JP6205156B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

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

JP 2010-197413 A

  Conventional resist compositions may not always satisfy the CD uniformity (CDU) at the time of producing a resist pattern, or defects may occur.

The present invention includes the following inventions.
[1] (A1) a resin having a structural unit represented by formula (I),
(A2) a resin having an acid labile group,
(B1) A resist composition containing an acid generator represented by the formula (II).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]
[In the formula (II),
R ^II1 and R ^II2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^II1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _T —CO—O—CH ₂ — (CH ₂ ) _u — *, and the methylene group contained in the alkanediyl group and — (CH ₂ ) _u — may be replaced by an oxygen atom. t represents an integer of 1 to 12. u represents an integer of 0 to 12. * Represents a bond with Y.
Y ^II1 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methylene group contained in the alicyclic hydrocarbon group is an oxygen atom, a sulfonyl group or a carbonyl group. It may be replaced with.
^{R II3, R II4, R II5} , R II6 and R ^II7 each independently represent a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, having 2 to 7 carbon atoms An alkoxycarbonyloxy group or an acyloxy group having 2 to 12 carbon atoms is represented.
The methylene group contained in the ring containing S of the cation may be replaced with an oxygen atom or a carbonyl group.
n represents an integer of 1 to 3.
s represents an integer of 0 to 3.
R ^II8 represents an alkyl group having 1 to 6 carbon atoms. When s is 2 or more, a plurality of R ^II8 are the same or different. ]
[2] The resist composition according to [1], further comprising an acid generator represented by the formula (III).
[In the formula (III),
R ^III1 and R ^III2 are each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^III1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y ^III1 represents an ^optionally substituted alkyl group having 1 to 18 carbon atoms or an ^optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the alkyl group and The methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Z ⁺ represents an organic cation. ]
[3] The resist composition according to [1] or [2], wherein R ² is a fluorinated alkyl group having 1 to 6 carbon atoms.
[4] The resist composition according to [1] to [3], wherein A ¹ is a methylene group.
[5] The resist composition according to any one of [1] to [4], wherein L ^II1 is a single bond or a methylene group.
[6] The resist composition according to any one of [1] to [5], wherein Z ⁺ is a triarylsulfonium cation.
[7] The resist composition according to any one of [1] to [6], further containing a solvent.
[8] (1) A step of applying the resist composition according to any one of [1] to [7] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a resist pattern with excellent CD uniformity (CDU) and few defects can be obtained.

In this specification, "(meth) acrylic monomer" means at least one monomer having the structure of "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " 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.

<Resist composition>
The resist composition of the present invention comprises:
(A) resin (hereinafter sometimes referred to as “resin (A)”), and
(B1) Contains an acid generator represented by formula (II).
Here, the resin (A) includes the following resins.
(A1) Resin having a structural unit represented by the formula (I) (hereinafter sometimes referred to as “resin (A1)”) and (A2) Resin having an acid labile group (hereinafter referred to as “resin (A2)”) There).
The resist composition of the present invention preferably further contains an acid generator (III).
The resist composition of the present invention further includes a solvent (E) (hereinafter sometimes referred to as “solvent (E)”) and / or a basic compound (hereinafter sometimes referred to as “basic compound (C)”). It is preferable to contain.

<Resin (A)>
The resin (A) contained in the resist composition of the present invention includes the resins (A1) and (A2) described above, and includes resins other than the resins (A1) and (A2) as described later. May be.

<Resin (A1)>
The resin (A1) has a structural unit represented by the above-described formula (I) (hereinafter sometimes referred to as “structural unit (I)”).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]

The hydrocarbon group for R ² includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type, and a combination thereof. As the aliphatic hydrocarbon group, an alkyl group or an alicyclic hydrocarbon group is preferable.
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 alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a methyl group. Examples thereof include cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. Group, methylnorbornyl group and isobornyl group.

Examples of the hydrocarbon group having a fluorine atom include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include difluoromethyl group, trifluoromethyl group, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2 , 2,2-trifluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, 1,1,1,2,2- Pentafluoropropyl group, perfluoropropyl group, 1,1,1,2,2,3,3-peptafluorobutyl group, perfluorobutyl group, 1,1,1,2,2,3,3,4,4 -Fluoroalkyl groups such as nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group and perfluorooctyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

In the formula (I), A ¹ is preferably — (CH ₂ ) _m1 —, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.
R ² is preferably a fluorinated alkyl group, more preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

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

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

The structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).
[In formula (I ′), R ¹ , A ¹ and R ² represent the same meaning as described above. ]

Compound (I ′) can be produced, for example, by the following reaction.
[Wherein R ¹ , A ¹ and R ² represent the same meaning as described above. ]
It is preferable to react the compound represented by the formula (I′-1) and the compound represented by the formula (I′-2) in a solvent in the presence of a catalyst. As the solvent, dimethylformamide or the like is used. As the catalyst, potassium carbonate, potassium iodide and the like are used.

The compound represented by the formula (I′-1) is preferably a compound (commercially available) that can be easily obtained from the market. Such commercial products include methacrylic acid.
The compound represented by the formula (I′-2) is produced, for example, by reacting the compound represented by the formula (I′-3) with the compound represented by the formula (I′-4). Can do. This reaction is carried out in a solvent in the presence of a base catalyst. Tetrahydrofuran or the like is used as a solvent used in this reaction. As the base catalyst, pyridine or the like is used.
As the compound represented by the formula (I′-3), an appropriate compound can be used depending on the type of A ¹ .
The compound represented by the formula (I′-2) when A ¹ is a methylene group is produced by using, for example, chloroacetyl chloride as the compound represented by the formula (I′-3). Can do. This chloroacetyl chloride is readily available from the market.
As the compound represented by the formula (I′-4), an appropriate alcohol can be used depending on the type of R ² .
The compound represented by the formula (I′-2), in which R ² is an aliphatic hydrocarbon group substituted with a fluorine atom, includes, for example, 2, 2, as the compound represented by the formula (I′-4) It can be produced by using 3,3,4,4,4-heptafluoro-1-butanol or the like. This 2,2,3,3,4,4,4-heptafluoro-1-butanol is readily available from the market.

The resin (A1) may have a structural unit different from the structural unit (I).
The structural unit different from the structural unit (I) includes a structural unit derived from the acid labile monomer (a1) described later, a structural unit derived from the acid stable monomer (a4), and a structural unit represented by the formula (IIIA) And structural units derived from known monomers used in the art. A structural unit represented by the formula (IIIA) is preferable.
[In the formula (IIIA),
R ¹¹ represents a hydrogen atom or a methyl group.
Ring ^{W 2} represents a hydrocarbon ring having 6 to 10 carbon atoms.
A ¹² represents —O—, ^* —CO—O—, or ^* —O—CO— ( ^* represents a bond to ring W ¹ ).
R ¹² represents a C 1-6 alkyl group having a fluorine atom. ]

Examples of the hydrocarbon ring of ring W ² include an alicyclic hydrocarbon ring, and a saturated alicyclic hydrocarbon ring is preferable.
Examples of the saturated alicyclic hydrocarbon ring include the following rings.

Ring W ² is preferably an adamantane ring or a cyclohexane ring, and more preferably an adamantane ring.
The alkyl group having 1 to 6 carbon atoms and having a fluorine atom in R ^12, for example, the following groups.

As the structural unit represented by the formula (IIIA), structural units represented by the following are preferable.
In the structural unit, a structural unit in which a methyl group corresponding to R ¹¹ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (IIIA).
Among these, a structural unit represented by the formula (IIIA-1) or a structural unit in which a methyl group corresponding to R ¹¹ in the structural unit is replaced with a hydrogen atom is particularly preferable.

The content ratio of the structural unit (I) in the resin (A1) is more preferably in the range of 5 to 100 mol%, further preferably in the range of 10 to 100 mol%, based on all the structural units of the resin (A1) The range of 50 to 100 mol% is more preferable, and the range of 80 to 100 mol% is particularly preferable.
When the resin (A1) has the structural unit (IIIA), the content ratio of the structural unit (IIIA) in the resin (A1) is in the range of 1 to 95 mol% with respect to all the structural units of the resin (A1). The range of 2 to 80 mol% is more preferable, the range of 5 to 70 mol% is more preferable, the range of 5 to 50 mol% is particularly preferable, and the range of 5 to 30 mol% is particularly preferable. When the structural unit (IIIA) is included and the content ratio is within the above range, a resist pattern having excellent CD uniformity (CDU) and few defects can be manufactured.
Resin (A1) having structural units (I) and / or (IIIA) in such a content ratio is compound (I ′), structural unit (IIIA) relative to the total molar amount of all monomers used in the production of resin (A1). It can be produced by adjusting the molar amount of the monomer used for deriving.
Each structural unit (I) and / or (IIIA) constituting the resin (A1) may be used alone or in combination of two or more, and optionally, an acid stable monomer (a1), an acid stable monomer (described later) It can be produced by a known polymerization method (for example, radical polymerization method) by combining a2), an acid stable monomer (a3), and one or more monomers known in the art.
The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 7,000 or more, more preferably 10,000 or more), 80,000 or less (more preferably 50,000 or less, further preferably Is 30,000 or less). A weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.

<Resin (A2)>
The resin (A2) is a resin having an acid labile group. The resin having an acid labile group is derived from one or more monomers having an acid labile group (hereinafter sometimes referred to as “acid labile monomer (a1)”).
In addition, the resin (A2) is a structural unit derived from a monomer having no acid labile group, which will be described later (hereinafter sometimes referred to as “acid stable monomer”), as long as it has the acid labile group described above. The structural unit derived from a known monomer, the structural unit represented by the structural unit (I) and the formula (IIIA) described above may be included.
The resin (A2) may be a resin different from the resin (A1), or has a structural unit represented by the formula (I) and a structural unit represented by the formula (IIIA). Further, it may be a resin having an acid labile group.

<Acid labile monomer (a1)>
The acid labile monomer (a1) is a monomer having at least an acid labile group. Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

In Expression (1), R ^a1 ~R ^a3 each independently represent a cycloaliphatic hydrocarbon radical of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms, R ^a1 and R ^a2 are each Bonding to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]
[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-. * Represents a bond. ]

^Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group 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 cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond).
Examples of the alicyclic hydrocarbon group substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
In Formula (1), the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

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

Examples of the acid labile group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), groups in which R ^{a1 to} R ^a3 are alkyl groups, preferably tert-butoxycarbonyl). Group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom 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 for R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include a divalent aliphatic hydrocarbon group.
In the formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

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

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If a resin obtained by polymerizing an acid labile monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used, the resolution of the resist pattern can be improved.

  The (meth) acrylic monomer having an acid labile group and an alicyclic hydrocarbon group is preferably a monomer for deriving a structural unit represented by formula (a1-1) or represented by formula (a1-2). And a monomer that induces a structural unit. These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are represented by the structural unit (a1-1) and the structural unit (a1-2), respectively. The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 ′ represents an integer of 0 to 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—, 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 for R ^a6 and R ^a7 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 alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 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 10 or less including the carbon number of the alkyl group. Specific examples include the same groups as the alicyclic hydrocarbon groups represented by R ^{a1 to} R ^{a3 in} the formula (1).
m1 ′ is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Monomers respectively represented by formula (a1-1-1) to formula (a1-1-8) are preferred, and monomers represented by formula (a1-1-1) to formula (a1-1-4) are preferred. More preferred.

Examples of the monomer (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Examples include acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate. Monomers respectively represented by formula (a1-2-1) to formula (a1-2-12) are preferred, and are represented by formula (a1-2-3), formula (a1-2-4), and formula (a1-2-2). 9) and monomers represented by formula (a1-2-10) are more preferred, and monomers represented by formula (a1-2-3) and formula (a1-2-9) are more preferred.

  When resin (A2) contains structural unit (a1-1) and / or structural unit (a1-2), these total content rates are 10-95 mol normally with respect to all the structural units of resin (A2). %, Preferably 15 to 90 mol%, more preferably 20 to 85 mol%.

As another acid labile monomer (a1), for example, a monomer represented by formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (hereinafter referred to as “monomer (a1-5)”) May be used).
In formula (a1-5),
R ³¹ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^{1 to} L ³ represent an oxygen atom, a sulfur atom, or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O—. Here, k1 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxy group or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ¹ is preferably an oxygen atom.
One of L ² and L ³ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ¹ is preferably a single bond or —CH ₂ —CO—O—.

Examples of the monomer (a1-5) include the following monomers.

  When the resin (A2) has a structural unit derived from the monomer (a1-5), the content thereof is preferably in the range of 1 to 50 mol% with respect to all the structural units of the resin (A2). The range of 45 mol% is more preferable, and the range of 5 to 40 mol% is more preferable.

<Acid stable monomer>
As an acid stable monomer, Preferably, the monomer which has a hydroxyl group or a lactone ring is mentioned. Acid-stable monomer having a hydroxy group (hereinafter sometimes referred to as “acid-stable monomer having a hydroxy group (a2)”) or acid-stable monomer having a lactone ring (hereinafter referred to as “acid-stable monomer having a lactone ring (a3)”) If a resin having a structural unit derived from (sometimes) is used, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group (a2)>
When the resist composition is used for KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV light, the acid-stable monomer (a2) having a hydroxy group is preferably a phenolic hydroxy which is a hydroxystyrene. An acid-stable monomer having a group is used. When using short-wavelength ArF excimer laser exposure (193 nm) or the like, the acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer having a hydroxyadamantyl group represented by the formula (a2-1). use. The acid-stable monomer (a2) having a hydroxy group may be used alone or in combination of two or more.

Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).
In formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As an acid stable monomer (a2-1) which has a hydroxyadamantyl group, the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Monomers respectively represented by formula (a2-1-1) to formula (a2-1-6) are preferred, and monomers represented by formula (a2-1-1) to formula (a2-1-4) are preferred. More preferred is a monomer represented by formula (a2-1-1) or formula (a2-1-3).

  When the resin (A2) contains a structural unit derived from the monomer represented by the formula (a2-1), the content is usually 1 to 45 mol% with respect to all the structural units of the resin (A2). , Preferably it is 1-40 mol%, More preferably, it is 2-35 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a monocyclic lactone ring and other rings The condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring or a condensed ring of γ-butyrolactone ring and another ring is preferable.

  The acid-stable monomer (a3) having a lactone ring is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These 1 type may be used independently and may use 2 or more types together.

In formula (a3-1) to formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or ^* —O— (CH ₂ ) _k3 —CO—O—.
k3 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an alkyl group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an alkyl group having 1 to 4 carbon atoms.
q1 and r1 each independently represents an integer of 0 to 3. When p1 is 2 or more, a plurality of R ^a21 are the same or different, when q1 is 2 or more, a plurality of R ^a22 are the same or different, and when r1 is 2 or more, a plurality of R ^a23 are the same or different Different.

^Examples of the alkyl group represented by R ^{a21 to} R ^a23 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, and a sec-butyl group.

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are preferably each independently —O— or ^* —O— (CH ₂ ) _k3 —CO—O—, More preferably, it is -O-. k3 is preferably an integer of 1 to 4, more preferably 1.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

  Examples of the acid-stable monomer (a3) having a lactone ring include monomers described in JP 2010-204646 A. Formula (a3-1-1) to Formula (a3-1-4), Formula (a3-2-1) to Formula (a3-2-4), Formula (a3-3-1) to Formula (a3-3) -4) is preferable, and each represented by the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-3), or the formula (a3-2-4). The monomer represented by Formula (a3-1-1) or Formula (a3-2-3) is more preferable.

