JP6310673B2 - 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 exposure margin (EL) at the time of producing 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. ]
R ^b1 and R ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W ^b1 represents a heterocyclic ring having 2 to 36 carbon atoms.
R ^b3 represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^b4 represents a hydrocarbon group having 1 to 6 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
m represents an integer of 0-6. When m is 2 or more, the plurality of R ^b4 are the same or different.
Z1 ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein R ² in the 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] The resist composition according to any one of [1] to [5], wherein L ^b1 in the formula (II) is a group represented by the formula (L1-1).
[In Formula (L1-1), L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. * Represents a bond with —C (R ^b1 ) (R ^b2 ) —. ]
[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 exposure margin (EL). 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)”).
The acid generator (B) includes an acid generator represented by the formula (II) (hereinafter sometimes referred to as “acid generator (II)”).
It is preferable that the resist composition of the present invention further contains a solvent (E).
Further, a basic compound (C) may be contained.

<Resin (A)>
The resin (A) contained in the resist composition of the present invention has a structural unit represented by the above formula (I) and a structural unit represented by the formula (a4), and an acid labile group A resin that does not have (hereinafter sometimes 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.
Resin (A) may contain resins other than resins (A1) and (A2).

<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 (X1-1) to (X1-4). In the following formula, * represents a bond with an oxygen atom.
In formula (X1-1),
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 (X1-2),
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 (X1-3),
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 (X1-4),
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 (X1-1), the bivalent group shown below is mentioned, for example.

As group represented by a formula (X1-2), the bivalent group shown below is mentioned, for example.

As group represented by a formula (X1-3), the bivalent group shown below is mentioned, for example.

As group represented by a formula (X1-4), the bivalent group shown below is mentioned, for example.

L ¹ is preferably a single bond or a group represented by the formula (X1-1).

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 ³ 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 60 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 can be produced with an excellent exposure margin, and in particular, a resist pattern with few defects can be produced.

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 an oxygen atom.

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) having a group represented by the formula (2) 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 each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

  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%.
Further, 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 (A). 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),
R ^b1 and R ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W ^b1 represents a heterocyclic ring having 2 to 36 carbon atoms.
R ^b3 represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^b4 represents a hydrocarbon group having 1 to 6 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
m represents an integer of 0-6. When m is 2 or more, the plurality of R ^b4 are the same or different.
Z1 ⁺ represents an organic cation. ]
In the formula (II), those having a negative charge obtained by removing the organic cation represented by Z1 ⁺ having a positive charge may be referred to as “sulfonate anion”.

Examples of the perfluoroalkyl group for R ^b1 and R ^b2 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. And perfluorohexyl group.
R ^b1 and R ^b2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and among these groups, Two or more types 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, 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;
Cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1,2-diyl group, cyclohexane-1,4-diyl group, cyclo A monocyclic alicyclic saturated hydrocarbon group which is a cycloalkanediyl group such as an octane-1,2-diyl group or a cyclooctane-1,5-diyl group;
A polycyclic group such as norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. An alicyclic saturated hydrocarbon group etc. are mentioned.
The divalent alicyclic hydrocarbon group may be a group obtained by removing any one hydrogen atom from a monovalent alicyclic hydrocarbon group described later.

The heterocyclic ring of ring W ^b1 may be any ring containing one or more nitrogen atoms, and may further contain one or more nitrogen atoms, one or more oxygen atoms, one or more sulfur atoms, and the like. Good. The heterocyclic ring may be an aromatic heterocyclic ring, or may have no aromaticity, and may be a monocyclic, polycyclic, condensed ring or bridged ring. .
Examples of the heterocyclic ring include the following rings. However, the methylene group contained in these heterocyclic rings may be replaced with an oxygen atom or a carbonyl group. Among these, a ring represented by the formula (W1), a ring represented by the formula (W2), and a ring represented by the formula (W3) are preferable. * Represents a bond with L ^b1 .

Examples of the hydrocarbon group for R ^b3 and R ^b4 include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the aliphatic hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, 2,2-dimethylethyl, 1-methylpropyl, and 2-methylpropyl. Group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, n-hexyl group, 1 -Propylbutyl group, pentyl group, 1-methylpentyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl group, methyloctyl group, methylnonyl group, 2-ethylhexyl group, nonyl group, decyl And alkyl groups such as a group, an undecyl group, and a dodecyl group.

