthesis Examples 2 to 4> Polymer compounds (A1-2), (A2-1) and (A2-2) having the composition ratios shown in Table 1 were synthesized in the same manner as in Synthesis Example 1 using the compounds shown below. The obtained polymer compound was 13 The copolymer composition ratio of the polymer compound (the proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR, and the weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) calculated in terms of standard polystyrene determined by GPC measurement are also shown in Table 1.

[0354] [ka]

[0355] [ka]

[0356] [Table 1]

[0357] <Preparation of Resist Composition> (Examples 1 to 5, Comparative Examples 1 to 3) The components shown in Table 2 were mixed and dissolved to prepare the resist compositions of the respective examples.

[0358] [Table 2]

[0359] In Table 2, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass). (A1)-1, (A1)-2: The above polymer compounds (A1-1) and (A1-2). (A2)-1, (A2)-2: the above polymer compounds (A2-1), (A2-2). (B1)-1, (B1)-2: Acid generators consisting of compounds represented by the following chemical formulas (B1-1) and (B1-2), respectively. (B2)-1: An acid generator comprising a compound represented by the following chemical formula (B2-1).

[0360] [ka]

[0361] (D1)-1: An acid diffusion controller comprising a compound represented by the following chemical formula (D1-1). (D2)-1: Tri-n-pentylamine

[0362] [ka]

[0363] (F)-1: Fluorine-containing polymer compound represented by the following chemical formula (F-1): Weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 11,800, and molecular weight dispersity (Mw / Mn) is 1.61. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone in a mass ratio of 45 / 30 / 25.

[0364] [ka]

[0365] <Formation of Resist Pattern> An organic anti-reflective coating composition "ARC95" (trade name, manufactured by Brewer Science) was applied to a 12-inch silicon wafer using a spinner to form an organic anti-reflective coating with a thickness of 95 nm, followed by an inorganic anti-reflective coating. Each resist composition of each example was applied onto the inorganic anti-reflective coating using a spinner, and then pre-baked (PAB) on a hot plate at 120°C for 60 seconds, followed by drying to form a resist film with a thickness of 80 nm. Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (LITHO-04OV) using an ArF immersion exposure tool 1900Gi (manufactured by ASML; NA (numerical aperture) = 1.35, C-Quad (0.97 / 0.78) with TE-Polarization, immersion medium: water). After that, a post-exposure bake (PEB) treatment was performed for 60 seconds at each temperature shown in Table 3. Next, the film was subjected to solvent development with butyl acetate at 23° C. for 31 seconds, and then shaken off and dried. As a result, in all examples, a contact hole pattern (hereinafter referred to as a "CH pattern") was formed in which holes with a diameter of 45 nm were arranged at equal intervals (pitch of 300 nm).

[0366] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (mJ / cm) for forming a CH pattern of the target size by the above <Formation of resist pattern> 2 This is called "Eop (mJ / cm 2 )" are shown in Table 3.

[0367] [Evaluation of depth of focus (DOF)] The optimum exposure dose (Eop (mJ / cm)) for forming a CH pattern in resist pattern formation 2 )), and shifting the focus up and down as appropriate, a CH pattern was formed in the same manner as in <Formation of Resist Pattern> above. At this time, the depth of focus (DOF, unit: nm) at which the CH pattern could be formed within a dimensional change rate range of the target dimension ±5% (i.e., 42.75 to 47.25 nm) was determined. This is shown as "DOF (nm)" in Table 3.

[0368] [Evaluation of Pattern Dimension Uniformity (CDU)] The CH pattern formed by the above <Formation of Resist Pattern> was observed from above using a length measurement SEM (scanning electron microscope, accelerating voltage 300V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation), and the hole diameters (nm) of 40 holes in the CH pattern were measured. From the measurement results, a triple value (3σ) of the standard deviation (σ) was calculated. This is shown in Table 3 as "CDU (nm)". The smaller the value of 3σ determined in this way, the higher the dimension (CD) uniformity of the holes formed in the resist film.

[0369] [Table 3]

[0370] As shown in Table 3, it was confirmed that the resist compositions of the examples were able to form resist patterns that were superior in both sensitivity and DOF compared to the resist compositions of the comparative examples. In addition, the resist compositions of the examples have a pattern dimension uniformity (CDU) of 100%. It was confirmed that a good resist pattern could be formed.

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, a resin component (A1) 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 resin component (A1) has a structural unit (a01) represented by the following general formula (a0-1): The resist composition, wherein the acid generator component (B) contains a compound (B1) represented by the following general formula (b1-1): 【Chemical 1】 [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０ is a divalent hydrocarbon group which may have an ether bond. ａ０ is an integer from 0 to 2. ００ represents an acid-dissociable group represented by the general formula (a0-r1-10). Yaa represents a carbon atom. Xaa represents a group which, together with Yaa, forms a monocyclic alicyclic group. Ra 0311 represents a linear or branched alkyl group which may have a substituent. Ra 0321 represents a hydrogen atom, or a linear or branched alkyl group which may have a substituent. Ra 0331 represents a hydrocarbon group having 1 to 5 carbon atoms and an ether bond. * represents a bond.] 【Chemistry 2】 [In the formula, R ｂ０１ is a polycyclic hydrocarbon group having a hydroxy group. The polycyclic hydrocarbon group may have a substituent other than a hydroxy group. ｂ０１ is a divalent linking group containing an oxygen atom or a single bond. ｂ０１ is an alkylene group or a fluorinated alkylene group. ｂ０２ is a fluorine atom or a hydrogen atom; m is an integer of 1 or more; M ｍ＋ is an m-valent organic cation.

2. In the general formula (b1-1), V ｂ０１ and R ｂ０２ 2. The resist composition according to claim 1, wherein the total number of fluorine atoms contained in

3. 3. The resist composition according to claim 1, wherein the proportion of the structural unit (a01) within the resin component (A1) is 40 to 60 mol %, relative to the total (100 mol %) of all structural units constituting the resin component (A1).

4. 4. The resist composition according to claim 1, wherein the content of the compound (B1) is 1 to 20 parts by mass relative to 100 parts by mass of the resin component (A1).

5. 5. The resist composition according to claim 1, further comprising a photodegradable base (D1) that controls diffusion of the acid generated from the acid generator component (B) upon exposure.

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

7. 7. The method for forming a resist pattern according to claim 6, wherein in the step of exposing the resist film, the resist film is subjected to immersion exposure.

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