JP2020066740A - Compound, resin, resist composition, and method for producing resist pattern - Google Patents

Abstract

To produce a resist pattern having good CD uniformity.SOLUTION: A compound of formula (I) and a resist composition are provided. [In the formula, Rrepresents H or a methyl group; Rand Reach represent formula (1a) or formula (2a); R, Rand Reach represent an alkyl group; naa represents 0 or 1; Rand Reach represent H or an alkyl group; Rrepresents an alkyl group; Xrepresents O or S; and R, Rand Reach represent H, a halogen atom, a hydroxy group, an alkyl group, an alkoxy group or the like.]SELECTED DRAWING: None

Description

  The present invention relates to a compound, a resin, a resist composition, a method for producing a resist pattern using the resist composition, and the like.

Patent Document 1 describes a resist composition containing a resin having a structural unit derived from the following compound.
Patent Document 2 describes a resist composition containing a resin having a structural unit derived from the following compound.

JP-A-8-337616 JP, 2005-091712, A

  The present invention provides a compound which forms a resist pattern having better CD uniformity (CDU) than a resist pattern formed by a resist composition containing a resin containing a structural unit derived from the above compound.

The present invention includes the following inventions.
[1] A compound represented by the formula (I).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ³ represents a hydrogen atom, a group represented by the formula (1a) or a group represented by the formula (2a).
R ⁴ represents a group represented by the formula (1a) or a group represented by the formula (2a).
[In Formula (1a), R ^aa1 , R ^aa2, and R ^aa3 each independently represent an alkyl group having 1 to 8 carbon atoms.
naa represents 0 or 1.
* Represents a bond. ]
[In the formula (2a), R ^{aa1 ′} and R ^{aa2 ′} each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R ^{aa3 ′} represents an alkyl group having 1 to 8 carbon atoms, -CH ₂ contained in the alkyl group - may be replaced by -O- or -S-.
X ^c represents an oxygen atom or a sulfur atom.
* Represents a bond. ]
R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an alkylcarbonyloxy group having 1 to 6 carbon atoms. Represents a group. ]
[2] The compound according to [1], wherein R ³ is a group represented by formula (1a) or a group represented by formula (2a).
[3] A resin containing a structural unit derived from the compound according to [1] or [2].
[4] The resin according to [3], further including a structural unit having an acid labile group other than the structural unit derived from the compound represented by the formula (I).
[5] A resist composition containing the resin according to [3] or [4] and an acid generator.
[6] The resist composition according to [5], wherein the acid generator contains a salt represented by the formula (B1).
[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent and is contained in the alicyclic hydrocarbon group; CH ₂ - is, -O -, - S (O ) 2 - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]
[7] The resist composition according to [5] or [6], further containing a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[8] (1) A step of applying the resist composition according to any one of [5] to [7] onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) exposing the composition layer
A method for producing a resist pattern, comprising the step of (4) heating the composition layer after exposure, and (5) developing the composition layer after heating.

  By using a resist composition using a resin containing a structural unit derived from the compound of the present invention, a resist pattern can be produced with good CD uniformity (CDU).

In the present specification, unless otherwise specified, the “(meth) acrylate” means “at least one selected from the group consisting of acrylate and methacrylate”. The expressions such as “(meth) acrylic acid” and “(meth) acryloyl” have the same meaning. If _{"CH 2 = C (CH 3)} -CO- " or "CH ₂ = CH-CO-" structural unit having a are illustrated, structural units having both groups are exemplified similarly I shall. Further, in the groups described in the present specification, any of those having both a linear structure and a branched structure may be used. The “combined group” means a group in which two or more kinds of the exemplified groups are bonded, and the valence of these groups may be appropriately changed depending on the bonding form. When stereoisomers are present, all stereoisomers are included.
In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described below from the total amount of the resist composition.

[Compound represented by Formula (I)]
The compound of the present invention relates to a compound represented by the formula (I) (hereinafter sometimes referred to as "compound (I)").
In formula (I), the alkyl group represented by R ^aa , R ^aa2 , R ^aa3 and R ^{aa1 ′} , R ^{aa2 ′} and R ^{aa3 ′} of the formula (1a) and the formula (2a) in R ³ and R ⁴ is , Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group and the like.
naa is preferably 1.
X ^c is preferably an oxygen atom.

Examples of the group represented by the formula (1a) include the following groups. * Represents a bond.
Among them, a group represented by the formula (1a) is a group represented by the formula ^(I-R 2 -1-1) or formula ^(I-R 2 -1-2) are preferred.

Examples of the group represented by the formula (2a) include the following groups. * Represents a bond.
Among them, a group represented by the formula (2a) has the formula ^(I-R 2 -2-1), in the formula ^(I-R 2 -2-2) or formula ^(I-R 2 -2-5) The groups represented are preferred.
R ³ is preferably a group represented by formula (1a) or a group represented by formula (2a). Further, R ³ and R ⁴ may be different groups, but are preferably the same group.

Examples of the alkyl group having 1 to 6 carbon atoms of R ⁵ , R ⁶ and R ⁷ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group and a hexyl group. An alkyl group is mentioned. The carbon number of the alkyl group is preferably 1 to 4.
Examples of the alkoxy group having 1 to 6 carbon atoms of R ⁵ , R ⁶ and R ⁷ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 4.
Examples of the alkylcarbonyloxy group having 1 to 6 carbon atoms of R ⁵ , R ⁶ and R ⁷ include an acetyloxy group, a propionyloxy group and a butyryloxy group.
Examples of the halogen atom of R ⁵ , R ⁶ and R ⁷ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Among them, R ⁵ , R ⁶ and R ⁷ are preferably hydrogen atoms.

Examples of the compound (I) include the following compounds.

Compounds represented by formula (I-1) to formula (I-25) in which a methyl group corresponding to R ¹ in formula (I) is replaced with a hydrogen atom are also mentioned as specific examples of compound (I). be able to. Among them, the compounds represented by formula (I-1) to formula (I-6) and formula (I-19) to formula (I-21) are preferable.

<Method for producing compound (I)>
The compound (I) is obtained by reacting the compound represented by the formula (Ia) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by the formula (Ib). be able to.
(In the formula, all symbols have the same meanings as described above.)

Examples of the solvent include tetrahydrofuran, chloroform, acetonitrile and the like.
The reaction temperature is generally 0 ° C to 80 ° C, and the reaction time is generally 0.5 hr to 24 hr.
Examples of the compound represented by the formula (Ia) include compounds represented by the following formulas, which can be easily obtained from the market.

Examples of the compound represented by the formula (Ib) include compounds represented by the following formulas, which can be easily obtained from the market.

〔resin〕
The resin of the present invention is a resin (hereinafter sometimes referred to as “resin (A)”) containing a structural unit derived from compound (I) (hereinafter sometimes referred to as “structural unit (I)”). The resin (A) may be a homopolymer of the structural unit (I), may be a copolymer consisting only of the structural unit (I), or contains one or more structural units other than the structural unit (I). It may be a polymer. As the structural unit other than the structural unit (I), a structural unit having an acid labile group other than the structural unit (I) (hereinafter sometimes referred to as “structural unit (a1)”), a structural unit having an acid labile group Other structural units having a halogen atom (hereinafter sometimes referred to as “structural unit (a4)”) and structural units having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) A), a structural unit having a non-eliminating hydrocarbon group (hereinafter sometimes referred to as “structural unit (a5)”), and the like. Here, the acid labile group means a group having a leaving group, and the leaving group is released upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group).
The content of the structural unit (I) is usually 5 to 90 mol%, preferably 5 to 80 mol%, and more preferably 7 to 50 mol% based on all the monomers in the resin (A). .
When the resin (A) contains a structural unit represented by the formula (a4) and / or (a5) described later (hereinafter sometimes referred to as “resin (AX)”), the structure of the resin (AX) of the present invention. The content of the unit (I) is preferably 5 to 75 mol%, more preferably 10 to 70 mol%, and further preferably to the total of all structural units of the resin (AX) of the present invention. It is 10 to 65 mol%, particularly preferably 10 to 60 mol%. The resin (AX) may be used instead of the resin (A) or may be used in combination with the resin (A).

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
The acid labile group contained in the resin (A) is a group represented by the formula (1) (hereinafter, also referred to as the group (1)) and / or a group represented by the formula (2) (hereinafter, the group (2 ) Is also preferable).
[In Formula (1), R ^a1 , R ^a2, and R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group in which these are combined. That is, R ^a1 and R ^a2 are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1.
* Represents a bond. ]
[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. Or R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and are included in the hydrocarbon group and the heterocyclic group. CH ₂ - may be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na 'represents 0 or 1.
* Represents a bond. ]

^Examples of the alkyl group in R ^a1 , R ^a2 and R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group and an octyl group.
The alicyclic hydrocarbon group for R ^a1 , R ^a2 and R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^a1 , R ^a2 and R ^a3 preferably has 3 to 16 carbon atoms.
Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group. Examples thereof include an ethyl group.
Preferably, ma is 0 and na is 1.
The following groups are mentioned as -C (R ^a1 ) (R ^a2 ) (R ^a3 ) when R ^a1 and R ^a2 are bonded to each other to form an alicyclic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the hydrocarbon group for R ^{a1 ′} , R ^{a2 ′,} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those mentioned for R ^a1 , R ^a2 and R ^a3 .
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group and phenanthryl group.
Examples of the combined group include a group in which the above-described alkyl group and an alicyclic hydrocarbon group are combined (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methyl group). Phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), alicyclic hydrocarbon group Examples thereof include aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and aryl-cycloalkyl groups such as phenylcyclohexyl group.
When R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a heterocyclic group with the carbon atom to which they are bonded and X, —C (R ^{a1 ′} ) (R ^{a2 ′} ) —X—R ^{a3 ′} is: The following groups may be mentioned. * Represents a bond.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.
na ′ is preferably 0.