  When the resin (A2) includes a structural unit derived from the acid-stable monomer (a3) having a lactone ring, the total content is usually 5 to 70 mol% with respect to all the structural units of the resin (A2). , Preferably it is 10-65 mol%, More preferably, it is 10-60 mol%.

When the resin (A2) is a copolymer of an acid labile monomer (a1) and an acid stable monomer, the structural unit derived from the acid labile monomer (a1) is based on 100 mol% of all structural units. Preferably it is 10-80 mol%, More preferably, it is 20-60 mol%.
The content of the structural unit derived from the monomer having an adamantyl group (particularly the structural unit (a1-1)) is preferably 15 mol% or more based on the total of the structural units derived from the acid labile monomer (a1). is there. When the ratio of the structural unit derived from the monomer having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

  The resin (A2) is preferably a copolymer of an acid labile monomer (a1) and an acid stable monomer. In this copolymer, the acid labile monomer (a1) is more preferably at least one of a monomer (a1-1) having an adamantyl group and a monomer (a1-2) (preferably the monomer having a cyclohexyl group or a cyclopentyl group). One type, more preferably monomer (a1-1). The acid stable monomer is preferably an acid stable monomer (a2) having a hydroxy group and / or an acid stable monomer (a3) having a lactone ring. The acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer (a2-1) having a hydroxyadamantyl group, and the acid-stable monomer (a3) having a lactone ring is more preferably a γ-butyrolactone ring. The acid-stable monomer (a3-1) and the acid-stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring.

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, further preferably 15,000 or less).
Resin (A1) and resin (A2) in resin (A) are, for example, 0.01: 10 to 5:10, preferably 0.05: 10 to 3:10, more preferably 0.1: 10. It is preferable that it is contained at 2:10, particularly preferably 0.2: 10 to 1:10 (mass ratio).

<Resin other than resin (A1) and (A2)>
The resin (A) of the resist composition of the present invention is derived from resins other than the resins (A1) and (A2) described above, for example, structural units derived from the acid labile monomer (a1) described above, and acid stable monomers. In addition to the structural unit, a resin composed of a structural unit derived from a known monomer used in this 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% by mass or less in the solid content of the resist composition. In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the content of the resin (A) relative thereto can be measured, for example, by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (II)>
The acid generator (II) contained in the resist composition of the present invention contains a salt represented by the formula (II).
[In the formula (II),
R ^II1 and R ^II2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^II1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _T —CO—O—CH ₂ — (CH ₂ ) _u — *, and the methylene group contained in the alkanediyl group and — (CH ₂ ) _u — may be replaced by an oxygen atom. t represents an integer of 1 to 12. u represents an integer of 0 to 12. * Represents a bond with Y.
Y ^II1 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methylene group contained in the alicyclic hydrocarbon group is an oxygen atom, a sulfonyl group or a carbonyl group. It may be replaced with.
^{R II3, R II4, R II5} , R II6 and R ^II7 each independently represent a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, having 2 to 7 carbon atoms An alkoxycarbonyloxy group or an acyloxy group having 2 to 12 carbon atoms is represented.
The methylene group contained in the ring containing S of the cation may be replaced with an oxygen atom or a carbonyl group.
r represents an integer of 1 to 3.
R ^II8 represents an alkyl group having 1 to 6 carbon atoms.
s represents an integer of 0 to 3, and when s is 2 or more, a plurality of R ^II8 are the same or different. ]
In the formula (II), a side having a positive charge may be referred to as an “organic cation”, and a side having a negative charge may be referred to as a “sulfonate anion”.

Examples of the perfluoroalkyl group of R ^II1 and R ^II2 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. And a perfluorohexyl group.
In the formula (II), R ^II1 and R ^II2 are each independently preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.

^Examples of the alkanediyl group of L ^II1 include a linear alkanediyl group or a branched alkanediyl group.
Examples of linear alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group. And hexane-1,6-diyl group.
Examples of the branched alkanediyl group include a linear alkanediyl group, an alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a sec-butyl group). A branched alkanediyl group having a side chain such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1, 2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and the like can be mentioned.
The group a methylene group contained in the alkanediyl group is replaced with an oxygen _{atom, -CH 2 -O -, - CH} 2 -CH 2 -O -, - CH 2 -CH 2 -CH 2 -O -, - CH ₂ -CH ₂ -O-CH ₂ - is like, among _others, -CH 2 _-CH 2 -O- are preferred.

Examples of the divalent alicyclic hydrocarbon group represented by L ^II1 include cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1, Examples include cycloalkanediyl groups such as 2-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,2-diyl group, and cyclooctane-1,5-diyl group.

Of L ^II1 _{- (CH} 2) a t -CO-O- * _{is, -CH 2 -CO-O - *} , - (CH 2) 2 -CO-O - *, - (CH 2) 3 -CO- O— *, — (CH ₂ ) ₄ —CO—O— *, — (CH ₂ ) ₆ —CO—O— *, — (CH ₂ ) ₈ —CO—O— *, etc. CH ₂ —CO—O— * and — (CH ₂ ) ₂ —CO—O— * are preferred.

Of ^{_{L II1 - (CH 2) t}} -CO-O-CH 2 - (CH 2) u - The _{*, -CH 2 -CO-O-} CH 2 - *, - CH 2 -CO-O-CH 2 _{-CH 2 - *, - CH 2} -CO-O-CH 2 - (CH 2) 2 - *, - CH 2 -CO-O-CH 2 -CH 2 -O - *, - CH 2 -CO-O _{-CH 2 -CH 2 -O-CH 2} - * , and the like.
Among these, ^LII1 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, and more preferably a single bond or a methylene group.

Examples of the alicyclic hydrocarbon group represented by Y ^II1 include monocyclic or polycyclic cycloalkyl groups represented by the following formulas (Y1) to (Y11). In addition to cycloalkyl groups having carbon atoms only as ring atoms, groups in which an alkyl group having 1 to 12 carbon atoms is bonded to carbon atoms of the ring atoms, for example, the following formulas (Y27) to (Y29): ) Is also a cycloalkyl group. The alicyclic hydrocarbon group is preferably a cycloalkyl group having 3 to 12 carbon atoms.
Examples of the substituent that may be substituted with this alicyclic hydrocarbon group include, for example, a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, and a 6 to 18 carbon atoms. An aromatic hydrocarbon group, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or a group represented by — (CH ₂ ) _j2 —O—CO—R ⁱ¹ (wherein R ⁱ¹ represents an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 being 0 to 4 Represents an integer).
In addition, the aromatic hydrocarbon group having 6 to 18 carbon atoms and the aralkyl group having 7 to 21 carbon atoms, which are substituents of the alicyclic hydrocarbon group represented by Y ^II1 , further include, for example, an alkyl having 1 to 8 carbon atoms. It may be substituted with a group, a halogen atom or a hydroxy group.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
As the alkoxy group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group, heptoxy group, octoxy group , 2-ethylhexoxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-methoxyphenyl group, p- Examples include an adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, an anthryl group, a phenanthryl group, a 2,6-diethylphenyl group, and an aryl group such as 2-methyl-6-ethylphenyl.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group and the like.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of the aliphatic hydrocarbon group for R ⁱ¹ include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group for R ⁱ¹ may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and methylnorbornyl group, and groups shown below.
Examples of the aromatic hydrocarbon group for R ⁱ¹ are the same as those described above.

Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group of Y ^II1 is replaced by an oxygen atom, a sulfonyl group (—SO ₂ —) or a carbonyl group include, for example, a cyclic ether group (included in the alicyclic hydrocarbon group). A group in which one or two of the methylene groups are replaced by oxygen atoms), a cyclic ketone group (a group in which one or two of the methylene groups contained in the alicyclic hydrocarbon group are replaced by carbonyl groups), a sultone ring group ( Of the methylene groups contained in the alicyclic hydrocarbon group, two adjacent methylene groups are groups in which the oxygen atom and the sulfonyl group are replaced, respectively, and the lactone ring group (the methylene group contained in the alicyclic hydrocarbon group). Among these, groups represented by the following formulas (Y12) to (Y26) include, for example, groups in which two adjacent methylene groups are each replaced by an oxygen atom and a carbonyl group. That.

In the above formula, * represents a bond with L ¹ .
Y ^II1 is preferably a group represented by any one of formula (Y1) to formula (Y19), formula (Y27) to formula (Y29), and is represented by formula (Y11), formula (Y14), formula (Y Y15), a formula (Y19), a formula (Y27), a formula (Y28) or a group represented by formula (Y29) is more preferred, and a group represented by formula (Y11) or formula (Y14) is more preferred.

Examples of the alicyclic hydrocarbon group having a hydroxy group include the following.

Examples of the alicyclic hydrocarbon group having an aromatic hydrocarbon group having 6 to 18 carbon atoms include the following.

Examples of the alicyclic hydrocarbon group having a group represented by — (CH ₂ ) _j2 —O—CO—R ⁱ¹ include the following.

Y ^II1 is more preferably an adamantyl group which may have a substituent, and further preferably an adamantyl group or a hydroxyadamantyl group.

Examples of the sulfonate anion include sulfonate anions represented by any of the following formulas (b1-1-1) to (b1-1-9). R ⁱ² is a group formed by bonding to a carbon atom of the ring atom of the alicyclic hydrocarbon group represented by Y ^II1 , preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group. R ⁱ³ is a substituent of an aromatic hydrocarbon group that is a substituent of the alicyclic hydrocarbon group represented by Y ^II1 , preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

As the sulfonate anion, one in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms and Y ^II1 is an unsubstituted saturated cyclic hydrocarbon group is preferable. Examples of such sulfonate anions include the following.

As a sulfonate anion where L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and Y ^II1 is an alicyclic group having a group represented by — (CH ₂ ) _j2 —O—CO—R ^i1. For example, the following may be mentioned.

Examples of the sulfonate anion in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms and Y ^II1 is an alicyclic hydrocarbon group having a hydroxy group include the following.

A sulfonate anion in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and Y ^II1 is an alicyclic hydrocarbon group having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having an aralkyl group. For example, the following may be mentioned.

Examples of the sulfonate anion in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms and Y ^II1 is the cyclic ether group include the following.

Examples of the sulfonate anion in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms and Y ^II1 is the lactone ring group include the following.

Examples of the sulfonate anion in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms and Y ^II1 is the cyclic ketone group include the following.

Examples of the sulfonate anion in which L ^II1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms and Y ^II1 is the sultone ring group include the following.

L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is unsubstituted alicyclic carbonization. Examples of the sulfonate anion that is a hydrogen group include the following.

L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is — (CH ₂ ) _j2 —. Examples of the sulfonate anion that is an alicyclic group having a group represented by O—CO—R ⁱ¹ include the following.

L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is an alicyclic group having a hydroxy group. Examples of the sulfonate anion which is a hydrocarbon group include the following.

L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 has an aromatic hydrocarbon group. Examples of the sulfonate anion that is an alicyclic hydrocarbon group include the following.

A ^{sulfone in} which L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is the cyclic ether group. Examples of the acid anion include the following.

A sulfone wherein L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is the lactone ring group. Examples of the acid anion include the following.

A sulfone wherein L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is the cyclic ketone group. Examples of the acid anion include the following.

A sulfone wherein L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is the sultone ring group. Examples of the acid anion include the following.

L ^II1 is — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _t —CO—O—CH ₂ — (CH ₂ ) _u — *, and Y ^II1 is an unsubstituted alicyclic group. Examples of the sulfonate anion which is a hydrocarbon group include the following.

Of the sulfonate anions, the following sulfonate anions are preferred.

^Examples of the alkyl group of R ^{II3 to} R ^II7 include a methyl group, an ethyl group, a propyl group, and a butyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group and a t-butoxycarbonyloxy group.
Examples of the acyloxy group include acetyloxy group and benzyloxy group.
^Examples of the alkyl group of R ^II8 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

Examples of those in which the methylene group contained in the ring containing S of the cation is replaced with an oxygen atom or a carbonyl group include the following.

Examples of the organic cation in the formula (II) include the following cations.

  Examples of the salt represented by the formula (II) include a salt composed of a combination of a sulfonate anion and an organic cation described in the following table.

Of these, the salts shown below are preferred.

The salt represented by the formula (II) can be produced, for example, by reacting the salt represented by the formula (II-a) with the salt represented by the formula (II-b) in a solvent. .
^{(Wherein, R II1, R II2, R} II3, R II4, R II5, R II6, R II7, R II8, L II1, s, r and Y ^II1 are as defined above, respectively.)
Examples of the solvent include chloroform.
The salt represented by the formula (II-b) can be produced, for example, by the method described in JP2008-209917A.

The salt represented by the formula (II-a) is produced by reacting the salt represented by the formula (II-c) with the compound represented by the formula (II-d) in a solvent in the presence of a catalyst. can do.
^{(Wherein, R II3, R II4, R} II5, R II6, R II7, R II8, s and r are as defined above, respectively.)
Examples of the catalyst include copper (II) benzoate.
Examples of the solvent include monochlorobenzene.
Examples of the salt represented by the formula (II-c) include diphenyliodonium benzenesulfonate.
Examples of the compound represented by the formula (II-d) include pentamethylene sulfide, 1,4-thioxan, and tetrahydrothiophene.

As another method, for example, the salt represented by the formula (II) includes, for example, a salt represented by the formula (II-a ′) and a compound represented by the formula (II-b ′) in the presence of a catalyst. It can manufacture by making it react in a solvent.
^{(Wherein, R II1, R II2, R} II3, R II4, R II5, R II6, R II7, R II8, L II1, s, r and Y ^II1 are as defined above, respectively.)
Examples of the catalyst include copper (II) dibenzoate.
Examples of the solvent include monochlorobenzene.
Examples of the compound represented by the formula (II-b ′) include pentamethylene sulfide, 1,4-thioxan, tetrahydrothiophene and the like.

As the salt represented by the formula (II-a ′), for example, the salt represented by the formula (II-c ′) and the salt represented by the formula (II-d ′) are reacted in a solvent. Can be manufactured.
^{(Wherein, R II1, R II2, R} II3, R II4, R II5, R II6, R II7, L II1 and Y ^II1 are as defined above, respectively.)
Examples of the solvent include chloroform and water.
Examples of the salt represented by the formula (II-c ′) include diphenyliodonium chloride.
The salt represented by the formula (II-d ′) can be produced, for example, by the method described in JP2008-209917A.

<Acid generator (III)>
The resist composition of the present invention may further contain an acid generator (III) in addition to the acid generator (II).
The acid generator (III) contained in the resist composition of the present invention contains a salt represented by the formula (III).
[In the formula (III),
R ^III1 and R ^III2 are each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^III1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y ^III1 represents an ^optionally substituted alkyl group having 1 to 18 carbon atoms or an ^optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the alkyl group and The methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group R ^III1 and R ^III2, for example, a trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group, perfluoro-tert- butyl group, perfluoropentyl group And perfluorohexyl group.
In formula (III), R ^III1 and R ^III2 are each independently preferably an fluorine atom or a trifluoromethyl group, more preferably a fluorine atom.

