JP6030842B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

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

JP 2010-197413 A

  A resist pattern manufactured from a conventional resist composition may not always satisfy the CD uniformity or may have many defects.

The present invention includes the following inventions.
[1] (A1) a resin having a structural unit represented by formula (I),
(A2) A resist composition containing a resin that is insoluble or hardly soluble in an alkaline aqueous solution and that can be dissolved in an alkaline aqueous solution by the action of an acid; and (B) an acid generator having a structure that is cleaved by the action of an alkaline developer.

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]
[2] The resist composition according to [1], wherein R ² is a fluorinated alkyl group having 1 to 6 carbon atoms.
[3] The resist composition according to [1] or [2], wherein A ¹ is a methylene group.
[4] In the acid generator, any one of [1] to [3], wherein the structure that is cleaved by the action of an alkali developer is a group represented by the formula (Ba) or a group represented by the formula (Bb) The resist composition as described.
[In Formula (Ba), R ³ represents a C 1-6 alkyl group having a fluorine atom. ]
[In formula (Bb), R ⁴ represents a C 1-6 alkyl group having a fluorine atom.
R ⁵ and R ⁶ each independently represents a hydrogen atom or a fluorine atom. ]
[5] The acid generator having a structure that is cleaved by the action of an alkali developer is an acid generator represented by the formula (II-a) or an acid generator represented by the formula (II-b) [1. ]-[4] The resist composition in any one of.
[In formula (II-a) or formula (II-b),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a single bond or a divalent alkanediyl group having 1 to 17 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—.
Y represents a C 3-18 divalent alicyclic hydrocarbon group, and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O— or —CO—. .
R ^{3 to} R ⁶ represent the same meaning as described above.
Z ⁺ represents an organic cation. ]
[6] The resist composition according to any one of [1] to [5], further containing a solvent.
[7] (1) A step of applying the resist composition according to any one of [1] to [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a resist pattern having excellent CD uniformity and few occurrences of defects can be produced.

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

<Resist composition>
The resist composition of the present invention comprises:
(A) Resin (hereinafter sometimes referred to as “resin (A)”) and (B) Acid generator having a structure that is cleaved by the action of an alkali developer (hereinafter sometimes referred to as “acid generator (B)”) Containing.
Here, the resin (A) includes the following resins.
(A1) a resin having a structural unit represented by the formula (I) (hereinafter sometimes referred to as “resin (A1)”) and (A2) insoluble or hardly soluble in an aqueous alkali solution, Resin that becomes soluble (hereinafter sometimes referred to as “resin (A2)”).
The resist composition of the present invention preferably further contains a solvent (E) (hereinafter sometimes referred to as “solvent (E)”).
The resist composition of the present invention preferably further contains a basic compound (hereinafter sometimes referred to as “basic compound (C)”).
<Resin (A)>
The resin (A) contained in the resist composition of the present invention includes the above-described resins (A1) and (A2). Moreover, resin other than resin (A1) and (A2) which is mentioned later may be contained.

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

A ^{1 in} formula (I) is preferably — (CH ₂ ) _m1 —, more preferably an ethylene group or a methylene group, and still more preferably a methylene group.

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

Examples of the hydrocarbon group having a fluorine atom include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include difluoromethyl group, trifluoromethyl group, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2 , 2,2-trifluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, 1,1,1,2,2- Pentafluoropropyl group, perfluoropropyl group, 1,1,1,2,2,3,3-peptafluorobutyl group, perfluorobutyl group, 1,1,1,2,2,3,3,4,4 -Fluoroalkyl groups such as nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group and perfluorooctyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.
R ² is preferably a fluorinated alkyl group, more preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

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

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

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

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

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

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

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

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

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

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

<Resin (A2)>
The resin (A2) is insoluble or hardly soluble in the alkaline aqueous solution and can be dissolved in the alkaline aqueous solution by the action of an acid. Here, “can be dissolved in an alkaline aqueous solution by the action of an acid” means having an acid labile group (hereinafter sometimes referred to as “acid labile group”), and an alkaline aqueous solution before contact with the acid. It is insoluble or hardly soluble in water, but it becomes soluble in an aqueous alkali solution after contact with an acid.
Therefore, the resin (A2) is obtained by polymerizing one or more of monomers (a1) having an acid labile group, which will be described later (hereinafter sometimes referred to as “acid labile monomer (a1)”). Can do. In addition, as long as the resin (A2) has the above-described properties, the structural unit derived from the acid-stable monomer described later, the structural unit derived from a monomer known in the art, the structural unit (I) and the formula (IIIA) described above The structural unit represented by these may be included.
The resin (A2) may be a different resin different from the resin (A1), or has a structural unit represented by the formula (I) and a structural unit represented by the formula (IIIA), and an alkali. A resin that is insoluble or hardly soluble in an aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid may be used.