Examples of the group (1) include the following groups.
A group in which R ^a1 , R ^a2, and R ^a3 in the formula (1) are alkyl groups, ma = 0 and na = 1. The group is preferably a tert-butoxycarbonyl group.
In the formula (1), R ^a1 and R ^a2 together with the carbon atom to which they are bonded form an adamantyl group, R ^a3 is an alkyl group, ma = 0 and na = 1. .
In the formula (1), R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma = 0, and na = 1.
Specific examples of the group (1) include the following groups. * Represents a bond.

Specific examples of the group (2) include the following groups. * Represents a bond.

  The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. When the resin (A) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

As the structural unit derived from the (meth) acrylic monomer having the group (1), a structural unit represented by the formula (a1-0) (hereinafter, sometimes referred to as the structural unit (a1-0)), a formula ( The structural unit represented by a1-1) (hereinafter sometimes referred to as the structural unit (a1-1)) or the structural unit represented by the formula (a1-2) (hereinafter referred to as the structural unit (a1-2). There are some cases). . Preferably, it is at least one structural unit selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). These may be used alone or in combination of two or more.
[In Formula (a1-0), Formula (a1-1), and Formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents Represents a bond with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents an integer of 0 to 14.
n1 represents any integer of 0-10.
n1 ′ represents an integer of 0 to 3. ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^a01 , L ^a1 and L ^a2 are preferably oxygen atoms or * —O— (CH ₂ ) _k01 —CO—O— (however, k01 is preferably an integer of 1 to 4, more preferably Is 1.), more preferably an oxygen atom.
Examples of the alkyl group in R ^a02 , R ^a03 , R ^a04 , R ^a6, and R ^a7 , the alicyclic hydrocarbon group, and a group in which these groups are combined include the groups listed for R ^a1 , R ^a2, and R ^a3 in the formula (1). And the same groups as.
The alkyl group in R ^a02 , R ^a03 , and R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
The alkyl group in R ^a6 and R ^a7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group or an isopropyl group, and further preferably an ethyl group or an isopropyl group.
The carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably 5 to 12, and more preferably 5 to 10.
The group in which an alkyl group and an alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in which these alkyl groups and an alicyclic hydrocarbon group are combined.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
R ^a6 and R ^a7 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group or an isopropyl group, and still more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

Examples of the structural unit (a1-0) include structural units represented by any of the formulas (a1-0-1) to (a1-0-12) and R ^a01 in the structural unit (a1-0). Structural units in which the corresponding methyl groups are replaced by hydrogen atoms are mentioned, and structural units represented by any of the formulas (a1-0-1) to (a1-0-10) are preferable.

Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP2010-204646A. Among them, the structural unit represented by any of the formulas (a1-1-1) to (a1-1-4) and the methyl group corresponding to R ^a4 in the structural unit (a1-1) were replaced with hydrogen atoms. The structural unit is preferable, and the structural unit represented by any of the formulas (a1-1-1) to (a1-1-4) is more preferable.

The structural unit (a1-2) corresponds to the structural unit represented by any of the formulas (a1-2-1) to (a1-2-6) and R ^a5 in the structural unit (a1-2). A structural unit in which a methyl group is replaced with a hydrogen atom can be given, and a structural unit represented by any one of formula (a1-2-2), formula (a1-2-5) and formula (a1-2-6) is preferable.

When the resin (A) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content of these is the total structure of the resin (A). For units,
It is usually 10 to 95 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol%, still more preferably 25 to 75 mol%, still more preferably 30 to 70 mol%. Is.

Examples of the structural unit having the group (2) in the structural unit (a1) include structural units represented by the formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). .
[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl It represents an oxy group or a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, a plurality of R ^a33 may be the same as or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 may represent a hydrocarbon group having 1 to 20 carbon atoms, R ^a35 and R ^a36 are bonded to each other And form a divalent hydrocarbon group having 2 to 20 carbon atoms with —C—O— to which they are bonded, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group is — It may be replaced with O- or -S-. ]

^Examples of the alkyl group in R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
Examples of the halogen atom in R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, 1,1, 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,3 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. Can be mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
As the hydrocarbon group for R ^a34, R ^a35 and R ^a36, an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group and a group formed by combining these.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group and an octyl group.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, the following groups (* represents a bonding site) and the like.
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group and phenanthryl group.
Examples of the combined group include a group in which the above-described alkyl group and an alicyclic hydrocarbon group are combined (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methyl group). Phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), alicyclic hydrocarbon group Examples thereof include aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and aryl-cycloalkyl groups such as phenylcyclohexyl group. In particular, R ^a36 is an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. Is mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
As R ^a33 , an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is further preferable.
As la, 0 or 1 is preferable, and 0 is more preferable.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group, and more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. The group formed is more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group for R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group for R ^a36 is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

^{-OC (R a34) (R a35} ) -O-R a36 in the structural unit (a1-4) is desorbed by contact with an acid (e.g. p- toluenesulfonic acid) to form a hydroxy group.
Examples of the structural unit (a1-4) include structural units derived from a monomer described in JP 2010-204646 A. Preferably, hydrogen atom corresponding to the structural units and ^{R a32} each represented by formula (a1-4-1) ~ formula (a1-4-12) are exemplified a structural unit replacing a methyl group, more preferably , Structural units represented by formula (a1-4-1) to formula (a1-4-5) and formula (a1-4-10), respectively.
When the resin (A) has the structural unit (a1-4), its content is preferably 5 to 60 mol% based on the total of all structural units of the resin (A), and 5 to 50 mol%. It is more preferably mol%, and further preferably 10 to 40 mol%.

Examples of the structural unit derived from the (meth) acrylic monomer having the group (2) also include a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”). To be
In formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or _{* - (CH 2) h3 -CO} -L 54 - represents, h3 represents an integer of 1 to 4, * represents a bond to L ^51.
L ^51, L ^52, L ⁵³ and L ⁵⁴ each independently represents -O- or -S-.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom 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 fluoromethyl group and trifluoromethyl. Groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
It is preferable that one of L ⁵² and L ⁵³ is —O— and the other is —S—.
s1 is preferably 1.
s1 ′ is preferably an integer of 0-2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the structural unit (a1-5) include structural units derived from the monomers described in JP 2010-61117 A. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and each is represented by formula (a1-5-1) or formula (a1-5-2). Structural units are more preferred.
When the resin (A) has the structural unit (a1-5), its content is preferably 1 to 50 mol% and more preferably 3 to 45 mol% with respect to the total structural units of the resin (A). , 5 to 40 mol% is more preferable, and 5 to 30 mol% is even more preferable.

Examples of the structural unit (a1) also include a structural unit represented by the formula (a1-0X) (hereinafter sometimes referred to as structural unit (a1-0X)).
[In the formula (a1-0X),
R ^x1 represents a hydrogen atom or a methyl group.
R ^x2 and R ^x3 each independently represent a saturated hydrocarbon group having 1 to 6 carbon atoms.
Ar ^x1 represents an aromatic hydrocarbon group having 6 to 36 carbon atoms. ]

Examples of the saturated hydrocarbon group for R ^x2 and R ^x3 include an alkyl group, an alicyclic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl 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, a pentyl group and a hexyl group.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group.

Examples of the aromatic hydrocarbon group of Ar ^x1 include aryl groups having 6 to 36 carbon atoms such as a phenyl group, a naphthyl group, and an anthryl group.
The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, and still more preferably a phenyl group.
Ar ^x1 is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, more preferably a phenyl group or a naphthyl group, and further preferably a phenyl group.
R ^x1 , R ^x2, and R ^x3 are each independently preferably a methyl group or an ethyl group, and more preferably a methyl group.

Examples of the structural unit (a1-0X) include a structural unit (a structural unit (a1-0X) in which a methyl group corresponding to R ^x1 in the structural unit (a1-0X) is replaced with a hydrogen atom. 0X) is preferably a structural unit (a1-0X-1) to a structural unit (a1-0X-3).
When the resin (A) has the structural unit (a1-0X), its content is preferably 5 to 60 mol%, and preferably 5 to 50 mol%, based on all the monomers in the resin (A). It is more preferable that the amount is 10 to 40 mol%.
The resin (A) may contain two or more types of structural units (a1-0X).

The structural unit (a1) also includes the following structural units.
When the resin (A) contains the above structural unit, the content thereof is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and more preferably 10 to 40 mol, based on all the structural units of the resin (A). % Is more preferable.

<Structural unit (s)>
As the monomer leading to the structural unit (s), a monomer having no acid labile group known in the resist field can be used.
The structural unit (s) preferably has a hydroxy group or a lactone ring. A structural unit having a hydroxy group and not having an acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a lactone ring and having no acid labile group When a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, when a high energy ray such as KrF excimer laser (248 nm), electron beam or EUV (ultraviolet light) is used as an exposure light source, the structural unit (a2) is used. It is preferable to use the structural unit (a2) having a phenolic hydroxy group. When using an ArF excimer laser (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and the structural unit (a2-1) described later is more preferable. preferable. As the structural unit (a2), one type may be used alone, or two or more types may be used.

Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include structural units represented by the formula (a2-A) (hereinafter sometimes referred to as “structural unit (a2-A)”).
[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, or acryloyl. It represents an oxy group or a methacryloyloxy group.
A ^a50 represents a single bond or ^{* -X a51 - (A a52 -X} a52) nb - represents, * represents a bond to the carbon atom to which -R ^a50 binds.
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent —O—, ^—CO —O— or —O—CO—.
nb represents 0 or 1.
mb represents the integer in any one of 0-4. When mb is any integer greater than or equal to 2, some R ^<a51> may mutually be same or different. ]

^Examples of the halogen atom for R ^a50 include a fluorine atom, a chlorine atom and a bromine atom.
^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R ^a50 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1 , 1,2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl group Groups.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, still more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group for R ^a51 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl group.
^Examples of the alkoxy group in R ^a51 include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. An alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
^Examples of the alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group and a butyryl group.
^Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group and a butyryloxy group.
R ^a51 is preferably a methyl group.

^{* -X a51 - (A a52 -X} a52) nb - The, * - O -, * - CO-O -, * - O-CO -, * - CO-O-A a52 -CO-O-, * -O-CO-A ^a52 -O-, * -O-A ^a52 -CO-O-, * -CO-O-A ^a52 -O- ^CO- , * -O-CO-A ^a52 -O-CO -, And the like. Among them, * -CO-O-, * -CO-O- ^Aa52- CO-O- or * -O- ^Aa52- CO-O- is preferable.
Examples of the alkanediyl group include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -Methylbutane-1,4-diyl group and the like.
A ^a52 is preferably a methylene group or an ethylene group.
A ^a50 is preferably a single bond, * -CO-O- or * -CO-O-A ^a52 -CO-O-, and a single bond, * -CO-O- or * -CO-O-CH. _2- CO-O- is more preferred, and a single bond or * -CO-O- is even more preferred.
mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxy group is preferably bonded to the ortho position or para position of the benzene ring, more preferably to the para position.

Examples of the structural unit (a2-A) include structural units derived from monomers described in JP2010-204634A and JP2012-12577A.
As the structural unit (a2-A), the structural unit represented by the formula (a2-2-1) to the formula (a2-2-6), and the formula (a2-2-1) to the formula (a2-2-). ^Examples of the structural unit represented by 6) include a structural unit in which a methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom. The structural unit (a2-A) is represented by the structural unit represented by the formula (a2-2-1), the structural unit represented by the formula (a2-2-3), and the structural unit (a2-2-6). In the structural unit represented by the formula (a2-2-1), the structural unit represented by the formula (a2-2-3) or the structural unit represented by the formula (a2-2-6), It is preferable that the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom.

When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol% with respect to all structural units, and more preferably It is 10 to 70 mol%, more preferably 15 to 65 mol%, and even more preferably 15 to 50 mol%.
The structural unit (a2-A) can be contained in the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Further, the structural unit (a2-A) can be contained in the resin (A) by polymerizing with acetoxystyrene or the like and then treating with an alkali such as tetramethylammonium hydroxide.

Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include structural units represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).
In formula (a2-1),
L ^a3 represents -O- or ^* -O- (CH ₂ ) _k2- CO-O-,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents any integer of 0-10.

In Formula (a2-1), L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O— (wherein f1 represents any integer of 1 to 4). , And more preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the structural unit (a2-1) include structural units derived from the monomers described in JP 2010-204646 A. The structural unit represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and the structural unit represented by any of the formulas (a2-1-1) to (a2-1-4) is preferable. The structural unit represented is more preferable, and the structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is further preferable.
When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol%, preferably 1 to 40 mol% with respect to the total structural units of the resin (A). %, More preferably 1 to 35 mol%, further preferably 2 to 20 mol%, and still more preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring contained in the structural unit (a3) may be a single ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But it's okay. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) is mentioned.

The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4). These may be contained alone or in combination of two or more.
[In Formula (a3-1), Formula (a3-2), Formula (a3-3), and Formula (a3-4),
L ^a4 , L ^a5 and L ^a6 are each independently represented by —O— or * —O— (CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). Represents a group.
L ^{a7 is, -O -, * - O-} L a8 -O -, * - O-L a8 -CO-O -, * - O-L a8 -CO-O-L a9 -CO-O- or * -O- ^La8- O-CO- ^La9- O- is represented.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* Represents a binding site to the carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
X ^a3 is, -CH ₂ - represents an or an oxygen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer of 0-5.
q1 represents an integer of 0 to 3.
r1 represents an integer of 0 to 3.
w1 represents any integer of 0-8.
When p1, q1, r1 and / or w1 are 2 or more, a plurality of R ^a21 , R ^a22 , R ^a23 and / or R ^a25 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group for R ^a21 , R ^a22 , R ^a23 and R ^a25 include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group and a tert-butyl group. To be
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group for R ^a24 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl group, and preferably have 1 to 4 carbon atoms. And an alkyl group are more preferable, and a methyl group or an ethyl group is more preferable.
Examples of the alkyl group having a halogen atom in R ^a24 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group and a perfluoro group. Hexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like can be mentioned.
^Examples of the alkanediyl group in L ^a8 and L ^a9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples thereof include 4-diyl group and 2-methylbutane-1,4-diyl group.

In formulas (a3-1) to (a3-3), L ^{a4 to} L ^a6 are each independently, preferably —O— or * —O— (CH ₂ ) _k3— CO—O—, k3. group but is any integer of 1 to 4, more preferably -O- _{and, * - O-CH 2 -CO} -O-, more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, and more preferably 0 or 1.
In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group. Is.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or ^{* -O-L} a8 -CO-O-, more preferably an _{-O -, - O-CH 2} -CO-O- or _-O-C 2 _{H 4} - It is CO-O-.
w1 is preferably an integer of 0 to 2, and more preferably 0 or 1.
Particularly, the formula (a3-4) is preferably the formula (a3-4) ′.
(In the formula, R ^a24 and L ^a7 have the same meanings as described above.)

As the structural unit (a3), a structure derived from the monomer described in JP-A-2010-204646, the monomer described in JP-A-2000-122294, and the monomer described in JP-A-2012-41274. Units are mentioned. As the structural unit (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-). 1), the structural unit represented by any of the formula (a3-3-2) and the formula (a3-4-1) to the formula (a3-4-12), and the structural unit represented by the formula (a3-1). ) To formula (a3-4), a structural unit in which a methyl group corresponding to R ^a18 , R ^a19 , R ^a20, and R ^a24 in the formula (a3-4) is replaced with a hydrogen atom is preferable.
When the resin (A) contains the structural unit (a3), the total content thereof is usually 1 to 70 mol%, preferably 1 to 65 mol% with respect to the total structural units of the resin (A). , And more preferably 1 to 60 mol%.
In addition, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is, based on the total structural units of the resin (A), respectively. 1 to 60 mol% is preferable, 1 to 50 mol% is more preferable, and 1 to 50 mol% is further preferable.

<Structural unit (a4)>
Examples of the structural unit (a4) include the following structural units.
[In the formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having a fluorine atom having 1 to 24 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO. ]
Examples of the saturated hydrocarbon group represented by R ⁴² include a chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these.

The chain hydrocarbon group includes 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, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group and an octadecyl group. Can be mentioned.
Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups. (* Represents a bond) and other polycyclic alicyclic hydrocarbon groups.
Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, and -alkanediyl group- Examples thereof include an alicyclic hydrocarbon group, an alicyclic hydrocarbon group, an alkyl group, an alkanediyl group, an alicyclic hydrocarbon group and an alkyl group.

The structural unit (a4) is at least selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4). The structural unit represented by one is mentioned.
[In the formula (a4-0),
R ^5a represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
L ^3a represents a C 1-8 perfluoroalkanediyl group or a C 3-12 perfluorocycloalkanediyl group.
R ^6a represents a hydrogen atom or a fluorine atom. ]

The alkanediyl group for L ^4a includes a straight-chain alkanediyl group such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, ethane-1,1-diyl group, Examples include branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group. To be
^Examples of the perfluoroalkanediyl group in L ^3a include a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group and a perfluoropropane. -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluoro Tan-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluoro Octane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like can be mentioned.
^Examples of the perfluorocycloalkanediyl group in L ^3a include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

L ^4a is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ^3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include a structural unit shown below and a structural unit in which a methyl group corresponding to R ^5a in the structural unit (a4-0) in the following structural units is replaced with a hydrogen atom.

[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO—. May be.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.
[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a single bond or a substituent.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O— or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* Is a bond, and * on the right is a bond with -O-CO- ^Ra42 . ]

^Examples of the saturated hydrocarbon group for R ^a42 include a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these.
Examples of the chain saturated hydrocarbon group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group. Is mentioned.
Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and Examples thereof include polycyclic alicyclic saturated hydrocarbon groups such as groups (* represents a bond).
Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more saturated alicyclic hydrocarbon groups, and an -alkanediyl group. -Saturated alicyclic hydrocarbon group, -saturated alicyclic hydrocarbon group-alkyl group, -alkanediyl group-saturated alicyclic hydrocarbon group-alkyl group and the like.

^Examples of the substituent that R ^a42 may have include at least one selected from a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, **-O-CO-, or **-CO-O- (** represents a bond with R ^a42 ).
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* Represents a bond. ]
However, in R ^a42 -X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.

^Examples of the aliphatic hydrocarbon group for A ^a45 include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and Alkyl group such as octadecyl group;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond) .) And other polycyclic alicyclic hydrocarbon groups.
Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, and -alkanediyl group- Examples thereof include an alicyclic hydrocarbon group, an alicyclic hydrocarbon group, an alkyl group, an alkanediyl group, an alicyclic hydrocarbon group and an alkyl group.

R ^a42 is preferably a saturated hydrocarbon group which may have a halogen atom, and more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by the formula (a-g3).
When R ^a42 is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, further preferably a carbon number of 1 to 1 A perfluoroalkyl group having 6 carbon atoms, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group and the like.
When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), the total carbon number of R ^a42 including the number of carbon atoms contained in the group represented by formula (a-g3). The number is preferably 15 or less, more preferably 12 or less. When the group represented by formula (a-g3) has a substituent, the number thereof is preferably 1.

When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R ^a42 is more preferably a group represented by formula (a-g2).
[In the formula (a-g2),
A ^a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
^Xa44 represents **-O-CO- or **-CO-O- (** represents a bond with ^Aa46 ).
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond with the carbonyl group. ]

1-6 are preferable and, as for carbon number of the saturated hydrocarbon group of ^Aa46 , 1-3 are more preferable.
The aliphatic hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and A ^a47 is more preferably a cyclohexyl group or an adamantyl group.

A preferred structure of the group represented by formula (a-g2) is the following structure (* represents a bond with a carbonyl group).

The alkanediyl group for A ^a41 includes a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group. A linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples thereof include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group represented by A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

The divalent saturated hydrocarbon group represented by A ^a42 , A ^a43 and A ^{a44 in} the group represented by the formula (a-g1) includes a linear or branched alkanediyl group and a monocyclic or polycyclic divalent group. Examples thereof include an alicyclic hydrocarbon group, and a group formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the divalent saturated hydrocarbon group represented by A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

^{Examples of the} group represented by the formula (a-g1) in which X ^a42 is —O—, ^—CO— , ^—CO —O— or —O—CO— include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with -O-CO- ^Ra42 .

Examples of the structural unit represented by the formula (a4-1) include a structural unit shown below and a methyl group corresponding to R ^a41 in the structural unit represented by the formula (a4-1) in the following structural unit is a hydrogen atom. Included are the replaced structural units.

As the structural unit represented by formula (a4-1), the structural unit represented by formula (a4-2) is preferable.
[In the formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ⁴⁴ represents an alkanediyl group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced with —O— or —CO—.
R ^f6 represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms.
However, the upper limit of the total carbon number of L ⁴⁴ and R ^f6 is 21. ]

^Examples of the alkanediyl group of L ⁴⁴ include the same groups as those exemplified for A ^a41 .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as those exemplified for R ^a42 .
As the alkanediyl group for L ^44, an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.

Examples of the structural unit represented by the formula (a4-2) include structural units represented by the formula (a4-1-1) to the formula (a4-1-11). A structural unit in which a methyl group corresponding to R ^f5 in the structural unit (a4-2) is replaced with a hydrogen atom is also included as the structural unit represented by the formula (a4-2).

[In formula (a4-3),
R ^f7 represents a hydrogen atom or a methyl group.
L ⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.
^Xf12 represents * -O-CO- or * -CO-O- (* represents a bond with ^Af13 ).
A ^f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms, which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom, and the upper limit of the total carbon number of L ⁵ , A ^f13 and A ^f14 is 20. ]

^Examples of the alkanediyl group for L ⁵ include the same groups as those exemplified for the alkanediyl group for A ^a41 .
The divalent saturated hydrocarbon group which may have a fluorine atom in A ^f13 is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom and a fluorine atom. Is a divalent alicyclic saturated hydrocarbon group, more preferably a perfluoroalkanediyl group.
Examples of the divalent chain hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene group, perfluoro group. Examples thereof include perfluoroalkanediyl groups such as propanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group and a perfluoroadamantanediyl group.

Examples of the saturated hydrocarbon group of A ^{f14 and} the saturated hydrocarbon group which may have a fluorine atom include the same groups as those exemplified for R ^a42 . Among them, trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, Fluorination of 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group, perfluorooctyl group, etc. Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, Fluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyl dimethyl group, norbornyl group, norbornylmethyl group, perfluoro adamantyl group, a perfluoroalkyl adamantylmethyl group and the like are preferable.

In formula (a4-3), L ⁵ is preferably an ethylene group.
The divalent saturated hydrocarbon group of A ^f13 is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and having a carbon number of A 2-3 divalent chain hydrocarbon group is more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a chain hydrocarbon group having 3 to 10 carbon atoms. And a group containing an alicyclic hydrocarbon group having 3 to 10 carbon atoms are more preferable. Among them, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

Examples of the structural unit represented by the formula (a4-3) include structural units represented by the formula (a4-1′-1) to the formula (a4-1′-11). A structural unit in which a methyl group corresponding to R ^f7 in the structural unit (a4-3) is replaced with a hydrogen atom is also included as the structural unit represented by the formula (a4-3).

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 _{is, - (CH 2) j1 -} , - (CH 2) j2 -O- (CH 2) j3 - or _{- (CH 2) j4 -CO-} O- (CH 2) j5 - represents a.
j1 to j5 each independently represent an integer of 1 to 6.
R ^f22 represents a C 1-10 saturated hydrocarbon group having a fluorine atom. ]

^Examples of the saturated hydrocarbon group of R ^f22 include the same as the saturated hydrocarbon group represented by R ^a42 . R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, more preferably a C 1-10 alkyl group having a fluorine atom. Preferably, a C1-C6 alkyl group having a fluorine atom is more preferable.
In Formula (a4-4), A ^f21 is preferably — (CH ₂ ) _j1 —, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.

As the structural unit represented by the formula (a4-4), for example, in the following structural unit and the structural unit represented by the following formula, a methyl group corresponding to R ^f21 in the structural unit (a4-4) is hydrogen. Structural units in which atoms are replaced are included.
When the resin (A) has the structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on all the structural units of the resin (A). It is more preferably from 10 to 10 mol%.

<Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group contained in the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include structural units represented by the formula (a5-1).
[In the formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. .
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO—. . ]

The alicyclic hydrocarbon group for R ⁵² may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 And an alkyl group such as an ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group for L ⁵⁵ include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent chain saturated hydrocarbon group. .
Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ is replaced by —O— or —CO— are, for example, formula (L1-1) to formula (L1-4). The groups represented may be mentioned. In the formulas below, * and ** represent a bond site, and * represents a bond with an oxygen atom.
In formula (L1-1),
X ^x1 is, * - O-CO- or * -CO-O-a represents (* represents a bond to L ^x1.).
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a C ¹ to C 16 divalent saturated aliphatic hydrocarbon group.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6, and L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by the formula (L1-1) include divalent groups shown below.

Examples of the group represented by the formula (L1-2) include the following divalent groups.

Examples of the group represented by the formula (L1-3) include divalent groups shown below.

Examples of the group represented by the formula (L1-4) include the divalent groups shown below.
L ⁵⁵ is preferably a single bond or a group represented by the formula (L1-1).

Examples of the structural unit (a5-1) include a structural unit shown below and a structural unit in which a methyl group corresponding to R ⁵¹ in the structural unit (a5-1) in the following structural unit is replaced with a hydrogen atom.
When the resin (A) has the structural unit (a5), its content is preferably from 1 to 30 mol%, more preferably from 2 to 20 mol%, based on all the structural units of the resin (A). ˜15 mol% is more preferred.

<Structural unit (II)>
The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter, may be referred to as “structural unit (II).” Specific examples of the structural unit (II) include: Include a structural unit described in JP-A-2016-79235, a structural unit having a sulfonate group or a carboxylate group and an organic cation in a side chain or a structural unit having a sulphonio group and an organic anion in a side chain. Preferably there is.

The structural unit having a sulfonate group or a carboxylate group in its side chain is preferably a structural unit represented by the formula (II-2-A ′).
[In the formula (II-2-A ′),
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O—, —S— or —CO—. Of course, the hydrogen atom contained in the saturated hydrocarbon group may be replaced with a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group.
A ^x1 represents an alkanediyl group having 1 to 8 carbon atoms, and the hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
RA ⁻ represents a sulfonate group or a carboxylate group.
R ^III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
ZA ⁺ represents an organic cation. ]

Examples of the halogen atom represented by R ^III3 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^III3, the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 The same can be mentioned.
Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group. , Hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. Can be mentioned.
Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted with A ^X1 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group and a perfluorotert group. -Butyl group, perfluoropentyl group, perfluorohexyl group and the like.
Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X ^III3 include a linear or branched alkanediyl group and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. However, these may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-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 , A linear alkanediyl group such as dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , A branched alkanediyl group such as pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 , 4-diyl group, Cycloalkanediyl groups such as rooctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group And other divalent polycyclic alicyclic saturated hydrocarbon groups.
Examples of the —CH ₂ — contained in the saturated hydrocarbon group replaced with —O—, —S— or —CO— include divalent groups represented by formula (X1) to formula (X53). Can be mentioned. However, -CH ₂ contained in a saturated hydrocarbon group - is, -O -, - number of carbon atoms before replacing with S- or -CO- is respectively 17 or less. In the following formula, * and ** represent a binding site, and * represents a bond with A ^x1 .

X ³ represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
X ⁴ represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
X ⁵ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
X ⁶ represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁷ represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁸ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

Examples of ZA ⁺ in the formula (II-2-A ′) include the same as the cation Z ⁺ in the salt (I).

The structural unit represented by formula (II-2-A ′) is preferably the structural unit represented by formula (II-2-A).
Wherein ^(II-2-A), R III3, X III3 and ZA ⁺ are the same as defined above.
z2A represents an integer of 0 to 6.
R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R ^III2 and R ^III4 are the same as each other. It may be different or different.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]
^Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same as the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q ^b1 described later. .

The structural unit represented by formula (II-2-A) is preferably the structural unit represented by formula (II-2-A-1).
[In the formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b and ZA ⁺ have the same meanings as described above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
z2A1 represents an integer of 0 to 6.
X ^I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O—, —S— or —CO—. Well, the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]
Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by R ^III5 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include linear or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group.
Examples of the divalent saturated hydrocarbon group represented by X ^I2 include those similar to the divalent saturated hydrocarbon group represented by X ^III3 .

As the structural unit represented by the formula (II-2-A-1), the structural unit represented by the formula (II-2-A-2) is more preferable.
Wherein (II-2-A-2 ), R III3, R III5 and ZA ⁺ are the same as defined above.
mA and nA each independently represent 1 or 2. ]

As the structural unit represented by the formula (II-2-A ′), for example, the following structural unit, a group corresponding to the methyl group of R ^III3 is a hydrogen atom, a halogen atom (for example, a fluorine atom) or a halogen atom. Examples thereof include a structural unit in which an alkyl group having 1 to 6 carbon atoms (for example, a trifluoromethyl group) which may be possessed and a structural unit described in WO 2012/050015 are described. ZA ⁺ represents an organic cation.

The structural unit having a sulfonio group and an organic anion in its side chain is preferably a structural unit represented by the formula (II-1-1).
[In the formula (II-1-1),
A ^II1 represents a single bond or a divalent linking group.
R ^II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
R ^II4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A ⁻ represents an organic anion. ]
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
Examples of the hydrocarbon group represented by R ^II2 and R ^II3 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the halogen atom represented by R ^II4 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^II4 is an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 The same can be mentioned.
Examples of the divalent linking group represented by A ^II1 include divalent saturated hydrocarbon groups having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is It may be replaced by -O-, -S- or -CO-. Specific examples thereof include the same as the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X ^III3 .

As the structural unit containing a cation in the formula (II-1-1), the structural unit represented by the following and the group corresponding to the methyl group of R ^II4 are replaced with a hydrogen atom, a fluorine atom, trifluoromethyl or the like. Examples include structural units.

Examples of the organic anion represented by A ⁻ include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. The organic anion represented by A ⁻ is preferably a sulfonate anion, and the sulfonate anion is more preferably an anion contained in the salt represented by the formula (B1) described below.

A ^- The sulfonyl imide anions represented by, the following may be mentioned.

Examples of the sulfonylmethide anion include the following.

Examples of the carboxylate anion include the following.

Examples of the structural unit represented by the formula (II-1-1) include structural units represented below.
When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol% with respect to the total structural units of the resin (A). It is preferably 2 to 15 mol%, more preferably 3 to 10 mol%.

  The resin (A) may have a structural unit other than the above structural units, and examples of such a structural unit include structural units well known in the art.

  The resin (A) is preferably a resin composed of the structural unit (I) and an acid labile group, a resin composed of the structural unit (I) and the structural unit (a1), a structural unit (I) and a structural unit (s). A resin composed of a structural unit (I), a structural unit (a1) and a structural unit (s), a structural unit (I), a structural unit (a1), a structural unit (s) and a structural unit (a4) And / or a resin containing the structural unit (a5), a resin containing only the structural unit (I), or a resin containing only the structural unit (I) and the structural unit (a4), and more preferably the structural unit ( I), a resin composed of the structural unit (a1) and the structural unit (s), a resin composed of the structural unit (I) and the structural unit (s), or a structural unit (I) and the structural unit (a4) Resin consisting only of unit (a5), structural unit (I) and structural unit (a4 It is a resin comprising only a resin composed of structural units (I) and structural units and (a4) and the structural unit (a1) alone.

The structural unit (a1) is preferably a structural unit (a1-0), a structural unit (a1-0X), a structural unit (a1-1) and a structural unit (a1-2) (preferably a cyclohexyl group and a cyclopentyl group. At least one selected from the group consisting of the structural units having, more preferably the structural unit (a1-0), the structural unit (a1-0X), the structural unit (a1-1) and the structural unit (a1-2). (Preferably, the structural unit having a cyclohexyl group or a cyclopentyl group) is at least two kinds selected from the group consisting of.
The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-A) or the structural unit (a2-1). The structural unit (a3) is preferably a group consisting of a structural unit represented by the formula (a3-1), a structural unit represented by the formula (a3-2) and a structural unit represented by the formula (a3-4). It is at least one selected from.

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that guides these structural units. be able to. The content of each structural unit contained in the resin (A) can be adjusted by the amount of the monomer used for polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably). 15,000 or less).
In the present specification, the weight average molecular weight is a value determined by gel permeation chromatography. Gel permeation chromatography can be measured under the analysis conditions described in the examples.

[Resist composition]
The resist composition of the present invention preferably contains a resin (A) and an acid generator known in the resist field (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition of the present invention may further contain a resin other than the resin (A).
The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (hereinafter sometimes referred to as “quencher (C)”). , A solvent (hereinafter sometimes referred to as “solvent (E)”) is preferably contained.

<Resin other than resin (A)>
The resist composition of the present invention may use a resin other than the resin (A) in combination. The resin other than the resin (A) is a resin that does not contain the structural unit (I), and examples of such a resin include a structural unit having an acid labile group and the structural unit (I) Resin not containing (hereinafter sometimes referred to as "resin (A2)"), resin consisting only of structural unit (a4) and resin consisting of structural unit (a4) and structural unit (a5) (hereinafter structural unit (a4) And the resin consisting of the structural unit (a4) and the structural unit (a5) may be collectively referred to as the resin (X)) and the like.
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, and more preferably 40 mol% or more, based on the total of all structural units of the resin (X). More preferably 45 mol% or more.
Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that induces these structural units. can do. The content of each structural unit contained in the resin (X) can be adjusted by the amount of the monomer used for polymerization.
The weight average molecular weights of the resin (A2) and the resin (X) are each independently preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). is there. The measuring means of the weight average molecular weight of the resin (A2) and the resin (X) is the same as that of the resin (A).
When the resist composition of the present invention contains the resin (A2), the content thereof is usually 1 to 2500 parts by mass (more preferably 10 to 1000 parts by mass) with respect to 100 parts by mass of the resin (A). is there.
When the resist composition contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, relative to 100 parts by mass of the resin (A). , More preferably 1 to 40 parts by mass, particularly preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass.

  The resin (A) content in the resist composition is preferably 80% by mass or more and 99% by mass or less, and more preferably 90 to 99% by mass, based on the solid content of the resist composition. When the resin other than the resin (A) is included, the total content of the resin (A) and the resin other than the resin (A) is 80% by mass or more and 99% by mass or more based on the solid content of the resist composition. It is preferably the following, and more preferably 90 to 99% by mass. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator (B) may be either nonionic or ionic. As the nonionic acid generator, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (for example, disulfone, Ketosulfone, sulfonyldiazomethane) and the like. Representative examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.
Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, and JP-A-63-163452. JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3914407, European Patent 126,712, etc. The compounds capable of generating an acid by the radiation described in 1. can be used. Moreover, you may use the compound manufactured by the well-known method. The acid generator (B) may be used in combination of two or more kinds.

The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).
[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent and is contained in the alicyclic hydrocarbon group; CH ₂ - is, -O -, - S (O ) 2 - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group represented by Q ^b1 and Q ^b2 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group and A perfluorohexyl group etc. are mentioned.
Q ^b1 and Q ^b2 are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably both are a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. It may be a group formed by combining two or more of the groups.
Specifically, methylene group, 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 , Straight chain such as tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group An alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- A branched alkanediyl group such as a 1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group and the like. Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group and adamantane-2,6-diyl group Groups and the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— include, for example, formula (b1-1) to formula (b1-3). And a group represented by any of the above. In the groups represented by the formulas (b1-1) to (b1-3) and the groups represented by the formulas (b1-4) to (b1-11), which are specific examples thereof, * and * * Represents a binding site, and * represents a bond with -Y.

[In the formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, -CH ₂ contained in the hydrocarbon group - may be replaced by -O- or -CO-.
However, the total carbon number of L ^b2 and L ^b3 is 22 or less.
In formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, -CH ₂ contained in the hydrocarbon group - may be replaced by -O- or -CO-.
However, the total carbon number of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, -CH ₂ contained in the hydrocarbon group - may be replaced by -O- or -CO-.
However, the total carbon number of L ^b6 and L ^b7 is 23 or less. ]

Group represented by the formula (b1-1) in the group represented by - formula (b1-3), -CH ₂ contained in a saturated hydrocarbon radicals - if is replaced by -O- or -CO-, the number of carbon atoms before replacing Is the carbon number of the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, -CH ₂ contained in the divalent saturated hydrocarbon group - may be replaced by -O- or -CO-.
The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced by —O— or —CO— is represented by the formula (b1-1) or the formula (b1-3). Are preferred groups.

Examples of the group represented by the formula (b1-1) include groups represented by the formulas (b1-4) to (b1-8).
[In the formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced with —O— or —CO—. Good.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^{b13 to} L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^{b16 to} L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

Examples of the group represented by the formula (b1-3) include groups represented by the formulas (b1-9) to (b1-11).
In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. Good. -CH ₂ contained in the alkylcarbonyloxy group - may be replaced by -O- or -CO-, hydrogen atoms contained in the alkylcarbonyloxy group may be substituted by a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. Good. -CH ₂ contained in the alkylcarbonyloxy group - may be replaced by -O- or -CO-, hydrogen atoms contained in the alkylcarbonyloxy group may be substituted by a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. Good. -CH ₂ contained in the alkylcarbonyloxy group - may be replaced by -O- or -CO-, hydrogen atoms contained in the alkylcarbonyloxy group may be substituted by a hydroxy group.
However, L ^b24, the total number of carbon atoms of L ^b25 and L ^b26 is 21 or less.
In addition, in the group represented by the formula (b1-9) to the group represented by the formula (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, it is replaced. Let the previous carbon number be the carbon number of the saturated hydrocarbon group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group and an adamantylcarbonyloxy group.

Examples of the group represented by the formula (b1-4) include the following.

Examples of the group represented by the formula (b1-5) include groups below.

Examples of the group represented by the formula (b1-6) include the following.

Examples of the group represented by the formula (b1-7) include groups below.

Examples of the group represented by the formula (b1-8) include groups below.

Examples of the group represented by the formula (b1-2) include the following.

Examples of the group represented by the formula (b1-9) include groups below.

Examples of the group represented by the formula (b1-10) include groups below.

Examples of the group represented by the formula (b1-11) include groups below.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formula (Y1) to formula (Y11) and formula (Y36) to formula (Y38).
Is -O - - -CH ₂ contained in the alicyclic hydrocarbon group represented by _{Y, - S (O) 2} - or replaced by -CO-, to the number it may be one, even in two or more Good. Examples of such a group include groups represented by formula (Y12) to formula (Y35) and formula (Y39) to formula (Y41).
The alicyclic hydrocarbon group represented by Y is preferably represented by any one of formula (Y1) to formula (Y20), formula (Y30), formula (Y31), formula (Y39) to formula (Y41). And is more preferably a group represented by formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y30), formula (Y31), formula (Y39) or formula (Y40). And more preferably a group represented by formula (Y11), formula (Y15), formula (Y20), formula (Y30), formula (Y31), formula (Y39) or formula (Y40). .
When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom of the formula (Y28) to the formula (Y35), the formula (Y39), the formula (Y40), or the like, between two oxygen atoms It is preferable that the alkanediyl group of has at least one fluorine atom. Further, of the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

As the substituent of the methyl group represented by Y, a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group,-( ^{_{CH 2) ja -CO-O-}} R b1 group or _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, 3 to 16 carbon atoms It represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms or a group in which these are combined, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— , —SO ₂ — or —CO— may be substituted, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced with a hydroxy group or a fluorine atom. Ja may represent an integer of 0 to 4. Etc. The.
As the substituent of the alicyclic hydrocarbon group represented by Y, a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxy group, an alicyclic group having 3 to 16 carbon atoms Hydrocarbon group, alkoxy group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, glycidyloxy group,-( ^{_{CH 2) ja -CO-O-}} R b1 group or _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, 3 to 16 carbon atoms It represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms or a group in which these are combined, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— , -SO ₂ - may be replaced or -CO-, The hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom, and ja represents an integer of 0 to 4. ) And the like.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group and an adamantyl group.
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group include a tolyl group, a xylyl group, and a cumenyl group. , Mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like, and aromatic having alicyclic hydrocarbon group. Examples of the hydrocarbon group include p-cyclohexylphenyl group and p-adamantylphenyl group.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, and a nonyl group. Group, decyl group, undecyl group, dodecyl group and the like.
Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as hydroxymethyl group and hydroxyethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group and a butyryl group.

Examples of Y include the following.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent. is -CO - - -CH ₂ constituting a hydrogen group or an adamantyl group, - S _{(O) 2} - or -CO- may be replaced with. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by the following.

The anion in the salt represented by the formula (B1) is an anion represented by the formula (B1-A-1) to the formula (B1-A-55) [hereinafter, anion (B1-A depending on the formula number. -1) "and so on. ] Are preferable, Formula (B1-A-1) -Formula (B1-A-4), Formula (B1-A-9), Formula (B1-A-10), Formula (B1-A-24) -Formula (B1-A-33), Formula (B1-A-36) to Formula (B1-A-40), Formula (B1-A-47) to Formula (B1-A-55). Anions are more preferred.

Here, R ^{i2 to} R ⁱ⁷ are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is formed by, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. Group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ^A4 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ^b1 and Q ^b2 have the same meanings as described above.
Specific examples of the anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

Examples of preferable anions in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-34).

  Among them, formula (B1a-1) to formula (B1a-3) and formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22). ) To formula (B1a-30) are preferred.

Examples of Z ⁺ organic cations include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferable, and arylsulfonium cations are more preferable. Specifically, a cation represented by any of the formulas (b2-1) to (b2-4) (hereinafter, may be referred to as “cation (b2-1)” depending on the formula number). Can be mentioned.

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, The hydrogen atom contained in the chain hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom which may be substituted and is contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms or a glycidyloxy group. It may be substituted, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is —O—, —S— or It may be replaced with -CO-.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0-5.
When m2 is 2 or more, a plurality of R ^b7 may be the same or different, and when n2 is 2 or more, a plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is —O—, —S— or It may be replaced with -CO-.
R ^b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and included in the chain hydrocarbon group. The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be an alkoxy group having 1 to 12 carbon atoms or 1 to 12 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded to each other to form a ring including —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring is —O—, —S. -Or-CO- may be substituted.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are the same or different, when p2 is 2 or more, the plurality of R ^b14 are the same or different, and when q2 is 2 or more, the plurality of R ^b15 are the same or different. , When r2 is 2 or more, the plurality of R ^b16 are the same or different, when s2 is 2 or more, the plurality of R ^b17 are the same or different, and when t2 is 2 or more, the plurality of R ^b18 are the same or different. different.
The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.
Examples of the chain hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group and a 2-ethylhexyl group. Can be mentioned.
In particular, the chain hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group or a cyclohexyl group. Examples thereof include cycloalkyl groups such as heptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.
In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.
Examples of the alicyclic hydrocarbon group having a hydrogen atom substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, and a 2-ethyladamantan-2-yl group. , 2-isopropyladamantan-2-yl group, methylnorbornyl group, isobornyl group and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is replaced with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenyl group, naphthyl group and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group, xylyl group). Group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and alicyclic ring having 3 to 18 carbon atoms. Examples thereof include aromatic hydrocarbon groups having a formula hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms Is preferred.
A p-methoxyphenyl group etc. are mentioned as an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group.
Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group and naphthylethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group. , A hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group.
The ring formed by combining R ^b4 and R ^b5 with each other and the sulfur atom to which they are bonded is monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. May be a ring. Examples of this ring include a ring having 3 to 18 carbon atoms, and preferably a ring having 4 to 18 carbon atoms. Moreover, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include the following rings. * Represents a binding site.
The ring formed by R ^b9 and R ^{b10 taken} together may be any of a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring and an unsaturated ring. This ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include thiolane-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, and 1,4-oxathian-4-ium ring.
The ring formed by R ^b11 and R ^{b12 taken} together may be any of a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring and an unsaturated ring. This ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cations (b2-1) to cations (b2-4), the cation (b2-1) is preferable.
Examples of the cation (b2-1) include the following cations.

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

Examples of the cation (b2-4) include the following cations.

  The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B) is preferably the formula (B1a-1) to the formula (B1a-3) and the formula (B1a-7) to the formula (B1a-16), the formula (B1a-18), the formula (B1a-). 19) and a combination of the anion represented by any of the formulas (B1a-22) to (B1a-34) and the cation (b2-1) or the cation (b2-3).

Examples of the acid generator (B) include those represented by formulas (B1-1) to (B1-48), among which those containing an arylsulfonium cation are preferable, and formula (B1-1) ~ Formula (B1-3), Formula (B1-5) to Formula (B1-7), Formula (B1-11) to Formula (B1-14), Formula (B1-20) to Formula (B1-26), Those represented by formula (B1-29) and formula (B1-31) to formula (B1-48) are particularly preferable.

  In the resist composition of the present invention, the content of the acid generator is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A). Is. The resist composition of the present invention may contain one kind of the acid generator (B) alone or may contain plural kinds thereof.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. % Or less. The content of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.
Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate. And the like; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; The solvent (E) may be used alone or in combination of two or more.

<Quencher (C)>
Examples of the quencher (C) include salts that generate an acid having a weaker acidity than the acid generated from the acid generator (B), and basic nitrogen-containing organic compounds. The content of the quencher (C) is preferably about 0.01 to 5% by mass, and more preferably about 0.01 to 3% by mass, based on the solid content of the resist composition.

<Salt that generates an acid having a weaker acidity than the acid generated from the acid generator>
The acidity of a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is represented by an acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3 <pKa, and preferably -1 < It is a salt of pKa <7, more preferably a salt of 0 <pKa <5.
As the salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B), a salt represented by the following formula and a salt represented by the formula (D) described in JP-A-2015-147926. (Hereinafter, it may be referred to as "weak acid inner salt (D)".), And JP2012-229206A, JP2012-6908A, JP2012-72109A, and JP2011-39502A. The salts described in the official gazette and JP 2011-191745 A may be mentioned. The salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is preferably a weak acid intramolecular salt (D).

Examples of the weak acid inner salt (D) include the following salts.

Examples of basic nitrogen-containing organic compounds include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.
As the amine, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, Ludicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyl Didecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylii Dazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridyl amine, 2,2'-dipicolyl amine, bipyridine and the like can be mentioned, preferably aromatic amines such as diisopropyl aniline and the like, more preferably 2,6-diisopropyl. Aniline can be mentioned.
Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl. Examples thereof include ammonium hydroxide, tetra-n-butylammonium salicylate and choline.

<Other ingredients>
The resist composition of the present invention may contain a component (hereinafter sometimes referred to as “other component (F)”) other than the above components, if necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises the resin (A) of the present invention, an acid generator (B), a salt which generates an acid having a weaker acidity than the acid generated from the acid generator, and, if necessary, a resin. It can be prepared by mixing (A2), resin (X), quencher (C), solvent (E) and other component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be selected from 10 to 40 ° C., depending on the type of resin or the like, the solubility of the resin or the like in the solvent (E), or the like. As the mixing time, an appropriate time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing the components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method of manufacturing resist pattern>
The method for producing a resist pattern of the present invention is
(1) a step of applying the resist composition of the present invention onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) exposing the composition layer
(4) A step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

Application of the resist composition onto the substrate can be carried out by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. The substrate may be washed before applying the resist composition, or an antireflection film or the like may be formed on the substrate.
The composition is dried to remove the solvent and form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called prebaking) or using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure during drying under reduced pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.
The obtained composition layer is usually exposed using an exposure device. The exposure machine may be an immersion exposure machine. As the exposure light source, one that emits laser light in the ultraviolet region such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), a solid-state laser light source (YAG or semiconductor laser) Etc.) that emits harmonic laser light in the far-ultraviolet region or vacuum-ultraviolet region by wavelength conversion of laser light from, etc., electron beams, or those that emit ultra-ultraviolet light (EUV), etc. You can In the present specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, it may be exposed by direct drawing without using a mask.
The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) in order to accelerate the deprotection reaction at the acid labile group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.
The composition layer after heating is usually developed using a developing device using a developing solution. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be manufactured by selecting the type of developer as follows.
When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkaline developer may contain a surfactant.
After development, it is preferable to wash the resist pattern with ultrapure water, and then remove the water remaining on the substrate and the pattern.
When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as "organic developer") is used as the developer.
Examples of the organic solvent contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and further preferably substantially only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially butyl acetate and / or 2 More preferably only heptanone.
A surfactant may be contained in the organic developer. Further, the organic developer may contain a small amount of water.
At the time of development, the development may be stopped by substituting with a solvent of a different type from the organic developer.
It is preferable to wash the resist pattern after development with a rinse liquid. The rinse liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

<Use>
The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure. Therefore, it is more suitable as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “part” indicating the content or the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Device: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guard column (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)
In addition, the structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC is model 1100 manufactured by Agilent, and MASS is LC / MSD manufactured by Agilent). In the following examples, the value of this molecular ion peak is indicated by "MASS".

Example 1: Synthesis of compound represented by formula (I-2)
0.65 parts of the compound represented by the formula (I-2-a) and 20 parts of acetonitrile are mixed, stirred at 23 ° C. for 30 minutes, and then the compound represented by the formula (I-2-b) 1.34. Parts were added, the temperature was raised to 50 ° C., and the mixture was stirred at 50 ° C. for 2 hours. 2.03 parts of the compound represented by the formula (I-2-c) was added to the obtained mixture, and the mixture was stirred at 50 ° C. for 2 hours. The obtained mixture was cooled to 23 ° C., 50 parts of chloroform and 20 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, then, separated, and the organic layer was taken out. 20 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and then liquid-separated to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1/1). By fractionating, 1.29 parts of the compound represented by the formula (I-2) was obtained.
MASS: 339.2 [M + H] ⁺

Example 2: Synthesis of compound represented by formula (I-5)
0.65 parts of the compound represented by the formula (I-2-a) and 20 parts of acetonitrile are mixed, stirred at 23 ° C. for 30 minutes, and then the compound represented by the formula (I-2-b) 1.34. Parts were added, the temperature was raised to 50 ° C., and the mixture was stirred at 50 ° C. for 2 hours. 1.01 parts of the compound represented by the formula (I-2-c) was added to the obtained mixture, and the mixture was stirred at 50 ° C. for 2 hours. The obtained mixture was cooled to 23 ° C., 50 parts of chloroform and 20 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, then, separated, and the organic layer was taken out. 20 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, then, liquid separation was performed, and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1/1). By fractionating, 0.58 part of the compound represented by the formula (I-5) was obtained.
MASS: 267.1 [M + H] ⁺

Example 3: Synthesis of compound represented by formula (I-1)
0.65 parts of the compound represented by the formula (I-2-a) and 20 parts of acetonitrile are mixed, stirred at 23 ° C. for 30 minutes, and then the compound represented by the formula (I-2-b) 1.34. Parts were added, the temperature was raised to 50 ° C., and the mixture was stirred at 50 ° C. for 2 hours. 1.61 parts of the compound represented by the formula (I-1-c) was added to the obtained mixture, and the mixture was stirred at 50 ° C. for 2 hours. The obtained mixture was cooled to 23 ° C., 50 parts of chloroform and 20 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, then, separated, and the organic layer was taken out. 20 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and then liquid-separated to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1/1). By fractionating, 1.44 parts of the compound represented by the formula (I-1) was obtained.
MASS: 283.1 [M + H] ⁺

Example 4: Synthesis of compound represented by formula (I-19)
0.65 parts of the compound represented by the formula (I-2-a) and 20 parts of acetonitrile are mixed, stirred at 23 ° C. for 30 minutes, and then the compound represented by the formula (I-2-b) 1.34. Parts were added, the temperature was raised to 50 ° C., and the mixture was stirred at 50 ° C. for 2 hours. 1.82 parts of the compound represented by the formula (I-19-c) was added to the obtained mixture, and the mixture was stirred at 50 ° C for 2 hr. The obtained mixture was cooled to 23 ° C., 50 parts of chloroform and 20 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, then, separated, and the organic layer was taken out. 20 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, then, liquid separation was performed, and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1/1). By fractionating, 1.44 parts of the compound represented by the formula (I-1) was obtained.
MASS: 311.1 [M + H] ⁺

Example 5: Synthesis of compound represented by formula (I-3)
0.65 parts of the compound represented by the formula (I-2-a) and 20 parts of acetonitrile are mixed, stirred at 23 ° C. for 30 minutes, and then the compound represented by the formula (I-2-b) 1.34. Parts were added, the temperature was raised to 50 ° C., and the mixture was stirred at 50 ° C. for 2 hours. 2.45 parts of the compound represented by the formula (I-3-c) was added to the obtained mixture, and the mixture was stirred at 50 ° C. for 2 hours. The obtained mixture was cooled to 23 ° C., 50 parts of chloroform and 20 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, then, separated, and the organic layer was taken out. 20 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, then, liquid separation was performed, and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1/1). By fractionating, 1.12 parts of the compound represented by the formula (I-3) was obtained.
MASS: 395.2 [M + H] ⁺

Example 6: Synthesis of compound represented by formula (I-21)
0.65 parts of the compound represented by the formula (I-2-a) and 20 parts of acetonitrile are mixed, stirred at 23 ° C. for 30 minutes, and then the compound represented by the formula (I-2-b) 1.34. Parts were added, the temperature was raised to 50 ° C., and the mixture was stirred at 50 ° C. for 2 hours. 2.66 parts of the compound represented by the formula (I-21-c) was added to the obtained mixture, and the mixture was stirred at 50 ° C for 2 hr. The obtained mixture was cooled to 23 ° C., 50 parts of chloroform and 20 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, then, separated, and the organic layer was taken out. 20 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, then, liquid separation was performed, and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1/1). By fractionating, 1.01 part of the compound represented by the formula (I-21) was obtained.
MASS: 423.2 [M + H] ⁺

Resin Synthesis Compounds (monomers) used in resin synthesis are shown below.
Hereinafter, these compounds are referred to as “monomer (a1-1-3)” and the like according to the formula numbers.

Example 7 [Synthesis of Resin A1]
As the monomer, acetoxystyrene, the monomer (I-2), the monomer (a1-1-3) and the monomer (a1-2-6) are used, and the molar ratio thereof is [acetoxystyrene: monomer (I-2): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was filtered and recovered to obtain a resin A1 having a weight average molecular weight of about 5.9 × 10 ³ with a yield of 60%. This resin A1 has the following structural units.

Example 8 [Synthesis of Resin A2]
As the monomer, acetoxystyrene, monomer (I-5), monomer (a1-1-3), monomer (a1-2-6) was used, and the molar ratio thereof was [acetoxstyrene: monomer (I-5): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, which was filtered and recovered to obtain a resin A2 having a weight average molecular weight of about 5.6 × 10 ³ with a yield of 53%. This resin A2 has the following structural units.

Example 9 [Synthesis of Resin A3]
As the monomer, acetoxystyrene, monomer (I-1), monomer (a1-1-3) and monomer (a1-2-6) are used, and the molar ratio thereof is [acetoxystyrene: monomer (I-1): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was filtered and recovered to obtain a resin A3 having a weight average molecular weight of about 5.7 × 10 ³ with a yield of 63%. This resin A3 has the following structural units.

Example 10 [Synthesis of Resin A4]
As the monomer, acetoxystyrene, monomer (I-3), monomer (a1-1-3), monomer (a1-2-6) was used, and the molar ratio thereof was [acetoxtyrene: monomer (I-3): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was collected by filtration to obtain a resin A4 having a weight average molecular weight of about 5.5 × 10 ³ with a yield of 58%. This resin A4 has the following structural units.

Example 11 [Synthesis of Resin A5]
As a monomer, acetoxystyrene, a monomer (I-19), a monomer (a1-1-3), a monomer (a1-2-6) was used, and the molar ratio thereof was [acetoxystyrene: monomer (I-19): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was collected by filtration to obtain a resin A5 having a weight average molecular weight of about 5.4 × 10 ³ with a yield of 65%. This resin A5 has the following structural units.

Example 12 [Synthesis of Resin A6]
As the monomer, acetoxystyrene, the monomer (I-21), the monomer (a1-1-3) and the monomer (a1-2-6) were used, and the molar ratio thereof was [acetoxstyrene: monomer (I-21): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was filtered and collected to obtain a resin A6 having a weight average molecular weight of about 5.3 × 10 ³ with a yield of 55%. This resin A6 has the following structural units.

Synthesis Example 1 [Synthesis of Resin AX1]
As the monomer, acetoxystyrene, the monomer (IX-1), the monomer (a1-1-3) and the monomer (a1-2-6) are used, and the molar ratio thereof is [acetoxystyrene: monomer (IX-1): monomer. (A1-1-3): Monomer (a1-2-6)] is mixed in a ratio of 20: 12: 30: 38, and further mixed in this monomer mixture with respect to the total mass of all the monomers. , 1.5 mass times of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was filtered and collected to obtain a resin AX1 having a weight average molecular weight of about 6.0 × 10 ³ with a yield of 48%. This resin AX1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin AX2]
As the monomer, a monomer (a1-4-2), a monomer (IX-1), a monomer (a1-1-3), and a monomer (a1-2-6) are used, and the molar ratio thereof is [monomer (a1-4-2] ): Monomer (IX-1): Monomer (a1-1-3): Monomer (a1-2-6)] are mixed in a ratio of 20: 12: 30: 38, and this monomer mixture is further mixed. Then, 1.5 mass times of methyl isobutyl ketone was mixed with the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of the monomers, and these were added at 73 Heat at ℃ for about 5 hours. Then, a p-toluenesulfonic acid aqueous solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, and the resin was filtered and recovered to obtain a resin AX2 having a weight average molecular weight of about 6.1 × 10 ³ with a yield of 58%. This resin AX2 has the following structural units.

<Preparation of resist composition>
The mixture obtained by mixing and dissolving the components shown in Table 1 was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1 to A6, AX1, AX2: Resin A1 to Resin A6, Resin AX1, Resin AX2
<Acid generator (B)>
B1-43: Salt represented by the formula (B1-43) (synthesized according to the example of JP-A-2016-47815)
<Quencher (C)>
(Salt that generates an acid with weaker acidity than the acid generated from the acid generator)
D1: Synthesized by the method described in JP2011-39502A
D2: (manufactured by Tokyo Chemical Industry Co., Ltd.)
(Nitrogen-containing organic compound)
C1: (Tokyo Chemical Industry Co., Ltd.)
<Solvent>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 150 parts γ-butyrolactone 5 parts

(Evaluation of electron beam exposure of resist composition)
A 6-inch silicon wafer was treated with hexamethyldisilazane on a direct hot plate at 90 ° C. for 60 seconds. This silicon wafer was spin-coated with a resist composition so that the thickness of the composition layer was 0.04 μm. Then, on the direct hot plate, it prebaked for 60 second at the temperature shown in the "PB" column of Table 1, and formed the composition layer. An electron beam drawing machine [“ELS-F125 125 keV” manufactured by Elionix Co., Ltd.] was used for the composition layer formed on the wafer, and the exposure amount was changed stepwise to obtain a contact hole pattern (hole pitch 40 nm / hole. (Diameter 17 nm) was directly drawn.
After exposure, post-exposure bake was performed on the hot plate at the temperature shown in the “PEB” column of Table 1 for 60 seconds, and then paddle development was performed for 60 seconds with a 2.38 mass% tetramethylammonium hydroxide aqueous solution. , A resist pattern was obtained.
In the resist pattern obtained after development, the exposure amount at which the formed hole diameter was 17 nm was defined as the effective sensitivity.

<CD uniformity (CDU) evaluation>
In terms of effective sensitivity, the hole diameter of a pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was determined using a population obtained by measuring the average hole diameter of a pattern formed with a hole diameter of 17 nm on the same wafer at 400 points.
The results are shown in Table 2. Numerical values in the table indicate standard deviation (nm).

Compared with Comparative Compositions 1 and 2, the standard deviations of Compositions 1 to 8 were small, and the CD uniformity (CDU) evaluation was good.

  INDUSTRIAL APPLICABILITY The compound of the present invention and the resist composition using the same can obtain a resist pattern having good CD uniformity (CDU), and are therefore suitable for microfabrication of semiconductors and are extremely useful industrially.

Claims (8)

A compound represented by formula (I).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ³ represents a hydrogen atom, a group represented by the formula (1a) or a group represented by the formula (2a).
R ⁴ represents a group represented by the formula (1a) or a group represented by the formula (2a).
[In Formula (1a), R ^aa1 , R ^aa2, and R ^aa3 each independently represent an alkyl group having 1 to 8 carbon atoms.
naa represents 0 or 1.
* Represents a bond. ]
[In formula (2a), R ^{aa1 '} and R ^aa2' each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R ^{aa3 '} represents an alkyl group having 1 to 8 carbon atoms; -CH ₂ contained in the alkyl group - may be replaced by -O- or -S-.
X ^c represents an oxygen atom or a sulfur atom.
* Represents a bond. ]
R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an alkylcarbonyloxy group having 1 to 6 carbon atoms. Represents a group. ] The compound according to claim 1, wherein R ³ is a group represented by the formula (1a) or a group represented by the formula (2a).   A resin containing a structural unit derived from the compound according to claim 1.   The resin according to claim 3, further comprising a structural unit having an acid labile group other than the structural unit derived from the compound represented by the formula (I).   A resist composition comprising the resin according to claim 3 or 4 and an acid generator. The resist composition according to claim 5, wherein the acid generator contains a salt represented by the formula (B1).
[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent and is contained in the alicyclic hydrocarbon group; CH ₂ - is, -O -, - S (O ) 2 - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]   The resist composition according to claim 5 or 6, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to any one of claims 5 to 7 onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) exposing the composition layer
(4) heating the composition layer after exposure, and (5) developing the composition layer after heating,
A method of manufacturing a resist pattern including: