JP2015147925A - resin and resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin for resist compositions, from which a resist pattern in a good shape can be manufactured.SOLUTION: A resin (A1) includes a structural unit represented by a formula (a2-2) and a unit represented by (a4), having no acid-labile group.

Description

  The present invention relates to a resin and a resist composition.

  Patent Document 1 describes a resist composition comprising a resin comprising a combination of the following structural units, a resin having an acid labile group, and an acid generator.

  Patent Document 2 describes a resin comprising a combination of the following structural units.

JP 2008-203452 A Special table 2013-506865 gazette

  In the resist pattern formed by the above resist composition, the shape may not be satisfactory.

The present invention includes the following inventions.
[1] (A1) A resin containing a structural unit represented by the formula (a2-2) and a structural unit represented by the formula (a4) and having no acid labile group.

[In the formula (a2-2),
R ^a40 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a41 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
mb represents the integer of 0-4. When mb is an integer greater than or equal to 2, several ^Ra41 may mutually be same or different. ]

[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 24 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]
[2] The structural unit represented by the formula (a4) is represented by the structural unit represented by the formula (a4-0), the structural unit represented by the formula (a4-1), or the formula (a4-2). The resin according to claim 1, which is at least one selected from the group consisting of a structural unit represented by formula (a4-3) and a structural unit represented by formula (a4-3):

[In the formula (a4-0),
R ^f1 represents a hydrogen atom or a methyl group.
R ^f2 represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]

[In the formula (a4-1),
R ^f3 represents a hydrogen atom or a methyl group.
L ³ represents 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.
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 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.
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 bivalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents a C ^1-17 saturated hydrocarbon group which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom. ]
[3] A resist composition comprising the resin according to [1] or [2], a resin having an acid labile group, and an acid generator.
[4] A step of applying the resist composition according to (1) [3] 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 containing the resin of the present invention, a resist pattern can be produced with a good shape.

In the present specification, "(meth) acrylic monomer" means at least one monomer having a _"CH 2 = _CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resin (A1)>
The resin (A1) is composed of a structural unit represented by the formula (a2-2) (hereinafter sometimes referred to as “structural unit (a2-2)”) and a structural unit represented by the formula (a4) (hereinafter referred to as “structure”). And a resin having no acid labile group.
The acid labile group means 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.

[In the formula (a2-2),
R ^a40 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a41 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
mb represents the integer of 0-4. When mb is an integer greater than or equal to 2, several ^Ra41 may mutually be same or different. ]

^Examples of the halogen atom for R ^a40 include a fluorine atom, a chlorine atom, and a bromine atom.
^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in Ra ⁴⁰ include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl Groups and n-perfluorohexyl groups.
R ^a40 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group for R ^a41 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group.
^Examples of the alkoxy group for R ^a41 include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a tert-butoxy group. A C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is more preferable.
^Examples of the acyl group for R ^a41 include an acetyl group, a propionyl group, and a butyryl group.
^Examples of the acyloxy group for R ^a41 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a41 is preferably a methyl group.
mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxyl group is preferably bonded to the o-position or p-position, and more preferably bonded to the p-position.

Examples of the monomer for deriving the structural unit (a2-2) include monomers described in JP2012-12577A.
The structural unit (a2-2) is represented by formula (a2-2-1), formula (a2-2-2), formula (a2-2-3), and formula (a2-2-4), respectively. The thing of a formula (a2-2-1) or a formula (a2-2-2) is more preferable.

  The structural unit (a2-2) is derived from a compound represented by the formula (a2′-2) (hereinafter sometimes referred to as “compound (a2′-2)”).

[In the formula (a2′-2), R ^a40 , R ^a41 and mb represent the same meaning as described above. ]

  The compound (a2′-2) may be a commercially available product, such as condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride) with a substituted or unsubstituted hydroquinone. You may manufacture by a well-known method. Examples of the compound (a2′-2) include compounds represented by the following.

  The structural unit represented by the formula (a4) is represented by the following.

[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 24 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

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) -2,2 , 2-trifluoroethyl group, 1- (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, 1- (perfluoroethyl) -2,2,3,3,3-pentafluoro Propyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis ( (Trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group 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, pe Fluorinated alkyl groups such as a fluoro-cyclopentylmethyl group and perfluorohexyl group; perfluorocyclohexyl group, alicyclic hydrocarbon group having a fluorine atom such as perfluorinated adamantyl group.

  As the structural unit (a4), a structural unit represented by any one of formulas (a4-0) to (a4-2) (hereinafter referred to as “structural unit (a4-0) to structural unit (a4-2)”). May be preferred).

[In the formula (a4-0),
R ^f1 represents a hydrogen atom or a methyl group.
R ^f2 represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]

[In the formula (a4-1),
R ^f3 represents a hydrogen atom or a methyl group.
L ³ represents 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.
R ^f4 represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms.
However, the total number of carbon atoms of L ³ and R ^f4 is 20. The number of carbons represents the number of carbons before the methylene group is replaced with an oxygen atom or a carbonyl group. ]

[In the formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ⁴ represents 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.
R ^f6 represents a hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms.
However, the total number of carbon atoms of ^{L 4} and ^{R f6} are 20. ]

In the formula (a4-0) to the formula (a4-2), the divalent saturated hydrocarbon group is a divalent aliphatic saturated hydrocarbon group, a divalent alicyclic saturated hydrocarbon group, or a combination thereof. Groups.
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 divalent monocyclic alicyclic saturated hydrocarbon group include a cyclohexanediyl group, and examples of the divalent polycyclic alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group. It is done. Of these, alkanediyl groups are preferred.
Examples of the saturated hydrocarbon group having a fluorine atom include the same groups as those for R ⁴ in the formula (a4).

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

In the above structural unit, a structural unit in which a methyl group corresponding to R ³ is replaced by a hydrogen atom can also be given as a specific example of the structural unit (a4-0).

  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 ³ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a4-1).

  As the structural unit (a4-2), the following may be mentioned.

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 (a4-1).

  As the structural unit (a4), a structural unit represented by the formula (a4-3) (hereinafter sometimes referred to as “structural unit (a4-3)”) can also be exemplified.

[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 bivalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents a C ^1-17 saturated hydrocarbon group which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom.
However, the total carbon number of L ⁵ , R ^f13 and R ^f14 is 18. ]

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-diyl group. And straight-chain alkanediyl groups such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as diyl group, 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

Examples of the divalent saturated hydrocarbon group for A ^f13 include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic 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 divalent monocyclic alicyclic saturated hydrocarbon group include a cyclohexanediyl group, and examples of the divalent polycyclic alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group. It is done.
The saturated hydrocarbon group having a fluorine atom in A ^f13 is preferably an aliphatic saturated hydrocarbon group having a fluorine atom, and more preferably a perfluoroalkanediyl group.
Examples of the divalent aliphatic saturated hydrocarbon group having a fluorine atom include a perfluoroalkanediyl group such as a difluoromethylene group, a perfluoroethylene group, a perfluoropropanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group.
The divalent alicyclic saturated hydrocarbon group having a fluorine atom may be monocyclic or polycyclic. Examples of the divalent alicyclic saturated hydrocarbon group having a monocyclic fluorine atom include a perfluorocyclohexanediyl group. Examples of the divalent alicyclic saturated hydrocarbon group having a polycyclic fluorine atom include a perfluoroadamantanediyl group.

Examples of the saturated hydrocarbon group for A ^f14 include an aliphatic saturated hydrocarbon group, an alicyclic saturated hydrocarbon group, and a group in which an aliphatic saturated hydrocarbon group and an alicyclic saturated hydrocarbon group are combined.
Examples of the aliphatic saturated hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, and heptyl group, and alicyclic hydrocarbon groups include monocyclic and polycyclic The monocyclic alicyclic hydrocarbon group includes a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, and a cyclohexyl group, and a polycyclic alicyclic hydrocarbon group. Examples of the group include an adamantyl group and a norbornyl group. Examples of the group obtained by combining an aliphatic saturated hydrocarbon group and an alicyclic saturated hydrocarbon group include an adamantylmethyl group and a norbornylmethyl group.
Examples of the aliphatic saturated hydrocarbon group having a fluorine atom include trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, Perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 1, Examples thereof include 1,1,2,2,3,3,4,4-nonafluoropentyl group and pentyl group, perfluorohexyl group, perfluoroheptyl group, octyl group and perfluorooctyl group.
The alicyclic saturated hydrocarbon group having a fluorine atom may be monocyclic or polycyclic. Examples of the alicyclic saturated hydrocarbon group having a monocyclic fluorine atom include a perfluorocyclohexyl group. Examples of the alicyclic saturated hydrocarbon group having a polycyclic fluorine atom include a perfluoroadamantyl group.
Examples of the group having a fluorine atom and a combination of an aliphatic saturated hydrocarbon group and an alicyclic saturated hydrocarbon group include a perfluoroadamantylmethyl group.

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.
At least one of A ^f13 and A ^f14 has a fluorine atom, but it is preferable that A ^f13 has a fluorine atom.

  As the structural unit (a4-3), the following may be mentioned.

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 (a4-3).

  The structural unit (a4-0) is derived from a compound represented by the formula (a4′-0) (hereinafter sometimes referred to as “compound (a4′-0)”).

[In formula (a4′-0), R ^f1 and R ^f2 represent the same meaning as described above. ]

Compound (a4′-0) may be a commercially available product, or condenses (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride etc.) and alcohol (HO—R ^f2 ). What was manufactured by well-known methods, such as these, may be used. Examples of the compound (a4′-0) include compounds represented by the following.

  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 a compound represented by the formula (a4′-1-1) and a compound represented by the formula (a4′-1-2) in the presence of a basic catalyst. It can manufacture by making it react under.

[Wherein, R ^f3 , R ^f4 and L ³ represent the same meaning as described above. ]

Examples of the solvent include tetrahydrofuran, and examples of the basic catalyst include pyridine.
Examples of the compound represented by the formula (a4′-1-1) include hydroxyethyl methacrylate. The compound represented by the formula (a4′-1-1) may be a commercially available product, (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride, etc.), and a diol (HO— L ³ —OH) may be obtained by a known method such as condensation.
As a compound represented by the formula (a4′-1-2), a 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 a compound represented by formula (a4′-2-1) and a compound represented by formula (a4′-2-2) in a solvent in the presence of a catalyst. It can be produced by reacting. Examples of the solvent include dimethylformamide. Examples of the catalyst include potassium carbonate and potassium iodide.

The compound represented by the formula (a4′-2-1) is preferably a compound (commercially available) that can be easily obtained from the market. Such commercial products include methacrylic acid and the like.
The compound represented by the formula (a4′-2-2) is obtained by reacting the compound represented by the formula (a4′-2-3) with the 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 .
The compound represented by the formula (a4′-2-2) when L ⁴ is a methylene group is produced by using chloroacetyl chloride or the like as the compound represented by the formula (a4′-2-3). can do.
As the compound represented by the formula (a4′-2-4), an appropriate alcohol can be used depending on the type of R ^f6 .
The compound represented by the formula (a4′-2-2), in which R ^f6 is an aliphatic hydrocarbon group substituted with a fluorine atom, includes, for example, a compound represented by the formula (a4′-2-4): It can be produced by using 2,2,3,3,4,4,4-heptafluoro-1-butanol or the like.

  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) is obtained by reacting the compound represented by the formula (a4′-3-1) with the carboxylic acid represented by the formula (a4′-3-2). Can be obtained.
This reaction is usually performed in the presence of a solvent. Examples of the solvent include tetrahydrofuran and toluene. 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 a compound represented by a formula (a4'-3-1), a commercial item may be used and it may manufacture and use by a well-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) 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.

The content of the structural unit (a2-2) in the resin (A1) is preferably 20 to 90 mol% with respect to the total of all the structural units of the resin (A1) in terms of the shape of the resist pattern. 40 to 85 mol% is more preferable, and 60 to 80 mol% is more preferable.
The content of the structural unit (a4) in the resin (A1) is preferably 10 to 80 mol% with respect to the total of all the structural units of the resin (A1) in terms of the shape of the resist pattern. More preferably, it is -60 mol%, and it is further more preferable that it is 20-40 mol%.
When the content of the structural unit (a2-2) and the structural unit (a4) is within the above range, a resist pattern having a better shape can be produced.

Each of the structural unit (a2-2) and the structural unit (a4) constituting the resin (A1) has only one kind or a combination of two or more kinds, and optionally has no acid labile group described later. One or more monomers can be combined and produced by a known polymerization method (for example, radical polymerization method).
Resin (A1) does not have an acid labile group.
The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 7,000 or more, still more preferably 10,000 or more), 80,000 or less (more preferably 50,000 or less, more preferably 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 resist composition of the present invention is a resist composition containing a resin (A) and an acid generator (B). Resin (A) contains resin (A1) and resin (A2) which has an acid labile group.
The resist composition of the present invention preferably further contains a solvent (E) or a basic compound (C), and more preferably contains a solvent (E) and a basic compound (C).

<Resin (A2)>
The resin (A2) is a resin having an acid labile group, and a resin having a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”). The resin (A2) preferably has a property of decomposing by the action of an acid and reducing the solubility in butyl acetate or 2-heptanone.

<Structural unit (a)>
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 thereof, or R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms.
na represents 0 or 1.
* Represents a bond. ]

[In formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

^Examples of the alkyl group of R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-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 a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

Examples of the group combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
na is preferably 0.

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

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

Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and 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.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include groups in which one hydrogen atom has been removed from the hydrocarbon groups of R ^{a1 ′ to} R ^{a3 ′} .
Of R ^{a1 ′} and R ^{a2 ′} , at least one 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), preferably a structural unit represented by the formula (a1-0), a structure represented by the formula (a1-1) Examples thereof include a unit or a structural unit represented by formula (a1-2). 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 with a carbonyl group.
R ^a01 each independently represents a hydrogen atom or a methyl group.
R ^{a02 to} R ^a04 each independently ^represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof. ]

[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 represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, and more preferably —O—. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as those ^exemplified for R ^{a1 to} R ^a3 of formula (1).
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The carbon number of the alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably 8 or less, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

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

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

  The content of the structural unit represented by the formula (a1-0) is preferably 3 to 60 mol%, more preferably 4 to 55 mol%, based on the total of all the structural units of the resin (A). is there.

  As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned. 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.

  As the monomer (a1-2), 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate and 1-isopropylcyclohexane-1-yl ( And (meth) acrylate. Monomers represented by formula (a1-2-1) to formula (a1-2-12) are preferred, and formula (a1-2-3) to formula (a1-2-4) and formula (a1-2-9) ) To (a1-2-10) are more preferable, and monomers represented by the formula (a1-2-3) and (a1-2-9) are more preferable.

  When the resin (A2) includes the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is generally 10 to 10% with respect to the total of all the structural units of the resin (A2). It is 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%.

  Furthermore, examples of the structural unit (a1) having the group (1) include a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Moreover, the monomer which derives the structural unit (a1-3) may be referred to as a monomer (a1-3).

[In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxy group, a cyano group, a hydrogen atom, or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, and the aliphatic hydrocarbon group and The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—. -Or -CO- may be substituted.
R ^{a10 to} R ^a12 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, or R ^a10 and R ^a11 is bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the carbon atom to which they are bonded. ]

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

Examples of the aliphatic hydrocarbon group which may have a hydroxyl group of ^Ra9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ^a13 include a methyl group, an ethyl group, and a propyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by Ra13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3- Yl group and 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group for R ^{a10 to} R ^a12 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, Examples include n-heptyl group, 2-ethylhexyl group, n-octyl group and the like.
The alicyclic hydrocarbon group of R ^{a10 to} R ^a12 may be monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
As -C (R ^a10 ) (R ^a11 ) (R ^a12 ) in the case where R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group together with the carbon atom to which they are bonded, Groups are preferred.

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

  Since the resin (A2) containing the structural unit (a1-3) contains a sterically bulky structural unit, the resist composition of the present invention containing such a resin (A2) is more expensive. A resist pattern can be obtained with resolution. Further, since a rigid norbornane ring is introduced into the main chain, the resulting resist pattern tends to be excellent in dry etching resistance.

  When resin (A2) contains structural unit (a1-3), it is preferable that the content is 10-95 mol% with respect to the sum total of all the structural units of resin (A2), 15-90 mol. % Is more preferable, and 20 to 85 mol% is still more preferable.

  As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). Can be mentioned.

[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and ^{R a35} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon ^{atoms, R a36} may represent a hydrocarbon group having 1 to 20 carbon ^{atoms, R a35} and ^{R a36} are bonded to each other To form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by —O— or —S—. Good. ]

^Examples of the alkyl group for R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom for R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
The R ^a34 and ^{R a35,} include the same groups as ^{R 14} and ^{R 15} of formula (2).
R ^a36 includes an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by a combination thereof. Can be mentioned.

In formula (a1-2), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group for R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. It is a group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group in R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

  Examples of the monomer for deriving the structural unit monomer (a1-4) include monomers described in JP2010-204646A. Among these, monomers represented by formula (a1-4-1) to formula (a1-4-8) are preferable, and formula (a1-4-1) to formula (a1-4-5) and formula (a1- The monomers represented by 4-8) are more preferable.

  When resin (A2) has a structural unit (a1-4), it is preferable that the content rate is 10-95 mol% with respect to the sum total of all the structural units of resin (A2), 15-90 More preferably, it is mol%, and further preferably 20-85 mol%.

  As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”) Is also included).

[In the formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — (CH ₂ ) _{h 3} —CO—L ⁵⁴ —, h 3 represents an integer of 1 to 4, and * represents a bond to L ⁵¹ .
L ^{51 to} L ⁵⁴ each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group and a trifluoromethyl group. Groups.
In Formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
One of L ⁵² and L ⁵³ is preferably —O—, and the other is preferably —S—.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

  As a monomer which introduce | transduces structural unit (a1-5), the monomer described in Unexamined-Japanese-Patent No. 2010-61117 is mentioned, for example. Among these, monomers represented by formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by formula (a1-5-1) or formula (a1-5-2) are preferable. Is more preferable.

  When resin (A2) has a structural unit (a1-5), it is preferable that the content rate is 1-50 mol% with respect to the sum total of all the structural units of resin (A2), 3-45 It is more preferable that it is mol%, and it is further more preferable that it is 5-40 mol%.

  In the resin (A2), the content of the structural unit (a) is preferably 30 to 98 mol%, more preferably 35 to 90 mol%, based on the total of all the structural units of the resin (A2). More preferably, it is 40-80 mol%.

<Structural unit without acid labile group>
The monomer for deriving a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) is not particularly limited as long as it does not have an acid labile group, and is well known in the resist field. Can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, when a high energy beam such as a KrF excimer laser (248 nm), an electron beam or EUV (ultra-ultraviolet light) is used as an exposure light source, the structural unit (a2) It is preferable to use the structural unit (a2) having a phenolic hydroxy group. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) having an alcoholic hydroxy group is preferable as the structural unit (a2), and the structural unit (a2-1) is more preferable. As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

Examples of the structural unit (a2) having a phenolic hydroxy group include the following structural units.
Especially, what is represented by a formula (a2-0-1) or a formula (a2-0-2) is more preferable.
Examples of the monomer that derives the structural unit (a2-0) include monomers described in JP 2010-204634 A.

  The resin (A) containing the structural unit (a2-0) is subjected to a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that derives the structural unit (a2-0) is protected with a protective group, and then deprotected. It can be manufactured by processing. However, when the deprotection treatment is performed, the acid labile group of the structural unit (a1) needs to be not significantly impaired. Examples of such protecting groups include acetyl groups.

  When the resin (A2) has a structural unit (a2) having a phenolic hydroxy group, the content is preferably 5 to 95 mol% based on the total of all the structural units of the resin (A2). More preferably, it is 10-80 mol%, and it is further more preferable that it is 15-80 mol%.

  Examples of the structural unit (a2) having an alcoholic hydroxy group include the following structural units.

As the structural unit (a2), a structural unit represented by any one of the formulas (a2-1-1) to (a2-1-4) is preferable, and the formula (a2-1-1) or the formula (a2) The structural unit represented by (1-3) is more preferable.
Examples of the monomer for deriving the structural unit (a2) having an alcoholic hydroxy group include monomers described in JP2010-204646A.

  When the resin (A2) contains a structural unit (a2) having a phenolic hydroxy group, the content is usually 1 to 45 mol%, preferably 1 with respect to the total of all the structural units of the resin (A2). It is -40 mol%, More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But you can. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure is used. The structural unit (a3) may contain two or more kinds. Examples of the structural unit (a3) include the following structural units.

As monomers for deriving the structural unit (a3), monomers described in JP 2010-204646 A, monomers described in JP 2000-122294 A, monomers described in JP 2012-41274 A are listed. Can be mentioned. As the structural unit (a3), the formula (a3-1-1) to the formula (a3-1-6), the formula (a3-2-1) to the formula (a3-2-4), and the formula (a3-3) 1) to a structural unit represented by any one of the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-6), the formula (a3-1-1), It is represented by any one of formula (a3-1-2), formula (a3-2-3) to formula (a3-2-4), and formula (a3-4-1) to formula (a3-4-2). The structural unit represented by Formula (a3-1-1), Formula (a3-2-3), or Formula (a3-4-2) is more preferable.
When the resin (A2) contains the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total of all the structural units of the resin (A2). Yes, more preferably 10 to 60 mol%.

  The resin (A2) may have a structural unit other than the above. As such a structural unit, a structural unit derived from a carboxy group-containing monomer such as acrylic acid or methacrylic acid, a structural unit derived from styrene, a structural unit derived from alkoxystyrene, a structural unit derived from acyloxystyrene, a formula ( and the structural unit represented by a5-1).

The structural unit derived from the alkoxystyrene is a structural unit in which the hydroxy group of the structural unit (a2-0) is substituted with an alkoxy group. Monomers that lead to the structural unit include methoxystyrene, ethoxystyrene, isopropoxystyrene, and tert-butoxystyrene.
The structural unit derived from the acyloxystyrene is a structural unit in which the hydroxy group of the structural unit (a2-0) is substituted with an acyloxy group. Examples of the monomer for deriving the structural unit include benzoyloxystyrene, acetyloxystyrene, and pivaloyloxystyrene.

  The structural unit represented by the formula (a5-1) is represented by the following.

[In the formula (a5-1),
R ^a50 represents a hydrogen atom or a methyl group.
R ^a51 represents a saturated hydrocarbon group having 1 to 18 carbon atoms. ]

^Examples of the saturated hydrocarbon group for R ^a51 include an alkyl group, an alicyclic saturated hydrocarbon group, and a group obtained by combining these.
^Examples of the alkyl group for R ^a51 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 saturated hydrocarbon group for R ^a51 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated 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 saturated hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). The alicyclic saturated hydrocarbon group for R ^a51 preferably has 3 to 16 carbon atoms.

  Examples of the group in which an alkyl group and an alicyclic saturated hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

  Examples of the structural unit (a5-1) include the following structural units.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a50 is replaced by a hydrogen atom can also be given as a specific example of the structural unit (a5-1).

  When resin (A2) contains another structural unit, it is preferable that the content rate is 1-50 mol% with respect to the sum total of all the structural units of resin (A2), and is 3-30 mol%. It is more preferable.

The resin (A2) is preferably a resin composed of the structural unit (a) and the structural unit (s).
The structural unit (a) is preferably at least one selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit ( a1-1) or the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group).
The structural unit (s) is preferably at least one selected from 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 selected from the structural unit (a3-1), the structural unit (a3-2), and the formula (a3-4).

  The resin (A2) preferably contains 15 mol% or more of structural units derived from the monomer having an adamantyl group (particularly the structural unit (a1-1)) with respect to the total structural units (a). When the content of the structural unit having an adamantyl group is large, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A2) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The 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, and further preferably 15,000 or less).

  The content ratio (mass ratio) of the resin (A1) and the resin (A2) in the resin (A) is usually (resin (A1): resin (A2) =) 0.01: 10 to 5:10, preferably 0.8. 05:10 to 3:10, more preferably 0.1: 10 to 2:10, and still more preferably 0.2: 10 to 1:10.

<Resin other than resin (A1) and (A2)>
The resist composition of the present invention includes a resin other than the above-described resins (A1) and (A2), for example, a structural unit derived from the acid-labile monomer (a1) described above, a structural unit derived from an acid-stable monomer, A resin having at least one selected from structural units derived from known monomers used in the field may be contained.
When the resist composition of this invention contains resin other than resin (A1) and (A2), these content rates are normal with respect to the total amount of resin (A) contained in the resist composition of this invention. It is 0.1-50 mass%, Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%.

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

<Acid generator (B)>
The acid generator (B) may be a nonionic acid generator or an ionic acid generator.
Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates) and sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane). 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 acid generator (B) is preferably an acid generator that generates sulfonic acid.
The acid generator (B) is preferably an acid generator having no fluorine atom.
The acid generator (B) is more preferably an acid generator that generates a sulfonic acid having no fluorine atom.

  As the acid generator (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, Kaisho 62-153853, JP 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712, etc. The compound which generate | occur | produces an acid by the radiation as described in 1 can be used.

As the acid generated from the acid generator, sulfonic acid is preferable, and sulfonic acid containing no fluorine atom is more preferable.
Two or more acid generators (B) may be used. When the acid generator (B) includes an acid generator that generates a sulfonic acid not containing a fluorine atom, the content of the acid generator is preferably 50 masses with respect to the total amount of the acid generator (B). % Or more, more preferably 60% by mass or more, and still more preferably 90% by mass or more.

  As the nonionic acid generator that generates a sulfonic acid containing no fluorine atom, a compound represented by the formula (B1) is preferable.

[In Formula (B1), R ^b1 and R ^b2 each independently represent a hydrocarbon group having 1 to 10 carbon atoms. ]

Examples of the hydrocarbon group in R ^b1 and R ^b2 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining them. Examples of the alkyl group 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 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 an adamantyl group and a norbornyl group.
Aromatic hydrocarbon groups include phenyl, naphthyl, p-methylphenyl, p-tert-butylphenyl, tolyl, xylyl, cumenyl, mesityl, 2,6-diethylphenyl, 2- And aryl groups such as methyl-6-ethylphenyl.
R ^b1 is preferably a butyl group, a cyclohexyl group, a methylcyclohexyl group, or a butylcyclohexyl group.
R ^b2 is preferably a butyl group, a cyclohexyl group, a methylcyclohexyl group, or a butylcyclohexyl group.
R ^b1 and R ^b2 are preferably the same group.

  Specific examples of the compound represented by the formula (B1) include the following compounds.

  As the ionic acid generator that generates a sulfonic acid not containing a fluorine atom, a salt represented by the formula (B2) is preferable.

[In the formula (B2),
R ^b3 represents a hydrocarbon group having 1 to 24 carbon atoms, the hydrogen atom contained in the hydrocarbon group may be substituted with a hydroxy group or a carboxy group, and the methylene group contained in the hydrocarbon group is , Oxygen atom or carbonyl group may be substituted.
A ⁺ represents an organic cation. ]

The hydrocarbon group for R ^b3 is an aliphatic hydrocarbon group having 1 to 24 carbon atoms, an alicyclic hydrocarbon group having 3 to 24 carbon atoms, an aromatic hydrocarbon group having 6 to 24 carbon atoms, or a combination thereof. It is a group of formula 24 or less.
Aliphatic hydrocarbon groups include methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, hexyldecyl And alkyl groups such as a heptadecyl group, an octadecyl group and an icosyl group.
As the alicyclic hydrocarbon group, a monocyclic alicyclic hydrocarbon group such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group; .1] Polycyclic alicyclic hydrocarbon groups such as heptyl group and adamantyl group.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, biphenyl, phenanthryl Groups, aryl groups such as 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, 2,4,6-trimethylphenyl group, 2,4,6-triisopropylphenyl group, and the like.
Examples of the group obtained by combining an aliphatic hydrocarbon group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, and an isobornyl group.
Examples of the group obtained by combining an aliphatic hydrocarbon group and an aromatic hydrocarbon group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.

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

  Examples of the group in which the methylene group contained in the hydrocarbon group is replaced with an oxygen atom or a carbonyl group include the following groups.

R ^b3 is preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms or an alicyclic hydrocarbon group having 3 to 24 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is a hydroxy group or a carboxy group The methylene group contained in the aromatic hydrocarbon group and the alicyclic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^b3 is more preferably a group represented by the formula (B3).

[In the formula (B3),
R ^b30 represents a hydroxy group, a carboxy group or a hydrocarbon group having 1 to 8 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
mx represents an integer of 0 to 5. When mx is 2 or more, when a plurality of R ^b30 may be the same or different from each other, the further plurality of R ^b30 represents a hydrocarbon group having 1 to 8 carbon atoms, the total number of carbon atoms is 18 or less is there.
* Represents a bond with SO ₃ ^— . ]

Examples of the hydrocarbon group having 1 to 8 carbon atoms in R ^b30 include an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 8 carbon atoms, and an aromatic hydrocarbon having 6 to 8 carbon atoms. A group having 8 or less carbon atoms and a combination thereof. Preferably it is a C1-C8 aliphatic hydrocarbon group. Specifically, the same thing as ^Rb1 is mentioned.
R ^b30 is preferably a hydroxy group, a carboxy group, or an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Preferably it is a C1-C8 aliphatic hydrocarbon group.
mx is preferably an integer of 0 to 3.
When mx is 2 to 3, a plurality of R ^b30 are preferably the same group.

  The group represented by the formula (B3) is preferably a phenyl group, a 2,4,6-trimethylphenyl group or a 2,4,6-triisopropylphenyl group.

  Examples of the sulfonate anion of the formula (B2) include anions represented by any of the formulas (B2-a-1) to (B2-a-19), and preferably the formula (B2-a-8) To an anion represented by any one of formulas (B2-a-16), more preferably formula (B2-a-8) to formula (B2-a-11), formula (B2-a-15) and An anion represented by any one of the formulas (B2-a-16).

A ⁺ is preferably a cation represented by any one of formulas (b2-1) to (b2-4).

[In Formula (b2-1)-Formula (b2-4),
R ^{b4 to} R ^b6 each independently represent an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, or R ^b4 And R ^b5 together form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) containing a sulfur atom. The hydrogen atom contained in the alkyl group is substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 represent the integer of 0-5 independently of each other. When m2 is 2 or more, the plurality of R ^b7 may be the same or different, and when n2 is 2 or more, the plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a C 1-18 alkyl group or a C 3-18 alicyclic hydrocarbon group, or R ^b9 and R ^b10 are taken together They are bonded to each other together with the sulfur atom to be bonded to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
^Rb12 represents a C1- ^C12 alkyl group, a C3- ^C18 alicyclic hydrocarbon group, or a C6-C18 aromatic hydrocarbon group. The hydrogen atom contained in the alkyl group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is an alkoxy group having 1 to 12 carbon atoms. Alternatively, it may be substituted with an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) together with —CH—CO— to which they are bonded, The contained methylene group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When s2 is 2 or more The plurality of R ^b15 may be the same or different, and when t2 is 2 or more, the plurality of R ^b18 may be the same or different. ]

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. . The alkyl group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
Examples of the alkyl group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.

In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 4 to 12 carbon atoms.

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

Examples of the aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-adamantyl group. Substituted or unsubstituted phenyl groups such as phenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group; biphenylyl group, naphthyl group, phenanthryl group and the like.
Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a 4-methoxyphenyl group.
Examples of the alkyl group in which a hydrogen atom is substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.
In addition, when an alkyl group or an alicyclic hydrocarbon group is contained in an aromatic hydrocarbon group, a C1-C12 alkyl group and a C3-C18 alicyclic hydrocarbon group are preferable.

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

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

The hydrocarbon groups for R ^{b4 to} R ^b6 are preferably independently of each other an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon having 6 to 18 carbon atoms. A hydrogen atom contained in the alkyl group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic carbonization The hydrogen atom contained in the hydrogen group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, or 1 to 1 carbon atoms. It may be substituted with 12 alkoxy groups.

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

  As a cation represented by Formula (b2-1)-Formula (b2-4), what was described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example.

  Preferred examples of the salt represented by the formula (B2) include the following compounds.

  The acid generator (B) is preferably an acid generator containing a compound represented by the formula (B1) and a salt represented by the formula (B2). The content ratio of the compound represented by the formula (B1) and the salt represented by the formula (B2) is based on mass, preferably represented by the compound represented by the formula (B1): Formula (B2). Compound = 50: 50 to 95: 5, more preferably 60:40 to 90:10.

<Solvent (E)>
The content of the solvent (E) is 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and 99.9% by mass or less, preferably 99% by mass or less in the resist composition. . 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.

  Solvents (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 Esters such as ethyl; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

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

  As the quencher (C), 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine , Hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, tri Hexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexyl Amine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine , Ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenyl Ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, 2,2′-methylenebisaniline, imida , 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4 ′ -Dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipycolylamine, bipyridine and the like, preferably diisopropylaniline, particularly preferably 2,6- Diisopropylaniline is mentioned.

  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.

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

<Weak acid inner salt (D)>
The weak acid inner salt (D) is a compound represented by the formula (D).

[In the formula (D),
R ^D1 and R ^D2 are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, or an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group, or a halogen atom.
m ′ and n ′ each independently represents an integer of 0 to 4, and when m ′ is 2 or more, a plurality of R ^D1 may be the same or different, and when n ′ is 2 or more, The plurality of R ^D2 may be the same or different. ]

In the compound represented by the formula (D), the hydrocarbon groups of R ^D1 and R ^D2 are a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, and a monovalent aromatic hydrocarbon. And groups formed by combining these groups.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and nonyl group.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be either saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, and cyclododecyl group, norbornyl group, adamantyl group, and the like.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4- Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group , Aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the group formed by combining these include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (for example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl- 1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.).

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

In the formula (D), R ^D1 and R ^D2 are each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or 2 to 2 carbon atoms. 4 is preferably an acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom.
m ′ and n ′ are each independently preferably an integer of 0 to 2, and more preferably 0. When m ′ is 2 or more, the plurality of R ^D1 may be the same or different, and when n ′ is 2 or more, the plurality of R ^D2 may be the same or different.

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

  Compound (D) can be produced by the method described in “Tetrahedron Vol. 45, No. 19, p6281-6296”. Moreover, the compound (D) can use the compound marketed.

  The content of the quencher (C) is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass in the solid content of the resist composition.

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

<Preparation of resist composition>
The resist composition of the present invention is prepared by mixing the resin (A) and the acid generator (B) and, if necessary, the solvent (E), the quencher (C) and other components (F). 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.

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

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

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As an exposure light source, a laser beam emitting in the ultraviolet region such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), a solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do. In this specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, exposure is usually performed through a mask corresponding to a required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

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

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

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 substantially only the organic solvent. More preferably.
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 or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially. More preferably, it is only butyl acetate and / or 2-heptanone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
During development, the development may be stopped by substituting a solvent of a different type from the solvent contained in 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 includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly an electron. It is suitable as a resist composition for line (EB) exposure or a resist composition for EUV exposure, and is useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “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

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

  Hereinafter, these monomers are referred to as “monomer (a2′-2-1)” or the like according to the formula number.

Synthesis Example 1 [Synthesis of Resin A1-1]
As the monomer, monomer (a2′-2-1) and monomer (a4′-0-1) are used, and the molar ratio (monomer (a2′-2-1): monomer (a4′-0-1)) is The mixture was mixed to 70:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added with respect to the total amount of monomers, respectively, and heated at 75 ° 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 A1-1 having a weight average molecular weight of 1.6 × 10 ^{4 in} a yield of 91%. . This resin A1-1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin A1-2]
As the monomer, monomer (a2′-2-1) and monomer (a4′-0-1) are used, and the molar ratio (monomer (a2′-2-1): monomer (a4′-0-1)) is It mixed so that it might be set to 30:70, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added with respect to the total amount of monomers, respectively, and heated at 75 ° 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 having a weight average molecular weight of 9.0 × 10 ^{3 in} a yield of 88%. . This resin A1-2 has the following structural units.

Synthesis Example 3 [Synthesis of Resin A1-3]
As the monomer, monomer (a2′-2-1) and monomer (a4′-0-12) are used, and the molar ratio (monomer (a2′-2-1): monomer (a4′-0-12)) is The mixture was mixed to 70:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added with respect to the total amount of monomers, respectively, and heated at 75 ° 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 A1-3 having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 85%. . This resin A1-3 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A1-4]
As the monomer, monomer (a2′-2-1) and monomer (a4′-2-3) were used, and the molar ratio (monomer (a2′-2-1): monomer (a4′-2-3)) was The mixture was mixed to 70:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added with respect to the total amount of monomers, respectively, and heated at 75 ° 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 A1-4 having a weight average molecular weight of 1.2 × 10 ^{4 in} a yield of 85%. . This resin A1-4 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A1-5]
As the monomer, monomer (a2′-2-1) and monomer (a4′-1-7) were used, and the molar ratio (monomer (a2′-2-1): monomer (a4′-1-7)) was The mixture was mixed to 70:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added with respect to the total amount of monomers, respectively, and heated at 75 ° 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 having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 78%. . This resin A1-5 has the following structural units.

Synthesis Example 6 [Synthesis of Resin A1-6]
As the monomer, monomer (a2′-2-1) and monomer (a4′-3-2) are used, and the molar ratio (monomer (a2′-2-1): monomer (a4′-3-2)) is The mixture was mixed to 70:30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added with respect to the total amount of monomers, respectively, and heated at 75 ° 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 having a weight average molecular weight of 1.0 × 10 ^{4 in} a yield of 75%. . This resin A1-6 has the following structural units.

Synthesis Example 2 [Synthesis of Resin A2-1]
Charge 100 parts of polyvinylphenol (VP-15000; manufactured by Nippon Soda Co., Ltd.) and 400 parts of acetone, then add 46.0 parts of potassium carbonate, 28.3 parts of 2-iodopropane and 4.6 parts of water, and stir. The mixed solution was refluxed for 30 hours. Thereafter, 200 parts of methyl isobutyl ketone was added to the reaction solution, and then 258 parts of 2% oxalic acid water was added and stirred for separation. Further, 258 parts of 2% oxalic acid water was added to the organic layer, and the mixture was stirred and separated two times. The operation of separating and washing by adding 300 parts of methyl isobutyl ketone and 166 parts of ion-exchanged water to the organic layer after the separation was performed 4 times. The organic layer after washing was concentrated, and 300 parts of methyl isobutyl ketone was further added and concentrated again to obtain 448 parts of a methyl isobutyl ketone solution of resin A2-1-1 (solid content 22%).
176 parts of a methyl isobutyl ketone solution of resin A2-1-1, 330 parts of methyl isobutyl ketone and 0.004 part of p-toluenesulfonic acid dihydrate were charged and concentrated until the total amount of the mixed solution was 273 parts. 8.01 parts of ethyl vinyl ether was added dropwise to the concentrated resin solution, and the mixture was stirred for 2.5 hours for reaction. Thereafter, 58.2 parts of ion-exchanged water and 0.005 part of triethylamine were added to the reaction solution, and the mixture was stirred and separated. Subsequently, 58.2 parts of ion-exchanged water was added to the organic layer and liquid separation was performed 4 times. The organic layer after washing was concentrated, 260 parts of propylene glycol monomethyl ether acetate was added, and the mixture was concentrated again to obtain 143 parts of a propylene glycol monomethyl ether acetate solution of resin A2-1 (solid content 30%). Resin A2-1 had a weight average molecular weight of 1.70 × 10 ⁴ , an introduction rate of isopropyl group with respect to all structural units was 14.2 mol%, and an introduction rate of ethoxyethyl group was 29.7 mol%. Resin A2-1 has the following structural units.

Synthesis Example 3 [Synthesis of Resin A2-2]
40 parts of polyvinylphenol (VP-15000; manufactured by Nippon Soda Co., Ltd.), 240 parts of methyl isobutyl ketone and 0.006 part of p-toluenesulfonic acid dihydrate were added until the total amount of this mixed solution reached 200 parts. Concentrated. To the concentrated resin solution, 10.55 parts of isobutyl vinyl ether was added dropwise and stirred for 2.5 hours. Thereafter, the mixture was diluted with 80 parts of methyl isobutyl ketone, 120 parts of ion-exchanged water and 0.005 part of triethylamine were added to the solution, stirred and separated. Subsequently, the operation of adding 120 parts of ion-exchanged water to the organic layer and separating the liquid was performed 4 times. The organic layer after washing was concentrated, added with 392 parts of propylene glycol monomethyl ether acetate, and concentrated again to obtain 157 parts of propylene glycol monomethyl ether acetate solution of resin A2-2 (solid content 31%). The weight average molecular weight of Resin A2-2 was 2.00 × 10 ⁴ , and the introduction ratio of isobutoxyethyl groups with respect to all the structural units was 27.2 mol%. Resin A2-2 has the following structural units.

Synthesis Example 4 [Synthesis of Resin AX-1]
As the monomer, monomer (a1-1-2), monomer (a2′-2-1), and monomer (a4′-0-2) were used, and the molar ratio (monomer (a2′-2-1): monomer ( a4′-0-2)) was mixed to 20:65:15, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 0.9 mol% and 2.7 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and about 5 at 75 ° C. Heated for 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 AX-1 having a weight average molecular weight of 1.6 × 10 ^{4 in} a yield of 84%. . This resin AX-1 has the following structural units.

Synthesis Example 5 [Synthesis of Resin AX-2]
As the monomer, monomer (a1-x), monomer (a4′-0-x) and monomer (a5-x) are used, and the molar ratio thereof (monomer (a1-x): monomer (a4′-0-x)): The monomer (a5-x)) was mixed so as to be 40:20:40, and 1.5 mass times of isopropanol of the total monomer amount was added to obtain a solution. To this solution, 5 mol% of dimethyl 2,2-azobis (2-methylpropionate) as an initiator was added with respect to the total monomer amount, and the mixture was heated to reflux for 12 hours. After cooling, the reaction solution was poured into a large amount of methanol, and the polymer was precipitated and filtered. The obtained filtrate and 1.2 mol times 4-dimethylaminopyridine of the monomer (a5-x) were added to methanol and heated to reflux for 20 hours. After cooling, the reaction solution was neutralized with glacial acetic acid, poured into a large amount of water to precipitate, and this resin was filtered to obtain resin AX-2 having a weight average molecular weight of 1.0 × 10 ^{4 in} a yield of 55%. It was. This resin AX-2 has the following structural units.

<Preparation of resist composition>
In this example and the like, the components contained in the resist composition other than the resin are as follows.

<Acid generator (B)>
B1: Bis (tert-butanesulfonyl) diazomethane; (WPAG-170; manufactured by Wako Pure Chemical Industries, Ltd.)

  B2: Diphenyltolylsulfonium p-toluenesulfonate (manufactured by Wako Pure Chemical Industries, Ltd.)

<Basic compound: Quencher>
C1: Synthesis according to the examples of JP2012-197261A

  A mixture obtained by mixing and dissolving the components shown in Table 1 together with the following solvent and other components was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Other ingredients>
PPG1000 (polypropylene glycol) 0.135 parts <solvent>
Propylene glycol monomethyl ether acetate 180 parts Propylene glycol monomethyl ether 20 parts γ-butyrolactone 1 part

(Manufacture of positive resist pattern)
An organic antireflective coating composition (DUV-42P; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer, and baked at 205 ° C. for 60 seconds to form an organic reflective film having a thickness of 60 nm on the wafer. A prevention film was formed. Next, on this organic antireflection film, the resist composition described in Table 1 was applied (spin coated) so that the film thickness after drying was 280 nm.
Thereafter, the composition layer was formed by prebaking on a direct hot plate for 60 seconds at the temperature shown in the column “PB” in Table 1. A wafer with the composition layer thus formed was applied to a KrF excimer laser stepper (NSR-2205EX12B; manufactured by Nikon Corporation), NA 0.55, 2/3 Ann. The exposure amount was changed stepwise and exposure was performed through a mask having a line-and-space pattern of 100 to 500 nm with an interval of 10 nm.
After exposure, perform post-exposure baking for 60 seconds at the temperature shown in the column of “PEB” in Table 1 on the hot plate, and then perform paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution. Thus, a resist pattern was obtained.
The exposure amount at which the 300 nm dark space (isolated space line) width was 300 nm was defined as the dark effective sensitivity.
The exposure amount at which an isolated line pattern width of 300 nm becomes 300 nm was defined as the effective sensitivity of bright.

(Positive resist pattern shape evaluation)
The cross-sectional shape of the obtained resist pattern was observed with a scanning electron microscope. For each effective sensitivity, Table 200 shows that the shape of the 200 nm space pattern missing portion and the isolated line pattern portion is rectangular, and the shape that is not rectangular (top clogged, T-top shape) is x.

<Preparation of resist composition>
A mixture obtained by mixing and dissolving the components shown in Table 3 together with the following solvents and other components was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Other ingredients>
PPG1000 (polypropylene glycol) 0.135 parts Nicalac MX-270 (manufactured by Sanwa Chemical Co., Ltd.) 1.62 parts <solvent>
Propylene glycol monomethyl ether acetate 96 parts Propylene glycol monomethyl ether 3 parts γ-butyrolactone 3 parts

(Manufacture of negative resist patterns)
The resist composition shown in Table 3 was applied to a silicon wafer so that the film thickness after drying was 705 nm (spin coating).
Thereafter, the composition layer was formed by pre-baking on a direct hot plate for 60 seconds at the temperature shown in the column of “PB” in Table 3. A KrF excimer laser stepper [NSR-2205EX12B; manufactured by Nikon Corporation, NA 0.55, 2/3 Ann. The exposure amount was changed stepwise and exposure was performed through a mask having a line-and-space pattern of 100 to 500 nm with an interval of 10 nm.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature indicated in the column “PEB” in Table 3. 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.
The exposure amount at which the 300 nm dark space (isolated space line) width was 300 nm was defined as the dark effective sensitivity.

(Shape evaluation of negative resist pattern)
The cross-sectional shape of the obtained resist pattern was observed with a scanning electron microscope. The effective sensitivity is shown in Table 4 when the shape of the missing portion of the 180 nm space pattern is a rectangle, and when it is not a rectangle (upper clogging) is indicated by x.

  The resist composition containing the resin of the present invention can produce a resist pattern having a good pattern shape.

Claims (4)

(A1) A resin containing a structural unit represented by the formula (a2-2) and a structural unit represented by the formula (a4) and having no acid labile group.

[In the formula (a2-2),
R ^a40 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a41 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
mb represents the integer of 0-4. When mb is an integer greater than or equal to 2, several ^Ra41 may mutually be same or different. ]

[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 24 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ] The structural unit represented by the formula (a4) is a structural unit represented by the formula (a4-0), a structural unit represented by the formula (a4-1), or a structural unit represented by the formula (a4-2). And the resin according to claim 1, which is at least one selected from the group consisting of structural units represented by formula (a4-3).

[In the formula (a4-0),
R ^f1 represents a hydrogen atom or a methyl group.
R ^f2 represents a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms. ]

[In the formula (a4-1),
R ^f3 represents a hydrogen atom or a methyl group.
L ³ represents 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.
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 bivalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f13 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. ]   A resist composition comprising the resin according to claim 1, a resin having an acid labile group, and an acid generator. (1) The process of apply | coating the resist composition of Claim 3 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.