JP6195748B2 - 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 describes a resist composition containing a resin, an acid generator composed of a salt represented by the formula (B1-X), and a quencher composed of 2,6-diisopropylaniline.
Further, it is known that when a resist pattern is formed from a resist composition by photolithography, a positive resist pattern is obtained when developed with an alkaline developer, and a negative resist pattern is obtained when developed with an organic solvent ( Non-patent document 1).

JP 2007-161707 A

Monthly display '11 June issue issued by Techno Times p. 31

  An object of the present invention is to provide a resist composition capable of producing a resist pattern having an excellent shape.

The present invention includes the following inventions.
[1] A resist composition comprising a resin containing a structural unit having an acid labile group, an acid generator represented by formula (I), and an acid generator represented by formula (II).
[In the formula (I),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and a methylene group constituting the alkanediyl group May be replaced by an oxygen atom or a carbonyl group.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the group may be replaced with an oxygen atom or a carbonyl group.
Z ⁺ represents an organic cation. ]
[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. May be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a C 1-6 fluorinated alkyl group.
s represents an integer of 1 to 10, and when s is 2 or more, the plurality of R ^f1 and R ^f2 are the same or different.
Z1 ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein the acid generator represented by the formula (I) is an acid generator represented by the formula (IA).
[In formula (IA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the methylene group constituting the hydrocarbon group is May be replaced by an oxygen atom or a carbonyl group.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 19 or less. ]
[3] Ring W is a ring represented by formula (IIa1-1), a ring represented by formula (IIa1-2), or a ring represented by formula (IIa1-3) [1] or [2 ] The resist composition as described.
[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be replaced by an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]
[4] L ¹ represents * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —. The resist composition according to any one of [1] to [3].
[5] The resist composition according to any one of [1] to [4], further containing a solvent.
[6] (1) A step of applying the resist composition according to any one of [1] to [5] 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 having an excellent shape can be produced.

It is sectional drawing showing the shape of a resist pattern.

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

<Resist composition>
The resist composition of the present invention comprises:
A resin comprising a structural unit having an acid labile group (hereinafter sometimes referred to as “resin (A)”),
An acid generator represented by formula (I) (hereinafter sometimes referred to as “acid generator (I)”), and
It contains an acid generator represented by the formula (II) (hereinafter sometimes referred to as “acid generator (II)”).
It is preferable that the resist composition of the present invention further contains a solvent (E).
The resist composition of the present invention may further contain a basic compound (C).

<Resin (A)>
The resin (A) includes a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”). Furthermore, a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) may be included.
In the present specification, the “acid labile group” is a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid. Means.

<Structural unit (a)>
The structural unit (a) is a structural unit having 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).
Wherein (1), R ^a1, R ^a2 and 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 combine with each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]
[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — constituting the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-.

^Examples of the alkyl group represented by R ^a1 , R ^a2 and 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 represented by R ^a1 , R ^a2 and R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). The alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 preferably has 3 to 16 carbon atoms.
Examples of the group obtained by combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

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. In each formula, R ^a3 has the same meaning as described above, and * represents a bond to —O—.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^a1 , R ^a2 and R ^a3 are alkyl groups in the formula (1), preferably tert-butoxycarbonyl). Group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantan-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 represented by R ^{a1 ′} , R ^{a2 ′} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group 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 R ^{a2 'and} R ^a3' is formed by bonding with, for example, R ^{a1 ',} R ^a2' is one obtained by removing groups a hydrogen atom from a hydrocarbon group and R ^{a3 '} Can be mentioned.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

  The monomer for deriving the structural unit (a) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

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

  As a structural unit derived from a (meth) acrylic monomer having a group represented by formula (1), preferably a structural unit represented by formula (a1-1) or a structure represented by formula (a1-2) Units are listed. 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, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^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 of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as the groups represented by R ^a1 , R ^a2, and R ^a3 in formula (1). .
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

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

Examples of the monomer (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclohexane-1- And yl (meth) acrylate. Monomers represented by the formula (a1-2-1) to the formula (a1-2-12) are preferred, and the formula (a1-2-3) to the formula (a1-2-4) or the formula (a1-2-9) The monomer represented by formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferable.

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

As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”) There are).
[In the formula (a1-5),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — [CH ₂ ] _k4 —CO—L ^a54 —. Here, k4 represents an integer of 1 to 4. * Represents a bond with L ^a51 .
L ^a51 , L ^a52 , L ^a53 and L ^a54 each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ^a51 is preferably an oxygen atom.
One of L ^a52 and L ^a53 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the monomer that leads to the structural unit (a1-5) include the following monomers.

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

<Structural unit (s)>
The monomer for deriving the “structural unit (s)” which is a structural unit having no acid labile group is not particularly limited as long as it is a monomer having no acid labile group, and a known monomer in the resist field can be used. .
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.

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

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

Examples of the monomer for deriving the structural unit (a2-1) include monomers described in JP 2010-204646 A. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

  When resin (A) contains structural unit (a2-1), the content rate is 3 to 45 mol% normally with respect to all the structural units of resin (A), Preferably it is 1 to 40 mol%. More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

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

  The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), or the formula (a3-3). These 1 type may be contained independently and 2 or more types may be contained.

[In the formula (a3-1),
L ^a4 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 are the same or different from each other.
In formula (a3-2),
L ^a5 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 are the same or different from each other.
In formula (a3-3),
L ^a6 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 are the same or different from each other. ]

In Formula (a3-1), Formula (a3-2), and Formula (a3-3), L ^a4 , L ^a5, and L ^a6 are each independently preferably an oxygen atom or an integer of k3 of 1 to 4. A group represented by * —O— (CH ₂ ) _k3 —CO—O—, more preferably an oxygen atom and * —O—CH ₂ —CO—O—, still more preferably an oxygen atom.
R ^a18 , R ^a19 , R ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

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

  When the resin (A) includes the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). More preferably, it is 10-60 mol%.

The content of the structural unit (a) in the resin (A) is preferably in the range of 1 to 100 mol%, more preferably in the range of 10 to 95 mol%, with respect to all the structural units of the resin (A). The range of 90 mol% is more preferable, and the range of 20 to 85 mol% is particularly preferable.
Resin (A) which has structural unit (a) with such a content rate can be manufactured by adjusting the use molar amount of the monomer with respect to the total molar amount of all the monomers used at the time of resin (A) manufacture.

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

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

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

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

<Resin other than resin (A)>
The resist composition of the present invention includes a resin other than the above-described resin (A), for example, a resin having at least one selected from structural units (s) and structural units derived from known monomers used in the field. Etc. may be contained.
When the resist composition of this invention contains resin other than resin (A), the content rate is 0.1-50 mass% normally with respect to the total amount of resin contained in the resist composition of this invention. , Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%.

  In the resist composition of the present invention, the total resin content is preferably 80% by mass or more and 99.9% by weight 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 resin content relative thereto can be measured, for example, by a known analytical means such as liquid chromatography or gas chromatography.

<Acid generator (I)>
The acid generator (I) is represented by the formula (I).
[In the formula (I),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and one or more constituting the alkanediyl group The methylene group may be replaced with an oxygen atom or a carbonyl group.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, One or more methylene groups constituting the group may be replaced with an oxygen atom or a carbonyl group.
Z ⁺ represents an organic cation. ]

Examples of the alkanediyl group of X ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, butane-1,3-diyl group, 2-methylpropane -1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and the like.
Of these, a methylene group is preferable.

Examples of the group in which one or more methylene groups constituting the alkanediyl group are replaced with an oxygen atom or a carbonyl group include the following divalent groups. * Represents a bond with CF ₂ .

Examples of the group in which the hydrogen atom contained in the alkanediyl group is substituted with a hydroxy group or —OR ^{5 and} at least one methylene group constituting the alkanediyl group is replaced with an oxygen atom include the following groups. . * Represents a bond with CF ₂ .

The hydrocarbon group for R ⁴ and R ⁵ may be either saturated or unsaturated, for example, a linear or branched alkyl group or alkenyl group, a monocyclic or polycyclic alicyclic hydrocarbon group , Aromatic hydrocarbon groups and the like, and a combination of two or more of these groups may be used.
Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of the branched alkyl group include an isopropyl group, a sec-butyl group, and a tert-butyl group.
Examples of the linear or branched alkenyl group include a vinyl group and an α-methylvinyl group.
Examples of the monocyclic alicyclic hydrocarbon group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
Examples of the polycyclic alicyclic hydrocarbon group include a norbornyl group and an adamantyl group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, 2,6-diethylphenyl group, 2- And methyl-6-ethylphenyl.

The acid generator (I) is preferably an acid generator represented by the formula (IA).
[In formula (IA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and one or more constituting the hydrocarbon group The methylene group may be replaced with an oxygen atom or a carbonyl group.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 19 or less. ]

Examples of the hydrocarbon group for R ⁶ include the same groups as those for R ⁴ , and an alicyclic hydrocarbon group is preferable.
Examples of the group in which one or more methylene groups constituting the hydrocarbon group are replaced with an oxygen atom or a carbonyl group include the following. * Represents a bond.
Examples of the alkyl group for R ⁷ include a methyl group, an ethyl group, a propyl group, and a butyl group.
As the fluorinated alkyl group for R ⁸ , a trifluoromethyl group, a perfluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluorobutyl group, 1,1,2,2,3,3, Examples include 4,4-octafluorobutyl group, and a trifluoromethyl group is preferable.

