JP6306852B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

In Patent Document 1, a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-B), a structural unit represented by the formula (u-C), and a formula A resist composition containing a resin composed of a structural unit represented by (u-D) and a structural unit represented by formula (u-B) and an acid generator is described.

JP 2010-197413 A

  In the conventional resist composition, the focus margin (DOF) at the time of manufacturing the resist pattern may not always be sufficiently satisfied.

The present invention includes the following inventions.
[1] A resin having a structural unit represented by formula (I) and a structural unit represented by formula (a4) and having no acid labile group,
A resin having an acid labile group, and
A resist composition containing an acid generator represented by the formula (II).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group or hydroxy group having 1 to 8 carbon atoms. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ¹ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ¹ represents a single bond or a C 1-18 divalent saturated hydrocarbon group, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]
[In the formula (a4),
R ³ represents a hydrogen atom or a methyl group.
R ⁴ represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]
[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹¹ represents * —CO—O—L ^a — or * —CH ₂ —O—L ^b —. * Represents a bond with -C (Q ¹ ) (Q ² )-.
L ^a represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, a methylene group contained in the saturated hydrocarbon group of the divalent may be replaced by an oxygen atom or a carbonyl group.
L ^b represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms, and the methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ represents a heterocyclic ring having 2 to 36 carbon atoms.
Z1 ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein R ² in formula (I) is an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms.
[3] The resist composition according to [1] or [2], wherein the structural unit represented by the formula (a4) is a structural unit represented by the formula (a4-0).
[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]
[4] A structure represented by the formula (I) in a resin having the structural unit represented by the formula (I) and the structural unit represented by the formula (a4) and having no acid labile group. The content rate of the unit is based on the total structural unit of the resin having the structural unit represented by the formula (I) and the structural unit represented by the formula (a4) and having no acid labile group. The resist composition according to any one of [1] to [3], which is 25 to 75 mol%.
[5] The resin having an acid labile group is a resin containing at least one selected from the group consisting of a structural unit represented by the formula (a1-1) and a structural unit represented by the formula (a1-2). The resist composition according to any one of [1] to [4].
[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]
[6] L ¹¹ in the formula (II) is * —CO—O—L ^a — (L ^a represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms, and * represents —C (Q ¹ ) ( Q ² ) represents a bond with-.) The resist composition according to any one of [1] to [5].
[7] (1) A step of applying the resist composition according to any one of [1] to [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a resist pattern can be produced with an excellent focus margin (DOF). In addition, the number of defects in the obtained resist pattern can be reduced.

In the present specification, unless otherwise specified, in the description of the structural formula of a compound, “aliphatic hydrocarbon group” means a linear or branched hydrocarbon group, and “alicyclic hydrocarbon group” means A group obtained by removing a number of hydrogen atoms corresponding to the valence from the ring of an alicyclic hydrocarbon. The “aromatic hydrocarbon group” also includes a group in which a hydrocarbon group is bonded to an aromatic ring. When stereoisomers exist, all stereoisomers are included.
Further, "(meth) acrylic monomer" means at least one monomer having a structure of "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- ". Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resist composition>
The resist composition of the present invention contains a resin (hereinafter sometimes referred to as “resin (A)”) and an acid generator (hereinafter sometimes referred to as “acid generator (B)”).
It is preferable that the resist composition of the present invention further contains a solvent (E).
Further, it preferably contains a basic compound (C).

<Resin (A)>
The resin (A) contained in the resist composition of the present invention is
Resin having the structural unit represented by the above formula (I) and the structural unit represented by the formula (a4) and having no acid labile group (hereinafter, referred to as “resin (A1)”) ), And
A resin having an acid labile group (hereinafter sometimes referred to as “resin (A2)”) is included.
In the present specification, the “acid labile group” is a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid. Means.
The resin (A) may further contain a resin other than the resins (A1) and (A2) as described later.

<Resin (A1)>
Resin (A1) includes a structural unit represented by formula (I) (hereinafter sometimes referred to as “structural unit (I)”) and a structural unit represented by formula (a4) (hereinafter referred to as “structural unit (a4)”). May have). Further, unless the resin (A1) has an acid labile group, that is, unless it has a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”), One or more structural units having no acid labile group, which will be described later (hereinafter sometimes referred to as “structural unit (s)”) may be contained.

<Structural unit (I)>
The resin (A1) has the structural unit (I).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group or hydroxy group having 1 to 8 carbon atoms. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ¹ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ¹ represents a single bond or a C 1-18 divalent saturated hydrocarbon group, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

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

Examples of the divalent saturated hydrocarbon group for L ¹ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. .
Examples of the divalent aliphatic saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

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

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

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

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

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

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

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

Examples of the structural unit (I) include those listed below and those listed below for the structural unit (a2-1).

In the above structural unit, a structural unit in which the methyl group corresponding to R ¹ is replaced by a hydrogen atom can also be given as a specific example 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 formula (I ′), R ¹ , R ² and L ¹ represent the same meaning as described above. ]

Compound (I ′) may be a commercially available product or one produced by a known method. Here, the known method includes, for example, a method of condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride etc.) and alcohol (HO-L ¹ -R ² ). . Commercially available products include adamantane-1-yl methacrylate and adamantane-1-yl acrylate.

<Structural unit (a4)>
The resin (A1) has a structural unit (a4).
[In the formula (a4),
R ³ represents a hydrogen atom or a methyl group.
R ⁴ represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]

Examples of the saturated hydrocarbon group having a fluorine atom for R ⁴ include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -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- (perfluoro Propyl) 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, perfluoropentyl Examples thereof include fluorinated alkyl groups such as a methyl group and a perfluorohexyl group; and alicyclic hydrocarbon groups having a fluorine atom such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

The structural unit (a4) is preferably a structural unit represented by the formula (a4-0).
[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

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

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

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

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

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

Compound (a4 ′) may be a commercially available product or one produced by a known method. Here, the known method includes, for example, a method of condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride etc.) and alcohol (HO-R ⁴ ). As a commercial item, the compound etc. which are represented by the following are mentioned.

The content of the structural unit (I) in the resin (A1) is preferably from 25 to 80 mol%, more preferably from 25 to 75 mol%, more preferably from 30 to 70 mol%, based on all the structural units of the resin (A1). Is more preferable, and 40 to 60 mol% is particularly preferable.
The content of the structural unit (a4) in the resin (A1) is preferably 20 to 75 mol%, more preferably 25 to 75 mol%, and more preferably 30 to 70 mol% with respect to all the structural units of the resin (A1). Is more preferable, and 40 to 80 mol% is particularly preferable.
The total content of the structural unit (I) and the structural unit (a4) is preferably 50 mol% or more, more preferably 70 mol% or more, and more preferably 90 mol% or more with respect to all the structural units of the resin (A1). It is particularly preferable that substantially only the structural unit (I) and the structural unit (a4) are present.
When the content of the structural unit (I) and the structural unit (a4) is within the above range, a resist pattern with an excellent focus margin (DOF) can be manufactured, and in particular, a resist pattern with few defects can be manufactured. .

Each structural unit (I) and structural unit (a4) constituting the resin (A1) can be used alone or in combination of two or more. Resin (A1) can be manufactured by a well-known polymerization method (for example, radical polymerization method) combining only 1 type or 2 types or more of compound (I ') and compound (a4'), respectively. The content rate of each structural unit which resin (A1) has can be adjusted with the usage-amount of the compound used for superposition | polymerization.
The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 7,000 or more, more preferably 10,000 or more), 80,000 or less (more preferably 50,000 or less, further preferably Is 30,000 or less). A weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.