<Acid labile monomer (a1)>
The “acid-labile group” means a group having a leaving group and leaving the leaving group upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

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

^Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups.
In Formula (1), the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

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

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

Examples of the hydrocarbon group for R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include a group in which one hydrogen atom has been removed from the hydrocarbon group of R ² in formula (I).
In Formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups.

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

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

  As a structural unit derived from a (meth) acrylic monomer having an acid labile group and an alicyclic hydrocarbon group, the structural unit represented by the formula (a1-1) or the formula (a1-2) The structural unit represented by these is mentioned. These may be used alone or in combination of two or more.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents 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 for R ^a6 and R ^a7 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, Examples thereof include cycloalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.
The alicyclic hydrocarbon group 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 which guide | induces the structural unit represented by a formula (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Monomers represented by the following formulas (a1-1-1) to (a1-1-8) are preferred, and monomers represented by the following formulas (a1-1-1) to (a1-1-4) are more preferred. .

Examples of the monomer for deriving the structural unit represented by the formula (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethyl. Examples include cycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate. Monomers represented by the following formulas (a1-2-1) to (a1-2-12) are preferred, and the following formulas (a1-2-3) to (a1-2-4) and the following formulas (a1-2-2) The monomers represented by 9) to (a1-2-10) are more preferable, and the monomers represented by the following formula (a1-2-3) and the following formula (a1-2-9) are more preferable.

  When the resin (A2) includes the structural unit represented by the formula (a1-1) and / or the structural unit represented by the formula (a1-2), the total content thereof is the total structure of the resin (A2). It is 10-95 mol% normally with respect to a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

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

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

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

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

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

  When the resin (A2) includes a structural unit derived from the monomer represented by the formula (a2-1), the content is usually 3 to 45 mol% with respect to all the structural units of the resin (A2). , Preferably it is 3-40 mol%, More preferably, it is 3-35 mol%.

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

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

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

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

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

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

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

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

  The resin (A2) is preferably a copolymer of an acid labile monomer (a1) and an acid stable monomer. In this copolymer, the acid labile monomer (a1) is more preferably a monomer that leads to a structural unit represented by the formula (a1-1) having an adamantyl group and a structural unit represented by the formula (a1-2) Is a monomer that leads to a structural unit represented by the formula (a1-1), more preferably at least one of the monomers that lead to (preferably the monomer having a cyclohexyl group or a cyclopentyl group). The acid stable monomer is preferably an acid stable monomer (a2) having a hydroxy group and / or an acid stable monomer (a3) having a lactone ring. The acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer (a2-1) having a hydroxyadamantyl group, and the acid-stable monomer (a3) having a lactone ring is more preferably a γ-butyrolactone ring. The acid-stable monomer (a3-1) and the acid-stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring.

Each structural unit constituting the resin (A2) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The weight average molecular weight of the resin (A2) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less).

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

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

  In the resist composition of the present invention, the resin content is preferably 80% by mass or more and 99% by mass or less in the solid content of the resist composition. In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the content of the resin (A) relative thereto can be measured, for example, by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator (B) has a structure that is cleaved by the action of an alkali developer.
The structure that is cleaved by the action of an alkali developer refers to a structure that is cleaved by the action of an alkali developer in the development process for producing a resist pattern. In other words, it refers to a base dissociable group that is decomposed by the action of an alkali and converted into an alkali-soluble group.
When such an acid generator (B) comes into contact with an alkaline developer in the development step, this structure is cleaved to form a hydrophilic group (for example, a hydroxy group or a carboxy group).
As used herein, the term “cleavage” means that the bond is broken and divided into a plurality of molecules, and does not include a ring-opening reaction.

The structure that is cleaved by the action of the alkali developer is preferably a group represented by the following formula (Ba) or a group represented by the formula (Bb).
[In Formula (Ba), R ³ represents a C 1-6 alkyl group having a fluorine atom. ]
[In formula (Bb), R ⁴ represents a C 1-6 alkyl group having a fluorine atom.
R ⁵ and R ⁶ each independently represents a hydrogen atom or a fluorine atom. ]

  In the formula (Ba) and the formula (Bb), examples of the alkyl group having a fluorine atom include the same as the above-described fluorinated alkyl group, for example, 1,1,1-trifluoroethyl group, perfluoroethyl group. 1,1,1,2,2-pentafluoropropyl group, perfluoropropyl group, 1,1,1,2,2,3,3-peptafluorobutyl group, perfluorobutyl group, 1,1,1, 2,2,3,3,4,4-nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group and the like are preferable.