^Examples of the divalent saturated hydrocarbon group of L ^III1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4 A branched alkanediyl group such as a diyl group or 2-methylbutane-1,4-diyl group;
Cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1,2-diyl group, cyclohexane-1,4-diyl group, cyclo A monocyclic divalent alicyclic saturated hydrocarbon group which is a cycloalkanediyl group such as an octane-1,2-diyl group or a cyclooctane-1,5-diyl group;
A polycyclic group such as norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. A bivalent alicyclic saturated hydrocarbon group etc. are mentioned.

^Examples of the group in which the methylene group contained in the saturated hydrocarbon group of L ^III1 is replaced with an oxygen atom or a carbonyl group include formula (b1-1) to formula (b1-7). In addition, Formula (b1-1)-Formula (b1-7) have described the right and left according to Formula (III), and among two bonds represented by *, C (Q ¹ ) It binds to (Q ² ) ^-and binds to -Y ^III1 on the right side. The same applies to specific examples of the following formulas (b1-1) to (b1-7).

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b6 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 15.
L ^b7 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 16.
L ^b9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b10 represents a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 14.
L ^b11 and L ^{b12 each} represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b13 represents a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 12.
L ^b14 and L ^b15 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b16 represents a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 14.
Among them, L ^III1 is preferably any one of formula (b1-1) to formula (b1-4), more preferably formula (b1-1) or formula (b1-2), and still more preferably formula (b1-1). And particularly preferably a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ —.

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

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

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

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

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

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

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

Specific examples when the hydrogen atom contained in the aliphatic saturated hydrocarbon group of L ^III1 is substituted with a fluorine atom or a hydroxy group include the following.

The alkyl group for Y ^III1 is preferably an alkyl group having 1 to 6 carbon atoms.
^Examples of the alicyclic hydrocarbon group represented by Y ^III1 include the groups represented by the formulas (Y1) to (Y11) and the groups represented by the formulas (Y27) to (Y29).
Examples of the substituent for these alkyl group and alicyclic hydrocarbon group include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and a carbon number. An alicyclic hydrocarbon group having 3 to 16 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, Glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or the number of carbon atoms) Represents an aromatic hydrocarbon group of 6 to 18. j2 represents an integer of 0 to 4).
The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group and the like, which are the substituent of Y ^III1 , may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.

  Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.

^Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group of Y ^III1 is replaced by an oxygen atom, a sulfonyl group or a carbonyl group include a cyclic ether structure (a group in which —CH ₂ — is replaced by —O—), An alicyclic hydrocarbon group having an oxo group (a group in which —CH ₂ — is replaced by —CO—) and a sultone ring group (two adjacent —CH ₂ — are each represented by —O— or —SO ₂ —, respectively. A substituted group) or a lactone ring group (a group in which two adjacent —CH ₂ — are replaced by —O— or —CO—, respectively).

In particular, ^examples of the group in which the methylene group contained in the alicyclic hydrocarbon group of Y ^III1 is replaced by an oxygen atom, a sulfonyl group, or a carbonyl group include the groups represented by the above formulas (Y12) to (Y26). It is done.
Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

^Examples of Y ^III1 include the following.

Y ^III1 is preferably an adamantyl group which may have a substituent (for example, a hydroxy group, an oxo group, etc.), more preferably an adamantyl group, an oxoadamantyl group or a hydroxyadamantyl group.

The sulfonate anion in the salt represented by the formula (III) is preferably an anion represented by the formula (III1-1-1) to the formula (III1-1-9). In the following formulae, the definition of the substituent has the same meaning as described above, and the substituents R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt represented by the formula (III) include anions described in JP 2010-204646 A.

Examples of the cation Z ⁺ contained in the acid generator (III) include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.

More preferably, for example, cations represented by the formulas (Z1) to (Z4) may be used.

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

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

P < ¹⁰ > -P < ¹⁵ > represents a hydroxyl group, a C1-C12 aliphatic hydrocarbon group, or a C1-C12 alkoxy group each independently.
E represents -S- or -O-.
i, j, p, r, x and y each independently represents an integer of 0 to 5;
q represents 0 or 1;
v and w each independently represent an integer of 0 to 4.
When i is 2 or more, the plurality of P ⁴ are the same or different from each other. When j is 2 or more, the plurality of P ⁵ are the same or different from each other. When p is 2 or more, the plurality of P ¹⁰ are the same. Or, when r is 2 or more, a plurality of P ¹¹ are the same or different from each other, when v is 2 or more, a plurality of P ¹² are the same or different from each other, and when w is 2 or more, a plurality of P 11 ¹³ are the same or different from each other. When x is 2 or more, the plurality of P ¹⁴ are the same or different from each other, and when y is 2 or more, the plurality of P ¹⁵ are the same or different from each other.

Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl 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, a methylnorbornyl group, and the following groups. * Represents a bond with an adamantane ring or a cyclohexane ring.
Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a 2-alkyladamantan-2-yl group, and a methyl group. A norbornyl group, an isobornyl group, etc. are mentioned.
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.
When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms Groups are preferred.

As an alkoxy group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, an n-hexoxy group, a heptoxy group, an octoxy group , 2-ethylhexoxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

Examples of the ring and the P ^a and P ^b together form a monocyclic, polycyclic, aromatic or non-aromatic, it may be any of the rings of the saturated and unsaturated, sulfur atom In addition, one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —CO— may be further included. This ring includes a 3-membered ring to a 18-membered ring, preferably a 3-membered ring to a 12-membered ring or a 4- to 18-membered ring.
The ring formed by combining P ⁶ and P ⁷ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, and a sulfur atom If it contains one or more, it may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —CO—. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.
The ring formed by combining P ⁸ and P ⁹ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated, and —CH— As long as it contains CO-, it may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, -O-, -S-, -CO-. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.

Examples of the ring formed together with the sulfur atom to which P ⁶ and P ⁷ are bonded include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed with —CH—CO— to which P ⁸ and P ⁹ are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

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

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

The ring formed by combining two selected from P ^{1 to} P ³ may be any of monocyclic, polycyclic, aromatic and non-aromatic rings. As long as it contains the above, it may contain one or more sulfur atoms and / or one or more oxygen atoms.
The P ^{1 to} P ³ aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 19 carbon atoms.
Among them, each of P ^{1 to} P ³ independently represents a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, or P ¹ two selected from to P ³ is represent together -O-, it is preferable to form a ring containing a sulfur atom. z1 to z3 are preferably each independently 0 or 1.

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

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

Specific examples of the cation represented by the formula (Z1) include the following.

Specific examples of the cation represented by the formula (Z2) include the following.

Specific examples of the cation represented by the formula (Z3) include the following.

Specific examples of the cation represented by the formula (Z4) include the following.

  The acid generator (III) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, and preferably a combination of any one of anion (III1-1-1) to anion (III1-1-9) and cation (b2-1-1), and A combination of any one of anions (III1-1-3) to (III1-1-5) and a cation (b2-3) may be mentioned.

  The acid generator (III) preferably includes salts represented by the formulas (III-1) to (III-18), more preferably a formula which is an acid generator containing a triphenylsulfonium cation. (III-1), Formula (III-2), Formula (III-3), Formula (III-6), Formula (III-7), Formula (III-11), Formula (III-12), Formula (III) And salts represented by formula (III-13), formula (III-14) and formula (III-18).

  The acid generator represented by the formula (III) can be produced by a method known in the art.

