JP6748493B2 - Resist composition - Google Patents

Description

The present invention relates to a resist composition.

Patent Document 1 describes a resist composition containing a resin composed of the following three structural units and an acid generator represented by the following formula (B1-6).
Patent Document 2 describes a resist composition containing a resin composed of a combination of the following structural units and triphenylsulfonium trifluoromethanesulfonate as an acid generator.

JP, 2007-224008, A JP, 2002-155118, A

The resist pattern formed from the above resist composition was not always satisfactory in terms of CD uniformity (CDU).

The present invention includes the following inventions.
[1] Resin (A1) containing a structural unit represented by the formula (a4-0) and a structural unit having an acid labile group, and an anion having 3 to 18 fluorine atoms and having a cyclic structure A resist composition containing an acid generator (Ba) containing a.
[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]
[2] The resist composition according to [1], wherein L ³ is a perfluoroalkanediyl group having 1 to 2 carbon atoms.
[3] The resist composition according to [1] or [2], wherein R ⁶ is a fluorine atom.
[4] The content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1) [1. ] The resist composition in any one of [3].
[5] The structural unit having an acid labile group is any one of [1] to [4] having a structural unit represented by the formula (a1-1) or a structural unit represented by the formula (a1-2). The resist composition described.
[In Formula (a1-1) and Formula (a1-2),
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 a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
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 combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ]
[6] The resist composition according to any one of [1] to [5], wherein the anion of the acid generator (Ba) is an anion having a partial structure represented by formula (IB).
[In the formula (IB),
A ¹ represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
R ³ represents a hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The contained hydrogen atom may be substituted with a hydroxy group. A ¹ and R ³ may be bonded to each other to form a ring which may have a hetero atom together with the carbon atom to which they are bonded.
X ^a and X ^b each independently represent an oxygen atom or a sulfur atom.
X ² represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms, which may have a fluorine atom.
* Is a bond. ]
[7] The resist composition according to any one of [1] to [6], further including a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[8] The resist composition according to any one of [1] to [7], further including a resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group. Resist composition.
[9] (1) A step of applying the resist composition according to any one of [1] to [8] onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) a step of exposing the composition layer,
A method for producing a resist pattern, which comprises (4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

According to the resist composition of the present invention, a resist pattern having good CD uniformity (CDU) can be manufactured.

In the present specification, “(meth)acrylate” means “at least one of acrylate and methacrylate”. The expressions such as “(meth)acrylic acid” and “(meth)acryloyl” have the same meaning.
Further, unless otherwise specified, a group which can be linear or branched, such as an “aliphatic hydrocarbon group”, includes both of them. The "aromatic hydrocarbon group" also includes a group in which a hydrocarbon group is bonded to an aromatic ring. 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.

[Resist composition]
The resist composition of the present invention contains a resin (A1) and an acid generator (Ba).
The resist composition may further contain a resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group. Further, an acid generator other than the acid generator (Ba) may be contained.
Furthermore, the resist composition contains a quencher such as a salt (hereinafter sometimes referred to as “quencher (C)”) that generates an acid having a weaker acidity than an acid generated from the acid generator and/or a solvent (hereinafter “quencher (C)”). It may contain a solvent (E)” in some cases.

<Resin (A1)>
The resin (A1) includes a structural unit represented by the formula (a4-0) (hereinafter sometimes referred to as “structural unit (a4-0)”) and a structural unit having an acid labile group (hereinafter referred to as “structural unit”). (A1)").
The “acid-labile group” of the structural unit is a group having a leaving group, which has a hydrophilic group (for example, a hydroxy group or a carboxyl group) when the leaving group is released by contact with an acid. It means a group converted into a structural unit.
The resin (A1) further comprises a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) and/or another structural unit (hereinafter referred to as “structural unit (t)”). May be included).

<Structural unit (a4-0)>
The resin (A1) has a structural unit (a4-0).
[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

As the aliphatic saturated hydrocarbon group for L ⁴ , a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, or a linear alkanediyl group. Having an alkyl group (among others, a methyl group or an ethyl group) side chain, an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, 2 Examples include branched alkanediyl groups such as -methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.

Examples of the perfluoroalkanediyl group for L ³ include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene 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, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2 -Diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group for L ³ include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group and a perfluoroadamantanediyl group.

L ⁴ is preferably a single bond, a methylene group or an ethylene group, and more preferably a methylene group or an ethylene group.
L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms, and further preferably a perfluoroalkanediyl group having 1 to 2 carbon atoms. And particularly preferably a difluoromethylene group.
R ⁶ is preferably a fluorine atom.

Examples of the structural unit (a4-0) include the structural units shown below.

The content of the structural unit (a4-0) is, based on the total of all structural units of the resin (A1), 0.5 mol% or more and 50.0 mol% or less, and preferably 0.5 mol% or more. 40.0 mol% or less, more preferably 0.5 mol% or more and 9.5 mol% or less, still more preferably 0.5 mol% or more and 7.5 mol% or less, and even more preferably 0. The amount is 0.5 mol% or more and 5.0 mol% or less, more preferably 0.5 mol% or more and 4.5 mol% or less, and particularly preferably 1 mol% or more and 4 mol% or less.

The monomer (a4-0) for deriving the structural unit (a4-0) is easily available from the market.

<Structural unit (a1)>
The resin (A1) contains the structural unit (a1) in addition to the structural unit (a4-0).
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
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.
In the resin (A1), the acid labile group contained in the structural unit (a1) is preferably a group represented by the following formula (1) and/or a group represented by the following formula (2).
[In the formula (1), R ^{a1 to} 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, or , R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and R ^a3 is an alkyl group having 1 to 8 carbon atoms and an alicyclic carbon group having 3 to 20 carbon atoms. It represents a hydrogen group or a group combining these.
na represents 0 or 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 ^{a1 ′} represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^{a2 ′} and R ^{a3 ′} are bonded to each other and the carbon atom to which they are bonded and X are 3 to 3 carbon atoms. 20 divalent heterocyclic groups are formed, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocyclic group may be replaced with —O— or —S—.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

^Examples of the alkyl group of R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group and an n-octyl group.
The alicyclic hydrocarbon group of R ^{a1 to} 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, the following groups (* represents a bond), and the like. The alicyclic hydrocarbon group of R ^{a1 to} 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 a methylcyclohexyl group, a dimethylcyclohexyl group and a methylnorbornyl group.

In the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group, -C(R ^a1 )(R ^a2 )(R ^a3 ) includes the groups below, and * represents -O-. Represents a bond with. The carbon number of the divalent hydrocarbon group is preferably 3-12.

The group represented by the formula (1) is a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group. .), a 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to each other, and together with the carbon atom to which they are bonded, an adamantyl group is formed to form R ^a3. Is an alkyl group) and a 1-(adamantan-1-yl)-1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group) ) And the like.

Examples of the hydrocarbon group of R ^{a1 ′ to} 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 are the same as those mentioned above.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, xylyl group, cumyl group, mesityl group, biphenyl group, phenanthryl group. And aryl groups such as 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.
^{Examples of the} divalent heterocyclic group formed by R ^{a2 ′} and R ^{a3 ′} bonded to each other and the carbon atom to which they are bonded and X include the following groups. * Represents a bond.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

Among the (meth)acrylic monomers having an acid labile group, a (meth)acrylic monomer having an alicyclic hydrocarbon group having 5 to 20 carbon atoms is preferable. From the resist composition containing the resin (A1) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group, a resist pattern with further improved resolution can be formed.

Preferred examples of the structural unit derived from the (meth)acrylic monomer having a group represented by the formula (1) include a structural unit represented by the formula (a1-0) and a structural unit represented by the formula (a1-1). And a structural unit represented by the formula (a1-2). These may be used alone or in combination of two or more. In the present specification, the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are respectively represented by the structural unit (a1 -0), a structural unit (a1-1) and a structural unit (a1-2) may be referred to, and a monomer that induces the structural unit (a1-0), a monomer that induces the structural unit (a1-1), and a structural unit The monomer that induces (a1-2) may be referred to as a monomer (a1-0), a monomer (a1-1), and a monomer (a1-2), respectively.
[In the formula (a1-0),
L ^a01 represents an oxygen atom or *—O—(CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond with a carbonyl group.
R ^a01 represents 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. ]
[In Formula (a1-1) and Formula (a1-2),
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 a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
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 the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ]

L ^a02 is preferably an oxygen atom or *—O—(CH ₂ ) _k01 —CO—O—, and more preferably an oxygen atom. k01 is preferably an integer of 1 to 4, and more preferably 1.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , the alicyclic hydrocarbon group, and a group in which these are combined include the same groups as those described for R ^{a1 to} R ^a3 of the formula (1).
The alkyl group of R ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.
The carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably 3 or more and 8 or less, and more preferably 3 or more and 6 or less.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in which these alkyl groups and the alicyclic hydrocarbon group are combined. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
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.

L ^a1 and L ^a2 are independently of each other, preferably —O— or *—O—(CH ₂ ) _k1′ —CO—O—, and more preferably —O—. k1′ is an integer of 1 to 4, preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
^Examples of the alkyl group of R ^a6 and R ^a7 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, Examples thereof include n-heptyl group, 2-ethylhexyl group and n-octyl group.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group. Examples thereof include a cycloalkyl group such as a group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1-(adamantan-1-yl)alkane-1-yl group, a norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
Examples of the group formed by combining the alkyl group of R ^a6 and R ^a7 and the alicyclic hydrocarbon group include an aralkyl group, and a benzyl group, a phenethyl group and the like.
The carbon number of the alkyl group of R ^a6 and R ^a7 is preferably 6 or less.
The number of carbon atoms of the alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably 3 or more and 8 or less, and more preferably 3 or more and 6 or less.
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.

As the structural unit (a1-0), structural units represented by formulas (a1-0-1) to (a1-1-12) and a methyl group corresponding to R ^a01 in these structural units are hydrogen atoms. The substituted structural unit is mentioned, Preferably it is a structural unit represented by either formula (a1-0-1)-formula (a1-1-10).

Examples of the monomer (a1-1) include the monomers described in JP2010-204646A. Among them, the monomers represented by the following formulas (a1-1-1) to (a1-1-8) are preferable, and the monomers represented by the formulas (a1-1-1) to (a1-1-4) are preferred. Is more preferable.

Examples of the monomer (a1-2) include monomers represented by the following formula (a1-2-1) to formula (a1-2-12), and formula (a1-2-3) and formula (a1-2). -4), monomers represented by formula (a1-2-9) and formula (a1-2-10) are preferable, and monomers represented by formula (a1-2-3) and formula (a1-2-9) are represented. Monomers are more preferred.

When the resin (A1) 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 (A1). It is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 85 mol% based on the total of the units.

Further, the structural unit (a1) having a group represented by the formula (1) also includes a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Further, the monomer that induces the structural unit (a1-3) may be referred to as a monomer (a1-3).
[In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group which may have a hydroxy group and has 1 to 3 carbon atoms, a carboxy group, a cyano group, a hydrogen atom or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, and the aliphatic hydrocarbon group and The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—. Alternatively, it may be replaced with -CO-.
R ^a10 , R ^a11, and R ^a12 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 formed by combining these. ^{or, R a12} are each independently an alkyl group having 1 to 8 carbon atoms, a group formed by combining the alicyclic hydrocarbon group or those having 3 to 20 carbon ^{atoms, R a10} and ^{R a11} Combine with each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the carbon atom to which they are bonded. ]

Here, examples of —COOR ^a13 include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the aliphatic hydrocarbon group which may have a hydroxy group for R ^a9 include a methyl group, an ethyl group, an n-propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms of R ^a13 include a methyl group, an ethyl group and an n-propyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms of R ^a13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantyl methyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3-. Examples thereof include an yl group and a 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group of R ^{a10 to} R ^a12 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, Examples thereof include n-heptyl group, 2-ethylhexyl group and n-octyl group.
The alicyclic hydrocarbon group of R ^{a10 to} R ^a12 may be monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, Examples thereof include cycloalkyl groups such as cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1-(adamantan-1-yl)alkane-1-yl group, a norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
In the case where R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group together with the carbon atom to which they are bonded, -C(R ^a10 )(R ^a11 )(R ^a12 ) is as follows. Groups are preferred.

Specific examples of the monomer (a1-3) include 5-tert-butyl 5-norbornene-2-carboxylic acid, 1-cyclohexyl-1-methylethyl 5-norbornene-2-carboxylic acid, and 5-norbornene-2-carboxylic acid. Acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1-(4 -Methylcyclohexyl)-1-methylethyl, 5-norbornene-2-carboxylic acid 1-(4-hydroxycyclohexyl)-1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1-(4-oxo Cyclohexyl)ethyl and 1-(1-adamantyl)-1-methylethyl 5-norbornene-2-carboxylic acid.

Since the resin (A1) containing the structural unit (a1-3) contains a sterically bulky structural unit, a resist composition containing such a resin (A1) can be used to form a resist with higher resolution. You can get the pattern. Further, since a rigid norbornane ring is introduced into the main chain, the obtained resist pattern tends to have excellent dry etching resistance.

When the resin (A1) contains the structural unit (a1-3), its content is preferably 10 to 95 mol% with respect to the total of all structural units of the resin (A1), and 15 to 90 mol%. %, more preferably 20 to 85 mol %.

As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). Can be mentioned.
[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 acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or Represents a methacryloyloxy group.
la represents the integer of 0-4. When la is 2 or more, a plurality of R ^a33 may be the same or different from each other.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon ^atoms, or ^{R a36} represents a hydrocarbon group having 1 to 20 carbon atoms, ^{or, R a34} is hydrogen represents an atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a35 and R ^a36 are bonded together to form a divalent hydrocarbon group having 2 to 20 carbon atoms with each other, the carbonization of the hydrocarbon group and the divalent -CH ₂ contained in the hydrogen radical - may be replaced by -O- or -S-. ]

^Examples of the alkyl group of R ^a32 and R ^a33 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-pentyl group and an n-hexyl group, and preferably a carbon number of 1 to 4 And an alkyl group are more preferable, a methyl group or an ethyl group is more preferable, and a methyl group is more preferable.
Examples of the halogen atom of R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1,1,2,2-tetrafluoro Ethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluoro Butyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group, n-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. Especially, a C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
Examples of the hydrocarbon group R ^a34 and ^{R a35,} include the same groups as ^{R a1 'and R a2'} of formula (2).
R ^a36 includes 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, and a group formed by combining these. Can be 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 a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group for 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 aliphatic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms.
The alkyl group and the alicyclic hydrocarbon group for R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group for R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

Examples of the monomer that leads to the structural unit (a1-4) include the monomers described in JP2010-204646A. Especially, the monomer represented by Formula (a1-4-1)-Formula (a1-4-8) is preferable, and the monomer represented by Formula (a1-4-1)-Formula (a1-4-5) is More preferable.

When the resin (A1) has the structural unit (a1-4), its content is preferably 10 to 95 mol% with respect to the total of all structural units of the resin (A1), and preferably 15 to 90. It is more preferably mol%, and further preferably 20 to 85 mol%.

The structural unit having an acid labile group also includes a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”).
[In formula (a1-5),
^Ra8 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 -, h3 represents an integer of 1 to 4, and * represents a bond with L ⁵¹ .
L ^<51> , L ^<52> , L ^<53> and L ^<54 > independently represent -O- or -S-.
s1 represents an integer of 1 to 3.
s1' represents the integer of 0-3. ]

In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably —O—.
It is preferable that one of L ⁵² and L ⁵³ is -O-, and the other is -S-.
As s1, 1 is preferable.
As s1′, an integer of 0 to 2 is preferable.
Z ^a1 is preferably a single bond or *—CH ₂ —CO—O—.

Examples of the monomer leading to the structural unit (a1-5) include the monomers described in JP 2010-61117A. Among them, the monomers represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and the monomers represented by formula (a1-5-1) and formula (a1-5-2) are More preferable.

When the resin (A1) has the structural unit (a1-5), its content is preferably 1 to 50 mol% with respect to the total of all structural units of the resin (A1), and 3 to 45. It is more preferably mol%, and further preferably 5 to 40 mol%.

As the structural unit (a1) having an acid labile group in the resin (A1), the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2) and the structural unit (a1-5). At least one selected from the group consisting of), more preferably at least two or more, and a combination of structural unit (a1-1) and structural unit (a1-2), structural unit (a1-1) and structural unit ( a1-5), structural unit (a1-1) and structural unit (a1-0), structural unit (a1-2) and structural unit (a1-0), structural unit (a1-5) And a combination of structural units (a1-0), a structural unit (a1-0), a combination of structural units (a1-1) and a structural unit (a1-2), a structural unit (a1-0), a structural unit (a1- 1) and the structural unit (a1-5) are more preferable, and the combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit (a1-5) Combinations are even more preferred.

<Structural unit having no acid labile group>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). Examples of the monomer (s) include monomers that do not have an acid labile group known in the resist field. A preferred structural unit is a structural unit having a hydroxy group or a lactone ring and having no acid labile group. A structure 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 From a resist composition containing a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”), a resist pattern having improved resolution and adhesion to a substrate can be formed.

<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 (ultra-ultraviolet light) is used as an exposure light source, it is used as a structural unit (a2). 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 the structural unit (a2) having an alcoholic hydroxy group, and more preferably the structural unit (a2-1). As the structural unit (a2), one type may be included alone, or two or more types may be included.

Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).
[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a31 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 acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
ma represents the integer of 0-4. When ma is an integer greater than or equal to 2, some R ^<a31 > may be mutually same or different. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom of R ^a30 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1 , 1,2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group Group, an n-perfluorohexyl group and the like.
As R ^a30 , a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is preferable, a hydrogen atom, a methyl group or an ethyl group is more preferable, and a hydrogen atom or a methyl group is further preferable.
^Examples of the alkoxy group of R ^a31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Especially, a C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the acyl group of R ^a31 include an acetyl group, a propionyl group and a butyryl group.
^Examples of the acyloxy group of R ^a31 include an acetyloxy group, a propionyloxy group and a butyryloxy group.
As ma, 0, 1 or 2 is preferable, 0 or 1 is more preferable, and 0 is further preferable.

Examples of the monomer that derives the structural unit (a2-0) include the monomers described in JP 2010-204634 A.
Among them, the structural unit (a2-0) is represented by the formula (a2-0-1), the formula (a2-0-2), the formula (a2-0-3) and the formula (a2-0-4). Embedded image is preferable, and the structural unit represented by formula (a2-0-1) or formula (a2-0-2) is more preferable.

The resin (A1) containing the structural unit (a2-0) undergoes a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that induces the structural unit (a2-0) is protected by a protecting group, and then deprotected. It can be produced by processing. However, it is necessary to perform the deprotection treatment so that the acid labile group contained in the structural unit (a1) is not significantly impaired. An acetyl group etc. are mentioned as such a protective group.

When the resin (A1) has a structural unit (a2-0) having a phenolic hydroxy group, its content is 5 to 95 mol% based on the total of all structural units of the resin (A1). Is preferable, 10-80 mol% is more preferable, and 15-80 mol% is further preferable.

Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).
[In the 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 an integer of 0 to 10. ]

In formula (a2-1), L ^a3 is preferably —O—, —O—(CH ₂ ) _f1 —CO—O— (where f1 is an 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 monomer that induces the structural unit (a2-1) include the monomers described in JP2010-204646A. The monomer represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and the monomer represented by any of the formulas (a2-1-1) to (a2-1-4) is represented. Is more preferable, and the monomer represented by formula (a2-1-1) or formula (a2-1-3) is still more preferable.

When the resin (A1) contains the structural unit (a2-1), its content is usually 1 to 45 mol%, preferably 1 to 40 mol, based on the total of all structural units of the resin (A1). %, more preferably 1 to 35 mol %, further preferably 2 to 20 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. The lactone ring is preferably a γ-butyrolactone ring or a bridged ring containing a γ-butyrolactone ring structure.

The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These may be contained alone or in combination of two or more.
[In the formula (a3-1),
L ^a4 represents -O- or _{* -O- (CH 2) k3 -CO} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond with the carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents the integer of 0-5. When p1 is 2 or more, a plurality of R ^a21 may be the same or different.
In formula (a3-2),
L ^a5 represents a group represented by —O— or *—O—(CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with the carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, a plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— or *—O—(CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with the carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, a plurality of R ^a23 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group such as R ^a21 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group.

In formulas (a3-1) to (a3-3), L ^{a4 to} L ^a6 are each independently preferably —O— or *—O—(CH ₂ ) in which k3 is an integer of 1 to 4. a _k3 -CO-O-group represented by, more preferably -O- _{and, * - O-CH 2 -CO} -O- and, still 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 an integer of preferably 0 to 2 and more preferably 0 or 1.

Examples of the monomer that leads to the structural unit (a3) include the monomer described in JP2010-204646A, the monomer described in JP2000-122294A, and the monomer described in JP2012-41274A. Can be mentioned. As the structural unit (a3), formula (a3-1-1) to formula (a3-1-4), formula (a3-2-1) to formula (a3-2-4), formula (a3-3-). 1) to the structural unit represented by any of the formulas (a3-3-4) are preferable, and the formula (a3-1-1), the formula (a3-1-2) and the formula (a3-2-3) to The structural unit represented by any of the formulas (a3-2-4) is more preferable, and the structural unit represented by the formula (a3-1-1) or the formula (a3-2-3) is further preferable.

When the resin (A1) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol% with respect to the total of all structural units of the resin (A1). And more preferably 10 to 60 mol %.
The content of the structural unit (a3-1), the structural unit (a3-2), and the structural unit (a3-3) is, independently of each other, 5 to the total of all structural units of the resin (A1). It is preferably 60 mol%, more preferably 5 to 50 mol%, and further preferably 10 to 50 mol%.

<Other structural units (t)>
As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit which may have a fluorine atom (hereinafter, referred to as “structural unit (a4)” depending on the case. (Excluding (a4-0)) and a structural unit having a non-eliminating hydrocarbon group (hereinafter sometimes referred to as “structural unit (a5)”) and the like.

Examples of the structural unit (a4) include structural units represented by the formula (a4-1).
[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—. Good.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). ]
[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have 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.
Of the two bonds represented by *, the * on the right side is a bond with -O-CO- ^Ra42 . ]

^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
The chain and cyclic aliphatic hydrocarbon groups may have a carbon-carbon unsaturated bond, but chain and cyclic aliphatic saturated hydrocarbon groups and combinations thereof are preferable. The aliphatic saturated hydrocarbon group includes a linear or branched alkyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a fat formed by combining an alkyl group and an alicyclic hydrocarbon group. Group hydrocarbon groups and the like can be mentioned.

Examples of the chain type aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and an n-decyl group. Group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. Examples of the cyclic aliphatic hydrocarbon group include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and other cycloalkyl groups; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* is a bond And a polycyclic alicyclic hydrocarbon group such as.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group and a fluorenyl group.

The hydrocarbon group for R ^a42 is preferably a chain or cyclic aliphatic hydrocarbon group or a group formed by combining these, and may have a carbon-carbon unsaturated bond, And cyclic aliphatic saturated hydrocarbon groups and groups formed by combining these are more preferable.
^Examples of the substituent of R ^a42 include a halogen atom or 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, preferably a fluorine atom.
[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having at least one halogen atom and having 1 to 17 carbon atoms.
* Represents a bond. ]

^As the aliphatic hydrocarbon group for A ^a45, the same groups as those exemplified for R ^a42 can be mentioned.

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an aliphatic hydrocarbon group having an alkyl group having a halogen atom and/or a group represented by the formula (a-g3). ..
In R ^a42 , the aliphatic hydrocarbon group having a halogen atom is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and 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 an aliphatic hydrocarbon group having a group represented by formula (a-g3), the aliphatic hydrocarbon including the carbon number contained in the group represented by formula (a-g3) The total carbon number of the group 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.

The aliphatic hydrocarbon group having a group represented by formula (a-g3) is more preferably a group represented by formula (a-g2).
[In the formula (a-g2),
A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
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. ]

The aliphatic hydrocarbon group for A ^a46 preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
The aliphatic hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and further preferably a cyclohexyl group or an adamantyl group.

The preferable structure represented by *-A ^a46 -X ^a44 -A ^a47 is the following structure.

^Examples of the alkanediyl group of A ^a41 include 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 of 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 aliphatic hydrocarbon group of A ^{a42 to} A ^a44 in the group (a-g1) may have a carbon-carbon unsaturated bond, but an aliphatic saturated hydrocarbon group is preferable. As the aliphatic saturated hydrocarbon group, an alkyl group (the alkyl group may be linear or branched) and an alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group are combined. And an aliphatic hydrocarbon group formed by the above. 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 aliphatic hydrocarbon group of A ^{a42 to} A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
As s, 0 is preferable.

^Examples of the group (a-g1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with -O-CO-Ra ⁴² .

As the structural unit represented by the formula (a4-1), structural units represented by the formula (a4-2) and the formula (a4-3) are preferable.
[In the formula (a4-2),
R ^f1 represents a hydrogen atom or a methyl group.
A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.
R ^f2 represents a hydrocarbon group having a fluorine atom and having 1 to 10 carbon atoms. ]

The alkanediyl group of A ^f1 includes 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 pentane-1,5-diyl group. , A linear alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 Examples thereof include branched alkanediyl groups such as -diyl group, 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a group formed by a chain structure, a ring structure and a combination thereof. The aliphatic hydrocarbon group is preferably an alkyl group or an alicyclic hydrocarbon group.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 And an ethylhexyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Can be mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1-(adamantan-1-yl)alkane-1-yl group, a norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1 , 1,2,2-Tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2,2,2- Tetrafluoroethyl group, 1-(trifluoromethyl)-2,2,2-trifluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3 ,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2- Trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3 , 4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, 2-(perfluorobutyl)ethyl group, 1 , 1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoro Examples thereof include fluorinated alkyl groups such as hexyl group, perfluoropentylmethyl group and perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

As A ^f1 in the formula (a4-2), an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
As R ^f1 , a fluorinated alkyl group having 1 to 6 carbon atoms is preferable.

[In the formula (a4-3),
R ^f11 represents a hydrogen atom or a methyl group.
A ^f11 represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group which may have a fluorine atom and has 1 to 17 carbon atoms.
However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

^Examples of the alkanediyl group of A ^f11 include the same groups as the alkanediyl group of A ^f1 .
The aliphatic hydrocarbon group for A ^f13 includes a chain and cyclic aliphatic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. To be
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; a difluoromethylene group, a perfluoroethylene group. And perfluoroalkanediyl groups such as a group, a perfluoropropanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either a monocyclic group or a polycyclic group. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group and a perfluoroadamantanediyl group.

The aliphatic hydrocarbon group for A ^f14 includes any of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Examples of the chain aliphatic hydrocarbon group which may have a fluorine atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1 , 2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, Examples thereof include a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group and a perfluorocyclohexyl group. Examples of the group containing a polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group and the like.

In the formula ^{(a4-3), A f11} is preferably an ethylene group.
The aliphatic hydrocarbon group for A ^f13 is preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and more preferably an aliphatic hydrocarbon group having 2 to 3 carbon atoms.
As the aliphatic hydrocarbon group of A ^f14, an aliphatic hydrocarbon group having 3 to 12 carbon atoms is preferable, and an aliphatic hydrocarbon group having 3 to 10 carbon atoms is 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 (a4-2) include structural units represented by the formula (a4-1-1) to the formula (a4-1-22).

Examples of the structural unit represented by the formula (a4-3) include structural units represented by the formulas (a4-1'-1) to (a4-1'-22).

The structural unit (a4) also includes a structural unit represented by the formula (a4-4).
[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 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same as the hydrocarbon group of R ^f2 in the formula (a4-2). 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, and a C 1-10 alkyl having a fluorine atom. A group is more preferable, and a C 1-6 alkyl group having a fluorine atom is further preferable.

In formula ^(A4-4), as the _{^{A f21, - (CH 2)}} j1 - , more preferably an ethylene group or a methylene group, more preferably a methylene group.

Examples of the structural unit represented by the formula (a4-4) include the following structural units.

When the resin (A1) has the structural unit (a4), its content is preferably 1 to 20 mol %, and 2 to 15 mol% based on the total of all structural units of the resin (A1). Is more preferable, and 3 to 10 mol% is further preferable.

Examples of the non-eliminating hydrocarbon group contained in the structural unit (a5) include linear, branched or cyclic hydrocarbon groups. Among them, the structural unit (a5) is preferably a group containing 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 a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁵⁵ is not substituted with the 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 the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

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.
The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include alkyl groups such as octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and 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 aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. To be
Examples of the divalent saturated aliphatic 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 the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group include groups represented by formula (L1-1) to formula (L1-4). In the following formula, * represents a bond with an oxygen atom.
[In the formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
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 divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
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 to} L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 each independently 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, and 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, and more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, and 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 the following divalent groups.

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

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

Examples of the group represented by the formula (L1-4) include the following divalent groups.

L ⁵⁵ is preferably a single bond or a group represented by the formula (L1-1).

Examples of the structural unit (a5-1) include the followings.
In formulas (a5-1-1) to (a5-1-18), a structural unit in which a methyl group corresponding to R ⁵¹ is replaced with a hydrogen atom may be mentioned as a specific example of the structural unit (a5-1). it can.

When the resin (A1) has the structural unit (a5), its content is preferably 1 to 30 mol% and preferably 2 to 20 mol% based on the total of all structural units of the resin (A1). Is more preferable, and 3 to 15 mol% is further preferable.

The resin (A1) is preferably a resin composed of a structural unit (a4-0), a structural unit (a1) and a structural unit (s), that is, a monomer (a4-0), a monomer (a1) and a monomer (s). It is a resin that is a copolymer with.
The structural unit (a1) is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), and more preferably the structure It is a unit (a1-1), and more preferably contains both the structural unit (a1-1) and the structural unit (a1-2).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1). The structural unit (a3) is preferably at least one of the structural unit represented by the formula (a3-1) and the structural unit represented by the formula (a3-2).

The resin (A1) contains the structural unit derived from the monomer having an adamantyl group (in particular, the structural unit (a1-1)) in an amount of 15 mol% or more based on the content of the structural unit (a1). preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A1) 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 of the resin (A1) can be adjusted by changing the amount of the monomer used for polymerization.
The weight average molecular weight of the resin (A1) 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 obtained by gel permeation chromatography. Gel permeation chromatography can be measured under the analysis conditions described in the examples.

<Resin (A2)>
As the resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group, a resin containing the structural unit (a4-0) or the structural unit (a4) is preferable. In the resin (A2), the content of the structural unit (a4-0) or the structural unit (a4) is preferably 40 mol% or more, and 45 mol% with respect to the total of all structural units of the resin (A2). % Or more, and more preferably 50 mol% or more.
Examples of the structural unit that the resin (A2) may further have include structural units (a2), structural units (a3), structural units (a5), and structural units derived from other known monomers.
The weight average molecular weight of the resin (A2) is preferably 5,000 or more (more preferably 6,000 or more) and 80,000 or less (more preferably 60,000 or less).
When the resist composition of the present invention contains the resin (A2), 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 (A1). %, more preferably 2 to 40 parts by mass, still more preferably 2 to 30 parts by mass, and particularly preferably 2 to 10 parts by mass.

The total content of the resin (A1) and the resin (A2) is preferably 80% by mass or more and 99% by mass or less based on the solid content of the resist composition. 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 (Ba)>
The acid generator generates an acid upon exposure to light, and the generated acid acts as a catalyst to eliminate a group that is eliminated by the acid of the resin (A1).
The acid generator (Ba) is an acid generator having an anion having 3 to 18 fluorine atoms and having a cyclic structure. The fluorine atom may be contained in any of the cyclic structure and/or the part other than the cyclic structure.

Examples of the anion in the acid generator (Ba) include anions having a partial structure represented by the formula (IB).
[In the formula (IB),
A ¹ represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
R ³ represents a hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The contained hydrogen atom may be substituted with a hydroxy group. A ¹ and R ³ may be bonded to each other to form a ring which may have a hetero atom together with the carbon atom to which they are bonded.
X ^a and X ^b each independently represent an oxygen atom or a sulfur atom.
X ² represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms, which may have a fluorine atom.
* Is a bond. ]

Examples of the C 1-12 divalent hydrocarbon group of A ¹ include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, an aromatic hydrocarbon group and the like. Also, a combination of two or more of these groups may be used.
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 A linear alkanediyl group such as;
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 Group;
Phenylene group, naphthylene group, anthrylene group, p-methylphenylene group, p-tert-butylphenylene group, p-adamantylphenylene group, tolyl group, xylylene group, cumenylene group, mesitylene group, biphenylene group, phenanthrylene group, 2,6 Examples thereof include aromatic hydrocarbon groups such as a diethylphenylene group and a 2-methyl-6-ethylphenylene group.
The divalent alicyclic hydrocarbon group may be a group obtained by removing any one hydrogen atom from the monovalent alicyclic hydrocarbon group shown in the present specification.

Examples of the hydrocarbon group having 1 to 18 carbon atoms in R ³ include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
As the alkyl group, 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, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group. , Nonyl group, decyl group, undecyl group and dodecyl group.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and as the monocyclic alicyclic hydrocarbon group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, Examples thereof include cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1-(adamantan-1-yl)alkane-1-yl group, a norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.
Examples of the group formed by combining include an aralkyl group, and examples of the aralkyl group include a benzyl group and a phenethyl group.

As the ring in which A ¹ and R ³ are bonded to each other and may have a hetero atom together with the carbon atom to which they are bonded, a cyclopropyl ring, a cyclobutyl ring, a cyclopentyl ring, a cyclohexyl ring, a cycloheptyl ring, a cyclooctyl ring, Examples thereof include a cyclodecyl ring, a decahydronaphthyl ring, an adamantane ring, a norbornane ring, a cyclohexanone ring, an adamantanenone ring, a butyrolactone ring, an adamantane lactone ring and a norbornane lactone ring.
The ring formed by A ¹ and R ³ is preferably an adamantane ring.

The divalent saturated hydrocarbon group having 1 to 12 carbon atoms in X ² is a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. And a combination of two or more of these groups may be used.
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 a dodecane-1,12-diyl group;
An alkyl group (especially an alkyl group having 1 to 4 carbon atoms, 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, etc.) in addition to the linear alkanediyl group. Having a side chain of, for example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group Group, a branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
Cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1,2-diyl group, cyclohexane-1,4-diyl group, cyclo A monocyclic divalent alicyclic saturated hydrocarbon group which is a cycloalkanediyl group such as an octane-1,2-diyl group and a cyclooctane-1,5-diyl group;
Norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group and the like A divalent alicyclic saturated hydrocarbon group etc. are mentioned.
The hydrogen atom contained in the saturated hydrocarbon group may be replaced with a fluorine atom, preferably with at least one fluorine atom, more preferably with two or more fluorine atoms, and with three or more fluorine atoms. It is more preferable to replace However, it is preferable that the hydrogen atoms contained in the carbon atoms adjacent to X ^a and X ^b are not replaced by fluorine atoms.
Both X ^a and X ^b are preferably oxygen atoms.
The ring containing X ¹¹ , X ^a and X ^b is preferably a 4 to 12 membered ring, more preferably a 5 to 12 membered ring, still more preferably a 5 to 10 membered ring, and particularly preferably 6 to It is a 10-membered ring.

The partial structure represented by the formula (IB) is preferably the partial structure represented by the formula (IB).
[In the formula (I-BA),
X ^a , X ^b , R ³ and A ¹ have the same meanings as described above.
R ^f1 and R ^f2 independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
n represents an integer of 1 to 10. When n is 2 or more, a plurality of R ^f1 and R ^f2 that are present may be the same or different.
* Is a bond. ]

Examples of the fluorinated alkyl group for R ^f1 and R ^f2 include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. , Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1, 2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2 , 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl)ethyl group ,1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,4,4,5,5-decafluoropentyl group Group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2-(perfluorobutyl)ethyl group, 1,1,2,2,3 , 3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and A perfluorohexyl group may be mentioned. Of these, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group and the like are preferable.
Both R ^f1 and R ^f2 are preferably fluorine atoms.
n is preferably an integer of 1 to 8, more preferably an integer of 1 to 6, and even more preferably an integer of 1 to 4.
X ^a and X ^b are preferably the same atom, and more preferably both oxygen atoms.

When both X ^a and X ^b are oxygen atoms, the ring includes —O—C—O— represented below. * Is a bond.

The structural moiety represented by the formula (I-BA) preferably has the following structural moieties.

The ring in which A ¹ and R ³ are bonded to each other and may have a heteroatom formed together with the carbon atom to which they are bonded preferably has a structure represented by the formula (aa1).
[In formula (aa1),
X ^a , X ^b , X ² and * have the same meanings as described above.
Ring W represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group or a hydrocarbon group having 1 to 12 carbon atoms, and the methylene group contained in the hydrocarbon group is an oxygen atom or a carbonyl group. It may be replaced by a group. ]

Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms in the ring W include rings represented by formula (Iaa-1) to formula (Iaa-11), and preferably alicyclic having 5 to 18 carbon atoms. Examples thereof include a hydrocarbon group, more preferably a ring represented by formula (Iaa-1), a ring represented by formula (Iaa-2) or a ring represented by formula (Iaa-3).
Any carbon atom in the ring represented by formula (Iaa1-1) to formula (Iaa1-11) may be bonded to X ^a and X ^b, and any carbon atom may have * in formula (aa1). It may be a bond represented by.

Among them, the ring W is preferably a ring represented by the formula (Iaa-1), a ring represented by the formula (Iaa-2) or a ring represented by the formula (Iaa-3), and Those having a bond at a position are more preferable.