Examples of the acid generator (I) include the following salts.

Examples of Z ⁺ 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, an arylsulfonium cation is more preferable, and a cation represented by any one of the formulas (b2-1) to (b2-4) [hereinafter, depending on the formula number Sometimes referred to as “cation (b2-1)”. ] Is more preferable.

In formula (b2-1) to formula (b2-4),
Each of R ^{b4 to} R ^b6 independently represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms; , R ^b4 and R ^b5 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 saturated hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group is substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, the plurality of R ^b7 are the same or different from each other, and when n2 is 2 or more, the plurality of R ^b8 are the same or different from each other.
R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or R ^b9 and R ^b10 are combined together. Together with the sulfur atom to which they are attached, forms a 3- to 12-membered ring (preferably a 3- to 7-membered ring). One or more —CH ₂ — constituting the ring may be replaced by —O—, —SO— or —CO—.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group has 1 to 12 carbon atoms. Or an alkoxycarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) together with —CH—CO— to which they are bonded. One or more —CH ₂ — constituting the ring may be replaced by —O—, —SO— or —CO—.
R ^{b13 to} R ^b18 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.
L ^b24 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are the same or different from each other. When p2 is 2 or more, the plurality of R ^b14 are the same or different from each other. When q2 is 2 or more, the plurality of R ^b15 are the same. Alternatively, when r2 is 2 or more, a plurality of R ^b16 are the same or different from each other, when s2 is 2 or more, a plurality of R ^b17 are the same or different from each other, and when t2 is 2 or more, a plurality of R ^{b16 b18} are the same or different from each other.

R ^b4 and R ^b5 may together form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with the sulfur atom to which they are bonded.

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- An ethylhexyl group is mentioned. In particular, the aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 4 to 12 carbon atoms.

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

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

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

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

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

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

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

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

  The acid generator (I) is a combination of the above anions and the above cations. These can be arbitrarily combined, and among them, the salt represented by the following is preferable.

The acid generator (I) can be obtained, for example, by reacting a salt represented by the formula (I-0-1) with a compound represented by the formula (I-0-2) in a solvent. . Examples of the solvent include chloroform.
[Wherein, X ² , R ⁴ and Z ⁺ represent the same meaning as described above. ]

Examples of the salt represented by the formula (I-0-1) include salts represented by the following.

The compound represented by the formula (I-0-2) is obtained by reacting a salt represented by the formula (I-0-3) with a compound represented by the formula (I-0-4) in a solvent. Can be obtained.
Examples of the solvent include chloroform.
[Wherein R ⁴ represents the same meaning as described above. ]
Examples of the compound represented by the formula (I-0-3) include compounds represented by the following.

The salt represented by the formula (IA) can be obtained, for example, by reacting the salt represented by the formula (IA-1) with the compound represented by the formula (IA-2) in a solvent. Examples of the solvent include chloroform.
[Wherein, X ² , R ⁶ , R ⁷ , R ⁸ and Z ⁺ represent the same meaning as described above. ]

The salt represented by the formula (IA-1) is obtained by reacting the salt represented by the formula (IA-3) and the compound represented by the formula (IA-4) in a solvent in the presence of an acid catalyst. Can be manufactured. Examples of the solvent include dimethylformamide. Examples of the acid catalyst include p-toluenesulfonic acid.
[Wherein, X ² , R ⁷ , R ⁸ and Z ⁺ represent the same meaning as described above. ]
Examples of the salt represented by the formula (IA-3) include salts represented by the following.
Examples of the compound represented by the formula (IA-4) include ethyl trifluoropyruvate.

The compound represented by the formula (IA-2) can be obtained by reacting the salt represented by the formula (IA-5) and the compound represented by the formula (IA-6) in a solvent. .
Examples of the solvent include chloroform.
[Wherein R ⁶ represents the same meaning as described above. ]
Examples of the compound represented by the formula (IA-5) include compounds represented by the following.

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

<Acid generator represented by formula (II)>
The acid generator (II) is represented by the formula (II).
[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. May be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a C 1-6 fluorinated alkyl group.
s represents an integer of 1 to 10, and when s is 2 or more, the plurality of R ^f1 and R ^f2 are the same or different.
Z1 ⁺ represents an organic cation. ]
In the formula (II), those having a negative charge obtained by removing the organic cation represented by Z1 ⁺ having a positive charge may be referred to as “sulfonate anion”.

In the formula (II), examples of the perfluoroalkyl group of Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluorotert- Examples thereof include a butyl group, a perfluoropentyl group, and a perfluorohexyl group.
Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group of L ^a and L ^b constituting L ¹ include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated carbon group. A hydrogen group may be mentioned, and two or more of these groups may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl A branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.
The divalent alicyclic hydrocarbon group may be a group obtained by removing any one hydrogen atom from a monovalent alicyclic hydrocarbon group described later.

Examples of the group in which the methylene group in the divalent saturated hydrocarbon group of L ¹ is replaced by an oxygen atom or a carbonyl group are represented by any of the following formulas (b1-1) to (b1-7). Groups. Formulas (b1-1) to (b1-7) are described in accordance with Formula (I) on the left and right, and of the two bonds represented by *, the left bond is C ( Q ¹ ) is bonded to the carbon atom of (Q ² ). 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 total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b7 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 represents a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms. L ^b10 represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
L ^b11 and L ^b12 each independently represent a single bond or a saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b11 and L ^b12 is 14.

L ¹ is preferably a group represented by any one of formulas (b1-1) to (b1-5), more preferably any one of formulas (b1-1) to (b1-4). A group represented by formula (b1-1) or formula (b1-3), particularly preferably a divalent group represented by formula (b1-1). is there. Among them, preferably, L ^b2 in formula (b1-1) is a single bond or a saturated hydrocarbon group having 1 to 6 carbon atoms, and more preferably * —CO—O— (CH ₂ ) _t — (t is Represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —, and more preferably a formula (b1—) wherein L ^b2 is a single bond or a methylene group. A divalent group represented by 1), more preferably a divalent group represented by formula (b1-1) in which L ^b2 is a single bond, that is, * —CO—O—.

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.

The alicyclic hydrocarbon ring having 3 to 36 carbon atoms in the ring W may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon ring include cyclopentane and cyclohexene. Examples include cycloalkane rings such as xane, methylcyclohexane, dimethylcyclohexane, cycloheptane, and cyclooctane ring. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthalene, adamantane, norbornane, methylnorbornane ring, and the following rings.
Among these, the ring W is preferably a ring represented by the formula (IIa1-1), a ring represented by the formula (IIa1-2), or a ring represented by the formula (IIa1-3).
[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]

Saturated hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and other alkyl groups; cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Cycloalkyl groups such as: a group in which an alkyl group such as a methylcyclohexyl group or a dimethylcyclohexyl group and a cycloalkyl group are combined.
Examples of the alkoxy group include 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-pentyloxy group, and an n-hexyloxy group. Can be mentioned.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenylyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.

In the ring W described above, the position of the bond between L ¹ and two oxygen atoms can be any position. Among them, in the ring represented by the formula (IIa1-1), the ring represented by the formula (IIa1-2) or the ring represented by the formula (IIa1-3), the bond * is the following position. Those are preferred.

Examples of the fluorinated alkyl group for R ^f1 and R ^f2 include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1, 2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2 , 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluol) Olopropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5- Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2, 2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentyl A methyl group and a perfluorohexyl group are mentioned. Of these, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, and the like are preferable.
R ^f1 and R ^f2 are preferably fluorine atoms.

s is preferably an integer of 1 to 8, more preferably an integer of 1 to 6, more preferably an integer of 1 to 4, or a ring containing 1 or 2, that is, —O—C—O—.
However, those having the following groups are particularly preferred.

Specific examples of the sulfonate anion of formula (II) include the following.

Examples of the organic cation represented by Z ⁺ include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. 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 be combined to form a ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be 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, and an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aliphatic hydrocarbon group includes The hydrogen atom contained may be substituted with an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group is , 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 carbon It may be substituted with an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
P ⁸ and P ⁹ may combine to form a ring containing —CH—CO— to which they are attached.

P ¹⁰ to P ¹⁵ each independently represent a hydroxy group, an aliphatic hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
E represents -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, a plurality of P ¹⁴ are the same or different from each other, when y is 2 or more, a plurality of P ¹⁵ are the same or different from each other.

Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned. In particular, the aliphatic hydrocarbon group of R ^{6 to} R ⁹ preferably has 1 to 12 carbon atoms.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group. In this case, examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. It is done. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. * Represents a bond.
In particular, the alicyclic hydrocarbon group of R ^{6 to} R ⁹ preferably has 4 to 18 carbon atoms.
Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. Groups and the like.
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 aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, a naphthylethyl group, and the like. .

The ring formed by combining P ^a and P ^b may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, and a sulfur atom As long as it contains one or more, it may further contain one or more oxygen atoms, that is, —O—, —S—, or —CO—. 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, If it contains one or more, it may further contain one or more oxygen atoms, that is, —O—, —S—, and —CO—. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.
The ring formed by combining P ⁸ and P ⁹ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, 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 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 containing a sulfur 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, when z2 is 2 or more, P ² are the same or different, when z3 is 2 or more, a plurality of P ³ are the same Or different.

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 further contain one or more oxygen atoms.
The P ^{1 to} P ³ aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
Among these, P ^{1 to} P ³ each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, or P ¹ 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 (II) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned sulfonate anion and organic cation can be arbitrarily combined. In the following formulae, the definition of the substituent has the same meaning as described above.

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

Of the acid generator (II), a method for producing a compound represented by the formula (b1) is shown below.
(In the formula, Q ¹ , Q ² , W, R ^{f 1} , R ^{f 2} , s and Z ⁺ are as defined above.)

First, a salt represented by the formula (b1) is prepared by reacting a salt represented by the formula (b1-a) with a compound represented by the formula (b1-b) in a solvent under an acid catalyst condition. Get. Examples of the solvent include 1,2-dichloroethane. Examples of the catalyst include p-toluenesulfonic acid.

The salt represented by the formula (b1-a) can be synthesized, for example, by the method described in JP2007-224008A.
Examples of the compound represented by the formula (b1-b) include 2,2,3,3-tetrafluoro-1,4-butanediol.

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

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

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

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

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents a hydrogen atom, a fluorine atom, or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Zb ⁺ represents an organic cation. ]

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

Examples of the saturated hydrocarbon group for L ^b1 include an aliphatic saturated hydrocarbon group such as a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic alicyclic saturated hydrocarbon group, A combination of two or more of these groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Branched alkanediyl groups such as diyl groups;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which one or more methylene groups constituting the saturated hydrocarbon group of L ^b1 are replaced by an oxygen atom or a carbonyl group include those represented by any of formulas (b1′-1) to (b1′-7). Group to be used. L ^b1 is preferably a group represented by any one of formulas (b1′-1) to (b1′-4), more preferably represented by formula (b1′-1) or formula (b1′-2). Group to be used. In addition, Formula (b1'-1)-Formula (b1'-7) has described the right and left according to Formula (B1), and it is C on the left side among the two bonds represented by *, respectively. It binds to (Q ^b1 ) (Q ^b2 ) — and on the right side to —Y. The same applies to specific examples of the following formulas (b1′-1) to (b1′-7).

In formula (b1′-1) to formula (b1′-7),
L ^{b2 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b3 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^{b4 ′} represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms. However, the upper limit of the carbon number of L ^{b3 ′} and L ^{b4 ′} is 20.
L ^{b5 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b6 ′} represents a divalent saturated hydrocarbon group having 1 to 22 carbon atoms. However, the upper limit of the total carbon number of L ^{b5 ′} and L ^{b6 ′} is 22.
L ^{b7 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b8 ′} represents a divalent saturated hydrocarbon group having 1 to 23 carbon atoms. However, the upper limit of the total carbon number of L ^{b7 ′} and L ^{b8 ′} is 23.
L ^{b9 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^{b10 ′} represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. However, the upper limit of the total carbon number of L ^{b9 ′} and L ^{b10 ′} is 21.
L ^{b11 ′} and L ^{b12 ′} represent a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^{b13 ′} represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. However, the upper limit of the total carbon number of L ^{b11 ′} , L ^{b12 ′} and L ^{b13 ′} is 19.
L ^{b14 ′} and L ^{b15 ′} each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^{b16 ′} represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. However, the upper limit of the total carbon number of L ^{b14 ′} , L ^{b15 ′} and L ^{b16 ′} is 21.

Among them, L ^b1 is preferably any one of the formulas (b1′-1) to (b1′-4), more preferably the formula (b1′-1) or the formula (b1′-2), and more preferably the formula A divalent group represented by (b1′-1), particularly preferably a divalent group represented by the formula (b1′-1) in which L ^{b2 ′} is a single bond or —CH ₂ —. is there.

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 saturated hydrocarbon group of L ^b1 is substituted with a fluorine atom or a hydroxy group include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y26).

  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 the substituent for the alicyclic hydrocarbon group in Y 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 3 to 3 carbon atoms. 16 alicyclic hydrocarbon groups, alkoxy groups having 1 to 12 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, aralkyl groups having 7 to 21 carbon atoms, acyl groups 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 6 to 6 carbon atoms). 18 represents an aromatic hydrocarbon group, and j2 represents an integer of 0 to 4.

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

Examples of Y include the following.

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

The sulfonate anion in the salt (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt (B1) include anions described in JP 2010-204646 A.

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

  Examples of the salt (B1) include salts represented by formulas (B1-1) to (B1-20), respectively. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11) ), Formula (B1-12), Formula (B1-13), Formula (B1-14), Formula (B1-18), Formula (B1-19), or Formula (B1-20). More preferred are salts.

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

In the resist composition, the content of the acid generator (I) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (100 parts by mass) with respect to 100 parts by mass of the resin (A). More preferably, it is 25 parts by mass or less.
In the resist composition, the content of the acid generator (II) is preferably 1 part by mass (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (100 parts by mass) with respect to 100 parts by mass of the resin (A). More preferably, it is 25 parts by mass or less.
When the resist composition contains the acid generator (I) and the acid generator (II), the total content of the acid generator (I) and the acid generator (II) is 100 masses of the resin (A). The amount is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less). In this case, the content ratio (mass ratio) of the acid generator (I) and the acid generator (II) is, for example, 5:95 to 95: 5, preferably 10:90 to 90:10, and more preferably 15 : 85-85: 15.
When the resist composition contains an acid generator (I), an acid generator (II), and an acid generator (B), the acid generator (I), the acid generator (II), and the acid generator (B ) With respect to 100 parts by mass of the resin (A), preferably 1 part by mass (more preferably 3 parts by mass), preferably 40 parts by mass (more preferably 35 parts by mass). It is.
The ratio (mass ratio) of the total content of the acid generator (I) and the acid generator (II) and the content of the acid generator (B) is, for example, 5:95 to 95: 5, Preferably it is 10: 90-90: 10, More preferably, it is 15: 85-85: 15.

<Solvent (E)>
The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and 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 may contain individually by 1 type and may contain 2 or more types.

<Basic compound (C)>
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. 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 any one of the formulas (C1) to (C8) and (C1-1), more preferably represented by the formula (C1-1). The compound which is made is mentioned.

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

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

[In Formula (C2), Formula (C3) and Formula (C4), R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an 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 from each other. ]

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

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

In formula (C1) to formula (C8) and formula (C1-1), the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group, alkanediyl group are the same as those described above. Is mentioned.
Examples of the 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 in 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 may contain other components (F) as necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

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

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) 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) The process of heating the composition layer after exposure, (5) The process of developing the composition layer after a heating is included.

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

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

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. 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 types of laser light such as those that convert the wavelength of laser light from the laser to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, those that irradiate an electron beam or extreme ultraviolet light (EUV), etc. it can.

  The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction of the resin (A). As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.

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

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

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

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

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

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

Synthesis Example 1: Synthesis of salt represented by formula (I-1)
The salt represented by the formula (I1-a) was synthesized by the method described in JP-A-2008-7409. 10.00 parts of salt represented by formula (I1-a), 50.00 parts of dimethylformamide, 4.18 parts of compound represented by formula (I1-b) and 0.70 parts of p-toluenesulfonic acid And stirred at 100 ° C. for 2 hours. To the obtained reaction solution, 200 parts of chloroform and 50 parts of ion-exchanged water were added, stirred for 30 minutes, and separated. This washing operation was repeated three times. The collected organic layer is concentrated, and the concentrate is fractionated in a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to give a salt represented by the formula (I1-c) 2. 43 parts were obtained.

0.63 part of a compound represented by the formula (I1-d) and 10 parts of chloroform were charged, stirred at 23 ° C. for 30 minutes, 0.55 part of a compound represented by the formula (I1-e) was charged, and 60 ° C. For 1 hour. The obtained reaction product was cooled to 23 ° C. and filtered to obtain a solution containing a compound represented by the formula (I1-f). A solution containing the compound represented by the formula (I1-f) was charged with 2.10 parts of the salt represented by the formula (I1-c) and stirred at 60 ° C. for 6 hours. To the obtained reaction product, 50 parts of chloroform and 20 parts of ion-exchanged water were charged, stirred and separated. Water washing was performed 5 times. The obtained organic layer was concentrated, and the resulting concentrate was dissolved in 20 parts of acetonitrile and concentrated. To the obtained concentrate, 30 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.69 parts of the salt represented by the formula (I-1).

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 573.1

Synthesis Example 2: Synthesis of salt represented by formula (II-1)

A salt represented by the formula (II-1-a) was synthesized by the method described in JP-A-2007-224008.
10.00 parts of the salt represented by the formula (II-1-a) and 40 parts of 1,2-dichloroethane were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (II-1-b) and 0.30 parts of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. To the recovered organic layer, 120 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 8.14 parts of acetonitrile and 48.84 parts of tert-butyl methyl ether were added and stirred, stirred at 23 ° C. for 1 hour, filtered, and 8.25 of the salt represented by the formula (II-1). Got a part.

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 3: Synthesis of salt represented by formula (II-2)
A salt represented by the formula (II-2-b) was synthesized by the method described in JP 2008-94835 A.
17.50 parts of the salt represented by the formula (II-2-a), 25.00 parts of the salt represented by the formula (II-2-b) (purity: 90.8%), 125.00 parts of chloroform, 41.67 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 12 hours for liquid separation. The recovered organic layer was charged with 31.25 parts of ion exchanged water, and stirred and separated. This washing with water was performed nine times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. Concentrate the filtrate, add 50 parts of acetonitrile to the resulting concentrate, dissolve, concentrate, add 173.13 parts of tert-butyl methyl ether to the resulting residue, stir and filter. Gave 28.42 parts of the salt represented by the formula (II-2-c).

10.72 parts of a salt represented by the formula (II-2-c) and 42.88 parts of 1,2-dichloroethane were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (II-1-b) and 0.30 parts of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. To the recovered organic layer, 120 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 9.12 parts of acetonitrile and 54.72 parts of tert-butyl methyl ether were added and stirred, stirred at 23 ° C. for 1 hour, filtered, and 8.49 of the salt represented by the formula (II-2). Got a part.

MS (ESI (+) Spectrum): M ⁺ 305.1
MS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 4: Synthesis of salt represented by formula (II-3)

  10.00 parts of the compound represented by the formula (II-3-b) obtained by the method described in JP2008-209917A, and the salt 11.26 represented by the formula (II-3-a) Part, chloroform 50 parts and ion-exchanged water 25 parts, and 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 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-3-c). .75 parts were obtained.

11.71 parts of a salt represented by the formula (II-3-c), 1.70 parts of a compound represented by the formula (II-3-d) and 46.84 parts of monochlorobenzene were charged and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the resulting residue, stirred, and then filtered to obtain the salt represented by the formula (II-3-e) 6. 84 parts were obtained.

4.98 parts of the salt represented by the formula (II-3-e) and 25.00 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 2.17 parts of a compound represented by the formula (II-1-b) and 0.09 part of sulfuric acid were added, followed by stirring at 60 ° C. for 15 hours. The obtained reaction product was cooled to 23 ° C., 120 parts of ion exchange water was added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. The recovered organic layer was charged with 12.50 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 41.35 parts of tert-butyl methyl ether was added and stirred, and then the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 4.84 parts of the salt represented by the formula (II-3).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (−) Spectrum): M ^- 467.1

Synthesis Example 5: Synthesis of salt represented by formula (B1-5)
50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of the salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis of Resin (A) Compounds (monomers) used in the synthesis of resin (A) are shown below.
Hereinafter, these monomers are referred to as “monomer (a1-1-3)” or the like according to the formula number.

Synthesis Example 6 [Synthesis of Resin A1]
As the monomer, using monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (a3-1-1)] It mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and the resin was filtered to obtain a resin A1 having a weight average molecular weight of 7.8 × 10 ³ (co-polymer). Polymer) with a yield of 73%. This resin A1 has the following structural units and was soluble in butyl acetate.

Synthesis Example 7 [Synthesis of Resin A2]
As the monomer, using monomer (a1-1-3), monomer (a1-2-3), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-3): monomer (a3-2-3): monomer (a3-1-1)] It mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and this resin was filtered to obtain a resin A2 having a weight average molecular weight of 7.8 × 10 ³ (co-polymer). Polymer) with a yield of 70%. This resin A2 had the following structural units and was soluble in butyl acetate.

Synthesis Example 8 [Synthesis of Resin A3]
Monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) are mixed in a molar ratio [monomer (a1-1-2): monomer (a2-1-1): Monomer (a3-1-1)] was mixed so as to be 50:25:25, and 1.5 mass times dioxane was further 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. did. This was polymerized by heating at 80 ° C. for about 8 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. Again, the resin is dissolved in dioxane, poured into a mixed solvent of a large amount of methanol and water, the resin is precipitated, and the precipitated resin is filtered and recovered three times for reprecipitation purification, and the weight average Resin A3 (copolymer) having a molecular weight of about 9.2 × 10 ³ was obtained in a yield of 60%. This resin A3 had the following structural units and was soluble in butyl acetate.

Synthesis Example 9 [Synthesis of Resin A4]
As the monomer, using monomer (a1-1-3), monomer (a1-5-1), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-5-1): monomer (a2-1-3): monomer (a3-2-3)): monomer (a3-1-1)] However, it mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 6 × 10 ³ resin A4 was obtained with a yield of 68%. This resin A4 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A5]
As the monomer, using monomer (a1-1-2), monomer (a1-5-1), monomer (a2-1-1), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-2): monomer (a1-5-1): monomer (a2-1-1): monomer (a3-2-3)): monomer (a3-1-1)] Was mixed to be 30: 14: 6: 20: 30, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added 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 propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A5 (copolymer) having a molecular weight of 7.9 × 10 ³ was obtained in a yield of 85%. This resin A5 has the following structural units.

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

<Resin>
Resins A1 to A5 synthesized in the synthesis example described above,
<Acid generator>
I1: Salt represented by formula (I-1) I2: Central Glass Co., Ltd.
II1: Salt represented by the formula (II-1)
II2: salt represented by the formula (II-2)
II3: salt represented by formula (II-3)
B1-3: synthesized according to the example of JP 2010-152341 A

B1-5:
B1-X: synthesized according to the example of JP-A No. 2007-161707

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

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

Examples 1-8 and Comparative Example 1
<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer, and baked under the conditions of 205 ° C. and 60 seconds, whereby an organic layer having a thickness of 78 nm. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 100 nm. After the application, this silicon wafer was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 1 for 60 seconds to form a composition layer on the silicon wafer. The composition layer formed on the silicon wafer was subjected to an immersion exposure ArF excimer laser stepper [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized illumination], and a line and space pattern. Using a mask for forming (pitch 100 nm / line width 50 nm), exposure was performed while changing the exposure amount in stages. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

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

<Shape evaluation>
The cross-sectional shape of the line pattern manufactured with effective sensitivity was observed with a scanning electron microscope. A top shape that is close to a rectangle (FIG. 1 (a)) was marked with ◯, and a round top shape (FIG. 1 (b)) was marked with x. The results are shown in Table 2.

Examples 9 to 16 and Comparative Example 2
Except that the developer used in the development process was changed from n-butyl acetate to 2-heptanone (manufactured by Kyowa Hakko Co., Ltd.), the same operation as above was performed to produce a negative resist pattern. Similar evaluations were made. The results are shown in Table 3.

  From the above results, it can be seen that the resist composition of the present invention can produce a resist pattern having an excellent shape.

<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.

Examples 17 to 20 and Comparative Example 3
<Manufacture of positive resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 4. Using the ArF excimer stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] on the wafer on which the resist composition film is formed in this manner, the exposure amount is stepwise. The line and space pattern was subjected to immersion exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed for 60 seconds on a hot plate at the temperature described in the “PEB” column of Table 4, and then with an aqueous 2.38 mass% tetramethylammonium hydroxide solution for 60 seconds. Paddle development was performed to obtain a resist pattern.

  In each of the obtained resist pattern films, an exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as an effective sensitivity.

<Shape evaluation>
The cross-sectional shape of the line pattern manufactured with effective sensitivity was observed with a scanning electron microscope. A top shape that is close to a rectangle (FIG. 1 (a)) was marked with ◯, and a round top shape (FIG. 1 (b)) was marked with x. The results are shown in Table 5.

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

  According to the resist composition of the present invention, a resist pattern having a good shape can be produced, and can be used for fine processing of semiconductors.

Claims (6)

A resist composition comprising a resin comprising a structural unit having an acid labile group, an acid generator represented by formula (I), and an acid generator represented by formula (II).
[In the formula (I),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and a methylene group constituting the alkanediyl group May be replaced by an oxygen atom or a carbonyl group.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the group may be replaced with an oxygen atom or a carbonyl group.
Z ⁺ represents an organic cation. ]
[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. May be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a C 1-6 fluorinated alkyl group.
s represents an integer of 1 to 10, and when s is 2 or more, the plurality of R ^f1 and R ^f2 are the same or different.
Z1 ⁺ represents an organic cation. ] 2. The resist composition according to claim 1, wherein the acid generator represented by the formula (I) is an acid generator represented by the formula (IA).
[In formula (IA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the methylene group constituting the hydrocarbon group is May be replaced by an oxygen atom or a carbonyl group.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 19 or less. ] The resist composition according to claim 1 or 2, wherein the ring W is a ring represented by the formula (IIa1-1), a ring represented by the formula (IIa1-2), or a ring represented by the formula (IIa1-3). object.
[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be replaced by an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ] L ¹ is * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —). The resist composition according to any one of claims 1 to 3.   Furthermore, the resist composition as described in any one of Claims 1-4 containing a solvent. (1) The process of apply | coating the resist composition as described in any one of Claims 1-5 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.