<Acid generator other than acid generator (II) and acid generator (III)>
The resist composition of the present invention is characterized in that it is contained as an acid generator and an acid generator (III) represented by a single type or a plurality of types of formula (II). ) And an acid generator (III) represented by a known acid generator (hereinafter sometimes referred to as “acid generator (B)”).
The acid generator (B) may be an ionic acid generator or a nonionic generator, but an ionic acid generator is preferred. The ionic acid generator is different from the acid generator of the formula (II) and the acid generator (III) in the cation and the anion constituting the ionic acid generator, the acid generator of the formula (II), and the acid generator A combination of the same cation as the organic cation constituting (III) and a known anion other than the sulfonate anion constituting the acid generator or the acid generator (III) of the formula (II), the formula (II ) Acid generator and / or the same anion as the sulfonate anion constituting the acid generator (III) and a known cation other than the organic cation constituting the acid generator or the acid generator (III) of formula (II) Any of the combinations may be used.

  In the resist composition of the present invention, the total content of the acid generator (II), the acid generator (III) and the acid generator (B) is 100 parts by mass of the resin (A) contained in the resist composition. On the other hand, it is preferably 1 part by mass or more, more preferably 3 parts by mass or more. Moreover, it is 40 mass parts or less with respect to 100 mass parts of resin (A), More preferably, it is 35 mass parts or less.

In particular, the content of the acid generator (II) is preferably 1 part by mass or more and more preferably 3 parts by mass or more with respect to 100 parts by mass of the resin (A) contained in the resist composition. Moreover, Preferably it is 30 mass parts or less, More preferably, it is 25 mass parts or less.
When the acid generator (III) is contained, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass with respect to 100 parts by mass of the resin (A) contained in the resist composition. That's it. Moreover, Preferably it is 30 mass parts or less, More preferably, it is 25 mass parts or less. In this case, acid generator (II): acid generator (III) includes, for example, 5:95 to 95: 5 (mass ratio), and preferably 10:90 to 90:10.

<Solvent (E)>
The content rate of the solvent (E) contained in the resist composition of this invention is 90 mass% or more in a resist composition, for example, Preferably it is 92 mass% or more, More preferably, it is 94 mass% or more, for example, 99.9. It is not more than mass%, preferably not more than 99 mass%. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; 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.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The basic compound (C) is a compound that acts as a quencher.
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1). It is done.

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

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are the same or different. ]

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

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

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represents an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different, and when r3 is 2 or more, the plurality of R ^c19 are When the same or different and s3 is 2 or more, the plurality of R ^c20 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

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

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. Particularly preferred include 2,6-diisopropylaniline.

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

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

  The content of the basic compound (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably based on the solid content of the resist composition. It is about 0.01-1 mass%.

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

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A) containing a resin (A1) and a resin (A2), an acid generator, and a solvent (E), basic compound (C) and other components used as necessary. It can be prepared by mixing (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (E), such as 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) A step of applying the resist composition of the present invention on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

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 to form a composition layer from which the solvent has been removed. The temperature in this case is preferably about 50 to 200 ° C., for example. The pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do.

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example.
The composition layer after heating is usually developed using a developer containing butyl acetate or 2-heptanone using a developing device.

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

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

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

<Application>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly a liquid. It is suitable as a resist composition for immersion exposure and useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The structure of the compound was confirmed by MASS (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).
The composition ratio of the resin (A) (copolymerization ratio of the structural unit derived from each monomer used for the production of the resin (A) to the resin (A)) is the amount of unreacted monomer in the reaction liquid after the polymerization is finished. It measured using the chromatography, and computed by calculating | requiring the monomer amount used for superposition | polymerization from the obtained result. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

Synthesis Example 1: Synthesis of compound represented by formula (H)
25 parts of the compound represented by the formula (H-1), 175 parts of tetrahydrofuran and 11.86 parts of pyridine were charged, stirred at 23 ° C. for 30 minutes, cooled to 5 ° C., and represented by the formula (H-2). 14.82 parts of the above compound was added over 30 minutes. After stirring at 5 ° C. for 1 hour, 340 parts of ethyl acetate, 66 parts of 5% hydrochloric acid and 85 parts of ion-exchanged water were added, followed by liquid separation after stirring. To the collected organic layer, 55 parts of a 10% potassium carbonate aqueous solution was added, and after separation, liquid separation was performed. To the recovered organic layer, 85 parts of ion-exchanged water was added, followed by liquid separation after stirring. This washing operation was performed 5 times. By concentrating the collected organic layer, 28.62 parts of a compound represented by the formula (H-3) was obtained.
10.69 parts of the compound represented by the formula (H-4), 53.47 parts of dimethylformamide, 8.58 parts of potassium carbonate and 1.03 parts of potassium iodide were charged and stirred at 40 ° C. for 1 hour. A mixed solution of 28.62 parts of the compound represented by (H-3) and 57.24 parts of dimethylformamide was added over 30 minutes. After stirring at 40 ° C. for 6 hours, the mixture was cooled to 23 ° C. To the obtained reaction mass, 670 parts of chloroform and 166 parts of a 5% aqueous oxalic acid solution were added, followed by liquid separation after stirring. To the collected organic layer, 265 parts of ion-exchanged water was added, followed by liquid separation after stirring. This washing operation was performed 6 times. After the collected organic layer was concentrated, 7.58 parts of acetonitrile and 26.53 parts of ethyl acetate were added to the resulting concentrated mass, and the mixture was stirred for 3 hours, and then filtered, and expressed by the formula (H). 32.13 parts of compound were obtained.

Synthesis Example 2: Synthesis of salt represented by formula (II-3)

  30.00 parts of a compound represented by the formula (II-3-b) obtained by the method described in JP 2008-209917 A, 35.50 of a salt represented by the formula (II-3-a) Part, 100 parts of chloroform, and 50 parts of ion-exchanged water were stirred at 23 ° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and 30 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes and filtered to give the salt represented by formula (II-3-c) 48. 57 parts were obtained.

20.00 parts of a salt represented by the formula (II-3-c), 2.84 parts of a compound represented by the formula (II-3-d) and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . To the obtained mixed liquid, 0.21 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 1 hour. The resulting reaction solution was concentrated. To the obtained residue, 200 parts of chloroform and 50 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. 50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated. The obtained residue was dissolved in 53.51 parts of acetonitrile and concentrated. Thereafter, 113.05 parts of tert-butyl methyl ether was added and stirred, followed by filtration to obtain 10.47 parts of the salt represented by the formula (II-3).

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

Synthesis Example 3: Synthesis of salt represented by formula (II-7)

  11.26 parts of a salt represented by the formula (II-7-a), 10.00 parts of a compound represented by the formula (II-7-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged at 23 ° C. For 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (II-7-c). .75 parts were obtained.

11.71 parts of a salt represented by the formula (II-7-c), 1.70 parts of a compound represented by the formula (II-7-d) and 46.84 parts of monochlorobenzene were charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the obtained residue, stirred, and then filtered to obtain 6.84 parts of the salt represented by the formula (II-7). Got.

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

Synthesis Example 4: Synthesis of salt represented by formula (II-8)

  After adding 1.97 parts of the salt represented by the formula (II-8-a) and 30 parts of chloroform, 0.94 part of diethyl sulfuric acid was added dropwise and stirred at 23 ° C. for 1 hour. The salt 3 represented by the formula (II-8-c) synthesized by the method described in Japanese Patent Application Laid-Open No. 2008-94835 was added to the obtained solution containing the salt represented by the formula (II-8-b). .23 parts and 15 parts of ion-exchanged water were charged and stirred at 23 ° C. for 15 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out, and 10 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer is concentrated, 25.40 parts of tert-butyl methyl ether is added to the obtained residue, and the mixture is stirred at 23 ° C. for 30 minutes, and then filtered, which is represented by the formula (II-8-d) 2.79 parts of salt were obtained.

2.70 parts of a salt represented by the formula (II-8-d), 0.67 part of a compound represented by the formula (II-8-e) and 21.60 parts of monochlorobenzene were charged, and the mixture was stirred at 23 ° C. for 30 minutes. Stir. After adding 0.03 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the resulting reaction solution, 40.50 parts of chloroform, 13.50 parts of ion exchanged water and 0.15 part of 28% aqueous ammonia were added to the resulting residue, and the mixture was stirred at 23 ° C. for 30 minutes. The organic layer was taken out by liquid separation. 13.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to extract the organic layer. This washing operation was repeated three times. After concentration of the obtained organic layer, 36.55 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred and filtered to obtain the salt 1. represented by the formula (II-8). 16 parts were obtained.

MASS (ESI (+) Spectrum): M ⁺ 195.1
MASS (ESI (-) Spectrum): M ^- 323.0

Synthesis Example 5: Synthesis of salt represented by formula (II-9)

  After charging 1.97 parts of the salt represented by the formula (II-9-a) and 30 parts of chloroform, 0.87 parts of diethylsulfuric acid was added dropwise and stirred at 23 ° C. for 1 hour. The solution containing the salt represented by the formula (II-9-b) thus obtained was charged with 3.01 parts of the salt represented by the formula (II-9-c) and 15 parts of ion-exchanged water at 23 ° C. Stir for 15 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out, and 10 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 6 times. The chloroform layer is concentrated, 21.20 parts of tert-butyl methyl ether is added to the obtained residue, and the mixture is stirred at 23 ° C. for 30 minutes, followed by filtration, which is represented by the formula (II-9-d). 2.57 parts of salt were obtained.

2.49 parts of a salt represented by the formula (II-9-d), 0.59 parts of a compound represented by the formula (II-9-e) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.03 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 37.50 parts of chloroform, 12.50 parts of ion-exchanged water and 0.15 part of 28% ammonia water were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes. The organic layer was taken out by liquid separation. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated three times. After concentrating the obtained organic layer, 18.45 parts of tert-butyl methyl ether was added to the obtained residue and stirred, followed by filtration to obtain a salt 1. represented by the formula (II-9). 30 parts were obtained.

MASS (ESI (+) Spectrum): M ⁺ 209.1
MASS (ESI (-) Spectrum): M ^- 323.0

Synthesis Example 6 Synthesis of salt represented by formula (II-10)

  After charging 4.44 parts of the salt represented by the formula (II-10-a) and 90 parts of methanol, 2.11 parts of diethylsulfuric acid was added dropwise and stirred at 23 ° C. for 1 hour. To the obtained solution containing the salt represented by the formula (II-10-b), 7.55 parts of the salt represented by the formula (II-10-c) was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution was concentrated, and 55.28 parts of ion-exchanged water was added to the resulting residue and stirred at 23 ° C. for 30 minutes, and then the supernatant was removed. To the obtained residue, 10 parts of acetonitrile was added, stirred at 23 ° C. for 30 minutes, and then concentrated to obtain 3.57 parts of a salt represented by the formula (II-10-d).

A salt represented by the formula (II-10-d) (3.57 parts), a compound represented by the formula (II-10-e) (0.86 parts) and monochlorobenzene (35.68 parts) were charged, and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.04 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the resulting reaction solution, 44.60 parts of chloroform, 14.87 parts of ion-exchanged water and 0.15 part of 28% aqueous ammonia were added to the resulting residue, and the mixture was stirred at 23 ° C. for 30 minutes. The organic layer was taken out by liquid separation. After adding 14.87 parts of ion-exchanged water to the collected organic layer and stirring at 23 ° C. for 30 minutes, the organic layer was separated by liquid separation. This washing operation was repeated three times. After the obtained organic layer was concentrated, 18.65 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. To the obtained residue, 10 parts of acetonitrile was added, stirred at 23 ° C. for 30 minutes, and concentrated to obtain 0.85 part of a salt represented by the formula (II-10).

MASS (ESI (+) Spectrum): M ⁺ 195.1
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis Example 7: Synthesis of salt represented by formula (II-11)

  After charging 1.97 parts of the salt represented by the formula (II-11-a) and 40 parts of methanol, 0.87 part of diethylsulfuric acid was added dropwise and stirred at 23 ° C. for 1 hour. To the obtained solution containing the salt represented by the formula (II-11-b), 3.13 parts of the salt represented by the formula (II-11-c) was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution is concentrated, and 30.50 parts of ion-exchanged water is added to the resulting residue, followed by stirring at 23 ° C. for 30 minutes, followed by filtration to express the formula (II-11-d). 2.10 parts of the salt was obtained.

A salt represented by formula (II-11-d) (2.01 parts), a compound represented by formula (II-11-e) (0.46 parts) and monochlorobenzene (18.40 parts) were charged, and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.02 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 34.50 parts of chloroform, 11.50 parts of ion-exchanged water and 0.15 part of 28% aqueous ammonia were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes. The organic layer was taken out by liquid separation. 11.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated three times. After concentration of the obtained organic layer, 13.45 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred and then filtered to obtain a salt of the salt represented by the formula (II-11) 0. 77 parts were obtained.

MASS (ESI (+) Spectrum): M ⁺ 209.1
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis Example 8: Synthesis of salt represented by formula (III-5)
50.49 parts of the salt represented by the formula (III-5-a) and 252.44 parts of chloroform are charged into a reactor and stirred at 23 ° C. for 30 minutes, and then represented by the formula (III-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (III-5-c). To the obtained solution containing the salt represented by the formula (III-5-c), 48.80 parts of the salt represented by the formula (III-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of the salt represented by the formula (III-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

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

[Synthesis of Resin A1-1]
Monomer (H) and monomer (I) are used as monomers and mixed so that the molar ratio (monomer (H): monomer (I)) is 90:10. Dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 72 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-1 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 75%. Got in. This resin A1-1 has the following structural units.

[Synthesis of Resin A1-2]
Monomer (H) was used as a monomer, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-2 having a weight average molecular weight of 1.8 × 10 ^{4 in} a yield of 75%. This resin A1-2 has the following structural units.

[Synthesis of Resin A2-1]
Monomer (D), monomer (E), monomer (B), monomer (F), and monomer (C) are in a molar ratio [monomer (D): monomer (E): monomer (B): monomer (F): Monomer (C)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane 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 to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. × obtain a 10 ^third resin A2-1 in 60% yield. This resin A2-1 has the following structural units.

[Synthesis of Resin A2-2]
Monomer (A), monomer (E), monomer (B), monomer (F) and monomer (C) are in a molar ratio [monomer (A): monomer (E): monomer (B): monomer (F): Monomer (C)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane 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 to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.2. × obtain a 10 ^third resin A2-2 in 78% yield. This resin A2-2 has the following structural units.

[Synthesis of Resin A2-3]
Monomer (A), monomer (B) and monomer (C) are mixed so that the molar ratio [monomer (A): monomer (B): monomer (C)] is 50:25:25, , 1.5 mass times dioxane was mixed with respect to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. Then, this was heated at 80 ° C. for about 8 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin is filtered and collected, dissolved again in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and collected three times for reprecipitation. After purification, Resin A2-3 having a weight average molecular weight of about 9.2 × 10 ³ was obtained in a yield of 60%. This resin A2-3 has the following structural units.

[Synthesis of Resin A2-4]
Monomer (D), monomer (L), monomer (B), monomer (C) and monomer (F) are mixed in a molar ratio [monomer (D): monomer (L): monomer (B): monomer (C): The monomer (F)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 8.2. × obtain a 10 ^third resin A2-4 in 68% yield. This resin A2-4 has the following structural units.

[Synthesis of Resin A2-5]
Monomer (D), monomer (L), monomer (K), monomer (C), and monomer (F) are in a molar ratio [monomer (D): monomer (L): monomer (K): monomer (C): The monomer (F)] was mixed to be 35: 15: 3: 27: 20, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.9. × obtain a 10 ^third resin A2-5 in 73% yield. This resin A2-5 has the following structural units.

[Synthesis of Resin A2-6]
Monomer (D), monomer (M), monomer (B), monomer (F) and monomer (C) are mixed in a molar ratio [monomer (D): monomer (M): monomer (B): monomer (F): Monomer (C)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane 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 to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.4. × give 10 ³ of copolymer in 62% yield. This copolymer has the following structural units and is designated as resin A2-6.

[Synthesis of Resin A2-7]
Monomer (D), monomer (L), monomer (K), monomer (F), and monomer (C) are in a molar ratio [monomer (D): monomer (L): monomer (K): monomer (F): Monomer (C)] was mixed so as to be 45: 14: 2.5: 22: 16.5, and propylene glycol monomethyl ether acetate of 1.5 mass times the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate a resin, which was filtered to obtain a copolymer having a weight average molecular weight of 7.8 × 10 ^3. The yield was 73%. This copolymer has the following structural units and is designated as resin A2-7.

[Synthesis of Resin X1]
Monomer (G), monomer (C), and monomer (B) are used as the monomers and mixed so that the molar ratio (monomer (G): monomer (C): monomer (B)) is 35:45:20. Then, 1.5 mass times dioxane of the total monomer amount was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. A × 10 ³ resin X1 (copolymer) was obtained in a yield of 75%. This resin X1 has the following structural units. The molar ratio of each structural unit is structural unit (G): structural unit (C): structural unit (B) = 34.7: 45.4: 19.9.

[Synthesis of Resin X2]
As the monomer, the monomer (J) and the monomer (G) are used and mixed so that the molar ratio (monomer (J): monomer (G)) is 80:20. Dioxane was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.5 mol% and 1.5 mol%, respectively, based on the total monomer amount, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 2.8. A × 10 ⁴ resin X2 (copolymer) was obtained in a yield of 70%. This resin X2 has the following structural units. The molar ratio of each structural unit was structural unit (J): structural unit (G) = 80.2: 19.8.

<Preparation of resist composition>
A mixture obtained by mixing and dissolving the components shown in Table 2 was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1-1, A1-2, A2-1 to A2-7, X1, X2 synthesized by resin synthesis
<Acid generator>
II-3:
II-7:
II-8:
II-9:
II-10:
II-11
III-3: synthesized according to the examples of JP 2010-152341 A
III-5:
B2: synthesized according to examples of WO2008 / 99869 and JP2010-26478
B3: synthesized according to the example of JP-A-2005-221721

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

<Solvent>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.5 parts

<Manufacture of resist pattern>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic antireflective coating having a thickness of 78 nm. Formed. Next, each of the resist compositions in Table 5 was spin-coated on the organic antireflection film so that the film thickness after drying was 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 2 for 60 seconds to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 100 nm) Using a mask for forming a hole diameter of 70 nm), the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was post-exposure baked on a hot plate at a temperature described in the “PEB” column of Table 2 for 60 seconds. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

  In the obtained resist pattern, the exposure amount at which the hole diameter was 55 nm was defined as effective sensitivity.

<Evaluation of CD uniformity (CDU)>
In the effective sensitivity, the hole diameter of the pattern was measured 24 times per hole, and the average value was defined as the average hole diameter of one hole. The average hole diameter is measured for 400 holes formed on the same wafer, and these are used as a population to obtain a standard deviation.
When the standard deviation is less than 1.55 nm,
When the standard deviation is 1.55 nm or more and less than 2.00 nm, “○”,
“X” when the standard deviation is 2.00 nm or more,
Judged as each. The results are shown in Table 3. In Table 3, the numbers in parentheses indicate standard deviation values (nm).

<Defect evaluation>
The resist composition was applied (spin coated) to a 12-inch silicon wafer (substrate) so that the film thickness after drying was 0.15 μm. After coating, the composition layer was formed on the wafer by pre-baking (PB) for 60 seconds at a temperature shown in the PB column of Table 2 on a direct hot plate.
The wafer on which the composition layer was formed in this manner was subjected to water rinsing for 60 seconds using a developing machine [ACT-12; manufactured by Tokyo Electron Ltd.].
Thereafter, the number of defects on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. The results are shown in Table 3.

<Preparation of resist composition>
Each of the components shown below was dissolved in the following solvent in the parts by mass shown in Table 4 and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Manufacture of negative resist pattern>
An organic antireflective coating composition (ARC-29; 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 78 nm on the wafer. A prevention film was formed. Next, on the organic antireflection film, the above resist composition was applied (spin coated) so that the film thickness after drying was 85 nm. After coating, the silicon wafer was pre-baked on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 4 to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 90 nm) Using a mask for forming a hole diameter of 55 nm), the exposure amount was changed stepwise. Note that ultrapure water was used as the immersion medium.
After exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 4. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 45 nm was defined as the effective sensitivity.

<Evaluation of CD uniformity (CDU)>
In terms of effective sensitivity, the hole diameter of the resist pattern was measured 24 times per hole, and the average value was taken as the average hole diameter of one hole. The average hole diameter was measured for 400 holes formed on the same wafer, and the standard deviation was determined using these as the population.
If the standard deviation is less than 2.00 nm,
“X” when the standard deviation is 2.00 nm or more,
Judged as each. The results are shown in Table 5. In Table 5, the numbers in parentheses indicate standard deviation values (nm).

  According to the resist composition of the present invention, it is possible to produce a resist pattern with good CD uniformity (CDU) at the time of producing the resist pattern and few occurrences of defects.

Claims (7)

(A1) a resin having a structural unit represented by formula (I),
(A2) a resin having an acid labile group,
(B1) A resist composition containing an acid generator represented by formula (II) and an acid generator represented by formula (III).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]
[In the formula (II),
R ^II1 and R ^II2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^II1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, — (CH ₂ ) _t —CO—O— * or — (CH ₂ ) _T —CO—O—CH ₂ — (CH ₂ ) _u — *, and the methylene group contained in the alkanediyl group and — (CH ₂ ) _u — may be replaced by an oxygen atom. t represents an integer of 1 to 12. u represents an integer of 0 to 12. * Represents a bond with ^YII1 .
Y ^II1 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methylene group contained in the alicyclic hydrocarbon group is an oxygen atom, a sulfonyl group or a carbonyl group. It may be replaced with.
^{R II3, R II4, R II5} , R II6 and R ^II7 each independently represent a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, having 2 to 7 carbon atoms An alkoxycarbonyloxy group or an acyloxy group having 2 to 12 carbon atoms is represented.
The methylene group contained in the ring containing the sulfonyl cation may be replaced with an oxygen atom or a carbonyl group.
r represents an integer of 1 to 3.
R ^II8 represents an alkyl group having 1 to 6 carbon atoms.
s represents an integer of 0 to 3, and when s is 2 or more, the plurality of R ^II8 are the same or different. ]
[In the formula (III),
R ^III1 and R ^III2 are each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^III1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y ^III1 represents an ^optionally substituted alkyl group having 1 to 18 carbon atoms or an ^optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the alkyl group and The methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Z ⁺ represents an organic cation. ] The resist composition according to claim 1, wherein R ² is a fluorinated alkyl group having 1 to 6 carbon atoms. The resist composition according to claim 1, wherein A ¹ is a methylene group. The resist composition according to claim 1, wherein L ^II1 is a single bond or a methylene group. The resist composition according to claim 1 or 4, wherein Z ⁺ is a triarylsulfonium cation.   Furthermore, the resist composition in any one of Claims 1-5 containing a solvent. (1) The process of apply | coating the resist composition in any one of Claims 1-6 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.