For example, the group represented by the formula (Ba) is cleaved by the action of an alkali to generate a hydroxy group. The group represented by the formula (Bb) is cleaved by the action of an alkali to generate a carboxy group.
It can be confirmed that the acid generator (B) having such a structure (base dissociable group) is cleaved by the following method.
For example, an acid generator having a base-dissociable group is dissolved in a solvent, and an alkali developer is added thereto and mixed. Thereby, the base dissociable group can be converted into an alkali-soluble group (hydroxy group or carboxy group). Examples of the method for confirming the alkali-soluble group include acidity measurement, NMR measurement and MS measurement of the produced compound.
As the solvent, dimethylformamide and dimethyl sulfoxide are preferable.
As the alkali, tetramethylammonium hydroxide is preferable.

  The acid generator (B) is represented by the following formula (II-a) or (II-b), each containing a group represented by the formula (Ba) or a group represented by the formula (Bb). An acid generator is preferred.

[In formula (II-a) or formula (II-b),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a single bond or a divalent alkanediyl group having 1 to 17 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—.
Y represents a C 3-18 divalent alicyclic hydrocarbon group, and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O— or —CO—. .
R ^{3 to} R ⁶ represent the same meaning as described above.
Z ⁺ represents an organic cation. ]

In the formula (II-a) and the formula (II-b), 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 perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like can be given.
Q ¹ and Q ² are preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

As the alkanediyl group of L ¹ , a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group , A straight-chain alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group.

Examples of the group in which —CH ₂ — contained in the alkanediyl group of L ¹ is replaced by —O— or —CO— are represented by any of the following formulas (b1-1) to (b1-7): Group. , Formula (b1-1) to Formula (b1-7) are described in accordance with Formula (II-a) and Formula (II-b) on the left and right sides, and each of the two bonds represented by * Among them, the bond on the left side is bonded to the carbon atom of C (Q ¹ ) (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 alkanediyl group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent alkanediyl group having 1 to 12 carbon atoms.
L ^b4 represents a divalent alkanediyl 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 alkanediyl group having 1 to 15 carbon atoms.
L ^b6 represents a single bond or a divalent alkanediyl group having 1 to 15 carbon atoms.
L ^b7 represents a divalent alkanediyl 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 alkanediyl group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent an alkanediyl group having 1 to 11 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
L ^b11 represents a single bond or a divalent alkanediyl group having 1 to 13 carbon atoms.
L ^b12 represents a divalent alkanediyl group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b11 and L ^b12 is 14.

Among them, L ¹ is preferably a group represented by any one of formulas (b1-1) to (b1-4), and more preferably represented by formula (b1-1) or formula (b1-3). More preferably a divalent group represented by formula (b1-1). In particular, a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, that is, * —CO—O— (CH ₂ ) _u — (u is 0 Represents an integer of ˜6, and * is preferably a bond with —C (Q ¹ ) (Q ² ) —, and is represented by the formula (b1-1) which is a single bond or a methylene group. Are more preferable, that is, * —CO—O— and * —CO—O—CH ₂ —.

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

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

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

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

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

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

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

The divalent alicyclic hydrocarbon group for Y is preferably a group represented by the following.

Examples of the group in which —CH ₂ — contained in the divalent alicyclic hydrocarbon group is replaced by —O— or —CO— include groups represented by the following.
Y is preferably a polycyclic alicyclic hydrocarbon group, more preferably a polycyclic alicyclic hydrocarbon group containing an adamantane ring.

Examples of the salt represented by the formula (II-a) include the following salts.

Examples of the salt represented by the formula (II-b) include the following salts.

Z ^{+ in} formula (II-a) and formula (II-b) includes organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. . Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and any of the following formulas (b2-1), (b2-2), (b2-3), and (b2-4) is more preferable. It is an organic cation represented by

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represents a hydrocarbon group having 1 to 30 carbon atoms, and this hydrocarbon group is an alkyl group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms. And an aromatic hydrocarbon group having 6 to 18 carbon atoms. The alkyl group may have a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group includes a halogen atom and a carbon number. The aromatic hydrocarbon group may have 2 to 4 acyl groups or glycidyloxy groups, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or an alicyclic group having 3 to 18 carbon atoms. You may have a hydrocarbon group or a C1-C12 alkoxy group. R ^b4 and R ^b5 may be combined to form a ring that may have a hetero atom.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represents an integer of 0 to 5, and when m2 is 2 or more, a plurality of R ^b7 may be the same or different. When n2 is 2 or more, a plurality of R ^b8 is It may be the same or different.
R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or R ^b9 and R ^b10 are a sulfur atom to which they are bonded. Together with each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with —CH—CO— to which they are bonded. The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
R ^b12 represents an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aromatic hydrocarbon group has It may be substituted with an alkyl group having 1 to 12 carbon atoms, 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.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently 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 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When q2 is 2 or more, the plurality of R ^b15 is When r2 is 2 or more, a plurality of R ^b16 may be the same or different. When s2 is 2 or more, a plurality of R ^b17 may be the same or different, and t2 is 2 or more. Sometimes, the plurality of R ^b18 may be the same or different.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. .
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups. * Represents a bond with an adamantane ring or a cyclohexane ring.
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 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 halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The alkyl group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms, and in particular, a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group , A pentyl group, a hexyl group, an octyl group and a 2-ethylhexyl group are preferred.
The alicyclic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms, and in particular, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl. Group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group and isobornyl group are preferable.
The aromatic hydrocarbon group for R ^b12 includes a phenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-cyclohexylphenyl group, a 4-methoxyphenyl group, a biphenylyl group, and A naphthyl group and the like are preferable.
A group in which an aromatic hydrocarbon group of R ^b12 and an alkyl group are bonded is typically an aralkyl group.

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 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.

The ring containing a sulfur atom which R ^b4 and R ^b5 may form together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. If it contains one or more sulfur atoms, it may further contain one or more sulfur atoms and / or one or more oxygen atoms. As the ring, a ring having 3 to 18 carbon atoms is preferable, and a ring having 4 to 13 carbon atoms is more preferable.

Among the exemplified organic cations, the cation (b2-1) is preferable, and an organic cation represented by the following formula (b2-1-1) [hereinafter, referred to as “cation (b2-1-1)” may be used. ] Is more preferable, and triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (in formula (b2-1-1), v2 = w2 = 0, x2 = 1 and R ^b21 is a methyl group) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R More preferably, ^b21 is a methyl group.
In formula (b2-1-1),
R ^{b19 to} R ^b21 are each independently a halogen atom (more preferably a fluorine atom) hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alicyclic group having 3 to 18 carbon atoms. Represents a hydrocarbon group. It is also possible to form two of which may have a hetero atom together ring selected from R ^b19 to R ^b21.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different, when w2 is 2 or more, the plurality of R ^b20 are the same or different, and when x2 is 2 or more, the plurality of R ^b21 are the same or different. .

Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alicyclic ring having 4 to 18 carbon atoms. It is a group containing a formula hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms.

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

Examples of the cation (b2-2) include the following cations.
Examples of the cation (b2-3) include the following cations.

  Moreover, the cation described in Unexamined-Japanese-Patent No. 2010-204646 may be sufficient as a cation.

  The acid generator represented by the formula (II-a) or the formula (II-b) is a combination of a sulfonate anion and an organic cation. These sulfonate anions and organic cations can be arbitrarily combined. Specific examples of the acid generator represented by the formula (II-a) or the formula (II-b) are shown in Table 1 below. In Table 1 below, a salt represented by the formula (b1-s-1) is represented as “(b1-s-1)” according to the formula number, and the formula (b2-c- The organic cation represented by 1) is represented as “(b2-c-1)” or the like according to the formula number.

More preferable acid generators (B) include the following salts.

The acid generator (B) can be produced by the following production method or a method analogous thereto.
For example, a salt represented by the formula (II-a) is obtained by reacting a compound represented by the formula (II-aa) and a compound represented by the formula (II-ab) under a basic catalyst. It can manufacture by making it react. Examples of the solvent include chloroform. Examples of the base catalyst include N-methylpyrrolidine.
[Wherein, X ¹ represents a halogen atom or —O—CO—R ¹ . Other symbols are as defined above. ]

Examples of the compound represented by the formula (II-aa) include compounds described in JP-A-2006-257078.
Examples of the compound represented by the formula (II-ab) include heptafluorobutyryl chloride.

  The acid generator represented by the formula (II-a) or the acid generator represented by the formula (II-b) may be used singly or in combination, or both may be used simultaneously.

The resist composition of the present invention may contain a known acid generator (hereinafter sometimes referred to as “other acid generator”) in addition to the acid generator (B).
Other acid generators are classified into nonionic and ionic types, and any of them may be used in the resist composition of the present invention.
Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, and JP-A 63-163452. No. 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, etc. It is possible to use a compound that generates an acid by radiation.

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

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y ′ represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the alkyl group and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z1 ⁺ represents an organic cation. ]

The perfluoroalkyl group Q ^b1 and ^{Q b2,} are the same as those of the perfluoroalkyl group of Q ¹ and Q ² in the above-mentioned formula (II-a) and formula (II-b).
Q ^b1 and Q ^b2 are preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and among these groups, Two or more types may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, etc.) is added to the linear alkanediyl. Those having a side chain, for example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4- Branched alkanediyl groups such as diyl groups, 2-methylbutane-1,4-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 —CH ₂ — contained in the saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include formula (b1-1 ′) to formula (b1-6 ′). The expressions (b1-1 ′) to (b1-6 ′) are described in accordance with the expression (B1) on the left and right, and among the two bonds represented by *, C (Q ^b1 ) (Q ^b2 )-and, on the right side, -Y '. The same applies to specific examples of the following formulas (b1-1 ′) to (b1-6 ′).

In formula (b1-1 ′) to formula (b1-6 ′),
L ^{b2 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^{b3 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^{b4 ′} represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the 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 ′} and L ^{b7 ′} each independently represent a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the 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 ′} and L ^{b10 ′} each independently represent a divalent saturated hydrocarbon group having 1 to 11 carbon atoms. However, the upper limit of the carbon number of L ^{b9 ′} and L ^{b10 ′} is 12.
Among them, L ^b1 is preferably any one of formula (b1-1 ′) to formula (b1-4 ′), more preferably formula (b1-1 ′) or formula (b1-2 ′), A divalent group represented by the formula (b1-1 ′) is preferable. Particularly preferred is a divalent group represented by the formula (b1-1 ′) wherein L ^{b2 ′} is a single bond or —CH ₂ —.

Examples of the divalent group represented by formula (b1-1 ′) to formula (b1-5 ′) and formula (b1-7 ′) include the formula (b1-1) to formula (b1-5) and The thing similar to the bivalent group of a formula (b1-7) is mentioned.
Examples of the divalent group represented by the formula (b1-6 ′) include the following in addition to the divalent group represented by the formula (b1-6).

As the alkyl group for Y ′, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, Examples thereof include alkyl groups such as 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and preferably an alkyl group having 1 to 6 carbon atoms.
Examples of the alicyclic hydrocarbon group include groups represented by the following formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — in the alicyclic hydrocarbon group of Y ′ is replaced by —O—, —SO ₂ — or —CO— include groups represented by formula (Y12) to formula (Y26). Is mentioned.

  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 alkyl group of Y ′ and the alicyclic hydrocarbon group include, for example, 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, C3-C16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl Group, 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 Represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4). The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group and the like, which are substituents for Y ′, may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.

Examples of the halogen atom, aromatic hydrocarbon group, aralkyl group, and acyl group are the same as described above.
Examples of the hydroxy group-containing aliphatic hydrocarbon group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group and the like.
Examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl group, naphthylethyl group and the like.

Examples of Y ′ include the following.

In addition, when Y ′ is an alkyl group and L ^b1 is a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, the methylene group of the divalent aliphatic hydrocarbon group bonded to Y ′ is And is preferably replaced by an oxygen atom or a carbonyl group. In this case, the methylene group constituting the alkyl group of Y ′ is not replaced with an oxygen atom or a carbonyl group.

Y ′ is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl which may have a substituent (for example, an oxo group). More preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.
Y ′ preferably does not contain a structure that is cleaved by the action of an alkali developer.

The sulfonate anion in the salt represented by the formula (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).
The sulfonate anion in the salt represented by the formula (B1) may be an anion described in JP 2010-204646 A.

  Examples of the organic cation contained in the acid generator (B1) include the same organic cations contained in the formula (II-a) or the formula (II-b) described above.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, and preferably a combination of any one of anion (b1-1-1) to anion (b1-1-9) and cation (b2-1-1) and anion A combination of any of (b1-1-3) to (b1-1-5) and a cation (b2-3) can be mentioned.

  The acid generator (B1) is preferably a salt represented by the formula (B1-1) to the formula (B1-20), more preferably an acid containing a triphenylsulfonium cation or a tolylsulfonium cation. Generator (B1-1), (B1-2), Formula (B1-3), (B1-6), Formula (B1-7), (B1-11), (B1-12), (B1-13) ) And (B1-14).

In the resist composition of the present invention, when only the acid generator (B) is contained as the acid generator, the content of the acid generator (B) is preferably 1 mass with respect to 100 parts by mass of the resin (A). Part 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).
Moreover, when it contains other acid generators, such as an acid generator (B1), the total content of an acid generator (B) and another acid generator is 100 mass parts of resin (A). And 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).
When the resist composition contains the acid generator (B) and other acid generators, the ratio (mass) of the content of the acid generator (B) and other acid generators is, for example, 5:95 to 95: 5, preferably 10:90 to 90:10, more preferably 15:85 to 85:15.

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

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may be used individually by 1 type, and may use 2 or more types together.

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

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

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

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

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

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

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

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

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

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

  The content of the basic compound (C) in the solid content of the resist composition is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably 0.8. It is about 01 to 1% by mass.

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

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A) containing a resin (A1) and a resin (A2), an acid generator (B), a solvent (E) used as necessary, other acid generators, a base It can prepare by mixing a sex compound (C) and other ingredients (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (E), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

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

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking) or using a decompression device to form a composition layer from which the solvent has been removed. The temperature in this case is preferably about 50 to 200 ° C., for example. The pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

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

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using an alkali developer using a developing device.
The alkaline developer used here 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).
After development, it is preferable to rinse with ultrapure water to remove water 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 composition ratio of the resin (A) (copolymerization ratio of the structural unit derived from each monomer used for the production of the resin (A) to the resin (A)) is the amount of unreacted monomer in the reaction liquid after the polymerization is finished. It measured using the chromatography, and computed by calculating | requiring the monomer amount used for superposition | polymerization from the obtained result. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

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

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

  A salt represented by the formula (II-1-a) was synthesized by the method described in Example 2 of JP-A-2006-257078. A salt represented by the formula (II-1-a) (3.00 parts), chloroform (30.00 parts) and N-methylpyrrolidine (0.85 part) were charged, and the mixture was stirred at 0 ° C. for 30 minutes. Thereafter, 1.74 parts of the compound represented by the formula (II-1-b) were charged therein, and the mixture was stirred at 0 ° C. for 3 hours. To the obtained reaction product, 150 parts of chloroform and 40 parts of a 5% oxalic acid aqueous solution were charged, stirred and separated. The recovered organic layer was charged with 50 parts of ion-exchanged water, and stirred and separated. This water washing was performed 5 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, 10 parts of acetonitrile was added to dissolve the resulting concentrate, the mixture was concentrated, 20 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 20 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 2.19 parts of the salt represented by the formula (II-1).

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 535.1

Synthesis Example 3: Synthesis of salt represented by formula (II-9)

  A salt represented by the formula (II-9-a) was synthesized by the method described in Example 2 of JP-A-2006-257078. A salt represented by the formula (II-9-a) (3.00 parts), chloroform (30.00 parts) and N-methylpyrrolidine (0.85 parts) were charged, and the mixture was stirred at 0 ° C. for 30 minutes. Thereafter, 1.57 parts of the compound represented by the formula (II-9-b) was added thereto, followed by stirring at 0 ° C. for 3 hours. To the obtained reaction product, 150 parts of chloroform and 40 parts of a 5% oxalic acid aqueous solution were charged, stirred and separated. The recovered organic layer was charged with 50 parts of ion-exchanged water, and stirred and separated. This water washing was performed 5 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, 10 parts of acetonitrile was added to dissolve the resulting concentrate, the mixture was concentrated, 20 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 20 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 1.84 parts of the salt represented by the formula (II-9).

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 435.1

Synthesis Example 4: Synthesis of salt represented by formula (II-45)
10.00 parts of the salt represented by the formula (II-45-a) and 80.00 parts of chloroform were charged and dissolved by stirring. To this, 7.97 parts (purity 97.1%) of a compound represented by the formula (II-45-b) was added, and then 0.15 part of lithium amide was added and stirred at 23 ° C. for 30 minutes. Furthermore, 13.00 parts of molecular sieve (5A; manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the mixture was heated and stirred at 60 ° C. for 8 hours. The solution was cooled to 23 ° C. and filtered, and the filtrate was taken out. To the filtrate, 24.53 parts of ion-exchanged water was added and stirred, followed by liquid separation to recover the organic layer. The recovered organic layer was washed twice with water. To the organic layer after washing, 1.33 parts of activated carbon was added, stirred and filtered to collect the filtrate. The filtrate was concentrated to obtain 20.20 parts of pale yellow oil. To 20.20 parts of the obtained pale yellow oil, 60.60 parts of acetonitrile was added and dissolved, and concentrated. Further, 81.80 parts of ethyl acetate was added thereto. The obtained solution was concentrated, 76.60 parts of methyl-tert-butyl ether was added, and this was stirred. Then, since it isolate | separated into two layers, the supernatant liquid was removed, the lower layer was taken out, and this was concentrated. To the obtained concentrated liquid, 66.00 parts of ethyl acetate was added and stirred. Since it was separated into two layers, the supernatant was removed, the lower layer was taken out and concentrated to obtain 11.96 parts of the salt represented by the formula (II-45-c).
A mixed solution of 6.60 parts of the salt represented by the formula (II-45-c), 40.00 parts of chloroform, 7.70 parts of 1N hydrochloric acid aqueous solution and 7.70 parts of methanol was charged and stirred at 23 ° C. for 15 hours. . Thereafter, 40.00 parts of a 1N aqueous sodium hydrogen carbonate solution was added, and this was stirred and then separated. 40.00 parts of ion-exchanged water was charged, and this was stirred and separated. The operation of washing the organic layer with water was performed three times. To the organic layer after washing, 1.00 part of activated carbon was added, stirred and filtered to collect the filtrate. The filtrate was concentrated to obtain 7.71 parts of a salt represented by the formula (II-45-d) as a pale yellow oil.
3.09 parts of a salt represented by the formula (II-45-d), 15.50 parts of acetonitrile and 0.89 parts of carbonyldiimidazole were charged and stirred at 50 ° C. for 2 hours. Thereafter, the mixture was cooled to 40 ° C., a solution prepared by dissolving 1.00 parts of the compound represented by the formula (II-45-e) in 9.00 parts of acetonitrile was added dropwise, and reacted at 40 ° C. for 3 hours. After the reaction, the reaction mixture was cooled, 30 parts of chloroform and 30 parts of ion exchange water were added, and the mixture was stirred and separated. The organic layer was washed repeatedly with 30 parts of ion exchanged water until the aqueous layer became neutral. 1.00 part of activated carbon was added to the organic layer, stirred and filtered. The filtrate was concentrated, 10 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the residue, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The residue was dissolved in chloroform and concentrated to obtain 2.24 parts of the salt represented by the formula (II-45).

MS (ESI (+) Spectrum): M + 263.1
MS (ESI (-) Spectrum): M-535.1

Resin synthesis Monomers used in resin synthesis are shown below.

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

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

[Synthesis of Resin A2-1]
Monomer (D), monomer (E), monomer (K), monomer (C) and monomer (F) are mixed in a molar ratio [monomer (D): monomer (E): monomer (K): monomer (C): The monomer (F)] was mixed so as to be 50: 5: 4: 33: 8, and 1.2 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.8 mol% and 5.4 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 4.7. × 10 ³ of the resin A2-1 (copolymer) was obtained in 71% yield. This resin A2-1 has the following structural units. The molar ratio of each structural unit is as follows: monomer (D): monomer (E): monomer (B): monomer (C): monomer (F) = 40.6: 5.1: 4.8: 39.7: 9 .8.

[Synthesis of Resin A2-2]
Monomer (A), monomer (E), monomer (B), monomer (C), and monomer (F) are in a molar ratio [monomer (A): monomer (E): monomer (B): monomer (C): Monomer (F)] was mixed at 45: 5: 9: 33: 8, and 1.2 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 2.0 mol% and 6.0 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 4.2. × 10 ³ of the resin A2-2 (copolymer) was obtained in 80% yield. This resin A2-2 has the following structural units. The molar ratio of each structural unit is as follows: monomer (A): monomer (E): monomer (B): monomer (C): monomer (F) = 35.2: 5.4: 9.8: 39.8: 9 .8.

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

[Synthesis of Resin A2-4]
Monomer (D), monomer (E), monomer (B), monomer (C) and monomer (F) are mixed in a molar ratio [monomer (D): monomer (E): monomer (B): monomer (C): The monomer (F)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. × give 10 ³ of copolymer in 60% yield. This copolymer has the following structural units respectively derived from the monomer (D), the monomer (E), the monomer (B), the monomer (F) and the monomer (C). 4.

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

[Synthesis of Resin A2-6]
Monomer (D), monomer (L), monomer (K), monomer (C), and monomer (F) are mixed so as to be 35: 15: 3: 27: 20, and the total amount of monomers is 1.5 mass. Double dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.9. × give 10 ³ of copolymer in 73% yield. This copolymer has the following structural units and is designated as resin A2-6.

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

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

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

<Resin>
A1-1, A1-2, A2-1 to A2-6, X1, X2 synthesized by resin synthesis

<Acid generator>
II-1: Salt represented by formula (II-1) synthesized in the above synthesis example
50 mg of the acid generator II-1 was dissolved in 0.7924 g of dimethyl sulfoxide, 0.25 g of an aqueous 2.38 mass% tetramethylammonium hydroxide solution was added, and the mixture was stirred at 23 ° C. for 1 hour, and then the acid generator II- When the decomposition product of 1 was confirmed, it was confirmed that the base dissociable group was cleaved and the following compound was produced.

II-9:
50 mg of the acid generator II-9 was dissolved in 0.7924 g of dimethyl sulfoxide, and 0.25 g of an aqueous 2.38 mass% tetramethylammonium hydroxide solution was added and stirred at 23 ° C. for 1 hour, and then the acid generator. When the decomposition product of II-9 was confirmed, it was confirmed that the base dissociable group was cleaved and the following compound was produced.

II-45:
50 mg of the acid generator II-45 was dissolved in 0.7924 g of dimethyl sulfoxide, and 0.25 g of an aqueous 2.38 mass% tetramethylammonium hydroxide solution was added and stirred at 23 ° C. for 1 hour, and then the acid generator. When the decomposition product of II-45 was confirmed, it was confirmed that the base dissociable group was cleaved and the following compound was produced.

B1: Synthesis according to the example of JP 2010-152341 A
50 mg of the acid generator B1 was dissolved in 0.7966 g of dimethyl sulfoxide, 0.25 g of an aqueous 2.38 mass% tetramethylammonium hydroxide solution was added, and this solution was confirmed after stirring at 23 ° C. for 1 hour. A decomposition product of the acid generator B1 could not be confirmed.

B2: synthesized according to examples of WO2008 / 99869 and JP2010-26478
50 mg of acid generator B2 was dissolved in 0.7998 g of dimethyl sulfoxide, 0.25 g of an aqueous 2.38 mass% tetramethylammonium hydroxide solution was added, and the mixture was stirred at 23 ° C. for 1 hour. Decomposition of the acid generator B2 could not be confirmed.

B3: synthesized according to the example of JP-A-2005-221721
50 mg of the acid generator B3 was dissolved in 0.7981 g of dimethyl sulfoxide, 0.25 g of an aqueous 2.38 mass% tetramethylammonium hydroxide solution was added, and this solution was confirmed after stirring at 23 ° C. for 1 hour. A decomposition product of the acid generator B3 could not be confirmed.

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

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

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

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

<Evaluation of CD uniformity (CDU)>
In terms of effective sensitivity, the hole diameter of a pattern formed with a mask having a hole diameter of 70 nm was measured 24 times per hole, and the average value was taken as the average hole diameter of one hole. A standard deviation is obtained using a population obtained by measuring 400 average hole diameters of a pattern formed with a mask having a hole diameter of 70 nm in the same wafer,
When the standard deviation is less than 1.85 nm,
When the standard deviation is 1.85 nm or more and less than 2.00 nm, “◯”,
The case where the standard deviation was 2.00 nm or more was judged as “x”.
The results are shown in Table 3. Numerical values in parentheses indicate standard deviation (nm).

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

  According to the resist composition of the present invention, CD uniformity (CDU) at the time of producing a resist pattern is good, and the number of occurrences of defects can be reduced when a resist pattern is formed.

Claims (6)

(A1) a resin having a structural unit represented by formula (I),
(A2) A resist composition containing a resin that is insoluble or hardly soluble in an alkaline aqueous solution and that can be dissolved in an alkaline aqueous solution by the action of an acid, and (B) an acid generator,
The acid generator is represented by a group represented by the formula (Ba) or a formula (Bb) as a group having a structure that is cleaved by the action of an alkaline developer capable of developing the resist composition at least in an anion. A resist composition which is an acid generator having a group .
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]
[In Formula (Ba), R ³ represents a C 1-6 alkyl group having a fluorine atom. ]
[In formula (Bb), R ⁴ represents a C 1-6 alkyl group having a fluorine atom.
R ⁵ and R ⁶ each independently represents a hydrogen atom or a fluorine atom. ] The resist composition according to claim 1, wherein R ² is a fluorinated alkyl group having 1 to 6 carbon atoms. The resist composition according to claim 1, wherein A ¹ is a methylene group. Acid generator having a structure that is cleaved by the action of an alkali developing solution, according to claim 1 to 3 is an acid generator represented by the formula acid generator or the formula represented by (II-a) (II- b) The resist composition according to any one of the above.
[In formula (II-a) or formula (II-b),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a single bond or a divalent alkanediyl group having 1 to 17 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—.
Y represents a C 3-18 divalent alicyclic hydrocarbon group, and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O— or —CO—. .
R ^{3 to} R ⁶ represent the same meaning as described above.
Z ⁺ represents an organic cation. ] Furthermore, the resist composition in any one of Claims 1-4 containing a solvent. (1) The process of apply | coating the resist composition 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.