JP2018070596A - Salt, acid generator, resist composition, and method for producing resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a salt capable of producing a resist pattern with good line edge roughness (LER), an acid generator, and a resist composition.SOLUTION: The salt has a group represented by formula (aa1) or a group represented by formula (aa2). [In the formulae, Rand Reach represent a hydrogen atom, a hydroxy group, or a hydrocarbon group which may have a hydroxy group; Xrepresents a hydroxy group or a hydrocarbon group which may have a hydroxy group; Rrepresents a single bond or a divalent hydrocarbon group which may have a hydroxy group; R, Rand Reach represent a hydrogen atom, a hydroxy group, or a hydrocarbon group which may have a hydroxy group, provided that Rand Rmay be bonded to each other to form a divalent alicyclic hydrocarbon group together with a carbon atom to which they are bonded; Xrepresents a single bond or a divalent hydrocarbon group which may have a hydroxy group; and * represents a bond].SELECTED DRAWING: None

Description

  The present invention relates to a salt, an acid generator, a resist composition, and a method for producing a resist pattern.

Patent Document 1 describes a resist composition containing a salt represented by the formula (IX-1), and Patent Document 2 describes a resist composition containing a salt represented by the formula (IX-2). Is described.

JP 2010-039476 A JP 2012-126708 A

  In the resist composition containing the above salt, the line edge roughness (LER) of the obtained resist pattern may not always be satisfied.

The present invention includes the following inventions.
[1] A salt having a group represented by the formula (aa1) or a group represented by the formula (aa2).
[Where:
R ¹ and R ² each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 18 carbon atoms that may have a hydroxy group, and —CH ₂ — contained in the hydrocarbon group. May be replaced by -O- or -CO-.
X ¹ represents a hydroxy group and a hydrocarbon group having 1 to 18 carbon atoms which may have a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is replaced with —O— or —CO—. It may be.
R ³³ represents a C 1-18 divalent hydrocarbon group which may have a single bond or a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. May be replaced.
R ¹¹ , R ²² and R ³ each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 18 carbon atoms which may have a hydroxy group, and R ¹¹ and R ²² are A divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms may be formed together with the carbon atom to which they are bonded, and —CH ₂ — contained in the hydrocarbon group is —O— or — It may be replaced by CO-.
X ¹¹ represents a C 1-18 divalent hydrocarbon group which may have a single bond or a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. May be replaced.
* Represents a bond. ]
[2] An anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) having a group represented by the formula (aa1) or a group represented by the formula (aa2); The salt according to [1], comprising a cation.
[3] An anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) is a group represented by the formula (aa1) or a group represented by the formula (aa2) and a sulfonate. The salt according to [2], which is an anion having
[4] The group represented by formula (aa1) or the anion having a group represented by formula (aa2) and a sulfonate is an anion represented by formula (AA1) or formula (AA2) [3] Salt.
[Wherein R ¹ , R ² , R ³ , R ¹¹ , R ²² , R ³³ , X ¹ and X ¹¹ represent the same meaning as described above.
Q ¹ , Q ² , Q ¹¹ and Q ¹² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Q ³ , Q ⁴ , Q ¹³ and Q ¹⁴ each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group.
m1 and m2 each independently represents an integer of 0 to 6. When m1 is 2 or more, the plurality of Q ³ and Q ⁴ may be the same as or different from each other. When m2 is 2 or more, the plurality of Q ¹³ and Q ¹⁴ may be the same as or different from each other.
X ¹¹¹ represents * 1-CO—O—, * 1-O—CO—, * 1-O—CO—O—, * 1-CO—O—A ¹ —O—, * 1-CO—O—. A ¹ -CO-, * 1-CO-O-A ¹ -CO-O-, * 1-O-CO-O-A ¹ -O-, * 1-O-CO-O-A ¹ -CO- Or * 1-O—CO—O—A ¹ —CO—O—, wherein * 1 is a bond to —C (Q ¹ ) (Q ² ) — or —C (Q ³ ) (Q ⁴ ) —. Represents the place.
X ¹²¹ represents * 2-CO—O—, * 2-O—CO— or * 2-O—CO—O—, and * 2 represents —C (Q ¹¹ ) (Q ¹² ) — or —C This represents the bonding position with (Q ¹³ ) (Q ¹⁴ )-.
A ¹ represents a divalent hydrocarbon group having 1 to 18 carbon atoms. ]
[5] The salt according to any one of [1] to [4], wherein R ³³ is a single bond.
[6] The salt according to any one of [1] to [4], wherein X ¹¹ is a single bond.
[7] An acid generator containing the salt according to any one of [1] to [6].
[8] A resist composition comprising the acid generator according to [7] and a resin having an acid labile group.
[9] The resist composition according to [8], further comprising a salt that generates an acid having a lower acidity than an acid generated from an acid generator.
[10] (1) A step of applying the resist composition according to [8] or [9] 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 method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

  A salt capable of producing a resist pattern having good line edge roughness (LER) is provided.

In the present specification, "(meth) acrylic monomer" means at least one monomer having a "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively. 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. When stereoisomers exist, all stereoisomers are included.
In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition.

[Salt (aa)]
The salt of the present invention is a salt having a group represented by the formula (aa1) or a group represented by the formula (aa2) (hereinafter sometimes referred to as “salt (aa)”).
[Where:
R ¹ and R ² each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 18 carbon atoms that may have a hydroxy group, and —CH ₂ — contained in the hydrocarbon group. May be replaced by -O- or -CO-.
X ¹ represents a hydroxy group and a hydrocarbon group having 1 to 18 carbon atoms which may have a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is replaced with —O— or —CO—. It may be.
R ³³ represents a C 1-18 divalent hydrocarbon group which may have a single bond or a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. May be replaced.
R ¹¹ , R ²² and R ³ each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 18 carbon atoms which may have a hydroxy group, and R ¹¹ and R ²² are A divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms may be formed together with the carbon atom to which they are bonded, and —CH ₂ — contained in the hydrocarbon group is —O— or — It may be replaced by CO-.
X ¹¹ represents a C 1-18 divalent hydrocarbon group which may have a single bond or a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO. -May be substituted.
* Represents a bond. ]

Examples of the hydrocarbon group having 1 to 18 carbon atoms represented by X ¹ , R ¹ , R ² , R ¹¹ , R ²² and R ³ include an alkyl group, a monocyclic or polycyclic saturated alicyclic hydrocarbon A group, an aromatic hydrocarbon group, and the like, and a combination of two or more of these groups may be used.
Examples of the alkyl group having 1 to 18 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group. .
The alicyclic hydrocarbon group having 3 to 18 carbon atoms 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, and a norbornyl group.
Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include a phenyl group and a naphthyl group.
—CH ₂ — contained in the hydrocarbon group having 1 to 18 carbon atoms represented by X ¹ , R ¹ , R ² , R ¹¹ , R ²² and R ³ is replaced by —O— or —CO—. Also good. Examples of the hydrocarbon group replaced by —O— or —CO— include an alkoxy group, an alkylcarbonyl group, an alkylcarbonyloxy group, and a phenoxy group.
As an alkoxy group, C1-C17 alkoxy groups, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentaoxy group, a hexaoxy group, a cyclohexaoxy group, are mentioned.
Examples of the alkylcarbonyl group include C2-C18 alkylcarbonyl groups such as an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include C2-C17 alkylcarbonyloxy groups such as an acetyloxy group, a propionyloxy group, and a butyryloxy group.

Examples of the divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms that are formed together with the carbon atom to which R ¹¹ and R ²² are bonded to each other include the monocyclic and polycyclic alicyclic groups described above. A hydrocarbon group is mentioned. Of these, a cyclohexyl group, an adamantyl group and the like are preferable.

Examples of the divalent hydrocarbon group having 1 to 18 carbon atoms represented by X ¹¹ and R ³³ include alkanediyl group, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and aromatic carbonization. Examples thereof include a hydrogen group, and two or more of these groups may be combined.
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 Linear alkanediyl groups such as
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- 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. Group;
Phenylene group, naphthylene group, anthrylene group, p-methylphenylene group, p-tert-butylphenylene group, p-adamantylphenylene group, tolyl group, xylylene group, cumenylene group, mesitylene group, biphenylene group, phenanthrylene group, 2,6 -Aromatic hydrocarbon groups such as diethylphenylene group and 2-methyl-6-ethylphenylene group.

X ¹¹ is preferably a single bond.
R ³³ is preferably a single bond.
R ¹ and R ² are preferably each independently a hydrogen atom, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms which may have a hydroxy group.
R ¹¹ and R ¹² are each independently an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aromatic hydrocarbon group having 6 to 16 carbon atoms, or R ¹¹ and R ^12. Are preferably bonded together to form an alicyclic hydrocarbon group having 3 to 18 carbon atoms together with the carbon atom to which they are bonded.
X ¹ is preferably a hydroxy group.
R ³ is preferably a hydrogen atom.

The group represented by the formula (aa1) or the group represented by the formula (aa2) may be contained in either a cation or an anion. The salt (aa) is preferably a salt composed of an anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) and a cation, and a group represented by the formula (aa1) or A salt composed of an anion having a group represented by the formula (aa2) and an organic cation (hereinafter sometimes referred to as ZI ⁺ ) is more preferable.

The anion in the salt (aa) is preferably an anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) and a sulfonate.
The anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) is more preferably an anion represented by the formula (AA1) or the formula (AA2).
(In the formula, R ¹ , R ² , R ³ , R ¹¹ , R ²² , R ³³ , X and X ¹¹ represent the same meaning as described above.
Q ¹ , Q ² , Q ¹¹ and Q ¹² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Q ³ , Q ⁴ , Q ¹³ and Q ¹⁴ each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group.
m1 and m2 each independently represents an integer of 0 to 6. When m1 is 2 or more, the plurality of Q ³ and Q ⁴ may be the same as or different from each other. When m2 is 2 or more, the plurality of Q ¹³ and Q ¹⁴ may be the same as or different from each other.
X ¹¹¹ represents * 1-CO—O—, * 1-O—CO—, * 1-O—CO—O—, * 1-CO—O—A ¹ —O—, * 1-CO—O—. A ¹ -CO-, * 1-CO-O-A ¹ -CO-O-, * 1-O-CO-O-A ¹ -O-, * 1-O-CO-O-A ¹ -CO- Or * 1-O—CO—O—A ¹ —CO—O—, wherein * 1 is a bond to —C (Q ¹ ) (Q ² ) — or —C (Q ³ ) (Q ⁴ ) —. Represents the place.
X ¹²¹ represents * 2-CO—O—, * 2-O—CO— or * 2-O—CO—O—, and * 2 represents —C (Q ¹¹ ) (Q ¹² ) — or —C This represents the bonding position with (Q ¹³ ) (Q ¹⁴ )-.
A ¹ represents a divalent hydrocarbon group having 1 to 18 carbon atoms. )

Examples of the perfluoroalkyl group represented by Q ¹ , Q ² , Q ³ , Q ⁴ , Q ¹¹ , Q ¹² , Q ¹³ and Q ¹⁴ include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, Examples thereof include a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group.
Q ¹ , Q ² , Q ¹¹ and Q ¹² are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.
Q ³ , Q ⁴ , Q ¹³ and Q ¹⁴ are each independently preferably a hydrogen atom or a fluorine atom.
Examples of the divalent hydrocarbon group having 1 to 18 carbon atoms represented by A ^1, the same thing can be mentioned divalent hydrocarbon group having 1 to 18 carbon atoms represented by ^{R 33,.} 1 to carbon atoms It is preferably a divalent hydrocarbon group of 8 and more preferably an alkanediyl group having 1 to 8 carbon atoms.
m1 is preferably 0.
m2 is preferably 0.
X ¹¹¹ is preferably * 1-CO—O—A ¹ —O—, * 1-CO—O—A ¹ —CO—, or * 1-O—CO—O—A ¹ —O—.
X ¹²¹ is preferably * 2-CO-O- or * 2-O-CO-O-.

Specific examples of the anion constituting the salt (aa) include the following.

Examples of the organic cation ZI ⁺ in the salt (aa) include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.
Among these, a cation represented by any one of the formulas (b2-1) to (b2-4) (hereinafter may be referred to as “cation (b2-1)” or the like depending on the formula number) is preferable.
[In Formula (b2-1)-Formula (b2-4),
R ^{b4 to} R ^b6 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group which may be substituted is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms or a glycidyloxy group. 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 form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. .
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 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 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. .
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 —CH ₂ — contained in the ring is —O—, —SO—. Alternatively, it may be replaced by -CO-.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When q2 is 2 or more The plurality of R ^b15 may be the same or different. When r2 is 2 or more, the plurality of R ^b16 may be the same or different. When s2 is 2 or more, the plurality of R ^b17 is ^They may be the same or different, and when t2 is 2 or more, the plurality of R ^b18 may be the same or 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, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Of the alkyl group. Among them, the aliphatic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. And cycloalkyl groups such as a cyclooctyl group and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
Among ^them, the number of carbon atoms in the alicyclic hydrocarbon group R ^{b9 to R b12} is preferably 3 to 18, more preferably from 4 to 12.

  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 or the alicyclic hydrocarbon group having 3 to 18 carbon atoms is preferable.
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.

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.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The ring that R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded is any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. There may be. As this ring, a C3-C18 ring is mentioned, Preferably a C4-C18 ring is mentioned. Moreover, as a ring containing a sulfur atom, 3-membered ring-12-membered ring are mentioned, Preferably 3-membered ring-7-membered ring are mentioned, Specifically, the following ring is mentioned.

The ring formed by R ^b9 and R ^b10 together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Good. Examples of the ring include 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) and thian-1-ium ring. Ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by ^combining R ^b11 and R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of the ring include 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. It is done.

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

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

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

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

The salt (aa) is preferably a combination of the above-mentioned anion and organic cation. These anions and cations can be arbitrarily combined.
Specific examples of the salt (aa) are shown in Table 1. In Table 1, for example, the salt (I-1) means a salt composed of an anion represented by the formula (I-a-1) and a cation represented by the formula (b2-c-1). Represents the salt shown.

  Especially, salt (aa) is salt (I-1), salt (I-2), salt (I-3), salt (I-4), salt (I-13), salt (I-14). , Salt (I-15), salt (I-16), salt (I-25), salt (I-26), salt (I-27), salt (I-28), salt (I-37), Salt (I-38), Salt (I-39), Salt (I-40), Salt (I-49), Salt (I-50), Salt (I-51), Salt (I-52), Salt (I-61), salt (I-62), salt (I-63), salt (I-64), salt (I-73), salt (I-74), salt (I-75) and salt ( I-76) is preferred.

<Method for producing salt (aa)>
A salt (I1) consisting of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA1), wherein X ¹¹¹ is —CO—O—, is a salt represented by the formula (I1-a); It can be produced by reacting a compound represented by I1-b) in a solvent.
(Wherein R ¹ , R ² , Q ¹ , Q ² , Q ³ , Q ⁴ , R ³³ , m1 and X ¹ represent the same meaning as described above.
ZI ⁺ represents an organic cation. )
Examples of the solvent include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I1-b) include compounds represented by the following formula, and are easily available from the market.

A compound represented by formula (I1-a) is obtained by reacting a compound represented by formula (I1-c) with a compound represented by formula (I1-d) in a solvent such as acetonitrile. Can be obtained.
(In the formula, all symbols have the same meaning as described above.)
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I1-c) include compounds represented by the following, and can be produced by the method described in JP-A-2008-127367.

A salt (I2) comprising an anion represented by the formula (AA1) and an organic cation (ZI ⁺ ), wherein X ¹¹¹ is —O—CO—, is a compound represented by the formula (I2-b) and carbonyldiimidazole. Can be further reacted with a salt represented by the formula (I2-a).
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the salt represented by the formula (I2-a) include salts represented by the following, and can be produced by the method described in JP2012-193170A.
Examples of the compound represented by the formula (I2-b) include compounds represented by the following formula, and are easily available from the market.

A salt (I3) composed of an anion represented by the formula (AA1) and an organic cation (ZI ⁺ ) in which X ¹¹¹ is —O—CO—O— is a compound represented by the formula (I1-b), It can be produced by reacting with diimidazole in a solvent and further reacting with a salt represented by the formula (I2-a).
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

A salt (I4) composed of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA1), wherein X ¹¹¹ is —CO—O—A ¹ —O— is represented by the formula (I1-a). It can be produced by reacting a salt with a compound represented by the formula (I4-b) in a solvent.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I4-b) include compounds represented by the following formula, and are easily available from the market.

A salt (I5) consisting of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA1), wherein X ¹¹¹ is —CO—O—A ¹ —CO— is represented by the formula (I1-a). It can be produced by reacting a salt with a compound represented by the formula (I5-b) in a solvent.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I5-b) include compounds represented by the following formula, and are easily available from the market.

A salt (I6) composed of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA1) wherein X ¹¹¹ is —CO—O—A ¹ —CO—O— is represented by the formula (I1-a). The salt represented by formula (I6-b) can be produced by reacting in a solvent.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I6-b) include compounds represented by the following formula, and are easily available from the market.

A salt (I7) consisting of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA1) wherein X ¹¹¹ is —O—CO—O—A ¹ —O— is represented by the formula (I4-b). It can manufacture by making it react with the salt represented with Formula (I2-a), after making the compound and carbonyldiimidazole react in a solvent.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

A salt (I8) composed of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA1), wherein X ¹¹¹ is —O—CO—O—A ¹ —CO— is represented by the formula (I5-b). It can manufacture by making it react with the salt represented with Formula (I2-a), after making the compound and carbonyldiimidazole react in a solvent.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

A salt (I9) consisting of an anion represented by the formula (AA1) and an organic cation (ZI ⁺ ) wherein X ¹¹¹ is —O—CO—O—A ¹ —CO—O— is represented by the formula (I6-b): It can manufacture by making it react with the salt represented with a formula (I2-a), after making the compound and carbonyldiimidazole react in a solvent.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

A salt (I10) composed of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA2), wherein X ¹²¹ is —CO—O—, and a salt represented by the formula (I1-a), It can be produced by reacting a compound represented by I10-b) in a solvent.
(Wherein R ¹¹ , R ²² , R ³ , Q ¹¹ , Q ¹² , Q ¹³ , Q ¹⁴ , X ¹¹ , m2 and ZI ⁺ represent the same meaning as described above.
Examples of the solvent include chloroform and acetonitrile.
Examples of the compound represented by the formula (I2-b) include compounds represented by the following formula, and are easily available from the market.

A salt (I11) composed of an anion and an organic cation (ZI ⁺ ) represented by the formula (AA2), wherein X ¹²¹ is —O—CO—, is represented by the formula (I2-a), It can be produced by reacting a compound represented by I11-b) in a solvent.
(Wherein R ¹¹ , R ²² , R ³ , Q ¹¹ , Q ¹² , Q ¹³ , Q ¹⁴ , X ¹¹ , m2 and ZI ⁺ represent the same meaning as described above.
Examples of the solvent include chloroform and acetonitrile.
Examples of the compound represented by the formula (I11-b) include compounds represented by the following formula, and are easily available from the market.

A salt (I12) consisting of an anion represented by formula (AA2) and an organic cation (ZI ⁺ ), wherein X ¹²¹ is —O—CO—O—, is a compound represented by formula (I10-b) and carbonyl It can be produced by reacting with diimidazole in a solvent and further reacting with a salt represented by the formula (I2-a).
(Wherein R ¹¹ , R ²² , R ³ , Q ¹¹ , Q ¹² , Q ¹³ , Q ¹⁴ , X ¹¹ , m2 and ZI ⁺ represent the same meaning as described above.
Examples of the solvent include chloroform and acetonitrile.

[Acid generator containing salt (aa)]
The acid generator of the present invention contains a salt (aa). In the acid generator, the salt (aa) may be used alone or in combination of two or more.
In addition to the salt (aa), the acid generator of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as “acid generator (B)”).
When the acid generator (B) is contained in addition to the salt (aa) as the acid generator, the content ratio of the salt (aa) and the acid generator (B) (mass ratio, salt (aa): acid The generator (B)) is usually 1:99 to 99: 1, preferably 2:98 to 98: 2, more preferably 5:95 to 95: 5.

[Resist composition]
The resist composition of the present invention contains an acid generator containing a salt (aa) and a resin having an acid labile group (hereinafter sometimes referred to as “resin (A)”). 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. To do.
The resist composition may further contain an acid generator (B), a quencher (hereinafter sometimes referred to as “quencher (C)”), and a solvent (hereinafter sometimes referred to as “solvent (E)”). preferable.

<Acid generator (B)>
The acid generator (B) that may be used in combination with the acid generator containing the salt (aa) may be either nonionic or ionic. Nonionic acid generators include organic halides, sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (For example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include ionic acid generators comprising a combination of a known cation and a known anion, and onium salts containing an onium cation (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. And the acid generators described in JP2013-68914A, JP2013-3155A, JP2013-11905A, and the like. Moreover, you may use the acid generator manufactured by the well-known method.

Examples of the acid generator (B) include organic sulfonates, preferably fluorine-containing acid generators, more preferably an acid generator represented by the formula (B1) (hereinafter referred to as “acid generator ( B1) ”may be mentioned).
[In the formula (B1),
Q ^b11 and Q ^b12 each independently represent a fluorine atom or a ^C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—, The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and is included in the alicyclic hydrocarbon group − CH ₂ — may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

^Examples of the perfluoroalkyl group for Q ^b11 and Q ^{b12 include} the same groups as those described for the perfluoroalkyl group represented by Q ¹ and Q ² .
Q ^b11 and Q ^b12 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom. More preferably, both Q ^b11 and Q ^b12 are fluorine atoms.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these 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.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include any of formulas (b1-1) to (b1-3) The group represented by these is mentioned. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with -Y.
[In the formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
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, and the saturated The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms 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, and the saturated The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In Formula (b1-1) to Formula (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbons before the replacement is represented by the carbon number of the saturated hydrocarbon group. It is a number.
Examples of the divalent saturated hydrocarbon group include the same divalent saturated hydrocarbon group of L ^b1.

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.

As the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of 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 the group represented by the formula (b1-1) include the following.

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

Examples of the group represented by the formula (b1-3) include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
When —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO—, the number may be one or two or more. . Examples of such a group include groups represented by formula (Y12) to formula (Y38).

  In Y, two hydrogen atoms contained in the alicyclic hydrocarbon group are each substituted with an oxygen atom, and the two oxygen atoms together with an alkanediyl group having 1 to 8 carbon atoms form a ketal ring. Alternatively, a structure in which oxygen atoms are bonded to different carbon atoms may be included. However, in the case of constituting a spiro ring such as formula (Y28) to formula (Y33), the alkanediyl group between two oxygen atoms preferably has one or more fluorine atoms. Of the alkanediyl groups contained in the ketal structure, those in which the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom are preferred.

  Among them, a group represented by any one of Formula (Y1) to Formula (Y20), Formula (Y30), and Formula (Y31) is preferable, and Formula (Y11), Formula (Y15), and Formula (Y Y16), a formula (Y19), a formula (Y20), a group represented by formula (Y30) or a formula (Y31) may be mentioned, more preferably a formula (Y11), a formula (Y15), a formula (Y20) or a formula. And a group represented by (Y30).

Examples of the substituent of the alicyclic hydrocarbon group represented by 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 3 to 16 carbon atoms. Alicyclic hydrocarbon group, alkoxy group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, glycidyloxy group Or — (CH ₂ ) _ja —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 6 to 18 carbon atoms). 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 Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following.

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 methylene group may be replaced by an oxygen atom, a sulfonyl group or a carbonyl group. Y is more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group, or a group represented by the following.

  The anion in the acid generator (B1) is an anion represented by the formula (B1-A-1) to the formula (B1-A-55) [hereinafter referred to as “anion (B1-A-1) according to the formula number”. And so on. ] Is preferable, Formula (B1-A-1)-Formula (B1-A-4), Formula (B1-A-9), Formula (B1-A-10), Formula (B1-A-24)-Formula (B1-A-33), Formula (B1-A-36) to Formula (B1-A-40), Formula (B1-A-47) to Formula (B1-A-55) An anion is more preferable.

Here, R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group.
R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. It is a group to be formed, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
L ⁴⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ¹ and Q ² represent the same meaning as described above.
Specific examples of the anion in the acid generator (B1) include the anions described in JP-A No. 2010-204646.

Preferable anions in the acid generator (B1) include anions represented by formulas (B1a-1) to (B1a-34), respectively.

  Especially, Formula (B1a-1)-Formula (B1a-3) and Formula (B1a-7)-Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), Formula (B1a-22) ) To (B1a-34) are preferable.

Examples of the organic cation for Z ⁺ include the same organic cation as exemplified for the organic cation ZI ⁺ in the salt (aa).

  Specific examples of the acid generator (B) include salts represented by any one of formulas (B1-1) to (B1-48). Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1) to Formula (B1-3), Formula (B1-5) to Formula (B1-7), Formula (B1-11) to Formula (B1-14) ), Formula (B1-17), Formula (B1-20) to Formula (B1-26), Formula (B1-29), Formula (B1-31) to Formula (B1-48). A salt is more preferred.

The salt (aa) acts as an acid generator in the resist composition.
The content of the salt (aa) is preferably 1 to 40 parts by mass and more preferably 2 to 35 parts by mass with respect to 100 parts by mass of the resin (A).
The acid generator (B) may contain 1 type independently, and may contain 2 or more types.
The content of the acid generator (B) is preferably 1 to 40 parts by mass and more preferably 3 to 35 parts by mass with respect to 100 parts by mass of the resin (A).
In the resist composition, the content of the salt (aa) and the acid generator (B) is preferably 1.5 parts by mass or more (more preferably 3 parts by mass or more) with respect to 100 parts by mass of the resin (A). , Preferably 40 parts by mass or less (more preferably 35 parts by mass or less).

<Resin (A)>
The resin (A) has a structural unit which does not have a halogen atom and has an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). Examples of the structural unit other than the structural unit (a1) include a structural unit having no halogen atom and no acid labile group (hereinafter sometimes referred to as “structural unit (s)”), structural unit (a1), and A structural unit other than the structural unit (s) (hereinafter sometimes referred to as “structural unit (t)”. For example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as “structural unit (a4)”), which will be described later. Examples thereof include a structural unit having a non-leaving hydrocarbon group (hereinafter sometimes referred to as “structural unit (a5)”) and other structural units derived from monomers known in the art.

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

^Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group.
The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 may be 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). Carbon number of the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 is preferably 3 to 16.
Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl An ethyl group etc. are mentioned.
Preferably, ma is 0 and na is 1.
Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where 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 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.
The aromatic hydrocarbon group includes phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
When R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocyclic group together with the carbon atom to which they are bonded and X, —C (R ^{a1 ′} ) (R ^{a3 ′} ) —X—R ^{a2 ′} The following groups may be mentioned as: * Represents a bond.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

The group represented by the formula (1) is a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, ma = 0, na = 1, preferably tert-butoxycarbonyl Group), 2-alkyladamantan-2-yloxycarbonyl group (in formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded are adamantyl groups, R ^a3 is an alkyl group, ma = 0, na = 1 ) And 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups, R ^a3 is an adamantyl group, ma = 0, na = 1), etc. Furthermore, the following groups are mentioned. * Represents a bond.

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

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

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

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

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^a01 , L ^a1 and L ^a2 are preferably an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O— (where k01 is preferably an integer of 1 to 4, more preferably Is 1.), more preferably an oxygen atom.
R ^a02 , R ^a03 , R ^a04 , R ^a6, R ^a7 , the alkyl group, the alicyclic hydrocarbon group, and the combination thereof are the same as those ^exemplified for R ^{a1 to} R ^a3 in formula (1). Groups.
The carbon number of the alkyl group of R ^a02 , R ^a03 and R ^a04 is preferably 1 to 6, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.
The carbon number of the alkyl group represented by R ^a6 and R ^a7 is preferably 6 or less, more preferably 1 to 3, and further preferably 2 or 3.
Carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 is preferably 3-8, more preferably 3-6.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of the alkyl group and the alicyclic hydrocarbon 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.
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 the structural unit (a1-0), for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-12) and a methyl group corresponding to R ^a01 can be a hydrogen atom. The substituted structural unit is mentioned, The structural unit represented by either the formula (a1-0-1)-a formula (a1-0-10) is preferable.

As a monomer which introduce | transduces structural unit (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among them, a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) and a structural unit in which a methyl group corresponding to R ^a4 is replaced with a hydrogen atom are preferable. -1-1)-the structural unit represented by any one of formula (a1-1-4) is more preferable.

As the structural unit (a1-2), the structural unit represented by any one of the formulas (a1-2-1) to (a1-2-6) and the methyl group corresponding to R ^a5 were replaced with hydrogen atoms. Structural units may be mentioned, and formula (a1-2-2) and formula (a1-2-5) are preferred.

  When the resin (A) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (A). It is 10-95 mol% normally with respect to a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

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 any integer of 1 to 3.
s1 ′ represents any integer of 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group and a trifluoromethyl group. Groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
Of L ⁵² and L ⁵³ , one is preferably —O— and the other is preferably —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, structural units each represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and are represented by formula (a1-5-1) or formula (a1-5-2). A structural unit 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.

In addition, examples of the structural unit (a1) include the following structural units.

  When the resin (A) includes any one of the structural unit (a1-3-1) to the structural unit (a1-3-7), the content is 10 to 10% with respect to all the structural units of the resin (A). 95 mol% is preferable, 15-90 mol% is more preferable, 20-85 mol% is further more preferable.

The structural unit having a group represented by the formula (2) in the structural unit (a1) may be referred to as a structural unit represented by the formula (a1-4) (hereinafter referred to as “structural unit (a1-4)”). .).
[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl An oxy group or a methacryloyloxy group is represented.
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 Together with —C—O— to which they are bonded to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group is — O- or -S- may be substituted. ]

^Examples of the alkyl group in R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom in R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. Is mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. Especially, a C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further more preferable.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
As the hydrocarbon group for R ^a34, R ^a35 and R ^a36, an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group, and include groups formed by combining these, alkyl groups and alicyclic hydrocarbon groups Examples thereof include the same groups as the alkyl group and the alicyclic hydrocarbon group in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 .
The aromatic hydrocarbon group includes phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the combined group include a group obtained by combining the above-described alkyl group and alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, and an aryl-cyclohexyl group such as a phenylcyclohexyl group. In particular, as R ^a36 , an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these Is mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
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.
As la, 0 or 1 is preferable, and 0 is more preferable.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group, 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. A group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group for R ^a36 is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

As a structural unit (a1-4), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Preferably, hydrogen atom corresponding to ^{R a32} in equation (a1-4-1) represented respectively to Formula (a1-4-8) structural units and structural units (a1-4) is replaced by a methyl group structure And more preferably, structural units represented by formula (a1-4-1) to formula (a1-4-5), respectively.

When the resin (A) includes 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). 20-85 mol% is more preferable.

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no halogen atom and no acid labile group (hereinafter sometimes referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no halogen atom and no acid labile group, which is known in the resist field, 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. The resin (A) has a hydroxy group and has no structural unit (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring, and has an acid labile. A resin having a structural unit having no group (hereinafter sometimes referred to as “structural unit (a3)”) is preferable.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When producing a resist pattern from the resist composition of the present invention, when the exposure light source is a high energy ray such as KrF excimer laser (248 nm), electron beam or EUV (extreme ultraviolet light), it has a phenolic hydroxy group. It is preferable to use the structural unit (a2). In addition, when the exposure light source is an ArF excimer laser (193 nm) or the like, the structural unit (a2) having an alcoholic hydroxy group is preferable. 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 a phenolic hydroxy group include 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 alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl An oxy group or a methacryloyloxy group is represented.
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 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 an integer of 0 to 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.

^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 alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group, and a butyryl group.
^Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* —X ^a51 — (A ^a52 —X ^a52 ) _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 -. Among these, ^* —CO—O—, ^* —CO—O—A ^a52 —CO—O— or ^* —O—A ^a52 —CO—O— is preferable.

Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -Methylbutane-1,4-diyl group etc. are mentioned.
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.

As the structural unit (a2-A), structural units represented by formula (a2-2-1) to formula (a2-2-8) can be given. The structural unit (a2-A) is represented by the structural unit represented by the formula (a2-2-1), the structural unit represented by the formula (a2-2-1), and the formula (a2-2-5). And a structural unit represented by the formula (a2-2-6).

  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%.

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 any 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 of 1 to 4) More preferably, it 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.

As a structural unit (a2-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. The structural unit represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable.

  When resin (A) contains a structural unit (a2-1), the content rate is 1-45 mol% normally with respect to all the structural units of resin (A), Preferably it is 1-40 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, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure is used.

  The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These 1 type may be contained independently and 2 or more types may be contained.

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

Examples of the aliphatic hydrocarbon group represented by R ^a21 , R ^a22 , R ^a23 and R ^a25 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. An alkyl group is mentioned.
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
^Examples of the alkyl group for R ^a24 include a methyl group, an ethyl group, 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. An alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
Examples of the alkyl group having a halogen atom of Ra ²⁴ include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.

^Examples of the alkanediyl group of L ^a8 and L ^a9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group, etc. are mentioned.

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are independently of each other preferably —O— or k3 is an integer of 1 to 4 * —O— ( A group represented by CH ₂ ) _{k 3} —CO—O—, more preferably —O— and * —O—CH ₂ —CO—O—, and still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are independently of each other preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. It is.
R ^a25 is preferably a carboxy group, a cyano group, or a methyl group.
L ^a7 is preferably —O— or ^* —O—L ^a8 —CO—O—, more preferably —O—, —O—CH ₂ —CO—O— or —O—C ₂ H ₄ —. CO-O-.

In formula (a3-4), formula (a3-4) ′ is particularly preferred.
(Wherein R ^a24 and L ^a7 represent the same meaning as described above.)

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) A structural unit represented by any one of 1) to formula (a3-3-4) and formula (a3-4-1) to formula (a3-4-12) is preferable.

In the structural units represented by the above formulas (a3-4-1) to (a3-4-12), a compound in which the methyl group corresponding to R ^a24 is replaced with a hydrogen atom is also represented by the structural unit (a3-4). ).

When the resin (A) includes the structural unit (a3), the total 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%.
Moreover, the content rate of a structural unit (a3-1), a structural unit (a3-2), a structural unit (a3-3), and a structural unit (a3-4) is respectively with respect to all the structural units of resin (A). 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is more preferable.

<Structural unit (t)>
The resin (A) may contain another structural unit (t) as a structural unit other than the structural unit (a1) and the structural unit (s). Examples of the structural unit (t) include the structural unit (a4) and the structural unit (a5).

<Structural unit (a4)>
As the structural unit (a4), a structural unit represented by formula (a4-0) can be given.
[In the formula (a4-0), R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkyl cycloalkanediyl group perfluoro alkanediyl group or 3 to 12 carbon atoms having 1 to 8 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the divalent aliphatic saturated hydrocarbon group represented by L ⁴ include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, and ethane-1 1,2-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group An alkanediyl group.

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 perfluoropropane-2,2 -Diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluoroheptane-2 2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3, A 3-diyl group, a perfluorooctane-4,4-diyl group, etc. are mentioned.
Examples of the L ³ perfluorocycloalkanediyl group include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

L ⁴ is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or 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 a structural unit in which a methyl group corresponding to R ⁵ in the following structural units is replaced with a hydrogen atom.

Examples of the structural unit (a4) include a structural unit represented by the formula (a4-1).
[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.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.
[In the formula (a-g1), s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a ^C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
A ^a43 represents a ^C1-C5 divalent aliphatic hydrocarbon group which may have a single bond or a substituent.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O— or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* Is a bond, and * on the right side is a bond with —O—CO—R ^a42 . ]

^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
The chain and cyclic aliphatic hydrocarbon groups may have a carbon-carbon unsaturated bond, but the chain and cyclic aliphatic saturated hydrocarbon groups are preferable. The aliphatic saturated hydrocarbon group is formed by combining a linear or branched alkyl group and a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and an alkyl group and an alicyclic saturated hydrocarbon group. An aliphatic hydrocarbon group.

Examples of chain aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and n-decyl. Group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-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.
^Examples of the substituent for R ^a42 include a halogen atom or a group represented by the formula (a-g3). As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, Preferably it is a fluorine atom.
[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents a C ^1-17 aliphatic hydrocarbon group having at least one halogen atom.
* Represents a bond. ]

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

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (a-g3). .
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 a C ^1-17 divalent aliphatic hydrocarbon group which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47, and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond with 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.

The aliphatic hydrocarbon groups of A ^a42 , A ^a43 and A ^{a44 in} the group represented by the formula (a-g1) may have a carbon-carbon unsaturated bond, Group saturated hydrocarbon groups and groups formed by combining these are preferred. The aliphatic saturated hydrocarbon group is formed by combining a linear or branched alkyl group and a monocyclic or polycyclic alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group. An aliphatic hydrocarbon group etc. are mentioned. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, Examples include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent for the aliphatic hydrocarbon group of A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

Examples of the group represented by the formula (a-g1) in which X ^a42 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 .

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

Examples of the structural unit (a4) include a structural unit represented by the formula (a4-4).
[In 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. ]

The hydrocarbon group having a fluorine atom of R ^f22 includes a chain and a cyclic aliphatic hydrocarbon group and an aromatic hydrocarbon group, and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group (straight or branched) 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 ^f22 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, 1- (trifluoromethyl) -2,2,2-trifluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3 , 3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl 2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2 , 2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, 2- (perfluoro Butyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5 Fluorinated alkyl groups such as 6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl group can be mentioned.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.
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 the structural unit represented by the 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 structural unit represented by formula (a4-4) include structural units in which the methyl group corresponding to R ^f21 is replaced with a hydrogen atom in the following structural units and structural units represented by the following formulas. It is done.

  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)>
Examples of the non-elimination hydrocarbon group that the structural unit (a5) has include a group having a linear, branched, or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably includes a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1).
[In the formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. . However, the hydrogen atom bonded to the carbon atom at the coupling position with the L ⁵⁵ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a methylene group contained in the saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. ]

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

Examples of the divalent saturated hydrocarbon group for L ⁵⁵ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. .
Examples of the divalent aliphatic saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group.
The divalent alicyclic saturated hydrocarbon group 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 group in which the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group include groups represented by formulas (L1-1) to (L1-4). In the following formula, * represents a bond with an oxygen atom.
In formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.

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

As group represented by a formula (L1-1), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-2), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-3), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-4), the bivalent group shown below is mentioned, for example.

L ⁵¹ is preferably a single bond or a group represented by the formula (L1-1).

As the structural unit (a5-1), structural units shown below and structural units in which a methyl group corresponding to R ⁵¹ in the following structural units is replaced with a hydrogen atom can be mentioned.
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%.

<Structural unit (II)>
The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as “structural unit (II)”). Includes a structural unit described in JP-A-2006-79235, and a structural unit having a sulfonate group or a carboxylate group in the side chain (an organic cation as a counter ion for these groups is also included in the side chain) or side It is preferably a structural unit having a sulfonio group (—S ⁺ (R) (R ′)) in the chain (an organic anion as a counter ion for this group is also included in the side chain).

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

Examples of the halogen atom represented by R ^III3 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^III3 , an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 and The same can be mentioned.
Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. Can be mentioned.

Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by ^XIII3 include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. These may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , 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.

Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group is replaced by —O—, —S—, or —CO— include divalent groups represented by formula (X1) to formula (X53), for example. Can be mentioned. However, the number of carbon atoms before —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O—, —S—, or —CO— is 17 or less. In the following formulas, * represents a bond to ^{A x1.}

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

Examples of organic cations represented by Za ⁺ include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, organic benzothiazolium cations, and organic phosphonium cations. Organic sulfonium cations and organic iodonium cations Are preferred, and arylsulfonium cations are more preferred.
Specifically, the thing similar to what was illustrated with the organic cation in salt (aa) is mentioned.

The structural unit represented by the formula (II-2-A ′) is preferably a structural unit represented by the formula (II-2-A).
[In formula (II-2-A), R ^III3 , X ^III3 and Za ⁺ represent the same meaning as described above.
Z represents an integer of 0 to 6.
R ^III2 and R ^III4 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 ^III2 and R ^III4 are the same as each other It may be different or different.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

^{Examples of} the C 1-6 perfluoroalkyl group represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same as the C 1-6 perfluoroalkyl group represented by Q ¹ .

The structural unit represented by the formula (II-2-A) is preferably a structural unit represented by the formula (II-2-A-1).
[In the formula (II-2-A-1)
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and Za ⁺ represent the same meaning as described above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ² represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O—, —S— or —CO—. The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by R ^III5 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include linear or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group.
Examples of the divalent saturated hydrocarbon group having 1 to 11 carbon atoms represented by X ² include those having up to 11 carbon atoms in the divalent saturated hydrocarbon group represented by X ^III3 .

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 Formula (II-2-A-2), R ^III3 , R ^III5 and Za ⁺ 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 WO2012 / 050015. Za ⁺ represents an organic cation.

The structural unit having a sulfonio group and an organic anion in the side chain is a structural unit represented by the formula (II-1-1) (hereinafter sometimes referred to as the structural unit (II-1-1)). Is preferred.
[In the formula (II-1-1),
A ^II1 represents a single bond or a divalent linking group.
R ^II represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
R ^II4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A ⁻ represents an organic anion. ]
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
Examples of the hydrocarbon group having 1 to 18 carbon atoms represented by R ^II2 and ^{R II3,} include those similar to the hydrocarbon group having 1 to 18 carbon atoms represented by ^{R 1.}
Examples of the halogen atom represented by R ^II4 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^II4 , an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 ; The same can be mentioned.
Examples of the divalent linking group represented by A ^II1 include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is: -O-, -S- or -CO- may be substituted. Specifically, the same thing as a C1-C18 bivalent saturated hydrocarbon group represented by ^XIII3 is mentioned.

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

A ^- The organic anion represented by a sulfonic acid anion, sulfonyl imide anion, methide anion and a carboxylate anion, and the like. A ^- organic anion represented by the sulfonate anion are preferable, and more preferably an anion contained in the above-mentioned acid generator (B1).

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

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

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

The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s).
The structural unit (a1) is preferably at least one selected from 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) or 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) 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 formula (a3-1-1) to formula (a3-1-4), formula (a3-2-1) to formula (a3-2-4). And at least one selected from structural units represented by formula (a3-4-1) to formula (a3-4-2).

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 content rate of each structural unit which resin (A) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less). In the present specification, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

<Resin (X) other than Resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin containing the structural unit (a4) (hereinafter sometimes referred to as “resin (X)”).
Examples of the structural unit that the resin (X) may further include the structural unit (a1), the structural unit (a2), the structural unit (a3), the structural unit (a5), and other known structural units.
The resin (X) is more preferably a resin composed of the structural unit (a4) and / or the structural unit (a5).
When the resin (X) contains the structural unit (a4), the content is preferably 40 mol% or more, more preferably 45 mol% or more, and more preferably 50 mol% or more with respect to all the structural units of the resin (X). Is more preferable.
When the resin (X) contains the structural unit (a5), the content is preferably 10 to 60 mol%, more preferably 20 to 55 mol%, based on all the structural units of the resin (X). 50 mol% is more preferable.

Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do. The content rate of each structural unit which resin (X) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 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 contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass with respect to 100 parts by mass of the resin (A). Preferably it is 1-40 mass parts, Most preferably, it is 2-30 mass parts.

  80 mass% or more and 99 mass% or less are preferable with respect to solid content of a resist composition, and, as for the total content rate of resin other than resin (A) and resin (A), 90 mass% or more and 99 mass% or less are preferable. . The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) is usually 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. It is. 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.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate Esters such as acetone, methyl isobutyl ketone, ketones such as 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One kind of the solvent (E) may be contained alone, or two or more kinds may be contained.

<Quencher (C)>
The resist composition of the present invention may contain a quencher (hereinafter sometimes referred to as “quencher (C)”). The quencher (C) may be a basic nitrogen-containing organic compound or a salt that generates an acid having a lower acidity than the acid generator (B).

<Basic nitrogen-containing organic compound>
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.

  Specifically, 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, Triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyl Cyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldinonylamine Decylamine, 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-methyl Imidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine, and the like are preferable, diisopropylaniline is preferable, and 2,6-diisopropylaniline is particularly preferable.

  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.

<Salt that generates acid with low acidity>
The acidity in a salt that generates an acid having a weaker acidity than the acid generated from the acid generator is indicated by an acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the acid generator is a salt in which the pKa of the acid generated from the salt is usually -3 <pKa, preferably -1 <pKa <7. More preferably, the salt is 0 <pKa <5. Examples of the salt that generates an acid weaker than the acid generated from the acid generator include a salt represented by the following formula, a weak acid inner salt described in JP-A-2015-147926, and JP-A-2012-229206. Examples thereof include salts described in JP 2012-6908 A, JP 2012-72109 A, JP 2011-39502 A, and JP 2011-191745 A.

Moreover, as a quencher, the weak acid intramolecular salt (D) as shown below is mentioned.

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

<Other ingredients>
The resist composition of the present invention may contain components other than the above components (hereinafter sometimes referred to as “other components (F)”) as 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 is a mixture of resin (A) and salt (aa), and resin (X), quencher (C), solvent (E) and other components (F) used as necessary. Can be prepared. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature from 10-40 degreeC according to the kind etc. of resin etc., the solubility with respect to solvents (E), such as 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) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  The resist composition can be applied onto the substrate by a commonly used apparatus such as a spin coater. Examples of the substrate include 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, irradiating 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., and the development time is preferably 5 to 300 seconds. 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)

  Moreover, the structure of the compound was confirmed by measuring molecular ion peaks using mass spectrometry (LC: Model 1100 manufactured by Agilent, MASS: LC / MSD manufactured by Agilent). In the following examples, the value of this molecular ion peak is indicated by “MASS”.

Example 1: Synthesis of a salt represented by the formula (I-1)
10 parts of the salt represented by the formula (I-1-a) and 80 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.1 parts of the compound represented by the formula (I-1-b) is added, and the mixture is further stirred at 60 ° C. for 2 hours, and represented by the formula (I-1-c). A solution containing salt was obtained.
To the obtained solution containing the salt represented by the formula (I-1-c), 4.4 parts of the compound represented by the formula (I-1-d) was added and stirred at 23 ° C. for 12 hours. To the obtained mixture, 10 parts of acetonitrile and 30 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, and separated to take out an organic layer. 30 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 40 parts of tert-butyl methyl ether was added to the concentrated mass, stirred, and then filtered to obtain 9.02 parts of the salt represented by the formula (I-1). .
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 369.0

Example 2: Synthesis of a salt represented by the formula (I-2)
10 parts of the salt represented by the formula (I-2-a) and 80 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.1 parts of the compound represented by the formula (I-2-b) was added, and the mixture was further stirred at 60 ° C. for 2 hours, thereby being represented by the formula (I-2-c). A solution containing the salt to be obtained was obtained.
To the obtained solution containing the salt represented by the formula (I-2-c), 4.6 parts of the compound represented by the formula (I-2-d) was added and stirred at 23 ° C. for 12 hours. To the obtained mixture, 30 parts of ion-exchanged water was added, stirred at 23 ° C. for 30 minutes, and separated to take out the organic layer. This operation was repeated 6 times. The obtained organic layer was concentrated to obtain 11.92 parts of the salt represented by the formula (I-2).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 381.1

Example 3: Synthesis of a salt represented by the formula (I-3)
10 parts of the salt represented by the formula (I-3-a) and 80 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.1 parts of the compound represented by the formula (I-3-b) is added, and the mixture is further stirred at 60 ° C. for 2 hours, and represented by the formula (I-3-c). A solution containing salt was obtained.
To the obtained solution containing the salt represented by the formula (I-3-c), 3.4 parts of the compound represented by the formula (I-3-d) was added and stirred at 23 ° C. for 12 hours. To the obtained mixture, 10 parts of acetonitrile and 30 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, and separated to take out an organic layer. 30 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 40 parts of tert-butyl methyl ether was added to the concentrated mass, stirred, and then filtered to obtain 4.88 parts of the salt represented by the formula (I-3). .
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ⁻ 321.0

Example 4: Synthesis of salt represented by formula (I-4)
10 parts of the salt represented by the formula (I-4-a) and 80 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.1 parts of the compound represented by the formula (I-4-b) is added, and the mixture is further stirred at 60 ° C. for 2 hours, and represented by the formula (I-4-c). A solution containing salt was obtained.
To the obtained solution containing the salt represented by the formula (I-4-c), 4.2 parts of the compound represented by the formula (I-4-d) was added and stirred at 23 ° C. for 12 hours. To the obtained mixture, 10 parts of acetonitrile and 30 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, and separated to take out an organic layer. 30 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 40 parts of tert-butyl methyl ether was added to the concentrated mass, stirred, and then filtered to obtain 4.12 parts of the salt represented by the formula (I-4). .
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 361.1

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.

Synthesis Example 1 [Synthesis of Resin A1]
As the monomer, using monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-1) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-1): monomer (a3-1-1)] It mixed so that it might become 28: 15: 5: 10: 42, and 1.5 mass times of methyl ethyl ketone of the total monomer amount was added, and it was set as the solution. As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of monomers, and heated at 75 ° C. 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 resulting resin is added to a methanol / water mixed solvent, repulped, and then filtered twice, and a copolymer having a weight average molecular weight of 5.5 × 10 ^{3 is obtained} at a yield of 70%. Obtained. This copolymer has the following structural units, and is designated as resin A1.

Synthesis Example 2 [Synthesis of Resin A2]
As the monomer, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-1), monomer (a3-1-1) and monomer ( II-2-A-1-1) and its molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2- 1): Monomer (a3-1-1): Monomer (II-2-A-1-1)] is the same as Synthesis Example 1 except that the mixture is 28: 15: 5: 7: 42: 3 The copolymer having a weight average molecular weight of 5.6 × 10 ³ was obtained in a yield of 45%. This copolymer has the following structural units and is designated as resin A2.

<Preparation of resist composition>
The mixture obtained by mixing and dissolving each component and solvent shown in Table 2 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
<Acid generator (B)>
B1-25: salt represented by formula (B1-25); synthesized by the method described in JP2011-126869A
<Salt (I)>
I-1: salt represented by formula (I-1) I-2: salt represented by formula (I-2) IX-1: synthesized by the method described in JP2010-039476IX-2: Synthesis by the method described in JP2012-126708A
<Quencher>
C1: synthesized by the method described in JP2011-39502A
<Solvent>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 150 parts γ-butyrolactone 5 parts <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 2. 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 the exposure, post exposure baking is performed for 60 seconds on the hot plate at the temperature indicated in the “PEB” column of Table 2 and paddle development is further 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.

  Line edge roughness evaluation (LER): The width of unevenness on the side wall surface of a resist pattern manufactured with effective sensitivity was measured with a scanning electron microscope to determine line edge roughness. The results are shown in Table 3.

(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 2. The composition layer formed on the wafer was exposed to a line and space pattern using an EUV exposure machine while changing the exposure amount stepwise.
After the exposure, post exposure baking is performed for 60 seconds on the hot plate at the temperature indicated in the “PEB” column of Table 2 and paddle development is further 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 30 nm were 1: 1 was defined as effective sensitivity.

  Line edge roughness evaluation (LER): The width of unevenness on the side wall surface of a resist pattern manufactured with effective sensitivity was measured with a scanning electron microscope to determine line edge roughness. The results are shown in Table 4.

  Since the salt, acid generator and resist composition of the present invention are excellent in line edge roughness (LER) of the resulting resist pattern, they are suitable for fine processing of semiconductors and are extremely useful industrially.

Claims (10)

A salt having a group represented by the formula (aa1) or a group represented by the formula (aa2).
[Where:
R ¹ and R ² each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 18 carbon atoms that may have a hydroxy group, and —CH ₂ — contained in the hydrocarbon group. May be replaced by -O- or -CO-.
X ¹ represents a hydroxy group and a hydrocarbon group having 1 to 18 carbon atoms which may have a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is replaced with —O— or —CO—. It may be.
R ³³ represents a C 1-18 divalent hydrocarbon group which may have a single bond or a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. May be replaced.
R ¹¹ , R ²² and R ³ each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 18 carbon atoms which may have a hydroxy group, and R ¹¹ and R ²² are A divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms may be formed together with the carbon atom to which they are bonded, and —CH ₂ — contained in the hydrocarbon group is —O— or — It may be replaced by CO-.
X ¹¹ represents a C 1-18 divalent hydrocarbon group which may have a single bond or a hydroxy group, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. May be replaced.
* Represents a bond. ]   A salt having a group represented by the formula (aa1) or a group represented by the formula (aa2) is obtained from an anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) and a cation. The salt according to claim 1.   An anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) is an anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) and a sulfonate. The salt according to claim 2. The salt according to claim 3, wherein the anion having a group represented by the formula (aa1) or a group represented by the formula (aa2) and a sulfonate is an anion represented by the formula (AA1) or the formula (AA2).
[Wherein R ¹ , R ² , R ³ , R ¹¹ , R ²² , R ³³ , X ¹ and X ¹¹ represent the same meaning as described above.
Q ¹ , Q ² , Q ¹¹ and Q ¹² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Q ³ , Q ⁴ , Q ¹³ and Q ¹⁴ each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group.
m1 and m2 each independently represents an integer of 0 to 6. When m1 is 2 or more, the plurality of Q ³ and Q ⁴ may be the same as or different from each other. When m2 is 2 or more, the plurality of Q ¹³ and Q ¹⁴ may be the same as or different from each other.
X ¹¹¹ represents * 1-CO—O—, * 1-O—CO—, * 1-O—CO—O—, * 1-CO—O—A ¹ —O—, * 1-CO—O—. A ¹ -CO-, * 1-CO-O-A ¹ -CO-O-, * 1-O-CO-O-A ¹ -O-, * 1-O-CO-O-A ¹ -CO- Or * 1-O—CO—O—A ¹ —CO—O—, wherein * 1 is a bond to —C (Q ¹ ) (Q ² ) — or —C (Q ³ ) (Q ⁴ ) —. Represents the place.
X ¹²¹ represents * 2-CO—O—, * 2-O—CO— or * 2-O—CO—O—, and * 2 represents —C (Q ¹¹ ) (Q ¹² ) — or —C This represents the bonding position with (Q ¹³ ) (Q ¹⁴ )-.
A ¹ represents a divalent hydrocarbon group having 1 to 18 carbon atoms. ] R ^<33> is a single bond, The salt in any one of Claims 1-4. X < ¹¹ > is a single bond, The salt in any one of Claims 1-4.   The acid generator containing the salt in any one of Claims 1-6.   A resist composition comprising the acid generator according to claim 7 and a resin having an acid labile group.   Furthermore, the resist composition of Claim 8 containing the salt which generate | occur | produces the acid whose weakness is weaker than the acid generated from an acid generator. (1) The process of apply | coating the resist composition of Claim 8 or 9 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,
A method for producing a resist pattern including: