JP6435166B2 - Resin, resist composition and method for producing resist pattern - Google Patents

Description

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

Patent Document 1 describes a resist composition comprising a resin comprising a combination of the following structural units and an acid generator.
Patent Document 2 describes a resist composition comprising a resin comprising a combination of the following structural units and an acid generator.

JP 2010-256856 A JP 2011-138003 A

  In the resist pattern formed by the above resist composition, the resolution may not be satisfied.

The present invention includes the following inventions.
[1] A structural unit represented by formula (I) and at least one structural unit selected from the structural unit represented by formula (a1-1) and the structural unit represented by formula (a1-2) Contains resin.
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ^{2 to} R ⁴ each independently represents an alkyl group having 1 to 6 carbon atoms, or R ² and R ³ are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. .
X ¹ represents a single bond, —CO—O— * or —CO—NR ⁵ — *, * represents a bond to —Ar, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Represents.
X ² represents a single bond, * —O—L ¹ — or * —CO—O—L ² —, * represents a bond to —Ar, and L ¹ and L ² each independently represent carbon The alkanediyl group of number 1-4 is represented.
Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms. ]
[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 to —CO—. Represents 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 obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]
[2] The resin according to [1], wherein X ¹ and X ² are both single bonds.
[3] The resin according to [1] or [2], further comprising a structural unit represented by the formula (a2-A).
[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an 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.
A ^a50 represents a single bond or ^* —X ^a51 — (A ^a52 —X ^a52 ) _na —, and * represents a bond to the carbon atom to which —R ^a50 is bonded.
A ^a52 each independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent —O—, ^—CO —O— or —O—CO—.
na represents 0 or 1.
mb represents the integer of 0-4. When mb is an integer greater than or equal to 2, several ^Ra51 may mutually be same or different. ]
[4] The resin according to any one of [1] to [3], further comprising a structural unit that decomposes upon exposure to generate an acid.
[5] A resist composition comprising the resin according to any one of [1] to [4] and an acid generator.
[6] The resist composition according to [5], further comprising a salt having a lower acidity than the acid generated from the acid generator.
[7] (1) A step of applying the resist composition according to [5] or [6] on a substrate,
(2) The process of drying the composition after application | coating and forming 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,
A method for producing a resist pattern including:

  According to the resist composition containing the resin of the present invention, a resist pattern can be produced with good resolution.

In the present specification, unless otherwise specified, in the description of the structural formula of a compound, “aliphatic hydrocarbon group” means a linear or branched hydrocarbon group, and “alicyclic hydrocarbon group” means an aliphatic group. A group obtained by removing a number of hydrogen atoms corresponding to the valence from the ring of a cyclic hydrocarbon. The “aromatic hydrocarbon group” also includes a group in which a hydrocarbon group is bonded to an aromatic ring. When stereoisomers exist, all stereoisomers are included.
Further, in the present specification, "(meth) acrylic monomer", "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " at least one monomer having the structure Means. In the present specification, “(meth) acrylate” means “at least one of acrylate and methacrylate”. The notations such as “(meth) acrylic acid” and “(meth) acryloyl” have the same meaning. Moreover, in the group described in the present specification, any group that can take both a linear structure and a branched structure may be used.

<Resin (A)>
Resin (A) includes a structural unit represented by formula (I) (hereinafter sometimes referred to as “structural unit (I)”) and a structural unit represented by formula (a1-1) (hereinafter “structural unit ( a1-1) ”and at least one structural unit selected from the structural unit represented by formula (a1-2) (hereinafter sometimes referred to as“ structural unit (a1-2) ”) To do.
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ^{2 to} R ⁴ each independently represents an alkyl group having 1 to 6 carbon atoms, or R ² and R ³ are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. .
X ¹ represents a single bond, —CO—O— * or —CO—NR ⁵ — *, * represents a bond to —Ar, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Represents.
X ² represents a single bond, * —O—L ¹ — or * —CO—O—L ² —, * represents a bond to —Ar, and L ¹ and L ² each independently represent carbon The alkanediyl group of number 1-4 is represented.
Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms. ]

Examples of the alkyl group in R ^{2 to} R ⁴ include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, and a hexyl group.
The ring formed by combining R ² and R ³ with each other preferably has 3 to 12 carbon atoms.
Examples of the ring include an adamantane ring and a cyclohexane ring.

X ¹ is preferably a single bond or —CO—O— *, and more preferably a single bond.
X ² is preferably a single bond or * —O—L ¹ —, and more preferably a single bond.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include phenylene group, o-methylphenylene group, m-methylphenylene group, p-methylphenylene group, p-ethylphenylene group, p-tert-butylphenylene group, 1 -A naphthylene group, 2-naphthylene group, 1-anthrylene group, 9-anthrylene group, 1-phenanthrylene group and 2-phenanthrylene group are mentioned.
Ar is preferably a phenylene group.

Examples of the structural unit (I) include structural units represented by formulas (I-1) to (I-36), and are represented by formulas (I-1) to (I-9), respectively. Are preferably represented by the formula (I-1), formula (I-2), formula (I-4), formula (I-5), formula (I-7) or formula (I-8). The structural unit represented by Formula (I-1) or Formula (I-2) is more preferable.

In the structural units represented by formula (I-1) to formula (I-9), formula (I-16) to formula (I-21), and formula (I-28) to formula (I-30), respectively. , A structural unit in which a hydrogen atom corresponding to R ¹ is replaced by a methyl group, and formula (I-10) to formula (I-15), formula (I-22) to formula (I-27), and formula (I In the structural units represented by I-31) to Formula (I-36), the structural unit in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom is also exemplified as the structural unit (I).

The content of the structural unit (I) in the resin (A) is preferably 5 to 50 mol%, and preferably 5 to 40 mol% with respect to the total structural units of the resin (A) in terms of the shape of the resist pattern. More preferably, 10-30 mol% is further more preferable.
When the content of the structural unit (I) is within the above range, a resist pattern having a better focus margin can be manufactured.

As a monomer which derives the structural unit (I), for example, it can be produced by the following method. The structural unit (I) is derived from a compound represented by the formula (I) (hereinafter sometimes referred to as “compound (I)”).
[In the formula (I), R ¹ , R ² , R ³ , R ⁴ , X ¹ , X ² and Ar represent the same meaning as described above. ]

A compound represented by formula (I) is obtained by reacting a compound represented by formula (Ia) with a compound represented by formula (Ib) in a solvent in the presence of a catalyst. Can do.
Examples of the solvent include chloroform, tetrahydrofuran and toluene.
Examples of the catalyst include a base catalyst (for example, pyridine, dimethylaminopyridine) and a known esterification catalyst (for example, an acid catalyst, a carbodiimide catalyst, etc.), and a base catalyst and a known esterification catalyst may coexist. .
Examples of the compound represented by the formula (Ia) include salts represented by the following formula, and can be easily obtained from the market.
Examples of the compound represented by the formula (Ib) include salts represented by the following formula, and can be easily obtained from the market.
Examples of the carbodiimide catalyst include salts represented by the following formulas and can be easily obtained from the market.

The resin (A) contains at least one structural unit selected from the structural unit (a1-1) and the structural unit (a1-2). The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.
[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 to —CO—. Represents 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 obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is an integer of 1 to 4, preferably 1), more preferably − O-.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and a group obtained by combining these include the same groups as those described for R ^{a1 to} R ^a3 in formula (1).
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned. Among these, a monomer represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferable, and any one of formula (a1-1-1) to formula (a1-1-4) is preferable. The monomer represented by is more preferable.

As the monomer (a1-2), 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclohexane-1-yl ( And (meth) acrylate. Monomers represented by the formula (a1-2-1) to the formula (a1-2-12) are preferred, and the formula (a1-2-3) to the formula (a1-2-4) or the formula (a1-2-9) The monomer represented by formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferable.

When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually 10 to 95 mol with respect to all the structural units of the resin (A). %, Preferably 15 to 90 mol%, more preferably 20 to 85 mol%.
In the resin (A), the content ratio (mass ratio) of the structural unit (I) and the structural unit (a1-1) and / or the structural unit (a1-2) is 5:95 to 95: 5. Is preferably 5:95 to 70:30, and more preferably 5:95 to 50:50. When the resin (A) includes both the structural unit (a1-1) and the structural unit (a1-2), the content ratio of the structural unit (a1-1) and the structural unit (a1-2) is 5: It is preferably 95 to 95: 5, more preferably 30:70 to 95: 5, still more preferably 50:50 to 95: 5.

<Structural unit (a2-A)>
The resin (A) is preferably a resin further having a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as “structural unit (a2-A)”).
[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an 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.
A ^a50 represents a single bond or ^* —X ^a51 — (A ^a52 —X ^a52 ) _na —, and * represents a bond to the carbon atom to which —R ^a50 is bonded.
A ^a52 each independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent —O—, ^—CO —O— or —O—CO—.
na represents 0 or 1.
mb represents the integer of 0-4. When mb is an integer greater than or equal to 2, several ^Ra51 may mutually be same or different. ]

^Examples of the halogen atom for R ^a50 include a fluorine atom, a chlorine atom and a bromine atom.
^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R ^a50 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 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 Groups and n-perfluorohexyl groups.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group for R ^a51 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, and an n-hexyl group.
^Examples of the alkoxy group for R ^a51 include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a tert-butoxy group. A C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is more preferable.
^Examples of the acyl group for R ^a51 include an acetyl group, a propionyl group, and a butyryl group.
^Examples of the acyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* —X ^a51 — (A ^a52 —X ^a52 ) _na — includes ^* —O—, ^* —CO—O—, ^* —O—CO—, ^* —CO—O—A ^a52 —CO—O—, ^* —O—CO—A ^a52 —O—, ^* —O—A ^a52 —CO—O—, ^* —CO—O—A ^a52 —O—CO—, ^* —O—CO—A ^a52 —O—CO -. Of these, ^* —CO—O—, ^* —CO—O—A ^a52 —CO—O— or ^* —O—A ^a52 —CO—O— is preferable.

A ^a52 is preferably a methylene group or an ethylene group.

A ^a50 is preferably a single bond, ^* —CO—O— or ^* —CO—O—A ^a52 —CO—O—, and is preferably a single bond, ^* —CO—O— or ^* —CO—O—CH. _2- CO-O- is more preferable, and a single bond or ^* -CO-O- is more preferable.

mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxyl group is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

Examples of the structural unit (a2-A) include a structural unit represented by the formula (a2-0) (hereinafter may be referred to as “structural unit (a2-0)”).
[In formula (a2-0), R ^a50 , R ^a51 and mb represent the same meaning as described above. ]

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

  Examples of the monomer for deriving the structural unit (a2-A) include monomers described in JP 2010-204634 A and JP 2012-12577 A.

  When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably based on all structural units. It is 10-70 mol%, More preferably, it is 15-65 mol%.

<Structural unit (II)>
The resin (A) preferably further contains a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as “structural unit (II)”). It is preferably a structural unit containing a group represented by II-1) or formula (II-2).
[In Formula (II-1) and Formula (II-2),
A ^II1 and A ^II2 each independently represent a single bond or a divalent linking group.
R ^II1 , R ^II2 and R ^II3 each independently represents an organic group, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
A ⁻ represents a counter anion.
RA ⁻ represents an organic group containing an anion.
Z ^{a +} represents an organic cation. ]

No particular limitation is imposed on the divalent linking group of A ^II1, linear or branched aliphatic hydrocarbon group having 1 to 30 carbon atoms, alicyclic hydrocarbon group or a carbon of 3 to 36 carbon atoms 6 Represents an aromatic hydrocarbon group of ˜36 and a combination thereof, and the methylene group contained in the aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group is replaced with a hetero atom, a carbonyl group or a sulfonyl group. And the hydrogen atom contained in the aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 8 carbon atoms, or a carbon atom having 1 to 12 carbon atoms. May be substituted with an alkoxy group, an alkyl halide having 1 to 8 carbon atoms, or an oxo group.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and still more preferably 1 to 5.
The linear aliphatic hydrocarbon group is preferably a linear alkanediyl group, and is —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₃ —, — (CH _2). ) ₄ -,-(CH ₂ ) _5- and the like.
The branched aliphatic hydrocarbon group is preferably a branched alkanediyl group, specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH _{3) 2 -, - C (} CH 3) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 -, - CH (CH _{3) CH 2 -, - CH} (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH 3) _{2 -CH 2 -, - CH (} CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH ₃ ) CH ₂ CH ₂ — and the like.
A hydrogen atom contained in the linear or branched aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group of A ^II1 is a hydroxy group, an alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. It is preferably substituted with an alkoxy group of -12, a halogen atom, a halogenated alkyl group having 1 to 5 carbon atoms substituted with a halogen atom, an oxo group (= O) or the like, and substituted with a fluorine atom or a fluorine atom More preferably, it is substituted with a halogenated alkyl group having 1 to 5 carbon atoms or an oxo group.

The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
The alicyclic hydrocarbon group of A ^II1 preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane or norbornane. , Isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group of A ^II1 is a divalent hydrocarbon group having at least one monocyclic or polycyclic aromatic ring. The number of carbon atoms in the aromatic ring is preferably 4 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); two or more aromatic rings A group in which two hydrogen atoms have been removed from an aromatic compound containing, for example, biphenyl, fluorene, etc .; a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) A group in which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) And a group obtained by further removing one hydrogen atom from the aryl group.
The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the alicyclic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. A hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.
The group in which the methylene group contained in the aliphatic hydrocarbon group is substituted with a hetero atom is -O-, -C (= O) -O-, -C (= O)-, -O-C (= O). -O-, -C (= O) -NH-, -NH-, -NH-C (= NH)-(the hydrogen atom may be substituted with a substituent such as an alkyl group or an acyl group), -S -, - S (= O ) 2 -, - S (= O) 2 -O-, the formula ^{-A 21 -O-A 22 -,} - A 21 -O -, - A 21 -C (= O) —O—, — [A ²¹ —C (═O) —O] _{m ′} —A ²² — or —A ²¹ —O—C (═O) —A ²² — A ²¹ and A ²² are each independently a divalent hydrocarbon group which may have a substituent, and m ′ is an integer of 0 to 3. ] Is preferable.
When A ^II1 is —C (═O) —NH—, —NH—, —NH—C (═NH) —, the hydrogen atom may be substituted with a substituent such as an alkyl group or an acyl group. . The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
^{-A 21 -O-A 22 -,} - A 21 -O -, - A 21 -C (= O) -O -, - [A 21 -C (= O) -O] m '-A 22 - or In —A ²¹ —O—C (═O) —A ²² —, A ²¹ and A ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same divalent hydrocarbon groups that may have the substituents described in the description of the divalent linking group.
As A ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. preferable.
A ²² is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by — [A ²¹ —C (═O) —O] _{m ′} —A ²² —, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, 1 is more preferable, and 1 is particularly preferable. That is, as the group represented by — [A ²¹ —C (═O) —O] _{m ′} —A ²² —, a group represented by —A ²¹ —C (═O) —O—A ²² — is exemplified. Particularly preferred. Of these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ and b ′ are each independently an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. preferable.

A ^II1 is preferably a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkanediyl group, or a combination thereof.

In formula (II-1), R ^II1 , R ^II2 and R ^II3 are each independently an organic group, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. Good.
The organic groups of R ^{II1 to} R ^II3 are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.

Specific examples of the organic group for R ^II1 include an alkanediyl group which may have a substituent and an arylene group which may have a substituent.
Examples of the alkanediyl group which may have a substituent in R ^II1 include an unsubstituted alkanediyl group and a substituent in which part or all of the hydrogen atoms of the unsubstituted alkanediyl group are substituted with a substituent. Examples include alkanediyl groups.
The unsubstituted alkanediyl group may be linear or cyclic. From the viewpoint of excellent resolution, an alkanediyl group having 1 to 10 carbon atoms is preferable, and an alkanediyl group having 1 to 5 carbon atoms is more preferable. Specifically, methylene group, ethylene group, 1,3-propanediyl group, 1,2-propanediyl group, 1,4-butanediyl group, 1,3-butanediyl group, 1,5-pentanediyl group, cyclopentane A diyl group, a hexanediyl group, a cyclohexanediyl group, etc. are mentioned.

Examples of the substituent that the alkanediyl group which may have a substituent include a halogen atom, an oxo group (═O), a cyano group, an alkyl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (= O) —O—R ^{7 ″} , —O—C (═O) —R ^{8 ″} , —O—R ^{9 ″} , an aryl group, etc. R ^{7 ″} , R ^{8 ″} and R ^{9 ″} are respectively Independently, it is a hydrogen atom or a hydrocarbon group.
As a halogen atom, a fluorine atom, a chlorine atom, an iodine atom, a bromine atom, etc. are mentioned, A fluorine atom is preferable.

The alkyl group as a substituent of the alkanediyl group which may have a substituent may be a linear or branched alkyl group or a cycloalkyl group, but the carbon number thereof is 1-30. Is preferred.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The cycloalkyl group may be monocyclic or polycyclic. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. Specifically, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more groups from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
The cycloalkyl group is preferably polycyclic, preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and most preferably a group obtained by removing one or more hydrogen atoms from adamantane.
The alkyl group as a substituent in the alkanediyl group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

Examples of the alkoxyalkyloxy group as a substituent in the substituted alkanediyl group include:
Examples include a group represented by the general formula: —O—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ⁴⁹ .
[Wherein, R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom or a linear or branched alkyl group, and R ⁴⁹ represents an alkyl group. ]
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms and may be linear or branched, preferably an ethyl group or a methyl group, and most preferably a methyl group.
At least one of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom. In particular, it is more preferable that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be a linear or branched alkyl group or a cycloalkyl group.
The linear or branched alkyl group represented by R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. It is done.
The cycloalkyl group represented by R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane or bicycloalkane, tricycloalkane, tetracycloalkane, etc., and the hydrogen atom contained in the cycloalkane includes carbon It may be substituted with an alkyl group of formula 1-5, a fluorine atom or a fluorinated alkyl group. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

Examples of the alkoxycarbonylalkyloxy group as a substituent in the substituted alkanediyl group include a group represented by the general formula: —O—R ⁵⁰ —C (═O) —O—R ⁵⁶ .
[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵⁶ represents a tertiary alkyl group. ]
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a 1,1-dimethylethylene group, etc. Is mentioned.
The tertiary alkyl group for R ⁵⁶ includes a 2-methyl-2-adamantyl group, a 2- (2-propyl) -2-adamantyl group, a 2-ethyl-2-adamantyl group, and a 1-methyl-1-cyclopentyl group. 1-ethyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1- (1-adamantyl) -1-methylethyl group, 1- (1-adamantyl)- 1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1- (1-cyclopentyl) -1-methylethyl group, 1- ( 1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methylpentyl group; 1- (1 (Cyclohexyl) -1-methylethyl group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, Examples thereof include a tert-butyl group, a tert-pentyl group, and a tert-hexyl group.

Moreover, the general formula: the R ⁵⁶ in the ^{-O-R 50 -C (= O} ) -O-R 56, also include groups replaced by R ^{56 '.} R ^{56 ′} is a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an alicyclic hydrocarbon group that may contain a hetero atom.
^Examples of the alkyl group for R ^{56 ′} include the same alkyl groups as those described above for R ⁴⁹ .
^Examples of the fluorinated alkyl group for R ^{56 ′} include groups in which part or all of the hydrogen atoms in the alkyl group for R ⁴⁹ have been substituted with fluorine atoms.
Examples of the alicyclic hydrocarbon group which may contain a hetero atom of R ^{56 ′} include an alicyclic hydrocarbon group containing no hetero atom, an alicyclic hydrocarbon group containing a hetero atom in the ring structure, and an alicyclic ring. And those in which a hydrogen atom in the formula hydrocarbon group is substituted with a heteroatom.
Regarding R ^{56 ′} , examples of the alicyclic hydrocarbon group that does not contain a hetero atom include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Is mentioned. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
Regarding R ^{56 ′} , examples of the alicyclic hydrocarbon group containing a hetero atom in the ring structure include groups represented by formulas (L1) to (L6) and (S1) to (S4).
Wherein Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ^{94 ′} — or —S—R ^{95 ′} —, wherein R ^{94 ′} and R ^{95 ′} are Each independently represents an alkylene group having 1 to 5 carbon atoms, and m is an integer of 0 or 1.]

As for R ^{56 ′} , the hydrogen atom in the alicyclic hydrocarbon group is substituted with a hetero atom, and the hydrogen atom in the alicyclic hydrocarbon group is substituted with an oxo group (═O), etc. Can be mentioned.

R ^{7 ″} in —C (═O) —O—R ^{7 ″} is a hydrogen atom or a hydrocarbon group.
The hydrocarbon group for R ^{7 ″} may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. Any of a hydrogen group may be sufficient.

The saturated hydrocarbon group for R ^{7 ″} may be linear, branched or cyclic, or a combination thereof. The carbon number of the linear or branched saturated hydrocarbon group is 1-25 are preferable, 1-15 are more preferable, and 4-10 are more preferable.
Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Examples of the branched saturated hydrocarbon radicals, for example, tertiary alkyl groups mentioned in the description of the R ^56. Examples of the branched saturated hydrocarbon group other than the tertiary alkyl group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3- Examples thereof include a methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.
The hydrogen atom contained in the linear or branched saturated hydrocarbon group is substituted with, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, a carboxy group, or the like. May be.
As an alkoxy group as a substituent of the linear or branched saturated hydrocarbon group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, n -A butoxy group or a tert-butoxy group is preferable, and a methoxy group or an ethoxy group is most preferable.
Examples of the halogen atom as a substituent of the linear or branched saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent of the linear or branched saturated hydrocarbon group, part or all of the hydrogen atoms of the linear or branched saturated hydrocarbon group are substituted with the halogen atom. Group.
The number of carbon atoms of the cyclic saturated hydrocarbon group in R ^{7 ″} is preferably 3 to 20. The cyclic saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, for example, from monocycloalkane to 1 A group in which one hydrogen atom is removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. More specifically, cyclopentane, cyclohexane, Examples thereof include monocycloalkanes such as cycloheptane and cyclooctane, and groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic saturated hydrocarbon group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those described above as the substituent that the linear or branched alkyl group may have, an alkyl group having 1 to 5 carbon atoms, and the like.
The saturated hydrocarbon group for R ^{7 ″} may be a combination of a linear or branched saturated hydrocarbon group and a cyclic saturated hydrocarbon group.
As a combination of a linear or branched saturated hydrocarbon group and a cyclic saturated hydrocarbon group, a group in which a cyclic saturated hydrocarbon group is bonded as a substituent to a linear or branched saturated hydrocarbon group ( For example, 1- (1-adamantyl) methyl group), a group in which a linear or branched saturated hydrocarbon group is bonded to a cyclic saturated hydrocarbon group as a substituent.

The aliphatic unsaturated hydrocarbon group for R ^{7 ″} is preferably linear or branched. Examples of the linear aliphatic unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of branched aliphatic unsaturated hydrocarbon groups include 1-methylpropenyl group, 2-methylpropenyl group, etc. These linear or branched aliphatic unsaturated hydrocarbon groups. The group may have a substituent, and examples of the substituent include the same groups as those described above as the substituent that the linear or branched alkyl group may have.

The aromatic hydrocarbon group for R ^{7 ″} is a monovalent hydrocarbon group having at least one aromatic ring and may have a substituent. The aromatic ring may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms in the substituent. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, phenanthrene, etc .; some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atom, sulfur atom, nitrogen atom, etc. Specific examples of the aromatic heterocycle include pyridine ring and thiophene ring. Cited That.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); the aromatic hydrocarbon ring or aromatic heterocycle Groups in which one of the ring hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group, heteroarylalkyl group); and the like. The number of carbon atoms of the alkylene group that replaces the hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. .
The hydrogen atom of the aromatic hydrocarbon group may be substituted with an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O) or the like.
The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

Among the above, R ^{7 ″} is preferably a hydrogen atom, a saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group because of excellent lithography characteristics and resist pattern shape. Are more preferably a linear or branched saturated hydrocarbon group or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms.

^{-O-C (= O) "} R 8 ^in" -R ^8, and -O-R ^{9 "R 9 in"} is a hydrogen atom or a hydrocarbon group.
Examples of R ^{8 ″} and R ^{9 ″} include those similar to R ^{7 ″} . Among them, R ^{8 ″} and R ^{9 ″} are hydrogen atoms because of their good lithography characteristics and resist pattern shape. A saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group is preferable, a hydrogen atom, a linear or branched saturated hydrocarbon group having 1 to 15 carbon atoms, or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. More preferred.
As the substituent —O—R ^{9 ″} , a hydroxyl group and an alkoxy group having 1 to 5 carbon atoms are preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert- Most preferred is a butoxy group.

The aryl group as a substituent in the substituted alkylene group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The aryl group as the substituent may have a substituent. Examples of the substituent include those similar to those exemplified as the substituent which the aromatic hydrocarbon group for R ^{7 ″} may have.

In the formula (II-1), as the arylene group which may have a substituent in R ^II1, an unsubstituted arylene group having 6 to 20 carbon atoms; a part of hydrogen atoms of the unsubstituted arylene group or Examples thereof include a substituted arylene group which is entirely substituted with a substituent.
The unsubstituted arylene group is preferably an arylene group having 6 to 10 carbon atoms because it can be synthesized at a low cost, and examples thereof include a phenylene group and a naphthylene group.
Examples of the substituent in the substituted arylene group include the same groups as those described above as the substituent in the substituted alkylene group. Among those exemplified as the substituent in the substituted alkylene group, a halogen atom, an oxo group (═O) , Cyano group, alkyl group, alkoxyalkyloxy group, alkoxycarbonylalkyloxy group, —C (═O) —O—R ^{7 ″} , —O—C (═O) —R ^{8 ″} , —O—R ^{9 ″} (Wherein R ^{7 ″} , R ^{8 ″} and R ^{9 ″} are each independently a hydrogen atom, a saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group).

In formula (II-1), the organic group of R ^II2 and R ^II3 is not particularly limited, but may be an aryl group which may have a substituent, or an alkyl which may have a substituent. And an alkenyl group optionally having a substituent.

^Examples of the aryl group which may have a substituent in R ^II2 and R ^II3 include an unsubstituted aryl group having 6 to 20 carbon atoms; a part or all of the hydrogen atoms of the unsubstituted aryl group Examples include substituted aryl groups.
The unsubstituted aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
Examples of the substituent in the substituted aryl group include the same substituents as the substituents that the substituted arylene group may have.

Examples of the alkyl group in R ^II2 and R ^II3 include an unsubstituted alkyl group, a substituted alkyl group in which part or all of the hydrogen atoms of the unsubstituted alkyl group are substituted with a substituent, and the like.
The unsubstituted alkyl group may be a linear alkyl group or a cycloalkyl group. From the point which is excellent in resolution, a C1-C10 alkyl group is preferable and a C1-C5 alkyl group is more preferable. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. .
^Examples of the substituent in the substituted alkyl group include the same groups as those described above as the substituent that the substituted alkylene group in R ^II1 may have.

Examples of the alkenyl group in R ^II2 and R ^II3 include an unsubstituted alkenyl group and a substituted alkenyl group in which part or all of the hydrogen atoms of the unsubstituted alkenyl group are substituted with a substituent.
The unsubstituted alkenyl group is preferably linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5, and still more preferably 2 to 4. Specific examples include a vinyl group, a propenyl group (allyl group), a butynyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
^Examples of the substituent in the substituted alkenyl group include the same groups as those described above as the substituent that the substituted alkylene group in R ^II1 may have.

In formula (II-1), R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. The ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when one or both of R ^II2 and R ^II3 forming a ring is a cyclic group (cyclic alkyl group or aryl group), a polycyclic ring (fused ring) is formed when they are combined. The
As a ring to be formed, one ring containing a sulfur atom in its ring skeleton is preferably a 3 to 10-membered ring, particularly preferably a 5 to 7-membered ring, including the sulfur atom.
The ring may have a hetero atom other than the sulfur atom to which R ^II2 and R ^II3 are bonded as an atom constituting the ring skeleton. Examples of the hetero atom include a sulfur atom, an oxygen atom, and a nitrogen atom. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

  The bond of the group represented by the formula (II-1) and the group represented by the formula (II-2) is preferably bonded to a vinyl group, an acrylic group, a methacryl group, an alkanoyl group, or the like.

The structural unit containing a group represented by the formula (II-1) is preferably a structural unit represented by the following formula (II-1-1).
[In the formula (II-1-1),
R ^II1 , R ^II2 , R ^II3 , A ^II1 and A ⁻ represent the same meaning as described above.
R ^II4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ]
In Formula (II-1-1), A ^II1 represents a single bond, a linear or branched aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or carbon. The aromatic hydrocarbon group of Formula 6 to 36 or a combination thereof, and the methylene group contained therein may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. More preferably, it is a single bond, a linear or branched aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 24 carbon atoms, and more preferably a single bond or carbon number. A linear or branched aliphatic hydrocarbon group having 1 to 8 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms. The methylene group contained therein may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group.
R ^II4 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a methyl group.

Examples of the structural unit containing a cation in formula (II-1-1) include the structural units represented below.

In formula (II-1), A ⁻ is a counter anion. Examples of the counter anion of A ⁻ include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. A ^- counter anion represented by a sulfonate anion are preferable, and more preferably an anion of the formula (I-A).
[In the formula (IA),
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced with —O—, —SO ₂ — or —CO—.
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro group. A hexyl group etc. are mentioned.
Q ¹ and Q ² are each independently preferably a fluorine atom or a trifluoromethyl group, and both Q ¹ and Q ² are more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. It may be a group formed by combining two or more of the groups.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , 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 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- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 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 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, adamantane-2,6-diyl group, etc. Groups and the like.

The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— is represented by any one of formulas (b1-1) to (b1-3). Group to be used. In the formulas (b1-1) to (b1-3), * represents a bond with -Y.

In 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 —O— or —CO—.
However, the total number of carbon atoms 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, —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total carbon number of L ^b6 and L ^b7 is 23 or less.

In the formulas (b1-1) to (b1-3), when —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO—, the number of carbons before the replacement is The carbon number of the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include the same divalent saturated hydrocarbon groups as those represented by L ^b1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a C 1-8 divalent saturated hydrocarbon group, 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 In the saturated hydrocarbon group, —CH ₂ — may be replaced by —O— or —CO—.

As the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced by —O— or —CO—, a group represented by the formula (b1-1) or the formula (b1-3) Is preferred.

Examples of formula (b1-1) include groups represented by formula (b1-4) to formula (b1-8). In formula (b1-4) to formula (b1-8), * represents a bond with -Y.
In 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 ^C 1-20 divalent saturated hydrocarbon group, 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 C 1-18 divalent saturated hydrocarbon group, 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 a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 preferably represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 preferably represents a ^C 1-6 divalent saturated hydrocarbon group.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, 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), respectively. In formula (b1-9) to formula (b1-11), * represents a bond with -Y.
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. . —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted 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. . —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted 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. . —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, L ^b24, the total number of carbon atoms of L ^b25 and L ^b26 is 21 or less.

  In formulas (b1-10) and (b1-11), when a hydrogen atom contained in a divalent saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms in the acyloxy group, the ester bond Including the number of CO and O, the carbon number of the saturated hydrocarbon group.

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, and a hydroxycyclohexylcarbonyloxy group.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-4) include the following. * Represents a bond with -Y.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-5) include the following. * Represents a bond with -Y.

Of the groups represented by formula (b1-1), examples of the group represented by formula (b1-6) include the following. * Represents a bond with -Y.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-7) include the following. * Represents a bond with -Y.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-8) include the following. * Represents a bond with -Y.

Examples of the group represented by the formula (b1-2) include the following. * Represents a bond with -Y.

Of the groups represented by formula (b1-3), examples of the group represented by formula (b1-9) include the following. * Represents a bond with -Y.

Of the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-10) include the following. * Represents a bond with -Y.

Of the groups represented by formula (b1-3), examples of the group represented by formula (b1-11) include the following. * Represents a bond with -Y.

Examples of the alkyl group for Y 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, heptyl group, 2 -An alkyl group such as an ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group, and preferably an alkyl group having 1 to 6 carbon atoms. .
Examples of the alicyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— include groups represented by formulas (Y12) to (Y27). Can be mentioned.

  Preferably, it is a group represented by any one of formulas (Y1) to (Y19), more preferably a group represented by formula (Y11), formula (Y14), formula (Y15), or formula (Y19). And more preferably a group represented by the formula (Y11) or the formula (Y14).

As the substituent for the alkyl group of Y, a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, or — (CH ₂ ). _en —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms) Ja represents an integer of 0 to 4).
Examples of the substituent for the alicyclic hydrocarbon group of Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and an alicyclic group having 3 to 16 carbon atoms. A hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or — (CH _{2) niv} in ^{'-O-CO-R b1'} group (wherein, R ^{b1 'is} an alkyl group having 1 to 16 carbon atoms, 3 to 16 carbon atoms alicyclic hydrocarbon group or having 6 to 18 carbon atoms Represents an aromatic hydrocarbon group, and ja ′ represents an integer of 0 to 4).

Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl; tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following. In the following groups, * is a bond to L ^b1 .

In the case where Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y. The group —CH ₂ — is preferably replaced by —O— or —CO—. In this case, —CH ₂ — contained in the alkyl group of Y is not replaced with —O— or —CO—. Even when the hydrogen atom contained in the alkyl group of Y and / or the divalent linear or branched saturated hydrocarbon group of L ^b1 is substituted with a substituent, —CH ₂ — contained in the alkyl group of Y is , -O- or -CO-.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably an adamantyl group which may have a substituent, and constitutes these groups The —CH ₂ — may be replaced by —O—, —SO ₂ — or —CO—. Y is particularly preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

Examples of the anion represented by the formula (IA) include the formulas (IA-1) to (IA-31). Anions represented by formula (IA-1) to formula (IA-29) [hereinafter referred to as “anions (IA-1)” or the like depending on the formula number, etc.). Are preferred, formula (IA-1) to formula (IA-4), formula (IA-9), formula (IA-10), formula (IA-24) to formula The anion represented by any of (IA-29) is more preferable. R ^{i2 to} R ⁱ⁴ in formula (IA-1) to formula (IA-29) each independently represent an alkyl group having 1 to 4 carbon atoms, preferably a methyl group. L ⁴⁰ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.

As the anion represented by the formula (IA), the anions represented by the formula (Ia-1) to the formula (Ia-11) are more preferable, respectively, and the formula (Ia-1) to the formula (Ia-3) And an anion represented by any one of formulas (Ia-7) to (Ia-11) is particularly preferable.

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

Examples of the structural unit (II-1) include the structural units represented below.

In the group represented by the formula (II-2), RA ^- Examples of the organic group containing anion, and an organic group containing a sulfonic acid anion, sulfonyl imide anion, methide anions and anions such as carboxylic acid anion .
The linking group for A ^II2 is preferably a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and the hydrogen atom contained in the hydrocarbon group is a fluorine atom or a perfluoro having 1 to 6 carbon atoms. It is preferably substituted with an alkyl group. The methylene group contained in the hydrocarbon group may be substituted with an oxygen atom, a carbonyl group or a sulfonyl group.
RA ^- organic group containing an anion of is preferably a sulfonic acid anion.

The structural unit containing a group represented by formula (II-2) is preferably a structural unit represented by formula (II-2-A ′).
[In the formula (II-2-A ′)
X ¹ represents a divalent straight chain or branched saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group. In addition, the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group.
R ³ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A ^x1 represents a linear or branched alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group is substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. May be.
RA ⁻ represents an organic group containing an anion.
Z ^{a +} represents an organic cation. ]
A ^x1 is preferably a linear alkanediyl group having 1 to 8 carbon atoms substituted with a C 1-6 perfluoroalkyl group.

The structural unit containing a group represented by the formula (II-2-A ′) is preferably a structural unit represented by the formula (II-2-A).
[In the formula (II-2-A),
R ³ , X ¹ and Z ^{a +} represent the same meaning as described above.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group, and when z is 2 or more, the plurality of R ¹ and R ² are the same or different from each other.
z represents an integer of 0 to 6. ]

As the perfluoroalkyl group for Q ^a , Q ^b , R ¹ and R ² , a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group , Perfluoropentyl group, perfluorohexyl group and the like.

Examples of the halogen atom for R ³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group for R ³ 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, and an n-hexyl group. .
Examples of the alkyl group optionally having a halogen atom for R ³ include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a 1,1,1-trifluoroethyl group, and a 2,2-difluoroethyl group. Etc.

As the divalent linear or branched saturated hydrocarbon group for X ¹ , a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic hydrocarbon group 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 , Linear alkanediyl groups such as dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group Branched alkanediyl groups such as pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 , 4-diyl group, Cycloalkanediyl group such as looctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group Bivalent polycyclic alicyclic saturated hydrocarbon groups and the like.

As what the methylene group contained in the said saturated hydrocarbon group replaced with the oxygen atom, the sulfur atom, or the carbonyl group, the bivalent group represented by a formula (X1)-a formula (X53) is mentioned, for example. However, in these groups, the number of carbon atoms before the methylene group is replaced with an oxygen atom, a sulfur atom or a carbonyl group is 16 or less. In the following formula, * represents a bond with C (R ¹ ) (R ² ).

X ³ represents a divalent hydrocarbon group having 1 to 15 carbon atoms.
X ⁴ represents a divalent hydrocarbon group having 1 to 14 carbon atoms.
X ⁵ represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
X ⁶ represents an alkyl group having 1 to 13 carbon atoms.
X ⁷ represents a trivalent hydrocarbon group having 1 to 13 carbon atoms.
X ⁸ represents a divalent hydrocarbon group having 1 to 12 carbon atoms.

As the structural unit represented by the formula (II-2-A), a structural unit represented by the formula (II-2-A-1) is preferable.
[In the formula (II-2-A-1)
R ¹ , R ² , R ³ , Q ^a , Q ^b , z and Z ^{a +} represent the same meaning as described above.
R ⁴ represents a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms.
X ² represents a C 1-11 divalent linear or branched saturated hydrocarbon group, and the methylene group contained in the saturated hydrocarbon group may be replaced by an oxygen atom, a sulfur atom or a carbonyl group. The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

Examples of the linear or branched saturated hydrocarbon group include a linear or branched alkyl group.
Examples of the divalent linear or branched saturated hydrocarbon group include an alkanediyl group having 1 to 11 carbon atoms. Examples in which the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom, a sulfur atom or a carbonyl group include the same groups as those represented by the above formulas (X1) to (X53).

As the structural unit represented by the formula (II-2-A), a structural unit represented by the formula (II-2-A-2) is more preferable.
[In the formula (II-2-A-2),
R ³ , R ⁴ and Z ^{a +} represent the same meaning as described above.
m and n each independently represent 1 or 2. ]

Examples of the structural unit represented by the formula (II-2-A-1) include the following structural units and the structural units described in International Publication No. 2012/050015. Z ^{a +} represents an organic cation.

Examples of the structural unit represented by the formula (II-2-A-2) include the following structural units. Z ^{a +} represents the same meaning as described above.

In formula (II-2-A), Z ^{a +} represents an organic cation. Examples of organic cations include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, organic benzothiazolium cations, and organic phosphonium cations. Among them, organic sulfonium cations and organic iodonium cations are preferable, and arylsulfonium cations. Cations are more preferred.

Z ^{a + in} formula (II-2-A) is a cation represented by any one of formula (b2-1) to formula (b2-4) (hereinafter referred to as “cation (b2-1) according to the formula number”). ) "Etc.)) is preferred.

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represents 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. The hydrogen atom contained in the alicyclic hydrocarbon group may be 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 bonded, and the -methylene group contained in the ring may be replaced by 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 each independently represent an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7 may be the same or different, and when n2 is 2 or more, the 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 together may form a ring containing a sulfur atom to which they are bonded, and the methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group. .
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 is included in the aliphatic hydrocarbon The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is an alkoxy group having 1 to 12 carbon atoms or 1 to 1 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may together form a ring containing —CH—CO— to which they are bonded, and the methylene group contained in the ring is bonded to 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 ^b11 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, multiple R ^b13 are the same or different, when p2 is 2 or more, multiple R ^b14 are the same or different, and when q2 is 2 or more, multiple R ^b15 are the same or different , When r2 is 2 or more, a plurality of R ^b16 are the same or different, when s2 is 2 or more, a plurality of R ^b17 are the same or different, and when t2 is 2 or more, a plurality of R ^b18 are the same or different Different.

Examples of the aliphatic hydrocarbon 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, and n-octyl group. Group and an alkyl group of 2-ethylhexyl group. In particular, the aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclo group. Examples thereof include cycloalkyl groups such as heptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 3 to 18 carbon atoms, 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 a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. Groups and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

As 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 , Aryl groups such as a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms Groups are preferred.
Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

Alkoxy groups include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-decyloxy and Examples include n-dodecyloxy group.
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.
Examples of the alkylcarbonyloxy group include 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 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 combining R ^b4 and R ^b5 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. . Examples of the ring include a ring having 3 to 18 carbon atoms, and a ring having 4 to 18 carbon atoms is preferable. Moreover, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, and preferably a 3-membered ring to a 7-membered ring. The following rings are mentioned.

The ring formed by combining R ^b9 and R ^b10 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
The ring formed by ^combining R ^b11 and R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Among the cation (b2-1) to cation (b2-4), the cation (b2-1) is preferable.

Examples of the cation (b2-1) include the following cations.

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

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

  When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol% with respect to the total structural units of the resin (A). Preferably it is 2-15 mol%, More preferably, it is 3-10 mol%.

<Structural unit (a)>
The resin (A) may contain a structural unit having an acid labile group other than the structural unit (a1-1) and the structural unit (a1-2) (hereinafter sometimes referred to as “structural unit (a)”). Good. Here, the acid labile group means a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid.

The structural unit (a) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a)”). Examples of the acid labile group contained in the structural unit (a) include a group represented by the following formula (1) and a group represented by the formula (2).
[In the formula (1), R ^{a1 to} R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination of these, or R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
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. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocyclic ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and are included in the hydrocarbon group and the divalent heterocyclic ring. more -CH ₂ - may be replaced by -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 for R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.
Examples of the group that combines an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a methyladamantyl group, a cyclohexylmethyl group, an adamantylmethyl group, and a norbornylethyl group. Etc.
na is preferably 0.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) when R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 are alkyl groups in the formula (1), preferably a tert-butoxycarbonyl group), 2- An alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantane- 1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

  In the group represented by the formula (1), when na is 1, the bond * is preferably bonded to the oxygen atom of the structural unit (Ia) via an alkanediyl group having 1 to 6 carbon atoms. The methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.

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 alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

^{Examples of the} divalent heterocyclic group formed together with the carbon atom and X to which R ^{a2 ′} and R ^{a3 ′} are bonded to each other 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.

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

  In the resin (A), the content of the structural unit (a) is preferably 30 to 98 mol%, more preferably 35 to 90 mol%, based on all the structural units of the resin (A). Preferably it is 40-80 mol%.

<Structural unit (a1-0)>
In addition to the structural unit (a1-1) and the structural unit (a1-2), the structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) is preferably the formula (a1- And a structural unit represented by 0). These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-0) may be referred to as the structural unit (a1-0) and the monomer that derives the structural unit (a1-0) may be referred to as a monomer (a1-0). is there.

[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 to 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 combination thereof. ]

L ^a01 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, more preferably 1.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , the alicyclic hydrocarbon group, and a group obtained by combining these include the same groups as those described for R ^{a1 to} R ^a3 in formula (1).
The alkyl group for R ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group ^{represented by} R ^a02 , R ^a03 and R ^a04 preferably has 8 or less carbon atoms, more preferably 6 or less.
The group combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less, combining the alkyl group and the alicyclic hydrocarbon group. 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, 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.

As the monomer (a1-0), for example, a monomer represented by any one of the formulas (a1-0-1) to (a1-0-12) is preferable, and the formula (a1-0-1) to the formula ( A monomer represented by any one of a1-0-10) is more preferable.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a01 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a1-0).

  The content of the structural unit (a1-0) is preferably 3 to 60 mol% and more preferably 4 to 55 mol% with respect to all the structural units of the resin (A).

<Structural unit (a1-3)>
Furthermore, examples of the structural unit (a1) having the group (1) include 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). Moreover, the monomer which derives the structural unit (a1-3) may be referred to as a monomer (a1-3).
In formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, 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 a combination thereof, the aliphatic hydrocarbon group and the 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— or -CO- may be substituted.
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 ^a10 and R ^a11 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.

Here, -COOR ^a13 includes a group 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 of R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ^a13 include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n -Hexyl group, n-heptyl group, 2-ethylhexyl group, n-octyl group, etc. are mentioned.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^a13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3- Yl group and 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group represented by R ^{a10 to} R ^a12 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, Examples include n-heptyl group, 2-ethylhexyl group, n-octyl group and the like.
The alicyclic hydrocarbon group for R ^{a10 to} R ^a12 may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
-C (R ^a10 ) (R ^a11 ) (R ^a12 ) 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, Groups are preferred.

  Specific examples of the monomer (a1-3) include 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 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-methyl 5-norbornene-2-carboxylate Chill, and the like.

  Since the resin (A) containing the structural unit (a1-3) includes a sterically bulky structural unit, the resist composition of the present invention containing such a resin (A) is more expensive. A resist pattern can be obtained with resolution. Further, since a rigid norbornane ring is introduced into the main chain, the resulting resist pattern tends to be excellent in dry etching resistance.

  When the resin (A) contains the structural unit (a1-3), the content thereof is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A). 20-85 mol% is more preferable.

As the structural unit (a) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter sometimes 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 an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 may represent a hydrocarbon group having 1 to 20 carbon atoms, R ^a35 and R ^a36 are bonded to each other And C—O to which they are bonded to form a divalent heterocyclic ring having 3 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocyclic ring is —O— or — It may be replaced by S-. ]

^Examples of the alkyl group for R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom for R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
The R ^a34 and R ^a35, include the same groups as R ^{a1 'and} R ^a2' of formula (2).
^Ra36 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, or a group formed by combining these. It is done.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, 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. It is a group to be formed, 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 in R ^a36 and the alicyclic hydrocarbon group are preferably unsubstituted. When the aromatic hydrocarbon group in R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

As a monomer which introduce | transduces structural unit (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, monomers represented by formula (a1-4-1) to formula (a1-4-8) are preferable, and formula (a1-4-1) to formula (a1-4-5) and formula (a1- The monomers represented by 4-8) are more preferable.

  When the resin (A) has the structural unit (a1-4), the content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A). 20 to 85 mol% is more preferable.

As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”) Is also included).
In formula (a1-5),
R ^a8 represents a C 1-6 alkyl group optionally having 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 to L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3.

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

As a monomer which introduce | transduces structural unit (a1-5), the monomer described in Unexamined-Japanese-Patent No. 2010-61117 is mentioned, for example. Among these, monomers represented by formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by formula (a1-5-1) or formula (a1-5-2) are preferable. Is more preferable.

  When resin (A) has a structural unit (a1-5), the content rate is preferable 1-50 mol% with respect to all the structural units of resin (A), and 3-45 mol% is more preferable. 5 to 40 mol% is more preferable.

<Structural unit (s)>
The resin (A) may contain a structural unit having no acid labile group other than those described above (hereinafter sometimes referred to as “structural unit (s)”).

The monomer that leads the structural unit (s) is not particularly limited as long as it is a monomer that does not have an acid labile group other than the monomer that leads the structural unit (II) and the structural unit (a2-A). Can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) is an alcoholic hydroxy group.
The structural unit (a2-1) is preferably used as the structural unit (a2). As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

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 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 the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the structural unit (a2-1) having an alcoholic hydroxy group include structural units represented by any of the following formulas (a2-1-1) to (a2-1-6).
A structural unit represented by any of formula (a2-1-1) to formula (a2-1-4) is preferred, and is represented by formula (a2-1-1) or formula (a2-1-3). A structural unit is more preferable.
Examples of the monomer for deriving the structural unit (a2) having an alcoholic hydroxy group include monomers described in JP2010-204646A.

  When the resin (A) contains a structural unit (a2) having an alcoholic hydroxy group, the content is usually 1 to 45 mol%, preferably 1 to 45 mol% with respect to all the structural units of the resin (A). It is 40 mol%, More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But you can. Preferably, a γ-butyrolactone ring or a bridged ring containing a γ-butyrolactone ring structure is used. The structural unit (a3) may contain two or more kinds. Examples of the structural unit (a3) include the following structural units.

As monomers for deriving the structural unit (a3), monomers described in JP 2010-204646 A, monomers described in JP 2000-122294 A, monomers described in JP 2012-41274 A are listed. 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 a structural unit represented by any one of the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-6), the formula (a3-1-1), The structural unit represented by any one of the formula (a3-1-2) and the formula (a3-2-3) to the formula (a3-2-4) is more preferable, and the formula (a3-1-1) or the formula ( The structural unit represented by a3-2-3) is more preferable.
When the resin (A) includes the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). More preferably, it is 10-60 mol%.

<Other structural units (t)>
The resin (A) may contain another structural unit (t) as a structural unit other than the structural unit (I), the structural unit (II), the structural unit (a), and the structural unit (s). As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit having a fluorine atom (hereinafter sometimes referred to as “structural unit (a4)”) and a non-leaving hydrocarbon group. Structural unit (s) (hereinafter sometimes referred to as “structural unit (a5)”), structural unit derived from a carboxy group-containing monomer such as acrylic acid or methacrylic acid, structural unit derived from styrene, derived from alkoxystyrene Examples include structural units, structural units derived from acyloxystyrene, and structural units well known in the art.

The structural unit derived from the alkoxystyrene is a structural unit in which the hydroxy group of the structural unit (a2-0) is substituted with an alkoxy group. Monomers that lead to the structural unit include methoxystyrene, ethoxystyrene, isopropoxystyrene, and tert-butoxystyrene.
The structural unit derived from the acyloxystyrene is a structural unit in which the hydroxy group of the structural unit (a2-0) is substituted with an acyloxy group. Examples of the monomer for deriving the structural unit include benzoyloxystyrene, acetyloxystyrene, and pivaloyloxystyrene.

<Structural unit (a4)>
Examples of the structural unit (a4) include a structural unit represented by the formula (a4-0) (hereinafter may be referred to as “structural unit (a4-0)”).
[In the formula (a4-0),
R ⁷ represents a hydrogen atom or a methyl group.
L ⁴ represents an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

As the perfluoroalkanediyl group of L ³ , a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluorobutane-1,4 -Diyl group, perfluoropentane-1,5-diyl group, perfluorohexane-1,6-diyl group, perfluoroheptane-1,7-diyl group and perfluorooctane-1,8-diyl group.

L ⁴ is preferably a methylene group or an ethylene group, and more preferably a methylene group.
L ³ is preferably a C 1-6 perfluoroalkanediyl group, more preferably a C 1-3 perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include the structural units shown below and structural units in which a methyl group corresponding to R ⁷ in the following structural units is replaced with a hydrogen atom.

As the structural unit (a4), a structural unit represented by formula (a4-1) can be given.
[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents an ^optionally substituted hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—. Good.
However, at least one of A ^a41 and R ^a42 is a group having a halogen atom as a substituent.
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 ^optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents a single bond or a ^C1-C5 aliphatic hydrocarbon group 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. ]
* Is a bond with —O—CO—R ^a42 . ]

^Examples of the halogen atom for A ^a41 and R ^a42 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and preferably a fluorine atom.
The aliphatic hydrocarbon group for A ^a43 may have a carbon-carbon unsaturated bond, but is preferably an aliphatic saturated hydrocarbon group. 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. Examples thereof include aliphatic hydrocarbon groups that are formed.

^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of chain aliphatic hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, hexyldecyl , Heptadecyl group and octadecyl group. Cyclic aliphatic hydrocarbon groups 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 a cyclic aliphatic saturated hydrocarbon group and a group formed by combining these are more preferable.
R ^a42 includes a halogen atom or a group represented by the formula (a-g3) as a substituent, preferably an aliphatic hydrocarbon group which may have a halogen atom, an alkyl group having a halogen atom, and / or Or the aliphatic hydrocarbon group which has group represented by a formula (a-g3) is more preferable.
[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents a C ^3-17 aliphatic hydrocarbon group having at least one halogen atom.
* Represents a bond with a carbonyl group. ]
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and still more preferably a carbon number. It is a 1-6 perfluoroalkyl group, Most preferably, it is a C1-C3 perfluoroalkyl group. 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.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), including the carbon number contained in the group represented by the formula (a-g3), the aliphatic hydrocarbon The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably 1.

The aliphatic hydrocarbon having a group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).
[In the formula (a-g2),
A ^a46 represents an aliphatic hydrocarbon group having 3 to 15 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 3 to 15 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 a carbonyl group. ]

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

A more preferred structure of the partial structure represented by * -A ^a46 -X ^a44 -A ^a47 (* is a bond to a carbonyl group) is the following structure.

^As the alkanediyl group of ^Aa41 , 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 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 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 still more preferably an ethylene group.

In the group represented by the formula (a-g1) of A ^a41 (hereinafter sometimes referred to as “group (a-g1)”), A ^a44 is ^bonded to —O—CO—R ^a42 .
As the aliphatic hydrocarbon group for A ^a42 , A ^a43 and A ^{a44 in} the group (a-g1), a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane- Examples include 1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group and the like. Examples of these substituents include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

^Examples of the group ( ^{ag1) 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—R ^a42 .

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 C 1-10 hydrocarbon group having a fluorine atom. ]

As the alkanediyl group of A ^f1 , 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 straight-chain 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 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 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 chain, a cyclic group, and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
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 -An ethylhexyl group is mentioned.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and cyclodecyl group. A cycloalkyl group is mentioned. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, A methyl norbornyl group and an isobornyl group are mentioned.

Examples of the hydrocarbon group having a fluorine atom for 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 a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 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, 1,1,2,2,3,3,4,4,5,5-decafluoro Pentyl 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 fluorinated alkyl group such as a 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.

A ^f1 in formula (a4-2) is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.
R ^f2 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

[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 having 1 to 17 carbon atoms which may have a fluorine atom. However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

^Examples of the alkanediyl group for A ^f11 include the same groups as the alkanediyl group for A ^f1 .

The aliphatic hydrocarbon group for A ^f13 includes chain and cyclic aliphatic hydrocarbon groups, and divalent aliphatic hydrocarbon groups formed by combining them. The aliphatic hydrocarbon 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.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene Groups, perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic divalent 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, a perfluoroadamantanediyl group, and the like.

As the aliphatic hydrocarbon group for A ^f14 , one of chain and cyclic groups and an aliphatic hydrocarbon group formed by combining them are included. The aliphatic hydrocarbon 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 a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 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, A heptyl group, a perfluoro heptyl group, an octyl group, a perfluorooctyl group, etc. are mentioned.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be 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, and a perfluoroadamantylmethyl group.

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

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

Examples of the structural unit (a4) include 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 represents — (CH ₂ ) _j1 —, — (CH ₂ ) _j2 —O— (CH ₂ ) _j3 — or — (CH ₂ ) _j4 —CO—O— (CH ₂ ) _j5 —.
j1 to j5 each independently represents 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 hydrocarbon groups as R ^f2 in 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, more preferably a C 1-10 alkyl group having a fluorine atom. Preferably, the C1-C6 alkyl group which has a fluorine atom is further more preferable.

In formula (a4-4), A ^f21 is preferably — (CH ₂ ) _j1 —, more preferably an ethylene group or a methylene group, and still more preferably a methylene group.

Examples of the monomer for deriving the structural unit represented by the formula (a4-4) include the following monomers.

  When the resin (A) has a structural unit (a4), the content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on all structural units of the resin (A). More preferably, it is 10 mol%.

<Structural unit (a5)>
The non-elimination hydrocarbon group that the structural unit (a5) has is represented by the following.
[In the formula (a5),
R ⁷ represents a hydrogen atom or a methyl group.
R ⁸ 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 or hydroxy group having 1 to 8 carbon atoms. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ¹ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ¹ represents a single bond or a C 1-18 divalent saturated hydrocarbon group, 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 ⁸ may be monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic aliphatic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, An octyl group and 2-ethylhexyl group are mentioned.
Examples of R ² having a substituent include a 3-hydroxyadamantyl group and a 3-methyladamantyl group.
R ⁸ 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 ¹ include an aliphatic saturated hydrocarbon group and an alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable. Specific examples include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group for L ¹ may be 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 non-leaving hydrocarbon group that the structural unit (a5) has include a linear, branched, or cyclic hydrocarbon group. Especially, it is preferable that a structural unit (a5) has an alicyclic hydrocarbon group. Examples of the structural unit (a5) include the following structural units.

  When the resin (A) has the structural unit (a5), the content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on all structural units of the resin (A). More preferred is ˜15 mol%.

  When resin (A) contains another structural unit (t), 1-50 mol% is preferable with respect to all the structural units of resin (A), and 3-30 mol% is more preferable.

The resin (A) is preferably a resin composed of the structural unit (a) and the structural unit (s).
The structural unit (a) 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), more preferably the structural unit (a1- 1).
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 the structural unit (a2-1). The structural unit (a3) is preferably at least one of the structural unit (a3-1-1) to the structural unit (a3-1-4) and the structural unit (a3-2-1) to the structural unit (a3-2-4). It is a kind.

  The resin (A) preferably contains 15 mol% or more of structural units derived from the monomer having an adamantyl group (particularly the structural unit (a1-1)) with respect to the total structural units (a). When the content of the structural unit having an adamantyl group is large, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

<Resist composition>
The resist composition of the present invention preferably contains at least the resin (A) and further contains an acid generator known in the resist field (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as “quencher (C)”), and may contain a solvent (hereinafter sometimes referred to as “solvent (E)”). preferable.
The resist composition of the present invention preferably further contains a salt with weak acidity such as a weak acid inner salt (hereinafter sometimes referred to as “weak acid inner salt (D)”).

<Resin (A)>
In the resist composition of the present invention, the content of the resin (A) is preferably 80% by mass or more and 99.9% by mass or less in the solid content of the resist composition. In the present specification, the “solid content of the composition” means the total of the components of the resist composition excluding the solvent (E) described later from the resist composition of the present invention. The solid content and the content of the resin (A) relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A) described above. Such a resin may be any resin that does not have the structural unit (I). For example, a structural unit derived from the acid-labile monomer (a1) described above, a structural unit derived from a monomer having an acid-stable group, It may contain a resin having at least one selected from structural units derived from known monomers used in the field, or a resin consisting only of the structural unit (a) and the structural unit (s) (hereinafter referred to as “ Resin (A1) ”), a resin having the structural unit (a4) (hereinafter also referred to as“ resin (X) ”), or a resin composed only of the structural unit (s) may be contained.

As the resin other than the resin (A), the resin (A1) is preferable. In the resin (A1), the content of the structural unit (a) is preferably 1 to 80 mol%, more preferably 1 to 75 mol%, and more preferably 3 to 70 mol% with respect to all the structural units of the resin (A1). Is more preferable.
The structural unit (a) in the resin (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).
The structural unit (s) in the resin (A1) 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 a structural unit represented by formulas (a3-1-1) to (a3-1-4) and represented by formulas (a3-2-1) to (a3-2-4). Is at least one kind of structural unit.
The weight average molecular weight of the resin (A1) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

As the resin other than the resin (A), the resin (X) is also preferable. In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more, and still more preferably 50 mol% or more with respect to all the structural units of the resin (X). .
Examples of the structural unit that the resin (X) may further include a structural unit derived from the structural unit (a2), the structural unit (a3), and other known monomers.
The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that for the resin (A).

  When the resist composition of this invention contains resin other than resin (A), these content rates are 0.1-20 mass% in solid content of a resist composition, Preferably 0.5-15 mass %, More preferably 1 to 10% by mass.

<Acid generator (B)>
The acid generator is classified into a nonionic type and an ionic type, and any of the acid generators (B) of the resist composition of the present invention may be used. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include ionic acid generators composed of a combination of a known cation and a known anion, and onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) are representative. Is. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  As the acid generator (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, Kaisho 62-153853, JP 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712, etc. The compound which generate | occur | produces an acid by the radiation as described in 1 can be used. Moreover, you may use the compound manufactured by the well-known method.

  Examples of the acid generator (B) include organic sulfonates, preferably a fluorine-containing acid generator, more preferably an acid generator (hereinafter referred to as “acid generator (B1) represented by the formula (B1)”. ) ”.

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a C1-C17 divalent saturated hydrocarbon group which may have a single bond or a substituent, and the methylene group contained in the saturated hydrocarbon group is an oxygen atom or a carbonyl group. It may be replaced.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Zb ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group for Q ^b1 and Q ^b2 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, A perfluorohexyl group etc. are mentioned.
Q ^b1 and Q ^b2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group represented by L ^b1 include alkanediyl groups, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and two or more of these groups. A group similar to the divalent group represented by L ¹ described above may be used.

  Examples of the acid generator (B1) include acid generators described in JP2013-68914A, JP2013-3155A, and JP2013-11905A. Specifically, a salt represented by any one of formulas (B1-1) to (B1-28) can be given. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11) ), Formula (B1-12), formula (B1-13), formula (B1-14), formula (B1-20), formula (B1-21), formula (B1-23), formula (B1-24) , A salt represented by any one of formula (B1-25), formula (B1-26), formula (B1-27) and formula (B1-28) is more preferable.

The content of the acid generator (B1) is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, and substantially the acid content with respect to the total amount of the acid generator (B). More preferably, it is only the generator (B1).
The content of the acid generator (B) is preferably 1.5% by mass or more (more preferably 3% by mass or more), preferably 40% by mass or less (more preferably) with respect to 100 parts by mass of the resin (A). 35% by mass or less). The resist composition of the present invention may contain one kind of acid generator (B) alone, or may contain plural kinds.

<Solvent (E)>
The content of the solvent (E) is 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and 99.9% by mass or less, preferably 99% by mass or less in the resist composition. . The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Solvents (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 pyruvic acid Esters such as ethyl; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

<Quencher (C)>
Examples of the quencher (C) include a salt having a lower acidity than an acid generated from a basic nitrogen-containing organic compound or an acid generator (B). The content of the quencher (C) is 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, based on the solid content of the resist composition.
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

  Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, Rudicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyl Didecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, 2,2′-methylenebisaniline, imidazole, 4- Tyrimidazole, 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, etc., preferably diisopropylaniline, particularly preferably 2,6-diisopropylaniline. .

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

<Slightly acidic salt>
The acidity in a salt having a weaker acidity than the acid generated from the acid generator (B) is represented by an acid dissociation constant (pKa). The salt having a lower acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3 <pKa, preferably -1 <pKa <7. A salt, more preferably a salt of 0 <pKa <5.
Examples of the salt having 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 2012-229206 A: Examples thereof include salts described in JP 2012-6908 A, JP 2012-72109 A, JP 2011-39502 A, and JP 2011-191745 A.

<Weak acid inner salt (D)>
The weak acid inner salt (D) is a compound represented by the formula (D).
[In the formula (D),
R ^D1 and R ^D2 are each independently 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, or 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 represents an integer of 0 to 4, and when m ′ is 2 or more, the plurality of R ^D1 are the same or different, and when n ′ is 2 or more, the plurality of R ^D2 are Same or different. ]

Examples of the hydrocarbon group represented by R ^D1 and R ^D2 in the compound represented by the formula (D) include a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, and Examples include groups formed by combining these.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and nonyl group.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be either saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, and cyclododecyl group, norbornyl group, adamantyl group, 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-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group , Aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the group formed by combining these include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (for example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-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.).

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, and a cyclohexanecarbonyl group.
Examples of the acyloxy group include a group in which an oxy group (—O—) is bonded to the acyl group.
Examples of the alkoxycarbonyl group include a group 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 each independently represent 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, or 2 to 2 carbon atoms. Preferred are 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.
m ′ and n ′ are each independently preferably an integer of 0 to 2, and more preferably 0. When m ′ is 2 or more, the plurality of R ^D1 are the same or different, and when n ′ is 2 or more, the plurality of R ^D2 are the same or different.

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

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

  The content of the weak acid salt, particularly the weak acid intramolecular salt (D), is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass in the solid content of the resist composition. is there.

<Other ingredients>
The resist composition of the present invention may contain other components (hereinafter sometimes referred to as “other components (F)”) other than the above-described components, if necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises the resin (A) of the present invention and, if necessary, the resin (A1), the resin (X), the acid generator (B), the solvent (E), and the basic compound (C). It can be prepared by mixing a salt with weak acidity such as weak acid inner salt (D) and other component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to the solvent (E), such as a kind, etc. of resin. An appropriate mixing 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 each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) The process of heating the composition layer after exposure, (5) The process of developing the composition layer after a heating is included.

  The resist composition can be applied onto the substrate by a commonly used apparatus such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. Before applying the resist composition, the substrate may be washed, or an antireflection film or the like may be formed on the substrate.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure during drying under reduced pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do. In this specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, exposure is usually performed through a mask corresponding to a required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

  The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents 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.
In the organic developer, the content of the organic solvent 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 still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace 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 developed resist pattern with a rinse solution. The rinsing 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 solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention includes 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, particularly an electron. It is suitable as a resist composition for line (EB) exposure or a resist composition for EUV exposure, and is useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or 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.
Apparatus: 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 molecular peaks using mass spectrometry (LC: Agilent model 1100, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular peak is indicated by “MASS”.

Synthesis Example 1: Synthesis of compound represented by formula (I-1)
After adding 10 parts of the compound represented by the formula (I-1-a), 160 parts of chloroform, 9.89 parts of dimethylaminopyridine and 15.53 parts of the compound represented by the formula (I-1-c), Stir at 23 ° C. for 30 minutes. To the obtained mixture, 11.22 parts of the compound represented by the formula (I-1-b) and 44.89 parts of chloroform were added, followed by stirring at 23 ° C. for 48 hours. The obtained reaction product was charged with 100 parts of a 10% aqueous oxalic acid solution and stirred at 23 ° C. for 30 minutes. The organic layer recovered by standing and separating was charged with 50 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and allowed to stand and separated to wash the organic layer with water. Such washing operation was repeated 8 times. After the collected organic layer was concentrated, 130 parts of n-heptane was added to the concentrated mass, and the mixture was stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to express the formula (I-1). 7.16 parts of compound were obtained.
MS (mass spectrometry): 296.2 (molecular ion peak)

Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below.

  Hereinafter, these monomers are referred to as “monomer (a1-1-1)” according to the formula number.

Example 1 [Synthesis of Resin A1]
As the monomer, monomer (a1-4-2), monomer (I-1), monomer (a1-1-1), monomer (a2-1-1), monomer (a7-1) and monomer (a3-1- 1), and its molar ratio [monomer (a1-4-2): monomer (I-1): monomer (a1-1-1): monomer (a2-1-1): monomer (a7-1): The monomer (a3-1-1)] was mixed at 20: 15: 35: 5: 5: 20, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.1 mol% and 3.3 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, an aqueous p-toluenesulfonic acid solution was added, and the mixture was stirred for about 6 hours, and then separated to recover the organic layer. The recovered organic layer was poured into a methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin A1 (copolymer) having a weight average molecular weight of 6.7 × 10 ^{3 in} a yield of 83%. Obtained. This resin A1 has the following structural units.

Example 2 [Synthesis of Resin A2]
As the monomer, the monomer (I-1), the monomer (a1-1-1), the monomer (a2-1-1), the monomer (a7-1) and the monomer (a3-1-1) are used, and the molar ratio [ Monomer (I-1): Monomer (a1-1-1): Monomer (a2-1-1): Monomer (a7-1): Monomer (a3-1-1)] is 15: 35: 15: 5: The mixture was mixed to 30 and propylene glycol monomethyl ether acetate of 1.5 mass times the total monomer amount was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.1 mol% and 3.3 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A2 (copolymer) having a molecular weight of 6.2 × 10 ³ was obtained in a yield of 68%. This resin A2 has the following structural units.

Example 3 [Synthesis of Resin A3]
As the monomer, the monomer (I-19), the monomer (a1-1-1), the monomer (a2-1-1), the monomer (a7-1) and the monomer (a3-1-1) are used, and the molar ratio [ Monomer (I-19): Monomer (a1-1-1): Monomer (a2-1-1): Monomer (a7-1): Monomer (a3-1-1)] is 15: 35: 15: 5: The mixture was mixed to 30 and propylene glycol monomethyl ether acetate of 1.5 mass times the total monomer amount was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.1 mol% and 3.3 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A3 (copolymer) having a molecular weight of 6.5 × 10 ³ was obtained in a yield of 63%. This resin A3 has the following structural units.

Example 4 [Synthesis of Resin A4]
As the monomer, monomer (I-1), monomer (a1-1-3), monomer (a1-2-11), monomer (a3-2-1), monomer (a7-1) and monomer (II-2- A-1-1) and its molar ratio [monomer (I-1): monomer (a1-1-3): monomer (a1-2-11): monomer (a3-2-1): monomer (a7) -1): monomer (II-2-A-1-1)] is mixed to 10: 35: 15: 30: 30: 5: 5, and 1.5 mass times of methyl monomer is added to the total amount of monomers. It was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane at 10 ° C. to precipitate the resin, and the resin was filtered. The obtained resin was poured again into a large amount of n-heptane / isopropyl alcohol mixed solvent (1/4 weight ratio), repulped, and filtered to obtain a resin A4 having a weight average molecular weight of 5.3 × 10 ³ (co-polymer). Polymer) with a yield of 50%. This resin A4 has the following structural units.

Synthesis Example 1 [Synthesis of Resin AX1]
As the monomer, monomer (a1-4-2), monomer (a7-1), monomer (I-1) and monomer (II-2-X) were used, and the molar ratio thereof [monomer (a1-4-2): Monomer (a7-1): monomer (I-1): monomer (II-2-X)] was mixed so as to be 35: 15: 47: 3, and methyl ethyl ketone 1.5 times the total monomer amount was added. In addition, a solution was obtained. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane at 10 ° C. to precipitate the resin, and the resin was filtered. The obtained resin was again dissolved in methyl ethyl ketone, a p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for about 6 hours, and then separated to recover the organic layer. The collected organic layer was poured into a large amount of n-heptane at 10 ° C. to precipitate the resin, and this resin was filtered. The obtained resin was poured again into a large amount of n-heptane / isopropyl alcohol mixed solvent (1/4 weight ratio) and repulped, followed by filtration to obtain a resin AX1 (co-polymer) having a weight average molecular weight of 4.8 × 10 ^3. Polymer) with a yield of 68%. This resin AX1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin AX2]
Monomer (a1-4-2) and monomer (I-19) are used as monomers and mixed so that the molar ratio [monomer (a1-4-2): monomer (I-19)] is 75:25. Then, 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.8 mol% and 2.4 mol%, respectively, with respect to the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, an aqueous p-toluenesulfonic acid solution was added, and the mixture was stirred for about 6 hours, and then separated to recover the organic layer. The recovered organic layer was poured into a methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin AX2 (copolymer) having a weight average molecular weight of 1.3 × 10 ^{4 in} a yield of 55%. Obtained. This resin AX2 has the following structural units.

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

<Resin>
A1: Resin A1
A2: Resin A2
A3: Resin A3
A4: Resin A4
AX1: Resin AX1
AX2: Resin AX2

<Acid generator (B)>
B1: salt represented by formula (B1-25); synthesized by the method described in JP2011-126869A

<Quencher (C)>
C1: Tetra-n-butylammonium salicylate (Tokyo Chemical Industry Co., Ltd.)
C2: Diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)
C3: synthesized by the method described in JP2011-039502A

<Solvent (E)>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-butyrolactone 5 parts

(Electron beam exposure evaluation of resist composition)
A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 ° C. for 60 seconds. This silicon wafer was spin-coated with a resist composition so that the film thickness of the composition layer was 0.04 μm. Thereafter, the composition layer was formed by pre-baking on a direct hot plate for 60 seconds at the temperature shown in the “PB” column of Table 1. A line-and-space pattern was directly drawn on the composition layer formed on the wafer using an electron beam drawing machine ("HL-800D 50 keV" manufactured by Hitachi, Ltd.) while changing the exposure stepwise. .
After exposure, post exposure baking is performed for 60 seconds on the hot plate at the temperature shown in the “PEB” column of Table 1, and then paddle development is performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution. A resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount at which the line width and space width of the 60 nm line and space pattern were 1: 1 was defined as effective sensitivity.

<Resolution evaluation>
The resist pattern obtained at the effective sensitivity was observed with a scanning electron microscope, and the minimum line width at which the resist pattern was resolved without falling down was defined as the resolution. The results are shown in Table 2.

(EUV exposure evaluation of resist composition)
An 8-inch silicon wafer was treated with hexamethyldisilazane at 90 ° C. for 60 seconds on a direct hot plate. This silicon wafer was spin-coated with a resist composition so that the film thickness of the composition layer was 0.035 μm.
Thereafter, the composition layer was formed by pre-baking on a direct hot plate for 60 seconds at the temperature shown in the “PB” column of Table 1. The wafer on which the composition layer was formed was exposed to a line-and-space pattern using an EUV exposure machine while changing the exposure amount stepwise.
After exposure, post exposure baking is performed for 60 seconds on the hot plate at the temperature shown in the “PEB” column of Table 1, and then paddle development is performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution. A resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount at which the line width and space width of the line and space pattern having a line width of 22 nm were 1: 1 was defined as effective sensitivity.

<Resolution evaluation>
The resist pattern obtained at the effective sensitivity was observed with a scanning electron microscope, and the minimum line width at which the resist pattern was resolved without falling down was defined as the resolution. 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 resolution.

  Since the resist composition of the present invention is excellent in the resolution of the resulting resist pattern, it is suitable for semiconductor microfabrication and is extremely useful industrially.

Claims (7)

Resin containing a structural unit represented by formula (I) and at least one structural unit selected from a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2) .
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group .
R ² and R ³ are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
R ⁴ represents an alkyl group having 1 to 6 carbon atoms.
X ¹ represents a single bond, —CO—O— * or —CO—NR ⁵ — *, * represents a bond to —Ar, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Represents.
X ² represents a single bond, * —O—L ¹ — or * —CO—O—L ² —, * represents a bond to —Ar, and L ¹ and L ² each independently represent carbon The alkanediyl group of number 1-4 is represented.
Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms. ]
[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 to —CO—. Represents 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 obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ] The resin according to claim ^1, wherein X ¹ and X ² are both single bonds. The resin according to claim 1 or 2, further comprising a structural unit represented by the formula (a2-A).
[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an 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.
A ^a50 represents a single bond or ^* —X ^a51 — (A ^a52 —X ^a52 ) _na —, and * represents a bond to the carbon atom to which —R ^a50 is bonded.
A ^a52 each independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent —O—, ^—CO —O— or —O—CO—.
na represents 0 or 1.
mb represents the integer of 0-4. When mb is an integer greater than or equal to 2, several ^Ra51 may mutually be same or different. ]   Furthermore, resin in any one of Claims 1-3 containing the structural unit which decomposes | disassembles by exposure and generate | occur | produces an acid.   A resist composition comprising the resin according to claim 1 and an acid generator.   The resist composition according to claim 5, further comprising a salt having a lower acidity than an acid generated from the acid generator. (1) The process of apply | coating the resist composition of Claim 5 or 6 on a board | substrate,
(2) The process of drying the composition after application | coating and forming 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.