The resin (A1) may have a structural unit different from the structural unit (I) and the structural unit (a4).
The structural unit different from the structural unit (I) and the structural unit (a4) includes a structural unit represented by the formula (a4-1), a structural unit represented by the formula (a4-2), and a formula (a4-3). ), Structural units derived from known monomers used in the field, and the like. The structural unit represented by the formula (a4-1) may be referred to as “structural unit (a4-1)” or the like depending on the formula number.
[In the formula (a4-1),
R ^f3 represents a hydrogen atom or a methyl group.
L ^{3 ′} represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^f4 represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]
[In the formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ^{4 ′} represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^f6 represents a hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]
[In the formula (a4-3),
R ^f7 represents a hydrogen atom or a methyl group.
L ^{5 ′} represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a C 1-18 divalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom. ]
However, the total number of carbon atoms of L ^{5 ′} , A ^f13 and A ^f14 is 20.

Examples of the alkanediyl group of L ^{5 ′} include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Linear alkanediyl groups such as diyl group, hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane- Examples include branched alkanediyl groups such as 1,2-diyl group, 1-methylbutane-1,4-diyl group, and 2-methylbutane-1,4-diyl group.

The divalent saturated hydrocarbon group for A ^f13 is, for example, an aliphatic saturated hydrocarbon group or an alicyclic saturated hydrocarbon group.
The saturated hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group.
Examples of the divalent aliphatic saturated 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 group, Examples thereof include perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent alicyclic saturated hydrocarbon group which may have a fluorine atom may be monocyclic or polycyclic. Examples of the monocyclic divalent alicyclic saturated hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

The saturated hydrocarbon group for A ^f14 is, for example, an aliphatic saturated hydrocarbon group or an alicyclic saturated hydrocarbon group.
Examples of the aliphatic saturated hydrocarbon group which may have a fluorine atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1,2, , 2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4 , 4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group and pentyl group, hexyl group, perfluorohexyl group, heptyl group Perfluoroheptyl group, octyl group and perfluorooctyl group.
The alicyclic saturated hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, and a perfluorocyclohexyl group. Examples of the polycyclic alicyclic saturated hydrocarbon group include an adamantyl group, a norbornyl group, a perfluoroadamantyl group, and the like.
Examples of the group in which an aliphatic saturated hydrocarbon group and an alicyclic saturated hydrocarbon group are combined include an adamantylmethyl group, a norbornylmethyl group, a perfluoroadamantylmethyl group, and the like.

In formula (a4-3), L ^{5 ′} is preferably an ethylene group.
A ^f13 is preferably an aliphatic saturated hydrocarbon group, and the aliphatic saturated hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably has 2 to 3 carbon atoms.
The saturated 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 structural unit (a4-1) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^f3 is replaced by a hydrogen atom can also be given as a specific example of the structural unit (a4-1).

Examples of the structural unit (a4-2) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^f5 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a4-2).

Examples of the structural unit (a4-3) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^f7 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a4-3).

The structural unit (a4-1) is derived from a compound represented by the formula (a4′-1) (hereinafter sometimes referred to as “compound (a4′-1)”).
[In formula (a4′-1), R ^f3 , R ^f4 and L ^{3 ′} represent the same meaning as described above. ]

Compound (a4′-1) is, for example, a compound represented by formula (a4′-1-1) and a compound represented by formula (a4′-1-2) in a solvent in a basic catalyst. It can manufacture by making it react in presence of.
[Wherein, R ^f3 , R ^f4 and L ^{3 ′} represent the same meaning as described above. ]
Examples of the solvent include tetrahydrofuran. Examples of the basic catalyst include pyridine.
Examples of the compound represented by the formula (a4′-1-1) include hydroxyethyl methacrylate, and commercially available products can be used. Further, for example, those obtained by a known method of condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride etc.) and diol (HO-L ^{3 ′} -OH) are used. be able to.
As the compound represented by the formula (a4′-1-2), the corresponding carboxylic acid can be converted into an anhydride depending on the type of R ^f4 . Commercially available products include heptafluorobutyric anhydride.

The structural unit (a4-2) is derived from a compound represented by the formula (a4′-2) (hereinafter sometimes referred to as “compound (a4′-2)”).
[In formula (a4′-2), R ^f5 , R ^f6 and L ^{4 ′} represent the same meaning as described above. ]

Compound (a4′-2) is, for example, a compound represented by formula (a4′-2-1) and a compound represented by formula (a4′-2-2) in the presence of a catalyst. It can manufacture by making it react under. As the solvent, dimethylformamide or the like is used. As the catalyst, potassium carbonate, potassium iodide and the like are used.

A commercially available product can be used as the compound represented by the formula (a4′-2-1). Examples of such commercially available products include methacrylic acid.
The compound represented by the formula (a4′-2-2) is obtained by reacting, for example, a compound represented by the formula (a4′-2-3) with a compound represented by the formula (a4′-2-4). Can be manufactured. This reaction is carried out in a solvent in the presence of a base catalyst. The solvent used in this reaction is tetrahydrofuran or the like. As the base catalyst, pyridine or the like is used.
[Wherein, R ^f6 and L ^{4 ′} represent the same meaning as described above. ]
As the compound represented by the formula (a4′-2-3), an appropriate compound can be used depending on the type of L ^{4 ′} .
As the compound represented by the formula (a4′-2-3), for example, a compound represented by the formula (a4′-2-2) when L ^{4 ′} is a methylene group by using chloroacetyl chloride or the like. Can be manufactured. This chloroacetyl chloride is readily available from the market.
As the compound represented by the formula (a4′-2-4), an appropriate alcohol can be used depending on the type of R ^f6 .
By using, for example, 2,2,3,3,4,4,4-heptafluoro-1-butanol as the compound represented by the formula (a4′-2-4), R ^f6 is substituted with a fluorine atom. A compound represented by the formula (a4′-2-2), which is an aliphatic hydrocarbon group thus produced, can be produced. This 2,2,3,3,4,4,4-heptafluoro-1-butanol is readily available from the market.

The structural unit (a4-3) is derived from a compound represented by the formula (a4′-3) (hereinafter sometimes referred to as “compound (a4′-3)”).
[In Formula (a4′-3), R ^f7 , L ^{5 ′} , A ^f13 , X ^f12 and A ^f14 represent the same meaning as described above. ]

The compound represented by the formula (a4′-3) reacts, for example, a compound represented by the formula (a4′-3-1) with a carboxylic acid represented by the formula (a4′-3-2). Can be obtained.
This reaction is usually performed in the presence of a solvent. As the solvent, tetrahydrofuran, toluene and the like are used. In the reaction, a known esterification catalyst (for example, an acid catalyst or a carbodiimide catalyst) may coexist.
[Wherein, R ^f7 , L ^{5 ′} , A ^f13 , X ^f12 and A ^f14 represent the same meaning as described above. ]

As the compound represented by the formula (a4′-3-1), a commercially available product may be used, or it may be produced by a known method. Examples of the known method include a method of condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride or the like) and a diol (HO-L ^{5 ′} -OH). Examples of commercially available products include hydroxyethyl methacrylate.
The carboxylic acid represented by the formula (a4′-3-2) can be produced by a known method. For example, any one of the following compounds may be used.

<Resin (A2)>
The resin (A2) includes a structural unit (a) having an acid labile group.
The resin (A2) may contain a structural unit (s) that does not have an acid labile group.

<Structural unit (a)>
The structural unit (a) contains an acid labile 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 to} R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination of these, or R ^a1 and R ^a2 are bonded to each other to form a divalent 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, and the methylene group contained in the hydrocarbon group and the divalent hydrocarbon group is It may be replaced with an oxygen atom or a sulfur atom. ]

^Examples of the alkyl group represented by R ^{a1 to} R ^a3 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 for R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include 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 an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group. A group in which an alkyl group and an alicyclic hydrocarbon group are combined preferably has 20 or less carbon atoms.

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

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

Examples of the hydrocarbon group for R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
In the case where R ^{a2 ′} and R ^{a3 ′} are combined to form a divalent hydrocarbon group, the * —C (R ^{a1 ′} ) (R ^{a2 ′} ) (OR ^{a3 ′} ) group includes the following groups (in the formula: , * Represents a bond.). The divalent hydrocarbon group preferably has 3 to 12 carbon atoms.
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.

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If 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 a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (1), a structural unit represented by the formula (a1-0) is preferably represented by the formula (a1-1). The structural unit represented by a structural unit or a formula (a1-2) is mentioned. These may be used alone or in combination of two or more. In this specification, the structural unit represented by formula (a1-0), the structural unit represented by formula (a1-1), and the structural unit represented by formula (a1-2) are each represented by structural unit (a1). -0), structural unit (a1-1) and structural unit (a1-2), a monomer for deriving structural unit (a1-0), a monomer for deriving structural unit (a1-1), and a structural unit (a1- The monomer that induces 2) may be referred to as monomer (a1-0), monomer (a1-1), and monomer (a1-2), respectively.

[In the formula (a1-0),
L ^a01 represents an oxygen atom or ^* —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a01 represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these. ]

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 represent an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond with a carbonyl group.
R ^a4 and R ^a5 represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a01 is preferably an oxygen atom or k01 is an integer of from 1 to 4 _{^{* -O- (CH 2) k01 -CO}} -O- , more preferably an oxygen atom or k01 is a 1 ^* -O - (CH _{2) k01} is a -CO-O-.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , 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 ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group ^{represented by} R ^a02 , R ^a03 and R ^a04 preferably has 8 or less carbon atoms, more preferably 6 or less.
The group combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less, combining the alkyl group and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group.

L ^a1 and L ^a2 are preferably an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— in which k1 is an integer of 1 to 4, more preferably an oxygen atom or k1 is 1. ^* —O— (CH ₂ ) _k1 —CO—O—.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group 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.
The group combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less, combining the alkyl group and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

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

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

As a monomer (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 (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclohexane-1- And 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 (A2) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (A2). It is 10-95 mol% normally with respect to a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

Examples of the structural unit (a) also include a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”).
In formula (a1-5),
R ^a11 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom.
Z ^a11 represents a single bond or * — [CH ₂ ] _{k1 ′} —CO—L ^a14 —. Here, k1 ′ represents an integer of 1 to 4. * Represents a bond with L ^a11 .
L ^a11 , L ^a12 , L ^a13 and L ^a14 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 (a1-5), R ^a11 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ^a11 is preferably an oxygen atom.
One of L ^a12 and L ^a13 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 ^a11 is preferably a single bond or * —CH ₂ —CO—O—.

The monomer that derives the structural unit (a1-5) may be referred to as a monomer (a1-5). As a monomer (a1-5), the following monomers are mentioned, for example.

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

  The structural unit (a) having an acid labile group in the resin (A2) includes the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2), and the structural unit (a1-5). 1 type or more selected from the group consisting of) is preferable, and two or more types are more preferable, a combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit (a1- 5), a combination of structural unit (a1-1) and structural unit (a1-0), a combination of structural unit (a1-2) and structural unit (a1-0), a structural unit (a1-5) and a structure Combination of unit (a1-0), structural unit (a1-0), combination of structural unit (a1-1) and structural unit (a1-2), or structural unit (a1-0), structural unit (a1-1) ) And the structural unit (a1-5) Preferably the al, combination of the combination of the structural units (a1-1) and the structural unit (a1-2) or structural units (a1-1) and the structural units, (a1-5) is particularly preferred.

<Structural unit having no acid labile group (s)>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). The monomer (s) may be any monomer that does not have an acid labile group, and examples thereof include known monomers used in this field.
The structural unit (s) is preferably a structural unit (s) having a hydroxy group or a lactone ring. Structural unit (s) having a hydroxy group (hereinafter sometimes referred to as “structural unit (a2)”) and / or structural unit (s) containing a lactone ring (hereinafter sometimes referred to as “structural unit (a3)”) If a resin having s is used for preparing a 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 of the present invention is applied to ArF excimer laser exposure (193 nm) or the like, the structural unit (a2) having an alcoholic hydroxy group is preferable as the structural unit (a2). When applied to high energy beam exposure such as KrF excimer laser exposure (248 nm), electron beam or EUV (extreme ultraviolet light), the structural unit (a2) having a phenolic hydroxy group may be used as the structural unit (a2). preferable. Moreover, the structural unit (a2) may contain one kind alone, or two or more kinds may be used in combination.

When the resin (A2) has a structural unit (a2), the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group.
As the structural unit (a2) having an alcoholic hydroxy group, a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”) is preferable.
In formula (a2-1),
L ^a3 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 ^a3 is preferably an oxygen _{atom, -O- (CH 2) f1 -CO} -O- and is (wherein f1 is an integer from 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.

Examples of the monomer that derives the structural unit (a2-1) include monomers described in JP 2010-204646 A. 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 (A2) contains structural unit (a2-1), the content rate is 1-45 mol% normally with respect to all the structural units of resin (A2), Preferably it is 1-40 mol%. More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Structural unit (a3)>
The lactone ring 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) or the formula (a3-3) (hereinafter referred to as “structural unit (a3- 1) "or the like). These 1 type may be contained independently and 2 or more types may be contained.

[In the formula (a3-1),
L ^a4 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 ^a5 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 ^a6 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 the formula (a3-1) to the formula (a3-3), L ^{a4 to} L ^a6 are preferably each independently an oxygen atom or k—3 is an integer of 1 to 4 * —O— (CH ₂ ) 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 are preferably methyl groups.
R ^a22 and R ^a23 are 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.

  Examples of the monomer that leads to the structural unit (a3) include monomers described in JP 2010-204646 A. Formula (a3-1-1) to Formula (a3-1-4), Formula (a3-2-1) to Formula (a3-2-4), and Formula (a3-3-1) to Formula (a3-3) -4) is preferred, and the monomers represented by formula (a3-1-1) to formula (a3-1-2) and formula (a3-2-3) to formula (a3-2-4) are preferred. The monomer represented by either is more preferable, and the monomer represented by the formula (a3-1-1) or the formula (a3-2-3) is more preferable.

When the resin (A2) includes the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A2). More preferably, it is 15-60 mol%.
In addition, the content of the structural unit (a3-1), the structural unit (a3-2), and the structural unit (a3-3) is 5 to 60 mol% with respect to all the structural units of the resin (A2), respectively. Preferably, 5-50 mol% is more preferable, and 10-50 mol% is further more preferable.

The resin (A2) is preferably a resin composed of the structural unit (a) and the structural unit (s). In this case, these content rates are respectively based on all structural units of the resin (A2).
Structural unit (a); 10-95 mol%
Structural unit (s); 5-90 mol%
Is preferred,
Structural unit (a); 15-90 mol%
Structural unit (s); 10-85 mol%
Is more preferred,
Structural unit (a); 20 to 85 mol%
Structural unit (s); 15-80 mol%
Is more preferable.

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

Each structural unit constituting the resin (A2) can be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using monomers that lead to these structural units. it can. The content rate of each structural unit which resin (A2) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (A2) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less).

  In the resist composition of the present invention, in the resin (A), the resin (A1) and the resin (A2) are, for example, resin (A1): resin (A2) = 0.01: 10 to 5:10, preferably 0. .05: 10 to 3:10, more preferably 0.1: 10 to 2:10, and still more preferably 0.2: 10 to 1:10 (mass ratio).

<Resin other than resin (A1) and (A2)>
The resist composition of the present invention may contain a resin other than the above-described resins (A1) and (A2), for example, a resin consisting only of the structural unit (s).

  In the resist composition of the present invention, the content of the resin (A) is preferably 80% by mass or more and 99% by mass or less in the solid content of the resist composition. 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.

<Acid generator (B)>
The acid generator (B) contained in the resist composition of the present invention contains an acid generator represented by the formula (II) (hereinafter sometimes referred to as “acid generator (II)”).
The acid generator (B) preferably further contains an acid generator other than the acid generator (II).

<Acid generator (II)>
The acid generator (II) is represented by the formula (II).
[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹¹ represents * —CO—O—L ^a — or * —CH ₂ —O—L ^b —. * Represents a bond with -C (Q ¹ ) (Q ² )-.
L ^a represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, a methylene group contained in the saturated hydrocarbon group of the divalent may be replaced by an oxygen atom or a carbonyl group.
L ^b represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms, and the methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ represents a heterocyclic ring having 2 to 36 carbon atoms.
Z1 ⁺ represents an organic cation. ]

In the formula (II), examples of the perfluoroalkyl group of Q ¹ and Q ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert- Examples thereof include a butyl group, a perfluoropentyl group, and a perfluorohexyl group.
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 of L ^a and L ^b constituting L ¹¹ include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated carbon group. A hydrogen group may be mentioned, and two or more of these groups may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , 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, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl 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, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl A branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

L methylene group in the divalent saturated hydrocarbon group ^a is when replaced by an oxygen atom or a carbonyl group * -CO-O-L ^a - as, for example, formula (L11-2) are preferred. * Represents a bond with C (Q ¹ ) (Q ² ) −.

Here, L ^c and L ^d each independently represent a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^c and L ^d is 15.

As * —CH ₂ —O—L ^b — when the methylene group in the divalent saturated hydrocarbon group of L ^b is replaced with an oxygen atom or a carbonyl group, for example, formula (L11-4) is preferable.

Here, ^{L e} represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.

Examples of the divalent group represented by * —CO—O—L ^a — include the following.
In the following formula, the right and left sides are described in accordance with the formula (II), and among the bonds represented by *, the bonds on the left side are combined with C (Q ¹ ) (Q ² )-and the right side is Bonds with a nitrogen atom (the same applies hereinafter).

Examples of the divalent group represented by the formula (L11-2) include the following.

Examples of the divalent group represented by * —CH ₂ —O—L ^b — include the following.

Examples of the divalent group represented by the formula (L11-4) include the following.

The heterocyclic ring of the ring W ^{1 only} needs to contain one nitrogen atom, and may further contain one or more oxygen atoms. Moreover, it may be an aromatic heterocyclic ring, may not have aromaticity, and may be monocyclic or polycyclic.
The following groups containing heterocycles
Examples of the group include the following groups. Especially, group represented by Formula (W1), Formula (W2), or Formula (W3) is preferable.

Examples of the acid generator (II) include the following salts. In the following formula, Z1 ⁺ is as defined above.

Examples of the organic cation (Z1 ⁺ ) contained in the acid generator (II) 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. Preferably, it is an organic sulfonium cation or an organic iodonium cation, and more preferably, the formula (b2-1), the formula (b2-2), the formula (b2-3), the formula (b2-4), and the formula (b2-1). -1) is an organic cation represented by any one of the above.

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represents an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, or R ^b4 And R ^b5 together form a ring containing a sulfur atom. The hydrogen atom contained in the alkyl group is substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, the plurality of R ^b7 are the same or different from each other, and when n2 is 2 or more, the plurality of R ^b8 are the same or different from each other.

R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or R ^b9 and R ^b10 are A ring is formed with the sulfur atom to be bonded.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alkyl group 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. Alternatively, it may be substituted with an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 together form a ring containing —CH—CO— to which they are attached.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are the same or different from each other. When p2 is 2 or more, the plurality of R ^b14 are the same or different from each other. When q2 is 2 or more, the plurality of R ^b15 are the same. Alternatively, when r2 is 2 or more, a plurality of R ^b16 are the same or different from each other, when s2 is 2 or more, a plurality of R ^b17 are the same or different from each other, and when t2 is 2 or more, a plurality of R ^{b16 b18} are the same or different from each other.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Can be mentioned. In particular, the alkyl group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
Examples of the alkyl group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group. 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 ^{b9 to} R ^b11 preferably has 4 to 12 carbon atoms.

  Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. Can be mentioned.

Examples of the aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-adamantyl group. Substituted or unsubstituted phenyl groups such as phenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group; biphenylyl group, naphthyl group, phenanthryl group and the like.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the alkyl group in which a hydrogen atom is 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.
In addition, when an alkyl group or an alicyclic hydrocarbon group is contained in an aromatic hydrocarbon group, a C1-C12 alkyl group and a C3-C18 alicyclic hydrocarbon group are preferable.

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

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. As long as it contains one or more sulfur atoms, it may further contain one or more oxygen atoms. That is, it may contain -O-, -S-, or -CO-. 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. Moreover, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, and preferably a 3-membered ring to a 7-membered ring.
The ring containing a sulfur atom formed by R ^b9 and R ^b10 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. As long as it contains one or more sulfur atoms, it may further contain one or more oxygen atoms, that is, —O—, —S—, and —CO—. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.
The ring containing —CH—CO— formed by R ^b11 and R ^b12 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. If it contains —CH—CO—, it may contain one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, —CO—. Good. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.

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.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the arylsulfonium cation is more preferable, and the formula (b2-1-1) is more preferable. (Hereinafter sometimes referred to as “cation (b2-1-1)”), particularly preferably triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (in formula (b2-1-1), v2 = w2 = 0, x2 = 1, R ^b21 is a methyl group) or tritylsulfonium cation (formula (b2-1-1- 1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl 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. Although 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 from each other. When w2 is 2 or more, the plurality of R ^b20 are the same or different from each other. 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.

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

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

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

  Furthermore, as the cation represented by formula (b2-1) to formula (b2-4) and formula (b2-1-1), specifically, cations described in JP 2010-204646 A are exemplified. Can be mentioned.

The acid generator (II) is a salt obtained by combining the above sulfonic acid anion and the above organic cation, and these can be arbitrarily combined.
Specific examples of the acid generator (II) are shown in the following table. In the following table, a salt represented by the formula (b1-s-1) is represented as “(b1-s-1)” according to the formula number, and the formula (b2-c-1) ) And the like are represented as “(b2-c-1)” or the like according to the formula number.

Preferred examples of the acid generator (II) include the following.

The acid generator (II) can be produced by a method known in the art or a method analogous thereto, for example, the methods shown in (a) to (c).
(A) the acid generator (II), for example, L ¹¹ is * -CO-O-L ^a - ^{[* -C (Q 1) (Q} 2) is - represents a bond to, L ^a is Represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. The salt represented by the formula (IIa) can be obtained by reacting the compound represented by the formula (IIb) with the salt represented by the formula (IIc) in the presence of a catalyst. In addition, the definition of the substituent in the following formula | equation has the same meaning as the above unless there is particular notice.
Examples of the solvent used include chloroform. Examples of the catalyst include lithium amide.
Examples of the compound represented by the formula (IIb) include 4- (8-hydroxyoctyl) morpholine, 4- (2-hydroxyethyl) morpholine, and the like.
The salt represented by the formula (IIc) can be synthesized, for example, by the method described in JP2008-13551A.

(B) Among the acid generators (II), for example, in the formula (IIa ′), L ¹¹ is * —CO—O—L ^a — and L ^a is a divalent alicyclic hydrocarbon group. The salt represented can be obtained by reacting the compound represented by the formula (IIb ′) and the salt represented by the formula (IIc ′) under a catalyst. Examples of the solvent used include chloroform.
[Wherein ring W ² represents an alicyclic hydrocarbon ring divalent alicyclic hydrocarbon group of L ^a. ]

The compound represented by the formula (IIb ′) can be obtained by reacting the compound represented by the formula (IId ′) with the compound represented by the formula (IIe ′).
Examples of the compound represented by the formula (IId ′) include morpholine.
Examples of the compound represented by the formula (IIe ′) include 1,2-epoxycyclohexane.

The compound represented by the formula (IIc ′) can be obtained by reacting the salt represented by the formula (IIf ′) with the compound represented by the formula (IIg ′).
The salt represented by the formula (IIf ′) can be synthesized, for example, by the method described in JP-A-2008-13551.

Among (c) the acid generator (II), Z1 ⁺ is an organic cation represented by the formula (b2-c-14), L 11 is * -CO-O-L ^a - a is the formula (II The salt represented by -b1) can be produced by the following method.

The salt represented by the formula (b2-c-14 ′) that induces the organic cation represented by the formula (b2-c-14) includes the compound represented by the formula (b1-a), the formula (b1-c-14 ′) The compound represented by b) can be obtained by reacting with a hydrochloric acid after reacting in a solvent in the presence of trimethylsilyl chloride. Examples of the solvent include tetrahydrofuran and the like.

The compound represented by the formula (A-b1) for inducing the sulfonate anion comprises the compound represented by the formula (b1-c) and the compound represented by the formula (b1-d) in the presence of an acid catalyst. Then, it can be obtained by reacting in a solvent.
The compound represented by the formula (b1-c) can be obtained, for example, by the method described in JP 2006-257078 A.
Examples of the compound represented by the formula (b1-d) that can be easily obtained from the market include 4- (8-hydroxyoctyl) morpholine and 4- (2-hydroxyethyl) morpholine.

  The solvent used for the reaction between the compound represented by the formula (b1-c) and the compound represented by the formula (b1-d) is n-heptane. As the acid catalyst, trifluoroacetic acid or the like is used.

By reacting the salt represented by the formula (b2-c-14 ′) obtained as described above with the compound represented by the formula (A-b1), the salt is represented by the formula (II-b1). Can be produced.
This reaction is carried out in a solvent in the presence of an acid catalyst. The solvent is chloroform or the like, and hydrochloric acid or the like is used as the acid catalyst.

  The acid generator (II) may be used alone or in combination of two or more.

<Acid generator other than acid generator (II)>
The resist composition of the present invention may contain an acid generator other than the acid generator (II) described above (hereinafter sometimes referred to as “other acid generators”).
Other acid generators may be either nonionic or ionic. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

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

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

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

Examples of the divalent saturated hydrocarbon group for L ^b1 include a divalent aliphatic saturated hydrocarbon group such as a linear alkanediyl group or a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic ring. Formula saturated hydrocarbon group etc. are mentioned, What combined 2 or more types among these groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , 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, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Branched alkanediyl groups such as diyl groups;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which the methylene group contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by an oxygen atom or a carbonyl group are represented by any of formulas (b1-1) to (b1-7). Groups. The formula (b1-1) to the formula (b1-7) are described in accordance with the formula (B1) on the left and right sides, and C (Q ^b1 ) on the left side of two bonds represented by *, respectively. Bonded with (Q ^b2 )-and on the right side with -Y. The same applies to specific examples of the following formulas (b1-1) to (b1-7).

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^{b2 ′} represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^{b4 ′} represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom. However, the upper limit of the total carbon number of L ^b3 , L ^b4 and L ^{b4 ′} is 14.
L ^b5 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b6 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom. 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 aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a C 1-16 divalent aliphatic saturated hydrocarbon group, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom. 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 aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b10 represents a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^{b10 ′} represents a single bond or a C 1-13 divalent aliphatic saturated hydrocarbon group, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom. However, the upper limit of the total carbon number of L ^b9 , L ^b10 and L ^{b10 ′} is 14.
L ^b11 and L ^b12 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b13 represents a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^{b13 ′} represents a single bond or a C 1-11 divalent aliphatic saturated hydrocarbon group, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom. However, the upper limit of the total carbon number of L ^b11 , L ^b12 , L ^b13 and L ^{b13 ′} is 12.
L ^b14 and L ^b15 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b16 represents a C 1-14 divalent aliphatic saturated hydrocarbon group, and the hydrogen atom contained in the aliphatic saturated hydrocarbon group may be substituted with a fluorine atom. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 14.

L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably a group represented by formula (b1-1) or formula (b1-2). Can be mentioned.

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

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

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

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

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

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

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

Examples of the substituent that the divalent saturated hydrocarbon group of L ^b1 may have include a halogen atom (preferably a fluorine atom), a hydroxy group, and the like. Examples of the group in which a hydrogen atom is substituted with a fluorine atom or a hydroxy group include the following divalent groups.

Examples of the alkyl group for Y include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, 2 -Alkyl groups, such as an ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, are mentioned, Preferably, a C1-C6 alkyl group is mentioned.
Examples of the alicyclic hydrocarbon group include groups represented by formulas (Y1) to (Y11).
Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group of Y is replaced with an oxygen atom, a sulfonyl group, or a carbonyl group include groups represented by formulas (Y12) to (Y26).

  Especially, as an alicyclic hydrocarbon group of Y, Preferably it is group represented by either of Formula (Y1)-Formula (Y19), More preferably, Formula (Y11), Formula (Y14), Formula It is a group represented by (Y15) or formula (Y19), more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent for the alkyl group in Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aromatic hydrocarbon having 6 to 18 carbon atoms. Group, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, 3 to 3 carbon atoms, 16 represents an alicyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4).
Examples of the substituent for the alicyclic hydrocarbon group in 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 ) _{j 2} —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) Represents a group hydrocarbon group, j2 represents an integer of 0 to 4, and the like.
The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are the substituents, may further have a substituent. Examples of the substituent here include an alkyl group, a halogen atom, and a hydroxy group.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
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 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. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

In the case where Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y. The methylene group of the 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 5 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent. The methylene group contained may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. Y is more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

The sulfonate anion in the acid generator (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulas, the definitions of the symbols 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).
Specific examples of the sulfonate anion in the acid generator (B1) include anions described in JP 2010-204646 A.

Examples of the organic cation (Zb ⁺ ) contained in the acid generator (B1) include organic onium cations such as organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. Is an organic sulfonium cation or an organic iodonium cation, more preferably an arylsulfonium cation, and still more preferably a cation represented by any one of the formulas (b2-1) to (b2-4) described above. It is the same thing.

  As an acid generator (B1), what is represented by either of Formula (B1-1)-Formula (B1-24) is mentioned, for example. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-5), Formula (B1-6), Formula (B1-7) ), Formula (B1-11), formula (B1-12), formula (B1-13), formula (B1-14), formula (B1-13), formula (B1-20), formula (B1-21) And a salt represented by any of formula (B1-22) is more preferred.

The content of the acid generator (II) is preferably 0.1 parts by mass or more and more preferably 0.3 parts by mass or more with respect to 100 parts by mass of the resin (A). Moreover, Preferably it is 10 mass parts or less, More preferably, it is 3 mass parts or less.
When the resist composition of the present invention contains another acid generator, the content ratio of the acid generator (II) to the other acid generator (preferably the acid generator (B1)) is based on mass, for example, 1: 599-50: 50, preferably 2: 98-40: 60, more preferably 3: 97-30: 70.
Content of an acid generator (B) becomes like this. Preferably it is 1 mass part or more with respect to 100 mass parts of resin (A), More preferably, it is 3 mass parts or more. Moreover, it is 40 mass parts or less with respect to 100 mass parts of resin (A), More preferably, it is 35 mass parts or less.

<Solvent (E)>
The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% 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 may contain individually by 1 type and may contain 2 or more types.

<Basic compound (C)>
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Amine includes aliphatic and aromatic amines, primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by any one of the formulas (C1) to (C8) and (C1-1), more preferably represented by the formula (C1-1). The compound which is made 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. 10 represents an aromatic hydrocarbon group, and 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 is 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 group having 6 to 10 carbon atoms. It may be substituted with a group hydrocarbon group. ]

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 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 ^c4 are the same or different from each other. ]

[In Formula (C2), Formula (C3) and Formula (C4), R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an acyl group having 2 to 7 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different from each other. ]

[In Formula (C5) and Formula (C6), R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, and when o3 is 2 or more, the plurality of R ^c14 are the same or different from each other, and when p3 is 2 or more, the plurality of R ^c15 are the same as each other Or different.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent 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 ^c18 are the same or different from each other, and when r3 is 2 or more, the plurality of R ^c19 are When the same or different from each other and s3 is 2 or more, the plurality of R ^c20 are the same or different from each other.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, 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 acyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, 2,2-dimethylpropionyl group, and benzoyl 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 resist composition of the present invention contains a basic compound (C), the content thereof is preferably about 0.01 to 5% by mass, more preferably 0, based on the solid content of the resist composition. About 0.01 to 3% by mass, particularly preferably about 0.01 to 1% by 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 is prepared by mixing the resin (A) and the acid generator (B), and the solvent (E), basic compound (C) and other components (F) used as necessary. Can do. 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. By adjusting the conditions of the coating apparatus, the film thickness of the composition after coating can be adjusted. Examples of the substrate include a silicon wafer. This substrate may be washed before applying the resist composition, or an antireflection film may be formed using a commercially available organic antireflection film composition.

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 types of laser light such as those that convert the wavelength of laser light from the laser to emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams, extreme ultraviolet light (EUV), etc. it can. 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. 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 acid labile group of the resin (A). As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.

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

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 exposure, or a resist composition for EUV exposure, particularly for immersion exposure. It is suitable as a resist composition and is useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The 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 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 salt represented by formula (II-161)]
50 parts of the compound represented by the formula (II-161-a) and 250 parts of tetrahydrofuran were charged into a reactor, stirred at 30 ° C. for 30 minutes, and 50.23 parts of trimethylsilyl chloride was added dropwise. The obtained mixed liquid was cooled to 0 ° C., and 157.20 parts of a compound represented by the formula (II-161-b) (purity: 32%, manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over 30 minutes, and further to 23 ° C. The temperature was raised, and the mixture was stirred at the same temperature for 1 hour. To the resulting reaction mixture, 125 parts of 1N hydrochloric acid was charged, stirred and allowed to stand, and separated to recover the aqueous layer. To the recovered aqueous layer, 125 parts of tert-butyl methyl ether was added, stirred and allowed to stand, and the aqueous layer was recovered by liquid separation. To the recovered aqueous layer, 125 parts of chloroform was added, stirred and allowed to stand, and separated to recover the organic layer. The collected organic layer was filtered, and the obtained filtrate was concentrated. The concentrated residue was charged with 28.33 parts of acetonitrile and 354.15 parts of tert-butyl methyl ether, stirred at 23 ° C. for 30 minutes, and the precipitated crystals were filtered, thereby being represented by the formula (II-161-c). Compound 53.00 parts was obtained.

Moreover, the compound represented by the formula (II-161-d) was synthesized by the method described in JP-A-2006-257078.
16.80 parts of the compound represented by the formula (II-161-d), 18.30 parts of the compound represented by the formula (II-161-e) and 250 parts of n-heptane were charged into the reactor, and 30 Stir at 30 ° C. for 30 minutes. Thereafter, 12.80 parts of trifluoroacetic acid was added thereto, the temperature was raised, and reflux dehydration was performed at 100 ° C. for 20 hours. The obtained reaction mixture was cooled to about 80 ° C., and 250 parts of acetonitrile was added at the same temperature. Furthermore, concentration was performed, and 290 parts of ethyl acetate was added to the obtained concentrated residue, followed by stirring at 23 ° C. for 30 minutes. The precipitated crystals were filtered to obtain 21.11 parts of a compound represented by the formula (II-161-f).

26.18 parts of a compound represented by the formula (II-161-f) and 147.39 parts of chloroform were charged into a reactor, stirred at 30 ° C. for 30 minutes, and represented by the formula (II-161-c). 200.71 parts of salt and 62.27 parts of ion-exchanged water were added. Subsequently, 6.90 parts of 35% hydrochloric acid was added dropwise and stirred at 23 ° C. for 12 hours. To the resulting reaction mixture, 12.00 parts of 28% aqueous ammonia was added dropwise and separated to recover the organic layer. The recovered organic layer was charged with 49.13 parts of ion-exchanged water and stirred, allowed to stand, and washed with water for liquid separation five times. The obtained organic layer was charged with 2.05 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10.97 parts of acetonitrile and 137.06 parts of tert-butyl methyl ether were added to the resulting concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 25.50 parts of the salt represented by the formula (II-161).
MASS (ESI (+) Spectrum): M ⁺ 277.1
MASS (ESI (−) Spectrum): M ^- 372.1

Synthesis Example 2: Synthesis of salt represented by formula (II-5)
A salt represented by the formula (II-5-b) was synthesized by the method described in JP-A-2008-13551.
10 parts of a compound represented by the formula (II-5-b), 60 parts of chloroform, 5.71 parts of a compound represented by the formula (II-5-a), molecular sieve (trade name: Molecular sieve 5A Wako Pure Chemical Industries, Ltd.) (Product) 14.00 parts and 0.33 parts of lithium amide were charged, heated to reflux at 80 ° C. for 24 hours, and filtered. The obtained filtrate was charged with 15 parts of a 3.6% oxalic acid aqueous solution, and stirred and separated. To the obtained organic layer, 15 parts of ion-exchanged water was added, and the mixture was stirred and separated. Water washing was performed 6 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 100 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained residue, 200 parts of tert-butyl methyl ether was added and stirred, stirred for 30 minutes, and filtered to obtain 6.64 parts of the salt represented by the formula (II-5).
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (−) Spectrum): M ⁻ 372.1

Synthesis Example 3: Synthesis of salt represented by formula (II-6)
A salt represented by the formula (II-5-b) was synthesized by the method described in JP-A-2008-13551.
10 parts of a compound represented by the formula (II-5-b), 60 parts of chloroform, 7.20 parts of a compound represented by the formula (II-6-a), molecular sieve (trade name: Molecular sieve 5A Wako Pure Chemical Industries, Ltd.) (Product) 14.00 parts and 0.33 parts of lithium amide were charged, heated to reflux at 80 ° C. for 24 hours, and filtered. The obtained filtrate was charged with 15 parts of a 3.6% oxalic acid aqueous solution, and stirred and separated. To the obtained organic layer, 15 parts of ion-exchanged water was added, and the mixture was stirred and separated. Water washing was performed 6 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 100 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained residue, 200 parts of tert-butyl methyl ether was added, stirred, stirred for 30 minutes, and filtered to obtain 6.81 parts of the salt represented by the formula (II-6).
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 428.2

Synthesis Example 4: Synthesis of salt represented by formula (II-11)
Charge 46.60 parts of the compound represented by the formula (II-11-a), 27.54 parts of ion-exchanged water and 50 parts of the compound represented by the formula (II-11-b), and heat at 105 ° C. for 2 hours. After refluxing, it was cooled to 23 ° C. To the obtained reaction solution, 450 parts of a saturated aqueous sodium hydroxide solution and 400 parts of tert-butyl methyl ether were added, and the mixture was stirred and separated. To the obtained organic layer, 5.00 parts of magnesium sulfate was charged, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was distilled under reduced pressure, and a liquid having a boiling point in the range of 104 to 107 ° C./2 to 3 mmHg was fractionated to obtain 62.69 parts of a compound represented by the formula (II-11-c).

A salt represented by the formula (II-11-d) was synthesized by the method described in JP 2008-127367 A.
First, 10 parts of the salt represented by the formula (II-11-d) and 60 parts of acetonitrile were charged, stirred at 40 ° C. for 30 minutes, and then charged with 4.34 parts of the compound represented by the formula (II-11-e). And stirred at 50 ° C. for 2 hours. The obtained reaction product was cooled to 23 ° C. and filtered to obtain a solution containing a compound represented by the formula (II-11-f). 3.78 parts of a compound represented by the formula (II-11-c) and 7.57 parts of chloroform were charged and stirred at 23 ° C. for 1 hour. Then, the solution containing the compound represented by the formula (II-11-f) obtained earlier was charged and stirred at 23 ° C. for 1 hour. The resulting reaction was concentrated. The concentrate was charged with 60 parts of chloroform and 30 parts of ion-exchanged water, and stirred and separated. Water washing was performed 6 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 100 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained residue, 200 parts of tert-butyl methyl ether was added and stirred, stirred for 30 minutes, and filtered to obtain 6.03 parts of the salt represented by the formula (II-11).

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (−) Spectrum): M ⁻ 342.1

Synthesis Example 5: Synthesis of salt represented by formula (II-180)
46.60 parts of the compound represented by the formula (II-180-a), 27.54 parts of ion-exchanged water and 50.00 parts of the compound represented by the formula (II-180-b) were charged, and the mixture was charged with 2 After heating at reflux for an hour, it was cooled to 23 ° C. To the obtained reaction solution, 450 parts of a saturated aqueous sodium hydroxide solution and 400 parts of tert-butyl methyl ether were added, and the mixture was stirred and separated. To the obtained organic layer, 5.00 parts of magnesium sulfate was charged, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was distilled under reduced pressure, and a liquid having a boiling point of 104 to 107 ° C./2 to 3 mmHg was fractionally distilled to obtain 62.69 parts of a compound represented by the formula (II-180-c).

16.80 parts of the compound represented by the formula (II-180-d), 15.75 parts of the compound represented by the formula (II-180-c) and 250 parts of tert-butyl methyl ether were charged into the reactor. After stirring at 30 ° C. for 30 minutes, 12.80 parts of trifluoroacetic acid was added, the temperature was raised, and the mixture was reflux dehydrated at 100 ° C. for 20 hours. The obtained reaction mixture was cooled to about 80 ° C., and 250 parts of acetonitrile was added at the same temperature. Furthermore, it concentrated and obtained the residue containing the compound represented by a formula (II-180-f).

The residue containing the compound represented by the formula (II-180-f) obtained above was charged with 75 parts of chloroform, stirred at 30 ° C. for 30 minutes, and then represented by the formula (II-180-e). 10.36 parts of salt and 31.07 parts of ion exchange water were added. Subsequently, 3.45 parts of 35% hydrochloric acid was added dropwise, followed by stirring at 23 ° C. for 12 hours. To the resulting reaction mixture, 6.00 parts of 28% ammonia water was added dropwise, followed by liquid separation to recover the organic layer. To the collected organic layer, 25 parts of ion-exchanged water was charged, and water washing operations such as stirring, standing and liquid separation were performed 5 times in total. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 100 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained residue, 200 parts of tert-butyl methyl ether was added and stirred, stirred for 30 minutes, and filtered to obtain 9.83 parts of the salt represented by the formula (II-180).
MASS (ESI (+) Spectrum): M ⁺ 277.1
MASS (ESI (−) Spectrum): M ⁻ 342.1

Synthesis Example 6: Synthesis of salt represented by formula (B1-5)
50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, 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, and 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 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 filtered to obtain 61.54 parts of the salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

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

Synthesis Example 7 [Synthesis of Resin A1-1]
As the monomer, monomer (I′-1) and monomer (a4′-0-1) were used, and the molar ratio (monomer (I′-1): monomer (a4′-0-1)) was 50:50. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 4 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total monomer amount, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of methanol / water mixed solvent to precipitate a resin, and this resin is filtered to obtain a resin A1-1 (copolymer) having a weight average molecular weight of 1.1 × 10 ^4. Obtained at 89%. This resin A1-1 has the following structural units.

Synthesis Example 8 [Synthesis of Resin A1-2]
As the monomer, monomer (I′-2) and monomer (a4′-0-1) were used, and the molar ratio (monomer (I′-2): monomer (a4′-0-1)) was 50:50. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 4 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total monomer amount, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin A1-2 (copolymer) having a weight average molecular weight of 1.2 × 10 ^{4 in} a yield. Obtained at 92%. This resin A1-2 has the following structural units.

Synthesis Example 9 [Synthesis of Resin A1-3]
As the monomer, monomer (I′-1) and monomer (a4′-0-1) were used, and the molar ratio (monomer (I′-1): monomer (a4′-0-1)) was 75:25. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 4 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total monomer amount, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of methanol / water mixed solvent to precipitate a resin, and this resin is filtered to obtain a resin A1-3 (copolymer) having a weight average molecular weight of 9.8 × 10 ^3. Obtained at 87%. This resin A1-3 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1-4]
As the monomer, monomer (I′-1) and monomer (a4′-0-1) were used, and the molar ratio (monomer (I′-1): monomer (a4′-0-1)) was 25:75. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 4 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total monomer amount, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a methanol / water mixed solvent to precipitate a resin, and this resin is filtered to obtain a resin A1-4 (copolymer) having a weight average molecular weight of 1.3 × 10 ^4. Obtained at 90%. This resin A1-4 has the following structural units.

Synthesis Example 11 [Synthesis of Resin A1-5]
As the monomer, monomer (I′-1) and monomer (a4′-0-12) were used, and the molar ratio [monomer (I′-1): monomer (a4′-0-12)] was 50:50. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 3 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added based on the total amount of monomers, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin A1-5 (copolymer) having a weight average molecular weight of 1.0 × 10 ^4. Obtained at 91%. This resin A1-5 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-6]
As the monomer, monomer (I′-1) and monomer (a4′-0-16) were used, and the molar ratio [monomer (I′-1): monomer (a4′-0-16)] was 50:50. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 4.5 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total monomer amount, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin A1-6 (copolymer) having a weight average molecular weight of 1.2 × 10 ^4. Obtained at 98%. This resin A1-6 has the following structural units.

Synthesis Example 13 [Synthesis of Resin A2-1]
As the monomer, using monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (a3-1-1)] It mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and this resin was filtered to obtain a resin A2-1 having a weight average molecular weight of 7.8 × 10 ³ . (Copolymer) was obtained with a yield of 73%. This resin A2-1 had the following structural units and was soluble in butyl acetate.

Synthesis Example 14: [Synthesis of Resin A2-2]
As the monomer, monomer (a1-1-1), monomer (a3-1-1) and monomer (a2-1-1) were used, and the molar ratio (monomer (a1-1-1): monomer (a3-1) -1): The monomer (a2-1-1)) was mixed to be 35:45:20, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. A 10 ³ resin A2-2 was obtained with a yield of 75%. This resin A2-2 has the following structural units.

Synthesis Example 15 [Synthesis of Resin A2-3]
As the monomer, using monomer (a1-1-3), monomer (a1-5-1), monomer (a2-1-3), monomer (a3-2-1) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-5-1): monomer (a2-1-3): monomer (a3-2-1): monomer (a3-1-1)] 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 6 × 10 ³ resin A2 was obtained with a yield of 68%. This resin A2 has the following structural units.

Synthesis Example 16 [Synthesis of Resin A2-4]
As the monomer, using monomer (a1-1-3), monomer (a1-0-9), monomer (a2-1-3), monomer (a3-2-1) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-0-9): monomer (a2-1-3): monomer (a3-2-1): monomer (a3-1-1)] 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° 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 obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 6 × 10 ³ resin A2-4 was obtained with a yield of 70%. This resin A2-4 has the following structural units.

Synthesis Example 17 [Synthesis of Resin A2-5]
As the monomer, using monomer (a1-0-10), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-0-10): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (a3-1-1)] 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.6 mol% and 4.8 mol%, respectively, with respect to the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 7 × 10 ³ resin A2-5 was obtained with a yield of 80%. This resin A2-5 has the following structural units.

Synthesis Example 18 [Synthesis of Resin A2-6]
As the monomer, using monomer (a1-1-3), monomer (a1-0-1), monomer (a2-1-3), monomer (a3-2-1) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-0-1): monomer (a2-1-3): monomer (a3-2-1)): monomer (a3-1-1)] However, it mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° 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 obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 6 × 10 ³ resin A2-6 was obtained with a yield of 70%. This resin A2-6 has the following structural units.

Synthesis Example 19: [Synthesis of Resin X1]
As the monomer, monomer (a4-2-3) and monomer (a1-1-1) were used, and the molar ratio (monomer (a4-2-3): monomer (a1-1-1)) was 80:20. The mixture was mixed so that 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.5 mol% and 1.5 mol%, respectively, based on the total monomer amount, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 2.8. A × 10 ⁴ resin X1 (copolymer) was obtained with a yield of 70%. This resin X1 has the following structural units.

Examples 1 to 16 and Comparative Example 1
<Preparation of resist composition>
As shown in Table 2, each component was mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1-1 to A1-6: Resins A1-1 to A1-6
A2-1 to A2-6: Resins A2-1 to A2-6
X1: Resin X1
<Acid generator>
II-161: salt represented by formula (II-161) II-5: salt represented by formula (II-5) II-6: salt represented by formula (II-6) II-11: formula Salt represented by (II-11) II-180 :: Salt represented by formula (II-180) B1-5: Salt represented by formula (B1-5) B2: Implementation of WO2008 / 99869 Example and synthesis according to the examples of JP 2010-26478 A
B3: synthesized according to the example of JP-A-2005-221721

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent (E)>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<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 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 2 for 60 seconds to form a composition layer on the silicon wafer. An ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Dipole 0.900 / 0.700 Y-pol.] Is applied to the composition layer formed on the silicon wafer. Illumination], using a mask for forming a trench pattern (pitch 120 nm / trench width 40 nm), the exposure amount was changed stepwise to perform exposure. 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 2. Next, a negative resist pattern was manufactured by developing the heated composition layer 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. .

  In the obtained resist pattern, the exposure amount at which the line width of the trench pattern was 40 nm was defined as effective sensitivity.

<Focus margin evaluation (DOF)>
A negative resist pattern was manufactured in the same manner as described above except that the exposure was performed while changing the focus stepwise in terms of effective sensitivity. In the obtained resist pattern, the focus range in which the width of the trench pattern is 40 nm ± 5% (38 to 42 nm) was defined as DOF (nm). The results are shown in Table 3.

<Defect evaluation>
ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized illumination] for forming a 1: 1 line and space pattern (pitch 80 nm) Using the mask, a negative resist pattern was manufactured by performing the same operation as above except that exposure was performed with an exposure amount at which the line width and space width of the obtained line and space pattern were 1: 1.
Thereafter, the number of defects (pieces) on the line pattern on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. The results are shown in Table 3.

  According to the resist composition of the present invention, a negative resist pattern can be produced with an excellent focus margin (DOF), and the number of occurrences of defects in the obtained resist pattern is small.

Claims (6)

A resin having a structural unit represented by formula (I) and a structural unit represented by formula (a4) and having no acid labile group,
At least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-0), a formula ( a structural unit represented by a1-1), a structural unit represented by formula (a1-2) and at least one selected from the group consisting of a structural unit represented by formula (a1-5). A resin having an acid labile group, and
A resist composition for developing with an organic solvent containing an acid generator represented by formula (II).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group or hydroxy group having 1 to 8 carbon atoms. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ¹ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ¹ represents a single bond or a C 1-18 divalent saturated hydrocarbon group, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]
[In the formula (a4),
R ³ represents a hydrogen atom or a methyl group.
R ⁴ represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]
[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹¹ represents * —CO—O—L ^a — or * —CH ₂ —O—L ^b —. * Represents a bond with -C (Q ¹ ) (Q ² )-.
L ^a represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, a methylene group contained in the saturated hydrocarbon group of the divalent may be replaced by an oxygen atom or a carbonyl group.
L ^b represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms, and the methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ represents a heterocyclic ring having 2 to 36 carbon atoms.
Z1 ⁺ represents an organic cation. ]
[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]
[In the formula (a1-0),
L ^a01 represents an oxygen atom or ^* —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a01 represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these. ]
[In the formula (a1-5),
R ^a11 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom.
Z ^a11 represents a single bond or * — [CH ₂ ] _{k1 ′} —CO—L ^a14 —. Here, k1 ′ represents an integer of 1 to 4. * Represents a bond with L ^a11 .
L ^a11 , L ^a12 , L ^a13 and L ^a14 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. ] ^2. The resist composition according to claim 1, wherein R2 in the formula (I) is an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms. The resist composition according to claim 1 or 2, wherein the structural unit represented by the formula (a4) is a structural unit represented by the formula (a4-0).
[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]   Containing the structural unit represented by the formula (I) in the resin having the structural unit represented by the formula (I) and the structural unit represented by the formula (a4) and having no acid labile group The rate is 25 to 75 with respect to all structural units of the resin having the structural unit represented by formula (I) and the structural unit represented by formula (a4) and having no acid labile group. The resist composition according to claim 1, wherein the resist composition is mol%. L ¹¹ in formula (II) is * —CO—O—L ^a — (L ^a represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms, and * represents —C (Q ¹ ) (Q ² ). -Represents a bond to-.) The resist composition according to any one of claims 1 to 4. (1) The process of apply | coating the resist composition as described in any one of Claims 1-5 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 with an organic solvent .