The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples thereof include monocyclic alicyclic hydrocarbon groups such as a cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group). Polycyclic such as a group in which a condensed cyclic aromatic hydrocarbon group is hydrogenated (for example, a hydronaphthyl group), a bridged cyclic hydrocarbon group (for example, an adamantyl group, a norbornyl group, or a group represented by the following formula) Of the alicyclic hydrocarbon group.
Examples of the group obtained by combining an aliphatic hydrocarbon group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
As aromatic hydrocarbon group, phenyl group, naphthyl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-adamantylphenyl group, tolyl group , Aryl groups such as xylyl group, cumenyl group, mesityl group, biphenyl group, anthryl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.

In the acid generator (II), R ^b1 and R ^b2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the group in which the methylene group in the saturated hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group include formula (L1-1) to formula (L1-6). Formulas (L1-1) to (L1-6) are described in accordance with Formula (I) on the left and right, and C (R ^b1 ) on the left side of two bonds represented by * Bonded to (R ^b2 ) — and on the right side to ring W ^b1 . The same applies to specific examples of the following formulas (L1-1) to (L1-6).

In formula (L1-1) to formula (L1-6),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.

Among them, L ^b1 is preferably any one of formula (L1-1) to formula (L1-4), more preferably formula (L1-1) or formula (L1-2), and still more preferably formula (L1). -1) is a divalent group. Particularly preferably, L ^b2 is a single bond or a saturated hydrocarbon group having 1 to 6 carbon atoms, that is, * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents −. A divalent group represented by the formula (b1-1), wherein L ^b2 is a single bond or a methylene group, and particularly preferably represents a bond to C (R ^b1 ) (R ^b2 ) —. Even more preferably, L ^b2 is a divalent group represented by the formula (b1-1) in which it is a single bond, that is, * —CO—O—.

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

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

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

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

Examples of the divalent group represented by the formula (L1-5) include the following.

Examples of the divalent group represented by the formula (L1-6) include the following.

R ^b3 is preferably a hydrogen atom, a methyl group, an ethyl group or a tert-butoxycarbonyl group, and more preferably a hydrogen atom, a methyl group or a tert-butoxycarbonyl group.
m is preferably 0, but when m is an integer of 1 to 6, R ^b4 is preferably a methyl group, an ethyl group, a methylcarbonyloxy group (acetyloxy group), an ethylcarbonyloxy group or the like. Can be mentioned.

Examples of the acid generator (II) include the following compounds.

Examples of Z1 ⁺ include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.

Examples of preferable cations include cations represented by formulas (Z1) to (Z4).

In formula (Z1) to formula (Z4),
Do P ^{a to} P ^c each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms? , P ^a and P ^b together form a ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.

P ⁴ and P ⁵ each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
P ⁶ and P ⁷ each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or P ⁶ and P ^{7 taken} together P ⁸ which forms a ring containing a sulfur atom to which is bonded is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic having 6 to 18 carbon atoms. Represents a group hydrocarbon group.
P ⁹ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon 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 has 1 to 12 carbon atoms. It may be substituted with an alkoxy group or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
P ⁸ and P ⁹ together form a ring containing —CH—CO— to which they are attached.

P ¹⁰ to P ¹⁵ each independently represent a hydroxy group, an aliphatic hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
E represents a sulfur atom or an oxygen atom.
i, j, p, r, x and y each independently represents an integer of 0 to 5;
q represents 0 or 1;
v and w each independently represent an integer of 0 to 4.
When i is 2 or more, the plurality of P ⁴ are the same or different from each other, when j is 2 or more, the plurality of P ⁵ are the same or different from each other, and when p is 2 or more, the plurality of P ¹⁰ are When r is 2 or more, the plurality of P ¹¹ are the same or different, and when v is 2 or more, the plurality of P ¹² are the same or different and when w is 2 or more, P ¹³ is the same or different from each other. When x is 2 or more, the plurality of P ¹⁴ are the same or different from each other. When y is 2 or more, the plurality of P ¹⁵ are the same or different from each other.

Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned. In particular, the P ^{6 to} P ⁹ aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
The alicyclic hydrocarbon group 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. And cycloalkyl groups such as cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
In particular, the P ^{6 to} P ⁹ alicyclic hydrocarbon group preferably has 3 to 36 carbon atoms, more preferably 3 to 18 carbon atoms, and still more preferably 4 to 12 carbon atoms.

Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a 2-alkyladamantan-2-yl group, and a methyl group. A norbornyl group, an isobornyl group, etc. are mentioned.
As an aromatic hydrocarbon group, phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-adamantylphenyl group And aryl groups such as tolyl group, xylyl group, cumenyl group, mesityl group, biphenylyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms Groups are preferred.

As the alkoxy group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, heptyloxy group Octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy 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 halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The ring containing a sulfur atom formed by combining P ^a and P ^b 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. Examples of the ring include a ring having 3 to 18 carbon atoms, and a ring having 4 to 18 carbon atoms is 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 sulfur atoms formed by P ⁶ and P ⁷ together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. , —CH—CO— may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —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 P ⁸ and P ⁹ 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 containing a sulfur atom formed by P ⁶ and P ⁷ together include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4 -Ium ring etc. are mentioned.
Examples of the ring containing —CH—CO— formed by P ⁸ and P ⁹ together include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cations represented by the formulas (Z1) to (Z4), the formula (Z1) is preferable, the arylsulfonium cation is more preferable, the cation represented by the formula (Z5) is more preferable, and the triphenylsulfonium cation (formula (Z5) in, z1 = z2 = z3 = 0 ), in diphenyl tolyl sulfonium cation (formula (Z5), a z1 = z2 = 0, z3 = 1, P 3 is a methyl group.) or tri tolyl sulfonium A cation (in formula (Z5), z1 = z2 = z3 = 1 and P ¹ , P ² and P ³ are all methyl groups) is particularly preferable.

In formula (Z5),
P ^{1 to} P ³ are each independently a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. Or two selected from P ^{1 to} P ³ together form a ring containing a sulfur atom.
z1, z2 and z3 each independently represents an integer of 0 to 5. When any of z1, z2 and z3 is 2 or more, the plurality of P ¹ , P ² and P ³ are the same or different from each other.

The ring formed by combining two selected from P ^{1 to} P ³ may be any of monocyclic, polycyclic, aromatic and non-aromatic rings. As long as it contains the above, it may contain one or more oxygen atoms.
The P ^{1 to} P ³ aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
Among these, P ^{1 to} P ³ each independently represent 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, or P ¹ It is preferable that two selected from P ³ together form a ring containing an oxygen atom and a sulfur atom. Each z is independently preferably 0 or 1.

Examples of the cation represented by the formula (Z1) or the formula (Z5) include the following.

The following are mentioned as a specific example of the cation in which the ring containing a sulfur atom was formed among the cations represented by a formula (Z5).

Specific examples of the cation (Z1) include the following.

Specific examples of the cation (Z2) include the following.

Specific examples of the cation (Z3) include the following.

Specific examples of the cation (Z4) include the following.

Furthermore, you may use the cation described in Unexamined-Japanese-Patent No. 2010-204646.

  The acid generator (II) is a combination of the above-described anions and organic cations. Although the above-mentioned anion and cation can be combined arbitrarily, the compound represented below is preferable. In the following formulae, the definition of the substituent has the same meaning as described above.

Further, the acid generator represented by the formula (II) is more preferably the following compound.

The acid generator (II) can be produced by a method known in the art.
For example, in the acid generator (II), the salt represented by the formula (IIa) in which L ^b1 is —CO—O— is the salt represented by the formula (IIa-1) and the formula (IIa-2). It can be produced by reacting the represented compound in a solvent. In the following formulas, each symbol represents the same meaning as above unless otherwise noted.
Examples of the solvent include chloroform.
Examples of the compound represented by the formula (IIa-2) include 4-hydroxy-1-methylpiperidine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, tropine and the like.
The salt represented by the formula (IIa-1) can be obtained by reacting the salt represented by the formula (IIa-3) with the compound represented by the formula (IIa-4).
The salt represented by the formula (IIa-3) can be synthesized, for example, by the method described in JP2008-13551A.

  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 C 1-17 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 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 fat. Examples thereof include cyclic saturated hydrocarbon groups, and a combination of two or more of 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). Group. 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 C 1-15 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 ^{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). Is 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 addition, when Y is an alkyl group and L ^{b1 ′} is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated carbonization at the bonding position with Y The methylene group of the hydrogen group is preferably replaced with an oxygen atom or a carbonyl group. In this case, the methylene group contained in the alkyl group of Y is not replaced with an oxygen atom or a carbonyl group. The same applies when the hydrogen atom contained in the alkyl group of Y and / or the divalent linear or branched saturated hydrocarbon group of L ^{b1 ′} is substituted with a substituent.

  Y is preferably an alicyclic hydrocarbon group having 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 any one of formulas (b1-1-1) to (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 the same as the cation represented by any one of the above formulas (Z1) to (Z4). is there.

  As an acid generator (B1), what is represented by either of a formula (B1-1)-a formula (B1-22) is mentioned, for example. Among them, those containing a triarylsulfonium 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 one of formulas (B1-22) is more preferable.

The content of the acid generator (II) is preferably 1 part by mass or more and more preferably 3 parts by mass or more with respect to 100 parts by mass of the resin (A). Moreover, Preferably it is 30 mass parts or less, More preferably, it is 25 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, 5: 95-95: 5, preferably 10: 90-90: 10, more preferably 15: 85-85: 15.
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-1)
A salt represented by the formula (II-1-1) was synthesized by the method described in JP 2008-127367 A.
10.00 parts of the salt represented by the formula (II-1-1) and 60.00 parts of acetonitrile were charged and stirred at 40 ° C. for 30 minutes. A solution containing the compound represented by the formula (II-1-3) was prepared by charging 4.44 parts of the compound represented by the formula (II-1-2) and stirring the mixture at 50 ° C. for 1 hour. Obtained. To the obtained solution containing the compound represented by the formula (II-1-3), 2.63 parts of the compound represented by the formula (II-1-4) was charged and stirred at 23 ° C. for 1 hour. The obtained reaction mass was charged with 80 parts of chloroform and 30 parts of ion-exchanged water, and stirred and separated. Water washing was performed 5 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 25 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained residue, 30 parts of tert-butyl methyl ether was added, stirred, stirred for 30 minutes, and filtered to obtain 4.48 parts of the salt represented by the formula (II-1).

Identification of the salt represented by the formula (II-1);
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 272.0

Synthesis Example 2 [Synthesis of salt represented by formula (II-2)]
A salt represented by the formula (II-2-1) was synthesized by the method described in JP 2008-127367 A.
10.00 parts of a salt represented by the formula (II-2-1) and 60.00 parts of acetonitrile were charged and stirred at 40 ° C. for 30 minutes to give a compound 4.44 represented by the formula (II-2-2). A solution containing a compound represented by the formula (II-2-3) was obtained by stirring 1 part at 50 ° C. for 1 hour. To the obtained solution containing the compound represented by the formula (II-2-3), 3.22 parts of the compound represented by the formula (II-2-4) was charged and stirred at 23 ° C. for 1 hour. The obtained reaction mass was charged with 80 parts of chloroform and 30 parts of ion-exchanged water, and stirred and separated. Water washing was performed 5 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 the resulting concentrate was dissolved by adding 30 parts of acetonitrile and concentrated. To the obtained residue, 50 parts of tert-butyl methyl ether was added and stirred, stirred for 30 minutes, and filtered to obtain 7.79 parts of the salt represented by the formula (II-2).

Identification of a salt represented by formula (II-2);
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 298.1

Synthesis Example 3: Synthesis of salt represented by formula (II-3)
50.00 parts of the compound represented by the formula (II-3-1) 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-3-2) (purity: 32%, manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over 30 minutes. Furthermore, this was heated up to 23 degreeC and 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-3-3). Compound 53.00 parts was obtained.
13.12 parts of a compound represented by the formula (II-3-4) and 73.86 parts of chloroform were charged into a reactor, stirred at 30 ° C. for 30 minutes, and represented by the formula (II-3-3). 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 this was separated to recover the organic layer. The recovered organic layer was charged with 50 parts of ion-exchanged water and subjected to a total of five washing operations such as stirring, standing and liquid separation. The obtained organic layer was charged with 2.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, 30 parts of acetonitrile and 150 parts of tert-butyl methyl ether were added to the resulting concentrate, the mixture was stirred, filtered, and the salt 14.28 represented by the formula (II-3-5). Got a part.

  10.32 parts of a salt represented by the formula (II-3-5) and 61.91 parts of acetonitrile were charged, stirred at 40 ° C. for 30 minutes, and a compound 4.44 represented by the formula (II-3-6). Prepared the department. By stirring this at 50 degreeC for 1 hour, the solution containing the compound represented by Formula (II-3-7) was obtained. In a solution containing the compound represented by the formula (II-3-7) thus obtained, 2.63 parts of the compound represented by the formula (II-3-8) was charged and stirred at 23 ° C. for 1 hour. To the obtained reaction mass, 100 parts of chloroform and 50 parts of ion-exchanged water were added, and the mixture was stirred and separated. Water washing was performed 5 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 the resulting concentrate was dissolved by adding 30 parts of acetonitrile and concentrated. To the obtained residue, 30 parts of tert-butyl methyl ether was added and stirred, stirred for 30 minutes, and filtered to obtain 10.81 parts of the salt represented by the formula (II-3).

Identification of a salt represented by formula (II-3);
MS (ESI (+) Spectrum): M ⁺ 277.1
MS (ESI (−) Spectrum): M ⁻ 272.0

Synthesis Example 4: Synthesis of salt represented by formula (B1-5)
The reactor was charged with 50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform, and stirred at 23 ° C. for 30 minutes. Thereafter, 16.27 parts of the compound represented by the formula (B1-5-b) was added dropwise, and the mixture was stirred at 23 ° C. for 1 hour to obtain a solution containing the salt represented by the formula (B1-5-c). Obtained. To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out. To this chloroform layer, 84.15 parts of ion-exchanged water was added and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and 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 Example 5 [Synthesis of salt represented by formula (B1-21)]

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

20.00 parts of a salt represented by the formula (B1-21-c), 2.84 parts of a compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.21 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for further 1 hour. After concentrating the obtained reaction solution, 200 parts of chloroform and 50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, the residue obtained was dissolved in 53.51 parts of acetonitrile, concentrated, 113.05 parts of tert-butyl methyl ether was added and stirred, and then filtered. 10.47 parts of the salt represented by the formula (B1-21) were obtained.

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

Synthesis Example 6 [Synthesis of salt represented by formula (B1-22)]

  11.26 parts of a salt represented by the formula (B1-22-a), 10.00 parts of a compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged at 23 ° C. For 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (B1-22-c). .75 parts were obtained.

11.71 parts of a salt represented by the formula (B1-22-c), 1.70 parts of a compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the obtained residue, stirred, and then filtered to obtain 6.84 parts of the salt represented by the formula (B1-22). Got.

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

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): monomer (a2-1-1)] was mixed at 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)] 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 A2-6 was obtained with a yield of 70%. This resin A2-6 has the following structural units.

Synthesis Example 19 [Synthesis of Resin X1]
Monomer (D) and monomer (a1-1-1) are used as monomers, and mixed so that the molar ratio [monomer (D): monomer (a1-1-1)] is 80:20. An amount of 1.5 mass times dioxane was added to prepare 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 17 and Comparative Example 1
<Preparation of resist composition>
As shown in Table 1, 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-1: salt represented by formula (II-1) II-2: salt represented by formula (II-2) II-3: salt represented by formula (II-3) B1-5: formula Salt represented by (B1-5) B1-21: Salt represented by formula (B1-21) B1-22: Salt represented by formula (B1-22) B2: Examples of WO2008 / 99869 and Synthesis according to the examples of JP2010-26478
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 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 at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 110 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature described in the “PB” column of Table 1. An ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 2-poles on axis illumination (σout = 0.97, σin) = 0.77, Y-polarized light], the line and space pattern was subjected to immersion exposure by changing the exposure amount in stages, and ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed on the hot plate at the temperature described in the “PEB” column of Table 1 for 60 seconds.
Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

  In the obtained resist pattern, the exposure amount at which the line width of the line pattern was 50 nm was defined as effective sensitivity.

<Evaluation of exposure margin (EL)>
In the exposure range of effective sensitivity ± 10%, the exposure amount is plotted on the horizontal axis, and the line width of a 50 nm line pattern formed with the exposure amount is plotted on the vertical axis. The absolute value of the slope of the regression line obtained from the plot is
What is 1.1 nm / (mJ / cm ² ) or less
1.1nm / (mJ / cm ^{2) beyond, 1.5nm / (mJ / cm 2} ) ○ the following:,
What exceeded 1.5 nm / (mJ / cm < ² >) was set as x.
The results are shown in Table 2. In Table 2, the numbers in parentheses indicate the absolute value of the slope of the regression line.

<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 2.

  According to the resist composition of the present invention, a negative resist pattern can be produced with an excellent exposure margin (EL), and the number of defects in the obtained resist pattern is small. Therefore, it is useful for fine processing of semiconductors.

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,
A structural unit represented by the formula (a1-1), a structural unit represented by the formula (a1-0), a structural unit represented by the formula (a1-2), and a formula (a1-5). A resin having at least two acid labile groups with at least one selected from the group consisting of structural units, 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),
R ^b1 and R ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W ^b1 represents a heterocyclic ring having 2 to 36 carbon atoms.
R ^b3 represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^b4 represents a hydrocarbon group having 1 to 6 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
m represents an integer of 0-6. When m is 2 or more, the plurality of R ^b4 are the same or different.
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%. The resist composition according to claim 1, wherein L ^b1 in the formula (II) is a group represented by the formula (L1-1).
[In Formula (L1-1), L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. * Represents a bond with —C (R ^b1 ) (R ^b2 ) —. ] (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 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 with an organic solvent .