The hydrogen atom contained in the alicyclic hydrocarbon group of formula (Iaa-1) to formula (Iaa-11) may be substituted with a hydrocarbon group having 1 to 12 carbon atoms. The hydrocarbon group having 1 to 12 carbon atoms is preferably saturated hydrocarbon, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, Examples thereof include linear or branched saturated hydrocarbons such as decyl group, undecyl group and dodecyl group, aromatic hydrocarbon groups such as phenyl group and naphthyl group, and cyclic saturated hydrocarbons such as the groups shown below.

The group in which the methylene group contained in the hydrocarbon group in formulas (Iaa-1) to (Iaa-11) is substituted with an oxygen atom or a carbonyl group is a methoxy group, an ethoxy group, a propoxy group, a butoxy group, pentyl. Examples thereof include an oxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, a carboxyl group, a methoxycarbonyl group and an ethoxycarbonyl group.
Among them, the ring W preferably has a hydroxy group, an alkoxy group, or an alkoxycarbonyl group as a substituent.

Examples of the anion having 3 to 18 fluorine atoms and having a cyclic structure include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.
Examples of the acid generator (Ba) include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts).

The acid generator (Ba) is preferably an acid generator represented by the formula (I).
[In the formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ² represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. The contained hydrogen atom may be substituted with a fluorine atom.
The ring W represents an alicyclic hydrocarbon ring having 3 to 30 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. It may be substituted.
R ^f1 and R ^f2 independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
n represents an integer of 1 to 8.
Z ⁺ represents an organic cation.
However, the number of fluorine atoms contained in the anion of formula (I) is 3 to 18. ]

In formula (I), a compound having a negative charge formed by removing an organic cation represented by Z ⁺ having a positive charge may be referred to as a “sulfonate anion”.

Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, Examples thereof include a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group.
Q ¹ and Q ² are preferably, independently of each other, a trifluoromethyl group or a fluorine atom, and more preferably both are a fluorine atom.

Examples of the divalent saturated hydrocarbon group represented by L ² include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and two or more of these groups. It may be a combination of.
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.

The methylene group contained in the divalent saturated hydrocarbon group represented by L ² is represented by any of formula (b1-1) to formula (b1-3) as a group substituted with an oxygen atom or a carbonyl group. And the groups mentioned above. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with -W.
[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, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
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, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
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, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number of L ^b6 and L ^b7 is 23 or less. ]

In addition, in formula (b1-1) to formula (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbon atoms before replacement is calculated as the saturated hydrocarbon group. The carbon number of.
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 an alkanediyl 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 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, The methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Among them, the group represented by the formula (b1-1) or the formula (b1-3) is preferable.

Examples of formula (b1-1) include groups represented by formula (b1-4) to formula (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.
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 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 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.
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 saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
However, the total carbon number of L ^b13 , L ^b14, and L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
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 saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
However, the total carbon number of L ^b16 , L ^b17, and L ^b18 is 19 or less. ]

L ^b8 is preferably an alkanediyl 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 preferably represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 preferably represents 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 formula (b1-3) include groups represented by formula (b1-9) to formula (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 may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. .. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with 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 may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. .. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with 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 may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. .. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
^However, L ^b24, the total number of carbon atoms of ^{L b25} and ^{L b26} is 21 or less. ]

In the formulas (b1-9) to (b1-11), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms in the acyloxy group, CO and O in the ester bond. The number of carbon atoms in the saturated hydrocarbon group is also included.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group and an adamantylcarbonyloxy group.
Examples of the acyloxy group having a substituent include an oxoadamantylcarbonyloxy group, a hydroxyadamantylcarbonyloxy group, an oxocyclohexylcarbonyloxy group, a hydroxycyclohexylcarbonyloxy group, and the like.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-4) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-5) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-6) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-7) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-8) include the following.

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

Among the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-9) include the following.

Among the groups represented by formula (b1-3), examples of the group represented by formula (b1-10) include the following.

Among the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-11) include the following.

Examples of the sulfonate anion include the following anions.

The sulfonate anion is preferably an anion represented by formula (Ia-2-1) to formula (Ia-2-9).

Examples of the organic cation represented by Z ⁺ include organic onium cations such as 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.

Among them, cations represented by formulas (b2-1) to (b2-4) (hereinafter, may be referred to as “cation (b2-1)” depending on the formula number) are preferable.
[In the formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represent an aliphatic 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 aliphatic 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. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group. 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 together form a ring containing a sulfur atom to which they are bound, and the -methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group. Good.
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 represent the integer of 0-5 mutually independently.
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 an aliphatic 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 together form a ring containing a sulfur atom to which they are bound, and the methylene group contained in the ring is replaced with an oxygen atom, a sulfur atom, a sulfinyl group or a carbonyl group. May be.
R ^b11 represents a hydrogen atom, an aliphatic 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 an aliphatic 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 in the aliphatic hydrocarbon group, The contained 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 a carbon atom having 1 carbon atom. It may be substituted with an alkylcarbonyloxy group of -12.
R ^b11 and R ^b12 may be bonded together to form a ring containing —CH—CO—, and the methylene group contained in the ring may be an oxygen atom, a sulfinyl group or a carbonyl group. It may be replaced.
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 represent the integer of 0-4 independently of each other.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13 may be the same or different, when p2 is 2 or more, a plurality of R ^b14 may be the same or different, and when q2 is 2 or more R ^b15 may be the same or different, when r2 is 2 or more, R ^b16 may be the same or different, and when s2 is 2 or more, R ^b17 is ^They may be the same or different, and when t2 is 2 or more, a plurality of R ^b18 may be the same or different. ]

Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group and an n-octyl group. Group and an alkyl group of a 2-ethylhexyl group. Among them, the number of carbon atoms of the aliphatic hydrocarbon group of R ^{b9 to} R ^b12 is preferably 1 to 12.
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 cycloheptyl group. Examples thereof include cycloalkyl groups such as groups, cyclooctyl groups and cyclodecyl groups. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.
Especially, 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 in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include, for example, methylcyclohexyl group, dimethylcyclohexyl group, 2-alkyladamantan-2-yl group, methylnorbornyl group, isobornyl Groups and the like. In the alicyclic hydrocarbon group having a hydrogen atom substituted with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

As the aromatic hydrocarbon group, phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-adamantylphenyl group And aryl groups such as biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group.
When the aromatic hydrocarbon group contains an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms Groups are 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 aliphatic 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.

As the alkoxy group, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-decyloxy group and An n-dodecyloxy group etc. are mentioned.
Examples of the acyl group include an acetyl group, a propionyl group and an n-butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkylcarbonyloxy group, a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include an n-pentylcarbonyloxy group, an n-hexylcarbonyloxy group, an n-octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group.

The ring containing a sulfur atom formed by R ^b4 and R ^b5 together may be any ring of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated. .. Examples of this ring include rings having 3 to 18 carbon atoms, and preferably rings having 4 to 18 carbon atoms. Examples of the ring containing a sulfur atom include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and specifically the following rings.

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 includes 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings, for example, thiolane-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring. , 1,4-oxathian-4-ium ring and the like.
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. Examples of this ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and specifically, an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, an oxoadamantane ring. Etc.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, and the cation represented by the formula (Ic) is more preferable.
[In the formula (I-c),
^{R II3, R II4, R II5} , R II6 and ^{R II7,} independently of each other, hydrogen atom, hydroxy group, an alkyl group having 1 to 12 carbon atoms, a methylene group contained in the alkyl group, an oxygen atom or It may be replaced with a carbonyl group.
The methylene group contained in the ring containing the sulfonyl cation may be replaced by an oxygen atom, a sulfur atom or a carbonyl group.
r represents an integer of 1 to 3.
s represents an integer of 0 to 3.
R ^II8 represents an alkyl group having 1 to 6 carbon atoms. When s is 2 or more, a plurality of R ^II8 may be the same or different. ]

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.

Among them, cations (b2-c-21) to cations (b2-c-27), which are cations represented by the formula (Ic), are preferable.

Examples of the acid generator (Ba) include the acid generators shown in Table 1. In Table 1, salt (I-1) is an acid generator shown below.

Examples of the acid generator (Ba) include an acid generator (I-2), an acid generator (I-3), an acid generator (I-6), an acid generator (I-7), and an acid generator (I). -7), acid generator (I-10), acid generator (I-11), acid generator (I-14), acid generator (I-15), acid generator (I-19), acid The generator (I-20), the acid generator (I-23), the acid generator (I-24), the acid generator (I-26) and the acid generator (I-27) are preferable.

The acid generator represented by the above formula (I), which is a typical example of the acid generator (Ba), includes, for example, a salt represented by the formula (Ia) and a compound represented by the formula (Ib). Can be produced by reacting with and in a solvent such as 1,2-dichloroethane under an acid catalyst condition such as p-toluenesulfonic acid.
[In the formula, all symbols have the same meanings as described above. ]

The salt represented by the formula (Ia) can be synthesized by the method described in JP2007-224008A.
Examples of the compound represented by the formula (Ib) include 2,2,3,3-tetrafluoro-1,4-butanediol.

The resist composition of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as “acid generator (B1)”) in addition to the acid generator (Ba).
The acid generator (B1) may be a nonionic acid generator or an ionic acid generator. Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate) and sulfones. (For example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

Examples of the acid generator (B1) preferably include those represented by formulas (B1-1) to (B1-40), among which formula (B1-1) and formula (B1) containing an arylsulfonium cation. -2), formula (B1-3), formula (B1-5), formula (B1-6), formula (B1-7), formula (B1-11), formula (B1-12), formula (B1- 13), formula (B1-14), formula (B1-17), formula (B1-20), formula (B1-21), formula (B1-23), formula (B1-24), formula (B1-25). ), formula (B1-26), formula (B1-29), formula (B1-31), formula (B1-32), formula (B1-33), formula (B1-34), formula (B1-35). , (B1-36), (B1-37), (B1-38), (B1-39), or (B1-40).

When the resist composition of the present invention contains an acid generator (B1), the ratio of the content of the acid generator (Ba) and the acid generator (B1) (acid generator (Ba):acid generator (B1)) Is generally 5:95 to 95:5, preferably 10:90 to 90:10, and more preferably 15:85 to 85:15 on a mass basis.
In the resist composition, the content of the acid generator is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 40 parts by mass or less with respect to 100 parts by mass of the resin (A1). And more preferably 35 parts by mass or less. When both the acid generator (Ba) and the acid generator (B1) are contained, this content can be the total content thereof.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and usually 99.9% by mass or less. , And preferably 99% by mass 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 contain 1 type independently and may contain 2 or more types.

<Quencher (C)>
Examples of the quencher (C) include salts having a weaker acidity than the acid generated from the basic nitrogen-containing organic compound or the acid generator (B).
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 amines, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, Heptyl amine, octyl amine, nonyl amine, decyl amine, dibutyl amine, dipentyl amine, dihexyl amine, diheptyl amine, dioctyl amine, dinonyl amine, didecyl amine, triethyl amine, trimethyl amine, tripropyl amine, tributyl amine, tripentyl amine, trihexyl amine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, tri Isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3'-Diethyldiphenylmethane, piperazine, morpholine, piperidine and hindered amine compounds having a piperidine skeleton described in JP-A-11-52575, imidazole, 4-methylimidazole, 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′-dipyridylamine , 2,2′-dipicolylamine, bipyridine, and the like, preferably diisopropylaniline, and more preferably 2,6-diisopropylaniline.

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.

Examples of the salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) include a salt represented by the following formula, a weak acid inner salt represented by the formula (D), and JP-A-2012-2012. Salts described in JP-A-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745 can be mentioned. A weak acid inner salt represented by the formula (D) (hereinafter sometimes referred to as “weak acid inner salt (D)”) is preferable.
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 which generates an acid having a weaker acidity than the acid generated from the salt (I) and the acid generator (B) is a salt whose acid dissociation constant of the acid generated from the salt is usually -3<pKa, A salt of -1<pKa<7 is preferable, and a salt of 0<pKa<5 is more preferable.

[In the formula (D),
R ^D1 and R ^D2 are, independently of each other, a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, and an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m′ and n′ each independently represent an integer of 0 to 4, when m′ is 2 or more, a plurality of R ^D1 may be the same or different, and when n′ is 2 or more, A plurality of R ^D2 may be the same or different. ]

In the weak acid inner salt (D), as the hydrocarbon group of R ^D1 and R ^D2, a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group and The group etc. which are formed by combining these are mentioned.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group and nonyl group.
The monovalent alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be saturated or unsaturated. Examples thereof include cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, cyclohexyl groups, cyclononyl groups, cycloalkyl groups such as cyclododecyl groups, norbornyl groups, adamantyl groups, and the like.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4- Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-tert-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group And aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.
The group formed by combining these includes an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (for example, a phenylmethyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenyl- group. 1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group etc.) and the like.

Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, a cyclohexanecarbonyl group and the like.
Examples of the acyloxy group include groups in which an oxy group (—O—) is bonded to the above acyl group.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.

In the formula (D), R ^D1 and R ^D2 are independently of each other an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms. An acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group or a halogen atom is preferable.
m′ and n′ are preferably, independently of each other, an integer of 0 to 2, and more preferably 0. When m′ is 2 or more, the plurality of R ^D1 may be the same or different, and when n′ is 2 or more, the plurality of R ^D2 may be the same or different.

The weak acid inner salt (D) includes the following compounds.

The weak acid inner salt (D) can be produced by the method described in "Tetrahedron Vol. 45, No. 19, p6281-6296". As the weak acid inner salt (D), a commercially available compound can be used.

The content of the quencher (C) in the solid content of the resist composition is preferably 0.01 to 5% by mass, more preferably 0.01 to 4% by mass, and further preferably 0.01 to 3% by mass. %.

<Other ingredients>
The resist composition may contain a component other than the above-mentioned components (hereinafter sometimes referred to as “other component (F)”), if necessary. As the other component (F), additives known in the resist field, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A1), an acid generator (B), and optionally a resin (A2), a solvent (E), a quencher (C) and other components (F). Can be prepared by mixing 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 kind of resin and the solubility of the resin in the solvent (E) and 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 respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[Method for 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) a step of 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.

The resist composition can be applied onto the substrate 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, for example, 50 to 200° C., and the heating time is preferably, for example, 10 to 180 seconds. In addition, the pressure for 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. Although various light sources can be used as the exposure light source, ArF excimer laser (wavelength 193 nm) is preferable. 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 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 device. 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.

As the developing solution, a developing solution containing an organic solvent (hereinafter sometimes referred to as "organic developing solution") is preferable. By using an organic developer, a negative resist pattern can be produced from the resist composition of the present invention.
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 substantially only the organic solvent. Is more preferable.
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. More preferably, it is only butyl acetate and/or 2-heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a small amount of water.
At the time of development, the development may be stopped by substituting 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 the 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 for 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. More preferably used as a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and further used as a resist composition for ArF excimer laser exposure. It is preferably used and 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 + guardcolumn (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)

The structure of the compound was confirmed by measuring the molecular 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 peak is indicated by "MASS".

Synthesis Example 1: Synthesis of acid generator represented by formula (I-26)

10.00 parts of a compound represented by the formula (I-26-b) obtained by the method described in JP 2008-209917 A, a salt represented by the formula (I-26-a) 11.26. Parts, chloroform 50 parts and ion-exchanged water 25 parts were charged, and the mixture was stirred at 23° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and filtered to obtain the salt represented by the formula (I-26-c). Obtained 75 parts.

11.71 parts of the salt represented by the formula (I-26-c), 1.70 parts of the compound represented by the formula (I-26-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was heated at 23° C. for 30 minutes. It was stirred. 0.12 parts of copper(II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100° C. for 30 minutes. The obtained reaction solution was concentrated. Chloroform (50 parts) and ion-exchanged water (12.50 parts) were added to the obtained residue, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. 12.50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. This water washing operation was repeated 8 times. The obtained organic layer was concentrated. To the obtained residue, 50 parts of tert-butyl methyl ether was added, stirred and filtered to obtain 6.84 parts of a salt represented by the formula (I-26-e).

4.98 parts of the salt represented by the formula (I-26-e) and 25.00 parts of chloroform were charged, and the mixture was stirred at 23°C for 30 minutes. Thereafter, 2.17 parts of the compound represented by the formula (I-26-f) and 0.09 part of sulfuric acid were added, and the mixture was refluxed and stirred at 60°C for 15 hours. The obtained reaction product was cooled to 23° C., 120 parts of ion-exchanged water was added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. The collected organic layer was charged with 12.50 parts of ion-exchanged water, stirred at 23° C. for 30 minutes, and separated to collect the organic layer. This washing operation was repeated 7 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10 parts of acetonitrile was added to the obtained concentrate to dissolve and concentrate. To this, 41.35 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 4.84 parts of the acid generator represented by the formula (I-26).
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 2: Synthesis of acid generator represented by formula (I-22)
300 parts of the salt represented by the formula (I-22-a) and 750 parts of chloroform were charged and stirred at 23° C. for 30 minutes. Thereafter, 97.07 parts of the compound represented by the formula (I-22-b) was added, and the mixture was stirred at 23° C. for 1 hr and then concentrated. 1400 parts of tert-butyl methyl ether was added to the obtained concentrated residue, and the mixture was stirred and filtered to obtain 347.86 parts of the salt represented by the formula (I-22-c).

300 parts of the salt represented by the formula (I-22-c), 60.78 parts of the compound represented by the formula (I-22-d) and 1500 parts of chloroform were charged, and the mixture was stirred at 23° C. for 30 minutes. 1.19 parts of copper (II) diacetate was added to the obtained mixed liquid, and the mixture was further refluxed with stirring at 60° C. for 5 hours. The obtained reaction solution was concentrated. To the obtained concentrated residue, 50 parts of acetonitrile and 1200 parts of tert-butyl methyl ether were added, stirred and filtered to obtain 201.95 parts of the salt represented by the formula (I-22-e).

130 parts of the compound represented by the formula (I-22-f), 73.83 parts of the compound represented by the formula (I-22-g) and 780 parts of chloroform were charged, and the mixture was stirred at 23°C for 30 minutes. 0.46 parts of sulfuric acid was added dropwise to the obtained mixed solution, and the mixture was stirred under reflux at 62°C for 24 hours and cooled to 23°C. By adding 2.3 parts of triethylamine to the obtained reaction solution, a solution (purity 18.7%) containing 151.55 parts of the salt represented by the formula (I-22-h) was obtained.

50 parts of a solution (purity 18.7%) containing 151.55 parts of a salt represented by formula (I-22-h), 62.53 parts of a salt represented by formula (I-22-e) and 5% 204 parts of oxalic acid water was charged, and the mixture was stirred at 23° C. for 2 hours and separated. 204 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. This operation of washing with water was performed 4 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile and 830 parts of tert-butyl methyl ether were added to the obtained concentrated residue, and the mixture was stirred, filtered, and filtered to give the acid generator of the formula (I-22) 109. 76 parts were obtained.
MASS (ESI (+) Spectrum): M ⁺ 235.2
MASS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 3: Synthesis of acid generator represented by formula (I-18-d)
5.62 parts of the salt represented by the formula (I-18-a) and 16.85 parts of chloroform were charged, and the mixture was stirred at 23° C. for 30 minutes. Thereafter, 1.65 parts of the compound represented by the formula (I-18-b) was added, and the mixture was stirred at 23°C for 1 hr. The resulting reaction product was charged with 40 parts of a solution (purity 18.7%) containing 151.55 parts of the salt represented by the formula (I-22-h), and the mixture was stirred at 23° C. for 3 hours. 16 parts of ion-exchanged water was added to the obtained reaction product, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. This washing operation was repeated 5 times. The organic layer obtained was concentrated, and 65 parts of tert-butyl methyl ether was added to the obtained concentration residue, and the mixture was stirred and filtered to give a salt of the formula (I-18-d) 8.67. I got a part.

Synthesis Example 4: Synthesis of acid generator represented by formula (I-18)
3.91 parts of the salt represented by the formula (I-18-d), 0.44 part of the compound represented by the formula (I-18-e), 6 parts of monochlorobenzene and 16 parts of chloroform were charged, and at 23°C. Stir for 30 minutes. 0.01 part of copper(II) diacetate was added to the obtained mixed liquid, and the mixture was further stirred under reflux at 75° C. for 3 hours. The obtained reaction solution was cooled to 23° C., 8 parts of 5% oxalic acid water was added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. To the obtained organic layer, 8 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes. Then, it left still and liquid-separated. This operation of washing with water was performed 4 times. The obtained organic layer is concentrated, 8 parts of tert-butyl methyl ether and 33 parts of n-heptane are added to the obtained concentration residue, and the mixture is stirred and filtered to obtain a compound represented by the formula (I-18). 2.77 parts of an acid generator was obtained.
MASS (ESI (+) Spectrum): M ⁺ 221.1
MASS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 5: Synthesis of acid generator represented by formula (I-23)
Charge 2.76 parts of the salt represented by the formula (I-23-a), 2.12 parts of the compound represented by the formula (I-23-b) and 28.35 parts of chloroform, and stir at 23° C. for 30 minutes. did. 0.01 part of sulfuric acid was added to the obtained mixed solution, and the mixture was refluxed and stirred at 60° C. for 20 hours, and cooled to 23° C. 18 parts of ion-exchanged water was added to the obtained reaction solution, and the mixture was stirred at 23°C for 30 minutes. Then, it left still and liquid-separated. This operation of washing with water was performed 4 times to obtain an organic layer containing a salt represented by the formula (I-23-c).

The organic layer containing the salt represented by the formula (I-23-c) was charged with 2.54 parts of the salt represented by the formula (I-23-d) and 14.18 parts of 5% oxalic acid water, and 23 It stirred at 4 degreeC for 4 hours, and liquid-separated. 14 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. This operation of washing with water was performed 4 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23° C. for 30 minutes, and filtered. The filtrate was concentrated, 13 parts of acetonitrile and 25 parts of tert-butyl methyl ether were added to the obtained concentrated residue, and the mixture was stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 2.94 parts of the acid generator represented by the formula (I-23).
MASS (ESI (+) Spectrum): M ⁺ 235.2
MASS (ESI(-)Spectrum): M ^- 517.1

Synthesis Example 6: Synthesis of acid generator represented by formula (I-57)
Charge 5.60 parts of the salt represented by the formula (I-57-b), 24 parts of chloroform, 3.55 parts of the salt represented by the formula (I-57-a) and 4.88 parts of acetonitrile at 23° C. It was stirred for 72 hours. To the resulting reaction solution, 8.5 parts of ion-exchanged water was added and washed with water. This operation was repeated 5 times. The collected organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and filtered to generate an acid of the formula (I-57). 11.75 parts of the agent was obtained.
MASS (ESI (+) Spectrum): M ⁺ 221.1
MASS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 7: Synthesis of acid generator represented by formula (I-61)
The salt represented by the formula (I-61-a) was synthesized by the method described in JP2007-224008A.
10.00 parts of the salt represented by the formula (I-61-a) and 40 parts of 1,2-dichloroethane were charged, and the mixture was stirred at 23°C for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (I-61-b) and 0.30 part of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100° C. for 3 hours. The obtained reaction product was cooled to 23° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% sodium hydrogen carbonate aqueous solution were added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. To the collected organic layer, 120 parts of ion-exchanged water was charged, and the mixture was stirred at 23° C. for 30 minutes and separated to collect the organic layer. This washing operation was repeated 7 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile was added to the obtained concentrate to dissolve and concentrate. To this, 8.14 parts of acetonitrile and 48.84 parts of tert-butyl methyl ether were added and stirred, stirred at 23° C. for 1 hour, filtered, and then the acid generator 8 represented by the formula (I-61) 8 0.25 parts was obtained.
MS (ESI(+)Spectrum): M ⁺ 263.1.
MS (ESI(-) Spectrum): M ^- 467.1.

Synthesis Example 8: Synthesis of acid generator represented by formula (I-65)
The salt represented by the formula (I-65-b) was synthesized by the method described in JP2008-94835A.
17.50 parts of the salt represented by the formula (I-65-a), 25.00 parts of the salt represented by the formula (I-65-b) (purity: 90.8%), 125.00 parts of chloroform and Ion-exchanged water (41.67 parts) was charged, and the mixture was stirred at 23°C for 12 hours to perform liquid separation. The collected organic layer was charged with 31.25 parts of ion-exchanged water, stirred, and separated. This washing with water was performed 9 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23° C. for 30 minutes, and filtered. The filtrate was concentrated. To the obtained concentrate, 50 parts of acetonitrile was added to dissolve it, and the mixture was concentrated. To the obtained residue, 173.13 parts of tert-butyl methyl ether was added, and the mixture was stirred and filtered to obtain a compound of formula (I-65 28.42 parts of the salt represented by -c) was obtained.

10.72 parts of the salt represented by the formula (I-65-c) and 42.88 parts of 1,2-dichloroethane were charged, and the mixture was stirred at 23° C. for 30 minutes. Then, 5.53 parts of the compound represented by the formula (I-65-d) and 0.30 part of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100° C. for 3 hours. The obtained reaction product was cooled to 23° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% sodium hydrogen carbonate aqueous solution were added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still and liquid-separated. To the collected organic layer, 120 parts of ion-exchanged water was charged, and the mixture was stirred at 23° C. for 30 minutes and separated to collect the organic layer. This washing operation was repeated 7 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile was added to the obtained concentrate to dissolve and concentrate. To this, 9.12 parts of acetonitrile and 54.72 parts of tert-butyl methyl ether were added and stirred, stirred at 23° C. for 1 hour, filtered, and then the acid generator 8 represented by the formula (I-65) 8 .49 parts were obtained.
MS (ESI(+) Spectrum): M ⁺ 305.1.
MS (ESI(-) Spectrum): M ^- 467.1.

Synthesis Example 9: Synthesis of acid generator represented by formula (B1-21)
30.00 parts of the compound represented by the formula (B1-21-b) obtained by the method described in JP 2008-209917 A, and the salt represented by the formula (B1-21 -a) 35.50. Parts, 100 parts of chloroform and 50 parts of ion-exchanged water were charged and stirred at 23° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 30 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and filtered to give the salt of the formula (B1-21-c) 48. 57 parts were obtained.

20.00 parts of the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged, and the mixture was stirred at 23°C for 30 minutes. .. 0.21 parts of copper(II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100° C. for 1 hour. The obtained reaction solution was concentrated, 200 parts of chloroform and 50 parts of ion-exchanged water were added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and liquid-separated to take out an organic layer. 50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, the obtained residue was dissolved in 53.51 parts of acetonitrile, concentrated, 113.05 parts of tert-butyl methyl ether was added, and the mixture was stirred and filtered to obtain a compound of formula (B1 Thus, 10.47 parts of the acid generator represented by -21) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 339.1

Synthesis Example 10: Synthesis of acid generator represented by formula (B1-22)
11.26 parts of the salt represented by the formula (B1-22-a), 10.00 parts of the compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of deionized water were charged, and the temperature was 23°C. It was stirred for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and filtered to obtain the salt represented by the formula (B1-22-c). Obtained 75 parts.

11.71 parts of the salt represented by the formula (B1-22-c), 1.70 parts of the compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was kept at 23° C. for 30 minutes. It was stirred. 0.12 parts of copper(II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100° C. for 30 minutes. The obtained reaction solution was concentrated, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and the organic layer was separated. 12.50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. This water washing operation was repeated 8 times. The obtained organic layer is concentrated, 50 parts of tert-butyl methyl ether is added to the obtained residue, and the mixture is stirred and filtered to give 6.84 parts of an acid generator represented by the formula (B1-22). Got
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below.
Hereinafter, these monomers are referred to as “monomer (a1-1-2)” and the like according to the formula numbers.

Synthesis Example 11 [Synthesis of Resin A1-1]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-2-1) and a monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-2-1):monomer (a4-0-3)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-1 having a weight average molecular weight of 7.8×10 ³ with a yield of 65%. This resin A1-1 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-2]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-2-1) and a monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-2-1):monomer (a4-0-3)] is The mixture was mixed so as to be 18.5:18.5:3.5:55:4.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-2 having a weight average molecular weight of 7.9×10 ³ with a yield of 63%. This resin A1-2 has the following structural units.

Synthesis Example 13 [Synthesis of Resin A1-3]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-2-1) and a monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-2-1):monomer (a4-0-3)] is The mixture was mixed at a ratio of 18.5:18.5:2.5:53:7.5, and propylene glycol monomethyl ether acetate was added in an amount of 1.5 mass times the total amount of the monomers to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin A1-3 having a weight average molecular weight of 8.1×10 ³ with a yield of 60%. This resin A1-3 has the following structural units.

Synthesis Example 14 [Synthesis of Resin A1-4]
As the monomer, a monomer (a1-1-2), a monomer (a2-1-1), a monomer (a3-1-1) and a monomer (a4-0-3) are used, and the molar ratio thereof is [monomer (a1-1 -2): Monomer (a2-1-1): Monomer (a3-1-1): Monomer (a4-0-3)] are mixed so as to be 50:20:25:5, and the total amount of monomers is 1.5 times by mass propylene glycol monomethyl ether acetate was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-4 having a weight average molecular weight of 8.2×10 ³ with a yield of 87%. This resin A1-4 has the following structural units.

Synthesis Example 15 [Synthesis of Resin A1-5]
As the monomer, a monomer (a1-1-2), a monomer (a3-2-1) and a monomer (a4-0-3) were used, and the molar ratio thereof was [monomer (a1-1-2):monomer (a3-2). -1): Monomer (a4-0-3)] was mixed so as to be 40:20:40, and propylene glycol monomethyl ether acetate in an amount of 1.5 mass times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-5 having a weight average molecular weight of 7.3×10 ³ with a yield of 65%. This resin A1-5 has the following structural units.

Synthesis Example 16 [Synthesis of Resin A1-6]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a2-1-1), a monomer (a3-2-1) and a monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a2-1-1):monomer (a3-2-1):monomer (a4-0-3)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-6 having a weight average molecular weight of 7.9×10 ³ with a yield of 60%. This resin A1-6 has the following structural units.

Synthesis Example 17 [Synthesis of Resin A1-7]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a2-1-1), a monomer (a3-2-1) and a monomer (a4-0-19) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a2-1-1):monomer (a3-2-1):monomer (a4-0-19)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-7 having a weight average molecular weight of 8.5×10 ³ with a yield of 55%. This resin A1-7 has the following structural units.

Synthesis Example 18 [Synthesis of Resin A1-8]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a2-1-1), a monomer (a3-2-1) and a monomer (a4-0-34) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a2-1-1):monomer (a3-2-1):monomer (a4-0-34)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-8 having a weight average molecular weight of 8.0×10 ³ with a yield of 65%. This resin A1-8 has the following structural units.

Synthesis Example 19 [Synthesis of Resin A1-9]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a3-2-1) and a monomer (a4-0-3) were used, and the molar ratio [monomer (a1-1 -3): Monomer (a1-2-11): Monomer (a3-2-1): Monomer (a4-0-3)] are mixed so as to be 18.5:18.5:60:3, Propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-9 having a weight average molecular weight of 7.8×10 ³ with a yield of 67%. This resin A1-9 has the following structural units.

Synthesis Example 20 [Synthesis of Resin A1-10]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a3-2-1) and a monomer (a4-0-19) were used, and the molar ratio [monomer (a1-1 -3): Monomer (a1-2-11): Monomer (a3-2-1): Monomer (a4-0-19)] are mixed so as to be 18.5:18.5:60:3, Propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-10 having a weight average molecular weight of 8.8×10 ^{3 in} a yield of 61%. This resin A1-10 has the following structural units.

Synthesis Example 21 [Synthesis of Resin A1-11]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a3-2-1) and a monomer (a4-0-34) were used, and their molar ratios [monomer (a1-1 -3): Monomer (a1-2-11): Monomer (a3-2-1): Monomer (a4-0-34)] are mixed so as to be 18.5:18.5:60:3, Propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-11 having a weight average molecular weight of 7.9×10 ^{3 in} a yield of 63%. This resin A1-11 has the following structural units.

Synthesis Example 22 [Synthesis of Resin A2-1]
As the monomer, a monomer (a5-1-1) and a monomer (a4-0-12) were used, and the molar ratio (monomer (a5-1-1):monomer (a4-0-12)) was 50:50. The mixture was mixed so as to obtain a solution by adding methyl isobutyl ketone in an amount of 0.6 times the total amount of the monomers. Azobis(2,4-dimethylvaleronitrile) as an initiator was added to this solution in an amount of 3 mol% based on the total amount of the monomers, and the mixture was heated at 70° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered to obtain a resin A2-1 having a weight average molecular weight of 1.5×10 ⁴ with a yield of 88%. .. This resin A2-1 has the following structural units.

Synthesis Example 23: Synthesis of Resin X1 As a monomer, a monomer (a1-1-2), a monomer (a2-1-1) and a monomer (a3-1-1) were used, and the molar ratio thereof [monomer (a1-1- 2): Monomer (a2-1-1): Monomer (a3-1-1)] is mixed so as to be 50:25:25, and propylene glycol monomethyl ether acetate is added in an amount of 1.5 mass times the total amount of the monomers. In addition, a solution was prepared. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The resin thus obtained is again dissolved in propylene glycol monomethyl ether acetate, the solution obtained is poured into a methanol/water mixed solvent to precipitate the resin, and this resin is filtered twice to perform reprecipitation, and the weight average is obtained. Resin X1 having a molecular weight of 8.8×10 ³ was obtained with a yield of 78%. This resin X1 has the following structural units.

<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in an amount by mass shown in Table 2 and filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1-1 to A1-11, A2-1, X1: resin A1-1 to resin A1-11, resin A2-1, resin X1
<Acid generator>
I-26: Acid generator represented by formula (I-26) I-22: Acid generator represented by formula (I-22) I-18: Acid generator represented by formula (I-18) Agent I-23: Acid generator represented by formula (I-23) I-57: Acid generator represented by formula (I-57) I-61: Acid represented by formula (I-61) Generator I-65: Acid generator represented by formula (I-65) I-18-d: Acid generator represented by formula (I-18-d) B1-21: Formula (B1-21) Acid generator represented by formula B1-22: Acid generator represented by formula (B1-22) B1-6: Acid generator represented by formula below (synthesized with reference to JP-A-2007-224008)
BX: triphenylsulfonium trifluoromethanesulfonate (manufactured by Wako Pure Chemical Industries, Ltd.)
<Compound (D)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)
<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<CD uniformity (CDU) evaluation>
A silicon wafer is coated with a composition for organic antireflection film (ARC-29; manufactured by Nissan Chemical Co., Ltd.) and baked at 205° C. for 60 seconds to give an organic reflection film having a film thickness of 78 nm on the wafer. The prevention film was formed. Next, the above resist composition was applied (spin-coated) on the organic antireflection film so that the film thickness after drying was 85 nm. After the coating, the silicon wafer was prebaked on the direct hot plate at the temperature described in the "PB" column of Table 2 for 60 seconds to form a composition layer. An ArF excimer stepper for immersion exposure (XT: 1900Gi; ASML, NA=1.35, 3/4 Annular XY polarized light) was used for a contact hole pattern (hole pitch 90 nm) on the silicon wafer on which the composition layer was formed. /Hole diameter 55 nm) was used, and the exposure amount was changed stepwise for exposure. Ultrapure water was used as the immersion medium.
After the exposure, post-exposure bake was performed on the hot plate at the temperature described in the "PEB" column of Table 2 for 60 seconds. Then, the composition layer on the silicon wafer is developed by butyl acetate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a developing solution at 23° C. for 20 seconds by a dynamic dispensing method to form a negative resist pattern. Manufactured.

In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask becomes 50 nm was defined as the effective sensitivity.

In terms of effective sensitivity, the hole diameter of a pattern formed by a mask having a hole diameter of 55 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 calculated by using the population obtained by measuring the average hole diameter of the pattern formed by the mask having the hole diameter of 70 nm in the same wafer at 400 points,
When the standard deviation is 2.00 nm or less, it is evaluated as showing a good CDU, and "○" is given.
When the standard deviation was larger than 2.00 nm, the CDU was evaluated to be insufficient, and was designated as "x". The results are shown in Table 3.

From the above results, it can be seen that the resist composition of the present invention can produce a resist pattern with good CD uniformity (CDU).

The resist composition of the present invention is suitable for fine processing of semiconductors because the resist pattern is excellent in CD uniformity (CDU) of the obtained resist pattern.

Claims (8)

Table formula resin (A1) containing a structural unit having the structural unit and acid labile group represented by (a4-0), having 3 to 18 fluorine atoms, and formula (I-B) Resist composition containing an acid generator (Ba) containing an anion having a cyclic structure.
[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]
[In the formula (IB),
A ¹ represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
R ³ represents a hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The contained hydrogen atom may be substituted with a hydroxy group. A ¹ and R ³ may be bonded to each other to form a ring which may have a hetero atom together with the carbon atom to which they are bonded.
X ^a and X ^b each independently represent an oxygen atom or a sulfur atom.
X ² represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms, which may have a fluorine atom.
* Is a bond. ] The resist composition according to claim 1, wherein L ³ is a perfluoroalkanediyl group having 1 to 2 carbon atoms. The resist composition according to claim 1, wherein R ⁶ is a fluorine atom. Content rate of the structural unit represented by Formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less with respect to the sum total of all the structural units of resin (A1). The resist composition according to any one of 1. The resist composition according to claim 1, wherein the structural unit having an acid labile group has a structural unit represented by formula (a1-1) or a structural unit represented by formula (a1-2). ..
[In Formula (a1-1) and Formula (a1-2),
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 a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
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 combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ] The resist composition according to any one of claims 1 to 5 containing a salt capable of generating a weak acid acidity than the acid generated from the acid generator further. Resist composition comprises a structural unit having a fluorine atom, and the resist composition according to any one of claims 1-6, further containing a resin (A2) which does not include a structural unit having an acid labile group. (1) applying the resist composition according to any one of claims 1 to 7 coated on a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) a step of exposing the composition layer,
A method for producing a resist pattern, comprising: (4) heating the composition layer after exposure, and (5) developing the composition layer after heating.