JP6246535B2 - Resin, resist composition and method for producing resist pattern - Google Patents

Description

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

  Patent Document 1 describes a resist composition using a resin composed of a combination of the following structural units and bis (4-t-butylphenyl) iodonium nonafluorobutanesulfonate as an acid generator.

  Patent Document 2 describes a resist composition using a resin composed of a combination of the following structural units and a salt represented by the formula (B1-2) as an acid generator.

  Further, it is known that when a resist pattern is formed from a resist composition by photolithography, a positive resist pattern is obtained when developed with an alkaline developer, and a negative resist pattern is obtained when developed with an organic solvent ( Non-patent document 1).

JP 2002-62657 A JP 2010-134445 A

Published by Techno Times Inc. Monthly Display '11 June p. 31

  A negative resist pattern formed from a conventional resist composition may not always have a satisfactory shape.

The present invention includes the following inventions.
[1] A resist composition comprising a structural unit represented by formula (I) and a resin containing a structural unit having an acid labile group.

[In the formula (I),
R ¹ 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 divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and at least one methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, and the saturated hydrocarbon group The hydrogen atom contained in may be substituted with a hydroxy group.
R ² represents an alkyl group having 1 to 6 carbon atoms.
m represents an integer of 0 to 5, and when m is 2 or more, the plurality of R ² are the same or different. ]
[2] The resist composition according to [1], wherein L ^{1 in} formula (I) is a group represented by formula (L1-1 ′).

[In the formula (L1-1 ′),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^{x1 ′} represents a divalent chain saturated hydrocarbon group having 1 to 16 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 16 carbon atoms, or a group formed by combining them.
L ^x2 represents a single bond or a divalent chain saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^{x1 ′} and L ^x2 is 16 or less.
* Represents a bond with an oxygen atom. ]
[3] The resist composition according to [2], wherein the group represented by the formula (L1-1 ′) is a group represented by the formula (L1-1).

[In the formula (L1-1),
X ^x1 and L ^x2 represent the same groups as described above.
L ^x1 represents a divalent chain saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
* Represents a bond with an oxygen atom. ]
[4] The resist composition according to [1], wherein L ^{1 in} formula (I) is a group represented by formula (L1-4).

[In the formula (L1-4),
X ^x3 represents a carbonyloxy group or an oxycarbonyl group.
L ^x8 and L ^x9 represent a single bond or a divalent chain 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.
* Represents a bond with an oxygen atom. ]
[5] (1) A step of applying the resist composition according to any one of [1] to [4] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including:

  According to the resist composition of the present invention, a negative resist pattern having a good shape can be produced.

FIG. 1 is a diagram illustrating classification of cross-sectional shapes of line and space patterns.

  In the present specification, “(meth) acrylate” means “at least one of acrylate and methacrylate”. The notations such as “(meth) acrylic acid” and “(meth) acryloyl” have the same meaning.

<Resist composition>
The resist composition of the present invention contains a resin (A) and an acid generator (B).

<Resin (A)>
The resin (A) includes a structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”) and a structural unit having an acid labile group. Since the structural unit (I) and the structural unit having an acid labile group are included, a negative resist pattern having a good shape can be produced.

<Structural unit represented by formula (I)>
The structural unit (I) is represented by the formula (I).

[In the formula (I),
R ¹ 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 divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and at least one methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, and the saturated hydrocarbon group The hydrogen atom contained in may be substituted with a hydroxy group.
R ² represents an alkyl group having 1 to 6 carbon atoms.
m represents an integer of 0 to 5, and when m is 2 or more, the plurality of R ² are the same or different. ]

Examples of the halogen atom for R ¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group for R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. Preferably, it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom for R ¹ include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms of L ¹ include groups represented by any of formulas (L1-1 ′) and (L1-2) to formula (L1-5). . In the following formula, * represents a bond with an oxygen atom.

In formula (L1-1 ′),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^{x1 ′} represents a divalent chain saturated hydrocarbon group having 1 to 16 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 16 carbon atoms, or a group formed by combining them. .
L ^x2 represents a single bond or a divalent chain saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^{x1 ′} and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent chain saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent chain saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
X ^x2 represents a carbonyloxy group or an oxycarbonyl group.
L ^x5 represents a divalent chain saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent chain saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.
In formula (L1-4),
X ^x3 represents a carbonyloxy group or an oxycarbonyl group.
L ^x8 and L ^x9 represent a single bond or a divalent chain 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.
In formula (L1-5),
X ^x4 represents a carbonyloxy group or an oxycarbonyl group.
L ^x10 represents a single bond or a divalent chain saturated hydrocarbon group having 1 to 13 carbon atoms.
W ^x2 represents a divalent alicyclic saturated hydrocarbon group having 3 to 16 carbon atoms.
However, the total carbon number of L ^x10 and W ^x2 is 16 or less.

  The group represented by the formula (L1-1 ′) is preferably a group represented by the formula (L1-1).

[In the formula (L1-1),
X ^x1 and L ^x2 represent the same meaning as X ^x1 and L ^x2 in the formula (L1-1 ').
L ^x1 represents a divalent chain saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
* Represents a bond with an oxygen atom. ]

L ^{x1 ′} is preferably a divalent chain saturated hydrocarbon group having 1 to 8 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, more preferably a methylene group or an ethylene group. Or an adamantanediyl bismethylene group.
L ^x1 is preferably a C 1-8 divalent chain saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent chain saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond.
L ^x3 is preferably a divalent chain saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent chain saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent chain 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 chain saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent chain saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent chain 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 chain saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond, a methylene group or an ethylene 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.
L ^x10 is preferably a single bond or a divalent chain saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x2 is preferably a C 3-10 divalent alicyclic saturated hydrocarbon group, more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

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

  As group represented by a formula (L1-5), the bivalent group shown below is mentioned, for example.

L ¹ is preferably a group represented by any one of formula (L1-1), formula (L1-4) or formula (L1-5), more preferably formula (L1-1) or formula a group represented by (L1-4), more _{preferably, * - CH 2 -CH 2 -O} -CO -, * - Ad-O-CH 2 -CH 2 -O-CO- or * -CH ₂ -Ad-CH ₂ -O-CO- (* represents a bond with an oxygen atom. Ad represents an adamantanediyl group).

Examples of the alkyl group for R ² 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 or an ethyl group.
m is preferably 0 to 4, more preferably 0 to 2.

The lactone ring part of the structural unit (I) is preferably represented by the following formula. In the formula, * represents a bond with L ¹ .

  Specific examples of the structural unit (I) are shown below.

The structural units of the above formulas (I-1) to (I-7) are all examples in which R ^{1 in the} above formula (I) is a methyl group. The structural unit which is the same as each of the above formulas (I-1) to (I-7) except that R ¹ is a hydrogen atom can also be given as specific examples of the structural unit (I).

  The structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).

[In the formula (I ′), R ¹ , R ² , L ¹ and m represent the same meaning as described above. ]

  Compound (I ') can be easily obtained from the market, for example, Macromol. Chem. Phys. 195, 2381-2400 (1994).

