JP6650249B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

Patent Document 1 describes a resist composition containing a resin (A1X-1) comprising a combination of the following structural units, a resin (A2X-1) comprising a combination of the following structural units, and an acid generator. I have.

Patent Document 2 discloses a resist composition containing a resin (A1X-2) composed of a combination of the following structural units, a resin (A2X-2) composed of a combination of the following structural units, and an acid generator. I have.

JP 2008-274143 A JP 2012-8500 A

  In the above resist composition, the defect and the line edge roughness (LER) may not always be satisfied.

The present invention includes the following inventions.
[1] a resin (A1) having a group represented by the formula (a4-x),
A resin (A2) having two or more acid labile groups represented by group (1) and / or group (2), and
A resist composition containing an acid generator.
[In the formula (a4-5),
n represents 0 or 1.
R ⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms and a fluorine atom.
* Represents a bond. ]
[In equation (1),
Which R ^a1, R ^a2 and a R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or a group composed of a combination of these 3 to 20 carbon atoms, R ^a1 and R ^a2 Combine with each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]
[In equation (2),
R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms;
R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocyclic ring having 3 to 20 carbon atoms together with X and the carbon atom to which they are bonded. And —CH ₂ — contained in the hydrocarbon group and the divalent heterocycle may be replaced by —O— or —S—.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

[2] The structural unit having a group represented by the formula (a4-x) is a structural unit represented by the formula (a4-5) or a structural unit represented by the formula (a4-6) [1] The resist composition according to the above.
[In the formula (a4-5),
R ⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms and a fluorine atom.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ represents a single bond or ^{* -L 2 -X 51 - (L} 3 -X 52) g - representing the. * Represents a bond to an oxygen atom.
L ² and L ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ⁵¹ and X ⁵² each independently represent —O— or ** — CO—O—. ** represents a bond to L ² or L ³ .
g represents 0 or 1. ]
[In the formula (a4-6),
R ⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms and a fluorine atom.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ represents a single bond or ^{* -A 2 -X 61 - (A} 3 -X 62) h - represents a. * Represents a bond to an oxygen atom.
A ² and A ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ⁶¹ and X ⁶² are each independently, -O -, - CO-O- or an -O-CO-.
h represents 0 or 1.
W ¹ represents a divalent alicyclic hydrocarbon group having 5 to 18 carbon atoms. ]
[3] The resist composition according to [1] or [2], wherein the resin (A1) further contains a structural unit represented by the formula (a5).
[In the formula (a5),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. You may. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁴ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁴ 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 by an oxygen atom or a carbonyl group. ]
[4] The resist composition according to [3], wherein R ² is an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms.

[5] The resin according to any one of [1] to [4], wherein the resin (A2) is a resin containing a structural unit represented by the formula (a1-1) or a structural unit represented by the formula (a1-2). The resist composition as described in the above.
[In the formulas (a1-1) and (a1-2),
L ^a1 and L ^a2 each independently, -O- or _{^{* -O- (CH 2) k1 -CO}} -O- the stands, k1 represents an integer of 1-7, * the binding of -CO- Represent hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents an integer of 0 to 14.
n1 represents the integer of 0-10.
n1 'represents the integer of 0-3. ]

[6] The resist composition according to any one of [1] to [5], wherein the acid generator is a salt represented by the formula (B1).
[In the formula (B1),
Q ¹ And Q ^Two Represents a fluorine atom or a C1-C6 perfluoroalkyl group each independently.
L ^b1 Represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH contained in the divalent saturated hydrocarbon group _Two -May be replaced by -O- or -CO-, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; Group and the -CH contained in the monovalent alicyclic hydrocarbon group _Two -Is -O-, -SO _Two -Or -CO-.
Z ⁺ Represents an organic cation. ]
[7] The resist composition according to any one of [1] to [6], further comprising a salt having a lower acidity than the acid generated from the acid generator.
[8] (1) a step of applying the resist composition according to any one of [1] to [7] on a substrate,
(2) drying the composition after application to form a composition layer;
(3) exposing the composition layer to light,
(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 comprising:

  According to the resist composition of the present invention, it is possible to produce a resist pattern with few defects and excellent line edge roughness (LER).

  In the present specification, unless otherwise specified, in the description of the structural formula of a compound, “aliphatic hydrocarbon group” means a linear or branched hydrocarbon group, and “alicyclic hydrocarbon group” means an aliphatic hydrocarbon group. It means a group obtained by removing a number of hydrogen atoms corresponding to a valence from a ring of a cyclic hydrocarbon. 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, "(meth) acrylic monomer" means at least one monomer having a "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of I do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively. In addition, any of the groups described in this specification that can have both a linear structure and a branched structure may be used.

<Resist composition>
The resist composition of the present invention,
Resin (hereinafter sometimes referred to as “resin (A)”);
An acid generator (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition of the present invention preferably further contains a solvent (hereinafter sometimes referred to as “solvent (E)”).
The resist composition of the present invention preferably further contains a quencher (hereinafter sometimes referred to as “quencher (C)”).
The resist composition of the present invention preferably further contains a salt having a weak acidity such as a weak acid inner salt (hereinafter sometimes referred to as “weak acid inner salt (D)”).

<Resin (A)>
Resin (A)
A resin having a group represented by the formula (a4-x) (hereinafter sometimes referred to as “resin (A1)”);
It includes a resin having two or more acid labile groups represented by the group (1) and / or the group (2) (hereinafter sometimes referred to as “resin (A2)”).
As used herein, the term “acid-labile group” refers to a group that has a leaving group and forms a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group upon contact with an acid. Means
Further, the resin (A) may include a resin other than the resin (A1) and the resin (A2) (hereinafter, may be referred to as “resin (X)”) as described later.

<Resin (A1)>
The resin (A1) has a group represented by the following formula (a4-x). The resin (A1) preferably does not have a polar group such as a hydroxyl group and a carboxyl group.

<Structural unit (a4-x)>
The resin (A1) contains a structural unit having a group represented by the formula (a4-x) (hereinafter, may be referred to as “structural unit (a4-x)”).
[In the formula (a4-x),
n represents 0 or 1.
R ⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms and a fluorine atom.
* Represents a bond. ]

Examples of the saturated hydrocarbon group having a fluorine atom of R ⁴ include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -2,2 , 2-trifluoroethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1, 2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro ) Methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, 2 -(Perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5 Fluorinated alkyl groups such as perfluorocyclohexyl group and perfluoroadamantyl group; and alicyclic hydrocarbon groups having a fluorine atom such as perfluorocyclohexyl group and perfluoroadamantyl group. .

Examples of the group represented by the formula (a4-x) include the following. * Represents a bond.

  The structural unit (a4-x) is preferably a structural unit represented by the formula (a4-5) or a structural unit represented by the formula (a4-6).

[In the formula (a4-5),
R ⁴ has the same meaning as described above.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ represents a single bond or ^{* -L 2 -X 51 - (L} 3 -X 52) g - representing the. * Represents a bond to an oxygen atom.
L ² and L ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ⁵¹ and X ⁵² each independently represent —O— or ** — CO—O—. ** represents a bond to L ² or L ³ .
g represents 0 or 1. ]
[In formula (a4-6), R ³ , R ⁴ and n represent the same meaning as described above.
A ¹ represents a single bond or ^{* -A 2 -X 61 - (A} 3 -X 62) h - represents a. * Represents a bond to an oxygen atom.
A ² and A ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ⁶¹ and X ⁶² are each independently, -O -, - CO-O- or an -O-CO-.
h represents 0 or 1.
W ¹ represents a divalent alicyclic hydrocarbon group having 5 to 18 carbon atoms. ]

Examples of the alkyl group for R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. Preferably, it is a C1-C4 alkyl group, More preferably, it is a methyl group and an ethyl group.
Examples of the halogen atom for R ³ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group having a halogen atom of R ³ include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluoropentyl group. Examples include a hexyl group, a perchloromethyl group, a perbromomethyl group and a periodomethyl group.
R ³ is preferably a hydrogen atom or a methyl group.

Examples of the alkanediyl group having 1 to 6 carbon atoms of L ² , L ³ , A ² and A ³ include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane- A linear alkanediyl group such as a 1,5-diyl group and a hexane-1,6-diyl group, or a linear alkanediyl group may have an alkyl group (particularly, an alkyl group having 1 to 4 carbon atoms, a methyl group, Those having a side chain of ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, etc., ethane-1,1-diyl group, propane-1,2-diyl group, butane -1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl Branched alkanediyl groups such as I can do it.
L ² , L ³ , A ² and A ³ are preferably a divalent alkanediyl group having 1 to 3 carbon atoms, more preferably a methylene group or an ethylene group.

^{* -L 2 -X 51 - (L} 3 -X 52) g - ^{The, * -L 2 -O-, * -L} 2 -CO-O-, * -L 2 -CO-O-L 3 - ^{CO-O-, * -L 2 -O} -L 3 -CO-O- and the like. Among ^{them, * -L 2 -O-, * -L} 2 -CO-O- or ^{* -L 2 -CO-O-L} 3 -CO-O- are preferable.

^{* -A 2 -X 61 - (A} 3 -X 62) h - ^{The, * -A 2 -O-, 2 -CO} -O- * -A, -O-CO- * -A 2, * - ^{A 2 -CO-O-A 3} -CO-O-, * -A 2 -O-CO-A 3 -O-, 3 -CO-O- * -A 2 -O-A, * -A 2 - ^{CO-O-A 3 -O-} CO-, * -A 3 -O-CO- 2 -O-CO-A, and the like. Among ^{them, * -A 2 -O-, * -A} 2 -CO-O-, * -A 2 -CO-O-A 3 -CO-O- or ^* -A ² -O-A ³ -CO- O- is preferred.

L ¹ is preferably a single bond or ^* —L ² —CO—O—, more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—. , A single bond or —CH ₂ —CO—O—.
A ¹ is preferably a single bond or ^* -A ² -CO-O- in which a single bond, more preferably -CH ₂ -CO-O- or -C ₂ H ₄ -CO-O- in which , A single bond or —CH ₂ —CO—O—.

Examples of the divalent alicyclic hydrocarbon group having 5 to 18 carbon atoms for W ¹ include a cyclopentanediyl group, a cyclohexanediyl group, an adamantanediyl group, and a norbornanediyl group. Among them, a cyclohexanediyl group and an adamantanediyl group are preferred, and an adamantanediyl group is more preferred.

The adamantanediyl group is preferably a divalent group represented by any one of formulas (Ad-1) to (Ad-3), and is represented by formula (Ad-1) or formula (Ad-2). And more preferably a divalent group represented by the formula (Ad-1). * Represents a bond.

Examples of the structural unit represented by the formula (a4-5) include a structural unit represented by the following formula.

The structural unit represented by the formula (a4-6) includes, for example, a structural unit represented by the following formula.
In the formulas (a4-6-11) and (a4-6-12), the structural unit (a4-5) also includes a structural unit in which a methyl group directly connected to the main chain is replaced by a hydrogen atom.

The structural unit (a4-5) is derived from a compound represented by the formula (a4-5) (hereinafter, may be referred to as “compound (a4-5)”).
[In the formula (a4-5), R ³ , R ⁴ and L ¹ represent the same meaning as described above. ]

Compound (a4-5) is obtained by reacting a compound represented by the formula (a4-5-a) with a compound represented by the formula (a4-5-b) in a solvent in the presence of a catalyst. Obtainable.
Examples of the solvent include dimethylformamide.
Examples of the catalyst include potassium carbonate and potassium iodide.
Examples of the compound represented by the formula (a4-5-a) include a salt represented by the following formula, which can be easily obtained from the market.
Examples of the compound represented by the formula (a4-5-b) include a salt represented by the following formula, which can be easily obtained from the market.

The structural unit (a4-6) is derived from a compound represented by the formula (a4-6) (hereinafter, may be referred to as “compound (a4-6)”).
[In the formula (a4-6), R ³ , R ⁴ , A ¹ , W ¹ and n represent the same meaning as described above. ]

The compound (a4-6) is obtained by, for example, reacting a compound represented by the formula (a4-6-a) with a compound represented by the formula (a4-6-b) in the presence of a catalyst in a solvent. Can be obtained.
Examples of the solvent include dimethylformamide.
Examples of the catalyst include potassium carbonate and potassium iodide.
Examples of the compound represented by the formula (a4-6-a) include a salt represented by the following formula, which can be easily obtained from the market.
Examples of the compound represented by the formula (a4-6-b) include a salt represented by the following formula, which can be easily obtained from the market.

The resin (A1) is a group represented by the formula (a4-x), for example, a resin having no polar group in addition to the structural unit (a4-5) or the structural unit (a4-6), A structural unit other than the structural unit (a4-5) and the structural unit (a4-6) may be included.
Examples of such a structural unit include a structural unit having a fluorine atom (hereinafter, may be referred to as “structural unit (a4)”) and a structural unit having a non-eliminable hydrocarbon group (hereinafter, referred to as “structural unit (a5)”). In some cases) and structural units derived from monomers known in the art.
When the resin (A1) includes a structural unit other than the structural unit (a4-5) and the structural unit (a4-6), the resin (A1) preferably includes the structural unit (a5).

  The content of the structural unit (a4-x) in the resin (A1) is preferably from 10 to 100 mol%, more preferably from 20 to 100 mol%, and even more preferably from 30 to 100 mol%, based on all structural units of the resin (A1). Mole% is more preferred.

  The structural unit (a4-x) constituting the resin (A1) is known by combining only one kind or a combination of two or more kinds, and optionally, combining one or more kinds of monomers having no polar group described later. (For example, a radical polymerization method).

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

The perfluoro alkanediyl group L ^5, difluoromethylene group, a perfluoroalkyl ethylene group, perfluoroethyl fluoro methylene group, perfluoro-1,3-diyl group, perfluoro-1,2-diyl group, 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, Examples include a 3-diyl group and a perfluorooctane-4,4-diyl group.
The perfluorocycloalkanes diyl group L ^5, perfluoro-cyclohexane diyl group, perfluoro cyclopentanediyl group, perfluoro cycloheptane-diyl group, a perfluoroalkyl adamantane-diyl group and the like.

Examples of the aliphatic saturated hydrocarbon group for L ⁶ include an alkanediyl group having 1 to 4 carbon atoms, such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group. Linear alkanediyl group, such as those having a side chain of an alkyl group (among others, methyl group, ethyl group, etc.), ethane-1,1-diyl group, propane-1, And branched alkanediyl groups such as a 2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group.
L ⁶ is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ⁵ is preferably a C 1-6 perfluoroalkanediyl group, more preferably a C 1-3 perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include the following.

In the above structural unit, a structural unit in which the methyl group corresponding to R ⁵ is replaced by a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-0).

Examples of the structural unit (a4) include a structural unit represented by the formula (a4-1).
[In the formula (a4-1),
^Ra41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms that may have a substituent, -CH ₂ contained in the hydrocarbon group - can be replaced by -O- or -CO- Good.
However, at least one of A ^a41 and R ^a42 is a group having a halogen atom as a substituent.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1).
[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
X ^a41 and X ^a42 each independently represent -O-, -CO-, ^-CO -O-, or -O-CO-.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* Is a bond with -O-CO- ^Ra42 . ]

^Examples of the hydrocarbon group of ^Ra42 include a chain or cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the linear aliphatic hydrocarbon group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, and hexyldecyl. , A heptadecyl group and an octadecyl group. Examples of the cyclic aliphatic hydrocarbon group include a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* And a polycyclic alicyclic hydrocarbon group.
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.

^As the hydrocarbon group for R ^a42 , a chain or cyclic aliphatic hydrocarbon group and a group formed by combining these are preferable, and a carbon-carbon unsaturated bond may be included. And a cyclic aliphatic saturated hydrocarbon group and a group formed by combining them. Specific examples include an aliphatic hydrocarbon group, an alkyl group, an alicyclic hydrocarbon group, and a combination thereof.
R ^a42 includes, as a substituent, a halogen atom or a group represented by the formula (a-g3), preferably an aliphatic hydrocarbon group ^optionally having a halogen atom, and an alkyl group having a halogen atom and / or Or an aliphatic hydrocarbon group having a group represented by the formula (a-g3) is more preferable.
[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.
* Represents a bond. ]

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.
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 the number of carbon atoms is A perfluoroalkyl group having 1 to 6 carbon atoms, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When ^Ra42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), the aliphatic hydrocarbon group includes the number of carbon atoms contained in the group represented by the formula (a-g3). The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably one.

The aliphatic hydrocarbon group having a group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).
[In the formula (a-g2),
A ^a46 represents an aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond to the carbonyl group. ]

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

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

^Examples of the alkanediyl group for A ^a41 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, 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, Examples include a branched alkanediyl group such as a 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

The aliphatic hydrocarbon group of A ^a42 , A ^a43 and A ^{a44 in} the group (a-g1) may have a carbon-carbon unsaturated bond, but is preferably an aliphatic saturated hydrocarbon group. Examples of the aliphatic saturated hydrocarbon group include an alkyl group (the alkyl group may be linear or branched) and an alicyclic hydrocarbon group, and a combination of an alkyl group and an alicyclic hydrocarbon group. Examples include the aliphatic hydrocarbon group formed.
Examples of the aliphatic hydrocarbon group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a 1-methylpropane-1,3- A diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, and the like.
^Examples of the substituent of the alkanediyl group for A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

^Examples of the group (a-g1) in which X ^a42 is an oxygen atom include the following groups. In the following examples, the * on the right side of the two bonds represented by * is a bond to -O-CO- ^Ra42 .

Examples of the group (a-g1) in which X ^a42 is a carbonyl group include the following groups.

Examples of the group (a-g1) in which X ^a42 is a carbonyloxy group include the following groups.

Examples of the group (a-g1) in which X ^a42 is an oxycarbonyl group include the following groups.

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

^Examples of the alkanediyl group for A ^f1 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Linear alkanediyl groups such as hexane-1,6-diyl group and the like; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 And a branched alkanediyl group 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.
Examples of the alkyl group include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. .
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group. And cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, a norbornyl group, Examples include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include 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, , 1,2,2-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 1,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl 2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2 , 2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, 2- (perfluoro Butyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5 And a fluorinated alkyl group such as a 6,6-dodecafluorohexyl group, a perfluoropentylmethyl group and a perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a fluoroalkyl group such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

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

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

The alkanediyl group A ^f11, include the same groups as alkanediyl groups A ^f1.

The aliphatic hydrocarbon group of ^Af13 includes any of a chain type and a cyclic type, and a divalent aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group ^optionally having a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group optionally having a fluorine atom, and more preferably a perfluoroalkanediyl group.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene And perfluoroalkanediyl groups such as a perfluoropropanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic divalent aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

The aliphatic hydrocarbon group for ^Af14 includes any of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining them. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Examples of the chain aliphatic hydrocarbon group which may have a fluorine atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl, butyl, perfluoropentyl, 1,1,1,2,2,3,3,4,4-nonafluoropentyl, pentyl, hexyl, perfluorohexyl, Examples 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 a monocyclic or polycyclic group. 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 for ^Af13 preferably has 1 to 6 carbon atoms, and more preferably 2 to 3 carbon atoms.
Aliphatic hydrocarbon group A ^f14 is preferably 3 to 12 carbon atoms, more preferably from 3 to 10. Among them, ^Af14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

Examples of the structural unit represented by the formula (a4-2) include structural units represented by the formulas (a4-1-1) to (a4-1-22).

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

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

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same as the hydrocarbon group of R ^f2 in 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 3 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom. Preferably, an alkyl group having 1 to 6 carbon atoms having a fluorine atom is more preferable.

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

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

  When the resin (A1) has the structural unit (a4), its content is preferably from 5 to 70 mol%, more preferably from 10 to 60 mol%, based on all the structural units of the resin (A1). ~ 50 mol% is more preferred.

<Structural unit (a5)>
The non-eliminated hydrocarbon group contained in the structural unit (a5) is represented by the following.
[In the formula (a5),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. You may. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁴ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁴ 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 by an oxygen atom or a carbonyl group. ]

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

Examples of the divalent saturated hydrocarbon group for L ⁴ include an aliphatic saturated hydrocarbon group and an alicyclic saturated hydrocarbon group, and are preferably a divalent aliphatic saturated hydrocarbon group. Examples of the divalent aliphatic saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

Examples of the group in which the methylene group contained in the saturated hydrocarbon group is replaced by an oxygen atom or a carbonyl group include groups represented by formulas (L1-1) to (L1-4). In the following formula, * represents a bond with -O-.
In the formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In the formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
^Lx4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 17 or less.
In the formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.
In the formula (L1-4),
L ^x8 and L ^{x9 each} represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
^Lx4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
^Lx7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
^Lx8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

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

L ⁴ is preferably a single bond, a methylene group, an ethylene group or a group represented by the formula (L1-1).

Among them, the structural unit (a5) includes the structural units described below.

In Formulas (a5-1-1) to (a5-1-18), structural units in which the methyl group corresponding to R ¹ is replaced by a hydrogen atom can also be mentioned as specific examples of the structural unit (a5).

When the resin (A1) contains the structural unit (a5), the content of the structural unit (a5) is preferably from 20 to 90 mol%, more preferably from 30 to 80 mol%, based on all the structural units of the resin (A1). Is more preferable, and 40 to 70 mol% is further preferable.
When the content of the structural unit having the group represented by the formula (a4-x) and the content of the structural unit (a5) are within the above ranges, a resist pattern having excellent line edge roughness can be produced, and in particular, a defect pattern can be obtained. A resist pattern with less occurrence can be manufactured.

  The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 7,000 or more, further preferably 10,000 or more), and 80,000 or less (more preferably 50,000 or less, further more preferably). Is 30,000 or less). The weight average molecular weight is determined by gel permeation chromatography analysis as a standard polystyrene standard conversion value, and detailed analysis conditions for the analysis will be described in detail in Examples of the present application.

<Resin (A2)>
Resin (A2) is a resin having two or more acid labile groups. The acid labile group is derived from a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”). The resin (A2) includes, as structural units other than the structural unit (a), structural units having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) and other structural units (hereinafter referred to as “structural unit (s)”). Unit (t) ”).
<Structural unit (a)>
The structural unit (a) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a)”). Examples of the acid labile group contained in the structural unit (a) include acid labile groups represented by the following groups (1) and / or (2).
[In formula (1), R ^{a1 to} R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group obtained by combining them; ^a1 and ^Ra2 bond to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]
[In formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. Or R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocycle having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and are included in the hydrocarbon group and the divalent heterocycle. more -CH ₂ - may be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

The alkyl group of R ^a1 to R ^a3, methyl group, ethyl group, propyl group, n- butyl group, n- pentyl group, n- hexyl, n- heptyl, n- octyl group.
The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cycloalkyl group 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 (* represents a bond). Alicyclic hydrocarbon groups R ^a1 to R ^a3 is preferably 3 to 16 carbon atoms.
Examples of a group obtained by combining an alkyl group and an alicyclic hydrocarbon group include, for example, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a methyladamantyl group, a cyclohexylmethyl group, an adamantylmethyl group, and a norbornyl group. And an ethyl group.
na is preferably 0.

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

Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as those described above.
Examples of the aromatic hydrocarbon group include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, and biphenyl. And aryl groups such as phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.

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 an alkyl group in the formula (1), and preferably a tert-butoxycarbonyl group); 2-alkyladamantan-2-yloxycarbonyl group (in the 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- ( Adamantane-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), a group in which R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group).

^{Examples of the} bivalent heterocyclic group formed by R ^{a2 ′} and R ^{a3 ′} bonded together with the carbon atom to which they are bonded and X include the following groups. * Represents a bond.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

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

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. When a resin (A2) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used for a resist composition, the resolution of a resist pattern can be improved.

  In the resin (A2), the content of the structural unit (a) is preferably 30 to 90 mol%, more preferably 35 to 85 mol%, based on all structural units of the resin (A2). Preferably it is 40 to 80 mol%.

  As the structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1), preferably, the structural unit represented by the formula (a1-0) or the formula (a1-1) Examples 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 respectively referred to as a structural unit (a1 -0), a structural unit (a1-1) and a structural unit (a1-2), a monomer for deriving the structural unit (a1-0), a monomer for deriving the structural unit (a1-1), and a structural unit (a1- The monomers that induce 2) may be referred to as monomer (a1-0), monomer (a1-1), and monomer (a1-2), respectively.

[In the formula (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 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof. ]

[In the formulas (a1-1) and (a1-2),
L ^a1 and L ^a2 each independently, -O- or _{^{* -O- (CH 2) k1 -CO}} -O- the stands, k1 represents an integer of 1-7, * the binding of -CO- Represent hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents an integer of 0 to 14.
n1 represents the integer of 0-10.
n1 'represents the integer of 0-3. ]

L ^a01 is preferably an oxygen atom or ^* —O— (CH ₂ ) _k01 —CO—O— (k01 is an integer of 1 to 4, more preferably 1), more preferably an oxygen atom is there.
Examples of the alkyl group of R ^a02 , R ^a03 and R ^a04 , the alicyclic hydrocarbon group, and the combination thereof include the same groups as the groups described for R ^{a1 to} R ^a3 in formula (1).
Alkyl group R ^a02, R ^a03 and R ^a04 are preferably not more than 6 carbon atoms.
The alicyclic hydrocarbon group of ^Ra02 , ^Ra03 and ^Ra04 preferably has 8 or less carbon atoms, more preferably 6 or less carbon atoms.
The group obtained by combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less obtained by combining the alkyl group and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
^Ra02 and ^Ra03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group.
^Ra04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

L ^a1 and L ^a2 is preferably, -O- or _{^{* -O- (CH 2) k1 '}} -CO-O- , more preferably an is -O-. k1 ′ is an integer of 1 to 4, and is preferably 1.
R ^a4 and R ^a5 are preferably a methyl group.
Examples of the alkyl group, alicyclic hydrocarbon group and the combination thereof of R ^a6 and R ^a7 include the same groups as those described for R ^{a1 to} R ^a3 in formula (1).
The alkyl group of ^Ra6 and ^Ra7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of ^Ra6 and ^Ra7 preferably has 8 or less carbon atoms, more preferably 6 or less carbon atoms.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

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

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

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

Examples of the monomer (a1-2) include 1-methylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclopentan-1-yl (meth) acrylate, 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-isopropylcyclopentan-1-yl (Meth) acrylate, 1-isopropylcyclohexane-1-yl (meth) acrylate, and the like. A monomer represented by any of the formulas (a1-2-1) to (a1-2-12) is preferable, and the monomers represented by the formulas (a1-2-3), (a1-2-4) and (a1-2-4) are preferable. 2-9) or a monomer represented by the formula (a1-2-10) is more preferable, and a monomer represented by the formula (a1-2-3) or the formula (a1-2-9) is further preferable.

  When the resin (A2) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is determined by the total structure of the resin (A2). It is usually from 10 to 95 mol%, preferably from 15 to 90 mol%, more preferably from 20 to 85 mol%, based on the unit.

Furthermore, the structural unit (a) having the group (1) also includes a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Further, the monomer for deriving the structural unit (a1-3) may be referred to as a monomer (a1-3).
In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group 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 them; A hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and -CH _2- contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is -O- Or it may be replaced by -CO-.
R ^a10 , R ^a11 and R ^a12 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining them; ^a10 and ^Ra11 combine with each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the carbon atom to which they are attached.

Here, -COOR ^a13 is, 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 for R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms of ^Ra13 include 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 a -Hexyl group, n-heptyl group, 2-ethylhexyl group, n-octyl group and the like.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms for Ra13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, a 2-oxo-oxolane-3-. An yl group and a 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group of R ^{a10 to} R ^a12 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, Examples 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 monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl, cyclobutyl, and cyclopentyl. And a cycloalkyl group such as 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 decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl Group, methylnorbornyl group, isobornyl group and the like.
In the case where ^Ra10 and ^Ra11 are bonded to each other to form a divalent hydrocarbon group together with the carbon atom to which they are bonded, -C ( ^Ra10 ) ( ^Ra11 ) ( ^Ra12 ) is as follows. Groups are preferred.

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

  Since the resin (A) containing the structural unit (a1-3) contains a sterically bulky structural unit, the resin (A) containing the structural unit (a1-3) 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 (A2) includes the structural unit (a1-3), its content is preferably from 10 to 95 mol%, more preferably from 15 to 90 mol%, based on all structural units of the resin (A2). 20-85 mol% is more preferred.

As the structural unit (a) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). No.
[In the formula (a1-4),
^Ra32 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 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
la represents the integer of 0-4. When la is 2 or more, a plurality of ^Ra33 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 To form a divalent heterocycle having 3 to 20 carbon atoms together with C—O to which they are bonded, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocycle is —O— or — It may be replaced by S-. ]

The alkyl group of R ^a32 and R ^a33, methyl, ethyl, propyl, isopropyl, butyl, pentyl, and hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom of R ^a32 and R ^a33, 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 a 1,1,2,2-tetrafluoro group. 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, butyl, perfluoropentyl, 1,1,1,2,2,3,3,4,4-nonafluoropentyl, n-pentyl, n-hexyl, n-perfluorohexyl, etc. No.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the 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, and a butyryloxy group.
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 alkyl groups having 1 to 18 carbon atoms, alicyclic hydrocarbon group having 3 to 18 carbon atoms, a group formed by combining these or aromatic hydrocarbon group having 6 to 18 carbon atoms It is.

In the formula (a1-4), R ^a32 is preferably a hydrogen atom.
^Ra33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, and more preferably 0.
^Ra34 is preferably a hydrogen atom.
^Ra35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a methyl group or an ethyl group.
The hydrocarbon group of ^Ra36 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 formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group for R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group for ^Ra36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

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

  When the resin (A2) has a structural unit (a1-4), its content is preferably from 10 to 95 mol%, more preferably from 15 to 90 mol%, based on all structural units of the resin (A2). And 20 to 85 mol% is more preferable.

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

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.
L ⁵² and L ⁵³ is preferably is -O-, and the other the other is -S-.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 represents a single bond or * -CH ₂ -CO-O- are preferable. * Represents a bond to L ^51.

Examples of the monomer that leads to the structural unit (a1-5) include monomers described in JP-A-2010-61117. Above all, monomers represented by the formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by the formula (a1-5-1) or the formula (a1-5-2) are preferable. Is more preferred.

  When the resin (A2) has the structural unit (a1-5), its content is preferably from 1 to 50 mol%, more preferably from 3 to 45 mol%, based on all structural units of the resin (A2). , 5 to 40 mol% is more preferred.

  The structural unit (a) having an acid labile group in the resin (A2) includes a structural unit (a1-0), a structural unit (a1-1), a structural unit (a1-2), and a structural unit (a1-5). Or a combination of the structural unit (a1-1) and the structural unit (a1-5); a combination of the structural unit (a1-1) and the structural unit (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 structural unit (a1-0) ), Structural unit (a1-0), structural unit (a1-1) and structural unit (a1-2), structural unit (a1-1), structural unit (a1-2) and structural unit (a1). -5) is more preferable. The combination of the unit (a1-1) and the structural unit (a1-2) is more preferred.

<Structural unit (s)>
The structural unit (s) having no acid labile group is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). As the monomer (s), a monomer having no acid labile 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 having no acid labile group is preferable. Structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or having a lactone ring and having no acid labile group Use of a resin having units (hereinafter sometimes referred to as “structural unit (a3)”) in the resist composition of the present invention can improve the resolution of a resist pattern and the adhesion to a substrate.

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

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

^Examples of the alkyl group for ^Ra30 include a methyl group, an ethyl group, a propyl group, a butyl group, an n-pentyl group, and an n-hexyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group having 1 to 6 carbon atoms that may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group, n -Perfluorohexyl group and the like. ^Ra30 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.
^Examples of the alkoxy group for ^Ra31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the 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, and a butyryloxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0.

Examples of the monomer for deriving the structural unit (a2-0) include 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 one represented by the formula (a2-0-1) or the formula (a2-0-2) is more preferable.

  The resin (A2) containing the structural unit (a2-0) is subjected to a polymerization reaction using a monomer obtained by protecting a phenolic hydroxy group of a monomer for deriving the structural unit (a2-0) with a protecting group, and then deprotected. It can be manufactured by processing. However, when performing the deprotection treatment, it is necessary to perform the deprotection treatment so as not to significantly impair the acid labile group contained in the structural unit (a). Examples of such a protecting group include an acetyl group.

  When the resin (A2) has the structural unit (a2-0) having a phenolic hydroxy group, its content is preferably from 5 to 95 mol%, more preferably from 10 to 95 mol%, based on all structural units of the resin (A2). 80 mol% is more preferable, and 15 to 80 mol% is still 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 the formula (a2-1),
L ^a3 is, -O- or ^* -O- (CH _{2) k2} represents a -CO-O-.
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is -O-.
R ^a14 is preferably a methyl group.
^Ra15 is preferably a hydrogen atom.
^Ra16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

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

  When the resin (A2) contains the structural unit (a2-1), its content is usually from 1 to 45 mol%, preferably from 1 to 40 mol%, based on all structural units of the resin (A2). Yes, more preferably 1 to 35 mol%, even more preferably 2 to 20 mol%.

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

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

[In the formula (a3-1),
L ^a4 represents -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond to the carbonyl group.
^Ra18 represents a hydrogen atom or a methyl group.
^Ra21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, a plurality of R ^a21 are the same or different from each other.
In the formula (a3-2),
L ^a5 represents -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond to the carbonyl group.
^Ra19 represents a hydrogen atom or a methyl group.
^Ra22 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, a plurality of ^Ra22s are the same or different from each other.
In the formula (a3-3),
L ^a6 represents -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond to the carbonyl group.
^Ra20 represents a hydrogen atom or a methyl group.
^Ra23 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, a plurality of R ^a23 are the same or different from each other.
In the formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^a7 represents a single ^{bond, * -O-, * -O -L a8} -O-, * -O -L a8 -CO-O-, * -O -L a8 -CO-O-L a9 -CO- Represents O- or ^* -O- ^La8- O-CO- ^La9- O-.
* Represents a bond to the carbonyl group.
^La8 and ^La9 independently represent an alkanediyl group having 1 to 6 carbon atoms. ]

Examples of the aliphatic hydrocarbon group for R ^a21 , R ^a22 and R ^a23 include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. No.
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group for ^Ra24 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. , Preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom of R ^a24 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluoropentyl group. Examples include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

The alkanediyl groups for ^La8 and ^La9 include methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, 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 include a 4-diyl group and a 2-methylbutane-1,4-diyl group.

In the formulas (a3-1) to (a3-3), L ^{a4 to} L ^a6 each independently preferably represent -O- or * -O- (CH _{2) in} which k3 is an integer of 1 to 4. ) _k3 -CO-O-, a group represented by the more preferably -O- _{and, * - O-CH 2 -CO} -O-, more preferably an oxygen atom.
^{Ra18 to Ra21} are preferably a methyl group.
^Ra22 and ^Ra23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, and more preferably 0 or 1.

In the equation (a3-4),
^Ra24 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 a single bond, ^* -O- or ^* -O -L ^a8 -CO-O-, more preferably an a single _{^{bond, * -O-, * -O -CH 2}} -CO- O- or ^* -O -C ₂ H ₄ is -CO-O-.

  Examples of the monomer for deriving the structural unit (a3) include a monomer described in JP-A-2010-204646, a monomer described in JP-A-2000-122294, and a monomer described in JP-A-2012-41274. No. As the structural unit (a3), formulas (a3-1-1) to (a3-1-4), formulas (a3-2-1) to (a3-2-4), and formulas (a3-3-3) Structural units represented by any one of 1) to (a3-3-4) and (a3-4-1) to (a3-4-12) are preferable, and a structural unit represented by the formula (a3-1-1): The structural unit represented by any one of the formula (a3-1-2) and the formulas (a3-2-3) to (a3-2-4) is more preferable, and the formula (a3-1-1) or the formula (a3-1-1) The structural unit represented by a3-2-3) is more preferable.

In the structural units represented by the following formulas (a3-4-1) to (a3-4-12), the compound in which the methyl group corresponding to R ^a24 is replaced by a hydrogen atom also includes the structural unit (a3-4) ) Can be cited as specific examples.

When the resin (A2) contains the structural unit (a3), the total content is usually from 5 to 70 mol%, preferably from 10 to 65 mol%, based on all the structural units of the resin (A2). , More preferably 10 to 60 mol%.
Further, the content rates of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) and the structural unit (a3-4) are each based on all the structural units of the resin (A2). Therefore, 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)>
The resin (A2) may include another structural unit (t) as a structural unit other than the structural unit (a1) and the structural unit (s). Examples of the structural unit (t) include the structural unit (a4) and the structural unit (a5) described above in addition to the structural unit (a2) and the structural unit (a3). The resin (A2) may have a structural unit other than the structural units described above, and examples of such a structural unit include structural units known in the art.

  When the resin (A2) has the structural unit (a4), the content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and more preferably 3 to 15 mol% based on all the structural units of the resin (A2). -10 mol% is more preferred.

  When the resin (A2) has the structural unit (a5), its content is preferably from 1 to 30 mol%, more preferably from 2 to 20 mol%, based on all the structural units of the resin (A2). ~ 15 mol% is more preferred.

The resin (A2) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s).
The structural unit (a1) is preferably a structural unit (a1-0), a structural unit (a1-1), a structural unit (a1-2) (preferably a structural unit having a cyclohexyl group or a cyclopentyl group) and a structural unit. At least two types of (a1-5), more preferably two types of a structural unit (a1-1) and a structural unit (a1-2) (preferably, a 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 at least one of structural units represented by a γ-butyrolactone ring, a bridged ring containing a γ-butyrolactone ring structure, or an adamantane lactone ring.

  The resin (A2) may contain a structural unit derived from a monomer having an adamantyl group (particularly, the structural unit (a1-1)) in an amount of 15 mol% or more based on the content of the structural unit (a1). preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

Each of the structural units constituting the resin (A2) can be produced by a known polymerization method (for example, a radical polymerization method) using a monomer for deriving two or more types of structural units. The content of each structural unit of the resin (A2) can be adjusted by the amount of the monomer used for polymerization.
The weight average molecular weight of the resin (A2) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, further more preferably). Is 15,000 or less). The weight average molecular weight is a value determined by gel permeation chromatography.

  The content ratio (mass ratio) of the resin (A1) and the resin (A2) in the resin (A) is, for example, 0.01: 10 to 5:10, preferably 0.05: 10 to 3:10, and more preferably The ratio is 0.1: 10 to 2:10, more preferably 0.2: 10 to 1:10.

<Resin (X)>
The resist composition of the present invention may contain a resin other than the resins (A1) and (A2) (hereinafter sometimes referred to as “resin (X)”). The resin (X) is, for example, at least one selected from a structural unit derived from the above-described acid labile monomer (a1), a structural unit derived from an acid stable monomer, and a structural unit derived from a known monomer used in the art. A resin having one type may be contained.
Examples of the structural unit that the resin (X) may further have 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 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less).
When the resist composition of the present invention contains the resin (X), the content thereof is usually 0.1 to 50% by mass based on the total amount of the resin (A) contained in the resist composition of the present invention. And preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass.

  In the resist composition of the present invention, the content of the resin (A) and the resin (X) is preferably 80% by mass or more and 99.9% by mass or less based on the solid content of the resist composition. In the present specification, the “solid content of the composition” means the total of the components of the resist composition excluding the solvent (E) described later from the resist composition of the present invention. The solid content and the content of the resin (A) with respect to the solid content can be measured by known analytical means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator is classified into a nonionic type and an ionic type, and any of the acid generators (B) in the resist composition of the present invention may be used. Nonionic acid generators include organic halides, sulfonate esters (eg, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (For example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (eg, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include a sulfonic acid anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, and JP-A-63-163452. JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3,914,407, European Patent No. 126,712. And the like, compounds which generate an acid by radiation described in, for example, can be used. Further, a compound produced by a known method may be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; is, -O - - -CH ₂ contained in the hydrogen radical, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]

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

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and It may be a group formed by combining two or more of the groups.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group Linear groups such as tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group Alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, a cyclooctane-1,5-diyl group; Divalent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group and the like And the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include any of formulas (b1-1) to (b1-3). And the group represented by In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond to Y.

In the formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group; The methylene group contained in the hydrocarbon group may be replaced by 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 the formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group; The methylene group contained in the hydrocarbon group may be replaced by 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 the formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group; The methylene group contained in the hydrocarbon group may be replaced by 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 by an oxygen atom or a carbonyl group, the number of carbon atoms before the replacement is determined by the number of the saturated hydrocarbon group. Of carbon.
Examples of the divalent saturated hydrocarbon group include the same as the divalent saturated hydrocarbon group for L ^b1 .

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

  Among them, a group represented by the formula (b1-1) or the formula (b1-3) is preferable.

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

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

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

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

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

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

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

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

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

Among the groups represented by the formula (b1-1), 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), examples of the group represented by the formula (b1-11) include the following.

Examples of the monovalent alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the monovalent alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO— include formulas (Y12) to (Y27). And the group represented by

  Among them, a group represented by any of formulas (Y1) to (Y20) is preferable, and a group represented by formula (Y11), formula (Y15), formula (Y16) or formula (Y20) is more preferable. And more preferably a group represented by the formula (Y11) or (Y15).

Examples of the substituent for the methyl group represented by Y include a halogen atom, a hydroxy group, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. A glycidyloxy group or — (CH ₂ ) _ja —O—CO—R ^b1 group (where R ^b1 is an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon having 3 to 16 carbon atoms) Represents a group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4).
Examples of the substituent of the monovalent alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms. To 16 monovalent alicyclic hydrocarbon groups, C1 to C12 alkoxy groups, C6 to C18 monovalent aromatic hydrocarbon groups, C7 to C21 aralkyl groups, C2 to C2 4 acyl group, glycidyloxy group or — (CH ₂ ) _ja —O—CO—R ^b1 group (where R ^b1 is an alkyl group having 1 to 16 carbon atoms, a monovalent oil having 3 to 16 carbon atoms) And represents a cyclic hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4).

Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include 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 monovalent aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group and a p-adamantylphenyl group; a tolyl group, a xylyl group, a cumenyl group and a mesityl group. And aryl groups such as a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

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

When Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y -CH group ₂ - is preferably replaced by -O- or -CO-.

  Y is preferably a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent. The methylene group constituting the group may be replaced by an oxygen atom, a sulfonyl group or a carbonyl group. Y is more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

As the sulfonic acid anion in the salt represented by the formula (B1), an anion represented by the formula (B1-A-1) to the formula (B1-A-33) [hereinafter referred to as “anion (B1 -A-1) ". Are preferred, and the formulas (B1-A-1) to (B1-A-4), the formula (B1-A-9), the formula (B1-A-10), and the formulas (B1-A-24) to Anions represented by any of (B1-A-33) are more preferred. In the formulas (B1-A-5), (B1-A-7), (B1-A-24), (B1-A-30) to (B1-A-33), R ⁱ² To R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. In the formulas (B1-A-32) and (B1-A-33), R ⁱ⁸ represents, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, A monovalent alicyclic hydrocarbon group of 5 to 12 or a group formed by combining them, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ⁷ is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q ¹ and Q ² represent the same meaning as described above.
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include anions described in JP-A-2010-204646.

Above all, preferred examples of the sulfonate anion in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-15).

  Among them, the sulfonic acid anion in the salt represented by the formula (B1) is represented by any one of the formulas (B1a-1) to (B1a-3) and the formulas (B1a-7) to (B1a-15). Is preferred.

The organic cation of Z ⁺ includes an organic onium cation, for example, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation, and the like, preferably, an organic sulfonium cation or an organic iodonium cation. And more preferably an arylsulfonium cation.
Z ⁺ in the formula (B1) is preferably a cation represented by any of the formulas (b2-1) to (b2-4) [hereinafter, “cation (b2-1)” according to the formula number, and the like. There is a case. ].

In the formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represent a monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent having 6 to 36 carbon atoms. A hydrogen atom contained in the monovalent aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or a monovalent alicyclic carbon atom having 3 to 12 carbon atoms. It may be substituted by a hydrogen group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the monovalent alicyclic hydrocarbon group is a halogen atom, a carbon atom having 1 to 18 carbon atoms. May be substituted with a monovalent aliphatic hydrocarbon group, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and a hydrogen atom contained in the monovalent aromatic hydrocarbon group may be a halogen atom, It may be substituted with a group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced by —O—, —SO—, or —CO—. .

R ^b7 and R ^b8 each independently represent a hydroxy group, a monovalent 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, a plurality of R ^b7 may be the same or different, and when n2 is 2 or more, a plurality of R ^b8 may be the same or different.

R ^b9 and R ^b10 each independently represent a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may form a ring together with the sulfur atom to which they are attached, and —CH ₂ — contained in the ring may be replaced by —O—, —SO—, or —CO—. .
R ^b11 represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. Represents a hydrogen group.
R ^b12 represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. And a hydrogen atom contained in the monovalent aliphatic hydrocarbon group may be substituted with a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. The contained hydrogen atom may be substituted by an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may be taken together to form a ring containing -CH-CO- to which they are bonded, and -CH _2- contained in the ring is -O-, -SO- Or it may be replaced by -CO-.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13 are the same or different. When p2 is 2 or more, a plurality of R ^b14 are the same or different. When q2 is 2 or more, a plurality of R ^b15 are the same or different. , When r2 is 2 or more, a plurality of R ^b16 are the same or different; when s2 is 2 or more, a plurality of R ^b17 are the same or different; when t2 is 2 or more, a plurality of R ^b18 are the same or different. different.

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

  Examples of the monovalent alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group Group, isobornyl group and the like. In a monovalent alicyclic hydrocarbon group in which a hydrogen atom is substituted by a monovalent aliphatic hydrocarbon group, the total number of carbon atoms of the monovalent alicyclic hydrocarbon group and the monovalent aliphatic hydrocarbon group Is preferably 20 or less.

Examples of the monovalent aromatic hydrocarbon group include phenyl, tolyl, xylyl, cumenyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, p-cyclohexylphenyl, p- And aryl groups such as an adamantylphenyl group, a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
When the monovalent aromatic hydrocarbon group contains a monovalent aliphatic hydrocarbon group or a monovalent alicyclic hydrocarbon group, the monovalent aliphatic hydrocarbon group has 1 to 18 carbon atoms. Alternatively, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms is preferable.
Examples of the monovalent aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the monovalent aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl group. .

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 a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The ring which R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded is a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. There may be. The ring includes a ring having 3 to 18 carbon atoms, and is 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, and examples thereof include the following rings.

The ring formed by R ^b9 and R ^b10 together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Good. The ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thiane-1-ium ring, a 1,4-oxathian-4-ium ring and the like can be mentioned.
The ring formed by R ^b11 and R ^b12 together may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated ring. The ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring. For example, an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, an oxoadamantane ring and the like can be mentioned.

Among the cations (b2-1) to cations (b2-4), cations (b2-1) are preferable, and cations represented by the formula (b2-1-1) (hereinafter, "cations (b2-1-1)) are more preferable. b2-1-1) ”), and more preferably a triphenylsulfonium cation (in the formula (b2-1-1), v2 = w2 = x2 = 0), a diphenyltolylsulfonium cation (formula (b2-1-1)). In (b2-1-1), v2 = w2 = 0 and x2 = 1, and R ^b21 is a methyl group.) Or a tolyl sulfonium cation (v2 = w2 = in the formula (b2-1-1)) x2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl groups).

In the formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom, a hydroxy group, a C 1-18 monovalent aliphatic hydrocarbon group, a C 1-12 alkoxy group or a C 3-18 Represents a monovalent alicyclic hydrocarbon group. It is also possible that two selected from R ^b19 to R ^b21 together form a ring containing a sulfur atom.
v2, w2 and x2 each independently represent an integer of 0 to 5.
When v2 is 2 or more, a plurality of R ^b19 are the same or different; when w2 is 2 or more, a plurality of R ^b20 are the same or different; when x2 is 2 or more, a plurality of R ^b21 are the same or different .

The ring or two of R ^b19 to R ^b21 is that together form a monocyclic, polycyclic, aromatic, may be any ring nonaromatic, sulfur atom 1 If it contains the above, it may further contain one or more oxygen atoms.
The monovalent aliphatic hydrocarbon group of R ^{b19 to} R ^b21 preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.

Among them, R ^b19 , R ^b20 and R ^b21 each independently preferably represent a halogen atom (more preferably a fluorine atom), a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a carbon number. or represents from 1 to 12 alkoxy groups, it is preferable two selected from R ^b19 to R ^b21 is that together form a ring containing an oxygen atom and a sulfur atom.
v2, w2 and x2 are each independently preferably 0 or 1.

Specific examples of the cation (b2-1-1) include the cations described in JP-A-2010-204646, and examples of the cation (b2-1) include the following cations.

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

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

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

  The acid generator (B1) is a combination of the above-mentioned sulfonic acid anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B1), preferably, an anion represented by any of formulas (B1a-1) to (B1a-3) and formulas (B1a-7) to (B1a-15) and a formula (B1a-15) b2-1-1) or a combination with a cation represented by the formula (b2-3).

  Preferred examples of the acid generator (B1) include those represented by the formulas (B1-1) to (B1-30). Among them, the formula (B1-1) containing an arylsulfonium cation and the formula (B1-1) B1-2), Formula (B1-3), Formula (B1-5), Formula (B1-6), Formula (B1-7), Formula (B1-11), Formula (B1-12), Formula (B1) -13), Formula (B1-14), Formula (B1-17), Formula (B1-20), Formula (B1-21), Formula (B1-23), Formula (B1-24), Formula (B1- 25), those represented by the formula (B1-26) or the formula (B1-29) are particularly preferable.

The content of the acid generator (B1) is preferably from 30% by weight to 100% by weight, more preferably from 50% by weight to 100% by weight, based on the total amount of the acid generator (B). More preferably, it is only the generator (B1).
The content of the acid generator (B) is preferably at least 1 part by mass (more preferably at least 3 parts by mass), preferably at most 30 parts by mass (more preferably at least 25 parts by mass) based on 100 parts by mass of the resin (A1). Part below). The resist composition of the present invention may contain one kind of acid generator (B) alone, or may contain plural kinds.

<Solvent (E)>
The content of the solvent (E) is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, 99.9% by mass or less, and preferably 99% by mass or less in the resist composition. It 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, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; The solvent (E) may contain one kind alone or two or more kinds.

<Quencher (C)>
The resist composition of the present invention may contain a quencher (C). The content of the quencher (C) is preferably about 0.01 to 5% by mass based on the solid content of the resist composition.

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

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

  Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, and 3- (trifluoromethyl) phenyltrimethyl. Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like.

<Low acidity salt>
The acidity of a salt that generates an acid having a lower acidity than the acid generated from the acid generator is indicated by an acid dissociation constant (pKa). The salt that generates an acid having a lower acidity than the acid generated from the acid generator is a salt in which the pKa of the acid generated from the salt is usually -3 <pKa, and preferably −1 <pKa <7. And more preferably a salt of 0 <pKa <5. Examples of the salt weaker than the acid generated from the acid generator include a salt represented by the following formula, a weak acid inner salt represented by the formula (D), and JP-A-2012-229206 and JP-A-2012-6908. JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745.

<Weak acid inner salt (D)>
The weak acid inner salt (D) is a compound represented by the formula (D).
[In the formula (D),
R ^D1 and R ^D2 are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, and an acyloxy group having 2 to 7 carbon atoms. , An alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m ′ and n ′ each independently represent an integer of 0 to 4; when m ′ is 2 or more, a plurality of R ^D1 are the same or different; when n ′ is 2 or more, a plurality of R ^D2 are Identical or different. ]

The hydrocarbon group of R ^D1 and R ^D2 in the compound represented by the formula (D) includes a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group and Examples include groups formed by combining these.
Examples of the monovalent aliphatic hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, and a nonyl group.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be saturated or unsaturated. Examples thereof include a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclononyl group, a cyclododecyl group, a norbornyl group, and an adamantyl group.
Examples of the monovalent aromatic hydrocarbon group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-ethylphenyl group. Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group And aryl groups such as a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the group formed by combining these include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, and an aralkyl group (for example, a phenylmethyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 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) 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, and a cyclohexanecarbonyl group.
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), R ^D1 and R ^D2 each independently represent an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, An acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group or a halogen atom is preferable.
m ′ and n ′ are each independently preferably an integer of 0 to 2, and more preferably 0. When m 'is 2 or more, a plurality of R ^D1 are the same or different, and when n' is 2 or more, a plurality of R ^D2 are the same or different.

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

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

  The content of the salt having a weak acidity, in particular, the weak acid inner salt (D) is preferably 0.01 to 5% by mass, more preferably 0.01 to 4% by mass, based on the solid content of the resist composition. And particularly preferably 0.01 to 3% by mass.

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

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A) and an acid generator (B), and optionally, a quencher (C), a resin (X), and an acidity of a weak acid inner salt (D). Can be prepared by mixing a weak salt, a solvent (E) and another component (F). The mixing order is arbitrary and is not particularly limited. An appropriate temperature can be selected from 10 to 40 ° C. depending on the type of the resin and the like and the solubility of the resin and the like in the solvent (E). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to perform filtration using a filter having a pore size of about 0.003 to 0.2 μm.

<Resist pattern manufacturing method>
The method for producing a resist pattern according to the present invention includes:
(1) a step of applying the resist composition of the present invention on a substrate,
(2) drying the composition after application to form a composition layer;
(3) exposing the composition layer to light,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

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

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

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. The exposure light source, which emits laser light in a UV-region such as a KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser source (YAG or semiconductor laser Etc.), which emits harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by converting the wavelength of the laser light from the above, and irradiates an electron beam or ultra-ultraviolet light (EUV). it can. In the present specification, irradiating these radiations may be collectively referred to as “exposure”. At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

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

  The heated composition layer 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, a dynamic dispense method, and the like. The development temperature is, for example, preferably 5 to 60 ° C., and the development time is, for example, preferably 5 to 300 seconds. By selecting the type of the developer as follows, a positive resist pattern or a negative resist pattern can be produced.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as a developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) may, for example, be mentioned.
The alkali developer may contain a surfactant.
After the development, it is preferable to wash the resist pattern with ultrapure water, and then remove water remaining on the substrate and the pattern.

When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as “organic developer”) is used as a developer.
Examples of the organic solvent contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. Ether solvents; amide solvents such as N, N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and further preferably substantially only the organic solvent.
Among them, 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 from 50% by mass to 100% by mass, more preferably from 90% by mass to 100% by mass, and substantially butyl acetate and / or 2% by mass. More preferably it is only heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a type different from 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 is preferably an alcohol solvent or an ester solvent.
After the cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

<Applications>
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.

The present invention will be described more specifically with reference to examples. In the examples, "%" and "part" representing the content or the use amount are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Equipment: HLC-8120GPC type (Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (Tosoh Corporation)
Eluent: tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

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

Synthesis Example 1 [Synthesis of Compound Represented by Formula (a4-5-3)]
1.00 part of the compound represented by the formula (a4-5-3-1), 5 parts of dimethylformamide and 0.80 part of potassium carbonate were stirred and mixed at 23 ° C for 30 minutes. To the obtained mixture, 2.51 parts of a compound represented by the formula (a4-5-3-2) was added, and the mixture was stirred at 50 ° C for 5 hours. To the obtained reaction product, 0.08 part of potassium carbonate and 0.10 part of a compound represented by the formula (a4-5-3-1) were added, and the mixture was stirred at 50 ° C for 1 hour. To the obtained reaction product, 50 parts of tert-butyl methyl ether and 25 parts of ion-exchanged water were charged and stirred at 23 ° C. for 30 minutes. This was allowed to stand, and liquid separation was performed to wash the organic layer with water. 25 parts of ion-exchanged water was charged to the collected organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to separate the organic layer. Such a washing operation was repeated five times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation conditions: stationary phase: silica gel 60-200 mesh, Merck Co., Ltd., developing solvent: n-heptane / ethyl acetate). 1.68 parts of compounds represented by (a4-5-3) were obtained.
MS (mass spectrometry): 266.0 (molecular ion peak)

Synthesis Example 2 [Synthesis of Compound Represented by Formula (a4-6-3)]
3.07 parts of the compound represented by the formula (a4-6-3-1), 10 parts of dimethylformamide and 0.80 part of potassium carbonate were stirred and mixed at 23 ° C for 30 minutes. To the obtained mixture, 2.51 parts of a compound represented by the formula (a4-6-3-2) was added, and the mixture was stirred at 50 ° C for 5 hours. The obtained reaction product was charged with 50 parts of ethyl acetate and 25 parts of ion-exchanged water, and stirred at 23 ° C. for 30 minutes. This was allowed to stand, and liquid separation was performed to wash the organic layer with water. 25 parts of ion-exchanged water was charged to the collected organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to separate the organic layer. Such a washing operation was repeated five times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation conditions: stationary phase: silica gel 60-200 mesh manufactured by Merck, developing solvent: n-heptane / ethyl acetate = 1/5). As a result, 3.68 parts of a compound represented by the formula (a4-6-3) was obtained.
MS (mass spectrometry): 444.1 (molecular ion peak)

Synthesis Example 3 [Synthesis of Compound Represented by Formula (a4-6-7)]
2.74 parts of the compound represented by the formula (a4-6-7-1), 10 parts of dimethylformamide, 0.20 part of potassium iodide and 0.80 part of potassium carbonate were stirred and mixed at 23 ° C. for 30 minutes. To the obtained mixture, 2.51 parts of a compound represented by the formula (a4-6-7-2) was added, and the mixture was stirred at 50 ° C for 12 hours. The obtained reaction product was charged with 50 parts of ethyl acetate and 25 parts of ion-exchanged water, and stirred at 23 ° C. for 30 minutes. After allowing this to stand, the organic layer was washed with water by liquid separation. 25 parts of ion-exchanged water was charged to the collected organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to separate the organic layer. Such a washing operation was repeated five times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation conditions: stationary phase: silica gel 60-200 mesh manufactured by Merck, developing solvent: n-heptane / ethyl acetate = 1/5). As a result, 1.22 parts of a compound represented by the formula (a4-6-7) was obtained.
MS (mass spectrometry): 416.1 (molecular ion peak)

Synthesis Example 4 [Synthesis of Compound Represented by Formula (a4-5-5)]
1.00 part of the compound represented by the formula (a4-5-5-1), 5 parts of dimethylformamide and 0.80 parts of potassium carbonate were stirred and mixed at 23 ° C for 30 minutes. 2.30 parts of a compound represented by the formula (a4-5-5-2) was added to the obtained mixture, and the mixture was stirred at 50 ° C for 5 hours. To the obtained reaction product, 50 parts of tert-butyl methyl ether and 25 parts of ion-exchanged water were charged and stirred at 23 ° C. for 30 minutes. This was allowed to stand, and liquid separation was performed to wash the organic layer with water. 25 parts of ion-exchanged water was charged to the collected organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to separate the organic layer. Such a washing operation was repeated five times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation conditions: stationary phase: silica gel 60-200 mesh, Merck Co., Ltd., developing solvent: n-heptane / ethyl acetate). 1.26 parts of compounds represented by (a4-5-5) were obtained.
MS (mass spectrometry): 248.1 (molecular ion peak)

Synthesis Example 5 [Synthesis of compound represented by formula (a4-6-13)]
3.07 parts of the compound represented by the formula (a4-6-13-1), 10 parts of dimethylformamide and 0.80 part of potassium carbonate were stirred and mixed at 23 ° C. for 30 minutes. 2.30 parts of the compound represented by the formula (a4-6-13-2) was added to the obtained mixture, and the mixture was stirred at 50 ° C for 5 hours. The obtained reaction product was charged with 50 parts of ethyl acetate and 25 parts of ion-exchanged water, and stirred at 23 ° C. for 30 minutes. This was allowed to stand, and liquid separation was performed to wash the organic layer with water. 25 parts of ion-exchanged water was charged to the collected organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to separate the organic layer. Such a washing operation was repeated five times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation conditions: stationary phase: silica gel 60-200 mesh manufactured by Merck, developing solvent: n-heptane / ethyl acetate = 1/5). As a result, 2.96 parts of a compound represented by the formula (a4-6-13) was obtained.
MS (mass spectrometry): 426.2 (molecular ion peak)

Synthesis Example 6: Synthesis of salt represented by formula (B1-5)
50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, and the mixture is stirred at 23 ° C. for 30 minutes to give a compound represented by the formula (B1-5-b) 16.27 parts was added dropwise, and the mixture was stirred at 23 ° C. for 1 hour to obtain a solution containing a 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 to the obtained solution containing the salt represented by the formula (B1-5-c), Stirred at 23 ° C. for 12 hours. Since the obtained reaction solution had been separated into two layers, the chloroform layer was separated and taken out. Further, 84.15 parts of ion-exchanged water was added to the chloroform layer, and the mixture was washed with water. This operation was repeated five times. 3.88 parts of activated carbon was added to the obtained chloroform layer, stirred, and filtered. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the obtained residue, followed by stirring and concentration. 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. 200 parts of n-heptane was added to the obtained residue, 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 7 [Synthesis of salt represented by formula (B1-21)]

30.00 parts of a compound represented by the formula (B1-21-b) obtained by the method described in JP-A-2008-209917, and a salt represented by the formula (B1-21-a) 35.50 , 100 parts of chloroform and 50 parts of ion-exchanged water, and the mixture was 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. Further, 30 parts of ion-exchanged water was added to the chloroform layer, followed by washing with water. This operation was repeated five times. The chloroform layer is concentrated, 100 parts of tert-butyl methyl ether is added to the obtained residue, and the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt 48 represented by the formula (B1-2-1-c). .57 parts were obtained.

20.00 parts of the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d), and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. .
To the obtained mixture, 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, separated, and an organic layer was taken out. 50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. This washing operation was repeated five times. The obtained organic layer was concentrated. The obtained residue was dissolved in 53.51 parts of acetonitrile, concentrated, and 113.05 parts of tert-butyl methyl ether was added and stirred. Thereafter, the mixture was filtered to obtain 10.47 parts of a salt represented by the formula (B1-21).

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

Synthesis Example 8 [Synthesis of salt represented by formula (B1-22)]
11.26 parts of the salt represented by the formula (B1-22-a), 10.00 parts of the compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged, and the mixture was heated at 23 ° For 15 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out. Further, 15 parts of ion-exchanged water was added to the chloroform layer, followed by washing with water. This operation was repeated five times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes, and filtered to obtain a salt represented by the formula (B1-22-c). 75 parts were obtained.

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 are charged, and the mixture is heated at 23 ° C. for 30 minutes. Stirred. 0.12 parts of copper (II) dibenzoate was added to the obtained mixture, 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, separated, and the organic layer was taken out. 12.50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. This washing operation was repeated eight times. The obtained organic layer was concentrated. To the obtained residue, tert-butyl methyl ether (50 parts) 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 The compounds (monomers) used in the synthesis of the resin are shown below.

Hereinafter, these monomers are referred to as “monomer (a1-1-z1)” or the like according to the formula number.

Synthesis Example 9 [Synthesis of Resin A1-1]
The monomers (a4-5-3) and (a5-1-1) were used as monomers, and the molar ratio (monomer (a4-5-3): monomer (a5-1-1)) was 50:50. And the mixture was added, and a solution was prepared by adding 1.2% by mass of methyl isobutyl ketone to the total amount of monomers. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin. The resin is filtered, and a resin A1-1 (copolymer) having a weight average molecular weight of 1.1 × 10 ⁴ is obtained in a yield. Obtained at 80%. This resin A1-1 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1-2]
The monomers (a4-6-3) and (a5-1-1) were used as monomers, and the molar ratio (monomer (a4-6-3): monomer (a5-1-1)) was 50:50. And the mixture was added, and a solution was prepared by adding 1.2% by mass of methyl isobutyl ketone to the total amount of monomers. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin is filtered. Thus, a resin A1-2 (copolymer) having a weight-average molecular weight of 1.2 × 10 ⁴ is obtained. Obtained at 77%. This resin A1-2 has the following structural units.

Synthesis Example 11 [Synthesis of Resin A1-3]
The monomers (a4-6-7) and (a5-1-1) were used as monomers, and the molar ratio (monomer (a4-6-7): monomer (a5-1-1)) was 50:50. And the mixture was added, and a solution was prepared by adding 1.2% by mass of methyl isobutyl ketone to the total amount of monomers. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin. The resin is filtered, and a resin A1-3 (copolymer) having a weight average molecular weight of 1.3 × 10 ⁴ is obtained. Obtained at 70%. This resin A1-3 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-4]
A monomer (a4-5-3) was used as a monomer, and methylisobutyl ketone 1.2 times by mass of the total monomer amount was added to form a solution. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and this resin was filtered to obtain a resin A1-4 having a weight average molecular weight of 1.2 × 10 ^{4 in} a yield of 83%. . This resin A1-4 has the following structural units.

Synthesis Example 13 [Synthesis of Resin A1-5]
A monomer (a4-6-3) was used as a monomer, and methylisobutyl ketone 1.2 times by mass of the total monomer amount was added to form a solution. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered, whereby a resin A1-5 having a weight average molecular weight of 1.3 × 10 ⁴ was obtained in a yield of 83%. . This resin A1-5 has the following structural units.

Synthesis Example 14 [Synthesis of Resin A1-6]
The monomers (a4-5-5) and (a5-1-1) were used as the monomers, and the molar ratio (monomer (a4-5-5): monomer (a5-1-1)) was 50:50. And the mixture was added, and a solution was prepared by adding 1.2% by mass of methyl isobutyl ketone to the total amount of monomers. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin is filtered. Thus, a resin A1-6 (copolymer) having a weight average molecular weight of 1.2 × 10 ⁴ is obtained. Obtained at 74%. This resin A1-6 has the following structural units.

Synthesis Example 15 [Synthesis of Resin A1-7]
The monomers (a4-6-13) and (a5-1-1) were used as the monomers, and the molar ratio (monomer (a4-6-13): monomer (a5-1-1)) was 50:50. And the mixture was added, and a solution was prepared by adding 1.2% by mass of methyl isobutyl ketone to the total amount of monomers. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin is filtered. Thus, a resin A1-7 (copolymer) having a weight average molecular weight of 1.1 × 10 ⁴ is obtained. Obtained at 71%. This resin A1-7 has the following structural units.

Synthesis Example 16 [Synthesis of Resin A1-8]
A monomer (a4-5-5) was used as a monomer, and methylisobutylketone of 1.2 times the total amount of the monomers was added to form a solution. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and this resin was filtered to obtain a resin A1-8 having a weight average molecular weight of 1.3 × 10 ^{4 in} a yield of 77%. . This resin A1-8 has the following structural units.

Synthesis Example 17 [Synthesis of Resin A1-9]
A monomer (a4-6-13) was used as a monomer, and methylisobutyl ketone 1.2 times the mass of the total monomer was added to form a solution. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered to obtain a resin A1-9 having a weight average molecular weight of 1.2 × 10 ^{4 in} a yield of 74%. . This resin A1-9 has the following structural units.

Synthesis Example 18 [Synthesis of Resin A1X-1]
A monomer (a4-5-x) was used as a monomer, and methylisobutyl ketone 1.2 times by mass of the total monomer amount was added to form a solution. To this solution, azobis (2,4-dimethylvaleronitrile) was added as an initiator in an amount of 4 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and this resin was filtered to obtain a resin A1X-1 having a weight average molecular weight of 8.9 × 10 ^{3 in} a yield of 79%. . This resin A1X-1 has the following structural units.

Synthesis Example 19 [Synthesis of resin A1X-2]
The monomers (a4-0-12) and (ax) were used as the monomers, and they were mixed so that the molar ratio (monomer (a4-0-12): monomer (ax)) became 20:80. 1.2 mass times the amount of methyl isobutyl ketone was added to obtain a solution. To this solution, azobis (2,4-dimethylvaleronitrile) was added as an initiator in an amount of 5 mol% based on the total amount of monomers, and the mixture was heated at 75 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin. The resin is filtered, and a resin A1X (copolymer) having a weight average molecular weight of 4.5 × 10 ³ is obtained in a yield of 68%. I got it. This resin A1X has the following structural units.

Synthesis Example 20 [Synthesis of Resin A2-1]
As monomers, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3) and monomer (a3-4-2) were used, and their molar ratios were [monomer (a1-1 -3): Monomer (a1-2-9): Monomer (a2-1-3): Monomer (a3-4-2)] is mixed at 45: 14: 2.5: 38.5, A solution was prepared by adding propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of monomers. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added to this solution as initiators based on the total amount of monomers, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin is again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution is poured into a mixed solvent of methanol and water to precipitate the resin, and the resin is filtered twice to perform a reprecipitation operation twice. Resin A2-1 (copolymer) having a molecular weight of 7.6 × 10 ³ was obtained with a yield of 68%. This resin A2-1 has the following structural units.

Synthesis Example 21 [Synthesis of Resin A2-2]
Monomers (a1-1-3), monomers (a1-2-9), monomers (a2-1-1) and monomers (a3-4-2) were used as monomers, and their molar ratios were [monomer (a1-1 -3): Monomer (a1-2-9): Monomer (a2-1-1): Monomer (a3-4-2)] is mixed at 45: 14: 2.5: 38.5, A solution was prepared by adding propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of monomers. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added to this solution as initiators based on the total amount of monomers, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin is again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution is poured into a mixed solvent of methanol and water to precipitate the resin, and the resin is filtered twice to perform a reprecipitation operation twice. Resin A2-2 (copolymer) having a molecular weight of 7.9 × 10 ³ was obtained with a yield of 70%. This resin A2-2 has the following structural units.

Synthesis Example 22 [Synthesis of Resin A2X-1]
As the monomers, a monomer (a1-1-1), a monomer (a3-1-1) and a monomer (a2-1-1) were used, and their molar ratio [monomer (a1-1-1): monomer (a3-1) was used. -1): Monomer (a2-1-1)] was mixed to give a ratio of 35:45:20, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of monomers was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total amount of the monomers. Heat for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin is filtered, whereby a resin A2X-1 (copolymer) having a weight average molecular weight of 7.0 × 10 ³ is obtained. Obtained at 88%. This resin A2X-1 has the following structural units.

Synthesis Example 23 [Synthesis of Resin A2X-2]
A monomer (a3-2-1x), a monomer (a2-1-3) and a monomer (a4-6-x) were used as monomers, and the molar ratio thereof was [monomer (a3-2-1x): monomer (a2-1)]. -3): Monomer (a4-6-x)] was mixed to give a ratio of 50:10:40, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of the monomers was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total amount of monomers, and these were added at 70 ° C. Heat for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed solvent of methanol / water to precipitate a resin. The resin is filtered, and a resin A2X (copolymer) having a weight average molecular weight of 8.1 × 10 ³ is obtained in a yield of 68%. I got it. This resin A2X has the following structural units.

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

<Resin>
A1-1 to A1-9: Resin A1-1 to Resin A1-9
A2-1, A2-2, A1X-1, A1X-2: Resin A2-1, Resin A2-2, Resin A1X-1, Resin A1X-2 A2X-1, A2X-2: Resin A2X-1, Resin A2X -2
<Acid generator>
B1-5: Salt represented by formula (B1-5) B1-21: Salt represented by formula (B1-21) B1-22: Salt represented by formula (B1-22) <Weak acid inner salt (D)>
D1: (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

<Manufacture of resist pattern and its evaluation>
A composition for an organic antireflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] is applied on a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a 78 nm-thick film. An organic anti-reflection film was formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (prebaking) was 85 nm.
The obtained silicon wafer was prebaked (PB) on a direct hot plate at a temperature described in the “PB” column of Table 1 for 60 seconds. The exposure amount is stepwise applied to the wafer on which the resist composition film is formed, using an ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light]. And the line and space pattern was subjected to immersion exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed on a hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds, and further for 60 seconds with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. Paddle development was performed to obtain a resist pattern.

  In each of the obtained resist pattern films, the exposure amount at which the 50 nm line and space pattern became 1: 1 was defined as the effective sensitivity.

<Line edge roughness evaluation (LER)>
The wall surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and the width (nm) of the unevenness of the side wall of the resist pattern was determined. This swing width
If the size is 4 nm or less,
Those exceeding 4 nm were rated as x. Table 2 shows the results.

<Defect evaluation>
The resist composition was applied (spin-coated) on a 12-inch silicon wafer (substrate) so that the film thickness after drying was 0.15 μm. After the application, the composition was prebaked (PB) on a direct hot plate at a temperature shown in the PB column of Table 1 for 60 seconds to form a composition layer on the wafer.
The wafer on which the composition layer was formed was rinsed with water for 60 seconds using a developing machine [ACT-12; manufactured by Tokyo Electron Limited].
Thereafter, the number of defects on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. Table 2 shows the results.

  From the above results, it can be seen that the resist composition of the present invention has few defects and good line edge roughness.

  The resist composition of the present invention has good defects and line edge roughness, and is useful for fine processing of semiconductors.

Claims (8)

A resin (A1) having a group represented by the formula (a4-x),
A resin (A2) having two or more acid labile groups represented by the formula (1) and / or the formula (2), and
A resist composition containing an acid generator.
[In the formula (a4-X),
n represents 0 or 1.
R ⁴ represents a fluorinated alkyl group having 1 to 12 carbon atoms.
* Represents a bond. ]
[In equation (1),
Which R ^a1, R ^a2 and a R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or a group composed of a combination of these 3 to 20 carbon atoms, R ^a1 and R ^a2 Combine with each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]
[In equation (2),
R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms;
R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocyclic ring having 3 to 20 carbon atoms together with X and the carbon atom to which they are bonded. And —CH ₂ — contained in the hydrocarbon group and the divalent heterocycle may be replaced by —O— or —S—.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ] The resist composition according to claim 1, wherein the structural unit having a group represented by the formula (a4-x) is a structural unit represented by the formula (a4-5) or (a4-6).
[In the formula (a4-5),
R ⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms and a fluorine atom.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ represents a single bond or ^{* -L 2 -X 51 - (L} 3 -X 52) g - representing the. * Represents a bond to an oxygen atom.
L ² and L ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ⁵¹ and X ⁵² each independently represent —O— or ** — CO—O—. ** represents a bond to L ² or L ³ .
g represents 0 or 1. ]
[In the formula (a4-6),
R ⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms and a fluorine atom.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ represents a single bond or ^{* -A 2 -X 61 - (A} 3 -X 62) h - represents a. * Represents a bond to an oxygen atom.
A ² and A ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ⁶¹ and X ⁶² are each independently, -O -, - CO-O- or an -O-CO-.
h represents 0 or 1.
W ¹ represents a divalent alicyclic hydrocarbon group having 5 to 18 carbon atoms.
n represents 0 or 1. ] 3. The resist composition according to claim 1, wherein the resin (A1) further contains a structural unit represented by the formula (a5).
[In the formula (a5),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. You may. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁴ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁴ 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 by an oxygen atom or a carbonyl group. ] R ² is, the resist composition according to claim 3, wherein an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms. The resist composition according to any one of claims 1 to 4, wherein the resin (A2) is a resin containing a structural unit represented by the formula (a1-1) or a structural unit represented by the formula (a1-2). .
[In the formulas (a1-1) and (a1-2),
L ^a1 and L ^a2 each independently, -O- or _{^{* -O- (CH 2) k1 -CO}} -O- the stands, k1 represents an integer of 1-7, * the binding of -CO- Represent hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents an integer of 0 to 14.
n1 represents the integer of 0-10.
n1 'represents the integer of 0-3. ] The resist composition according to claim 1, wherein the acid generator is a salt represented by the formula (B1).
[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; it is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group of radicals and the monovalent, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]   The resist composition according to claim 1, further comprising a salt having a lower acidity than the acid generated from the acid generator. (1) a step of applying the resist composition according to any one of claims 1 to 7 on a substrate,
(2) drying the composition after application to form a composition layer;
(3) exposing the composition layer to light,
(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 comprising: