JP6783626B2 - Method for Producing Salt, Acid Generator, Resist Composition and Resist Pattern - Google Patents

Description

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

Patent Document 1 describes a salt represented by the following formula.
Patent Document 2 describes a resist composition containing a salt represented by the following formula as an acid generator.

Japanese Unexamined Patent Publication No. 2011-46694 Japanese Unexamined Patent Publication No. 2012-229206

With the resist composition containing the above salts, the CD uniformity (CDU) of the obtained resist pattern may not always be satisfactory.

The present invention includes the following inventions.
[1] A salt represented by the formula (I).
[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Ad represents an adamantane triyl group.
Z ⁺ represents an organic cation. ]
[2] The salt according to [1], wherein L ^b1 is a group represented by any of the formulas (b1-1) to (b1-3), and * represents a binding site with CQ ¹ Q ² .
[In equation (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 hydrocarbon group may be substituted. 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 equation (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 hydrocarbon group may be substituted. 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 equation (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 hydrocarbon group may be substituted. 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. ]
[3] An acid generator containing the salt according to [1] or [2] as an active ingredient.
[4] A resist composition containing a salt represented by the formula (I0) and a resin having an acid unstable group.
[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Ad ₁ represents an adamantandiyl group or an adamantane triyl group.
n represents 1 or 2.
Z ⁺ represents an organic cation. ]
[5] The resist composition according to [4], which contains a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[6] (1) A step of applying the resist composition according to [4] or [5] onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
A method for producing a resist pattern, which comprises a step of (4) heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

Provided are salts capable of producing a resist pattern with good CD uniformity (CDU).

As used herein, the term "(meth) acrylate" means "at least one of acrylate and methacrylate," respectively. Notations such as "(meth) acrylic acid" and "(meth) acryloyl" have the same meaning.
Further, unless otherwise specified, a group capable of taking a linear, branched and / or ring such as an "aliphatic hydrocarbon group" includes any of them. The "aromatic hydrocarbon group" also includes a group in which a hydrocarbon group is bonded to an aromatic ring. If stereoisomers are present, they include all stereoisomers.
In the present specification, the "solid content of the resist composition" means the total amount of the components excluding the solvent (E) described later from the total amount of the resist composition.

[Salt (I)]
The salt of the present invention is a salt having the following formula (I) (hereinafter, may be referred to as “salt (I)”).
[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Ad represents an adamantane triyl group.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group of Q ¹ and Q ^2, a trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group, perfluoro-tert- butyl group, perfluoropentyl group, perfluoro Hexyl groups and the like can be mentioned.
Q ¹ and Q ² are independently, preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group represented by L ^b1 include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and two or more of these groups. May be a combination of.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-Diyl Group, Octane-1,8-Diyl Group, Nonan-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. Alcandiyl group;
Ethan-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, etc. Valuable alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. The group etc. can be mentioned.

The group in which the methylene group contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with an oxygen atom or a carbonyl group is represented by any of the formulas (b1-1) to (b1-3). Group is mentioned. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with CQ ¹ Q ² .
In equation (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 hydrocarbon group may be substituted. 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 equation (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 hydrocarbon group may be substituted. 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 equation (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 hydrocarbon group may be substituted. 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 the formulas (b1-1) to (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbon atoms before the replacement is the saturated hydrocarbon group. The number of carbon atoms in.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .

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

Of these, the groups represented by the formula (b1-1) or the formula (b1-3) are preferable.
Examples of the formula (b1-1) include groups represented by the formulas (b1-4) to (b1-8).
In equation (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In equation (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
However, the total number of carbon atoms of L ^b9 and L ^b10 is 20 or less.
In equation (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
However, the total number of carbon atoms of L ^b11 and L ^b12 is 21 or less.
In equation (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
However, the total number of carbon atoms of L ^b13 , L ^b14 and L ^b15 is 19 or less.
In equation (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
However, the total number of carbon atoms of L ^b16 , L ^b17 and L ^b18 is 19 or less.

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

Examples of the formula (b1-3) include groups represented by the formulas (b1-9) to (b1-11).
In equation (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. .. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total number of carbon atoms of L ^b19 and L ^b20 is 23 or less.
In equation (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. .. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In equation (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. .. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, L ^b24, the total number of carbon atoms of L ^b25 and L ^b26 is 21 or less.

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

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

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

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

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

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

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

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

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

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

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

The three bonds of the adamantane triyl group of Ad can be at any position.

Examples of the anion of the salt (I) include anions represented by the following.

Examples of the cation Z ⁺ in the salt (I) include organic onium cations, for example, organic sulfonium cations, organic iodinenium cations, organic ammonium cations, benzothiazolium cations, organic phosphonium cations, and the like, preferably organic sulfonium cations or organics. It is an iodonium cation, more preferably an aryl sulfonium cation.
Of these, cations represented by any 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) are preferable.
In equations (b2-1) to (b2-4),
R ^{b4 to} R ^b6 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 may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may be combined to form a ring containing a sulfur atom to which they are bonded, and the methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group. ..
R ^b7 and R ^b8 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 ^b7s may be the same or different, and when n2 is 2 or more, the plurality of R ^b8s may be the same or different.
R ^b9 and R ^b10 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 be combined to form a ring containing a sulfur atom to which they are bonded, and the methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group. ..
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and is contained in the aliphatic hydrocarbon group. The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be an alkoxy group having 1 to 12 carbon atoms or 1 to 12 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b1 and R ^b12 may be combined to form a ring containing -CH-CO- to which they are bonded, and the methylene group contained in the ring may be an oxygen atom, a sulfinyl group or a carbonyl group. It may be replaced.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0-4.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13s are the same or different, when p2 is 2 or more, a plurality of R ^b14s are the same or different, and when q2 is 2 or more, a plurality of R ^b15s are the same or different. when r2 is 2 or more, plural R ^b16 same or different, when s2 is 2 or more, plural R ^b17 same or different, when t2 is 2 or more, plural R ^b18 same or different different.

The aliphatic hydrocarbon group includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group and n-octyl. Examples include alkyl groups of groups and 2-ethylhexyl groups. In particular, the aliphatic hydrocarbon groups of R ^{b9 to} R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a cyclo. Cycloalkyl groups such as a heptyl group, a cyclooctyl group and a cyclodecyl group can be mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.
In particular, the alicyclic hydrocarbon groups of R ^{b9 to} R ^b12 preferably have 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.

Examples of the alicyclic hydrocarbon group in which the 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. Can be mentioned. In the alicyclic hydrocarbon group in which the 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.

The aromatic hydrocarbon group includes a phenyl group, a tolyl group, a xsilyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a p-cyclohexylphenyl group and a p-adamantylphenyl group. , Biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and other aryl groups.
When the aromatic hydrocarbon group contains an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alicyclic hydrocarbon having 3 to 18 carbon atoms is used. Groups are preferred.
Examples of the aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the aliphatic hydrocarbon group in which the hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group 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 a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group.

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

The ring formed by R ^b9 and R ^b10 together may be a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring, or an unsaturated ring. The ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, a 1,4-oxatian-4-ium ring and the like can be mentioned.
The ring formed by R ^b11 and R ^b12 together may be a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring, or an unsaturated ring. The ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

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

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

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

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

The salt (I) is a combination of the above-mentioned sulfonic acid anion and organic cation. These anions and cations can be combined arbitrarily. Specific examples of the salt (I) are shown in Table 1.
In Table 1, the salt (I-1) is the salt shown below.

Among them, the salt (I) is salt (I-1), salt (I-2), salt (I-3), salt (I-6), salt (I-7), salt (I-8). , Salt (I-9), Salt (I-12), Salt (I-13), Salt (I-14), Salt (I-15), Salt (I-18), Salt (I-19), Salt (I-20), salt (I-21), salt (I-24) salt (I-25), salt (I-26), salt (I-27), salt (I-30), salt ( I-31), salt (I-32), salt (I-33), salt (I-36), salt (I-37), salt (I-38), salt (I-39) and salt (I) −42) is preferable.

The salt represented by the formula (I1) (the salt (I) when L ^b1 is a group represented by * -CO-O- (* represents the binding site with CQ ¹ Q ² )) is For example, it can be obtained by reacting a salt represented by the formula (I1-a) with water in a solvent in the presence of an acid.
(In the formula, all the symbols have the same meanings as described above.)
Examples of the acid include hydrochloric acid and the like.
Examples of the solvent include acetonitrile, dimethylformamide, methyl isobutyl ketone, chloroform, tetrahydrofuran, toluene and the like.

For the salt represented by the formula (I1-a), for example, the salt represented by the formula (I1-b) and the compound represented by the formula (I1-c) are reacted in a solvent such as acetonitrile. It can be manufactured by.
(In the formula, all the symbols have the same meanings as described above.)

The compound represented by the formula (I1-b) is obtained by reacting the compound represented by the formula (I1-d) with the compound represented by the formula (I1-e) in a solvent such as acetonitrile. Obtainable.
(In the formula, all the symbols have the same meanings as described above.)
Examples of the compound represented by the formula (I1-d) include compounds represented by the following, which can be produced by the method described in JP-A-2008-127365.

In the compound represented by the formula (I1-c), the compound represented by the formula (I1-f) and the compound represented by the formula (I1-g) are reacted in a solvent in the presence of a base catalyst. Can be obtained by
(In the formula, all the symbols have the same meanings as described above.)
Examples of the base catalyst include triethylamine and sodium hydroxide.
Examples of the solvent include acetone and methanol.

Examples of the compound represented by the formula (I1-f) include compounds represented by the following, which are easily available on the market.

When the salt represented by the formula (I2) (L ^b1 is a group represented by * -CO-O-CH _2- CO-O- (* represents the binding site with CQ ¹ Q ² )) The salt (I)) can be obtained, for example, by reacting a salt represented by the formula (I2-a) with water in a solvent in the presence of an acid.
The salt represented by the formula (I2-a) is prepared by, for example, mixing a salt represented by the formula (I2-b) and a compound represented by the formula (I2-c) in a solvent in the presence of a base catalyst. It can be produced by reacting. Examples of the base catalyst include potassium carbonate, potassium iodide, triethylamine, sodium hydroxide and the like. Examples of the solvent include tetrahydrofuran, chloroform and the like.
Examples of the compound represented by the formula (I2-b) include compounds represented by the following, which can be produced by the method described in JP-A-2008-127365.

In the compound represented by the formula (I2-c), the compound represented by the formula (I1-c) and the compound represented by the formula (I2-d) are reacted in a solvent in the presence of a base catalyst. Can be obtained by Examples of the base catalyst include potassium carbonate, potassium iodide, triethylamine, sodium hydroxide and the like. Examples of the solvent include tetrahydrofuran, chloroform and the like.

[Acid generator]
The acid generator of the present invention is an acid generator containing salt (I) as an active ingredient. In the acid generator of the present invention, salt (I0) may be used as the active ingredient instead of salt (I). The acid generator of the present invention may contain the salt (I) alone, or may contain two or more kinds of the salt (I).
The acid generator of the present invention may contain an acid generator known in the resist field other than the salt (I) and the salt (I0) (hereinafter, may be referred to as “acid generator (B)”).
[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Ad ₁ represents an adamantandiyl group or an adamantane triyl group.
n represents 1 or 2.
Z ⁺ represents an organic cation. ]
The bond of the adamantandiyl group and the adamantantriyl group of Ad can be at any position.

Examples of the salt (I0) other than the salt (I) include salts represented by the following.

In the above salt, a salt (I0) in which the cation (b2-c-1) is replaced with a cation represented by any of the formulas (b2-1) to (b2-4) is also mentioned.

When the salt (I) and / or the salt (I0) and the acid generator (B) are contained as the acid generator, the salt (I) and / or the salt (I0) and the acid generator (B) are contained. The amount ratio (mass ratio; salt (I) and / or salt (I0): acid generator (B)) is usually 1:99 to 99: 1, preferably 2:98 to 98: 2, more preferably. Is 5:95 to 95: 5, more preferably 10:90 to 90:10.

[Resist composition]
The resist composition of the present invention contains the above-mentioned acid generator containing a resin having an acid unstable group (hereinafter sometimes referred to as "resin (A)") and a salt (I) and / or a salt (I0). contains. Here, the "acid-unstable group" is a structural unit having a leaving group, the leaving group being removed by contact with an acid, and the constituent unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). Means the group that converts to.
The resist composition further preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)"). ..

<Acid generator>
The resist composition of the present invention preferably contains a salt (I0) as an acid generator. When the salt (I0) is used as an acid generator, the content of the salt (I0) is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, based on the resin (A). preferable.

<Acid generator (B)>
As the acid generator (B), a known acid generator can be used, and it may be an ionic acid generator or a nonionic acid generator. Preferably, it is an ionic acid generator. Examples of the ionic acid generator include an ionic acid generator composed of a combination of an anion constituting salt (I) and a cation other than cation Z ⁺ , and an ionic acid generator composed of a combination of a known cation and a known anion. Agents are mentioned.

Examples of the acid generator (B) include organic sulfonic acids and organic sulfonium salts. For example, the acid generation described in JP2013-68914, JP2013-3155, and JP2013-1905. Agents and the like can be mentioned. Specific examples thereof include salts represented by any of the formulas (B1-1) to (B1-40). Of these, those containing an aryl sulfonium cation are preferable, and formula (B1-1), formula (B1-2), formula (B1-3), formula (B1-6), formula (B1-7), formula (B1-11). ), Equation (B1-12), Equation (B1-13), Equation (B1-14), Equation (B1-20), Equation (B1-21), Equation (B1-22), Equation (B1-23). , Equation (B1-24), Equation (B1-25), Equation (B1-26), Equation (B1-29), Equation (B1-31), Equation (B1-32), Equation (B1-33), Any of formula (B1-34), formula (B1-35), formula (B1-36), formula (B1-37), formula (B1-38), formula (B1-39) or formula (B1-40) The salt represented by is more preferable.

The acid generator (B) may contain one type alone or two or more types.
The content of the acid generator (B) is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, and 3 to 15% by mass with respect to the resin (A). Is even more preferable.
When the salt (I0) and the acid generator (B) are used as the acid generator in the resist composition, the contents of the salt (I0) and the acid generator (B) are preferably relative to the resin (A). Is 1.5% by mass or more (more preferably 3% by mass or more), preferably 40% by mass or less (more preferably 35% by mass or less).

<Resin (A)>
The resin (A) has a structural unit having an acid unstable group (hereinafter, may be referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). Structural units other than the structural unit (a1) include structural units having no acid-labile group (hereinafter sometimes referred to as “structural unit (s)”), structural units (a1), and structural units other than the structural unit (s). Structural units and other structural units derived from monomers known in the art can be mentioned.

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid unstable group (hereinafter, may be referred to as “monomer (a1)”).
The acid unstable group contained in the resin (A) is preferably a group (1) and / or a group (2).
[In the formula (1), R ^{a1 to} R ^a3 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group combining these groups, or R. ^a1 and R ^a2 bond with each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]
[In the 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. Represented, 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 and X to which they are bonded, and the hydrocarbon group and the divalent complex. -CH ₂ − contained in the ring group may be replaced with −O − or −S−.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

^Examples of the alkyl group of R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and the like.
The alicyclic hydrocarbon groups of R ^{a1 to} R ^a3 may be either 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 groups (* indicates a bond). The alicyclic hydrocarbon groups of R ^{a1 to} R ^a3 are preferably alicyclic hydrocarbon groups having 3 to 16 carbon atoms.
Examples of the group in which the alkyl group and the alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, a norbornylethyl group and the like. Can be mentioned.
na is preferably 0.

Examples of -C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R a ² are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

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

Examples of the hydrocarbon group R ^{a1 '~R a3',} an alkyl group, an alicyclic hydrocarbon group, and a group formed by combining an aromatic hydrocarbon group and thereof.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as above.
The aromatic hydrocarbon group includes a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a trill group, a xsilyl group, a cumenyl group, a mesityl group and a biphenyl group. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.
^{Examples of the} divalent heterocyclic group formed by R ^a2'and R ^a3'bonding to each other together with the carbon atom and X to which they are bonded include the following groups. * Represents a bond.
Of R ^{a1 'and} R ^a2', it is preferable that at least one is a hydrogen atom.

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

Among the (meth) acrylic monomers having an acid unstable 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.

As the structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1), the structural unit represented by the formula (a1-0) is preferably represented by the formula (a1-1). Examples thereof include a structural unit or a structural unit represented by the formula (a1-2). These may be used alone or in combination of two or more. In the present specification, the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), and the structural unit represented by the formula (a1-2) are each structural unit (a1). −0), structural unit (a1-1) and structural unit (a1-2), monomer for inducing structural unit (a1-0), monomer for inducing structural unit (a1-1) and structural unit (a1-) The monomer that induces 2) may be referred to as a monomer (a1-0), a monomer (a1-1), and a monomer (a1-2), respectively.

In the resin (A), the content of the structural unit (a1) is preferably 10 to 99 mol%, more preferably 20 to 97 mol%, and further, with respect to all the structural units of the resin (A). It is preferably 30 to 95 mol%.

[In equation (a1-0),
L ^a01 represents an oxygen atom or _{^{* -O- (CH 2) k01 -CO}} -O- the stands, k01 represents an integer of 1-7, * represents a bond to a carbonyl group.
R ^a01 represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these groups. ]

[In the formula (a1-1) and the formula (a1-2),
L ^a1 and L ^a2 independently represent −O− or ^* −O− (CH ₂ ) _k1 −CO−O−, k1 represents an integer of 1 to 7, and * is a combination with −CO− Represent a hand.
R ^a4 and R ^a5 independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 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 them.
m1 represents an integer from 0 to 14.
n1 represents an integer from 0 to 10.
n1'represents an integer from 0 to 3. ]

^La01 is preferably an oxygen atom or ^* -O- (CH ₂ ) _k01- CO-O- (where k01 is preferably an integer of 1 to 4, more preferably 1), and more. It is preferably an oxygen atom.
Examples of the alkyl group of R ^a02 , R ^a03 and R ^a04 , the alicyclic hydrocarbon group and the group combining these groups include the same groups as those mentioned in R ^{a1 to} R ^a3 of the formula (1).
The alkyl groups of R ^a02 , R ^a03 and R ^a04 preferably have 6 or less carbon atoms.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 preferably have 8 or less carbon atoms, and more preferably 6 or less carbon atoms.
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 with these alkyl groups and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a methyladamantyl group, a cyclohexylmethyl group, a methylcyclohexylmethyl group, an adamantylmethyl group, a norbornylmethyl group and the like. Be done.
R ^a02 and R ^a03 are preferably alkyl groups having 1 to 6 carbon atoms, and more preferably methyl groups or ethyl groups.
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.

^La1 and ^La2 are preferably −O− or ^* −O− (CH ₂ ) _{k1 ′} −CO−O− (where k1 ′ is an integer of 1 to 4, preferably 1). ), More preferably -O-.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group combining these groups include the same groups as those listed in R ^{a1 to} R ^a3 of the formula (1).
The alkyl groups of R ^a6 and R ^a7 preferably have 6 or less carbon atoms.
The alicyclic hydrocarbon groups of R ^a6 and R ^a7 are preferably alicyclic hydrocarbon groups having 8 or less carbon atoms, and more preferably 6 or less alicyclic hydrocarbon groups.
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 of the formulas (a1-0-1) to (a1-0-12) is preferable, and the structural units (a1-0-1) to The structural unit represented by any of the formulas (a1-0-10) is more preferable.

In the above structural units, structural units in which a methyl group is replaced by a hydrogen atom corresponding to R ^a01 may be mentioned as specific examples of the structural units (a1-0).

Examples of the monomer (a1-1) include the monomers described in JP-A-2010-204646. Among them, the monomers represented by any of the formulas (a1-1-1) to (a1-1-8) are preferable, and any one of the formulas (a1-1-1) to (a1-1-4) is preferable. The monomer represented by is more preferable.

Examples of the monomer (a1-2) include 1-methylcyclopentane-1-yl (meth) acrylate, 1-ethylcyclopentane-1-yl (meth) acrylate, and 1-methylcyclohexane-1-yl (meth). Acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptane-1-yl (meth) acrylate, 1-ethylcyclooctane-1-yl (meth) acrylate, 1-isopropylcyclopentane-1 -Il (meth) acrylate, 1-isopropylcyclohexane-1-yl (meth) acrylate and the like can be mentioned. Monomers represented by any of formulas (a1-2-1) to (a1-2-12) are preferable, and formulas (a1-2-3), formulas (a1-2-4), and formulas (a1-) are preferable. The monomers represented by 2-9) and the formula (a1-2-10) are more preferable, and the monomers represented by the formulas (a1-2-3) and the formula (a1-2-9) are further preferable.

When the resin (A) contains a structural unit (a1-0) and / or a structural unit (a1-1) and / or a structural unit (a1-2), the total content of these is the total structure of the resin (A). It is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 85 mol% with respect to the unit.

Further, as the structural unit (a1) having the group (1), a structural unit represented by the formula (a1-3) can also be mentioned. The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Further, the monomer for inducing the structural unit (a1-3) may be referred to as a monomer (a1-3).
In equation (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms, which may have a hydroxy group, a carboxy group, a cyano group, a hydrogen atom, or -COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these groups, and the aliphatic hydrocarbon group and the above. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and the aliphatic hydrocarbon group and −CH ₂ − contained in the alicyclic hydrocarbon group are −O− or −O− or. It may be replaced with −CO−.
R ^a10 , R ^a11 and R ^a12 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining them, or R ^a10 and R ^a11 bond with each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.

Here, -COOR ^a13 includes, for example, a group in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

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

Specifically, the monomer (a1-3) is 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2-carboxylic acid. Acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4) -Methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-oxo) Cyclohexyl) ethyl and 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-methylethyl and the like can be mentioned.

Since the resin (A) containing the structural unit (a1-3) contains a three-dimensionally bulky structural unit, it is higher than the resist composition of the present invention containing such a resin (A). A resist pattern can be obtained at a resolution. Further, since a rigid norbornane ring is introduced into the main chain, the obtained resist pattern tends to have excellent dry etching resistance.

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

As the structural unit (a1) having a group represented by the group (2), the structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). Can be mentioned.
[In equation (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or Represents a methacryloyloxy group.
la represents an integer from 0 to 4. When la is 2 or more, a plurality of Ra ^33s may be the same 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 Then, together with CO to which they are bonded, a divalent heterocyclic group having 3 to 20 carbon atoms is formed, and the hydrocarbon group and −CH ₂ − contained in the divalent heterocyclic group are −O−. Alternatively, it may be replaced by −S−. ]

^Examples of the alkyl group of R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
Examples of the halogen atom of R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, and 1,1,2,2-tetrafluoro. Ethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluoro Butyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,5-nonafluoropentyl group, n-pentyl group, n-hexyl group, n-perfluorohexyl group, etc. Can be mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Of these, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
Examples of the hydrocarbon group R ^a34 and R ^a35, include the same groups as R ^{a1 'and} R ^a2' of formula (2).
The R ^a36, include groups formed by alkyl groups having 1 to 18 carbon atoms, alicyclic hydrocarbon group having 3 to 18 carbon atoms, or these aromatic hydrocarbon group having 6 to 18 carbon atoms combined Be done.

In the 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 and an ethoxy group, and even more preferably a methoxy group.
The la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. It is a group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. Alkyl group and the alicyclic hydrocarbon group in R ^a36 is unsubstituted is preferred. When the aromatic hydrocarbon group in ^Ra36 has a substituent, an aryloxy group having 6 to 10 carbon atoms is preferable as the substituent.

Examples of the monomer for deriving the structural unit (a1-4) include the monomers described in JP-A-2010-204646. Among them, the monomers represented by the formulas (a1-4-1) to (a1-4-8) are preferable, and the formulas (a1-4-1) to (a1-4-5) and the formula (a1-) are preferable. The monomers represented by 4-8) are more preferable.

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

The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (2) is a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”). There is).
In equation (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
Z ^a1 represents a single bond or * − (CH ₂ ) _h3 −CO−L ⁵⁴ −, h3 represents an integer of 1 to 4, and * represents a bond with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ independently represent -O- or -S-, respectively.
s1 represents an integer of 1 to 3.
s1'represents an integer from 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Alkyl groups having 1 to 6 carbon atoms which may have a halogen atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, fluoromethyl group and trifluoromethyl. The group is mentioned.
In the 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 , it is preferable that one is −O− and the other is −S−.
s1 is preferably 1.
s1'is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * -CH _2- CO-O-.

Examples of the monomer for deriving the structural unit (a1-5) include the monomers described in JP-A-2010-61117. Among them, the monomers represented by the formulas (a1-5-1) to (a1-5-2) are preferable, and the monomers represented by the formula (a1-5-1) or the formula (a1-5-2) are preferable. Is more preferable.

When the resin (A) has a structural unit (a1-5), the content thereof is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on all the structural units of the resin (A). , 5-40 mol% is more preferred.

The structural unit (a) having an acid unstable group in the resin (A) includes a structural unit (a1-0), a structural unit (a1-1), a structural unit (a1-2), and a structural unit (a1-5). At least one or more selected from the group consisting of) is preferable, and at least two or more are more preferable, and combinations of structural units (a1-1) and structural units (a1-2), structural units (a1-1) and structural units (a1-1) Combination of a1-5), combination of structural unit (a1-1) and structural unit (a1-0), combination of structural unit (a1-2) and structural unit (a1-0), structural unit (a1-5) And a combination of structural units (a1-0), structural units (a1-0), structural units (a1-1) and structural units (a1-2), structural units (a1-0), structural units (a1-). The combination of 1) and the structural unit (a1-5) is more preferable, and the combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit (a1-5) The combination is even more preferred.
The structural unit (a1) preferably includes the structural unit (a1-1).

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no acid-labile group (hereinafter, may be referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no acid unstable group 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 not having an acid unstable group is preferable. A structure having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a lactone ring and no acid-labile group. If a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

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

Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter, may be referred to as “structural unit (a2-0)”).
[In equation (a2-0),
^Ra30 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or Represents a methacryloyloxy group.
ma represents an integer from 0 to 4. When ma is an integer of 2 or more, the plurality of Ra ^31s may be the same or different from each other. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom of ^Ra30 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, and 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 Examples include a group and an n-perfluorohexyl group. R ^a30 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkoxy group of ^Ra31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Of these, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
The ma is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0.

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

The resin (A) containing the structural unit (a2-0) undergoes a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer inducing the structural unit (a2-0) is protected with a protecting group, and then deprotected. It can be manufactured by processing. However, when the deprotection treatment is performed, it is necessary to carry out the deprotection treatment so as not to significantly impair the acid unstable group of the structural unit (a1). Examples of such a protecting group include an acetyl group and the like.

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

Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter, may be referred to as “structural unit (a2-1)”).
In equation (a2-1),
^La3 represents −O− or ^* −O− (CH ₂ ) _k2 −CO−O−.
k2 represents an integer of 1-7. * 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 from 0 to 10.

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

Examples of the monomer for inducing the structural unit (a2-1) include the monomers described in JP-A-2010-204646. Monomers represented by any of the formulas (a2-1-1) to (a2-1-6) are preferable, and the monomers represented by any of the formulas (a2-1-1) to (a2-1-4) are represented. The monomer represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferable.

When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol%, preferably 1 to 40 mol%, based on all the structural units of the resin (A). Yes, more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a fused ring of a monocyclic lactone ring and another ring. It may be. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure can be mentioned.

The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). One of these may be contained alone, or two or more thereof may be contained.

[In equation (a3-1),
^La4 represents −O− or ^* −O− (CH ₂ ) _k3 −CO−O− (k3 is an integer of 1 to 7.
) Represents a group. * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer from 0 to 5. When p1 is 2 or more, a plurality of Ra ^21s are the same or different from each other.
In equation (a3-2),
^La5 represents −O− or ^* −O− (CH ₂ ) _k3 −CO−O− (k3 is an integer of 1 to 7.
) Represents a group. * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer from 0 to 3. When q1 is 2 or more, a plurality of ^Ra22s are the same or different from each other.
In formula (a3-3),
^La6 represents −O− or ^* −O− (CH ₂ ) _k3 −CO−O− (k3 is an integer of 1 to 7.
) Represents a group. * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer from 0 to 3. When r1 is 2 or more, a plurality of ^Ra23s are the same or different from each other.
In formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
R ^a25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ^a7 is -O-, ^* -O-L ^a8- O-, ^* -O-L ^a8- CO-O-, ^* -O-L ^a8- CO-O-L ^a9- CO-O- or ^* Represents −O−L ^a8 −O−CO−L ^a9 −O−.
* Represents a bond with a carbonyl group.
^{La 8} and ^{La 9} represent an alkanediyl group having 1 to 6 carbon atoms independently of each other.
w1 represents an integer from 0 to 8. When w1 is 2 or more, the plurality of Ra ^25s may be the same or different from each other. ]

Examples of the aliphatic hydrocarbon groups of 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 can be mentioned.
Examples of the halogen atom of R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group of 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. It is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.
Alkyl groups having a halogen atom of R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro. Examples thereof include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

The alkanediyl groups of ^La8 and ^La9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group and pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples thereof include 4-diyl group and 2-methylbutane-1,4-diyl group.

In the formula (a3-1) ~ formula (a3-3), L ^a4 ~L ^a6 are each independently preferably, -O- or, k3 is an integer of from 1 to 4 * -O- (CH ₂ ) A group represented by _k3- CO-O-, more preferably -O- and * -O-CH _2- CO-O-, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently, preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are independently, preferably integers 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 further preferably a hydrogen atom or a methyl group.
L ^a7 is preferably -O- or ^* -O-L ^a8- CO-O-, and more preferably -O-, -O-CH _2- CO-O- or -OC ₂ H. _4- CO-O-.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
w1 is preferably an integer of 0 to 2, more preferably 0 or 1.
In particular, the formula (a3-4) is preferably the formula (a3-4)'.
(In the formula, R ^a24 and ^{La 7} have the same meanings as above.)

Examples of the monomer for deriving the structural unit (a3) include the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Can be mentioned. The structural unit (a3) includes equations (a3-1-1) to (a3-1-4), equations (a3-2-1) to (a3-2-4), and equations (a3-3-3). 1) The structural unit represented by any of the formulas (a3-3-4) and the formulas (a3-4-1) to the formula (a3-4-12) is preferable, and the formula (a3-1-1), It is represented by any of the formulas (a3-1-2), formulas (a3-2-3) to formulas (a3-2-4) and formulas (a3-4-1) to formulas (a3-4-12). The structural unit represented by any of the formulas (a3-4-1) to (a3-4-12) is more preferable, and the structural unit represented by any of the formulas (a3-4-1) to (a3-4-1) is more preferable. The structural unit represented by any of 4-6) is even more preferable.

In the structural unit represented by the following formula (a3-4-1) ~ formula (a3-4-12), compound methyl group corresponding to R ^a24 is replaced by a hydrogen atom, the structural unit (a3-4 ) Can be given as a specific example.

When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). , More preferably 10 to 60 mol%.
The contents of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), and the structural unit (a3-4) are each relative to all the structural units of the resin (A). 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is further preferable.

<Other structural units (t)>
As the structural unit (t), a structural unit having a halogen atom in addition to the structural unit (a2) and the structural unit (a3) (hereinafter, sometimes referred to as “structural unit (a4)”) and a non-desorbed hydrocarbon group are used. Examples thereof include a structural unit (s) having a structure (hereinafter, may be referred to as a “structural unit (a5)”).

Examples of the structural unit (a4) include a structural unit represented by the formula (a4-0).
[In equation (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group of L ⁴ include an alkanediyl group having 1 to 4 carbon atoms, for example, a methylene group, an ethylene group, a propane-1,3-diyl group and a butane-1,4-diyl group. Such as linear alkanediyl group, linear alkanediyl group having an alkyl group (particularly methyl group, ethyl group, etc.) side chain, ethane-1,1-diyl group, propane-1, Examples thereof include branched alkanediyl groups such as 2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.

The perfluoroalkanediyl group of L ³ includes a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane-2,2. -Diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2 -Diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like can be mentioned.
Examples of the perfluorocycloalkanediyl group of L ³ include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantandiyl group and the like.

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

The structural unit (a4-0), a methyl group have structural units replaced by a hydrogen atom corresponding to R ⁵ in the structural unit and the following structural units shown below.

Examples of the structural unit (a4) include a structural unit represented by the formula (a4-1).
[In equation (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and −CH ₂ − contained in the hydrocarbon group may be replaced with −O− or −CO−. Good.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by the formula (a-g1).
[In the formula (ag1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a single bond or a substituent.
X ^a41 and X ^a42 independently represent -O-, -CO-, ^-CO -O- or -O-CO-, respectively.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
Of the two bonds represented by *, the * on the right is the bond with -O-CO-R ^a42 . ]

^Examples of the hydrocarbon group of R ^a42 include a chain type and a ring type aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups.
The chain-type and cyclic-type aliphatic hydrocarbon groups may have a carbon-carbon unsaturated bond, but chain-type and cyclic-type aliphatic saturated hydrocarbon groups are preferable. The aliphatic saturated hydrocarbon group is a fat 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. Examples include group hydrocarbon groups.

The chain-type aliphatic hydrocarbon group includes methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and n-decyl. Examples thereof include a group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group and an n-octadecyl group. The cyclic aliphatic hydrocarbon group includes a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; Examples thereof include polycyclic alicyclic hydrocarbon groups such as (representing a hand).
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.

^Examples of R ^a42 include a halogen atom or a group represented by the formula ( ^ag3) as a substituent. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
[In the formula (ag3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms having at least one halogen atom.
* Represents a bond. ]

^Examples of the aliphatic hydrocarbon group of A ^{a45 include} the same groups as those exemplified in R ^a42 .
R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (ag3). ..
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 further preferably having a carbon number of carbons. It is a perfluoroalkyl group of 1 to 6, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula ( ^ag3 ), the aliphatic hydrocarbon includes the number of carbon atoms contained in the group represented by the formula (ag3). The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by the formula (ag3) is used as a substituent, the number thereof is preferably one.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula ( ^ag3 ), the aliphatic hydrocarbon includes the number of carbon atoms contained in the group represented by the formula (ag3). The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by the formula (ag3) is used as a substituent, the number thereof is preferably one.

The aliphatic hydrocarbon group having a group represented by the formula (ag3) is more preferably a group represented by the formula (ag2).
[In the formula (ag2),
A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond with a carbonyl group. ]

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

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

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

The aliphatic hydrocarbon groups A ^a42 , A ^a43 and A ^{a44 in} the group (a-g1) may have a carbon-carbon unsaturated bond, but are chain and cyclic aliphatic saturated hydrocarbon groups. In addition, a group formed by combining these is preferable. 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. Aliphatic hydrocarbon groups and the like can be 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 thereof include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the aliphatic hydrocarbon group of A ^a42 , 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 ( ^{ag1) in} which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** represent the bond, respectively, and ** is the bond with -O-CO-R ^a42 .

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

The alkanediyl group of A ^f1 includes methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, and pentane-1,5-diyl group. , Hexine-1,6-diyl group and other linear alkanediyl groups; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 Examples thereof include branched alkanediyl groups such as −diyl group, 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Alkyl groups 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 -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, cyclodecyl group and the like. Cycloalkyl groups can be mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and a norbornyl group. Examples thereof include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
As the alkyl group having a fluorine atom, 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- (perfluorobutyl) ethyl group, 1 , 1,2,2,3,3,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,5,5,6,6-dodecafluoro Fluoroalkyl groups such as hexyl groups, perfluoropentylmethyl groups and perfluorohexyl groups can be mentioned.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a fluorocycloalkyl group such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

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

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

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

The aliphatic hydrocarbon group of A ^f13 includes a chain type and a ring type aliphatic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining them. This aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include an alkandiyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group; a difluoromethylene group and a perfluoroethylene group. Examples thereof include a perfluoroalkandyl group such as a group, a perfluoropropanediyl group, a perfluorobutandyl group and a perfluoropentandyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be a group containing either a monocyclic or polycyclic group. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantandiyl group, a norbornanediyl group, and a perfluoroadamantandiyl group.

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

In the formula (a4-3), A ^f11 is an ethylene group is preferred.
The aliphatic hydrocarbon group of A ^f13 is preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and more preferably an aliphatic hydrocarbon group having 2 to 3 carbon atoms.
The aliphatic hydrocarbon group of A ^f14 is preferably an aliphatic hydrocarbon group having 3 to 12 carbon atoms, and more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms. Among them, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

Examples of the structural unit represented by the formula (a4-2) include the structural unit shown below and the structural unit in which the methyl group corresponding to R ^f1 in the following structural unit is replaced with a hydrogen atom.

The structural unit represented by formula (a4-3), a methyl group have structural units replaced by a hydrogen atom corresponding to R ^f11 in the structural unit and the following structural units shown below.

The structural unit (a4) also includes a structural unit represented by the formula (a4-4).
[In equation (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 represent an integer of 1 to 6.
R ^f22 represents a hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same hydrocarbon group as R ^f2 in the formula (a4-2). R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, and an alkyl group having 1 to 10 carbon atoms having a fluorine atom is more preferable. Preferably, an alkyl group having 1 to 6 carbon atoms having a fluorine atom is more preferable.

In the formula (a4-4), as A ^f21 , − (CH ₂ ) _j1 − is preferable, an ethylene group or a methylene group is more preferable, and a methylene group is further preferable.

Examples of the structural unit represented by the formula (a4-4) include the following structural unit and the structural unit represented by the following formula in which the methyl group corresponding to R ^f21 is replaced with a hydrogen atom. Be done.

When the resin (A) has a structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and 3) with respect to all the structural units of the resin (A). 10 mol% is more preferable.

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

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

Examples of the divalent saturated hydrocarbon group of L ⁵¹ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable. ..
Examples of the divalent aliphatic saturated hydrocarbon group include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantandiyl 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 the 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 number of carbon atoms 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 number of carbon atoms 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 number of carbon atoms 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 ^{x 1} represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total number of carbon atoms of L ^x8 , L ^x9 and W ^x1 is 15 or less.

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

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

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

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

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

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

Examples of the structural unit (a5-1) include the structural unit shown below and the structural unit in which the methyl group corresponding to R ⁵¹ in the following structural unit is replaced with a hydrogen atom.

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

The resin (A) is preferably a resin composed of a structural unit (a1) and a structural unit (s), that is, a copolymer of a monomer (a1) and a 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 and a cyclopentyl group), and more preferably the structural unit (a1). At least two kinds selected from a1-1) and a structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and 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 selected from the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-4). At least one kind.

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

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, a radical polymerization method) using a monomer for inducing these structural units. can do. The content of each structural unit of the resin (A) can be adjusted by adjusting the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, still more preferable. Is 15,000 or less).

<Resin 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 composed of only the structural unit (s), a resin containing the structural unit (a4) (however, the resin does not include the structural unit (a1); hereinafter may be referred to as "resin (X)") and the like. Can be mentioned. Of these, a resin containing the structural unit (a4) is preferable.
In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more, still more preferably 50 mol% or more, based on all the structural units of the resin (X). ..
Examples of the structural unit that the resin (X) may further include include a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers.
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 of the resin (A).
When the resist composition contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 2 to 50 parts by mass, and further, with respect to 100 parts by mass of the resin (A). It is preferably 2 to 40 parts by mass, and particularly preferably 3 to 30 parts by mass.

The total content of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, and preferably 90% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. .. In the present specification, the "solid content of the resist composition" means the total amount of the components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the content of the resin relative to the solid content can be measured by a known analytical 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 usually 99.9% by mass or less, preferably 99% by mass or less in the resist composition. Is. The content of the solvent (E) can be measured by a known analytical means such as liquid chromatography or gas chromatography.

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate. Esters; ketones such as acetone, methylisobutylketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. The solvent (E) may contain one type alone or two or more types.

<Quencher (C)>
Examples of the quencher (C) include a basic nitrogen-containing organic compound or a salt that generates an acid having a weaker acidity than the acid generated from the salt (I) and the acid generator (B).
Examples of the basic nitrogen-containing organic compound include amine and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

As the quencher (C), 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, trypentylamine, tri. Hexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyl Didecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, 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, piperazine, morpholin, piperidine and hindered amine compounds having a piperidine skeleton described in JP-A-11-52575, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1, 3-Di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2 ′ -Dipyridylamine, 2,2'-dipicolylamine, bipyridine and the like can be mentioned, preferably diisopropylaniline, and particularly preferably 2,6-diisopropylaniline.

Ammonium salts include 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.

The acidity of a salt that produces an acid that is weaker than the acid generated from the salt (I) and the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid having a weaker acidity than the acid generated from the salt (I) and the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually -3 <pKa. A salt of -1 <pKa <7 is preferable, and a salt of 0 <pKa <5 is more preferable. Examples of the salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) include a salt represented by the following formula, a weak acid intramolecular salt represented by the formula (D), and JP-A-2012-. Examples thereof include the salts described in JP-A-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745. It is preferably a weak acid intramolecular salt represented by the formula (D) (hereinafter, may be referred to as “weak acid intramolecular salt (D)”).

[In formula (D),
R ^D1 and R ^D2 independently have a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, and an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group, a nitro group or a halogen atom having 2 to 7 carbon atoms.
m'and n'independently represent integers from 0 to 4, and when m'is 2 or more, a plurality of ^RD1s are the same or different, and when n'is 2 or more, a plurality of ^RD2s are. Same or different. ]

In the weak acid intramolecular salt (D), the hydrocarbon groups of ^RD1 and ^RD2 include monovalent aliphatic hydrocarbon groups, monovalent alicyclic hydrocarbon groups, and monovalent aromatic hydrocarbon groups. Examples thereof include groups formed by combining these.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group and nonyl group.
The monovalent alicyclic hydrocarbon group may be either a monocyclic or polycyclic group, and may be saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group and cyclododecyl group, norbonyl group and adamantyl group.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group and 4-. Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, trill group, xsilyl group , Cumenyl group, mesityl group, biphenyl group, phenanthryl group, aryl group such as 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl and the like.
Examples of the group formed by combining these groups include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, and an aralkyl group (for example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1). -Propyl group, 1-Phenyl-2-propyl group, 2-Phenyl-2-propyl group, 3-Phenyl-1-propyl group, 4-Phenyl-1-butyl group, 5-Phenyl-1-pentyl group, 6 -Phenyl-1-hexyl group, etc.) and the like.

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

In the formula (D), ^RD1 and ^RD2 independently have an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms. An acyl group of 4 and an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group or a halogen atom are preferable.
For m'and n', an integer of 0 to 2 is preferable, and 0 is more preferable. When m'is 2 or more, a plurality of R ^D1s are the same or different, and when n'is 2 or more, a plurality of R ^D2s are the same or different.

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

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, based on the solid content of the resist composition. It is mass%.

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

<Preparation of resist composition>
The resist composition contains an acid generator containing a resin (A) and a salt (I) and / or a salt (I0), and if necessary, a resin other than the resin (A), an acid generator (B), and a solvent. It can be prepared by mixing (E), the quencher (C) and the other component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be selected from 10 to 40 ° C., depending on the type of resin or the like and the solubility of the resin or the like in the solvent (E). As the mixing time, an appropriate time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing or the like 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.

<Manufacturing method of resist pattern>
The method for producing a resist pattern of the present invention is
(1) A step of applying the resist composition of the present invention on a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
It includes (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 device 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 prebaking), or by 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 at the time of vacuum drying is preferably about 1~1.0 × 10 ⁵ Pa.

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

The exposed composition layer is heat treated (so-called post-exposure bake) to promote the deprotection reaction at the acid unstable group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

The composition layer after heating is usually developed using a developing solution using a developing device. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The developing temperature is preferably 5 to 60 ° C., and the developing 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 a positive resist pattern is produced from a resist composition, an alkaline developer is used as the developer. The alkaline developer may be any alkaline aqueous solution used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline). The alkaline developer may contain a surfactant.
After development, it is preferable to wash the resist pattern with ultrapure water and then remove the substrate and water remaining on the pattern.

When a negative resist pattern is produced from a resist composition, a developer containing an organic solvent (hereinafter, may be referred to as "organic developer") is used as the developer.
Examples of the organic solvent contained in the organic developing solution include a ketone solvent such as 2-hexanone and 2-heptanone; a glycol ether ester solvent such as propylene glycol monomethyl ether acetate; an ester solvent such as butyl acetate; and a glycol such as propylene glycol monomethyl ether. Examples thereof include ether solvents; amide solvents such as N and N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and further preferably substantially only the organic solvent.
As the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially butyl acetate and / or 2 -It is even more preferable that it is only heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a small amount of water.
At the time of development, the development may be stopped by substituting with a solvent of a type different from that of the organic developer.

It is preferable to wash the developed resist pattern with a rinse solution. The rinsing solution is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

<Use>
The resist composition of the present invention 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 ArF. It is suitable as a resist composition for excimer laser exposure and is useful for fine processing of semiconductors.

A more specific description will be given with reference to examples. In the examples, "%" and "part" representing the content or the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography under the following conditions.
Equipment: HLC-8120GPC type (manufactured by Tosoh)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh)
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)

The structure of the compound was confirmed by measuring the molecular peak using mass analysis (LC: Agilent 1100 type, MASS: Agilent LC / MSD type). In the following examples, the value of this molecular peak is indicated by "MASS".

Example 1: Synthesis of salt represented by formula (I-2)
1.00 parts of the compound represented by the formula (I-2-a) and 30 parts of methanol were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 0.93 part of triethylamine was added, 0.74 part of the compound represented by the formula (I-2-b) was added dropwise over 30 minutes, and the mixture was further stirred at 23 ° C. for 18 hours. .. To the obtained reaction mixture, 50 parts of chloroform was added and stirred. To the obtained mixture, 20 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the mixture was separated to remove the organic layer. This operation was repeated 3 times. By concentrating the obtained organic layer, 1.24 parts of the compound represented by the formula (I-2-c) was obtained.
0.97 parts of the compound represented by the formula (I-2-c), 7.50 parts of tetrahydrofuran and 0.28 parts of pyridine were added, and the mixture was stirred at 23 ° C. for 30 minutes and then cooled to 5 ° C. To the obtained mixed solution, 0.40 part of the compound represented by the formula (I-2-d) was added, the temperature was raised to 23 ° C., and the mixture was further stirred at 23 ° C. for 1 hour. To the obtained reaction mixture, 50 parts of chloroform and 2.58 parts of 5% hydrochloric acid were added and stirred, and the mixture was separated to take out the organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the solution was separated to take out the organic layer. To the obtained organic layer, 1.47 parts of a 10% potassium carbonate aqueous solution was added, and the mixture was stirred at 23 ° C. for 30 minutes, separated and the organic layer was taken out. To the obtained organic layer, 20 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the solution was separated to take out the organic layer. This operation was repeated 4 times. By concentrating the obtained organic layer, 0.84 part of the compound represented by the formula (I-2-e) was obtained.
0.80 part of the salt represented by the formula (I-2-f) and 10 parts of chloroform were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 0.15 part of potassium carbonate and 0.03 part of potassium iodide were added, and then 0.70 part of the compound represented by the formula (I-2-e) was added, and the temperature was 23 ° C. Was stirred for 1 hour. To the obtained reaction product, 20 parts of chloroform and 10 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the solution was separated to take out the organic layer. The obtained organic layer was concentrated, and 1.45 parts of acetonitrile and 23.20 parts of ethyl acetate were added to the obtained residue and stirred, and the supernatant was removed. By concentrating the obtained residue, 1.09 parts of a salt represented by the formula (I-2-g) was obtained.
1.09 parts of salt represented by the formula (I-2-g) and 10 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes. To this, 0.33 part of 1% hydrochloric acid was added, and the mixture was stirred at 80 ° C. for 3 hours and concentrated to obtain 0.91 part of the salt represented by the formula (I-2).

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 455.1

Example 2: Synthesis of salt represented by formula (I-3)
4.83 parts of salt represented by the formula (I-3-a) and 30 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes. Then, 1.70 parts of the compound represented by the formula (I-3-b) was added, and the mixture was stirred at 60 ° C. for 1 hour. After filtering the obtained reaction solution, the recovered filtrate was concentrated. To the obtained concentrate, 30 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it was allowed to stand and separated to obtain an organic layer. To the obtained organic layer, 15 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes. This washing operation was performed three more times. 1.00 part of activated carbon was charged into the obtained organic layer, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate is concentrated, 100 parts of tert-butyl methyl ether is added to the obtained concentrate, the mixture is stirred, and then filtered to obtain 4.90 parts of the salt represented by the formula (I-3-c). Obtained.
1.45 parts of the salt represented by the formula (I-3-c), 0.88 parts of the compound represented by the formula (I-3-d) and 30 parts of acetonitrile were added, and further, at 23 ° C. for 6 hours. After stirring, it was filtered. After concentrating the recovered filtrate, 30 parts of chloroform and 15 parts of ion-exchanged water were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated into liquids, and the organic layer was taken out. This operation was repeated 5 times. The obtained organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred to remove the supernatant. By concentrating the obtained residue, 1.48 parts of a salt represented by the formula (I-3-e) was obtained.
1.00 parts of the obtained salt represented by the formula (I-3-e), 10 parts of chloroform and 10 parts of methanol were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 0.04 part of p-toluenesulfonic acid was added, and the mixture was stirred at 60 ° C. for 18 hours. After cooling the obtained reaction product to 23 ° C., 20 parts of chloroform and 10 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, separated and the organic layer was taken out. To the obtained organic layer, 10 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the solution was separated to take out the organic layer. By concentrating the obtained organic layer, 0.62 parts of a salt represented by the formula (I-3) was obtained.

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 485.1

Example 3: Synthesis of salt represented by formula (I-1)
1.00 parts of the salt represented by the formula (I-1-a) and 10 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 0.40 part of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 70 ° C. for 2 hours to be represented by the formula (I-1-c). A solution containing the salt to be added was obtained.
0.71 part of the compound represented by the formula (I-2-c) was added to the solution containing the salt represented by the formula (I-1-c), and the mixture was further stirred at 23 ° C. for 12 hours and then followed. Filtered. After concentrating the recovered filtrate, 30 parts of chloroform and 15 parts of ion-exchanged water were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated into liquids, and the organic layer was taken out. This operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mass was separated into a column (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: chloroform / methanol = 1/1) to formulate (I-1-). 0.22 parts of the salt represented by d) was obtained.
0.20 part of the salt represented by the formula (I-2-g) and 10 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes. 0.06 part of 1% hydrochloric acid was added thereto, and the mixture was stirred at 80 ° C. for 3 hours and concentrated to obtain 0.09 part of the salt represented by the formula (I-1).

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 397.0

Example 4: Synthesis of salt represented by formula (I-26)
0.75 parts of the salt represented by the formula (I-26-a) and 10 parts of chloroform were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 0.15 part of potassium carbonate and 0.03 part of potassium iodide were added, and 0.70 part of the compound represented by the formula (I-2-e) was further added, and the temperature was 23 ° C. Stirred for 1 hour. To the obtained reaction product, 20 parts of chloroform and 10 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the solution was separated to take out the organic layer. The obtained organic layer was concentrated. To the obtained residue, 1 part of acetonitrile and 25 parts of ethyl acetate were added and stirred, and the supernatant was removed. By concentrating the obtained residue, 0.89 parts of a salt represented by the formula (I-26-b) was obtained.
0.50 parts of the salt represented by the formula (I-26-b) and 10 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes. To this, 0.18 parts of 1% hydrochloric acid was added, and the mixture was stirred at 80 ° C. for 3 hours and concentrated to obtain 0.28 parts of a salt represented by the formula (I-26).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 455.1

Synthesis Example 1: Synthesis of salt represented by the formula (B1-5)
50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform were charged into the reactor, and the mixture was stirred at 23 ° C. for 30 minutes. Then, 16.27 parts of the compound represented by the formula (B1-5-b) was added dropwise thereto, and the mixture was stirred at 23 ° C. for 1 hour to obtain a salt represented by the formula (B1-5-c). A containing solution was obtained. To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water were added. The mixture was stirred at 23 ° C. for 12 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. 3.88 parts of activated carbon was added to the obtained chloroform layer, stirred, and filtered. The recovered filtrate was concentrated, and 125.87 parts of acetonitrile was added to the obtained residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added, and the mixture was stirred at 23 ° C. for 30 minutes to remove the supernatant and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of a salt represented by the formula (B1-5).

MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (-) Spectrum): M ^- 339.1

Synthesis Example 2 [Synthesis of salt represented by formula (B1-21)]

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

20.00 parts of the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. ..
To the obtained mixed solution, 0.21 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 1 hour. The obtained reaction solution was concentrated. To the obtained residue, 200 parts of chloroform and 50 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. 50 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated to remove the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated. The obtained residue is dissolved in 53.51 parts of acetonitrile, concentrated, added 113.05 parts of tert-butyl methyl ether, stirred, and filtered to obtain a salt 10 represented by the formula (B1-21). Obtained .47 copies.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 339.1

Synthesis Example 3 [Synthesis of salt represented by formula (B1-22)]
11.26 parts of salt represented by the formula (B1-22-a), 10.00 parts of the compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged and 23 ° C. Was stirred for 15 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out, and 15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer is concentrated, 50 parts of tert-butyl methyl ether is added to the obtained residue, the mixture is stirred at 23 ° C. for 30 minutes, and filtered to obtain a salt represented by the formula (B1-22-c). We got 75 copies.

11.71 parts of the salt represented by the formula (B1-22-c), 1.70 parts of the compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged and charged at 23 ° C. for 30 minutes. Stirred. To the obtained mixed solution, 0.12 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated. To the obtained residue, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. 12.50 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. This washing operation was repeated 8 times. The obtained organic layer was concentrated. To the obtained residue, 50 parts of tert-butyl methyl ether was added, stirred, and filtered to obtain 6.84 parts of a salt represented by the formula (B1-22).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

Synthesis of Resin (A) The compounds (monomers) used for the synthesis of resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomer (a1-1-2)" or the like according to the formula number.

Synthesis Example 4 [Synthesis of resin A1]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1) and a monomer (a3-4-2) are used, and the molar ratio [monomer (a1-1-1)] is used. -3): Monomer (a1-2-9): Monomer (a2-1-1): Monomer (a3-4-2)] are mixed so as to be 45: 14: 2.5: 38.5. A solution was prepared by adding propylene glycol monomethyl ether acetate 1.5% by mass of the total amount of monomers. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to this solution in an amount of 1 mol% and 3 mol%, respectively, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin is dissolved again in propylene glycol monomethyl ether acetate, and the obtained solution is poured into a mixed solvent of methanol / water to precipitate the resin, and the resin is filtered. resin A1 of molecular weight 7.9 × 10 ³ (copolymer) was obtained in 70% yield. This resin A1 has the following structural units.

Synthesis Example 5 [Synthesis of resin X1]
As the monomer, a monomer (a5-1-1) and a monomer (a4-0-12) are used, and the molar ratio [monomer (a5-1-1): monomer (a4-0-12)] is 50:50. Methyl isobutyl ketone was added in an amount 1.2% by mass of the total amount of the monomers to prepare a solution. Azobis (2,4-dimethylvaleronitrile) as an initiator was added to this solution in an amount of 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The reaction mixture obtained, the resin was precipitated by pouring into a large amount of methanol / water mixed solvent, the resin was filtered, the weight-average molecular weight 1.0 × 10 ⁴ of the resin X1 (copolymer) to yield 91% I got it in. This resin X1 has the following structural units.

(Preparation of resist composition)
Each of the components shown below was mixed by the mass part shown in Table 2 and dissolved in a solvent, and then filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin (A)>
A1, X1: Resin A1, Resin X1
<Acid generator (B)>
I-1: Salt represented by the formula (I-1) I-2: Salt represented by the formula (I-2) I-3: Salt represented by the formula (I-3) I-26: Formula Salt represented by (I-26) I0-1: Synthesized according to Examples of JP-A-2011-46694
B1-5: Salt represented by the formula (B1-5) B1-21: Salt represented by the formula (B1-21) B1-22: Salt represented by the formula (B1-22) B1-X: Special Synthesized according to the examples of Kai 2012-229206
<Weak acid intramolecular salt (D)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)
<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-Heptanone 20 parts γ-butyrolactone 3.5 parts

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

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

<CD uniformity (CDU) evaluation>
In the effective sensitivity, the hole diameter of the pattern formed by the mask having a hole diameter of 55 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was calculated by measuring the average hole diameter of a pattern formed by a mask with a hole diameter of 70 nm at 400 points on the same wafer as a population.
"○" when the standard deviation is 2.00 nm or less,
When the standard deviation was larger than 2.00 nm, it was judged as “x”.
The results are shown in Table 3. The numbers in parentheses indicate the standard deviation (nm).

From the above results, it can be seen that the salt, acid generator of the present invention and the resist composition using the same can produce a resist pattern with good CD uniformity.

The salt, acid generator of the present invention and the resist composition using the same are suitable for microfabrication of semiconductors because they are excellent in CD uniformity of the obtained resist pattern.

Claims (6)

A salt represented by the formula (I).
[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Ad represents an adamantane triyl group.
Z ⁺ represents an organic cation. ] The salt according to claim 1, wherein L ^b1 is a group represented by any of the formulas (b1-1) to (b1-3), and * represents a binding site with CQ ¹ Q ² .
[In equation (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 hydrocarbon group may be substituted. 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 equation (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 hydrocarbon group may be substituted. 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 equation (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 hydrocarbon group may be substituted. 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. ] An acid generator containing the salt according to claim 1 or 2 as an active ingredient. A resist composition containing the acid generator according to claim 3 and a resin having an acid unstable group . The resist composition of claim 4 containing salt capable of generating a weak acid acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to claim 4 or 5 onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) 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.