  The content of the structural unit (I) contained in the resin (A) is preferably 1 to 60 mol%, more preferably 3 to 55 mol%, still more preferably 5 with respect to the total structural units of the resin (A). It is -50 mol%, Most preferably, it is 10-40 mol%.

  The resin (A) is also a resin having a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”), and further decomposes by the action of an acid, for example, butyl acetate or 2- It preferably has the property of reducing solubility in heptanone.

<Structural unit (a)>
The “acid labile group” means a group that has a leaving group, and the leaving group is removed by contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

[In the formula (1), R ^a1 , R ^a2 and R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms or a combination thereof. R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]

[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. The hydrocarbon group and the methylene group constituting the divalent hydrocarbon group may be replaced with an oxygen atom or a sulfur atom. L ^a1 and L ^a2 each independently represent an oxygen atom or a sulfur atom. * Represents a bond. ]

^Examples of the alkyl group represented by R ^{a1 to} R ^{a3 in} Formula (1) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group represented by R ^{a1 to} R ^{a3 in} formula (1) may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

Examples of the group obtained by combining the alkyl group of R ^{a1 to} R ^{a3 in} formula (1) and the alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group. Carbon number of the group which combined the alkyl group and the alicyclic hydrocarbon group is 20 or less, Preferably it is 4-16.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^{a2 in} formula (1) are bonded to each other to form a divalent hydrocarbon group include the following groups. It is done. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms. In each formula, R ^a3 has the same meaning as described above, and * represents a bond with an oxygen atom.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, 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), 1- ( Adamantane-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group), 1-alkylcycloalkane-1-yl oxycarbonyl group (wherein (1), R ^a1, R ^a2 and the carbon atom to which they are attached form a cycloalkyl group, R ^a3 is alkyl group) and 1- (cycloalkane-1-yl 1-alkyl alkoxycarbonyl group (wherein (1), R ^a1 and R ^a2 is an alkyl group, R ^a3 is group a cycloalkyl group) and the like.

Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′ in} formula (2) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} are the same as those described above.
Examples of the aromatic hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, and a xylyl group. , Aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′ of} formula (2) with each other include a group in which one hydrogen atom has been removed from the hydrocarbon groups of R ^{a1 ′ to} R ^{a3 ′.} Is mentioned.
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 for deriving the structural unit (a) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

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

  As the structural unit (a) derived from the (meth) acrylic monomer having a group represented by the formula (1), preferably the structural unit represented by the formula (a1-1) or the formula (a1-2) Structural units. These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are referred to as the structural unit (a1-1) and the structural unit (a1-2), respectively. There is.

[In Formula (a1-1) and Formula (a1-2),
L ^a3 and L ^a4 each independently represent an oxygen atom or * —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to a carbonyl group. Represent.
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 the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

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

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

  Examples of the monomer that leads to the structural unit (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptane-1- Ile (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-isopropyl And cyclohexane-1-yl (meth) acrylate. Monomers represented by the formula (a1-2-1) to the formula (a1-2-12) are preferred, and the formula (a1-2-3) to the formula (a1-2-4) or the formula (a1-2-9) The monomer represented by formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferable.

  When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually 10 to 95 mol with respect to all the structural units of the resin (A). %, Preferably 15 to 90 mol%, more preferably 20 to 85 mol%, particularly preferably 25 to 70 mol%.

  As the structural unit (a) derived from the (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-3) (hereinafter “structural unit (a1-3)”) ”).

[In the formula (a1-3),
R ^a8 represents a C 1-6 alkyl group optionally having a halogen atom, a hydrogen atom, or a halogen atom.
Z ^a1 represents a single bond or * — [CH ₂ ] _k4 —CO—L ^a8 —. Here, k4 represents an integer of 1 to 4. * Represents a bond with L ^a5 .
L ^a5 , L ^a6 , L ^a7 , and L ^a8 each independently represent an oxygen atom or a sulfur atom.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

In formula (a1-3), R ^a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ^a5 and L ^a8 are preferably oxygen atoms.
One of L ^a6 and L ^a7 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

  Examples of the monomer that leads to the structural unit (a1-3) include the following monomers.

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

  In the resin (A), the content of the structural unit (a) is preferably 10 to 98 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A). Preferably it is 20-80 mol%, Most preferably, it is 25-70 mol%.

<Structural unit without acid labile group>
The resin (A) may have a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”). As the structural unit (s), a structural unit having a hydroxy group or a lactone ring is preferable. However, the structural unit (s) having a lactone ring does not include the structural unit represented by the formula (I). A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When the resist composition is applied to KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV (extreme ultraviolet light), the structural unit (a2) having a phenolic hydroxy group as the structural unit (a2) ) Is preferably used. When applied to ArF excimer laser exposure (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and more preferably a structural unit (a2-1). As the structural unit (a2), one type may be contained alone, or two or more types may be used in combination.

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

[In the formula (a2-1),
L ^a10 represents an oxygen atom or * —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with a carbonyl group.
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 ^a10 is preferably an oxygen atom, —O— (CH ₂ ) _k7 —CO—O— (wherein k7 is an integer of 1 to 4), more preferably It is an oxygen atom.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

  As a monomer which introduce | transduces structural unit (a2-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

  When resin (A) contains structural unit (a2-1), the content rate is 1-60 mol% normally with respect to all the structural units of resin (A), Preferably it is 1-50 mol%. Yes, more preferably 1 to 45 mol%, still more preferably 1 to 40 mol%.

<Structural unit (a3)>
The lactone ring contained in the structural unit (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a bridged ring including these monocyclic lactone ring structures. But you can. Among these lactone rings, a γ-butyrolactone ring or a bridged ring containing a γ-butyrolactone ring structure is preferable.

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

[In the formula (a3-1),
L ^a11 represents an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 are the same or different from each other.
In formula (a3-2),
L ^a12 represents an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 are the same or different from each other.
In formula (a3-3),
L ^a13 represents an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 are the same or different from each other.
In formula (a3-4),
L ^a14 represents an oxygen atom, * —O— (CH ₂ ) _k5 —O—, * —O— (CH ₂ ) _k3 —CO—O—, * —O— (CH ₂ ) _k5 —CO—O— ( CH _{2) k6} -CO-O- or _{* -O- (CH 2) k5 -O} -CO- (CH 2) k6 -O- (k5 and k6 are each independently an integer of 1-7. ) Represents a group represented by * Represents a bond with a carbonyl group.
R ^a24 represents a hydrogen atom or a methyl group. ]

In formula (a3-1) to formula (a3-4), L ^{a11 to} L ^a14 are each independently preferably an oxygen atom or * 3—O— (CH ₂ ) wherein k3 is an integer of 1 to 4. A group represented by _{k 3} —CO—O—, more preferably an oxygen atom and * —O—CH ₂ —CO—O—, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 and R ^a24 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

  Examples of the monomer for deriving the structural unit (a3-1) include the formula (a3-1-1), the formula (a3-1-2), the formula (a3-1-3), and the formula (a3-1-4). And monomers represented by any of the above.

  Examples of the monomer that leads to the structural unit (a3-2) include, for example, the formula (a3-2-1), the formula (a3-2-2), the formula (a3-2-3), and the formula (a3-2-4). And monomers represented by any of the above.

  Examples of the monomer that leads to the structural unit (a3-3) include, for example, the formula (a3-3-1), the formula (a3-3-2), the formula (a3-3-3), and the formula (a3-3-4). And monomers represented by any of the above.

  Examples of the monomer that leads to the structural unit (a3-4) include the formula (a3-4-1), the formula (a3-4-2), the formula (a3-4-3), and the formula (a3-4-4). , A monomer represented by any one of formula (a3-4-5) and formula (a3-4-6).

In the above compound, a compound in which a methyl group corresponding to R ^a24 is replaced with a hydrogen atom can also be exemplified as a monomer for deriving the structural unit (a3-4).

  Among structural units (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-3), formula (a3-2-4), formula (a3-4-) 1) or a structural unit derived from a monomer represented by the formula (a3-4-2) is more preferable, and the formula (a3-1-1), the formula (a3-2-3) or the formula (a3-4-2) The structural unit derived from a monomer represented by

  The structural unit (a3-1), the structural unit (a3-2), and the structural unit (a3-3) can be derived from the monomer (s) described in JP 2010-204646 A.

  The structural unit (a3-4) can be derived from the monomer (s) described in JP2012-41274A.

  When the resin (A) contains the structural unit (a3), the content is usually 70 mol% or less, preferably 65 mol% or less, more preferably, with respect to all the structural units of the resin (A). Is 60 mol% or less, particularly preferably 55 mol% or less. Although the minimum of a structural unit (a3) is not specifically limited, For example, 5 mol% or more or 10 mol% or more may be sufficient.

<Other structural units (s)>
The resin (A) may have other structural units (s). The other structural unit (s) is a structural unit other than the structural unit (a2) and the structural unit (a3), preferably a structural unit having a halogen atom (hereinafter sometimes referred to as “structural unit (a4)”). .).

  As a structural unit (a4), the structural unit represented by a formula (a4-1) is mentioned, for example.

[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
A ^a41 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-g1).

[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an ^optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ^a41 and X ^a42 each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 6 or less. ]
Represents a group represented by
R ^a42 represents an ^optionally substituted hydrocarbon group having 1 to 20 carbon atoms.
However, at least one of A ^a41 and R ^a42 is a group having a halogen atom. ]

Examples of the halogen atom that at least one of A ^a41 and R ^a42 has include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom.
The aliphatic hydrocarbon groups of A ^{a42 to} A ^a44 include chain and cyclic aliphatic hydrocarbon groups and may have a carbon-carbon unsaturated bond, but the aliphatic saturated hydrocarbon group is preferable. The aliphatic saturated hydrocarbon group includes an alkyl group (the alkyl group may be linear or branched), an alicyclic saturated hydrocarbon group, and an alkyl group and an alicyclic saturated hydrocarbon group. And the like.

The hydrocarbon group for R ^a41 is preferably a methyl group.
^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups in which these are combined. Examples of chain aliphatic hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, and hexyl. Examples thereof include alkyl groups such as decyl group, heptadecyl group and octadecyl group. Examples of the cyclic aliphatic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group, a norbornyl group, a decahydronaphthyl group, and the following group (* represents a bond).

^Examples of the aromatic hydrocarbon group for R ^a42 include a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group, and a fluorenyl group.

^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups in which these are combined, and chain and cyclic aliphatic groups. Group hydrocarbon groups and a combination thereof, which may have a carbon-carbon unsaturated bond, are saturated hydrocarbon groups, i.e., chain and cyclic aliphatic saturated hydrocarbon groups, and A combined group is more preferred.
The methylene group contained in the hydrocarbon group for R ^a42 may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the hydrocarbon group may be substituted with a halogen atom. R ^a42 is more preferably an aliphatic hydrocarbon group having a halogen atom and / or a group represented by the formula (a-g3).

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents a C ^1-17 aliphatic hydrocarbon group having at least one halogen atom. ]
R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), including the number of carbon atoms contained in the group represented by the formula (a-g3), fat R ^a42 The total carbon number of the group hydrocarbon group is preferably 15 or less, more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably 1.

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

Suitable R ^a42 , an aliphatic hydrocarbon group having at least one substituent selected from the group consisting of a halogen atom and a group represented by the formula (a-g3) (represented by the formula (a-g2)) Group) will be described in detail.

When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and still more preferably a carbon number. It is a 1-6 perfluoroalkyl group, Most preferably, it is a C1-C3 perfluoroalkyl group. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.

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

  Specific examples of the group represented by the formula (a-g2) include the following groups.

^As the alkanediyl group of ^Aa41 , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group Linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group And branched chain alkanediyl groups such as 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

In the group represented by the formula (a-g1) of A ^a41 (hereinafter sometimes referred to as “group (a-g1)”), A ^a44 is ^bonded to —O—CO—R ^a42 .
^Examples of the aliphatic hydrocarbon group represented by A ^a42 , A ^a43, and A ^{a44 in} the group (a-g1) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, Examples include alkanediyl groups such as butane-1,4-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group. Examples of these substituents 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, among the two bonds represented by *, * on the right side is a bond with —O—CO—R ^a42 .

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 1-10 hydrocarbon group having a fluorine atom. ]

As the alkanediyl group of A ^f1 , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group Linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group And branched chain alkanediyl groups such as 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

The hydrocarbon group for 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 combination thereof. As the aliphatic hydrocarbon group for R ^f2 , an alkyl group and an alicyclic hydrocarbon group are preferable.
Examples of the aliphatic hydrocarbon group represented by R ^f2 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 -Alkyl groups, such as an ethylhexyl group, are mentioned.
The alicyclic hydrocarbon group for R ^f2 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and cyclohexyl. Cycloalkyl groups such as a group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and 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, and norbornyl. Group, methylnorbornyl group and isobornyl group.

Examples of the hydrocarbon group having a fluorine atom for R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Specifically, examples of the alkyl group having a fluorine atom of R ^f2 include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoro. Ethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl)- 1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1 , 2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (pe Fluoropropyl) 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, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2 , 2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoro Examples include fluorinated alkyl groups such as a pentylmethyl group and a perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom of R ^f2 include a perfluorocyclohexyl group and a perfluoroadamantyl group.

In Formula (a4-2), as A ^f1 , an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
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 17 carbon atoms which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

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

The aliphatic hydrocarbon group for A ^f13 includes either a chain or a cyclic group, and a divalent group in which these are combined. The aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, that is, an alkanediyl which may have a fluorine atom. Any of a group and an alicyclic saturated hydrocarbon group which may have a fluorine atom, and a divalent group in which these are combined, more preferably a perfluoroalkanediyl group.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene Groups, perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the divalent monocyclic aliphatic hydrocarbon group which may have a fluorine atom include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the divalent polycyclic divalent aliphatic hydrocarbon group which may have a fluorine atom include an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group, and the like.

As the aliphatic hydrocarbon group for A ^f14 , either a chain or a cyclic group, and an aliphatic hydrocarbon group in which these are combined are included. The 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 for A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, that is, an alkyl group which may have a fluorine atom. And an alicyclic saturated hydrocarbon group which may have a fluorine atom, and a combination thereof.
Examples of the chain aliphatic hydrocarbon group which may have a fluorine atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group and pentyl group, hexyl group, perfluorohexyl group, A heptyl group, a perfluoro heptyl group, an octyl group, a perfluorooctyl group, etc. are mentioned.
Etc.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group which may have a fluorine atom 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 which may have a fluorine atom include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group. Can be mentioned.

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

  Examples of the monomer for deriving the structural unit represented by the formula (a4-2) include monomers represented by the formula (a4-1-1) to the formula (a4-1-22), respectively.

  Examples of the monomer for deriving the structural unit represented by formula (a4-3) include monomers represented by formula (a4-1′-1) to formula (a4-1′-22), respectively.

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

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents — (CH ₂ ) _j1 —, — (CH ₂ ) _j2 —O— (CH ₂ ) _j3 — or — (CH ₂ ) _j4 —CO—O— (CH ₂ ) _j5 —.
j1 to j5 each independently represents an integer of 1 to 6.
R ^f22 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same hydrocarbon groups as R ^f2 in formula (a4-2). R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, more preferably a C 1-10 alkyl group having a fluorine atom. Preferably, the C1-C6 alkyl group which has a fluorine atom is further more preferable.

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

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

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

  The resin (A) may have a structural unit other than the above-described structural unit, and examples of the structural unit include structural units well known in the art.

When the resin (A) is a resin composed only of the structural unit (I) and the structural unit (a), these contents are respectively expressed with respect to all the structural units of the resin (A).
Structural unit (I); 1 to 90 mol%
Structural unit (a); 10-99 mol%
Is preferred,
Structural unit (I); 3 to 80 mol%
Structural unit (a); 20 to 97 mol%
Is more preferred,
Structural unit (I); 5-70 mol%
Structural unit (a); 30-95 mol%
Is more preferable.

When the resin (A) of the present invention is a resin composed of the structural unit (I), the structural unit (a), and the structural unit (s), the content of these is the total structural unit of the resin (A). In contrast,
Structural unit (I); 1-60 mol%
Structural unit (a); 20 to 80 mol%
Structural unit (s); 10-79 mol%
Is preferred,
Structural unit (I); 3 to 50 mol%
Structural unit (a); 25-75 mol%
Structural unit (s); 15-72 mol%
Is more preferred,
Structural unit (I); 5 to 40 mol%
Structural unit (a); 30-65 mol%
Structural unit (s); 20-65 mol%
Is more preferable.
The molar ratio of the structural unit (I) to the structural unit (a) (structural unit (a) / structural unit (I)) is preferably 0.1 to 15, more preferably 0.2 to 10, and 5-8 are more preferable. The molar ratio of the structural unit (I) to the structural unit (s) (structural unit (s) / structural unit (I)) is preferably 0.1 to 10, more preferably 0.2 to 8, 5 is more preferable.

The resin (A) is preferably a resin composed of the structural unit (I), the structural unit (a), and the structural unit (s).
The structural unit (a) is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit (a1- 1).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-1). The structural unit (a3) is preferably at least one of the structural unit (a3-1) and the structural unit (a3-2).

  The resin (A) preferably contains 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 total structural unit (a). 20 mol% or more is more preferable, and 25 mol% or more is further more preferable. When the content of the structural unit having an adamantyl group is large, the dry etching resistance of the resist pattern is improved.

  Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.

  The content of the resin (A) in the resist composition of the present invention is preferably 70% by mass or more and 99% by mass or less, preferably 75% by mass or more and 98% by mass or less, and 80% by mass with respect to the solid content of the resist composition. % To 97% by mass is preferable. In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the resin content relative to the solid content can be measured, for example, by known analytical means such as liquid chromatography or gas chromatography.

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). An example of such a resin is a resin composed of only the structural unit (s).
Among these, as the resin other than the resin (A), a resin having the structural unit (a4) (but not having the structural unit (I)) (hereinafter sometimes referred to as “resin (X)”) is preferable. . In the resin (X), the content ratio of the structural unit (a4) is preferably 30 mol% or more, more preferably 35 mol% or more, still more preferably 40 mol% or more with respect to all the structural units of the resin (X). .
Examples of the structural unit that the resin (X) may further include a structural unit derived from the structural unit (a1), the structural unit (a2), the structural unit (a3), and other known monomers. .

  When the resist composition of this invention contains resin (X), the content becomes like this. Preferably it is 1-60 mass parts with respect to 100 mass parts of resin (A), More preferably, it is 3-50 mass parts More preferably, it is 4-40 mass parts, Most preferably, it is 5-30 mass parts.

<Production method of resin>
Resin (A) is obtained by polymerizing compound (I ′), monomer (a1) and monomer (a2), monomer (a3), and monomer (a4) used as necessary by a known polymerization method (for example, radical polymerization method). Can be manufactured. The content rate of each structural unit which resin (A) has can be adjusted with the usage-amount of the monomer used for copolymerization.
On the other hand, the resin (X) is preferably obtained by subjecting the monomer (a4-1) to polymerization using a known polymerization method, and this polymerization is performed in addition to the monomer (a4-1) and the monomer (a4-1). It may be a copolymer of monomers.

The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less).
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).
Here, the weight average molecular weight is determined as a converted value based on standard polystyrene by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

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

  Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, 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 3914407, European Patent 126,712. A compound capable of generating an acid by radiation described in No. etc. can be used. Moreover, you may use the compound manufactured by the well-known method.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. The hydrogen atom contained may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group of 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, and a perfluoropentyl group. And perfluorohexyl group.
In formula (B1), Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, 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 these A combination of two or more of these groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, etc. Alkanediyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, propane-1,2-diyl group, butane-1, Such as 3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. Branched alkanediyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,2-diyl group, adamantane-1,5-diyl group, adamantane-2,6 -Polycyclic bivalent alicyclic saturated hydrocarbon groups, such as a diyl group.

Specific examples of the group in which the methylene group contained in the saturated hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group are represented by any of formulas (b1-1) to (b1-8), for example. Groups. L ^b1 is preferably a group represented by any one of formula (b1-1) to formula (b1-4) and formula (b1-8), more preferably formula (b1-1) and formula (b1). -3) and a group represented by formula (b1-8). In addition, Formula (b1-1)-Formula (b1-8) have described the right and left according to Formula (B1), and among two bonds represented by *, C (Q ¹ ) Combined with (Q ² ) and combined with Y on the right side. The same applies to specific examples of formula (b1-1) to formula (b1-8) shown below.

In formula (b1-1) to formula (b1-8),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b6 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 15.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 16.
L ^b9 represents a single bond or a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b10 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 14.
L ^b11 and L ^b12 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 12.
L ^b14 and L ^b15 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 14.
L ^b17 represents a single bond or a divalent saturated hydrocarbon group having 1 to 10 carbon atoms.
L ^b18 and L ^b19 each independently represent a divalent saturated hydrocarbon group having 1 to 11 carbon atoms. However, the upper limit of the total carbon number of L ^b17 , L ^b18 and L ^b19 is 12.

  Examples of the divalent group represented by the formula (b1-1) include the following.

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

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

  Examples of the divalent group represented by the formula (b1-4) include the following.

  Examples of the divalent group represented by the formula (b1-5) include the following.

  Examples of the divalent group represented by the formula (b1-6) include the following.

  Examples of the divalent group represented by the formula (b1-7) include the following.

  Examples of the divalent group represented by the formula (b1-8) include the following.

  Examples of the group in which the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom or a hydroxy group include the following divalent groups.

Examples of the alkyl group for Y include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and the like, and preferably an alkyl group having 1 to 6 carbon atoms. .
Examples of the alicyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y11). Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group, or a carbonyl group include groups represented by formulas (Y12) to (Y26). . In the formula, * represents a bond.

  The alicyclic hydrocarbon group of Y is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably formula (Y11), formula (Y14), formula (Y15) or It is group represented by a formula (Y19), More preferably, it is group represented by a formula (Y11) or a formula (Y14).

Examples of the substituent for the alkyl group of Y include, for example, a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, or — (CH ₂ ) _h— O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic carbon atom having 6 to 18 carbon atoms). Represents a hydrogen group, and h represents an integer of 0 to 4.
Examples of the substituent for the alicyclic hydrocarbon group of Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and an aliphatic group having 3 to 16 carbon atoms. A cyclic hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or- (CH ₂ ) _h —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic group having 6 to 18 carbon atoms). And h represents an integer of 0 to 4).

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

In addition, when Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated carbonization at the bonding position with Y The methylene group of the hydrogen group is preferably replaced with an oxygen atom or a carbonyl group. In this case, the methylene group contained in the alkyl group of Y is not replaced with an oxygen atom or a carbonyl group. The same applies when the hydrogen atom contained in the alkyl group of Y and / or the divalent linear or branched saturated hydrocarbon group of L ^b1 is substituted with a substituent.

  Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably a substituent (for example, an oxo group, a hydroxy group, etc.). An adamantyl group, more preferably an adamantyl group, a hydroxyadamantyl group, or an oxoadamantyl group.

The sulfonate anion in the salt (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9) [hereinafter referred to as “anion (b1-1] according to the formula number”). -1) ". ]. In the following formulas, the definitions of Q ¹ , Q ² and L ^{b2 have} the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group). Represent.
Specific examples of the sulfonate anion in the salt (B1) include anions described in JP 2010-204646 A.

In the formula (B1), examples of the organic cation of Z ⁺ include an organic onium cation, such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. It is a cation or an organic iodonium cation, and more preferably an arylsulfonium cation.
Z ⁺ in formula (B1) is preferably a cation represented by any one of formula (b2-1) to formula (b2-4) [hereinafter referred to as “cation (b2-1)” or the like depending on the formula number, etc. There is a case. ].

In formula (b2-1),
R ^{b4 to} R ^b6 each independently represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon The hydrogen atom contained in the group may be substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group The atom may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may together form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with the sulfur atom to which they are bonded.

In formula (b2-2),
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.

In formula (b2-3),
R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may together form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with the sulfur atom to which they are bonded. The methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, and the aliphatic hydrocarbon group includes The contained hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is an alkoxy group having 1 to 12 carbon atoms or 1 carbon atom. It may be substituted with ˜12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) together with —CH—CO— to which they are bonded. The methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group.

In formula (b2-4),
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When q2 is 2 or more, the plurality of R ^b15 is When r2 is 2 or more, a plurality of R ^b16 may be the same or different. When s2 is 2 or more, a plurality of R ^b17 may be the same or different, and t2 is 2 or more. Sometimes, the plurality of R ^b18 may be the same or different.

^Examples of the aliphatic hydrocarbon group ^{represented by} R ^{b4 to} R ^b18 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group. And alkyl groups such as 2-ethylhexyl group. In particular, the aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms.
The alicyclic hydrocarbon group for R ^{b4 to} R ^b6 and R ^{b9 to} R ^b12 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group is an alkyl group. May be substituted. In this case, the carbon number of the alicyclic hydrocarbon group includes the carbon number of the alkyl group, and is preferably 20 or less. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.

In particular, the alicyclic hydrocarbon group of R ^{b4 to} R ^b6 preferably has 3 to 18 carbon atoms. The alicyclic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

Examples of the alicyclic hydrocarbon group in which the hydrogen atoms of R ^{b4 to} R ^b6 are substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, and a methylnorbornyl group. Group, isobornyl group and the like.

^Examples of the aromatic hydrocarbon group represented by R ^{b4 to} R ^b6 , R ^b11 and R ^b12 include a phenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, and a p-tert-butylphenyl group. , P-cyclohexylphenyl group, p-adamantylphenyl group, biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group. The aromatic hydrocarbon group also includes an aryl group in which an aromatic hydrocarbon group or an alicyclic hydrocarbon group is bonded to an aromatic ring. In this case, the number of carbon atoms is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group. The number of carbons in the group can also be counted. The aromatic hydrocarbon group of R ^{b4 to} R ^b6 preferably has 6 to 24 carbon atoms. The aromatic hydrocarbon group for R ¹¹ and R ¹² preferably has 6 to 18 carbon atoms.
^Examples of the aromatic hydrocarbon group in which the hydrogen atoms of R ^{b4 to} R ^b6 and R ^b12 are substituted with an alkoxy group include a methoxyphenyl group, an ethoxyphenyl group, a propoxyphenyl group, a butoxyphenyl group, a pentyloxyphenyl group, and a hexyl group. Examples thereof include an oxyphenyl group, a heptyloxyphenyl group, a tritylphenyl group, a naphthylmethylphenyl group, and a naphthylethylphenyl group.
Examples of the aromatic hydrocarbon group in which the hydrogen atoms of R ^{b4 to} R ^b6 are substituted with halogen atoms include a fluorophenyl group, a chlorophenyl group, a bromophenyl group, and an iodophenyl group.
Examples of the aromatic hydrocarbon group in which the hydrogen atoms of R ^{b4 to} R ^b6 are substituted with a hydroxy group include a hydroxyphenyl group.
^Examples of the aromatic hydrocarbon group in which the hydrogen atom of R ^b12 is substituted with an alkylcarbonyloxy group include a methylcarbonyloxyphenyl group, an ethylcarbonyloxyphenyl group, an n-propylcarbonyloxyphenyl group, an isopropylcarbonyloxyphenyl group, an n- Examples include butylcarbonyloxyphenyl group, sec-butylcarbonyloxyphenyl group, tert-butylcarbonyloxyphenyl group, pentylcarbonyloxyphenyl group, hexylcarbonyloxyphenyl group, octylcarbonyloxyphenyl group, and 2-ethylhexylcarbonyloxyphenyl group. It is done.
Examples of the alkyl group in which the hydrogen atoms of R ^{b4 to} R ^b6 are substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. It is done.

^Examples of the alkoxy group of R ^b7 , R ^b8 , R ^{b13 to} R ^b18 include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group Groups and the like.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom that may replace the hydrogen atom of the alkyl group represented by R ^{b4 to} R ^b6 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The ring containing a sulfur atom which may be formed by combining R ^b4 and R ^b5 is any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. If it contains one or more sulfur atoms, it may further contain one or more sulfur atoms and / or one or more oxygen atoms. As the ring, a ring having 3 to 18 carbon atoms is preferable, and a ring having 4 to 18 carbon atoms is more preferable.

Examples of the ring formed together with the sulfur atom to which R ^b9 and R ^b10 are bonded include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium. A ring etc. are mentioned.
Examples of the ring formed with —CH—CO— in which R ^b11 and R ^b12 are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  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.

Among the cation (b2-1) to cation (b2-4), the cation (b2-1) is preferable, more preferably a cation represented by the formula (b2-1-1) (hereinafter referred to as “cation ( more preferably triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (formula In (b2-1-1), v2 = w2 = 0, x2 = 1, R ^b21 is a methyl group, diphenyl (4-tert-butylphenyl) sulfonium cation (formula (b2-1-1) ) in a v2 = w2 = 0, x2 = 1, R b21 is a tert- butyl group.), in phenyldi (4-tert- butylphenyl) sulfonium cation (formula (b2-1-1), v = A 0, w2 = x2 = 1, R b20 and R ^b21 are tert- butyl group.), In tritolyl sulfonium cation (formula (b2-1-1), be v2 = w2 = x2 = 1 , R ^b19 , R ^b20 and R ^b21 are all methyl groups) or tri (4-tert-butylphenyl) sulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1 , R ^b19 , R ^b20 and R ^b21 are all tert-butyl groups.

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 3 to 18 carbon atoms. Represents an 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 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different, when w2 is 2 or more, the plurality of R ^b20 are the same or different, and when x2 is 2 or more, the plurality of R ^b21 are the same or different. .

Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. It is.

  Specific examples of the cation represented by the formula (b2-1-1) include cations described in JP 2010-204646 A.

  The salt (B1) is a combination of the above sulfonic acid anion and the above organic cation. These can be arbitrarily combined, and preferably a combination of any one of anion (b1-1-1) to anion (b1-1-9) with a cation (b2-1-1), and an anion (b1- The combination of any of 1-3)-anion (b1-1-5) and a cation (b2-3) is mentioned.

  As the salt (B1), those represented by formulas (B1-1) to (B1-24) are more preferable, and formulas (B1-1) and (B1-2) containing an arylsulfonium cation are preferable. ), 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 (B1-20), formula (B1-21), formula (B1-22), formula (B1-23) and formula (B1-24), respectively. preferable.

The content of the salt (B1) is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less with respect to the total amount of the acid generator (B). More preferably, only
The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part or less).
In the resist composition of the present invention, the acid generator (B) may contain one kind alone or plural kinds.

  It is preferable that the resist composition of the present invention further contains a solvent (E).

<Solvent (E)>
The content of the solvent (E) is, for example, 80% by mass or more in the resist composition, preferably 85% by mass or more, more preferably 90% by mass or more, for example, 99.9% by mass or less, preferably 99% by mass or less. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and pyruvic acid Examples thereof include esters such as ethyl; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

  The resist composition of the present invention preferably further contains a compound represented by formula (II) (hereinafter sometimes referred to as “compound (II)”) and / or a basic compound (C).

<Compound (II)>
Compound (II) is represented by Formula (II).

[In the formula (II),
R ^D1 and R ^D2 are each independently a 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, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represent an integer of 0 to 4, and when m ′ is 2 or more, the plurality of R ^D1 are the same or different, and when n is 2 or more, the plurality of R ^D2 are the same. Or different. ]

In the compound (II), examples of the hydrocarbon group of R ^D1 and R ^D2 include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and combinations thereof.
Examples of the aliphatic hydrocarbon group represented by R ^D1 and R ^D2 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and nonyl group. Can be mentioned.
The alicyclic hydrocarbon group for R ^D1 and R ^D2 may be monocyclic or polycyclic, and may be either saturated or unsaturated, but is preferably an alicyclic saturated hydrocarbon group. Examples of the alicyclic saturated hydrocarbon group for R ^D1 and R ^D2 include a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclononyl group, and a cyclododecyl group, a norbornyl group, and an adamantyl group. Etc.
Examples of the aromatic hydrocarbon group of R ^D1 and R ^D2 include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, and a 4-ethylphenyl group. 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group , Aryl groups such as xylyl group, cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
R ^D1 and R ^D2 , which are a combination of two or more aliphatic hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, and aralkyl groups. (For example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl- 1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.).

^Examples of the alkoxy group for R ^D1 and R ^D2 include a methoxy group and an ethoxy group.
Examples of the acyl group for R ^D1 and R ^D2 include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group.
Examples of the acyloxy group for R ^D1 and R ^D2 include a group in which an oxy group (—O—) is bonded to the acyl group.
Examples of the alkoxycarbonyl group of R ^D1 and R ^D2 include a group in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom for R ^D1 and R ^D2 include a fluorine atom, a chlorine atom, and a bromine atom.

R ^D1 and R ^D2 in formula (II) are each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkyl group having 2 to 4 carbon atoms. An acyl group, 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, the plurality of R ^D1 are the same or different, and when n ′ is 2 or more, the plurality of R ^D2 are the same or different.

  Examples of the compound (II) include the following compounds.

  Compound (II) can be produced by the method described in “Tetrahedron Vol. 45, No. 19, p6281-6296”. Compound (II) may be a commercially available compound.

  When the resist composition of this invention contains compound (II), 0.01-12 mass parts is preferable with respect to 100 mass parts of resin (A), and content of compound (II) is 0.03-10. A mass part is more preferable and 0.06-6 mass parts is still more preferable. The content ratio of compound (II) is preferably 0.01 to 10% by mass, more preferably 0.03 to 8% by mass, and still more preferably 0% with respect to the solid content of the resist composition. 0.05 to 5% by mass.

<Basic compound (C)>
The basic compound means a compound having a property of capturing an acid, particularly a compound having a property of capturing an acid generated from an acid generator, and is called a quencher in the technical field.
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. Preferred examples of the basic compound (C) include compounds represented by the formulas (C1) to (C8) and the formula (C1-1), and more preferred are compounds represented by the formula (C1-1). Is mentioned.

[In formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 18 represents an aromatic hydrocarbon group, the hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 6 carbon atoms. ]

  The compound represented by the formula (C1) is preferably a compound represented by the formula (C1-1).

[In Formula (C1-1), R ^c4 and R ^c5 represent the same meaning as described above.
R ^c6 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c6 are the same or different. ]

[In Formula (C2), Formula (C3) and Formula (C4), R ^c7 , R ^c8 , R ^c9 and R ^c10 each independently represent the same meaning as R ^c1 .
R ^c11 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c11 are the same or different. ]

[In Formula (C5) and Formula (C6), R ^c12 , R ^c13 , R ^c14 , R ^c15 and R ^c18 each independently represent the same meaning as R ^c1 .
R ^c16 , R ^c17 and R ^c19 each independently represent the same meaning as R ^c6 .
o3 and p3 each independently represent an integer of 0 to 3, when o3 is 2 or more, the plurality of R ^c16 are the same or different, and when p3 is 2 or more, the plurality of R ^c17 are the same or Different.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, a carbonyl group, —C (═NH) —, a sulfur atom, or a divalent group obtained by combining these. ]

Wherein (C7) and formula ^{(C8), R c20, R} c21 and R ^c22 are each independently the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c20 are the same or different, and when r3 is 2 or more, the plurality of R ^c19 are the same. Or when different and when s3 is 2 or more, the plurality of R ^c22 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, a carbonyl group, —C (═NH) —, a sulfur atom, or a divalent group obtained by combining these. ]

In formula (C1) to formula (C8) and formula (C1-1), the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group, alkanediyl group are the same as those described above. Is mentioned.
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

  Examples of the compound represented by the formula (C1) 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, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

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

  When the basic composition (C) is contained in the resist composition of the present invention, the content of the basic compound (C) is preferably about 0.01 to 5% by mass in the solid content of the resist composition. More preferably, it is about 0.01-3 mass%, Especially preferably, it is about 0.01-1 mass%.

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

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A), an acid generator (B), a resin other than the resin (A) used as necessary, a solvent (E), a basic compound (C), a compound (II ) And other components (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to the solvent (E), such as a kind, etc. of resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

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

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

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

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

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds.

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

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

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

<Application>
The resist composition of the present invention is 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 a liquid. It is suitable as a resist composition for immersion exposure and useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The structure of the compound was confirmed by MASS (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore (registered trademark) HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

Synthesis Example 1 [Synthesis of Compound Represented by Formula (I-1)]

10 parts of a compound represented by the formula (I-1-1), 9.87 parts of a compound represented by the formula (I-1-2), 45 parts of tetrahydrofuran and 6.00 parts of triethylamine were charged at 30 ° C. and 30 parts. After stirring and mixing for minutes, the mixture was cooled to 0 ° C. While maintaining the same temperature, 15.76 parts of the compound represented by the formula (I-1-3) is added to the obtained mixture, and the temperature is further increased to about 25 ° C., and tert-butyl methyl ether 200 is added. Part was added and stirred at 23 ° C. for 18 hours. To the obtained reaction product, 150 parts of a 2% hydrochloric acid aqueous solution was added and stirred at 23 ° C. for 30 minutes. To the organic layer recovered by standing and separating, 45 parts of 10% aqueous potassium carbonate solution was added, stirred at 23 ° C. for 30 minutes, and allowed to stand and separate to wash the organic layer. Such washing operation was repeated twice. The organic layer after washing was charged with 80 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such washing operation was repeated 5 times. The organic layer after washing with water was concentrated to obtain 8.01 parts of a compound represented by the formula (I-1).
MS (mass spectrometry): 270.1 (molecular ion peak)

Synthesis Example 2 [Synthesis of Compound Represented by Formula (I-6)]

1.02 parts of a compound represented by the formula (I-6-1) and 10 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes to obtain 1.10 parts of a compound represented by the formula (I-6-2). The mixture was charged and stirred at 60 ° C. for 1 hour. The obtained reaction product was cooled to 23 ° C. and filtered to obtain a solution containing the compound represented by the formula (I-6-3). A solution containing the compound represented by the formula (I-6-3) was charged with 1.78 parts of the compound represented by the formula (I-6-4) and stirred at 60 ° C. for 2 hours. After concentrating the obtained reaction product, 20 parts of chloroform and 10 parts of ion-exchanged water were added to the obtained residue, followed by stirring and liquid separation. Subsequently, washing with water was performed 5 times. The organic layer after washing with water was concentrated to obtain 1.56 parts of a compound represented by the formula (I-6).
MS (mass spectrometry): 420.2 (molecular ion peak)

Synthesis Example 3 [Synthesis of Compound Represented by Formula (I-7)]

1.02 parts of a compound represented by the formula (I-7-1) and 10 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes to obtain 1.10 parts of a compound represented by the formula (I-7-2). The mixture was charged and stirred at 60 ° C. for 1 hour. The obtained reaction product was cooled to 23 ° C. and filtered to obtain a solution containing a compound represented by the formula (I-7-3). A solution containing the compound represented by the formula (I-7-3) was charged with 1.68 parts of the compound represented by the formula (I-7-4) and stirred at 60 ° C. for 2 hours. After concentrating the obtained reaction product, 20 parts of chloroform and 10 parts of ion-exchanged water were added to the obtained residue, followed by stirring and liquid separation. Subsequently, washing with water was performed 5 times. The organic layer after washing with water was concentrated to obtain 1.44 parts of a compound represented by the formula (I-7).
MS (mass spectrometry): 404.2 (molecular ion peak)

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

  Hereinafter, these monomers are referred to as “monomer (a1-1-2)” or the like according to the formula number.

Synthesis Example 4 [Synthesis of Resin A1]
As the monomer, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (I-1) were used, The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (I-1)] is 45:14: It mixed so that it might become 2.5: 22: 16.5, and the propylene glycol monomethyl ether acetate of 1.5 mass times of the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was stirred in methanol and filtered to obtain a resin A1 (copolymer) having a weight average molecular weight of 8.2 × 10 ^{3 in} a yield of 71%. This resin A1 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A2]
As the monomer, monomer (a1-1-1), monomer (a2-1-1) and monomer (I-1) were used, and the molar ratio [monomer (a1-1-1): monomer (a2-1-1) ): Monomer (I-1)] was mixed at 40:30:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was stirred in methanol and filtered to obtain Resin A2 (copolymer) having a weight average molecular weight of 8.3 × 10 ^{3 in} a yield of 70%. This resin A2 has the following structural units.

Synthesis Example 6: [Synthesis of Resin A3]
Monomer (a1-1-3), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-2-3) and monomer (I-1) are mixed in a molar ratio [monomer ( a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (I-1)] is 34: 8: 8: 34 : 16 was mixed, and further, 1.5 mass times dioxane was mixed with this monomer mixture with respect to the total mass of all monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were respectively added to 1.00 mol% and 3.00 mol% with respect to the total number of moles of all monomers. It added so that it might become. This was polymerized by heating at 73 ° C. for about 5 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. It is again dissolved in dioxane, poured into a mixed solvent of a large amount of methanol and water to precipitate the resin, and the precipitated resin is filtered and collected twice to perform reprecipitation purification, and the weight average molecular weight is 8 Resin A3 (copolymer) of 1 × 10 ³ was obtained with a yield of 68%. This resin A3 has the following structural units.

Synthesis Example 7 [Synthesis of Resin A4]
As a monomer, the monomer (a1-1-3), the monomer (a1-2-9), the monomer (a2-1-3), the monomer (a3-2-3) and the monomer (I-6) The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (I-6)] is 45:14: It mixed so that it might become 2.5: 22: 16.5, and the propylene glycol monomethyl ether acetate of 1.5 mass times of the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was stirred in methanol and filtered to obtain Resin A4 (copolymer) having a weight average molecular weight of 7.8 × 10 ^{3 in} a yield of 64%. This resin A4 has the following structural units.

Synthesis Example 8 [Synthesis of Resin A5]
As the monomer, the monomer (a1-1-3), the monomer (a1-2-9), the monomer (a2-1-3), the monomer (a3-2-3) and the monomer (I-7) The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (I-7)] is 45:14: It mixed so that it might become 2.5: 22: 16.5, and the propylene glycol monomethyl ether acetate of 1.5 mass times of the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was stirred in methanol and filtered to obtain a resin A5 (copolymer) having a weight average molecular weight of 7.9 × 10 ^{3 in} a yield of 62%. This resin A5 has the following structural units.

Synthesis Example 9 [Synthesis of Resin H1]
As the monomer, monomer (a1-1-1), monomer (a2-1-1) and monomer (IX) are used, and the molar ratio [monomer (a1-1-1): monomer (a2-1-1): Monomer (IX)] was mixed at 40:30:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was stirred in methanol and filtered to obtain a resin H1 (copolymer) having a weight average molecular weight of 8.1 × 10 ^{3 in} a yield of 68%. This resin H1 has the following structural units.

Synthesis Example 10: [Synthesis of Resin H2]
The monomer (a1-1-3), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-1-1) and the monomer (a3-2-3) are mixed in a molar ratio [ Monomer (a1-1-3): Monomer (a1-2-3): Monomer (a2-1-1): Monomer (a3-2-3): Monomer (a3-1-1)] is 34: 8 : 8: 34: 16 The mixture was further mixed, and 1.5 mass times of dioxane was further mixed with this monomer mixture with respect to the total mass of all monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were respectively added to 1.00 mol% and 3.00 mol% with respect to the total number of moles of all monomers. It added so that it might become. This was polymerized by heating at 73 ° C. for about 5 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. Again, it is dissolved in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and collected twice to perform reprecipitation purification, and the weight average molecular weight is 7 Resin H2 (copolymer) of .8 × 10 ³ was obtained in a yield of 72%. This resin H2 has the following structural units.

Synthesis Example 11 [Synthesis of Resin X1]
Monomer (a4-1-7) was used as a monomer, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 0.7 mol% and 2.1 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered.
The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice to perform the reprecipitation operation twice. 8 × 10 ⁴ of resin X1 was obtained with a yield of 77%. This resin X1 has the following structural units.

Synthesis Example 12 [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, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and then 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 13 [Synthesis of salt represented by formula (B1-23)]

  5.00 parts of the compound represented by the formula (B1-23-a) and 25 parts of dimethylformamide were charged into a reactor and stirred at 23 ° C. for 30 minutes. Then, 3.87 parts of triethylamine was added dropwise, and further 23 ° C. For 30 minutes. A solution obtained by dissolving 6.14 parts of the compound represented by the formula (B1-23-b) in 6.14 parts of dimethylformamide was added dropwise to the obtained mixture over 30 minutes, and the mixture was further stirred at 23 ° C. for 2 hours. did. 25 parts of ion-exchanged water and 150 parts of ethyl acetate were added to the resulting reaction solution, and the mixture was stirred at 23 ° C. for 30 minutes, and then separated to recover the organic layer. The recovered organic layer was charged with 75 parts of ion-exchanged water and stirred at 23 ° C. for 30 minutes, followed by liquid separation to recover the organic layer. This washing operation was further performed 5 times. The obtained organic layer is concentrated, and 92.20 parts of n-heptane is added to the resulting concentrate, followed by stirring, followed by filtration to obtain a compound 2 represented by the formula (B1-23-c). .69 parts were obtained.

A salt represented by the formula (B1-23-d) was synthesized by the method described in JP 2008-127367 A.
2.99 parts of a salt represented by the formula (B1-23-d) and 15.00 parts of acetonitrile are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-23-e). 1.30 parts of compound was charged and stirred at 70 ° C. for 2 hours. The obtained reaction product was cooled to 23 ° C. and then filtered to obtain a solution containing a compound represented by the formula (B1-23-f). A solution containing the compound represented by formula (B1-23-f) was charged with a solution prepared by dissolving 2.12 parts of the compound represented by formula (B1-23-c) in 6.36 parts of chloroform, For 23 hours. The obtained reaction product was concentrated, and 60 parts of chloroform and 30 parts of a 2% oxalic acid aqueous solution were added to the resulting concentrate, followed by stirring and liquid separation. This oxalic acid aqueous solution was washed twice. To the recovered organic layer, 30 parts of ion-exchanged water was added, and the mixture was stirred and separated. Water washing was performed 5 times. The obtained organic layer was concentrated, and the resulting concentrate was dissolved in 30 parts of acetonitrile and then concentrated. To the obtained concentrate, 50 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile, and concentrated to obtain 3.46 parts of the salt represented by the formula (B1-23).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ⁻ 517.2

Examples 1 to 7 and Comparative Examples 1 and 2
<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1 to A5, H1, H2, X1: Resin A1 to Resin A5, Resin H1, Resin H2, Resin X1
<Acid generator>
B1-5: salt represented by formula (B1-5) B1-23: salt represented by formula (B1-23) BX: bis (4-t-butylphenyl) iodonium nonafluorobutanesulfonate (Wako Pure Chemical Industries, Ltd.) Manufactured by Kogyo Co., Ltd.)
B1-2: salt represented by the formula (B1-2): synthesized according to the examples of JP-A-2006-257078

<Compound (II)>
II1: (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

Examples 1 to 7 and Comparative Examples 1 and 2
<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer, and baked under the conditions of 205 ° C. and 60 seconds, whereby an organic layer having a thickness of 78 nm was obtained. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 100 nm. After coating, the composition layer was formed on the silicon wafer by pre-baking on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 1. ArF excimer laser stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annular σ = 0.9 / 0.7 XY polarized light) on the composition layer formed on the silicon wafer, Using a mask for forming a line-and-space pattern (pitch 90 nm / line width 45 nm), exposure was carried out while changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium. After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

<Shape evaluation>
The cross-sectional shape of a 45 nm line and space pattern manufactured with effective sensitivity was observed with a scanning electron microscope. The top shape and skirt shape are close to a rectangle with good shape [Figure 1 (a)]. The top shape and skirt shape are close to a rectangle and generally good, but the top shape tends to be slightly T-shaped. The case where the top shape is round [FIG. 1 (b)] or the shape close to the T-shape [FIG. 1 (c)], or the bottom is seen [FIG. 1 (d)] is determined as x. . The results are shown in Table 2.

  From the above results, it can be seen that according to the resist composition of the present invention, a negative resist pattern can be produced with an excellent shape.

  Since the resist composition of the present invention has an excellent resist pattern shape, it is suitable for semiconductor microfabrication and is industrially useful.

Claims (2)

A resin containing a structural unit represented by formula (I) and a structural unit having an acid labile group, and an acid generator ,
A resist composition, wherein L ^{1 in the} formula (I) is a group represented by the formula (L1-4) .


[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom .
R ² represents an alkyl group having 1 to 6 carbon atoms.
m represents an integer of 0 to 5, and when m is 2 or more, the plurality of R ² are the same or different .
In formula (L1-4),
X ^x3 represents a carbonyloxy group or an oxycarbonyl group.
L ^x8 and L ^x9 represent a single bond or a divalent chain 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.
* Represents a bond with an oxygen atom.
The bond on the right side of X ^x3 is directly bonded to the lactone ring. ] (1) The process of apply | coating the resist composition of Claim 1 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including: