Resist Composition and Resist Pattern Forming Method

Abstract

To provide a resist composition which achieves higher sensitivity and can reduce roughness of a resist pattern, and a resist pattern forming method.SOLUTION: The resist composition which generates an acid upon exposure and whose solubility in a developer changes by the action of an acid contains: a resin component whose solubility in a developer changes by the action of an acid; and a photodegradable base which controls diffusion of an acid generated upon exposure. The resin component has a constituent unit represented by general formula (a0-1). The photodegradable base has an anionic moiety and a cationic moiety, and the LUMO energy of the cationic moiety is -4.70 eV or less. In the general formula (a0-1), R01 represents a hydrogen atom or a C1-5 alkyl group; Ya01 represents a single bond or a divalent linking group; Ar represents a benzene ring or a naphthalene ring; m01 represents an integer of 0-6; and n01 represents an integer of 1-4.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] In recent years, in the manufacture 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 the formation of a resist pattern, the behavior of the acid generated from the acid generator component upon exposure is regarded as one factor that greatly affects lithography characteristics. On the other hand, a chemically amplified resist composition having, together with the acid generator component, an acid diffusion controller that controls the diffusion of the acid generated from the acid generator component upon exposure has been proposed.

[0005] For example, Patent Document 1 discloses a resist composition containing a resin component whose solubility in a developer changes by the action of an acid, an acid generator component, and a photoreactive quencher having a cationic part with a specific structure as an acid diffusion controller.

[0006] This photoreactive quencher is a component that causes an ion exchange reaction with the acid generated from the acid generator component to exhibit a quenching effect. By blending such a photoreactive quencher, the diffusion of the acid generated from the acid generator component from the exposed portion to the unexposed portion of the resist film is controlled, and improvement in lithography characteristics is attempted.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] With the further progress of lithography technology and the increasing miniaturization of resist patterns, for example, in lithography using electron beams or EUV, the formation of fine patterns with a size of several tens of nm is targeted. As the resist pattern size becomes smaller, the resist composition is required to further improve lithography characteristics such as higher sensitivity to the exposure light source and reduction of roughness. However, in the conventional resist compositions as described above, there is room for improvement in terms of higher sensitivity and the effect of reducing roughness with respect to the required characteristics as described above.

[0009] 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 higher sensitivity and reducing the roughness of a resist pattern, and a method for forming a resist pattern using the resist composition.

Means for Solving the Problems

[0010] 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, the resist composition containing a resin component (A1) whose solubility in a developer changes by the action of the acid, and a photo-disintegrating base (D0) that controls the diffusion of the acid generated upon exposure, the resin component (A1) having a structural unit (a0) represented by the following general formula (a0-1), the photo-disintegrating base (D0) having an anion part and a cation part, and the energy of the LUMO of the cation part being -4.70 eV or less.

[0011] [Chemical formula] [In the formula, R 01 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Ya 01 is a single bond or a divalent linking group. Ar is a benzene ring or a naphthalene ring. m01 is an integer of 0 to 6. n01 is an integer of 1 to 4 as long as the valence allows.]

[0012] A second aspect of the present invention is a resist pattern forming method having 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. [Advantages of the Invention]

[0013] According to the present invention, it is possible to provide a resist composition capable of achieving high sensitivity and reducing the roughness of a resist pattern, and a resist pattern forming method using the resist composition. [Modes for Carrying Out the Invention]

[0014] 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" shall include linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in an alkoxy group. "Alkylene group" shall include 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 high molecular 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 (-CH 2 -) with a divalent group. "Exposure" is a concept that includes all irradiations of radiation.

[0015] "Base material component" is an organic compound having a film-forming ability. The organic compounds used as the base material component are roughly classified into non-polymers and polymers. As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. In the following, when referring to a "low molecular compound", it means a non-polymer having a molecular weight of 500 or more and less than 4000. As the polymer, those having a molecular weight of 1000 or more are usually used. In the following, when referring to "resin", "high molecular compound" or "polymer", it means 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.

[0016] "Derived constituent unit" means a constituent unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In "acrylic ester", the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R αx ) that substitutes the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom. Further, itaconic acid diester in which the substituent (R αx ) is substituted with a substituent containing an ester bond, and the substituent (R αxIt shall also include α-hydroxyacrylic esters substituted with a hydroxyalkyl group or a group obtained by modifying its hydroxyl group. Note that, unless otherwise specified, the α-carbon atom of the acrylic acid ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom is substituted with a substituent may be referred to as an α-substituted acrylic acid ester.

[0017] The term "derivative" refers to a concept including those in which the hydrogen atom at the α-position of the target compound is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Examples of those derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound, which may have the hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; those in which a substituent other than a hydroxyl group is bonded to the target compound, which may have the hydrogen atom at the α-position substituted with a substituent, and the like. Note that, unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include the same ones as αx R.

[0018] In this specification and the claims of this patent, depending on the structure represented by a chemical formula, there may be asymmetric carbon atoms, 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.

[0019] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility in a developer changes due to the action of the acid. It contains a base component (hereinafter also referred to as "(D) component") that traps the acid generated upon exposure (that is, controls the diffusion of the acid) and a substrate component (hereinafter also referred to as "(A) component") whose solubility in a developer changes due to the action of the acid.

[0020] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, acid is generated in the exposed portion of the resist film, and the solubility of the (A) component 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 the (A) component 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 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 resist pattern.

[0021] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Further, the resist composition of this embodiment may be for an alkali development process using an alkali developer for the development treatment at the time of forming a resist pattern, or may be for a solvent development process using a developer containing an organic solvent (organic-based developer) for the development treatment.

[0022] <Base material component: (A) component> In the resist composition of this embodiment, the (A) component contains a resin component (A1) (hereinafter also referred to as the "(A1) component") whose solubility in the developer changes due to the action of acid. By using the (A1) component, the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in the alkali development process but also in the solvent development process. As the (A) component, at least the (A1) component is used, and other high molecular compounds and / or low molecular compounds may be used in combination with the (A1) component.

[0023] When applying an alkali development process, the substrate component containing the (A1) component is poorly soluble in an alkali developer before exposure. When acid is generated by exposure, the polarity increases due to the action of the acid, and the solubility in the alkali developer increases. Therefore, in the formation of a resist pattern, when selectively exposing the resist film obtained by applying the resist composition on a support, the exposed portion of the resist film changes from being poorly soluble to soluble in the alkali developer, while the unexposed portion of the resist film remains poorly soluble in alkali and does not change. Thus, a positive resist pattern is formed by alkali development.

[0024] On the other hand, when applying a solvent development process, the substrate component containing the (A1) component has high solubility in an organic developer before exposure. When acid is generated by exposure, the polarity increases due to the action of the acid, and the solubility in the organic developer decreases. Therefore, in the formation of a resist pattern, when selectively exposing the resist film obtained by applying the resist composition on a support, the exposed portion of the resist film changes from being soluble to poorly soluble in the organic developer, while the unexposed portion of the resist film remains soluble and does not change. Thus, by developing with an organic developer, contrast can be created between the exposed portion and the unexposed portion, and a negative resist pattern is formed.

[0025] In the resist composition of this embodiment, the (A) component may be used alone or in combination of two or more.

[0026] ·Regarding the (A1) component (A1) component is a resin component whose solubility in a developer changes by the action of an acid. (A1) component has a structural unit (a0) represented by the following general formula (a0-1). (A1) component may have other structural units as necessary in addition to the structural unit (a0).

[0027] ≪Structural unit (a0)≫ Structural unit (a0) is a structural unit represented by the following general formula (a0-1).

[0028] [Chemical formula] [In the formula, R 01 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Ya 01 is a single bond or a divalent linking group. Ar is a benzene ring or a naphthalene ring. m01 is an integer from 0 to 6. n01 is an integer from 1 to 4 as long as the valence allows.]

[0029] In the formula (a0-1), R 01 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 01 The alkyl group having 1 to 5 carbon atoms in 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. R 01 As, a hydrogen atom or a methyl group is particularly preferable from the viewpoint of industrial availability.

[0030] In the formula (a0-1), Ya 01 is a single bond or a divalent linking group. Ya 01 The divalent linking group in is not particularly limited, but examples of preferable ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, etc.

[0031] ·Divalent hydrocarbon group which may have a substituent: Ya 01 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0032] ··Ya 01 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.

[0033] ···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 preferable. Specifically, a methylene group [-CH 2 -], an ethylene group [-(CH 2 ) 2 -], a trimethylene group [-(CH 2 ) 3 -], a tetramethylene group [-(CH 2 ) 4 -], a pentamethylene group [-(CH 2 ) 5 -], etc. may 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 preferable. Specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups; -CH(CH3 )CH 2 -,-CH(CH 3 )CH(CH 3 )-,-C(CH 3 ) 2 CH 2 -,-CH(CH 2 CH 3 )CH 2 -,-C(CH 2 CH 3 ) 2 -CH 2 -and other alkylethylene groups such as -CH(CH 3 )CH 2 CH 2 -,-CH 2 CH(CH 3 )CH 2 -and other alkyltrimethylene groups such as -CH(CH 3 )CH 2 CH 2 CH 2 -,-CH 2 CH(CH 3 )CH 2 CH 2 -and other alkyltetramethylene groups such as alkylalkylene groups. Examples of the alkyl group in the alkylalkylene group include linear alkyl groups having 1 to 5 carbon atoms.

[0034] 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.

[0035] ···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 hetero atom 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 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 two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be mentioned.

[0036] 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 preferable, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. As the halogen atom as the substituent, a fluorine atom is 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. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O- is preferable.

[0037] ··Ya 01 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 hetero atoms. 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. 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.

[0038] 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, 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 of the cyclic aliphatic hydrocarbon group.

[0039] · Divalent linking group containing a heteroatom: Ya 01 When Ya is a divalent linking group containing a heteroatom, preferable examples of the linking group 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 or an acyl group), -S-, -S(=O)2 -1. -S(=O) 2 -O-, general formula -Y 21 -O-Y 22 -1. -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -1. -[Y 21 -C(=O)-O] m” -Y 22 -1. -Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O) 2 -O-Y 22 - groups represented by [wherein, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m” is an integer of 0 to 3.], etc. can be mentioned. 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 -1. -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -1. -[Y 21 -C(=O)-O] m” -Y 22 -1. -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. As the divalent hydrocarbon group, the same ones as those mentioned in the description of the divalent linking group in the above Ya 01 can be mentioned. 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 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. In the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 -, m” is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, in the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 -, the group represented by the formula -Y 21 -C(=O)-O-Y 22 - is particularly preferred. Among them, the group represented by the formula -(CH 2 ) a’ -C(=O)-O-(CH 2 ) b’ - is preferred. 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.

[0040] Among the above, Ya 01 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. Among these, Ya 01 is preferably a single bond.

[0041] In the formula (a0-1), Ar is a benzene ring or a naphthalene ring, and preferably a benzene ring. In the formula (a0-1), m01 is an integer of 0 to 6, preferably an integer of 0 to 4, and more preferably 1 or 2. In the formula (a0-1), when m01 is 0, the structure of the aliphatic ring in the condensed ring of the aliphatic ring and the aromatic ring is a 4-membered ring. In the formula (a0-1), n01 is an integer of 1 to 4 as long as the valence allows, preferably an integer of 1 to 3, more preferably 1 or 2, and particularly preferably 1.

[0042] Specific examples of the structural unit (a0) are shown below. In the following formulas, R 01 is the same as R in the formula (a0-1). 01

[0043]

Chemical formula

[0044]

Chemical formula

[0045] Among the above, as the structural unit (a0), at least one selected from the group consisting of the structural units represented by the formulas (a0-u-1), (a0-u-4), (a0-u-7) and (a0-u-11) is preferable.

[0046] The structural unit (a0) contained in the component (A1) may be one kind or two or more kinds. The proportion of the structural unit (a0) in the component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and still more preferably 40 to 60 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). ​By setting the proportion of the structural unit (a0) to be equal to or higher than the lower limit value of the above-mentioned preferred range, lithography characteristics such as sensitivity and roughness improvement are enhanced. On the other hand, when it is equal to or lower than the upper limit value of the above-mentioned preferred range, a balance with other structural units can be achieved, and various lithography characteristics become favorable.

[0047] ≪Other Structural Units≫ (Component (A1) may, in addition to the above-described structural unit (a0), optionally have other structural units. Examples of the other structural units include a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid (provided that those corresponding to the structural unit (a0) are excluded); a structural unit (a5) that generates an acid upon exposure; a structural unit (a2) containing a lactone-containing cyclic group, -SO 2 -containing cyclic group or a carbonate-containing cyclic group; a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group; a structural unit (a4) containing an acid-non-dissociable aliphatic cyclic group; a structural unit (a10) represented by the general formula (a10-1) described later; a structural unit derived from styrene; a structural unit derived from a styrene derivative, and the like.

[0048] ·Regarding the 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 (provided that those corresponding to the structural unit (a0) are excluded).

[0049] 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 (-SO 3 H), 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 the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0050] 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 such that after some 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 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 higher polarity than the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the whole component (A1) increases. By the increase in polarity, relatively, the solubility in the developer changes. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

[0051] Examples of the acid-dissociable group include those proposed as the acid-dissociable group of the base resin for the chemically amplified resist composition. Specific examples of those proposed as the acid-dissociable group of the base resin for the chemically amplified resist composition include the "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", and "tertiary alkyloxycarbonyl acid-dissociable group" described below.

[0052] Acetal-type acid-dissociable group: Examples of the acid-dissociable group that protects the carboxy group or the 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 the "acetal-type acid-dissociable group").

[0053] [Chemical formula] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. Ra' 3 is a hydrocarbon group, and Ra' 3 is, Ra' 1 , Ra' 2It may combine with any one of them to form a ring.

[0054] In formula (a1-r-1), Ra’ 1 and Ra’ 2 Among them, it is preferable that at least one is a hydrogen atom, and it is more preferable that both are hydrogen atoms. Ra’ 1 or Ra’ 2 When it is an alkyl group, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. 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, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0055] In formula (a1-r-1), Ra’ 3 As the hydrocarbon group, a linear or branched alkyl group, or a cyclic hydrocarbon group is mentioned. 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 preferable, and a methyl group or an ethyl group is more preferable.

[0056] 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 preferable.

[0057] 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, a monocycloalkane having 3 to 12 carbon atoms is preferable, a monocycloalkane having 3 to 8 carbon atoms is more preferable, and a monocycloalkane having 5 to 6 carbon atoms is still more preferable. Specific examples of the monocycloalkane include cyclopentane and cyclohexane. 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 specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0058] 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, 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; and aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring 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. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. 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 hydrogen atom 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.

[0059] Ra’ 3 The cyclic hydrocarbon group in [description] may have a substituent. Examples of this substituent include, for example, -R P1 、-R P2 -O-R P1 、-R P2 -CO-R P1 、-R P2 -CO-OR P1 、-R P2 -O-CO-R P1 、-R P2 -OH、-R P2 -CN or -R P2 -COOH (hereinafter, these substituents are also collectively referred to as "Ra 05 ").) etc. are mentioned. 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, R P1 and R P2Some or all of the hydrogen atoms of the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group 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 types of the above substituents. Examples of the monovalent chain-like 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, and the like. 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; polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0060] Ra’ 3 is Ra’ 1 or 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, and the like.

[0061] Tertiary 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-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for the sake of convenience.

[0062] [ka] [In the formula, Ra' 4 ~Ra' 6 are each a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0063] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 As the hydrocarbon group of Ra' 3 The same can be mentioned.

[0064] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably used. On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0065] [Chemical formula] [In formula (a1-r2-1), Ra’ 10 represents an alkyl group having 1 to 10 carbon atoms or a group represented by the following general formula (a1-r2-r1). Ra’ 11 is a group that forms an aliphatic cyclic group together with the carbon atom to which Ra’ 10 is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms of this cyclic hydrocarbon group may be substituted. Ra 01 ~Ra 03 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group and aliphatic cyclic saturated hydrocarbon group may be substituted. Ra 01 ~Ra 03 Two or more of them may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 04 is an aromatic hydrocarbon group that may have a substituent. 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 or a hydrogen atom. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 14 is a hydrocarbon group that may have a substituent. * indicates a bond.]

[0066] [Chemical formula] [In the formula, Ya 0 is a quaternary carbon atom. Ra 031 , Ra 032 and Ra 033 are each independently a hydrocarbon group that may have a substituent. However, Ra 031 , Ra 032 and Ra 033One or more of them are hydrocarbon groups having at least one polar group.

[0067] In the above formula (a1-r2-1), Ra’ 10 The alkyl group having 1 to 10 carbon atoms is preferably the group exemplified as the linear or branched alkyl group of Ra’ in the formula (a1-r-1). Ra’ 3 is preferably an alkyl group having 1 to 5 carbon atoms. 10

[0068] In the formula (a1-r2-r1), Ya 0 is a quaternary carbon atom. That is, Ya 0 (carbon atom) has 4 adjacent carbon atoms bonded thereto.

[0069] In the formula (a1-r2-r1), Ra 031 , Ra 032 and Ra 033 are each independently a hydrocarbon group which may have a substituent. Ra 031 , Ra 032 and Ra 033 Examples of the hydrocarbon group in include, each independently, a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group.

[0070] Ra 031 , Ra 032 and Ra 033 The linear alkyl group in is preferably having 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. can be mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable. Ra 031 , Ra 032 and Ra 033In the formula, the branched-chain alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc. can be mentioned, and isopropyl group is preferred. Ra 031 , Ra 032 and Ra 033 In the formula, the linear or cyclic alkenyl group is preferably an alkenyl group having 2 to 10 carbon atoms.

[0071] Ra 031 , Ra 032 and Ra 033 In the formula, the cyclic 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 monocycloalkane is preferred. As the monocycloalkane, monocycloalkane having 3 to 12 carbon atoms is preferred, monocycloalkane having 3 to 8 carbon atoms is more preferred, and monocycloalkane having 5 to 6 carbon atoms is still more preferred. Specifically, cyclopentane, cyclohexane, etc. can be mentioned as the monocycloalkane. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from polycycloalkane is preferred. As the polycycloalkane, those having 7 to 12 carbon atoms are preferred, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

[0072] Ra 031 , Ra 032 and Ra 033The aromatic hydrocarbon group in the above formula (1) is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted 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. Specific examples of the aromatic hydrocarbon group include a group in which one hydrogen atom is removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom is removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0073] The above Ra 031 , Ra 032 and Ra 033 When the hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include a hydroxy group, a carboxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), an alkyloxycarbonyl group, etc.

[0074] Among the above, Ra 031 , Ra 032 and Ra 033In the formula, the hydrocarbon group which may have a substituent is preferably a linear or branched alkyl group which may have a substituent, and more preferably a linear alkyl group.

[0075] However, Ra 031 Ra 032 and Ra 033 One or more of them are hydrocarbon groups having at least a polar group. The "hydrocarbon group having a polar group" includes both a group in which a methylene group (-CH 2 -) constituting the hydrocarbon group is substituted with a polar group, and a group in which at least one hydrogen atom constituting the hydrocarbon group is substituted with a polar group. As such a "hydrocarbon group having a polar group", a functional group represented by the following general formula (a1-p1) is preferable.

[0076]

Chemical formula

[0077] In the formula (a1-p1), Ra 07 represents a divalent hydrocarbon group having 1 to 12 carbon atoms. Ra 07 The number of carbon atoms of Ra is 1 to 12, preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and particularly preferably 1 to 2. Ra 07 The hydrocarbon group in Ra is preferably a chain or cyclic aliphatic hydrocarbon group, and more preferably a chain hydrocarbon group. Ra 07Examples include linear alkanediyl groups such as ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched-chain alkanediyl groups such as propane-1,2-diyl group, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; polycyclic divalent alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Among them, the alkanediyl group is preferred, and the linear alkanediyl group is more preferred.

[0078] In the formula (a1-p1), Ra 08 represents a divalent linking group containing a heteroatom. Ra 08 Examples include -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as an alkyl group, an acyl group, etc.), -S-, -S(=O) 2 -, -S(=O) 2 -O-, etc. Among these, -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O- are preferred, and -O-, -C(=O)- are particularly preferred.

[0079] In the formula (a1-p1), Ra 06 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Ra 06The carbon number is from 1 to 12, and from the viewpoint of solubility in the developer, the carbon number of 1 to 8 is preferable, the carbon number of 1 to 5 is more preferable, the carbon number of 1 to 3 is still more preferable, the carbon number of 1 or 2 is particularly preferable, and 1 is most preferable.

[0080] Ra 06 The hydrocarbon group in Ra may be a linear hydrocarbon group, a cyclic hydrocarbon group, or a hydrocarbon group combining a linear and a cyclic group. Examples of the linear hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, and the like.

[0081] The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1-(adamantan-1-yl)alkane-1-yl group, a norbornyl group, a methylnorbornyl group, and an isobornyl group. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.

[0082] Ra 06In terms of solubility in the developer, a chain hydrocarbon group is preferred, a chain alkyl group is more preferred, and a straight-chain alkyl group is even more preferred.

[0083] In the formula (a1-p1), n p0 is an integer from 1 to 6, preferably an integer from 1 to 3, more preferably 1 or 2, and even more preferably 1.

[0084] Specific examples of the hydrocarbon group having at least a polar group are shown below. In the following formula, * is a bond bonded to the quaternary carbon atom (Ya 0 ).

[0085]

Chemical formula

[0086] In the formula (a1-r2-r1), Ra 031 , Ra 032 and Ra 033 Among them, the number of hydrocarbon groups having at least a polar group is one or more, but it may be appropriately determined in consideration of the solubility in the developer during resist pattern formation. For example, Ra 031 , Ra 032 and Ra 033 Preferably, one or two of them are used, and particularly preferably one.

[0087] The hydrocarbon group having at least a polar group may have a substituent other than the polar group. Examples of this substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.) and a halogenated alkyl group having 1 to 5 carbon atoms.

[0088] In the formula (a1-r2-1), Ra’ 11 (an aliphatic cyclic group formed together with the carbon atom to which Ra’ 10 is bonded) is preferably a group exemplified as an aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra’ 3 in the formula (a1-r-1).

[0089] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is the Ra' in the above formula (a1-r-1) 3 A group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in 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 in the above Ra' 3 may have. In formula (a1-r2-2), Ra 01 ~Ra 03 Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra 01 ~Ra 03 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 in Ra 01 ~Ra 03 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; 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.

[0090] Among the above Ra 01 ~Ra 03 Examples of the substituent of the linear saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by 05 include the same groups as the above Ra

[0091] Ra 01 ~Ra 03 Examples of the group containing a carbon-carbon double bond formed by the combination of two or more of them to form a cyclic structure include, for example, cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, cyclohexylideneethenyl group, etc. Among these, from the viewpoint of the ease of synthesis of the monomer compound that induces the constitutional unit (a1), cyclopentenyl group, cyclohexenyl group, cyclopentylideneethenyl group are preferable.

[0092] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is the Ra' in formula (a1-r-1) 3 The group mentioned as the monocyclic group or polycyclic group of the aliphatic hydrocarbon group is preferable. In formula (a1-r2-3), Ra 04 Examples of the aromatic hydrocarbon group in include the group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 04 is preferably the group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably the group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably the group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably the group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably the group obtained by removing one or more hydrogen atoms from benzene.

[0093] Examples of the substituent that Ra in formula (a1-r2-3) may have include, for example, methyl group, ethyl group, propyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl group, etc. 04

[0094] In formula (a1-r2-4), Ra' 12 and Ra' 13is, independently of each other, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Ra’ 12 and Ra’ 13 As the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in, for example, the above Ra 01 ~Ra 03 the same ones as the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in can be mentioned. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 Among them, a hydrogen atom and an alkyl group having 1 to 5 carbon atoms are preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group and an ethyl group are further preferable, and a methyl group is particularly preferable. In the above Ra’ 12 and Ra’ 13 When the linear saturated hydrocarbon group represented by is substituted, examples of the substituent include the same groups as the above Ra 05 .

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

[0096] Ra’ 14 The linear alkyl group in 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. can be mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0097] Ra’ 14The branched-chain alkyl group in [[ID=]] is preferably an alkyl group having 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc. may be mentioned, and an isopropyl group is preferred.

[0098] Ra’ 14 When [[ID=]] 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 monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 12 carbon atoms is preferred, a monocycloalkane having 3 to 8 carbon atoms is more preferred, and a monocycloalkane having 5 to 6 carbon atoms is still more preferred. Specific examples of the monocycloalkane include cyclopentane and cyclohexane. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from polycycloalkane is preferred. As the polycycloalkane, those having 7 to 12 carbon atoms are preferred, and specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0099] Ra’ 14 Examples of the aromatic hydrocarbon group in [[ID=]] include the same as those of the aromatic hydrocarbon group in Ra 04 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 which Ra’ 04Examples thereof include the same substituents that may be present.

[0100] Ra' in formula (a1-r2-4) 14 When it 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. Ra' in formula (a1-r2-4) 14 When it 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: As the acid dissociable group for protecting the hydroxyl group among the polar groups, for example, 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) can be mentioned.

[0114]

Chemical formula

[0115] In formula (a1-r-3), Ra’ 7 ~Ra’ 9 are each preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Also, 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] 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 with a substituent containing the acid-decomposable group, and a structural unit in which at least a part of the hydrogen atoms in the -C(=O)-OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected with a substituent containing the acid-decomposable group, and the like.

[0117] 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 formula (a1-1) or (a1-2).

[0118] [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 which may have an ether bond. n a1 is an integer of 0 to 2. Ra 1 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa 1 is n a2 +1-valent hydrocarbon group, and n a2 is an integer of 1 to 3, and Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).]

[0119] In the formula (a1-1), 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. may be mentioned. The alkyl halide 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., and 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.

[0120] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0121] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and usually, it is preferably saturated. More specifically, 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.

[0122] 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 preferable. Specifically, a methylene group [-CH 2 - ], an ethylene group [-(CH 2 ) 2 - ], a trimethylene group [-(CH 2 ) 3 - ], a tetramethylene group [-(CH 2 ) 4 - ], a pentamethylene group [-(CH 2) 5 -] etc. can be mentioned. The branched-chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferable. Specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 - etc. alkylethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 - etc. alkyltrimethylene groups; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2Examples of the alkyl alkylene group such as an alkyltetramethylene group include an alkyl alkylene group. As the alkyl group in the alkyl alkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0123] Examples of the aliphatic hydrocarbon group containing a ring in the 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. 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. As the monocycloalkane, a monocycloalkane having 3 to 12 carbon atoms is preferable, a monocycloalkane having 3 to 8 carbon atoms is more preferable, and a monocycloalkane having 5 to 6 carbon atoms is even more preferable. Specific examples of the monocycloalkane include cyclopentane and cyclohexane. 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. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0124] 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 number does not include the carbon number 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 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, 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 of the hydrogen atoms 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 of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0125] In the formula (a1-1), Ra 1 is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0126] In the formula (a1-2), Wa 1 The n a2 The +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, and 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 the structure, or a group combining a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure. The n a2 The +1-valent is preferably divalent to tetravalent, and more preferably divalent or trivalent.

[0127] In the formula (a1-2), Ra 2is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0128] Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0129]

Chemical formula

[0130]

Chemical formula

[0131]

Chemical formula

[0132]

Chemical formula

[0133]

Chemical formula

[0134]

Chemical formula

[0135]

Chemical formula

[0136]

Chemical formula

[0137]

Chemical formula

[0138] [Chemical formula]

[0139] [Chemical formula]

[0140] Specific examples of the structural unit represented by the above formula (a1-2) are shown below.

[0141] [Chemical formula]

[0142] The structural unit (a1) contained in the component (A1) may be one kind or two or more kinds. As the structural unit (a1), the structural unit represented by the above formula (a1-1) is more preferable because the characteristics (sensitivity, shape, etc.) in lithography using electron beam or EUV can be more easily enhanced. Among these, as the structural unit (a1), those containing the structural unit represented by the following general formula (a1-1-1) are particularly preferable.

[0143] [Chemical formula] [In the formula, Ra 1 ” is an acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).]

[0144] In the above formula (a1-1-1), R, Va 1 and n a1 are the same as R, Va 1 and n a1 in the above formula (a1-1). The description of the acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) 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.

[0145] When the component (A1) has the structural unit (a1), the proportion of the structural unit (a1) in the component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and still more preferably 40 to 60 mol% with respect to the total (100 mol%) of all the structural units 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-mentioned preferable range, lithography characteristics such as sensitivity, resolution, and roughness improvement are improved. On the other hand, when it is equal to or lower than the upper limit value of the above-mentioned preferable range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0146] ·Regarding the structural unit (a5) The structural unit (a5) is a structural unit that generates an acid upon exposure. In the structural unit (a5), an acid is generated during exposure, and the solubility of the component (A1) in the developer changes due to the action of the acid (the acid generated from the structural unit (a5)).

[0147] Examples of the structural unit (a5) include a structural unit containing a group represented by the following general formula (a5-an1).

[0148]

Chemical formula

[0149] In the formula (a5-an1), W 0 in the hydrocarbon group having 1 to 30 carbon atoms which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and Ya in the formula (a0-1) 01Examples of the divalent linking group in [the compound] include those similar to the aliphatic hydrocarbon group and the aromatic hydrocarbon group described above. W 0 A preferred example of [W] is a group represented by -[C(R f1 )(R f2 )] p0 -. In this formula, R f1 and R f2 are each independently a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, at least one of R f1 , R f2 is a fluorine atom or a fluorinated alkyl group, and p0 is an integer from 1 to 8. W 0 When [W] is a group represented by -[C(R f1 )(R f2 )] p0 -, the group represented by the formula (a5 - an1) is represented by the following general formula (a5 - an1 - 1).

[0150]

Chemical formula

[0151] In the formula (a5 - an1 - 1), as the alkyl group of R f1 , R f2 , an alkyl group having 1 to 5 carbon atoms is preferred, 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. can be mentioned. R f1 , R f2 As the fluorinated alkyl group of f1 , R f2A group in which some or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is preferred. R f1 , R f2 is preferably a fluorine atom or a fluorinated alkyl group. In the formula (a5 - an1 - 1), p0 is an integer of 1 to 8, preferably an integer of 1 to 4, and more preferably 1 or 2.

[0152] W 0 Other preferred examples of W include an aliphatic cyclic group or an aromatic hydrocarbon group which may have a substituent. Among them, a group obtained by removing two or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, camphor, benzene, etc. (which may have a substituent) is preferred.

[0153] As the structural unit (a5), a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferred. Preferred specific examples of such a structural unit (a5) include a structural unit represented by the following general formula (a5 - 1).

[0154] [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. W 0 is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent. Q 21 is a single bond or a divalent linking group. p01 is 0 or 1. m is an integer of 1 or more, and M m+ is an m-valent organic cation.]

[0155] In the formula (a5-1), 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, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The alkyl halide 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 fluorine atom, chlorine atom, bromine atom, iodine atom and the like, and a fluorine atom is particularly preferred. 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.

[0156] In the formula (a5-1), W 0 is the same as W in the formula (a5-an1), and is preferably a group represented by the general formula (a5-an1-1). 0

[0157] In the formula (a5-1), Q 21 is a single bond or a divalent linking group. Q 21 Examples of the divalent linking group in Q include the same ones as the divalent linking group in Ya in the formula (a0-1). Among them, as Q 01 a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a divalent linking group containing a hetero atom is preferable; a combination of a linear or branched alkylene group and a divalent linking group containing a hetero atom, a combination of a cyclic aliphatic hydrocarbon group and a divalent linking group containing a hetero atom, and a combination of an aromatic hydrocarbon group and a divalent linking group containing a hetero atom are more preferable; 21 ​​A linear or branched alkylene group, a combination of a linear or branched alkylene group and an ester bond [-C(=O)-O-], or a combination of a divalent alicyclic hydrocarbon group and an ester bond [-C(=O)-O-] is particularly preferred; a linear or branched alkylene group, or a combination of a linear or branched alkylene group and an ester bond [-C(=O)-O-] is most preferred.

[0158] In the formula (a5-1), p01 is 0 or 1, and 1 is preferred.

[0159] In the formula (a5-1), m is an integer of 1 or more, and M m+ is an m-valent organic cation. M m+ The organic cation of M is not particularly limited, and for example, an organic cation known as a photodegradable base used in a quencher of a resist composition or a cation part of an onium-based acid generator of a resist composition can be used. As such an organic cation, those similar to the cations represented by the general formula (ca-1), general formula (ca-2) or (ca-3) described later are preferably exemplified.

[0160] Specific examples of the structural unit represented by the formula (a5-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0161]

Chemical formula

[0162] Furthermore, further specific examples of the structural unit represented by the formula (a5-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0163]

Chemical formula

[0164] When the component (A1) has the constitutional unit (a5), the proportion of the constitutional unit (a5) in the component (A1) is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, and still more preferably 5 to 15 mol% with respect to the total (100 mol%) of all the constitutional units constituting the component (A1). When the proportion of the constitutional unit (a5) is at least the lower limit value of the above-mentioned preferred range, the lithography characteristics such as sensitivity and resolution, and the improvement effect of the resist pattern shape can be sufficiently obtained. On the other hand, when it is at most the upper limit value of the above-mentioned preferred range, the balance with other constitutional units can be achieved, and various lithography characteristics become good. In addition, sufficient solubility in a resist solvent (component (S) described later) can be ensured.

[0165] ·Regarding the constitutional unit (a2) The constitutional unit (a2) is a constitutional unit containing a lactone-containing cyclic group, a -SO 2 -containing cyclic group or a carbonate-containing cyclic group (excluding those corresponding to the constitutional unit (a0) and the constitutional unit (a1) respectively). The lactone-containing cyclic group, -SO 2 -containing cyclic group or carbonate-containing cyclic group in the constitutional unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1) is used for forming a resist film. Further, by having the constitutional unit (a2), the lithography characteristics and the like become good due to 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.

[0166] The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, in the case of only the lactone ring, it is a monocyclic group, and when it further has other ring structures, it is called a polycyclic group regardless of its structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group in the structural 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.

[0167] [Chemical formula] [In the formula, Ra’ 21 is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group; R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO 2 -containing cyclic group; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom, n’ is an integer of 0 to 2, and m’ is 0 or 1.]

[0168] In the general formulas (a2-r-1) to (a2-r-7), the alkyl group in Ra’ 21 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 and the like 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 in Ra’ 21 is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group in the above Ra’ 21 is linked to an oxygen atom (-O-) can be mentioned. Ra’ 21 The halogen atom in Ra’ Ra’ 21As the alkyl halide group in, the above Ra’ 21 Examples of the group in which some or all of the hydrogen atoms of the alkyl group in are substituted with the halogen atoms include such groups. As the alkyl halide group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0169] Ra’ 21 In -COOR” and -OC(=O)R” in, each of R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO 2 -containing cyclic group. The alkyl group in R” may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R” is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. When R” is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. 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 a bicycloalkane, a tricycloalkane, or a tetracycloalkane can be exemplified. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be mentioned. 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. The carbonate-containing cyclic group in R” is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by the general formulas (ax3-r-1) to (ax3-r-3) respectively can be mentioned. In R”, -SO2 - As for the cyclic group, -SO described below 2 - is the same as the cyclic group containing, and specifically includes groups represented by general formulas (a5-r-1) to (a5-r-4). Ra’ 21 As the hydroxyalkyl group in, those having 1 to 6 carbon atoms are preferable, and specifically, at least one of the hydrogen atoms of the alkyl group in the above Ra’ 21 is a group substituted with a hydroxyl group.

[0170] 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 include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. 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, for example, O-CH 2 -, -CH 2 -O-CH 2 -S-CH 2 -, -CH 2 -S-CH 2 - etc. are included. 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.

[0171] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are given below.

[0172]

Chemical formula

[0173]

Chemical formula

[0174] 「-SO 2 - containing cyclic group」 means that -SO is in its ring skeleton 2-containing ring-containing cyclic group, specifically, -SO 2 - in which the sulfur atom (S) forms part of the ring skeleton of the cyclic group. In the ring skeleton, -SO 2 -containing ring is counted as the first ring. If there is only this ring, it is a monocyclic group. If it has other ring structures, regardless of the structure, it is called a polycyclic group. -SO 2 -containing cyclic group may be a monocyclic group or a polycyclic group. -SO 2 -containing cyclic group, in particular, a cyclic group containing -O-SO 2 - in its ring skeleton, that is, a cyclic group containing a sultone ring in which -O-S- in -O-SO 2 - forms part of the ring skeleton is preferred. -SO 2 -containing cyclic groups, more specifically, groups represented by the following general formulas (a5-r-1) to (a5-r-4) can be mentioned.

[0175]

Chemical formula

[0176] In the general formulas (a5-r-1) to (a5-r-2), A” is the same as A” in the general formulas (a2-r-2), (a2-r-3), (a2-r-5). Ra’ 51As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in the above are the same as those exemplified in the description of Ra’ in the general formulas (a2-r-1) to (a2-r-7). 21 Those similar to those exemplified in the description thereof can be mentioned. Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are shown below. In the formulas, “Ac” represents an acetyl group.

[0177] [Chemical formula]

[0178] [Chemical formula]

[0179] [Chemical formula]

[0180] The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in its ring skeleton. Counting the carbonate ring as the first ring, in the case of only the carbonate 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 carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. As the carbonate ring-containing cyclic group, any group can be used without particular limitation. Specifically, the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) can be mentioned.

[0181] [Chemical formula] [In the formula, Ra’ x31is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group; R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO 2 -containing cyclic group; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, p’ is an integer of 0 to 3, and q’ is 0 or 1.]

[0182] In the general formulas (ax3-r-2) to (ax3-r-3), A” is the same as A” in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra’ 31 As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in, they are the same as those exemplified in the description of Ra’ in the general formulas (a2-r-1) to (a2-r-7) respectively. 21 Those similar to those mentioned in the description can be mentioned. Specific examples of the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) are given below.

[0183]

Chemical formula

[0184] As the constitutional unit (a2), among others, a constitutional unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable. Such a constitutional unit (a2) is preferably a constitutional unit represented by the following general formula (a2-1).

[0185]

Chemical formula

[0186] 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.

[0187] In the formula (a2-1), Ya 21 The divalent linking group in 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. Ya 21 The description of the divalent linking group (a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom) in is the same as the description of the divalent linking group (a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom) in Ya 01 in the above-described formula (a0-1).

[0188] Among the above, Ya 21 is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0189] In the formula (a2-1), Ra 21 is a lactone-containing cyclic group, a -SO 2 -containing cyclic group or a carbonate-containing cyclic group. Ra 21 The lactone-containing cyclic group, -SO 2- The cyclic group and the carbonate-containing cyclic group each preferably include a group represented by each of the aforementioned general formulas (a2-r-1) to (a2-r-7), a group represented by each of the general formulas (a5-r-1) to (a5-r-4), and a group represented by each of the general formulas (ax3-r-1) to (ax3-r-3). Among them, a lactone-containing cyclic group or a -SO 2 - containing cyclic group is preferable, and a group represented by the general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1) is more preferable. Specifically, any group represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), (r-sl-1-18) is more preferable.

[0190] The structural unit (a2) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) in the component (A1) is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, and even more preferably 5 to 15 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). When the proportion of the structural unit (a2) is equal to or higher than the lower limit value of the aforementioned preferable range, the effect of having the structural unit (a2) can be sufficiently obtained by the aforementioned effect. On the other hand, when it is equal to or lower than the upper limit value of the aforementioned preferable range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0191] ·Regarding the structural unit (a3) The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (excluding those corresponding to the structural unit (a1) or the structural unit (a2)). By the component (A1) having the structural unit (a3), the hydrophilicity of the component (A) is enhanced, contributing to the improvement of resolution. In addition, the acid diffusion length can be appropriately adjusted.

[0192] Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, etc., and a hydroxyl group is particularly preferable. Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group), and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected and used from among those proposed in many cases in, for example, a resin for an ArF excimer laser resist composition.

[0193] When the cyclic group is a monocyclic group, the number of carbon atoms is more preferably 3 to 10. Among them, a structural unit derived from an acrylate ester containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group are substituted with fluorine atoms is more preferable. Examples of the monocyclic group include a group obtained by removing two or more hydrogen atoms from a monocycloalkane. Specifically, examples include a group obtained by removing two or more hydrogen atoms from a monocycloalkane such as cyclopentane, cyclohexane, or cyclooctane. Among these monocyclic groups, a group obtained by removing two or more hydrogen atoms from cyclopentane and a group obtained by removing two or more hydrogen atoms from cyclohexane are industrially preferable.

[0194] When the cyclic group is a polycyclic group, the polycyclic group preferably has 7 to 30 carbon atoms. Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of the hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specifically, groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, groups obtained by removing two or more hydrogen atoms from norbornane, and groups obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferable.

[0195] The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any one can be used. The structural unit (a3) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and a structural unit containing a polar group-containing aliphatic hydrocarbon group is preferable. When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit derived from hydroxyethyl acrylate is preferable as the structural unit (a3). In addition, as the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-3) are preferably mentioned; when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a monocyclic group, the structural unit represented by the formula (a3-4) is preferably mentioned.

[0196]

Chemical formula

[0197] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3-position and 5-position of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group. j is preferably 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0198] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or 6-position of the norbornyl group.

[0199] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. It is preferable that a 2-norbornyl group or 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0200] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0201] The structural unit (a3) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a3), the proportion of the structural unit (a3) in the component (A1) is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, and still more preferably 5 to 15 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). If the proportion of the structural unit (a3) is equal to or greater than the lower limit of the above-mentioned preferred range, the effect of having the structural unit (a3) can be sufficiently obtained by the above-described effect. On the other hand, if it is equal to or less than the upper limit of the above-mentioned preferred range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0202] ·Regarding the structural unit (a4) The structural unit (a4) is a structural unit containing an acid-non-dissociable aliphatic cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. In addition, the hydrophobicity of the component (A) increases. The increase in hydrophobicity contributes to the improvement of resolution, resist pattern shape, etc., particularly in the case of the solvent development process. The "acid-non-dissociable cyclic group" in the structural unit (a4) is a cyclic group that remains in the structural unit as it is without dissociating even when an acid acts when an acid is generated in the resist composition by exposure (for example, when an acid-generating structural unit is exposed or when an acid is generated from the component (B) described later).

[0203] As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid-non-dissociable aliphatic cyclic group is preferable. Many of the cyclic groups conventionally known for use in resin components of resist compositions such as for ArF excimer lasers and for KrF excimer lasers (preferably for ArF excimer lasers) can be used. From the viewpoint of easy availability in industry, etc., it is particularly preferably at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

[0204] Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7). In the following formulas, R αrepresents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0205] [Chemical formula]

[0206] The structural unit (a4) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a4), the proportion of the structural unit (a4) in the component (A1) is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, still more preferably 5 to 15 mol%, based on 100 mol% of the total of all the structural units constituting the component (A1). If the proportion of the structural unit (a4) is at least the lower limit of the above preferred range, the effects due to having the structural unit (a4) can be sufficiently obtained. On the other hand, if it is at most the upper limit of the above preferred range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0207] ·Regarding the structural unit (a10) The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0208] [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 x1 is an (n ax1 +1)-valent aromatic hydrocarbon group. n ax1 is an integer of 1 or more. ]

[0209] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. may be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms in R is a group in which part 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 fluorine atom, chlorine atom, bromine atom, iodine atom, etc., and 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, a methyl group or a trifluoromethyl group is more preferable, a hydrogen atom or a methyl group is still more preferable, and a methyl group is particularly preferable.

[0210] In the above formula (a10-1), Ya x1 is a single bond or a divalent linking group. Ya x1 Regarding the divalent linking group (a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom) in Ya, the description is the same as the description of the divalent linking group (a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom) in Ya in the above formula (a0-1). 01 is the same as the description of the divalent linking group (a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom) in Ya in the above formula (a0-1).

[0211] Among the above, Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-] is more preferable.

[0212] In the above formula (a10-1), Wa x1 is an (n ax1 +1)-valent aromatic hydrocarbon group. Wa x1 Regarding the aromatic hydrocarbon group in Wa, from the aromatic ring (nax1 Examples of the group excluding (+1) hydrogen atoms are given. Here, the aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and it 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. 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, and the like. Examples of the heteroatom 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. Also, Wa x1 Examples of the aromatic hydrocarbon group in include groups obtained by removing (n ax1 +1) hydrogen atoms from aromatic compounds containing two or more aromatic rings (such as biphenyl and fluorene). Among the above, 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 still more preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene.

[0213] 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, still more preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0214] 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.

[0215]

Chemical formula

[0216]

Chem.

[0217]

Chem.

[0218]

Chem.

[0219] (A1) component may have one or more structural units (a10). When the (A1) component has a structural unit (a10), the proportion of the structural unit (a10) in the (A1) component is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, and even more preferably 5 to 15 mol% with respect to the total (100 mol%) of all the structural units constituting the (A1) component. When the proportion of the structural unit (a10) is equal to or higher than the lower limit value of the above preferred range, the sensitivity is more likely to be enhanced in resist pattern formation. On the other hand, when it is equal to or lower than the upper limit value of the above preferred range, the balance with other structural units can be achieved, and various lithography characteristics become good.

[0220] · Regarding structural units derived from styrene and structural units derived from styrene derivatives (hereinafter these are collectively referred to as "structural units (st)") "Styrene" is a concept including styrene and those in which the hydrogen atom at the α-position of styrene is substituted with a substituent such as an alkyl group or a halogenated alkyl group. Examples of the alkyl group as the substituent here include alkyl groups having 1 to 5 carbon atoms, and examples of the halogenated alkyl group as the substituent include halogenated alkyl groups having 1 to 5 carbon atoms. Examples of "styrene derivatives" include those in which a substituent is bonded to the benzene ring of styrene in which the hydrogen atom at the α-position may be substituted with a substituent. Unless otherwise specified, the α-position (α-carbon atom) refers to the carbon atom to which the benzene ring is attached. The "structural unit derived from styrene" and the "structural unit derived from a styrene derivative" mean a structural unit formed by cleavage of the ethylenic double bond of styrene or a styrene derivative. The structural unit (st) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol%, more preferably 3 to 20 mol%, based on the total (100 mol%) of all the structural units constituting the component (A1).

[0221] The component (A1) contained in the resist composition may be used alone or in combination of two or more. In the resist composition of the present embodiment, examples of the component (A1) include a polymer compound having a repeating structure of the structural unit (a0). Preferred examples of the component (A1) include a polymer compound having a repeating structure of the structural unit (a0) and the structural unit (a1). Specifically, as the component (A1), a polymer compound composed of a repeating structure of the structural unit (a0) and the structural unit (a1), and a polymer compound composed of a repeating structure of the structural unit (a0), the structural unit (a1), and the structural unit (a5) can be preferably used.

[0222] Such a component (A1) can be produced by dissolving monomers that induce each structural unit in a polymerization solvent, adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (e.g., V-601, etc.) thereto, and performing polymerization. Alternatively, such a component (A1) can be produced by dissolving a monomer that induces the structural unit (a0) and, if necessary, a monomer that induces a structural unit other than the structural unit (a0) in a polymerization solvent, adding the above radical polymerization initiator thereto, performing polymerization, and then performing a deprotection reaction. In addition, during polymerization, for example, HS-CH2 -CH 2 -CH 2 -C(CF 3 ) 2 -OH such as a chain transfer agent may be used in combination, and -C(CF 3 ) 2 -OH groups may be introduced at the ends. 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 in reducing development defects and LER (Line Edge Roughness: non-uniform irregularities on the sidewalls of the line).

[0223] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1000 to 50000, more preferably 2000 to 30000, and even more preferably 3000 to 20000. When the Mw of the component (A1) is below the upper limit value of the above preferred range, there is sufficient solubility in a resist solvent for use as a resist. On the other hand, when it is above the lower limit value of the above preferred range, the dry etching resistance and the cross-sectional shape of the resist pattern are good. The dispersity (Mw / Mn) of the 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.

[0224] ·Regarding the base material components other than the component (A1) In the resist composition of the present embodiment, as the component (A), a base material component that does not correspond to the component (A1) and whose solubility in a developer changes by the action of an acid may be used in combination. The base material components that do not correspond to the component (A1) are not particularly limited, and can be arbitrarily selected from a number of those conventionally known as base material components for chemically amplified resist compositions, and one kind of a high molecular compound or a low molecular compound may be used alone, or two or more kinds may be used in combination.

[0225] In the resist composition of the present embodiment, the content of the component (A) may be adjusted according to the resist film thickness to be formed and the like.

[0226] <Base component: Component (D)> In the resist composition of the present embodiment, the component (D) contains a photo-dissociable base (D0) (hereinafter also referred to as the “component (D0)”) that controls the diffusion of the acid generated by exposure. By using the component (D0), in resist pattern formation, the sensitivity is increased, and a resist pattern with lower roughness is more likely to be formed. As the component (D), at least the component (D0) is used, and other base components that control the diffusion of the acid may be used in combination with the component (D0).

[0227] ·Regarding the component (D0) The component (D0) is a photo-dissociable base that controls the diffusion of the acid generated by exposure. The component (D0) is a compound having an anion part and a cation part, and the cation part decomposes by exposure, losing the acid diffusion control property. That is, the component (D0) does not act as a quencher because it decomposes in the exposed part of the resist film and loses the acid diffusion control property (basicity), and acts as a quencher in the unexposed part of the resist film. In the component (D0), the energy of the LUMO (Lowest Unoccupied Molecular Orbital) of the cation part is -4.70 eV or less.

[0228] In this specification and the claims of the present patent, the energy of the LUMO of the cation part in a compound having an anion part and a cation part indicates the simulation value by CAChe. For example, it is measured by performing structure optimization using MM geometry (MM2) or PM3 geometry with CAChe Work System Pro Version 6.1.12.33.

[0229] ··Cation part in the component (D0) The energy of the LUMO of the cationic part in the (D0) component is -4.70 eV or less, preferably -4.90 eV or less, more preferably -5.20 eV or less. On the other hand, the lower limit is preferably -6.00 eV or more, more preferably -5.80 eV or more, and even more preferably -5.60 eV or more. If the energy of the LUMO of the cationic part is equal to or less than the upper limit value of the above range, the sensitivity can be enhanced, and a resist pattern with reduced roughness can be easily formed. On the other hand, if the energy of the LUMO of the cationic part is equal to or more than the lower limit value of the preferred range, the change over time of the (D0) component in the resist composition is suppressed.

[0230] The energy of the LUMO of the cationic part in the (D0) component can be controlled, for example, by selecting the skeleton of the cation structure and the type of substituents (such as fluorine atom, sulfonyl group, sulfonylcyclohexyl group, etc.). Preferred cationic parts in the (D0) component include, for example, organic cations represented by the following general formula (ca-1) or (ca-3).

[0231] [Chemical formula] [In the formula, R 201 ~R 203 , R 206 and R 207 each independently represent 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 represent 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 -SO 2- It contains a cyclic group. L 201 represents -C(=O)- or -C(=O)-O-.]

[0232] In the above general formulas (ca-1) and (ca-3), R 201 ~R 203 、R 206 and R 207 Examples of the aryl group in include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. R 201 ~R 203 、R 206 and R 207 Examples of the alkyl group in include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. R 201 ~R 203 、R 206 and R 207 Examples of the alkenyl group in preferably have 2 to 10 carbon atoms. R 201 ~R 203 、R 206 and R 207 Examples of the substituent that R

[0233]

Chemical formula

[0234] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0235] R’ 201 The aromatic hydrocarbon group in 201 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’ 201 Specific examples of the aromatic ring of the aromatic hydrocarbon group in 201 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’ 201 Specific examples of the aromatic hydrocarbon group in 201 include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., such as arylalkyl groups). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0236] R’ 201 The cyclic aliphatic hydrocarbon group in 201 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 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 a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane, etc. are mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, as the polycycloalkane, a polycycloalkane having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane; a polycycloalkane having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton is more preferable.

[0237] Among them, R’ 201 The cyclic aliphatic hydrocarbon group in is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0238] The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further 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. Specifically, a methylene group [-CH 2 -], an ethylene group [-(CH 2 )2 -), trimethylene group [-(CH 2 ) 3 -), tetramethylene group [-(CH 2 ) 4 -), pentamethylene group [-(CH 2 ) 5 -), etc. can be mentioned. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. of alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 -, etc. of alkylethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc. of alkyltrimethylene groups; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2Examples of the alkylalkylene group include an alkyltetramethylene group such as -etc. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0239] Also, R' 201 The cyclic hydrocarbon group in may contain a hetero atom such as a heterocycle. Specifically, the lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7), the -SO 2 -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). * in the following chemical formulas represents a bond.

[0240]

Chemical formula

[0241] R' 201 Examples of the substituent in the cyclic group of 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, etc. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group, and most preferably a methoxy group, an ethoxy group. The halogen atom as a substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as a substituent include a group in which some or all of the 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. The carbonyl group as a substituent is a methylene group (-CH that constitutes a cyclic hydrocarbon group2 is a group for substitution.

[0242] A chain alkyl group which may have a substituent: R’ 201 The chain alkyl group of 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 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.

[0243] A chain alkenyl group which may have a substituent: R’ 201 The chain alkenyl group of may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, further 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), butynyl group, etc. Examples of the branched 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, more preferably vinyl group and propenyl group, and particularly preferably vinyl group.

[0244] R’ 201 Examples of the substituent in the chain alkyl group or alkenyl group of include, for example, alkoxy group, halogen atom, alkyl halide group, hydroxyl group, carbonyl group, nitro group, amino group, the above R’ 201Examples of the cyclic group and the like include those in

[0245] R’ 201 The cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent, in addition to those described above, as the cyclic group which may have a substituent or the chain alkyl group which may have a substituent, those similar to the acid dissociable group represented by the above formula (a1-r-2) are also included.

[0246] 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 -SO 2 -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4) respectively, etc. are preferable.

[0247] In the above general formulas (ca-1) and (ca-3), when R 201 ~R 203 、R 206 ~R 207 are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatoms such as sulfur atom, oxygen atom, nitrogen atom, carbonyl group, -SO-, -SO 2 -、-SO 3 -、-COO-、-CONH- or -N(R N )-(the R Nis an alkyl group having 1 to 5 carbon atoms. It may be bonded via a functional group such as). As the ring formed, one ring containing the sulfur atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring including the sulfur atom, and particularly preferably a 5- to 7-membered ring. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring and the like.

[0248] 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.

[0249] 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 -SO 2 -containing cyclic group which may have a substituent. R 210 Examples of the aryl group in include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable. R 210 Examples of the alkyl group in include a linear or cyclic alkyl group having preferably 1 to 30 carbon atoms. R 210 Examples of the alkenyl group in preferably have 2 to 10 carbon atoms. R 210 In, the -SO 2 -containing cyclic group which may have a substituent is preferably a "-SO 2 -containing polycyclic group", and more preferably a group represented by the above general formula (a5-r-1).

[0250] Specific examples of the preferred cation represented by the formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-61). For each of the exemplified cations, the energy value (eV) of the LUMO is also shown.

[0251] [Chemical formula]

[0252] [Chemical formula]

[0253] [Chemical formula]

[0254] [Chemical formula]

[0255] [Chemical formula] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituents are the same as those exemplified as the substituents that R 201 ~R 207 may have.]

[0256] [Chemical formula]

[0257] [Chemical formula]

[0258] [Chemical formula]

[0259] Specific examples of the preferred cations represented by the formula (ca-3) include cations represented by the following chemical formulas (ca-3-1) to (ca-3-6). For each of the exemplified cations, the energy value (eV) of the LUMO is also indicated.

[0260] [Chemical formula]

[0261] In the resist composition of the present embodiment, among the above, the cation moiety in the compound (D0) is preferably an organic cation represented by the general formula (ca-1) or an organic cation represented by the general formula (ca-3). Specifically, a cation represented by any of the above chemical formulas (ca-1-22), (ca-1-24), (ca-1-28), (ca-1-53), (ca-1-55), (ca-1-58), (ca-1-59), (ca-1-60), (ca-1-61) or (ca-3-1) is preferred, and a cation represented by any of the above chemical formulas (ca-1-24), (ca-1-28), (ca-1-53), (ca-1-55), (ca-1-58), (ca-1-61) or (ca-3-1) is more preferred.

[0262] ··Anion moiety in the component (D0) The anion moiety in the component (D0) is not particularly limited as long as it can control the diffusion of the acid generated by exposure from components other than the component (D0). For example, one or more anions selected from the group consisting of an anion represented by the following general formula (d0-an1), an anion represented by the following general formula (d0-an2), and an anion represented by the following general formula (d0-an3) are preferably mentioned.

[0263] [Chemical formula] [In the formula, Rd 1 ~Rd 4is, independently of one another, an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group. However, Rd in formula (d0-an2) 2 in is such that no fluorine atom is bonded to the carbon atom adjacent to the S atom. Yd 1 is a single bond or a divalent linking group.]

[0264] ··· the anion represented by general formula (d0-an1) In the above formula (d0-an1), 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, as Rd 1 , an optionally substituted aromatic hydrocarbon group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkyl group is preferable. Examples of the substituents that 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 the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is included as a substituent, it may be via an alkylene group, and in this case, the linking groups represented by the above formulas (y-al-1) to (y-al-5) are preferable as the substituents. Preferable examples of the aromatic hydrocarbon group 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). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The linear alkyl group preferably has 1 to 10 carbon atoms. 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.

[0265] 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, nitrogen atom, etc. Rd 1 is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms, and particularly preferably a fluorinated alkyl group (linear perfluoroalkyl group) in which all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms.

[0266] Preferred specific examples of the anion represented by the general formula (d0-an1) are shown below.

[0267]

Chemical formula

[0268] ··· An anion represented by the general formula (d0-an2) In the formula (d0-an2), 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 examples thereof are the same as those of the above R'. 201 ​However, Rd 2 In 2 , it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom (not fluorine-substituted). As a result, the anion represented by the general formula (d0-an2) becomes a moderately weak acid anion, and the quenching ability as the (D0) component is improved. Rd 2 Preferably, Rd is a linear alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. As the linear alkyl group, it is preferably having 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); a group obtained by removing one or more hydrogen atoms from camphor or the like is more preferable. Rd 2 The hydrocarbon group of Rd may have a substituent, and examples of the substituent include the same substituents as those which the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, linear alkyl group) in Rd in the formula (d0-an1) may have. 1

[0269] Hereinafter, preferable specific examples of the anion represented by the general formula (d0-an2) are shown.

[0270]

Chemical formula

[0271] ··· Anion represented by the general formula (d0-an3) In the formula (d0-an3), 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, and examples thereof include the same as those of R' 201 , 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 more preferably the same as the fluorinated alkyl group of Rd 1 .

[0272] In the formula (d0-an3), 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, and the R' 201 is the same as those described above. Among them, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent is preferable. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like. The hydrogen atom of the alkyl group of Rd 4 may be partially substituted with a hydroxyl group, a cyano group, or the like. Rd 4 The alkoxy group in Rd is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, 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 preferable.

[0273] Rd 4 The alkenyl group in Rd is the same as those of the alkenyl group in the above R' 201 and examples include a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0274] Rd 4 The cyclic group in Rd is the same as those of the cyclic group in the above R' 201 and examples include an alicyclic group obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, or an aromatic group such as a phenyl group and a naphthyl group. Rd 4When it is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in good lithography characteristics. Also, Rd 4 When it 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 good sensitivity and lithography characteristics.

[0275] In the formula (d0 - an3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in Yd is not particularly limited, and examples include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a heteroatom, and the like. These are the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom mentioned in the description of the divalent linking group in Ya in the above formula (a0 - 1). 01 Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0276] Preferred specific examples of the anion represented by the general formula (d0 - an3) are shown below.

[0277]

Chemical formula

[0278]

Chemical formula

[0279] In the resist composition of the present embodiment, among the above, the anion part in the compound (D0) is preferably an anion represented by the general formula (d0-an1) or an anion represented by the general formula (d0-an2), and more preferably an anion represented by the general formula (d0-an1).

[0280] Specific preferred examples of the photo-dissociable base (D0) are shown below. For each compound of the specific examples, the energy value (eV) of the LUMO of the cation part is also shown.

[0281] [Chemical formula]

[0282] [Chemical formula]

[0283] In the resist composition of the present embodiment, the component (D0) may be used alone or in combination of two or more. In the resist composition of the present embodiment, the content of the component (D0) is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 3 to 10 parts by mass with respect to 100 parts by mass of the component (A). When the content of the component (D0) is equal to or higher than the lower limit value of the above preferred range, lithography characteristics such as roughness reduction are particularly likely to be improved. On the other hand, when it is equal to or lower than the upper limit value of the above preferred range, the sensitivity is further increased and the throughput is also excellent.

[0284] ·Regarding the component (D1) The resist composition of the present embodiment may further contain a base component ((D) component) that controls the diffusion of the acid generated by exposure in addition to the above component (D0). Examples of such (D) component include a photo-dissociable base (D1) that does not correspond to the above component (D0) (hereinafter referred to as "(D1) component").

[0285] (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 preferable. 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, while in the unexposed portion of the resist film, they act as quenchers.

[0286]

Chemical formula

[0287] The description of the anion part of the (d1-1) component is the same as the description of the anion represented by the above general formula (d0-an1). The description of the anion part of the (d1-2) component is the same as the description of the anion represented by the above general formula (d0-an2). The description of the anion part of the (d1-3) component is the same as the description of the anion represented by the above general formula (d0-an3).

[0288] In the above general formulas (d1-1) to (d1-3), M m+ is an m-valent organic cation. M m+As the organic cation, those similar to the cations represented by the above general formula (ca-1) and general formula (ca-3) are preferably cited. Also, M m+ As the organic cation, the cations represented by the following general formula (ca-2), general formula (ca-4), and general formula (ca-5) are also preferably cited.

[0289] [Chemical formula] [In the formula, R 204 , R 205 and R 211 ~R 212 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 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group. x is 1 or 2. W 201 represents a (x + 1)-valent linking group. ]

[0290] In the above general formula (ca-2), (ca-4), and (ca-5), as the aryl group in R 204 , R 205 and R 211 ~R 212 , an unsubstituted aryl group having 6 to 20 carbon atoms is cited, and a phenyl group and a naphthyl group are preferable. R 204 , R 205 and R 211 ~R 212 As the alkyl group in, a linear or cyclic alkyl group having 1 to 30 carbon atoms is preferable. R 204 , R 205 and R 211 ~R 212 As the alkenyl group in, it is preferable that the number of carbon atoms is 2 to 10. R 204 , R 205 and R211 ~R 212 Examples of the substituent that ~R may have 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 the groups represented by the above general formulas (ca-r-1) to (ca-r-7).

[0291] In the above general formulas (ca-4) to (ca-5), R 211 ~R 212 When they are mutually bonded 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, or a nitrogen atom, or a functional group such as a carbonyl group, -SO-, -SO 2 -, -SO 3 -, -COO-, -CONH- or -N(R N )(wherein R N is an alkyl group having 1 to 5 carbon atoms). The formed ring preferably has one ring containing the sulfur atom in its ring skeleton, and is preferably a 3- to 10-membered ring, 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 thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, etc.

[0292] Y 201 each independently represents an arylene group, an alkylene group or an alkenylene group. Y 201 The arylene group in Y 01 is a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in Ya in the above formula (a0-1). Y 201 The alkylene group and alkenylene group in Y 201 are groups obtained by removing one hydrogen atom from the groups exemplified as the linear alkyl group and linear alkenyl group in the above R'.

[0293] In the formula (ca-4), x is 1 or 2. W 201 is a (x + 1)-valent, i.e., divalent or trivalent linking group. W 201 As the divalent linking group in W, a divalent hydrocarbon group which may have a substituent is preferable, and a divalent hydrocarbon group which may have a substituent similar to Ya in the above formula (a0-1) 01 can be exemplified. W 201 The divalent linking group in W may be linear, branched or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable. W 201 As the trivalent linking group in W, a group obtained by removing one hydrogen atom from the divalent linking group in the above W 201 and a group in which the divalent linking group is further bonded to the divalent linking group can be exemplified. W 201 As the trivalent linking group in W, a group in which two carbonyl groups are bonded to an arylene group is preferable.

[0294] Specific examples of the preferable cation represented by the general formula (ca-2) include a diphenyliodonium cation and a bis(4-tert-butylphenyl)iodonium cation.

[0295] Specific examples of the preferable cation represented by the general formula (ca-4) include cations respectively represented by the following chemical formulas (ca-4-1) to (ca-4-2).

[0296]

Chemical formula

[0297] Specific examples of the preferable cation represented by the general formula (ca-5) include cations respectively represented by the following general formulas (ca-5-1) to (ca-5-3).

[0298] [Chemical formula]

[0299] M m+ As the organic cation of M, the cations represented by the general formulas (ca-1) to (ca-5) are preferably exemplified, and the cation represented by the general formula (ca-1) is more preferable. The component (d1-1) may be used alone or in combination of two or more. The component (d1-2) may be used alone or in combination of two or more. The component (d1-3) may be used alone or in combination of two or more.

[0300] The component (D1) may be used alone or in combination of two or more. When the resist composition contains the component (D1), in the resist composition, the content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass with respect to 100 parts by mass of the component (A). When the content of the component (D1) is equal to or higher than the lower limit value of the above preferable range, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is equal to or lower than the upper limit value of the above preferable range, the sensitivity can be maintained well and the throughput is also excellent.

[0301] ·Regarding the component (D2) Further, as the component (D), it may contain a nitrogen-containing organic compound component that does not correspond to any of the above (D0) component and (D1) component (hereinafter referred to as the "component (D2)"). The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not correspond to any of the (D0) component and (D1) component, and may be arbitrarily used from known ones. Among them, aliphatic amines are preferable, and among them, secondary aliphatic amines and tertiary aliphatic amines are more preferable. 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) or cyclic amines in which at least one hydrogen atom of ammonia NH 3 is substituted with an alkyl group or a hydroxyalkyl group having 12 or fewer carbon atoms. 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 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

[0302] Examples of cyclic amines include 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 and piperazine. As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable, 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.

[0303] 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.

[0304] 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, etc.

[0305] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), in the resist composition, the content of the component (D2) is usually used 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 stability over time, etc. are improved.

[0306] <Other Components> The resist composition of this embodiment may further contain other components in addition to the above-described components (A) and (D). Examples of other components include the following components (B), (E), (F), (S), etc.

[0307] ≪Acid Generator Component (B)≫ The resist composition of this embodiment may further contain an acid generator component (B) (hereinafter referred to as "(B) component") that generates an acid upon exposure, in addition to the components (A) and (D). (B) component 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; and various types such as nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. Among these, as the (B) component, it is preferable to use an onium salt-based acid generator.

[0308] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as the "(b-1) component"), a compound represented by the general formula (b-2) (hereinafter also referred to as the "(b-2) component"), or a compound represented by the general formula (b-3) (hereinafter also referred to as the "(b-3) component").

[0309] [Chemical formula] [In the formula, R 101 and R 104 ~R 108 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. R 104 and R 105 may be bonded to each other to form a ring structure. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103 are each independently a single bond, an alkylene group or a fluorinated alkylene group. L 101 ~L 102 are each independently a single bond or an oxygen atom. L 103 ~L 105 are each independently a single bond, -CO- or -SO 2- is. m is an integer of 1 or more, and M’ m+ is an m-valent onium cation.]

[0310] {Anion part} · The anion in the (b-1) component In formula (b-1), R 101 is an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group.

[0311] Optionally substituted cyclic group: 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.

[0312] R 101 The aromatic hydrocarbon group in 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 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 101Specific examples of the aromatic hydrocarbon group in [description] 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 of the hydrogen atoms 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.

[0313] R 101 The cyclic aliphatic hydrocarbon group in [description] 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 a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane, cyclohexane, etc. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, 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, tricyclodecane, tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0314] Among them, R 101As the cyclic aliphatic hydrocarbon group in [reference], a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from polycycloalkane is more preferable.

[0315] 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. Specifically, methylene group [-CH 2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] and the like can be mentioned. The branched-chain aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferable. Specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 - and the like.2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 - and other alkylethylene groups such as -CH(CH 3 )CH 2 CH 2 - and -CH 2 CH(CH 3 )CH 2 - and other alkyltrimethylene groups such as -CH(CH 3 )CH 2 CH 2 CH 2 - and -CH 2 CH(CH 3 )CH 2 CH 2 - and other alkyltetramethylene groups and other alkylalkylene groups may be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0316] Also, the cyclic hydrocarbon group in R 101 may contain a hetero atom such as a heterocyclic ring. Specifically, the lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7), the -SO 2 -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16) may be mentioned. * in the following chemical formulas represents a bond that binds to Y 101 in the formula (b-1).

[0317]

Chemical formula

[0318] 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 a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, 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, and a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. Examples of the halogenated alkyl group as a substituent include a group in which part or all of the 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, and a tert-butyl group, are substituted with the above halogen atoms. The carbonyl group as a substituent is a group that replaces the methylene group (-CH 2 -) constituting the cyclic hydrocarbon group.

[0319] R 101 The cyclic hydrocarbon group in may be a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the condensed ring include those in which one or more aromatic rings are condensed to a polycycloalkane having a bridged ring system polycyclic skeleton. 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 ring type, a group containing a condensed ring in which two or three aromatic rings are condensed to a bicycloalkane is preferable, and a group containing a condensed ring in which two or three aromatic rings are condensed to bicyclo[2.2.2]octane is more preferable. Specific examples of the condensed cyclic group in R 101 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

[0320]

Chemical formula

[0321] R 101 Examples of the substituent that the condensed cyclic group in R may optionally have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and the like. 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 the above R 101 and are as described above. 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 or cyclohexane; a group obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO 2 -containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively; and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16), respectively.

[0322] Optionally substituted chain alkyl group: R 101 The chain 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, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, and the like.

[0323] The chain alkenyl group which may have a substituent: R 101 The chain alkenyl group of R may be linear or branched, preferably has 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), butynyl group, and the like. Examples of the branched-chain alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group, and the like. 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.

[0324] 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, and the cyclic group in the above R 101 and the like.

[0325] Among the above, R 101 preferably has a cyclic group which may have a substituent, and more preferably is a cyclic hydrocarbon group which may have a substituent. More specifically, a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) respectively; -SO represented by the general formulas (a5-r-1) to (a5-r-4) respectively 2- A cyclic group or the like is preferred.

[0326] 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 atoms other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like. Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon-based 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 the non-hydrocarbon-based oxygen atom-containing linking group and an alkylene group, and the like. A sulfonyl group (-SO 2 -) may be further linked to this combination. Examples of such a divalent linking group containing an oxygen atom include linking groups respectively represented by the following general formulas (y-al-1) to (y-al-7).

[0327]

Chemical formula

[0328] V’ 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0329] V’ 101 and V’ 102As the alkylene group in [description], it may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred. V’ 101 and V’ 102 As the alkylene group in [description], specifically, a methylene group [-CH 2 -]; -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups; an ethylene group [-CH 2 CH 2 -]; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 - and other alkylethylene groups; a trimethylene group (n-propylene group) [-CH 2 CH 2 CH 2 -]; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 - and other alkyltrimethylene groups; a tetramethylene group [-CH 2 CH 2 CH 2 CH 2 -]; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH3 ) CH 2 CH 2 - alkyltetramethylene groups such as; pentamethylene group [-CH 2 CH 2 CH 2 CH 2 CH 2 -] and the like. Also, in V’ 101 or V’ 102 some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra’ in the formula (a1-r-1) 3 A divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0330] Y 101 is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and the linking groups represented by the above formulas (y-al-1) to (y-al-5) are more preferred.

[0331] In formula (b-1), V 101 is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V 101 preferably have 1 to 4 carbon atoms. As the fluorinated alkylene group in V 101 a group in which some or all of the hydrogen atoms of the alkylene group in V 101 are substituted with fluorine atoms is mentioned. Among them, V 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0332] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0333] Specific examples of the anion part represented by the formula (b-1) include, for example, Y 101 When is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion can be mentioned; Y 101 When 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.

[0334] [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), or a chain alkyl group which may have a substituent. R” 102 is an aliphatic cyclic group which may have a substituent, a condensed cyclic group represented by the formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or a -SO 2 -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4). R” 103 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. V” 101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. v” are each independently an integer of 0 to 3, q” are each independently an integer of 0 to 20, and n” is 0 or 1.]

[0335] R” 101 、R” 102 and R” 103 The aliphatic cyclic group which may have a substituent of is the R in the formula (b-1) 101It is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in. As the substituent, R in the formula (b-1) 101 Examples thereof include the same groups as those that may substitute the cyclic aliphatic hydrocarbon group in.

[0336] R” 103 The aromatic cyclic group which may have a substituent in is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R in the formula (b-1). As the substituent, R in the formula (b-1) 101 Examples thereof include the same groups as those that may substitute the aromatic hydrocarbon group in the cyclic hydrocarbon group in. 101

[0337] R” 101 The linear alkyl group which may have a substituent in is preferably a group exemplified as the linear alkyl group in R in the formula (b-1). 101

[0338] R” 103 The linear alkenyl group which may have a substituent in is preferably a group exemplified as the linear alkenyl group in R in the formula (b-1). 101 ·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 linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and examples thereof include the same groups as R in the formula (b-1). 101 104 , R 105 , R 104 R 104 , R 105 are preferably linear alkyl groups which may have a substituent, more preferably linear or branched alkyl groups, or linear or branched fluorinated alkyl groups. The number of carbon atoms of the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and still more preferably 1 to 3 carbon atoms. R 104 , R 105 For the chain-like alkyl group of, within the above range of the number of carbon atoms, the smaller it is, the more preferable it is because of reasons such as good solubility in the resist solvent. Also, in R 104 , R 105 In the chain-like alkyl group of, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and also, since the transparency to high-energy light or electron beams of 250 nm or less is improved, it is preferable. The ratio of fluorine atoms in the chain-like alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably, it is a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each is the same as V 101 in formula (b-1). In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0339] ·Anion in component (b-3) In formula (b-3), R 106 ~R 108 are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and each is the same as R 101 in formula (b-1). In formula (b-3), L 103 ~L 105 are each independently a single bond, -CO- or -SO 2 -.

[0340] Among these, as the anionic part of the component (B), the anion in the component (b-1) is preferable. Among these, an anion represented by any of the above general formulas (an-1) to (an-3) is more preferable, an anion represented by either of the general formulas (an-1) or (an-2) is still more preferable, and an anion represented by the general formula (an-2) is particularly preferable.

[0341] {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.

[0342] Preferred cation part ((M’ m+ )) 1 / m includes organic cations respectively represented by the above general formulas (ca-1) to (ca-5), and a cation represented by the general formula (ca-1) is preferable. Alternatively, also in the component (B), since the decomposition efficiency by exposure is likely to be increased, it is also preferable to have a cation part with a low LUMO energy, preferably a cation part with an energy of -6.00 eV or more and -4.70 eV or less.

[0343] In the resist composition of the present 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 40 parts by mass, and still more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the component (A). When the content of the component (B) is equal to or higher than the lower limit value of the above preferable range, in resist pattern formation, lithography characteristics such as sensitivity, reduction of LWR (line width roughness), and shape are further improved. On the other hand, when it is equal to or lower than the upper limit value of the above preferable range, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, and the storage stability as a resist composition is further enhanced.

[0344] ≪At least one compound (E) selected from the group consisting of organic carboxylic acids, oxo acids of phosphorus and their derivatives≫ In the resist composition of this embodiment, for the purpose of preventing sensitivity deterioration and improving resist pattern shape, stability over time during standing, etc., as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, oxo acids of phosphorus and their derivatives (hereinafter referred to as "(E) component") 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., which are suitable. Examples of the oxo acid of phosphorus include phosphoric acid, phosphonic acid, phosphinic acid, etc., and among these, phosphonic acid is particularly preferred. Examples of the derivatives of the oxo acid of phosphorus include esters in which the hydrogen atom of the above oxo acid is substituted with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, etc. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, etc. Examples of the derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid. In the resist composition of this embodiment, the (E) component may be used alone or in combination of two or more. When the resist composition contains the (E) component, the content of the (E) component is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the (A) component.

[0345] ≪Fluorine additive component (F)≫ The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "(F) component") in order to impart water repellency to the resist film or to improve lithography characteristics. As the (F) component, for example, the fluorine-containing polymer compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. More specifically, as the (F) component, polymers having a structural unit (f1) represented by the following general formula (f1-1) can be mentioned. As this polymer, a polymer (homopolymer) consisting 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); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) is preferred. 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 preferred.

[0346] [Chemical formula] [In the formula, R is the same as described above, Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 may be the same or different. nf 1 is an integer of 0 to 5, and Rf 101 is an organic group containing a fluorine atom.]

[0347] In the formula (f1-1), R bonded to the carbon atom at the α-position is the same as described above. As R, a hydrogen atom or a methyl group is preferred. In the formula (f1-1), Rf 102 and Rf 103Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferred. Rf 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms for Rf and Rf include the same ones as the alkyl group having 1 to 5 carbon atoms for R above, and a methyl group or an ethyl group is preferred. Rf 102 and Rf 103 Examples of the halogenated alkyl group having 1 to 5 carbon atoms for Rf and Rf specifically include a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferred. 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, and a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is preferred. 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.

[0348] 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. Also, in the hydrocarbon group containing a fluorine atom, preferably 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, a trifluoromethyl group, -CH 2 -CF 3 -CH 2 -CF 2 -CF 3, -CH(CF 3 ) 2 , -CH 2 -CH 2 -CF 3 , -CH 2 -CH 2 -CF 2 -CF 2 -CF 2 -CF 3 is particularly preferred.

[0349] The weight average molecular weight (Mw) of the component (F) (in terms of polystyrene conversion based on gel permeation chromatography) is preferably from 1000 to 50000, more preferably from 5000 to 40000, and even more preferably from 10000 to 30000. When it is below the upper limit value of the above preferred range, there is sufficient solubility in the resist solvent for use as a resist, and when it is above the lower limit value of the above preferred range, the water repellency of the resist film is good. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and even more preferably from 1.0 to 2.5.

[0350] In the resist composition of the present embodiment, the component (F) may be used alone or in combination of two or more. When the resist composition contains the component (F), the content of the component (F) is usually used in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

[0351] << Organic solvent component (S) >> The resist composition of the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as the component (S)). As the component (S), any one can be appropriately selected from those known as solvents for chemically amplified resist compositions as long as it can dissolve each component used and form a uniform solution. Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, etc. of the polyhydric alcohols or the compounds having an ester bond, or compounds having an ether bond such as monophenyl ether, i.e., derivatives of polyhydric alcohols [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO), etc. In the resist composition of this embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds. Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0352] Also, as the component (S), a mixed solvent obtained by mixing 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, etc., but it is preferably in the range of 1:9 to 9:1, more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Further, when PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Additionally, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Also, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mixing ratio is preferably such that the mass ratio of the former to the latter is 70:30 to 95:5. The usage amount of the (S) component 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 (S) component is used so that the solid content concentration of the resist composition is within the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0353] In the resist composition of this embodiment, additives with miscibility as desired, such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc., can be appropriately added and contained.

[0354] After dissolving the above resist material in the (S) component, the resist composition of this embodiment may be subjected to removal of impurities or the like 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] In the resist composition of the present embodiment, the component (A) includes a resin component (A1) having a structural unit (a0), and the component (D) includes a specific photo-dissociable base (D0). The structural unit (a0) has an Ar (benzene ring or naphthalene ring) to which a hydroxy group is bonded at the side chain terminal, that is, a phenolic hydroxyl group (aromatic ring having a hydroxy group) that acts as a proton source. Further, in the structural unit (a0), due to the action of an acid, the bond between the oxygen atom (-O-) of the carbonyloxy group (C(=O)-O-) in the formula (a0-1) and the secondary carbon bonded to the oxygen atom (-O-) while forming a condensed ring structure with Ar is cleaved to generate a carbocation (the acid dissociable group dissociates). Thus, the structural unit (a0) has a protecting group with a so-called proton source function. By adopting such a structural unit (a0), the amount of the proton source can be increased without decreasing the density of the protecting group in the resist film (more proton sources and protecting groups can be present in the same volume). On the other hand, in the resist composition of the present embodiment, by adopting a photo-dissociable base instead of an amine quencher, the acid with an increased generation amount can be more efficiently utilized for the deprotection reaction. In addition, since the energy of the LUMO of the cation part in the photo-dissociable base (D0) to be adopted is -4.70 eV or less, the component (D0) is likely to receive electrons, and the cation part is more likely to decompose in the exposed part. As a result, in the formation of the resist pattern, unnecessary quenching in the exposed part is less likely to occur, and the deprotection reaction efficiency in the exposed part is enhanced. From the above, according to the resist composition of the present embodiment, due to the combined effects of these components (A1) and (D0), a resist pattern with enhanced sensitivity and reduced roughness can be formed.

[0356] (Resist pattern forming method) The method for forming a resist pattern according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the above-described embodiment, 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 using a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature condition of 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, for example, by exposure through a mask (mask pattern) on which a predetermined pattern is formed or by direct irradiation with an electron beam without using a mask pattern using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus. After that, a baking (post-exposure bake (PEB)) treatment is performed, for example, at a temperature condition of 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 alkali development process, water rinsing using 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-described development process. In this way, a resist pattern can be formed.

[0359] The support is not particularly limited, and conventionally known ones can be used. For example, substrates for electronic components and those with a predetermined wiring pattern formed thereon can be mentioned. More specifically, silicon wafers, metal substrates such as copper, chromium, iron, aluminum, and glass substrates can be mentioned. As the material for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used. In addition, as the support, an inorganic and / or organic film may be provided on the substrate as described above. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC) and organic films such as the lower organic film in the multilayer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the patterning of the lower organic film is performed using the resist pattern formed on the upper resist film as a mask, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, since the required thickness can be ensured by the lower organic film, the resist film can be made thinner, and the formation of a fine pattern with a high aspect ratio becomes possible. Basically, the multilayer resist method can be divided into a method with a two-layer structure of an upper resist film and a lower organic film (two-layer resist method) and a method with a multilayer structure of three or more layers in which one or more intermediate layers (such as a metal thin film) are provided between the upper resist film and the lower organic film (three-layer resist method).

[0360] The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F 2It can be carried out using radiation such as excimer lasers, EUV (extreme ultraviolet rays), VUV (vacuum ultraviolet rays), EB (electron beams), X-rays, and soft X-rays. The resist composition has high utility for KrF excimer lasers, ArF excimer lasers, EB, or EUV, higher utility for ArF excimer lasers, EB, or EUV, and particularly high utility for EB or EUV. That is, the resist pattern forming method of the present embodiment is a particularly useful method when the step of exposing the resist film includes an operation of exposing the resist film to EUV (extreme ultraviolet rays) or EB (electron beams).

[0361] The method of exposing 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, and exposure (immersion exposure) is performed in that state. As the liquid immersion medium, a solvent having a refractive index greater than that of air and smaller than that of the resist film to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range. Examples of the solvent having a refractive index greater than that of air and smaller than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Specific examples of fluorine-based inert liquids include C 3 HCl 2 F 5 、C 4 F 9 OCH 3 、C 4 F 9 OC 2 H 5 、C 5 H 3 F 7Examples of the liquid mainly composed of a fluorine-based compound include liquids, etc. Those having a boiling point of 70 to 180 °C are preferred, and those having a boiling point of 80 to 160 °C are more preferred. When the fluorine-based inert liquid has a boiling point within the above range, it is preferable because after the exposure is completed, the medium used for liquid immersion can be removed by a simple method. As the fluorine-based inert liquid, in particular, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is preferred. Specific examples of the perfluoroalkyl compound include perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102 °C), and examples of the perfluoroalkylamine compound include perfluorotributylamine (boiling point 174 °C). As the liquid immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, etc.

[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 solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and hydrocarbon solvents are included. A ketone solvent is an organic solvent containing C-C(=O)-C in its structure. An ester solvent is an organic solvent containing C-C(=O)-O-C in its structure. An alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in its structure. The "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. An amide solvent is an organic solvent containing an amide group in its structure. An ether solvent is an organic solvent containing C-O-C in its structure. Among organic solvents, there are also organic solvents containing a plurality of types of functional groups that characterize the above solvents in their structures. In such cases, it shall apply to any solvent type containing the functional groups of the organic solvent. For example, diethylene glycol monomethyl ether shall apply to both alcohol solvents and ether solvents in the above classification. Hydrocarbon solvents are composed of hydrocarbons that may be halogenated and are hydrocarbon solvents having no substituents other than halogen atoms. As the halogen atom, a fluorine atom is preferred. As the organic solvent contained in the organic developing solution, among the above, polar solvents are preferred, and ketone solvents, ester solvents, nitrile solvents, etc. are preferred.

[0363] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, as the ketone solvent, methyl amyl ketone (2-heptanone) is preferred.

[0364] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester solvent.

[0365] Examples of the nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitrile and the like.

[0366] Known additives can be incorporated into the organic developer as needed. Examples of the 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. As the surfactant, a non-ionic surfactant is preferable, and a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant is more preferable. When incorporating a surfactant, the incorporation amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the organic developer.

[0367] The development process can be carried out by a known development method. 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 still 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.

[0368] As the organic solvent contained in the rinse liquid used for the rinse treatment after the development treatment in the solvent development process, for example, among the organic solvents mentioned as the organic solvents 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. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, at least one selected from alcohol solvents and ester solvents is more preferable, and alcohol solvents are particularly preferable. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol and the like can be mentioned. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable. Any one of these organic solvents may be used alone, or two or more thereof may be used in combination. Further, it may be used in admixture with an organic solvent or water other than the above. However, considering the development characteristics, the blending amount of water in the rinse liquid is preferably 30% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 3% by mass or less with respect to the total amount of the rinse liquid. Known additives can be blended in the rinse liquid as required. Examples of the additive include a surfactant. Surfactants include the same ones as described above, and nonionic surfactants are preferable, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferable. When a surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid.

[0369] The rinsing treatment (cleaning treatment) using the rinse liquid can be carried out by a known rinsing method. Examples of the method of the rinsing treatment include a method of continuously coating 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 support surface (spray method), and the like.

[0370] According to the resist pattern forming method of the present embodiment described above, since the resist composition of the above-described embodiment is used, a resist pattern having high sensitivity and reduced roughness can be formed.

Example

[0371] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by these examples.

[0372] <Preparation of Resist Composition> (Examples 1 to 19, Comparative Examples 1 to 2) The components shown in Tables 1 and 2 were mixed and dissolved to prepare the resist compositions of each example, respectively.

[0373]

Table 1

[0374]

Table 2

[0375] In Tables 1 and 2, each abbreviation has the following meaning. The numerical values in [ ] are the blending amounts (parts by mass). (A)-1: A polymer compound represented by the following chemical formula (A1-1). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 7100, and the molecular weight dispersity (Mw / Mn) was 1.73. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50. (A)-2: A polymer compound represented by the following chemical formula (A1-2). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 6600, and the molecular weight dispersity (Mw / Mn) was 1.68. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50. (A)-3: A polymer compound represented by the following chemical formula (A1-3). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 6600, and the molecular weight dispersity (Mw / Mn) was 1.68. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50. (A)-4: A polymer compound represented by the following chemical formula (A1-4). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6900, and the molecular weight distribution (Mw / Mn) is 1.67. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m = 50 / 50. (A)-5: A polymer compound represented by the following chemical formula (A1-5). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7000, and the molecular weight distribution (Mw / Mn) is 1.67. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m = 50 / 50. (A)-6: A polymer compound represented by the following chemical formula (A1-6). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7000, and the molecular weight distribution (Mw / Mn) is 1.67. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m = 50 / 50. (A)-7: A polymer compound represented by the following chemical formula (A1-7). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6800, and the molecular weight distribution (Mw / Mn) is 1.70. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m = 50 / 50. (A)-8: A polymer compound represented by the following chemical formula (A1-8). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7100, and the molecular weight distribution (Mw / Mn) is 1.73. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m = 50 / 50. (A)-9: A polymer compound represented by the following chemical formula (A1-9). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6800, and the molecular weight distribution (Mw / Mn) is 1.69. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m / n = 45 / 45 / 10. (A)-10: A polymer compound represented by the following chemical formula (A1-10). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7,100, and the molecular weight distribution (Mw / Mn) is 1.67. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m / n = 45 / 45 / 10. (A)-11: A polymer compound represented by the following chemical formula (A2-1). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6,600, and the molecular weight distribution (Mw / Mn) is 1.66. 13 The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by 13C-NMR is l / m = 50 / 50.

[0376]

Chemical formula

[0377]

Chemical formula

[0378] (B)-1: An acid generator composed of a compound represented by the following chemical formula (B1-1).

[0379]

Chemical formula

[0380] (D)-1: A photo-dissociable base composed of a compound represented by the following chemical formula (D0-1). The energy of the LUMO of the cationic part is -4.99 eV. (D)-2: A photo-dissociable base composed of a compound represented by the following chemical formula (D0-2). The energy of the LUMO of the cationic part is -5.00 eV. (D)-3: A photo-dissociable base composed of a compound represented by the following chemical formula (D0-3). The energy of the LUMO of the cationic part is -5.10 eV. (D)-4: A photodecomposable base composed of a compound represented by the following chemical formula (D0-4). The energy of the LUMO of the cation part is -5.21 eV. (D)-5: A photodecomposable base composed of a compound represented by the following chemical formula (D0-5). The energy of the LUMO of the cation part is -5.24 eV. (D)-6: A photodecomposable base composed of a compound represented by the following chemical formula (D0-6). The energy of the LUMO of the cation part is -5.27 eV. (D)-7: A photodecomposable base composed of a compound represented by the following chemical formula (D0-7). The energy of the LUMO of the cation part is -5.35 eV. (D)-8: A photodecomposable base composed of a compound represented by the following chemical formula (D0-8). The energy of the LUMO of the cation part is -5.39 eV. (D)-9: A photodecomposable base composed of a compound represented by the following chemical formula (D0-9). The energy of the LUMO of the cation part is -5.51 eV. (D)-10: A photodecomposable base composed of a compound represented by the following chemical formula (D0-10). The energy of the LUMO of the cation part is -5.54 eV.

[0381]

Chemical formula

[0382] (D)-11: A photodecomposable base composed of a compound represented by the following chemical formula (D1-1). The energy of the LUMO of the cation part is -4.68 eV.

[0383]

Chemical formula

[0384] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0385] <Formation of resist pattern> On an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS), each resist composition of each example was applied using a spinner, and prebaked (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 30 nm. Next, using an electron beam lithography apparatus JEOL-JBX-9300FS (manufactured by JEOL Ltd.), the resist film was exposed (lithographed) at an acceleration voltage of 100 kV with a target size of a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a line width ranging from 50 nm to 16 nm. Thereafter, post-exposure baking (PEB) was performed at 90°C for 60 seconds. Subsequently, at 23°C, an alkali development was performed for 60 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, a water rinse was performed for 15 seconds using pure water. As a result, a 1:1 LS pattern with a line width ranging from 50 nm to 16 nm was formed.

[0386] [Evaluation of Optimum Exposure Dose (Eop)] The optimum exposure dose Eop (μC / cm 2 ) at which the LS pattern of the target size was formed by the above <Formation of Resist Pattern> was determined. This is shown in Tables 3 to 4 as "Eop (μC / cm 2 )".

[0387] [Evaluation of Line-Width Roughness (LWR)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, which is a measure indicating LWR, was determined. This is shown in Tables 3 to 4 as "LWR (nm)". "3σ" is the triple value (3σ) (unit: nm) of the standard deviation (σ) obtained by measuring the line positions at 400 locations in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage: 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the value of 3σ, the smaller the roughness of the line sidewall, meaning that an LS pattern with a more uniform width was obtained.

[0388]

Table 3

[0389]

Table 4

[0390] From the results shown in Tables 3 and 4, it can be confirmed that the resist compositions of Examples 1 to 19 can achieve increased sensitivity and form resist patterns with excellent lithography characteristics.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising: a resin component (A1) whose solubility in a developer changes due to the action of an acid; a photo-dissociable base (D0) that controls the diffusion of the acid generated upon exposure; an acid generator component (B) that generates an acid upon exposure; and the resin component (A1) has a structural unit (a0) represented by the following general formula (a0-1); the photo-dissociable base (D0) has an anion part and a cation part, and is a compound in which the energy of the LUMO of the cation part is -4.90 eV or less (however, excluding quencher 1 represented by the following structural formula), the resist composition. 【Chemical 1】 [In the formula, R ０１ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Ya ０１ is a single bond or a divalent linking group. Ar is a benzene ring or a naphthalene ring. m01 is an integer of 0 to 6. n01 is an integer of 1 to 4 as long as the valence allows.] 【Chemical 2】

2. The resist composition according to claim 1, wherein the energy of the LUMO of the cation part in the photo-dissociable base (D0) is -5.20 eV or less.

3. The resist composition according to claim 1 or 2, wherein the anion part in the photo-dissociable base (D0) is an anion represented by the following general formula (d0-an1). [Chemical Formula 3] [wherein, Rd １ 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.]

4. A resist pattern forming method comprising: a step of forming a resist film using the resist composition according to any one of claims 1 to 3 on a support; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

5. The resist pattern forming method according to claim 4, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet light) or EB (electron beam).

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