Resist composition, resist pattern forming method, compound and polymer compound

Abstract

To provide a resist composition, etc. which enables achieving higher sensitivity and have improved lithographic characteristics such as LWR and EL.SOLUTION: Provided is a resist composition which generates an acid upon light exposure and changes its solubility in a developer by the action of an acid, comprising a resin component (A1) which changes its solubility in a developer by the action of an acid. The resin component (A1) has a constituent unit (a0) derived from a compound represented by the following general formula (a0-m0). [W0 represents a polymerizable group-containing group; Y0 represents a single bond or a divalent linking group; and R01 represents an arylene group, an alkylene group or an alkenylene group, where one or more of R01-R03 have at least one iodine atom as a substituent.]SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resist composition, a method for forming a resist pattern, a compound, and a polymer compound.

Background Art

[0002] In recent years, in the production of semiconductor devices and liquid crystal display devices, pattern miniaturization has been rapidly progressing due to the advancement of lithography technology. As a miniaturization technique, generally, the wavelength of the exposure light source is shortened (energy is increased).

[0003] Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition containing a base material component whose solubility in a developer changes by the action of an acid and an acid generator component that generates an acid upon exposure has been conventionally used.

[0004] In a chemically amplified resist composition, generally, a resin having a plurality of constitutional units is used as the base material component in order to improve lithography characteristics and the like. In addition, in the formation of a resist pattern, the behavior of the acid generated from the acid generator component by exposure is regarded as one factor that greatly affects lithography characteristics. On the other hand, it has been proposed to use an acid diffusion controller that controls the diffusion of the acid generated from the acid generator component by exposure together with the acid generator component.

[0005] For example, Patent Document 1 discloses a resist composition that employs a polymer compound having a constitutional unit with a specific structure, and a sulfonium salt as an acid generator and an acid diffusion controller, respectively.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] As the miniaturization of resist patterns progresses, for example, in lithography using EUV or EB, the formation of fine patterns with a size of several tens of nm is targeted. Along with such miniaturization of resist patterns, it has become an issue to improve both sensitivity and lithography characteristics such as LWR and exposure latitude (EL) without trading them off with each other.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resist composition capable of achieving high sensitivity and improving lithography characteristics such as LWR and EL, a method for forming a resist pattern using the resist composition, a polymer compound that can be used in the resist composition, and a compound that can be used for synthesizing the polymer compound.

MEANS FOR SOLVING THE PROBLEMS

[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 by the action of the acid, containing a resin component (A1) whose solubility in a developer changes by the action of the acid, The resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m0), and is a resist composition that generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, contains a resin component (A1) whose solubility in a developer changes by the action of the acid, and the resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m0).

[0010]

CHEMICAL FORMULA

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

[0012] A third aspect of the present invention is a compound represented by the following general formula (a0-m0).

[0013]

Chemical formula

[0014] A fourth aspect of the present invention is a polymer compound containing the compound according to the third aspect.

Advantages of the Invention

[0015] According to the present invention, it is possible to provide a composition with improved sensitivity and improved lithography characteristics such as LWR and EL, a resist pattern forming method using the resist composition, a polymer compound that can be used in the resist composition, and a compound that can be used in the synthesis of the polymer compound.

Modes for Carrying Out the Invention

[0016] In this specification and the claims, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. that does not have aromaticity. "Alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group. "Alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. "Halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. "Constituent unit" means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer). When it is described as "may have a substituent", it includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) with a divalent group. "Exposure" is a concept that includes all irradiations of radiation.

[0017] The "acid-decomposable group" is a group having acid-decomposability such that at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxy group, an amino group, a sulfo group (-SO3H), etc. More specifically, examples of the acid-decomposable group include a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0018] The "acid-dissociable group" refers to both (i) a group having acid-dissociability such that the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which, after a part of the bonds are cleaved by the action of an acid, a decarboxylation reaction further occurs, whereby the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved. The acid-dissociable group constituting the acid-decomposable group needs to be a group having a lower polarity than the polar group generated by the dissociation of the acid-dissociable group. Thereby, when the acid-dissociable group is dissociated by the action of an acid, a polar group having a higher polarity than the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the whole of the component (A1) increases. By the increase in polarity, relatively, the solubility in the developer changes, and when the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

[0019] "Base material component" refers to an organic compound having film-forming ability. The organic compounds used as base material components are roughly classified into non-polymers and polymers. As non-polymers, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, in the case of "low molecular compound", it refers to a non-polymer having a molecular weight of 500 or more and less than 4000. As polymers, those having a molecular weight of 1000 or more are usually used. Hereinafter, in the case of "resin", "high molecular compound" or "polymer", it refers to a polymer having a molecular weight of 1000 or more. As the molecular weight of the polymer, the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography) shall be used.

[0020] "Derived structural unit" means a structural unit formed by the cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. The hydrogen atom bonded to the α-position carbon atom of "acrylic ester" may be substituted with a substituent. The substituent (R αx ) is an atom or group other than a hydrogen atom. Further, it shall also include itaconic acid diesters in which the substituent (R αx ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R αx ) is substituted with a hydroxyalkyl group or a group obtained by modifying the hydroxyl group thereof. In addition, the α-position carbon atom of acrylic ester means, unless otherwise specified, the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, the acrylic ester in which the hydrogen atom bonded to the α-position carbon atom is substituted with a substituent may be referred to as an α-substituted acrylic ester.

[0021] The term "derivative" refers to a concept that includes compounds in which the hydrogen atom at the α-position of the target compound is replaced by another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound, in which the hydrogen atom at the α-position may be replaced by a substituent, is replaced by an organic group; those in which a substituent other than a hydroxyl group is bonded to the target compound in which the hydrogen atom at the α-position may be replaced by a substituent, and the like. Here, the α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. Examples of the substituent that replaces the hydrogen atom at the α-position of hydroxystyrene include R αx the same as those described above.

[0022] In this specification and the claims of this patent, depending on the structure represented by the chemical formula, there may be asymmetric carbons and enantiomers or diastereomers may exist. In that case, those isomers are represented by one chemical formula. Those isomers may be used alone or as a mixture.

[0023] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility in a developer changes by the action of the acid. Such a resist composition contains a base material component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes by the action of an acid. Component (A) includes a resin component ((A1) component) having a structural unit (a0) described later. In the resist composition of this embodiment, the solubility of this (A1) component in a developer changes by the action of an acid. This (A1) component may generate an acid upon exposure, or may trap the acid generated upon exposure (that is, control the diffusion of the acid).

[0024] In the resist composition of this embodiment, component (A) may generate an acid upon exposure, or an additive component blended separately from component (A) may generate an acid upon exposure. Specifically, the resist composition of this embodiment may further contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as "component (B)"); (2) component (A) may be a component that generates an acid upon exposure; or (3) component (A) may be a component that generates an acid upon exposure and further contains component (B). That is, in the cases of (2) and (3) above, component (A) becomes a "base material component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid". When component (A) is a base material component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, it is preferable that component (A1) is a resin that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid. As such a resin, a polymer compound having a structural unit that generates an acid upon exposure can be used. As the structural unit that generates an acid upon exposure, structural unit (a5) described later may be used.

[0025] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, in the exposed portion of the resist film, for example, an acid is generated from component (B), and the solubility of component (A) in the developer changes due to the action of the acid. On the other hand, in the unexposed portion of the resist film, the solubility of component (A) in the developer does not change. Therefore, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, when the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and when the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0026] The resist composition of this embodiment may be a positive type resist composition or a negative type resist composition. Further, the resist composition of this embodiment may be for an alkali development process that uses an alkali developer for the development treatment during resist pattern formation, or may be for a solvent development process that uses a developer containing an organic solvent (organic-based developer) for the development treatment.

[0027] <Base material component (A)> In the resist composition of the present embodiment, as the component (A), it is preferable to use a resin component (A1) (hereinafter also referred to as “component (A1)”) whose solubility in a developer changes by the action of an acid. By using the component (A1), since the polarity of the base material component changes before and after exposure, good development contrast can be obtained not only in an alkali development process but also in a solvent development process. As the component (A), other high molecular compounds and / or low molecular compounds may be used in combination with the component (A1).

[0028] In the resist composition of the present embodiment, the component (A) may be used alone or in combination of two or more.

[0029] ·Regarding the component (A1) The component (A1) is a resin component whose solubility in a developer changes by the action of an acid, and has a structural unit (a0) derived from a compound represented by the following general formula (a0-m0). As the component (A1), in addition to the structural unit (a0), it may have other structural units as necessary.

[0030] ≪Structural unit (a0)≫ The structural unit (a0) is a structural unit derived from a compound represented by the following general formula (a0-m0) (hereinafter also referred to as “compound (a0-m0)”).

Chemical formula

[0031] {Cationic part} In the formula (a0-m0), the "polymerizable group" in the polymerizable group-containing group of W 0 is a group that enables a compound having a polymerizable group to polymerize by radical polymerization or the like, and refers to a group containing a multiple bond between carbon atoms such as an ethylenic double bond. Examples of the polymerizable group include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, a trifluoromethylacryloyl group, a nonafluorobutylacryloyl group, a vinyl ether group, a fluorine-containing vinyl ether group, an allyl ether group, a fluorine-containing allyl ether group, a styryl group, a vinylnaphthyl group, a fluorine-containing styryl group, a fluorine-containing vinylnaphthyl group, a norbornyl group, a fluorine-containing norbornyl group, a silyl group, a maleimide group, and the like.

[0032] The polymerizable group-containing group may be a group composed only of a polymerizable group, or a group composed of a polymerizable group and another group other than the polymerizable group. Examples of the other group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. Examples of the polymerizable group-containing group include a group represented by the formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 -. In the above formula, R X11 , R X12 and R X13 each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0represents a single bond or a divalent linking group. Ya x0 Examples of the divalent linking group in Ya include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. x0 Examples of the divalent linking group in Ya include an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an ether bond (-O-), a linear or branched alkylene group, or a combination thereof. x0 A single bond, an ester bond (-C(=O)-O-), or an oxycarbonyl group (-O-C(=O)-) is preferred.

[0033] In the formula (a0 - m0), Y 0 Examples of the divalent linking group in Ya are not particularly limited, but preferred examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like.

[0034] ·Divalent hydrocarbon group which may have a substituent: The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0035] ··Aliphatic hydrocarbon group The aliphatic hydrocarbon group means a hydrocarbon group having no 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, or an aliphatic hydrocarbon group containing a ring in its structure, and the like.

[0036] ···Linear or branched aliphatic hydrocarbon group The number of carbon atoms of the linear aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

[0037] The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, and the like.

[0038] ··· an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms 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 linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, and the like.

[0039] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and the like. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferred. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferred, and a methoxy group or an ethoxy group is even more preferred. As the halogen atom as the substituent, a fluorine atom or an iodine atom is preferable, and an iodine atom is more preferable. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are 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 hetero atom. As the substituent containing a hetero atom, -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O- are preferable.

[0040] ·· Aromatic hydrocarbon group The aromatic hydrocarbon group 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, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the 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; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms, and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, and the like. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, and the like. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0041] In the aromatic hydrocarbon group, the hydrogen atoms possessed by the aromatic hydrocarbon group may be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of the substituents include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom possessed by the cyclic aliphatic hydrocarbon group.

[0042] · Divalent linking group containing a heteroatom: Examples of the divalent linking group containing a heteroatom include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), -S-, -S(=O)2-, -S(=O)2-O-, general formula -Y 21 -O-Y22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 -represents a group [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 1 to 3.], etc. are exemplified. When the divalent linking group containing the hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H thereof may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. General formula -Y 21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 - Among them, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group are the same as those described above. Y 21 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22As for this, a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. 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 1 to 3, preferably 1 or 2, and more preferably 1. That is, the formula -[Y 21 -C(=O)-O] m” -Y 22 As the group represented by -, the group represented by the formula -Y 21 -C(=O)-O-Y 22 - is particularly preferable. Among them, the group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ - is preferable. 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, still 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, still more preferably 1 or 2, and most preferably 1.

[0043] Y 0 As for this, a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group which may have a substituent, an arylene group which may have a substituent, or a combination thereof is preferable, a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], or a combination of an arylene group which may have a substituent and an ester bond [-C(=O)-O-, -O-C(=O)-] is more preferable, and a single bond, or a combination of an arylene group which may have a substituent and an ester bond [-C(=O)-O-, -O-C(=O)-] is still more preferable.

[0044] In the formula (a0-m0), R 01Examples of the arylene group in [compound name] include unsubstituted arylene groups having 6 to 20 carbon atoms, with a phenylene group or a naphthylene group being preferred. Examples of the alkylene group include linear or cyclic alkylene groups, preferably those having 1 to 30 carbon atoms. The alkenylene group preferably has 2 to 10 carbon atoms. Said R 01 The arylene group, alkylene group, or alkenylene group in [compound name] may or may not have a substituent. Examples of the substituent include, for example, 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 general formulas (ca-r-1) to (ca-r-7) described later.

[0045] In the formula (a0-m0), R 02 and R 03 Examples of the aryl group in [compound name] include unsubstituted aryl groups having 6 to 20 carbon atoms, with a phenyl group or a naphthyl group being preferred. Examples of the alkyl group include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. The alkenyl group preferably has 2 to 10 carbon atoms. Alternatively, R 02 and R 03 may be mutually bonded to the benzene ring in the formula to form a ring together with a sulfur atom (S + ). However, one or more of R 01 to R 03 have at least one iodine atom as a substituent. Among them, R 01 preferably has at least one iodine atom, and more preferably has one iodine atom. Said R 02 and R 03 The aryl group, alkyl group, or alkenyl group in [compound name] may or may not have a substituent. Examples of the substituent include, for example, the same ones as the substituents in the above R 01 .

[0046] The structural unit (a0) is preferably a structural unit derived from a compound represented by the following general formula (a0-m1). [Chemical formula] [In the formula, W 0 is a polymerizable group-containing group. Y 0 is a single bond or a divalent linking group. Ar 01 ~Ar 03 are each independently an aromatic ring which may have a substituent. However, one or more of Ar 01 ~Ar 03 have at least one iodine atom. The aromatic rings in Ar 01 ~Ar 03 may each have a substituent other than iodine. Ar 02 and Ar 03 may be bonded to each other to form a ring together with the sulfur atom in the formula. X - is a counter anion.]

[0047] W 0 , Y 0 and X - in the formula (a0-m1) are the same as those in the general formula (a0-m0) respectively.

[0048] Ar 01 ~Ar 03 in the general formula (a0-m1) are each independently an 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 of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the 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 a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Ar 01 ~Ar 03 Among these, the aromatic ring in is preferably a benzene ring, a naphthalene ring or an anthracene ring, more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring.

[0049] The Ar 01 ~Ar 03 At least one of Ar 01 Preferably, has at least one iodine atom, more preferably has one iodine atom.

[0050] Ar 01 ~Ar 03 The aromatic rings in may or may not have a substituent other than iodine. The substituent other than iodine may be any of the above-mentioned R 01 The same can be mentioned. Ar 02 and Ar 03 may or may not be bonded to each other to form a ring together with the sulfur atom in the formula.

[0051] Specific examples of the cation moiety of the compound (a0-m0) include, but are not limited to, the following.

[0052] [ka]

[0053] [ka]

[0054] [Chemistry]

[0055] [Chemistry]

[0056] [Chemistry]

[0057] {Anion part} The above X - is a counter anion. When the above compound (a0-m0) is an acid generator, X - As the counter anion in, an anion selected from the group consisting of the anion parts of the compounds represented by the following general formulas (b-1) to (b-3) is preferable, and among them, the anion of the anion part of the compound represented by the following general formula (b-1) is more preferable. When the above compound (a0-m0) is an acid diffusion inhibitor, X - As the counter anion in, an anion selected from the group consisting of the anion parts of the compounds represented by (d1-1) to (d1-3) is preferable, and among them, the anion of the anion part of the compound represented by the following general formula (d1-1) is more preferable.

[0058] Specific examples of the anion part of the compound (a0-m0) are given below, but are not limited thereto.

[0059] [Chemistry]

[0060] Specific examples of the compound (a0-m0) are given below, but are not limited thereto.

[0061] [Chemistry]

[0062]

Chem.

[0063]

Chem.

[0064]

Chem.

[0065] As the compound (a0-m0), those selected from the group consisting of the compounds represented by the formulas (a0-mb-1) to (a0-mb-12) and (a0-md-1) to (a0-md-13) are preferable. Alternatively, since the sensitivity is more likely to be improved, those selected from the group consisting of the compounds represented by the formulas (a0-mb-3) to (a0-mb-8), (a0-mb-11), (a0-mb-12), (a0-md-3) to (a0-md-8), and (a0-md-11) to (a0-md-13) are preferable, and those selected from the group consisting of the compounds represented by the formulas (a0-mb-4), (a0-mb-5), (a0-mb-8), (a0-mb-11), (a0-md-3), (a0-md-4), (a0-md-6) to (a0-md-8), (a0-md-12), and (a0-md-13) are more preferable. Alternatively, since roughness is more likely to be reduced, those selected from the group consisting of the compounds represented by the formulas (a0-mb-2) to (a0-mb-8), (a0-mb-10) to (a0-mb-12), (a0-md-4), (a0-md-6) to (a0-md-8), (a0-md-11), and (a0-md-13) are preferred. Those selected from the group consisting of the compounds represented by the formulas (a0-mb-3), (a0-mb-4), (a0-mb-6) to (a0-mb-8), (a0-mb-12), (a0-md-7), and (a0-md-8) are more preferred. The compounds represented by the formulas (a0-mb-4), (a0-mb-6), and (a0-mb-7) are even more preferred. Alternatively, since the decrease in EL is more likely to be suppressed, those selected from the group consisting of the compounds represented by the formulas (a0-mb-2) to (a0-mb-12), (a0-md-6), and (a0-md-11) are preferred. Those selected from the group consisting of the compounds represented by the formulas (a0-mb-2) to (a0-mb-4), (a0-mb-6), (a0-mb-7), (a0-mb-10), and (a0-mb-11) are more preferred. Alternatively, from the viewpoint of achieving both high sensitivity, roughness reduction, and suppression of EL decrease, those selected from the group consisting of the compounds represented by the formulas (a0-mb-3) to (a0-mb-6) and (a0-mb-8) are preferred, and the compound represented by (a0-mb-4) is more preferred.

[0066] The constitutional unit (a0) contained in the component (A1) may be one kind or two or more kinds.

[0067] As the ratio of the constitutional unit (a0) in the component (A1), 0.5 to 35 mol% is preferred, 1 to 30 mol% is more preferred, 2 to 25 mol% is even more preferred, and 3 to 20 mol% is particularly preferred, based on the total (100 mol%) of all the constitutional units constituting the component (A1).

[0068] ≪Other Constitutional Units≫ In addition to the above-described constitutional unit (a0), the component (A1) may optionally have other constitutional units. Examples of other structural units include, for example, the structural unit (a1) described below; the structural unit (a10) represented by the general formula (a10-1) described below; the structural unit (a2) containing a lactone-containing cyclic group; the structural unit (a5) that generates an acid upon exposure; the structural unit (a6) having acid diffusion control properties; the structural unit (a8) derived from the compound represented by the general formula (a8-1) described below, and the like.

[0069] ≪Structural unit (a1)≫ The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases by the action of an acid.

[0070] Examples of the acid-dissociable group include those proposed as the acid-dissociable group of the base resin for chemically amplified resist compositions. Specific examples of those proposed as the acid-dissociable group of the base resin for chemically amplified resist compositions include the "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", "tertiary alkyloxycarbonyl acid-dissociable group", and "secondary alkyloxycarbonyl acid-dissociable group" described below.

[0071] Acetal-type acid-dissociable group: Examples of the acid-dissociable group that protects a carboxy group or a hydroxy group among the polar groups include, for example, the acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable group").

[0072]

Chemical formula

[0073] In formula (a1-r-1), Ra’ 1 and Ra’2 Among them, at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. Ra’ 1 or Ra’ 2 When it is an alkyl group, examples of the alkyl group include the same alkyl groups as those listed as substituents that may be bonded to the carbon atom at the α-position in the description of the above α-substituted acrylic acid ester, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, 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, etc. are mentioned, a methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0074] In formula (a1-r-1), Ra’ 3 Examples of the hydrocarbon group of include a linear or branched alkyl group or 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. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. are mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0075] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc. are mentioned, and an isopropyl group is preferred.

[0076] Ra’ 3 When it is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable. As the polycycloalkane, those having 7 to 12 carbon atoms are preferable, and specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane and the like can be mentioned.

[0077] Ra’ 3 When the cyclic hydrocarbon group of Ra’ becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group 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 of 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; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom, and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, and the like. Ra’ 3Specific examples of the aromatic hydrocarbon group in [description] include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (such as 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 of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0078] Ra’ 3 The cyclic hydrocarbon group in [description] may have a substituent. Examples of this substituent include -RP1, -RP2-O-RP1, -RP2-CO-RP1, -RP2-CO-ORP1, -RP2-O-CO-RP1, -RP2-OH, -RP2-CN or -RP2-COOH (hereinafter these substituents are also collectively referred to as "Rax5"). Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, some or all of the hydrogen atoms of the linear saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group and aromatic hydrocarbon group of R P1 and R P2 may be substituted with fluorine atoms. The above aliphatic cyclic hydrocarbon group may have one or more of the above substituents alone, or may have one or more of a plurality of the above 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, a decyl group, etc. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a cyclododecyl group, etc.; polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, an adamantyl group, etc. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, etc.

[0079] Ra’ 3 is Ra’ 1 , Ra’ 2 When bonding to any of them to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, etc.

[0080] Tertiary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a 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 composed of an alkyl group may be hereinafter referred to as "tertiary alkyl ester type acid dissociable groups" for convenience.

[0081] [Chemical formula] [In the formula, Ra’ 4 ~Ra’ 6Each is a hydrocarbon group, Ra’ 5 and Ra’ 6 may combine with each other to form a ring.]

[0082] Ra’ 4 Examples of the hydrocarbon group of Ra’ include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group. 4 Examples of the linear or branched alkyl group and cyclic hydrocarbon group (aliphatic hydrocarbon group which is a monocyclic group, aliphatic hydrocarbon group which is a polycyclic group, aromatic hydrocarbon group) in Ra’ 3 are the same as those of the above Ra’ Ra’ 4 The linear or cyclic alkenyl group in Ra’ Ra’ 5 and Ra’ 6 Examples of the hydrocarbon group of Ra’ 3 are the same as those of the above Ra’

[0083] Ra’ 5 When Ra’ 6 and Ra’ When Ra’ 4 to Ra’ 6 do not combine with each other and are independent hydrocarbon groups, the group represented by the following general formula (a1-r2-4) is preferably mentioned.

[0084]

Chemical formula

[0085] 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.

[0086] Ra’ 10 As the linear alkyl group in, it has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra’ 10 As the branched alkyl group in, those similar to the above Ra’ 3 can be mentioned.

[0087] Ra’ 10The alkyl group in [description] 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. Also, some of the carbon atoms (such as methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of the heteroatom mentioned here include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc.

[0088] In formula (a1-r2-1), Ra’ 11 (The aliphatic cyclic group formed together with the carbon atom to which Ra’ 10 is bonded) is preferably a group exemplified as the aliphatic hydrocarbon group (alicyclic hydrocarbon group) which is a monocyclic group or a polycyclic group of Ra’ 3 in formula (a1-r-1). Among them, a monocyclic alicyclic hydrocarbon group is preferred, and specifically, a cyclopentyl group and a cyclohexyl group are more preferred.

[0089] As the cyclic hydrocarbon group formed by Xa together with Ya in formula (a1-r2-2), a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) of Ra’ 3 in the above formula (a1-r-1) can be mentioned. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of this substituent include the same ones as the substituents that the cyclic hydrocarbon group of Ra’ 3 in the above may have. In formula (a1-r2-2), examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms for Ra 101 ~Ra 103 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 decyl group, etc. Ra 101 ~Ra 103Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.0 2,6 decanyl group, tricyclo[3.3.1.1 3,7 decanyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 dodecanyl group, polycyclic aliphatic saturated hydrocarbon groups such as adamantyl group, etc. are mentioned. Ra 101 ~Ra 103 Among them, from the viewpoint of ease of synthesis, a hydrogen atom and a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms are preferable, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0090] The above-mentioned Ra 101 ~Ra 103 Examples of the substituent of the chain-like saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by include the same groups as those of the above-mentioned Ra x5 for example.

[0091] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of them bonding to each other to form a cyclic structure include cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, cyclohexylideneethenyl group, etc. Among them, from the viewpoint of ease of synthesis, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferable.

[0092] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is preferably the group mentioned as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra’ 3 in formula (a1-r-1). In formula (a1-r2-3), Ra104 Examples of the aromatic hydrocarbon group in [description] include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 104 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

[0093] Ra in formula (a1-r2-3) 104 Examples of the substituent that Ra may have include, for example, a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), an alkyloxycarbonyl group, and the like.

[0094] In formula (a1-r2-4), Ra’ 12 and Ra’ 13 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. Ra’ 12 and Ra’ 13 Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in [description] include the same ones as the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in the above Ra 101 ~Ra 103 Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 Among them, an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group and an ethyl group are still more preferable, and a methyl group is particularly preferable. When the linear saturated hydrocarbon group represented by the above Ra’ 12 and Ra’ 13 is substituted, examples of the substituent include, for example, the same groups as the above Ra x5 ​

[0095] In formula (a1-r2-4), Ra’ 14 is a hydrocarbon group which may have a substituent. Ra’ 14 Examples of the hydrocarbon group in Ra’ include a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0096] Ra’ 14 The linear alkyl group in Ra’ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, 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.

[0097] Ra’ 14 The branched alkyl group in Ra’ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferred.

[0098] Ra’ 14 When Ra’ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may also be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, examples include cyclopentane, cyclohexane, etc. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred. The polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, examples include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, etc.

[0099] Ra’ 14 Examples of the aromatic hydrocarbon group in 14 include Ra 104 Similar groups to the aromatic hydrocarbon group in 104 can be mentioned. Among them, Ra’ 14 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably a group obtained by removing one or more hydrogen atoms from naphthalene. Ra’ 14 Examples of the substituent that Ra’ 104 may have include the same substituents as those that Ra 104 may have.

[0100] When Ra’ 14 in formula (a1-r2-4) is a naphthyl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1-position or the 2-position of the naphthyl group. When Ra’ 14 in formula (a1-r2-4) is an anthryl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any of the 1-position, 2-position or 9-position of the anthryl group.

[0101] Specific examples of the group represented by the formula (a1-r2-1) are given below.

[0102]

Chemical formula

[0103]

Chemical formula

[0104]

Chemical formula

[0105] Specific examples of the group represented by the formula (a1-r2-2) are given below.

[0106]

Chemical formula

[0107]

Chemical formula

[0108]

Chemical formula

[0109] Specific examples of the group represented by the formula (a1-r2-3) are given below.

[0110]

Chemical formula

[0111] Specific examples of the group represented by the formula (a1-r2-4) are given below.

[0112]

Chemical formula

[0113] Tertiary alkyloxycarbonyl acid-dissociable group: Among the above polar groups, examples of the acid-dissociable group for protecting the hydroxyl group include an acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as "tertiary alkyloxycarbonyl acid-dissociable group" for convenience).

[0114]

Chemical formula

[0115] In formula (a1-r-3), Ra’ 7 ~Ra’ 9 is each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. Further, the total number of carbon atoms of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0116] Secondary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a carboxy group include an acid dissociable group represented by the following general formula (a1-r-4).

[0117] [Chemical formula] [In the formula, Ra’ 10 is a hydrocarbon group. Ra’ 11a and Ra’ 11b are each independently a hydrogen atom, a halogen atom or an alkyl group. Ra’ 12 is a hydrogen atom or a hydrocarbon group. Ra’ 10 and Ra’ 11a or Ra’ 11b and Ra’ 11a or Ra’ 11b and Ra’ 12 may combine with each other to form a ring.]

[0118] In the formula, Ra’ 10 and Ra’ 12 Examples of the hydrocarbon group in include the same as those of the above Ra’ 3 In the formula, Ra’ 11a and Ra’ 11b Examples of the alkyl group in include the same as those of the alkyl group in the above Ra’ 1 In the formula, Ra’ 10 and Ra’ 12 the hydrocarbon group in, and Ra’​​11a and Ra’ 11b The alkyl group in 11b may have a substituent. Examples of this substituent include Ra x5 and the like.

[0119] Ra’ 10 and Ra’ 11a or Ra’ 11b may be bonded to each other to form a ring. The ring may be a polycyclic ring or a monocyclic ring, and may be an alicyclic ring or an aromatic ring. The alicyclic ring and the aromatic ring may contain heteroatoms.

[0120] Ra’ 10 and Ra’ 11a or Ra’ 11b Among the above, the rings formed by bonding Ra’ and Ra’ or Ra’ are preferably monocycloalkene, a ring in which some of the carbon atoms of monocycloalkene are substituted with heteroatoms (such as oxygen atoms, sulfur atoms), and monocycloalkadiene. Cycloalkenes having 3 to 6 carbon atoms are preferred, and cyclopentene or cyclohexene is preferred.

[0121] Ra’ 10 and Ra’ 11a or Ra’ 11b The ring formed by bonding Ra’ and Ra’ or Ra’ may be a fused ring. Specific examples of the fused ring include indane and the like.

[0122] Ra’ 10 and Ra’ 11a or Ra’ 11b The ring formed by bonding Ra’ and Ra’ or Ra’ may have a substituent. Examples of this substituent include Ra x5 and the like.

[0123] Ra’ 11a or Ra’ 11b and Ra’ 12 may be bonded to each other to form a ring. As the ring, 10 between Ra’ 11a and Ra’ 11bExamples thereof include those similar to the rings formed by bonding to each other.

[0124] Specific examples of the group represented by the formula (a1-r-4) are given below.

[0125] [Chemical formula]

[0126] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, a structural unit derived from acrylamide, a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group, and a structural unit in which at least a part of the hydrogen atoms in -C(=O)-OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected by a substituent containing the acid-decomposable group.

[0127] Among them, as the structural unit (a1), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent is preferable. Preferable specific examples of such a structural unit (a1) include structural units represented by the following general formulas (a1-1), (a1-2), or (a1-3).

[0128] [Chemical formula] [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. Va 1 is a divalent hydrocarbon group that may have an ether bond. n a1 is an integer from 0 to 2. Ra 1 is an acid dissociable group represented by the above general formula (a1-r-1), (a1-r-2), or (a1-r-4). Wa 1 is n a2is a monovalent hydrocarbon group. n a2 is an integer from 1 to 3. Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3). Ya 001 is a single bond or a divalent linking group. Ya 01 is a single bond or a divalent linking group. Rax 01 is an acid dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). Rz 01 is an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group. q is an integer from 0 to 3. n is an integer of 0 or more. However, n ≦ q × 2 + 4.]

[0129] In the above formulas (a1-1) to (a1-3), 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. Specifically, 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, etc. can be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0130] 1 The divalent hydrocarbon group in Va

[0131] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in the structure, and the like.

[0132] The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0133] Examples of the aliphatic hydrocarbon group containing a ring in the above structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those of the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, etc. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, etc.

[0134] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in Va 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 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. However, the carbon atom count does not include the carbon atom count in the substituent. Specific examples of the aromatic ring of 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 obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom 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 (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0135] In the formula (a1-1), Ra 1 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4). Among these, a group represented by the general formula (a1-r2-1) or an acid dissociable group represented by the general formula (a1-r-4) is more preferable.

[0136] In the formula (a1-2), Wa 1 The n a2 +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, which may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group combining a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure. The n a2 +1-valent is preferably divalent to tetravalent, and more preferably divalent or trivalent. In the formula (a1-2), Ra 2 is preferably an acid dissociable group represented by the above general formula (a1-r-1).

[0137] In the formula (a1-3), Ya 001The divalent linking group in [the relevant context] is not particularly limited, but examples of suitable ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. Ya 001 As [this], an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond is preferable. The number of carbon atoms of the alkylene group is preferably from 1 to 10, more preferably from 1 to 6, still more preferably from 1 to 4, and particularly preferably from 1 to 3. Among these, Ya 001 As [this], a combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group, or a single bond is more preferable, and a single bond is even more preferable.

[0138] In the formula (a1-3), Ya 01 The divalent linking group in [this] is not particularly limited, but examples of suitable ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. Ya 01 Among these, Ya is preferably an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. Among these, Ya 01 As [this], a combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group, or a single bond is more preferable, and a single bond is even more preferable.

[0139] In the formula (a1-3), Rax 01 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4). Among these, an acid dissociable group represented by the general formula (a1-r-2) is more preferable, and a group represented by the general formula (a1-r2-1) is even more preferable.

[0140] In the formula (a1-3), Rz 01 The alkyl group, halogenated alkyl group, and alkoxy group in 01 preferably have 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, still more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkyl group, halogenated alkyl group, and alkoxy group may be linear or branched chain. Rz 01 As the halogen atom in 01 , an iodine atom is preferable. Rz 01 As the halogen atom of the halogenated alkyl group in 01 , a fluorine atom, iodine atom, or bromine atom is preferable, and a fluorine atom is more preferable. Rz 01 Is preferably an alkoxy group or a hydroxy group, and more preferably a hydroxy group.

[0141] In the formula (a1-3), q is an integer of 0 to 3. When q is 0, it is a benzene structure, when q is 1, it is a naphthalene structure, when q is 2, it is an anthracene structure, and when q is 3, it is a tetracene structure. In the formula (a1-3), n is an integer of 0 or more, preferably 0 to 5, more preferably 0 to 3, and still more preferably 1 or 2. When n is an integer of 2 or more, two or more Rz 01 May be the same as or different from each other. In the formula (a1-3), n ≦ q × 2 + 4. For example, when q is 1 and it is a naphthalene structure, all 6 hydrogen atoms of the naphthalene may be substituted with hydroxy groups. Also, in the naphthalene, Ya 001 ,-Ya 01 -C(=O)-O-Ra 01 The substitution positions of the group and the hydroxy group are not particularly limited.

[0142] Specific examples of the structural unit (a1) are shown below. In the following formulas, R α Represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0143]

Chemical formula

[0144]

Chem.

[0145]

Chem.

[0146]

Chem.

[0147]

Chem.

[0148]

Chem.

[0149]

Chem.

[0150]

Chem.

[0151]

Chem.

[0152] In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group. Rz represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group.

[0153]

Chem.

[0154] [Chem.]

[0155] [Chem.]

[0156] [Chem.]

[0157] [Chem.]

[0158] The structural unit (a1) contained in the component (A1) may be one type or two or more types. As the structural unit (a1), the structural unit represented by the above formula (a1-1) or the structural unit represented by the above formula (a1-3) is more preferable because the characteristics (sensitivity, shape, etc.) in lithography using an electron beam or EUV can be more easily enhanced. Among them, since it is suitable for enhancing the reactivity in the case of EB or EUV, the acid dissociable groups (Ra 1 , Rax 01 ) are preferably acid dissociable groups represented by the above general formulas (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4), respectively, and among them, it is particularly preferable to select those that are cyclic groups.

[0159] Alternatively, as the structural unit (a1), those containing the structural unit represented by the following general formula (a1-1-1) may be used.

[0160] [Chem.] [In the formula, Ra 1" is an acid dissociable group represented by general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4). * indicates a bond.]

[0161] In the formula (a1-1-1), R, Va 1 and n a1 are the same as R, Va 1 and n a1 in the formula (a1-1).

[0162] The description of the acid dissociable group represented by general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4) is as described above. Among them, since it is suitable for enhancing reactivity in EB or EUV, it is preferable to select an acid dissociable group that is a cyclic group.

[0163] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 70 mol% with respect to the total of all the structural units (100 mol%) constituting the component (A1). By setting the proportion of the structural unit (a1) to be equal to or higher than the lower limit value of the above preferred range, lithography characteristics such as sensitivity, resolution, and CDU improvement are improved. On the other hand, when it is equal to or lower than the upper limit value of the above preferred range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0164] Structural unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0165] [Chemical formula] [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. Ya x1 is a single bond or a divalent linking group. Wa x1is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more. ]

[0166] In the formula (a10-1), R is the same as R in the general formula (a1-1). As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is particularly preferable.

[0167] 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 is the same as Y in the general formula (a0-m0). 0 is the same.

[0168] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in includes a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic ring which may have a substituent. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons. The number of carbon atoms of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom, and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Further, the aromatic hydrocarbon group in Wa x1 also includes a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic compound (for example, biphenyl, fluorene, etc.) containing an aromatic ring which may have two or more substituents. Among these, Wa x1 is preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene, naphthalene, anthracene or biphenyl, more preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene or naphthalene, and even more preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene.

[0169] The aromatic hydrocarbon group in Wa x1 may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, etc. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent are the same as those exemplified as the substituent of the cyclic aliphatic hydrocarbon group in Ya x1 . 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, even more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. The aromatic hydrocarbon group in Wa x1 preferably has no substituent.

[0170] 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, even more preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0171] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0172]

Chemical formula

[0173] [Chemistry]

[0174] [Chemistry]

[0175] (A1) component may have one or more than two kinds of structural units (a10). (A1) component may or may not have the structural unit (a10), but it is preferable to have the structural unit (a10). When the (A1) component has the structural unit (a10), the proportion of the structural unit (a10) in the (A1) component is preferably 20 to 80 mol%, more preferably 25 to 70 mol%, still more preferably 30 to 60 mol%, and particularly preferably 30 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the (A1) component. By setting the proportion of the structural unit (a10) to be not less than the lower limit value, the sensitivity is more easily increased. On the other hand, by setting it to be not more than the upper limit value, it is easier to balance with other structural units.

[0176] Structural unit (a2): (A1) component may or may not have a structural unit (a2) containing a lactone-containing cyclic group (excluding those corresponding to the structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the (A1) component is used for forming the resist film. Also, by having the structural unit (a2), for example, effects such as appropriately adjusting the acid diffusion length, enhancing the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development make the lithography characteristics and the like good.

[0177] The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) having -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, when there is only the lactone ring, it is a monocyclic group, and when it further has other ring structures, regardless of the structure, it is called a polycyclic group. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group in the constituent unit (a2), any group can be used without particular limitation. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

[0178] [Chemical formula] [In the formula, Ra’ 21 each independently represents 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” represents a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A” represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom, n’ is an integer of 0 to 2, and m’ is 0 or 1. * represents a bond (the same applies hereinafter).]

[0179] In the general formulas (a2-r-1) to (a2-r-7), Ra’ 21 the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, 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, a hexyl group, etc. can be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. Ra’ 21 the alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the above Ra’ 21Examples of the group in which the alkyl group mentioned as the alkyl group in [0000000] is linked to an oxygen atom (-O-) can be given. Ra’ 21 As the halogen atom in [0000000], a fluorine atom is preferred. Ra’ 21 As the alkyl halide group in [0000000], the Ra’ 21 Examples of the group in which some or all of the hydrogen atoms of the alkyl group in [0000000] are substituted with the halogen atom can be given. As the alkyl halide group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0180] Ra’ 21 In -COOR” and -OC(=O)R” in [0000000], each of R” is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. As the alkyl group in R”, any of linear, branched, or cyclic groups may be used, and the number of carbon atoms is preferably 1 to 15. When R” is a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably a methyl group or an ethyl group. When R” is a cyclic alkyl group, the number of carbon atoms is preferably 3 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane can be exemplified. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, and tetracyclododecane can be given. Examples of the lactone-containing cyclic group in R” include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7) respectively. Ra’ 21 As the hydroxyalkyl group in 21 , those having 1 to 6 carbon atoms are preferable. Specifically, at least one hydrogen atom of the alkyl group in the above Ra’ 21 is a group in which the hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0181] Ra’ 21 Among them, Ra’ is preferably independently a hydrogen atom or a cyano group.

[0182] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), as the alkylene group having 1 to 5 carbon atoms in A”, a linear or branched alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropyl group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is interposed at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. As A”, an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

[0183] Specific examples of the groups represented by the general formulas (a2-r-1) to (a2-r-7) are given below.

[0184]

Chemical formula

[0185]

Chemical formula

[0186] As the constitutional unit (a2), among others, a constitutional unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable. Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0187] [Chemical formula] [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. Ya 21 is a single bond or a divalent linking group. La 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La 21 is -O-, Ya 21 is not -CO-. Ra 21 is a lactone-containing cyclic group.]

[0188] In the formula (a2-1), R is the same as described above. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is particularly preferable.

[0189] In the formula (a2-1), the divalent linking group in Ya 21 is not particularly limited, but examples thereof preferably include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. The divalent linking group in Ya 21 is the same as the divalent linking group in Ya x1 in the above general formula (a10-1).

[0190] 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.

[0191] In the formula (a2-1), Ya 21 is preferably a single bond, and La 21 is preferably -COO- or -OCO-.

[0192] In the formula (a2-1), Ra 21 is a lactone-containing cyclic group. As the lactone-containing cyclic group in Ra 21 the groups respectively represented by the general formulas (a2-r-1) to (a2-r-7) described above are preferably exemplified.

[0193] (A1) component may have one or more kinds of structural units (a2), or may not have any. (A1) component may have the structural unit (a2), or may not have it. When the (A1) component has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and still more preferably 1 to 10 mol% with respect to the total (100 mol%) of all the structural units constituting the (A1) component. When the proportion of the structural unit (a2) is set to be not less than the preferable lower limit value, the effect of containing the structural unit (a2) can be sufficiently obtained by the above-described effect. When it is not more than the upper limit value, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0194] Structural unit (a5): (A1) component may have the structural unit (a5) that generates an acid upon exposure, or may not have it. As the structural unit (a5), known ones can be used. By having the structural unit (a5), the acid generated upon exposure is likely to be uniformly distributed in the resist film. As the structural unit (a5), the structural units including the structures described in the following (B) component are exemplified. For example, the structural units including the structures represented by any of the following general formulas (b-1) to (b-3) are exemplified. As the structural unit (a5), for example, the structural unit represented by the following general formula (a5-1) is preferably exemplified.

[0195] [Chemical formula] [In the formula, R m is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. La 50 is a divalent linking group or a single bond. Ra 50 is a divalent hydrocarbon group which may have a substituent. n a5 is an integer of 0 to 2. La 51 is a divalent linking group. Ya 5 is a divalent linking group which may have a hetero atom, or a single bond. Ra 51 and Ra 52 are each independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. n5 is an integer of 1 to 4. m is an integer of 1 or more, and M’ m+ is an m-valent onium cation.]

[0196] {Anion part} In the formula (a5-1), R m is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. R m The alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, 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, etc. may be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Among the halogen atoms in the halogenated alkyl group, a fluorine atom is particularly preferable. R m 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 easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0197] In the formula (a5-1), La 50 is a divalent linking group or a single bond. La 50 The divalent linking group in La is not particularly limited, but a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom are preferably mentioned. Each of them is the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom exemplified as the divalent linking group in the above Ya x1 above. Among the above, as La 50 it is preferably an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond. Among these, as La 5 it is more preferably an ester bond [-C(=O)-O-, -O-C(=O)-] or a single bond, and even more preferably an ester bond [-C(=O)-O-, -O-C(=O)-].

[0198] In the formula (a5-1), Ra 50 is a divalent hydrocarbon group which may have a substituent. Ra 50 The divalent hydrocarbon group in Ra may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0199] ··Ra 50 The aliphatic hydrocarbon group in The aliphatic hydrocarbon group means a hydrocarbon group having no 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, or an aliphatic hydrocarbon group containing a ring in the structure.

[0200] ···A linear or branched aliphatic hydrocarbon group The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. can be mentioned. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0201] The above-mentioned linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, etc.

[0202] ···an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms 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 terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane and the like.

[0203] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and the like. The alkyl group as the substituent preferably has 1 to 5 carbon atoms, and most preferably is a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. The alkoxy group as the substituent preferably has 1 to 5 carbon atoms, more preferably is 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 is a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group are 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. Preferred examples of the substituent containing a heteroatom include -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0204] ··Ra 50 the aromatic hydrocarbon group in The aromatic hydrocarbon group 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, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the 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; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, etc. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0205] In the aromatic hydrocarbon group, the hydrogen atoms of the aromatic hydrocarbon group may be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of the substituents include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0206] In the formula (a5-1), n a5 is an integer of 0 to 2. Among the above, Ra 50 preferably has an aliphatic hydrocarbon group containing a ring in the structure, more preferably a cyclic aliphatic hydrocarbon group which may contain a substituent containing a heteroatom in the ring structure, and still more preferably an alicyclic hydrocarbon group which may have a substituent and is a polycyclic group or a monocyclic group. Alternatively, among the above, Ra 50 is preferably an aromatic hydrocarbon group.

[0207] n a5 When n is 2, the two Ra 50 may each be an alicyclic hydrocarbon group which may have a substituent, may each be an aromatic hydrocarbon group, or may be a combination of an alicyclic hydrocarbon group and an aromatic hydrocarbon group which may have a substituent.

[0208] In the formula (a5-1), La 51 is a divalent linking group. La 51 Examples of the divalent linking group in La include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-O-C(=O)-O-); combinations of such non-hydrocarbon oxygen atom-containing linking groups and an alkylene group, etc. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such a divalent linking group include linking groups respectively represented by the following general formulas (L-al-1) to (L-al-8). In the following general formulas (L-al-1) to (L-al-8), that which binds to Ra 50 in the above formula (a5-1) is V’ 101 in the following general formulas (L-al-1) to (L-al-8).

[0209]

Chemical formula

[0210] 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.

[0211] V’ 101 and V’ 102 The alkylene group in and V’ may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred. V’ 101 and V’ 102 Specific examples of the alkylene group in and V’ include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-; a pentamethylene group [-CH2CH2CH2CH2CH2-], and the like. Also, V’ 101 or V’ 102 Some of the methylene groups in the alkylene group in or V’ may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) of Ra’ in the formula (a1-r-1). 3 is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) of Ra’ in the formula (a1-r-1), more preferably a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group.

[0212] La 51As 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 formulas (L-al-1) to (L-al-5) and (L-al-8) are more preferable, and the linking group represented by (L-al-3) or (L-al-8) is even more preferable.

[0213] In the formula (a5-1), Ya 5 is a divalent linking group which may have a heteroatom or a single bond. Ya 5 The divalent linking group in Ya is not particularly limited, but preferably includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. Ya 5 Regarding the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom in Ya, they are the same as the divalent linking group in Ya x1 exemplified above, that is, a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom. Among the above, as Ya 5 a linear or branched alkylene group or a single bond is preferable, and a single bond is more preferable.

[0214] In the formula (a5-1), Ra 51 and Ra 52 are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group. Ra 51 and Ra 52 The fluorinated alkyl group in Ra is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, and more preferably a trifluoromethyl group. In the formula (a5-1), for Ra - and Ra 51 bonded to the carbon atom adjacent to SO3 52 at least one of them is preferably a fluorine atom from the viewpoint of acid strength.

[0215] In the formula (a5-1), n5 is an integer of 1 to 4, and 1, 2 or 3 is preferable.

[0216] {Cation part} In the above formula (a5-1), M’ m+ represents an m-valent onium cation. Among these, M’ m+ is preferably a sulfonium cation or an iodonium cation. m is an integer of 1 or more.

[0217] Preferred cation parts ((M’ m+ )) 1 / m include organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0218] [Chemical formula] [In the formula, R 201 ~R 207 each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R 201 ~R 203 , R 206 ~R 207 may be bonded to each other to form a ring together with the sulfur atom in the formula. R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO2-containing cyclic group which may have a substituent. L 201 represents -C(=O)- or -C(=O)-O-.]

[0219] In the above general formulas (ca-1) to (ca-3), the aryl group in R 201 ~R 207 includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. R 201 ~R 207 The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R201 ~R 207 As the alkenyl group in ~R, it is preferable that the number of carbon atoms is 2 to 10. R 201 ~R 207 and R 210 Examples of the substituent that ~R and R may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, a group represented by the following general formulas (ca-r-1) to (ca-r-7), and the like.

[0220]

Chemical formula

[0221] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0222] R’ 201 The aromatic hydrocarbon group in R’ is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R’ 201Specific examples of the aromatic ring of the aromatic hydrocarbon group in [reference] include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. R’ 201 Specific examples of the aromatic hydrocarbon group in [reference] include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0223] R’ 201 The cyclic aliphatic hydrocarbon group in [reference] includes an aliphatic hydrocarbon group containing a ring in its structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 20, and more preferably 3 to 12. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferable, and as the polycycloalkane, those having 7 to 30 carbon atoms are preferable. Among them, as the polycycloalkane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0224] Among them, 201 as the cyclic aliphatic hydrocarbon group in R’, a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane is preferable, a group obtained by removing one hydrogen atom from polycycloalkane is more preferable, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

[0225] 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 linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-] and the like can be mentioned. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferable. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0226] Also, R’ 201 The cyclic hydrocarbon group in may contain a hetero atom such as a heterocyclic ring. Specifically, lactone-containing cyclic groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the following general formulas (b5-r-1) to (b5-r-4), and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16) can be mentioned.

[0227]

Chemical formula

[0228] R’ 201 Examples of the substituent in the cyclic group of include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group and the like. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. As the halogen atom as a substituent, a fluorine atom is preferable. As the halogenated alkyl group as a substituent, a group in which a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., are substituted with the halogen atom can be mentioned. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) constituting a cyclic hydrocarbon group.

[0229] A chain alkyl group which may have a substituent: R’ 201 As the chain alkyl group of, it may be either linear or branched. As the linear alkyl group, it is preferably having 1 to 20 carbon atoms, more preferably having 1 to 15 carbon atoms, and most preferably having 1 to 10 carbon atoms. As the branched alkyl group, it is preferably having 3 to 20 carbon atoms, more preferably having 3 to 15 carbon atoms, and most preferably having 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, etc. can be mentioned.

[0230] A chain alkenyl group which may have a substituent: R’ 201The chain-like alkenyl group may be either linear or branched, preferably having 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 vinyl group, propenyl group (allyl group), butenyl group, and the like. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group, and the like. Among the above, the chain-like alkenyl group is preferably a linear alkenyl group, more preferably vinyl group or propenyl group, and particularly preferably vinyl group.

[0231] R’ 201 Examples of the substituent in the chain-like alkyl group or alkenyl group of include alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, carbonyl group, nitro group, amino group, and the cyclic group in the above R’ 201 and the like.

[0232] R’ 201 The cyclic group which may have a substituent, the chain-like alkyl group which may have a substituent, or the chain-like alkenyl group which may have a substituent may, in addition to those described above, include the same ones as the acid dissociable group represented by the above formula (a1-r-2) as the cyclic group which may have a substituent or the chain-like alkyl group which may have a substituent.

[0233] 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 obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) respectively; a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4) described later, and the like are preferable.

[0234] In the above general formulas (ca-1) to (ca-3), R 201 ~R203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may be bonded via a heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom, or a functional group such as a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )(wherein the R N is an alkyl group having 1 to 5 carbon atoms). The ring formed is preferably a 3- to 10-membered ring including the sulfur atom in the formula, and particularly preferably a 5- to 7-membered ring including the sulfur atom. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

[0235] 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 it is an alkyl group, they may be bonded to each other to form a ring.

[0236] R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO2-containing cyclic group which may have a substituent. R 210 Examples of the aryl group in R include an unsubstituted aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group. 210 Examples of the alkyl group in R include a chain or cyclic alkyl group having preferably 1 to 30 carbon atoms. 210 Examples of the alkenyl group in R preferably have 2 to 10 carbon atoms. 210In the formula, as the -SO2-containing cyclic group, any group can be used without particular limitation. Specifically, groups represented by the following general formulas (b5-r-1) to (b5-r-4) can be mentioned. A "-SO2-containing polycyclic group" is preferred, and a group represented by the general formula (b5-r-1) is more preferred.

[0237] [Chemical formula] [In the formula, Rb’ 51 each independently represents 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” represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO2-containing cyclic group; B” represents 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. * represents a bond.]

[0238] In the general formulas (b5-r-1) to (b5-r-2), B” represents 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. As B”, an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is even more preferred.

[0239] In the general formulas (b5-r-1) to (b5-r-4), Rb’ 51 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group, and among them, each independently being a hydrogen atom or a cyano group is preferred.

[0240] Specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4) are shown below. “Ac” in the formula represents an acetyl group.

[0241] [Chemical formula]

[0242] [Chemical formula]

[0243] [Chemical formula]

[0244] Specific examples of the preferred cation represented by the formula (ca-1) include cations represented by the following chemical formulas, respectively.

[0245] [Chemical formula]

[0246] [Chemical formula]

[0247] [Chemical formula] [In the formula, g1, g2, and g3 represent the number of repetitions. g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[0248] [Chemical formula]

[0249] [Chemical formula]

[0250] [Chemical formula] [In the formula, R” 201is a hydrogen atom or a substituent, and examples of the substituent include the aforementioned R 201 ~R 207 , and R 210 ~R 212 are the same as those listed as the substituents that may be possessed.]

[0251]

Chemical formula

[0252] Specific examples of the preferred cation represented by the formula (ca-2) include a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, and the like.

[0253] Specific examples of the preferred cation represented by the formula (ca-3) include cations respectively represented by the following formulas (ca-3-1) to (ca-3-6).

[0254]

Chemical formula

[0255] As the cation moiety ((M’ m+ )) 1 / m ) in the formula (a5-1), a sulfonium cation is preferable, cations respectively represented by the formulas (ca-1) to (ca-3) are more preferable, the cation represented by the formula (ca-1) is still more preferable, and cations respectively represented by the formulas (ca-1-1) to (ca-1-84) are particularly preferable. From the viewpoint of particularly enhancing the sensitivity, as the preferred cation represented by the formula (ca-1), those having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent are preferable. For example, cations selected from the group consisting of the cations respectively represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84) are particularly preferable.

[0256] Specific preferred examples of the structural unit (a5) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. m and M' m+ are the same as m and M' m+ in the general formula (a5-1) above.

[0257]

Chemical formula

[0258]

Chemical formula

[0259]

Chemical formula

[0260] The structural unit (a5) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) contains the structural unit (a5), the proportion of the structural unit (a5) in the component (A1) is preferably 5 to 25 mol%, more preferably 10 to 20 mol%, and even more preferably 15 to 20 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). When the proportion of the structural unit (a5) is equal to or higher than the lower limit value of the above-mentioned preferred range, it becomes easier to achieve further higher sensitivity and improved resolution. On the other hand, when it is equal to or lower than the upper limit value of the above-mentioned preferred range, it becomes easier to balance with other structural units.

[0261] Structural unit (a6): The structural unit (a6) is a structural unit having acid diffusion controllability. The component (A1) may or may not contain the structural unit (a6). Known structural units can be used as the structural unit (a6). Examples of the structural unit (a6) include structural units containing the structures described in the components (D1) and (D2) described below. For example, structural units containing the structures represented by any of the general formulas (d1-1) to (d1-3) described below can be mentioned.

[0262] (A1) component may have one or more than two kinds of structural units (a6). When (A1) component has structural unit (a6), the proportion of structural unit (a6) in (A1) component is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, still more preferably 3 to 10 mol% with respect to the total (100 mol%) of all structural units constituting (A1) component. When the proportion of structural unit (a6) is equal to or higher than the lower limit value of the above - mentioned preferred range, it becomes easier to realize further high - sensitivity. On the other hand, when it is equal to or lower than the upper limit value of the above - mentioned preferred range, it becomes easier to balance with other structural units.

[0263] Structural unit (a8): Structural unit (a8) is a structural unit derived from a compound represented by the following general formula (a8 - 1). (A1) component may or may not have structural unit (a8).

[0264] [Chemical formula] [In the formula, W 2 is a polymerizable - group - containing group. Ya x2 is a single bond or an (n ax2 +1) - valent linking group. Ya x2 and W 2 may form a condensed ring. R 1 is a fluorinated alkyl group having 1 to 12 carbon atoms. R 2 is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. R 2 and Ya x2 may be bonded to each other to form a ring structure. n ax2 is an integer of 1 to 3. ]

[0265] W 2 In the polymerizable - group - containing group of W, the "polymerizable group" means a group that enables a compound having a polymerizable group to polymerize by radical polymerization or the like, and for example, a group containing a multiple bond between carbon atoms such as an ethylenic double bond.

[0266] The group containing a polymerizable group may be a group composed only of polymerizable groups or a group composed of a polymerizable group and other groups other than the polymerizable group. Examples of the other groups other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. Examples of the group containing a polymerizable group include, for example, a group represented by the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 -. In this chemical formula, R X11 , R X12 and R X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 is a single bond or a divalent linking group.

[0267] Examples of the condensed ring formed by Ya x2 and W 2 include a condensed ring formed by the polymerizable group at the W 2 site and Ya x2 , and a condensed ring formed by a group other than the polymerizable group at the W 2 site and Ya x2 . The condensed ring formed by Ya x2 and W 2 may have a substituent.

[0268] Specific examples of the constitutional unit (a8) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0269]

Chemical formula

[0270] Among the above examples, the structural unit (a8) is preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-09).

[0271] (A1) component may have one or more than two structural units (a8). (A1) component may or may not have the structural unit (a8). The proportion of the structural unit (a8) in the (A1) component is preferably 0 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the (A1) component, and more preferably 0 to 30 mol%.

[0272] As the (A1) component contained in the resist composition, one kind may be used alone, or two or more kinds may be used in combination.

[0273] Examples of the (A1) component include a polymer compound having the structural unit (a0) and the structural unit (a1); a polymer compound having the structural unit (a0) and the structural unit (a10); a polymer compound having the structural unit (a0), the structural unit (a1), and the structural unit (a10); a polymer compound having the structural unit (a0), the structural unit (a1), the structural unit (a10), and the structural unit (a2), etc. The (A1) component is preferably, for example, a polymer compound composed of the structural unit (a0), the structural unit (a1), and the structural unit (a10), a polymer compound composed of the structural unit (a0), the structural unit (a1), the structural unit (a10), and the structural unit (a2), etc.

[0274] In the polymer compound composed of the structural unit (a0), the structural unit (a1), and the structural unit (a10), the proportion of the structural unit (a0) is preferably 0.5 to 35 mol%, more preferably 1 to 30 mol%, still more preferably 2 to 25 mol%, and particularly preferably 3 to 20 mol% with respect to the total (100 mol%) of all the structural units constituting the polymer compound. The proportion of the constitutional unit (a1) in the polymer compound is preferably 30 to 80 mol%, more preferably 35 to 75 mol%, still more preferably 40 to 70 mol%, and particularly preferably 45 to 65 mol% with respect to the total of all constitutional units (100 mol%) constituting the polymer compound. The proportion of the constitutional unit (a10) in the polymer compound is preferably 1 to 65 mol%, more preferably 5 to 60 mol%, still more preferably 10 to 55 mol%, and particularly preferably 15 to 50 mol% with respect to the total of all constitutional units (100 mol%) constituting the polymer compound.

[0275] In the polymer compound composed of the constitutional unit (a0), the constitutional unit (a1), the constitutional unit (a10), and the constitutional unit (a2), the proportion of the constitutional unit (a0) is more preferably 0.5 to 35 mol%, still more preferably 1 to 30 mol%, and still more preferably 2 to 25 mol% with respect to the total of all constitutional units (100 mol%) constituting the polymer compound. The proportion of the constitutional unit (a1) in the polymer compound is preferably 30 to 80 mol%, more preferably 35 to 75 mol%, still more preferably 40 to 70 mol%, and particularly preferably 45 to 65 mol% with respect to the total of all constitutional units (100 mol%) constituting the polymer compound. The proportion of the constitutional unit (a10) in the polymer compound is preferably 1 to 65 mol%, more preferably 5 to 60 mol%, still more preferably 10 to 55 mol%, and particularly preferably 15 to 50 mol% with respect to the total of all constitutional units (100 mol%) constituting the polymer compound. The proportion of the constitutional unit (a2) in the polymer compound is preferably 0.5 to 35 mol%, more preferably 1 to 30 mol%, still more preferably 3 to 25 mol%, and particularly preferably 5 to 20 mol% with respect to the total of all constitutional units (100 mol%) constituting the polymer compound.

[0276] Such component (A1) can be produced by dissolving the monomers that induce each constitutional unit in a polymerization solvent, and adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (e.g., V-601, etc.) thereto, and then performing polymerization. Alternatively, such component (A1) can be produced by dissolving a monomer that induces a structural unit (a1) and a monomer that induces an arbitrary structural unit (for example, structural unit (a10), structural unit (a5), etc.) in a polymerization solvent, adding a radical polymerization initiator as described above thereto, polymerizing, and then performing a deprotection reaction. In addition, during polymerization, for example, by using a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH in combination, a -C(CF3)2-OH group may be introduced at the terminal. Thus, a copolymer into which a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is introduced is effective for reducing development defects and LER (Line Edge Roughness: non-uniform irregularities on the sidewalls of the line).

[0277] The weight average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1000 to 50000, more preferably 3000 to 40000, and even more preferably 5000 to 30000. When the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is above the preferred lower limit of this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good. The dispersity (Mw / Mn) of component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Note that Mn represents the number average molecular weight.

[0278] ·Regarding component (A2) The resist composition of the present embodiment may also use, as component (A), a base material component (hereinafter referred to as "component (A2)") that does not correspond to the above-mentioned component (A1) and whose solubility in a developer changes by the action of an acid. Component (A2) is not particularly limited, and may be arbitrarily selected and used from a number of those conventionally known as base material components for chemically amplified resist compositions. (Component (A2)) may be used alone or in combination of two or more of a high molecular compound or a low molecular compound.

[0279] The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, a resist pattern excellent in various lithography characteristics such as high sensitivity, resolution, and CDU improvement is likely to be formed.

[0280] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed and the like.

[0281] <Acid generator component (B)> The resist composition of this embodiment may contain an acid generator component (B) that generates an acid upon exposure. Component (B) is not particularly limited, and those 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 sulfonyldiazomethanes and poly(bissulfonyl)diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. The form of containing component (B) may be in the form of a compound, may be incorporated into component (A1) as the above structural unit (a5), or may be in both of these forms.

[0282] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "(b-1) component"), a compound represented by general formula (b-2) (hereinafter also referred to as "(b-2) component"), or a compound represented by general formula (b-3) (hereinafter also referred to as "(b-3) component").

[0283] Examples of the onium salt-based acid generators include a compound represented by the following general formula (b-1) (hereinafter also referred to as "(b-1) component"), a compound represented by the general formula (b-2) (hereinafter also referred to as "(b-2) component"), or a compound represented by the general formula (b-3) (hereinafter also referred to as "(b-3) component").

[0284] [Chemical formula] [In the formula, R 101 and R 104 ~R 108 are each independently a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. R 104 and R 105 may be bonded to each other to form a ring structure. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103 are each independently a single bond, an alkylene group or a fluorinated alkylene group. However, Y 101 and V 101 do not simultaneously become a single bond. L 101 ~L 102 are each independently a single bond or an oxygen atom. L 103 ~L 105 are each independently a single bond, -CO- or -SO2-. m is an integer of 1 or more, and M’ m+ is an m-valent onium cation.]

[0285] {Anion part} ·Anion in the (b-1) component In formula (b-1), R 101 is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.

[0286] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group is preferably saturated.

[0287] R 101 The aromatic hydrocarbon group in R is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring of the aromatic hydrocarbon group in R include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which a part of the carbon atoms constituting these aromatic rings is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101 Specific examples of the aromatic hydrocarbon group in R include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, etc.). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0288] R 101 The cyclic aliphatic hydrocarbon group in R includes an aliphatic hydrocarbon group containing a ring in the structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane; and polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0289] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane, more preferably a group obtained by removing one hydrogen atom from polycycloalkane, still more preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0290] 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 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-] and the like can be mentioned. The branched aliphatic hydrocarbon group, which may be bonded to an alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0291] Also, R 101 The cyclic hydrocarbon group in may contain a hetero atom such as a heterocyclic ring. Specifically, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16) can be mentioned.

[0292] R 101 Examples of the substituent in the cyclic group of include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group and the like. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferred. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. As the halogen atom as a substituent, a fluorine atom, a bromine atom, and an iodine atom are preferable. As the halogenated alkyl group as a substituent, a group in which a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., are substituted with the above halogen atoms can be mentioned. The carbonyl group as a substituent is a group that substitutes the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0293] R 101 The cyclic hydrocarbon group in may be a condensed cyclic group including a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the condensed ring include those in which one or more aromatic rings are condensed to a polycycloalkane having a bridged ring system polycyclic skeleton. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the condensed cyclic group, a group including a condensed ring in which 2 or 3 aromatic rings are condensed to a bicycloalkane is preferable, and a group including a condensed ring in which 2 or 3 aromatic rings are condensed to bicyclo[2.2.2]octane is more preferable. R 101 Specific examples of the condensed cyclic group in include those represented by the following formulas (r-br-1) to (r-br-2). In the formula, * represents a bond that binds to Y in the formula (b-1). 101 represents a bond that binds to Y in the formula (b-1).

[0294]

Chemical formula

[0295] R 101Examples of the substituent that the condensed cyclic group may have include, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and the like. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the condensed cyclic group are the same as those exemplified as the substituent of the cyclic group in R above. 101 The same ones as those exemplified as the substituent of the cyclic group in R above can be mentioned. Examples of the aromatic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from an aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., arylalkyl groups), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6), respectively. Examples of the alicyclic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane and cyclohexane; a group obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO2-containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), respectively; and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16), respectively.

[0296] The chain-like alkyl group that may have a substituent: R 101 The chain-like alkyl group of R may be either linear or branched. 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-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, etc. can be mentioned.

[0297] Optionally substituted chain alkenyl group: R 101 The chain alkenyl group of R may be either linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include vinyl group, propenyl group (allyl group), butenyl group, etc. Examples of the branched-chain alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group, etc. Among the above, the linear alkenyl group is preferred as the chain alkenyl group, and the vinyl group and propenyl group are more preferred, and the vinyl group is particularly preferred.

[0298] R 101 Examples of the substituent in the chain alkyl group or alkenyl group of R include alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, carbonyl group, nitro group, amino group, cyclic group in the above R 101 etc.

[0299] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, the Y 101 may contain atoms other than the oxygen atom. Examples of the atoms other than the oxygen atom include carbon atom, hydrogen atom, sulfur atom, nitrogen atom, etc. Examples of the divalent linking group containing an oxygen atom include the linking groups represented by the above general formulas (L-al-1) to (L-al-8), respectively. In the following general formulas (L-al-1) to (L-al-8), R in the above formula (b-1) 101 is bonded to V' in the following general formulas (L-al-1) to (L-al-8). 101 That is.

[0300] In the formula (b-1), V 101 is a single bond, an alkylene group or a fluorinated alkylene group. Among them, V 101 is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0301] In the formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0302] Specific examples of the anion part represented by the formula (b-1) include, for example, when Y 101 is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; when Y 101 is a divalent linking group containing an oxygen atom, anions represented by any of the following formulas (an-1) to (an-3) can be mentioned.

[0303] [Chemical formula] [In the formula, R'' 101 is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), a condensed cyclic group represented by the formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent or an aromatic cyclic group which may have a substituent. R'' 102R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or an -SO2- containing cyclic group represented by each of the above general formulas (b5-r-1) to (b5-r-4). 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 R 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.

[0304] R” 101 , R.” 102 and R.” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 As the substituent, R in the formula (b-1) is preferably a group exemplified as the cyclic aliphatic hydrocarbon group. 101 Examples of the substituents which may substitute the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0305] R” 101 and 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 The substituents which may substitute the aromatic hydrocarbon group in the above formula (I) are the same as those in the above formula (I).

[0306] 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 (I). R” 103 The chain alkenyl group which may have a substituent in 103 is preferably the group exemplified as the chain alkenyl group in R in the formula (b-1). 101

[0307] · Anion in the component (b-2) In the 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 examples thereof include the same as R in the formula (b-1). However, R 101 , R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 are 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 number of carbon atoms of the chain alkyl group is preferably 1 to 10, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The number of carbon atoms of the chain alkyl group of R 104 , R 105 is preferably smaller within the above range of the number of carbon atoms for reasons such as good solubility in the resist solvent. Also, in the chain alkyl group of R 104 , R 105 , the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the more preferable because the transparency to high-energy light or electron beam of 250 nm or less is improved. The ratio of fluorine atoms, that is, the fluorination rate, in the chain alkyl group 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 the formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof include the same as V in the formula (b-1).​101 The same ones can be mentioned. In formula (b-2), L 101 , L 102 is each independently a single bond or an oxygen atom.

[0308] · Anion in the (b-3) component In formula (b-3), R 106 ~R 108 is each independently a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and each is the same as R in formula (b-1) 101 The same ones can be mentioned. In formula (b-3), L 103 ~L 105 is each independently a single bond, -CO- or -SO2-.

[0309] Among the above, as the anion part of the component (B), the anion in the (b-1) component is preferable, and the anion represented by the formula (an-1) is more preferable.

[0310] {Cation part} In the above formulas (b-1), (b-2), and (b-3), M' m+ represents an m-valent onium cation. Among these, a sulfonium cation and an iodonium cation are preferable. m is an integer of 1 or more.

[0311] As the cation part of the component (B), a sulfonium cation is preferable, the cations respectively represented by the formulas (ca-1) to (ca-3) are more preferable, the cation represented by the formula (ca-1) is still more preferable, and the cations respectively represented by the formulas (ca-1-1) to (ca-1-84) are particularly preferable.

[0312] In the resist composition of this embodiment, the component (B) may be used alone or in combination of two or more. When the resist composition contains the component (B), in the resist composition, the content of the component (B) is preferably less than 50 parts by mass, more preferably 5 to 45 parts by mass, and even more preferably 10 to 43 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the component (B) within the above-preferred range, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is likely to be obtained, and the storage stability as a resist composition becomes good, which is preferable.

[0313] <Base component (D)> In addition to the component (A), the resist composition of the present embodiment may contain a base component ((D) component) that traps the acid generated by exposure (that is, controls the diffusion of the acid). The component (D) acts as a quencher (acid diffusion controller) that traps the acid generated by exposure in the resist composition. Examples of the component (D) include a photo-dissociable base (D1) (hereinafter referred to as the “(D1) component”) that decomposes upon exposure and loses acid diffusion control properties, and a nitrogen-containing organic compound (D2) (hereinafter referred to as the “(D2) component”) that does not correspond to the (D1) component. Among these, the photo-dissociable base ((D1) component) is preferable because it is easy to enhance the characteristics of high sensitivity, reduction of roughness, and suppression of the occurrence of coating defects. The forms of containing the (D1) component and the (D2) component may be in the form of a compound, may be in the form incorporated into the (A1) component as the above-described structural unit (a6), or may be in both of these forms. The compound exemplified as the (D1) component described later may be used as the above-described acid generator component ((B) component) in combination with other compounds in some cases.

[0314] ·Regarding the (D1) component (D1) The component is not particularly limited as long as it decomposes upon exposure and loses acid diffusion controllability, and one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-3) component") are preferred. In the exposed portion of the resist film, the (d1-1) to (d1-3) components decompose and lose acid diffusion controllability (basicity), so they do not act as quenchers, and in the unexposed portion of the resist film, they act as quenchers.

[0315] [Chemical formula] [In the formula, Rd 1 ~Rd 4 is an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group. However, it is assumed that a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd 2 in the formula (d1-2). Yd 1 is a single bond or a divalent linking group. m is an integer of 1 or more, and M m+ are each independently an m-valent organic cation.]

[0316] {(d1-1) component} ·· Anion part In the formula (d1-1), Rd 1 is an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group, and examples thereof are the same as those of the above R' 201 . Among these, Rd 1Examples thereof preferably include an aromatic hydrocarbon group which may have a substituent, an alicyclic group which may have a substituent, or a chain alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the general formulas (a2-r-1) to (a2-r-8), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is included as a substituent, it may be via an alkylene group, and in this case, the linking group represented by each of the above formulas (L-al-1) to (L-al-5) is preferable as the substituent. Note that Rd 1 When the aromatic hydrocarbon group, the alicyclic group, or the chain alkyl group in Rd 1 has a linking group represented by each of the general formulas (L-al-1) to (L-al-7) as a substituent, in the general formulas (L-al-1) to (L-al-7), Rd in the formula (d3-1) 101 is such that it is bonded to the carbon atom constituting the aromatic hydrocarbon group, the alicyclic group, or the chain alkyl group in Rd Examples of the aromatic hydrocarbon group preferably include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure composed of a bicyclooctane skeleton and another ring structure). Examples of the alicyclic group preferably include a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, and tetracyclododecane. The linear alkyl group preferably has 1 to 10 carbon atoms. Specifically, examples include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group; branched-chain alkyl groups such as 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0317] When the linear alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atom, sulfur atom, and nitrogen atom.

[0318] Preferred specific examples of the anion part of the component (d1-1) are shown below.

[0319]

Chemical formula

[0320] ··· Cation part In formula (d1-1), M m+ is an m-valent organic cation. As the organic cation of M m+ the same ones as the cations respectively represented by the general formulas (ca-1) to (ca-3) are preferably exemplified, the cation represented by the general formula (ca-1) is more preferable, and the cations respectively represented by the formulas (ca-1-1) to (ca-1-84) are even more preferable. The component (d1-1) may be used alone or in combination of two or more.

[0321] {(d1-2) component} ··Anion part In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and the above R’ 201 is the same as those mentioned above. However, for Rd 2 it is assumed that a fluorine atom is not bonded (not fluorine-substituted) to the carbon atom adjacent to the S atom. Thereby, the anion of the (d1-2) component becomes a moderately weak acid anion, and the quenching ability as the (D) component is improved. As Rd 2 it is preferably a linear alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent, and more preferably an aliphatic cyclic group which may have a substituent.

[0322] As for the linear alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. As for the aliphatic cyclic group, it is a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, etc. (which may have a substituent); and more preferably a group obtained by removing one or more hydrogen atoms from camphor.

[0323] As for the hydrocarbon group of Rd 2 it may have a substituent, and examples of the substituent are the same as those which the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, linear alkyl group) in Rd 1 in the above formula (d1-1) may have.

[0324] Specific preferred examples of the anion part of the (d1-2) component are shown below.

[0325]

Chemical formula

[0326] ··Cation part In formula (d1-2), M m+ is an m-valent organic cation, which is the same as M in the above formula (d1-1). m+ The same applies to the following descriptions. The component (d1-2) may be used alone or in combination of two or more.

[0327] {(d1-3) component} ··Anion part In formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. The same as the above R' 201 is exemplified, and it is preferably a cyclic group, a linear alkyl group, or a linear alkenyl group containing a fluorine atom. Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group of the above Rd 1 is more preferable.

[0328] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. The same as the above R' 201 is exemplified. Among them, it is preferably an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. are exemplified. A part of the hydrogen atoms of the alkyl group of Rd 4 may be substituted with a hydroxyl group, a cyano group, etc. Rd 4The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. 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. Among them, a methoxy group and an ethoxy group are preferred.

[0329] Rd 4 The alkenyl group in is the same as the alkenyl group in the above R'. 201 Examples thereof include the same as the alkenyl group in the above R', and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferred. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0330] Rd 4 The cyclic group in is the same as the cyclic group in the above R'. 201 Examples thereof include the same as the cyclic group in the above R', and an alicyclic group obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, etc., or an aromatic group such as a phenyl group or a naphthyl group is preferred. When Rd 4 is an alicyclic group, the resist composition dissolves well in an organic solvent, and thus the lithography characteristics are good. Also, when Rd 4 is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, and the sensitivity and lithography characteristics are good.

[0331] 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, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a hetero atom, and the like. Each of these is Ya in the above formula (a2-1). 21Examples of the divalent linking group in the description of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as those mentioned above. Yd 1 Preferably, it is a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. As the alkylene group, a linear or branched alkylene group is more preferable, and a methylene group or an ethylene group is even more preferable.

[0332] Specific preferable examples of the anion part of the component (d1-3) are shown below.

[0333]

Chemical formula

[0334]

Chemical formula

[0335] ···Cation part In formula (d1-3), M m+ is an m-valent organic cation, which is the same as M m+ in the above formula (d1-1). The component (d1-3) may be used alone or in combination of two or more.

[0336] The component (D1) may use only any one of the above components (d1-1) to (d1-3), or may use a combination of two or more. When the resist composition contains the component (D1), the content of the component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the component (A).

[0337] The component (D1) preferably contains the above component (d1-1). Among the whole (D1) component, the content of the (d1-1) component is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. The (D1) component may consist only of the compound (d1-1) component.

[0338] Production method of the (D1) component: The production methods of the above-mentioned (d1-1) component and (d1-2) component are not particularly limited and can be produced by known methods. Also, the production method of the (d1-3) component is not particularly limited. For example, it is produced in the same manner as the method described in US2012-0149916. As an example of the base component ((D) component) that traps the acid generated by exposure, the compound of the (D1) component was shown, but the compound of the (D1) component may be used as the (B) component. For example, in the resist composition of the present embodiment, a compound of the (D1) component may be used as the (B) component, and a compound that generates an acid with a lower acidity than the acid generated by exposure of the (D1) component may be used as the (D) component. Also, in the resist composition of the present embodiment, a compound of the (D1) component may be used as the (B) component, and the (D2) component described later may be used as the (D) component.

[0339] ·Regarding the (D2) component As the (D) component, a nitrogen-containing organic compound component that does not correspond to the above (D1) component (hereinafter referred to as the "(D2) component") may be contained. The (D2) component is not particularly limited as long as it acts as an acid diffusion control agent and does not correspond to the (D1) component, and can be arbitrarily used from known ones. Among them, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH3 is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms, or cyclic amines. Specific examples of alkylamines and alkyl alcohol amines 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 alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0340] Examples of cyclic amines include, for example, heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine). Specific examples of aliphatic monocyclic amines include piperidine, piperazine, and the like. As aliphatic polycyclic amines, those having 6 to 10 carbon atoms are preferred, and specific examples include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane, and the like.

[0341] Examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc., and triethanolamine triacetate is preferred.

[0342] Also, as the component (D2), an aromatic amine may be used. Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, 2,6-di-tert-butylpyridine, 2,6-di-tert-butylpyridine, etc.

[0343] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the content of the component (D2) in the resist composition is usually in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). By setting it within the above range, the resist pattern shape, standing time stability, etc. are improved.

[0344] <At least one compound (E) selected from the group consisting of an organic carboxylic acid, an oxo acid of phosphorus and its derivatives> In the resist composition of this embodiment, for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, standing time stability, etc., as an optional component, at least one compound (E) selected from the group consisting of an organic carboxylic acid, an oxo acid of phosphorus and its derivatives (hereinafter referred to as "component (E)") can be contained. Examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. Among them, salicylic acid is preferred. Examples of the oxo acid of phosphorus include phosphoric acid, phosphonic acid, phosphinic acid, etc. Among them, phosphonic acid is particularly preferred.

[0345] In the resist composition of the present embodiment, the component (E) may be used alone or in combination of two or more. When the resist composition contains the component (E), the content of the component (E) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, with respect to 100 parts by mass of the component (A). By setting the content within the above range, the lithography characteristics can be further improved.

[0346] <Fluorine additive component (F)> The resist composition of the present embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and by using it as a resin different from the component (A), the lithography characteristics can be improved. 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. (F) More specifically as the component, a polymer having a structural unit (f1) represented by the following general formula (f1-1) can be mentioned. As this polymer, a polymer (homopolymer) composed only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); It is preferably a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1), and more preferably a copolymer of the structural unit (f1) and the structural unit (a1). Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate and a structural unit derived from 1-methyl-1-adamantyl (meth) acrylate are preferable, and a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate is more preferable.

[0347]

Chemical formula

[0348] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as above. As R, a hydrogen atom or a methyl group is preferable. In formula (f1-1), Rf 102 and Rf 103 As the halogen atom, a fluorine atom is preferable. Rf 102 and Rf 103 As the alkyl group having 1 to 5 carbon atoms, the same ones as the alkyl group having 1 to 5 carbon atoms of the above R can be mentioned, and a methyl group or an ethyl group is preferable. Rf 102 and Rf103 As the alkyl halide group having 1 to 5 carbon atoms, specifically, a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms can be mentioned. As the halogen atom, a fluorine atom is preferable. Among them, Rf 102 and Rf 103 are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom. In formula (f1-1), nf 1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0349] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, preferably having 1 to 20 carbon atoms, more preferably having 1 to 15 carbon atoms, and particularly preferably having 1 to 10 carbon atoms. Further, in the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferably 60% or more are fluorinated because the hydrophobicity of the resist film during immersion exposure increases. 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, -CH2-CH2-CF2-CF2-CF2-CF3.

[0350] (F) component's weight average molecular weight (Mw) (in terms of polystyrene conversion standard by gel permeation chromatography) is preferably from 1,000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. When it is below the upper limit value of this range, there is sufficient solubility in the resist solvent for use as a resist. When it is above the lower limit value of this range, the water repellency of the resist film is good. (F) component's dispersity (Mw / Mn) 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.

[0351] In the resist composition of this embodiment, the (F) component may be used alone or in combination of two or more. When the resist composition contains the (F) component, the content of the (F) component is preferably from 0.5 to 10 parts by mass, more preferably from 1 to 10 parts by mass with respect to 100 parts by mass of the (A) component.

[0352] <Organic solvent component (S)> The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as the "(S) component"). In the resist composition of this embodiment, the (S) component may be used alone or as a mixed solvent of two or more. Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate, and cyclohexanone are preferred.

[0353] Also, as the (S) component, a mixed solvent of PGMEA and a polar solvent is also preferred. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent. As the (S) component, a mixed solvent of at least one selected from PGMEA and ethyl lactate and γ-butyrolactone is also preferred. In this case, the mixing ratio is preferably such that the mass ratio of the former to the latter is from 70:30 to 95:5. (S) The amount used is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0354] In the resist composition of this embodiment, after dissolving the above resist material in the component (S), impurities and the like may be removed using a polyimide porous membrane, a polyamideimide porous membrane, or the like. For example, filtration of the resist composition may be performed using a filter made of a polyimide porous membrane, a filter made of a polyamideimide porous membrane, a filter made of a polyimide porous membrane and a polyamideimide porous membrane, or the like. Examples of the polyimide porous membrane and the polyamideimide porous membrane include those described in JP-A-2016-155121.

[0355] The resist composition of this embodiment described above contains a component (A1) having a structural unit (a0) derived from a compound represented by the general formula (a0-m0). By containing the component (A1) having the structural unit (a0), the resist composition of this embodiment can achieve high sensitivity and has the effect of improving lithography characteristics such as LWR and EL. The reason for such an effect is presumed as follows. Since the cationic part of the structural unit (a0) has a structure in which the distance between the sulfur atom center in the formula (a0-m0) and the iodine atom having high light absorption efficiency in exposure such as EUV is short, the electrons generated by exposure efficiently contribute to the decomposition of the cation. Therefore, in the resist composition of this embodiment, high sensitivity can be achieved and roughness is reduced. In addition, since the structural unit (a0) is a polymer component, the uniformity of the acid generator component and the acid diffusion inhibitor component in the resist film is improved, and a cation decomposition product (low molecular component) containing a highly hydrophobic iodine atom that leads to development inhibition is less likely to be generated in the film. Therefore, in the resist composition of this embodiment, roughness is reduced. Furthermore, since the constitutional unit (a0) is a polymer component, the proportion of the low-molecular component having an iodine atom with a large molecular size decreases, and the rigidity of the resist film is maintained. Therefore, the resist composition of the present embodiment has a wide EL. It is presumed that by the synergistic action of the above-described respective effects, the resist composition of the present embodiment can achieve high sensitivity and improve lithography characteristics such as LWR and EL.

[0356] (Resist pattern forming method) The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern. As an embodiment of such a resist pattern forming method, for example, a resist pattern forming method performed as follows can be mentioned.

[0357] First, the resist composition of the above-described embodiment is applied onto a support with a spinner or the like, and a bake (post-apply bake (PAB)) treatment is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, selective exposure is performed on the resist film by, for example, exposure through a mask (mask pattern) having a predetermined pattern formed thereon or direct irradiation with an electron beam without using a mask pattern using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus. Then, a bake (post-exposure bake (PEB)) treatment is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds. Next, the resist film is developed. In the case of an alkali development process, an alkali developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic-based developer) is used.

[0358] After the development process, preferably a rinsing process is performed. In the case of an alkaline development process, water rinsing with pure water is preferred, and in the case of a solvent development process, it is preferable to use a rinsing solution containing an organic solvent. In the case of a solvent development process, after the development process or the rinsing process, a process of removing the developer or the rinsing solution adhering to the pattern with a supercritical fluid may be performed. After the development process or the rinsing process, drying is performed. Also, in some cases, a baking process (post-bake) may be performed after the above development process.

[0359] The support is not particularly limited, and conventionally known ones can be used. For example, substrates for electronic components, those with a predetermined wiring pattern formed thereon, etc. can be mentioned. More specifically, silicon wafers, metal substrates such as copper, chromium, iron, aluminum, and glass substrates can be mentioned. As materials for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

[0360] The wavelength used for exposure is not particularly limited, and it can be performed using 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 pattern forming method of the present embodiment is particularly useful for a method of exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0361] The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (Liquid Immersion Lithography). Liquid immersion exposure is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled with a solvent (liquid immersion medium) having a refractive index greater than that of air in advance, and exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed is preferable. Examples thereof include water, fluorine-based inert liquids, silicon-based solvents, hydrocarbon-based solvents, and the like. Water is preferably used as the immersion medium.

[0362] Examples of the alkaline developer used for development in the alkaline development process include an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used for development in the solvent development process may be any one that can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents can be mentioned.

[0363] Examples of the ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0364] Examples of the nitrile-based solvents include acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like.

[0365] Known additives can be incorporated into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, and for example, ionic or non-ionic fluorine-based and / or silicon-based surfactants can be used.

[0366] The development process can be carried out by known development methods. For example, a method of immersing a support in a developer for a certain period of time (dip method), a method of raising the developer on the surface of the support by surface tension and allowing it to stand for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), a method of continuously discharging the developer while scanning a developer discharge nozzle at a constant speed on a support rotating at a constant speed (dynamic dispense method), etc. can be mentioned.

[0367] As the organic solvent contained in the rinse liquid used for the rinse treatment after the development process in the solvent development process, for example, among the organic solvents mentioned as the organic solvent used for the organic developer, those that are less likely to dissolve the resist pattern can be appropriately selected and used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination of two or more. They may also be used in mixture with organic solvents other than those described above or water.

[0368] The rinse treatment (cleaning treatment) using the rinse liquid can be carried out by known rinse methods. Examples of the method of this rinse treatment include a method of continuously discharging the rinse liquid on a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), a method of spraying the rinse liquid on the surface of the support (spray method), etc.

[0369] According to the resist pattern forming method of the present embodiment described above, since the resist composition described above is used, it is possible to achieve high sensitivity and form a resist pattern with improved lithography characteristics such as LWR and EL.

[0370] In the resist composition of the above-described embodiment and various materials used in the pattern forming method of the above-described embodiment (for example, resist solvent, developer, rinse liquid, antireflection film forming composition, top coat forming composition, etc.), it is preferable that they do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, components containing sulfur atoms or phosphorus atoms. Here, examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. As the content of impurities contained in these materials, 200 ppb or less is preferable, 1 ppb or less is more preferable, 100 ppt (parts per trillion) or less is still more preferable, 10 ppt or less is particularly preferable, and it is most preferable that they are substantially not contained (being below the detection limit of the measuring device).

[0371] (Compound) The compound according to the third aspect of the present invention is a compound represented by the following general formula (a0-m0) (hereinafter, also referred to as "compound (a0-m0)").

[0372] [Chemical formula] [In the formula, W 0 is a polymerizable group-containing group. Y 0 is a single bond or a divalent linking group. R 01 is an arylene group which may have a substituent, an alkylene group which may have a substituent, or an alkenylene group which may have a substituent. R 02 and R 03 are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R 02 and R 03 may be bonded to each other to form a ring together with the sulfur atom in the formula. However, one or more of R 01 to R 03 have at least one iodine atom as a substituent. X - is a counter anion.]

[0373] In the formula, W 0 , Y 0 , R 01 , R 02 , R 03 and X - are the same as W 0 , Y 0 , R 01 , R 02 , R 03 and X - in the general formula (a0-m0) in the above-mentioned <<structural unit (a0)>>.

[0374] The compound (a0-m0) is preferably a compound represented by the following general formula (a0-m1). [Chemical formula] [In the formula, W 0 is a polymerizable group-containing group. Y 0 is a single bond or a divalent linking group. Ar 01 ~Ar 03 are each independently an aromatic ring which may have a substituent. However, one or more of Ar 01 ~Ar 03 have at least one iodine atom. The aromatic rings in Ar 01 ~Ar 03 may each have a substituent other than iodine. Ar 02 and Ar 03 may be bonded to each other to form a ring together with the sulfur atom in the formula. X - is a counter anion.]

[0375] In the formula, W 0 , Y 0 , Ar 01 ~Ar 03 and X - are the same as W 0 , Y 0 , Ar 01 , Ar 02 , Ar 03 and X - in the general formula (a0-m1) in the above-mentioned <<structural unit (a0)>>.

[0376] The compound of this embodiment is the same as the compound that induces the structural unit (a0) possessed by the component (A1) of the resist composition according to the first aspect.

[0377] <Method for producing compound> The compound (a0-m0) can be produced by appropriately combining known methods, as in the <Compound Synthesis Example> shown in [Examples] described later. The compound (a0-m0) can be produced, for example, by the following reactions (I) to (II).

[0378] ≪Reaction (I)≫ By reacting the compound (a0pre1-m0) with the compound (a0pre2-m0), the compound (a0pre3-m0) is obtained. Subsequently, by anion-exchanging the methanol solution of the compound (a0pre3-m0) with a strong base ion exchange resin, the compound (a0pre4-m0) is obtained.

[0379]

Chemical formula

[0380] The temperature condition of Reaction (I) is, for example, 0 to 50 °C, and the reaction time of Reaction (I) is, for example, 10 minutes or more and 24 hours or less.

[0381] Examples of the reaction solvent for Reaction (I) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, dimethyl sulfoxide, and the like.

[0382] ≪Reaction (II)≫ Compound (a0-m0) is obtained by the salt exchange reaction of compound (a0pre4-m0) and compound (a0pre5-m0).

[0383] [Chemical formula] [wherein, W 0 , Y 0 , R 01 ~R 03 and X - are the same as those in the above formula (a0-m0), respectively.]

[0384] The temperature condition of reaction (II) is, for example, 0 to 50 °C, and the reaction time of reaction (II) is, for example, 10 minutes or more and 24 hours or less.

[0385] Examples of the reaction solvent used in reaction (II) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, dimethyl sulfoxide, and the like.

[0386] In the above-described method for producing compound (a0-m0), after each reaction is completed, the compound in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be appropriately combined and used. The structure of the compound obtained as described above can be identified by general organic analysis methods such as 1H-nuclear magnetic resonance (NMR) spectroscopy and 13C-NMR spectroscopy. As the raw materials used in each step, commercially available ones may be used, or synthesized ones may be used.

[0387] The compound of the present embodiment described above can be used in the production of the resist composition according to the first aspect. Further, the compound of the present embodiment can be used in the production of the polymer compound according to the fourth aspect described later.

[0388] (Polymer compound) The polymer compound according to the fourth aspect of the present invention has a structural unit (a0) derived from the compound represented by the general formula (a0-m0). The structural unit (a0) is the same as that described above. The polymer compound according to the fourth aspect is the same as the component (A1) described above. The polymer compound according to the fourth aspect is a polymer compound having a structural unit derived from the compound (a0-m0) according to the third aspect. The polymer compound of the present embodiment can be used for the production of the resist composition according to the first aspect. By incorporating the polymer compound of the present embodiment into a resist composition, high sensitivity can be achieved, lithography characteristics such as roughness reduction can be further improved, and a wide EL can be obtained.

Examples

[0389] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0390] <Synthesis Example of Compound> (Synthesis Example of Compound (a0-mb-1)) 13.6 g of compound (b-a-1), 2.3 g of methacrylic acid chloride, and 2.4 g of triethylamine (TEA) were stirred in 60 g of acetonitrile at room temperature for 2 hours. 100 g of dichloromethane and 50 g of water were added, and after stirring at room temperature, the organic layer was recovered and the solvent was distilled off. The obtained residue was purified by crystallization repeatedly to obtain 11.7 g of compound (mb-1-a) (yield 78%). The methanol solution of compound (mb-1-a) was anion-exchanged with a strong base ion exchange resin to obtain a compound (mb-1-b) solution.

[0391]

Chemical Formula

[0392] To a solution of compound (mb-1-b), 12.4 g of compound (b-c-1), 100 g of dichloromethane, and 50 g of water were added, and the mixture was stirred at room temperature. The organic layer was recovered, washed repeatedly with water, and then the solvent was distilled off and dried to obtain 22.4 g of the above-mentioned compound (a0-mb-1) (yield 90%).

[0393]

Chemical formula

[0394] (Synthesis examples of compounds (a0-mb-2) to (a0-mb-5) and (a0-mb-11)) Except that compound (b-a-1) was replaced with the following compounds (b-a-2) to (b-a-5) and (b-a-11) respectively, the above-mentioned compounds (a0-mb-2) to (a0-mb-5) and (a0-mb-11) were obtained respectively by the same method as the above (synthesis example of compound (a0-mb-1)).

[0395]

Chemical formula

[0396]

Chemical formula

[0397] (Synthesis example of compound (a0-mb-6)) 12.0 g of compound (b-a-3), 3.3 g of compound (b-b-1), and 2.8 g of diisopropylcarbodiimide were stirred in 60 g of acetonitrile at room temperature for 2 hours. 100 g of dichloromethane and 50 g of water were added, and after stirring at room temperature, the organic layer was recovered and the solvent was distilled off. The obtained residue was repeatedly purified by crystallization to obtain 9.5 g (yield 65%) of compound (mb-6-a). The subsequent steps were carried out in the same manner as the above (synthesis example of compound (a0-mb-1)) to obtain the above-mentioned compound (a0-mb-6).

[0398]

Chemical formula

[0399]

Chem.

[0400] (Synthesis Examples of Compounds (a0-mb-7), (a0-mb-8) and (a0-mb-12)) The above-mentioned compounds (a0-mb-7), (a0-mb-8) and (a0-mb-12) were obtained respectively in the same manner as in the above (Synthesis Example of Compound (a0-mb-6)), except that the following compounds (b-b-2) to (b-b-4) were used respectively instead of compound (b-b-1).

[0401]

Chem.

[0402]

Chem.

[0403] (Synthesis Examples of Compounds (a0-mb-9) and (a0-mb-10)) Compounds (a0-mb-9) and (a0-mb-10) were obtained respectively in the same manner as in the above (Synthesis Example of Compound (a0-mb-1)), except that the following compounds (b-c-2) and (b-a-3) were used respectively instead of compound (b-c-1).

[0404]

Chem.

[0405]

Chem.

[0406] (Synthesis Examples of Compounds (a0-md-1) to (a0-md-8), (a0-md-12) and (a0-md-13)) Except for using the following compound (d-c-1) instead of compound (b-c-1), the above-mentioned compounds (a0-md-1) to (a0-md-8), (a0-md-12), and (a0-md-13) were obtained in the same manner as in the above (Synthesis Example of Compound (a0-mb-1)) to (Synthesis Example of Compound (a0-mb-8)), (Synthesis Example of Compound (a0-mb-11)), and (Synthesis Example of Compound (a0-mb-12)), respectively.

[0407]

Chemical formula

[0408]

Chemical formula

[0409] (Synthesis Examples of Compounds (a0-md-9) to (a0-md-11)) Except for using the following compounds (d-c-2) to (d-c-4) instead of compound (b-c-1), the above-mentioned compounds (a0-md-9) to (a0-md-11) were obtained in the same manner as in the above (Synthesis Example of Compound (a0-mb-1)).

[0410]

Chemical formula

[0411]

Chemical formula

[0412] NMR measurements were performed on the obtained compounds (a0-mb-1) to (a0-mb-12) and (a0-md-1) to (a0-md-13), and their structures were identified from the analysis results shown below.

[0413] Compound (a0-mb-1): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 8.2 (m, -Ar, 6H), 7.8 (d, -Ar, 1H), 7.6 (d, -Ar, 4H), 7.3 (d, -Ar, 2H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0414] Compound (a0-mb-2): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 8.1 (d, -Ar, 1H), 7.9 - 7.8 (m, -Ar, 12H), 7.4 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0415] Compound (a0-mb-3): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 7.9 (d, -Ar, 4H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0416] Compound (a0-mb-4): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 8.0 - 7.9 (m, -Ar, 6H), 7.8 (s + s, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0417] Compound (a0-mb-5): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (m, -Ar, 4H), 8.2 (m, -Ar, 2H), 7.9 (m, -Ar, 2H), 7.8 (s + s, -Ar, 2H), 7.7 (m, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0418] Compound (a0-mb-6): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 7.9 (m, -Ar, 6H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.4 (d, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.7 (dd, -Ar, 1H), 5.8 (d, -Ar, 1H), 5.4 (d, -Ar, 1H), 4.7 (t, -CH2-, 2H)

[0419] Compound (a0-mb-7): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 10.8 (s, -OH, 1H), 8.4 (s + s, -Ar, 2H), 7.9 (d, -Ar, 4H), 7.8 (s + s, -Ar, 2H), 7.7 (m, -Ar, 5H), 7.6 (d, -Ar, 1H), 7.3 (d, -Ar, 1H), 7.0 (d, -Ar, 1H), 6.7 (dd, -Ar, 1H), 5.7 (d, -Ar, 1H), 5.2 (d, -Ar, 1H), 4.7 (t, -CH2-, 2H)

[0420] Compound (a0-mb-8): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 8.3 (s, -Ar, 1H), 7.9 (m, -Ar, 5H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.3 (s + s, -Ar, 2H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0421] Compound (a0-mb-9): 1H-NMR (dmso-d6, 400 MHz): δ(ppm) = 8.4 (s, -Ar, 1H), 7.9 (d, -Ar, 4H), 7.8 (s, -Ar, 1H), 7.7 (d, -Ar, 4H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.5 (t, -CH2-, 2H), 2.0 (m, -CH, 3H), 1.9 (s, -CH3, 3H), 1.8 (m, -CH2-, 6H), 1.7 (m, -CH2-, 6H)

[0422] Compound (a0-mb-10): 1H-NMR (dmso-d6, 400 MHz): δ(ppm) = 8.4 (s, -Ar, 1H), 7.9 (d, -Ar, 4H), 7.8 (s, -Ar, 1H), 7.7 (d, -Ar, 4H), 7.4 (m, -Ar, 1H), 7.3 (m, -Ar, 3H), 7.2 (m, -Ar, 1H), 7.1 - 7.0 (m, -Ar, 4H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (s, -CH2-, 1H), 4.6 - 4.3 (m, -CH2-, 3H), 3.0 (m, -CH, 1H), 2.0 (m, -CH, 1H), 1.9 (m, -CH, 1H), 1.9 (s, -CH3, 3H)

[0423] Compound (a0-mb-11): 1H-NMR (dmso-d6, 400 MHz): δ(ppm) = 8.5 (m, -Ar, 2H), 8.4 (m, -Ar, 4H), 8.0 (m, -Ar, 2H), 7.8 (s + s, -Ar, 2H), 7.7 (m, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 4.7 (t, -CH2-, 2H), 1.9 (s, -CH3, 3H)

[0424] Compound (a0-mb-12): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 8.0 (d, -Ar, 2H), 7.9 (d, -Ar, 4H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.5 (d, -Ar, 2H), 7.3 (d, -Ar, 1H), 7.2 (s, -CH=CH-, 2H), 4.7 (t, -CH2-, 2H)

[0425] Compound (a0-md-1): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 8.2 (m, -Ar, 6H), 7.8 (d, -Ar, 1H), 7.6 (d, -Ar, 4H), 7.3 (d, -Ar, 2H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0426] Compound (a0-md-2): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 8.1 (d, -Ar, 1H), 7.9 - 7.8 (m, -Ar, 12H), 7.4 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0427] Compound (a0-md-3): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 7.9 (d, -Ar, 4H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0428] Compound (a0-md-4): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 8.0 - 7.9 (m, -Ar, 6H), 7.8 (s + s, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0429] Compound (a0-md-5): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (m, -Ar, 4H), 8.2 (m, -Ar, 2H), 7.9 (m, -Ar, 2H), 7.8 (s + s, -Ar, 2H), 7.7 (m, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0430] Compound (a0-md-6): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 7.9 (m, -Ar, 6H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.4 (d, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.7 (dd, -Ar, 1H), 5.8 (d, -Ar, 1H), 5.4 (d, -Ar, 1H),

[0431] Compound (a0-md-7): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 10.8 (s, -OH, 1H), 8.4 (s + s, -Ar, 2H), 7.9 (d, -Ar, 4H), 7.8 (s + s, -Ar, 2H), 7.7 (m, -Ar, 5H), 7.6 (d, -Ar, 1H), 7.3 (d, -Ar, 1H), 7.0 (d, -Ar, 1H), 6.7 (dd, -Ar, 1H), 5.7 (d, -Ar, 1H), 5.2 (d, -Ar, 1H),

[0432] Compound (a0-md-8): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 8.3 (s, -Ar, 1H), 7.9 (m, -Ar, 5H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.3 (s + s, -Ar, 2H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0433] Compound (a0-md-9): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 7.9 (d, -Ar, 4H), 7.8 (s, -Ar, 1H), 7.7 (m, -Ar, 5H), 7.3 (d, -Ar, 1H), 7.1 (m, -Ar, 1H), 6.6 (m, -Ar, 2H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0434] Compound (a0-md-10): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 7.9 (d, -Ar, 4H), 7.8 (s, -Ar, 1H), 7.7 (d, -Ar, 4H), 7.3 (m, -Ar, 4H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0435] Compound (a0-md-11): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s, -Ar, 1H), 8.2 (s, -Ar, 1H), 8.0 (s, -Ar, 1H), 7.9 (d, -Ar, 4H), 7.8 (s, -Ar, 1H), 7.7 (d, -Ar, 4H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0436] Compound (a0-md-12): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.5 (m, -Ar, 2H), 8.4 (m, -Ar, 4H), 8.0 (m, -Ar, 2H), 7.8 (s + s, -Ar, 2H), 7.7 (m, -Ar, 2H), 7.3 (d, -Ar, 1H), 6.1 (s, -CH2, 1H), 5.7 (s, -CH2, 1H), 1.9 (s, -CH3, 3H)

[0437] Compound (a0-md-13): 1H-NMR (dmso-d6, 400 MHz): δ (ppm) = 8.4 (s + s, -Ar, 2H), 8.0 (d, -Ar, 2H), 7.9 (d, -Ar, 4H), 7.8 (s + s, -Ar, 2H), 7.7 (d, -Ar, 4H), 7.5 (d, -Ar, 2H), 7.3 (d, -Ar, 1H), 7.2 (s, -CH=CH-, 2H)

[0438] <Production of Polymer Compound> (Synthesis of Polymer Compound (A1-1)) 14.9 g of Compound (a0-mb-1), 6.7 g of Compound (m10pre-1), 8.9 g of Compound (m1pre-1), and 1.9 g of 2,2'-Azobis(2-methylpropionitrile) (V-601) as a polymerization initiator were dissolved in a mixed solvent of 50 g of MEK (methyl ethyl ketone) and 50 g of GBL (gamma-butyrolactone), heated to 80 °C under a nitrogen atmosphere, and stirred for 6 hours. Then, 4.0 g of trifluoroacetic acid and 60 g of isobutanol were added to the reaction solution, and the mixture was stirred at 30 °C for 18 hours. After completion of the reaction, the obtained reaction solution was dropped into 600 g of heptane to precipitate the product. The obtained white solid was dissolved in MEK and purified by repeating reprecipitation into heptane to obtain 15.4 g of the target polymer compound (A1-1).

[0439]

Chemical Structure

[0440] (Synthesis of Polymer Compounds (A1-2) to (A1-36)) Polymer compounds (A1-2) to (A1-36) were each synthesized in the same manner as the synthesis of polymer compound (A1-1), except that the compounds used in the polymerization reaction were changed.

[0441] Polymer compounds (A1-1) to (A1-36) are shown below. In the following formula, l, m, n, and o represent the composition ratios (molar ratios) of the respective structural units.

[0442]

Chemical Structure

[0443] [Chemistry]

[0444] [Chemistry]

[0445] [Chemistry]

[0446] [Chemistry]

[0447] [Chemistry]

[0448] [Chemistry]

[0449] [Chemistry]

[0450] (Synthesis of Polymer Compounds (A2-1) to (A2-5) of Comparative Examples) Polymer compounds (A2-1) to (A2-5) were synthesized in the same manner as the synthesis of polymer compound (A1-1), except that the compounds used in the polymerization reaction were changed.

[0451] Polymer compounds (A2-1) to (A2-5) are shown below. In the following formulas, l, m, and n represent the composition ratios (molar ratios) of the respective structural units.

[0452] [Chemistry]

[0453] For the obtained polymer compounds (A1-1) to (A1-36) and (A2-1) to (A2-5), the weight average molecular weight (Mw) and the molecular weight dispersity (Mw / Mn) were determined by GPC measurement (in terms of standard polystyrene), respectively. Also, for the polymer compounds (A1-1) to (A1-36) and (A2-1) to (A2-5), the copolymer composition ratio (the ratio of each structural unit in the structural formula (molar ratio)) was determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz, 13 C-NMR). The results are shown in Tables 1 to 3.

[0454]

Table 1

[0455]

Table 2

[0456]

Table 3

[0457]

Chemical formula

[0458]

Chemical formula

[0459] <Preparation of resist composition> (Examples 1 to 36, Comparative Examples 1 to 5) The resist compositions of each example were prepared by mixing and dissolving the components shown in Tables 4 to 6, respectively.

[0460]

Table 4

[0461] [Table 5]

[0462] [Table 6]

[0463] In Tables 4 to 6, each abridged notation has the following meaning respectively. The numerical value in [ ] is the blending amount (parts by mass). (A1)-1 to (A1)-36: The above-mentioned polymer compounds (A1-1) to (A1-36). (A2)-1 to (A2)-5: The above-mentioned polymer compounds (A2-1) to (A2-5).

[0464] (B1)-1: An acid generator composed of the following compound (B1-1).

[0465] [Chemical formula]

[0466] (D1)-1: An acid diffusion control agent composed of the following compound (D1-1).

[0467] [Chemical formula]

[0468] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 20 / 80 (mass ratio).

[0469] [Formation of resist pattern] Step of forming a resist film: On an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS), each resist composition was applied using a spinner, and pre-baked (PAB) at a temperature of 110 °C for 60 seconds on a hot plate and dried to form a resist film with a thickness of 60 nm.

[0470] Step of exposing the resist film: Next, with respect to the resist film, using an electron beam lithography apparatus JEOL-JBX-9300FS (manufactured by JEOL Ltd.), drawing (exposure) was performed at an acceleration voltage of 100 kV with a target size of a 1:1 line and space pattern with a line width of 35 nm (hereinafter referred to as "LS pattern"). Thereafter, post-exposure bake (PEB) treatment was performed at 100°C for 60 seconds.

[0471] Step of developing the exposed resist film: Next, at 23°C, using an aqueous solution of 2.38 mass% tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.), alkali development was performed for 60 seconds. Thereafter, water rinsing was performed for 15 seconds using pure water. As a result, a 1:1 LS pattern with a line width of 35 nm was formed.

[0472] [Evaluation of Optimal Exposure Dose (Eop)] The optimal exposure dose Eop (μC / cm 2 ) at which the LS pattern of the target size is formed by the above <Formation of Resist Pattern> was obtained. This is shown in Tables 7 to 9 as "Eop (μC / cm 2 )".

[0473] [Evaluation of LWR (Line-Width Roughness)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, which is a measure indicating LWR, was obtained. This is shown in Tables 7 to 9 as "LWR (nm)". "3σ" indicates three times the standard deviation (σ) value (3σ) (unit: nm) obtained from the measurement results by measuring the line positions 400 times in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the value of 3σ, the smaller the roughness of the line sidewall, which means that an LS pattern with a more uniform width was obtained.

[0474] [Evaluation of Exposure Margin (EL)] In the above [Evaluation of Optimal Exposure Dose (Eop)], taking the exposure dose at which the space width becomes 35 nm × 105% as E(+) and the exposure dose at which the space width becomes 35 nm × 95% as E(-), the exposure margin (EL(5%)) was calculated as a measure of dimensional change due to exposure dose by the following formula. The results are shown in Tables 7 to 9 as "EL(5%)". EL(5%) = (|E(+) - E(-)| / Eop) × 100 Note that the larger the value of EL, the smaller the dimensional change due to exposure dose, meaning that it is easier to obtain the LS pattern of the target space width.

[0475] [Table 7]

[0476] [Table 8]

[0477] [Table 9]

[0478] As shown in Tables 7 to 9, it was confirmed that the resist compositions of Examples 1 to 36 achieved higher sensitivity and improved lithography characteristics such as LWR and EL compared to the resist compositions of Comparative Examples 1 to 5.

Claims

Claim 1 A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, containing a resin component (A1) whose solubility in a developer changes due to the action of the acid, wherein the resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m0). The resist composition. 【Chemical Formula 1】 [wherein, W ０ is a polymerizable group-containing group. Y ０ is a single bond or a divalent linking group. R ０１ is an arylene group which may have a substituent, an alkylene group which may have a substituent, or an alkenylene group which may have a substituent. R ０２ and R ０３ are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R ０２ and R ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, one or more of R ０１ to R ０３ have at least one iodine atom as a substituent. X － is a counter anion.] Claim 2 R in the general formula (a0 - m0) ０１ The resist composition according to claim 1, which has at least one iodine atom. Claim 3 The resist composition according to claim 1 or 2, wherein the structural unit (a0) is a structural unit derived from a compound represented by the following general formula (a0-m1). 【Chemical 2】 [In the formula, W ０ is a polymerizable group-containing group. Y ０ is a single bond or a divalent linking group. Ar ０１ to Ar ０３ are each independently an aromatic ring which may have a substituent. However, one or more of Ar ０１ to Ar ０３ have at least one iodine atom. The aromatic rings in Ar ０１ to Ar ０３ may each have a substituent other than iodine. Ar ０２ and Ar ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. X － is a counter anion.] Claim 4 A resist pattern forming method having a step of forming a resist film using the resist composition according to claim 1 on a support, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern. Claim 5 A compound represented by the following general formula (a0-m0). 【Chemical Formula 3】 [In the formula, W ０ is a polymerizable group-containing group. Y ０ is a single bond or a divalent linking group. R ０１ is an arylene group which may have a substituent, an alkylene group which may have a substituent, or an alkenylene group which may have a substituent. R ０２ and R ０３ are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R ０２ and R ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, one or more of R ０１ to R ０３ have at least one iodine atom as a substituent. X － is a counter anion.] Claim 6 R in the general formula (a0 - m0) above ０１ is a compound according to claim 5, having at least one iodine atom. Claim 7 The compound according to claim 5 or 6, represented by the following general formula (a0-m1). 【Chemical Formula 4】 [Wherein, W ０ is a polymerizable group-containing group. Y ０ is a single bond or a divalent linking group. Ar ０１ to Ar ０３ are each independently an aromatic ring which may have a substituent. However, Ar ０１ to Ar ０３ in one or more of them have at least one iodine atom. The aromatic rings in Ar ０１ to Ar ０３ may each have a substituent other than iodine. Ar ０２ and Ar ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. X － is a counter anion. ] Claim 8 A polymer compound having a structural unit (a0) derived from a compound represented by the following general formula (a0-m0). 【Chemical Formula 5】 [In the formula, W ０ is a polymerizable group-containing group. Y ０ is a single bond or a divalent linking group. R ０１ is an arylene group which may have a substituent, an alkylene group which may have a substituent, or an alkenylene group which may have a substituent. R ０２ and R ０３ are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R ０２ and R ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, one or more of R ０１ to R ０３ have at least one iodine atom as a substituent. X － is a counter anion.] Claim 9 R in the general formula (a0 - m0) ０１ is a polymer compound according to claim 8 having at least one iodine atom. Claim 10 The polymer compound according to claim 8 or 9, which is a structural unit derived from a compound represented by the following general formula (a0-m1). 【Chemical Formula 6】 [In the formula, W ０ is a polymerizable group-containing group. Y ０ is a single bond or a divalent linking group. Ar ０１ to Ar ０３ are each independently an aromatic ring which may have a substituent. However, one or more of Ar ０１ to Ar ０３ have at least one iodine atom. The aromatic rings in Ar ０１ to Ar ０３ may each have a substituent other than iodine. Ar ０２ and Ar ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. X － is a counter anion.]

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