JP5990021B2 - 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

  In a resist pattern manufactured from a conventional resist composition, the exposure margin and the mask error factor may not always be sufficiently satisfied, or many defects may occur.

The present invention includes the following inventions.
[1] (A1) a resin having a structural unit represented by formula (I),
(A2) a resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid;
(B) an acid generator ,
( D) a compound represented by the formula (II1) and
(E) A resist composition containing a solvent .
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]
[In the formula (II1),
R ⁶ is an alkyl group having 1 to 4 carbon atoms, represents an alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 14 carbon atoms having 3 to 18 carbon atoms, contained in the alicyclic hydrocarbon group The hydrogen atom is substituted with a hydroxy group, a hydroxyalkyl group having 1 to 4 carbon atoms, a fluorinated hydroxyalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an acyloxy group having 2 to 5 carbon atoms. The hydrogen atom contained in the aromatic hydrocarbon group may be a fluorine atom, a chlorine atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 2 carbon atoms. -CH _2- which may be substituted with an acyl group having 5 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms or a phenyl group, -O -, - CO-, or -SO ₂ - in It may be replaced.
X ¹ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms , and —CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—.
X ² represents —O— or —N (R ^d ) —.
R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aromatic hydrocarbon group having 6 to 14 carbon atoms. ]
[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 an ethylene group.
[4] (1) The process of apply | coating the resist composition in any one of said [1]-[3] on a board | substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern including a step of developing the composition layer after heating.

  According to the resist composition of the present invention, it is possible to obtain a resist pattern that has an excellent exposure margin and mask error factor and has few defects.

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)”),
(B) an acid generator (hereinafter sometimes referred to as “acid generator (B)”) ,
(D) a compound represented by the formula (II1) and
(E) It contains a solvent (hereinafter sometimes referred to as “solvent (E)”) .
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 alkaline aqueous solution. Dissolvable resin (hereinafter sometimes referred to as “resin (A2)”) .

<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 includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclodecyl group, a 2-alkyl-2-adamantyl group, and a 1- (1-adamantyl) -1-alkyl group. And isobornyl groups.

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, Bae Le fluoromethyl group, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1, 1,1,2,2-pentafluoro-propyl 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, Examples thereof include fluorinated alkyl groups such as a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

In formula (I), A ¹ is preferably an ethylene group.
R ² is 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 (III) And structural units derived from known monomers used in the art. A structural unit represented by the formula (III) is preferable.
[In the formula (III) ,
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.
Examples of R ¹² include the following groups.

As the structural unit represented by the formula (III), the structural unit represented by the following is preferable.
In the above 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 (III).
Among these, a structural unit represented by the formula (III-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 resin (A1) has structural unit (III) , the content rate of structural unit (III) in resin (A1) has the range of 1-95 mol% with respect to all the structural units of 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 an excellent exposure margin and a mask error factor and generating few defects can be manufactured.
Resin (A1) having structural units (I) and / or (III) in such a content ratio is compound (I ′), structural unit (III) 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.
The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 7,000 or more) and 15,000 or less (more preferably 10,000 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) can be obtained by polymerizing one or more monomers (a1) having an acid-labile group described later. In addition, as long as the resin (A2) has the above-described properties, the resin (A2) is a structural unit derived from a monomer having no acid-labile group (hereinafter sometimes referred to as “acid-stable monomer”), a monomer known in the art The structural unit represented by the structural unit (I) and the formula (III) described above 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 (III) , 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.

<Monomer (a1) having an acid labile group>
An "acid labile group" has a leaving group, when contacted with an acid leaving group and elimination means a group forming a hydrophilic group (e.g., hydroxy group or 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 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 decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.
In Formula (1), the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 1 to 16 carbon atoms, more preferably 3 to 16 carbon atoms.

In the —C (R ^a1 ) (R ^a2 ) (R ^a3 ) group, examples of the divalent hydrocarbon group formed by combining R ^a1 and R ^a2 include the following groups. The carbon number of the divalent hydrocarbon group is preferably 3 to 12 carbon atoms.

In Formula (1), the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 1 to 16 carbon atoms, more preferably 3 to 16 carbon atoms.
Examples of the acid labile group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), 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- (Adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group 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 , p -methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl, anthryl 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 the formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups.

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

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

  As the (meth) acrylic monomer having an acid labile group and an alicyclic hydrocarbon group, a monomer represented by the formula (a1-1) or a monomer represented by the formula (a1-2) is preferably used. Can be 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.
n2 represents an integer of 0 or 1 . ]

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.

Examples of the monomer represented by the formula (a1-1) include monomers described in JP 2010-204646 A. 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 represented by the formula (a1-2) include 1-ethyl-1-cyclopentyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, 1-ethyl-1-cycloheptyl (meta ) Acrylate, 1-methyl-1-cyclopentyl (meth) acrylate, 1-isopropyl-1-cyclopentyl (meth) acrylate, and the like. Monomers are preferably monomers represented by the formula (a1-2-1) ~ (a1-2-6), more preferably monomers represented by the formula (a1-2-3) ~ (a1-2-4) A monomer represented by the following formula (a1-2-3) is more preferable.

  When the resin (A2) contains the structural unit (a1-1) or the structural unit (a1-2), the total content thereof is usually 10 to 95 mol% with respect to all the structural units of the resin (A2). Yes, preferably 15 to 90 mol%, more preferably 20 to 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 hydroxyl group which is a hydroxystyrene. An acid stable monomer having 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 a monomer (a1) having an acid labile group and an acid stable monomer, the structural unit derived from the monomer (a1) having an acid labile group is: Preferably it is 10-80 mol% with respect to 100 mol% of all structural units, More preferably, it is 20-60 mol%.
The content of the structural unit derived from the monomer having an adamantyl group (particularly the structural unit (a1-1)) is preferably 15 mol% or more based on the total of the structural units derived from the acid labile monomer (a1). is there. When the ratio of the structural unit derived from the monomer having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

  The resin (A2) is preferably a copolymer of an acid labile monomer (a1) and an acid stable monomer. In this copolymer, the acid labile monomer (a1) is more preferably at least one of the monomer (a1-1) having an adamantyl group and the monomer (a1-2) (preferably the monomer having a cyclohexyl group or a cyclopentyl group). One type (more preferably a monomer (a1-1) having an adamantyl 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 contained at 2:10, particularly preferably 0.2: 10 to 1:10 (mass ratio).

<Resin other than resin (A1) and (A2)>
The resist composition of the present invention includes resins other than the resins (A1) and (A2) described above, for example, structural units derived from the acid labile monomer (a1) described above, structural units derived from the acid stable monomer, and the like. Further, a resin composed of a structural unit derived from a known monomer used in the field may be contained.
When the resist composition of this invention contains resin other than resin (A1) and (A2), these content rates are normal with respect to the total amount of resin (A) contained in the resist composition of this invention. It is 0.1-50 mass%, Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%.
In the resist composition of the present invention, the content of the resin (A) is preferably 80% by mass or more 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) is classified into a nonionic type and an ionic type, 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). -Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

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

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents 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 the above —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, A perfluorohexyl group etc. are mentioned.
In formula (B1), Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, 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, 17-diyl group, main Chiriden group, ethylidene group, propylidene group, 2-propylidene linear alkanediyl group such 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-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-propylene group Branched alkanediyl such as butylene group, 2-methyl-1,4-butylene group;
Monocyclic alicyclic hydrocarbons that are cycloalkanediyl groups such as 1,3-cyclobutylene group, 1,3-cyclopentylene group, 1,4-cyclohexylene group, 1,5-cyclooctylene group, etc. Group;
Examples thereof include polycyclic alicyclic hydrocarbon groups such as 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group 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). L ^b1 is preferably any one of formulas (b1-1) to (b1-4), more preferably formula (b1-1) or formula (b1-2). Incidentally, the formula (b1-1) ~ formula (b1-6) are described together the left and right in the equation (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side Combines with -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 saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a 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 saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a 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 saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent a 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, a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ — is more preferable. It is a group.

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 alkyl group for Y include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, 2 -Alkyl groups, such as an ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, are mentioned, Preferably, a C1-C6 alkyl group is mentioned.
Examples of the alicyclic hydrocarbon group include groups represented by the following formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— are represented by formulas (Y12) to (Y26). Groups.

  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 of the alkyl group and alicyclic hydrocarbon group in Y 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, carbon 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 carbon Represents an aromatic hydrocarbon group of formula 6 to 18. j2 represents an integer of 0 to 4. The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are 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 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthranyl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group; a tolyl group, a xylyl group, a cumenyl group, and a mesityl group. , Aryl groups such as biphenyl group, anthryl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl group, naphthylethyl group and the like.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.
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 oxygen It is preferably replaced by an 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 adamantyl group which may have a substituent (for example, an oxo group or the like), more preferably an adamantyl group or an oxoadamantyl group.

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 formulae, the definition of the substituent has the same meaning as described above, and the substituents R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

  The cation contained in the acid generator (B) includes an onium cation, such as a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation, and preferably a sulfonium cation or an iodonium cation, More preferred is an arylsulfonium cation.

Z ⁺ in formula (B1) is preferably represented by any of formula (b2-1) to formula (b2-4).

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 .
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.
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 ^b9 and R ^b10 may be bonded to each other together with the sulfur atom to which they are bonded to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring), and R ^b11 and R ^b12 are , And -CH-CO- to which they are bonded may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) .
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 .

The A alkyl group, include methyl group, ethyl group, n- propyl group, an isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, a pentyl group, a hexyl group, octyl group and 2-ethylhexyl group It is done. 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 saturated hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups. * Represents a bond with an adamantane ring or a cyclohexane ring.
As aromatic hydrocarbon group, phenyl group, naphthyl group, anthranyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Groups, anthryl 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.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, and the cation represented by the formula (b2-1-1) is more preferable. is a triphenyl sulfonium cation (in the formula (b2-1-1), v2 = w2 = x2 = 0).

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, and the alkyl group, alkoxy group and alicyclic hydrocarbon group are a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a carbon number. It may be substituted with 2 to 4 acyl groups or glycidyloxy groups. 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 these, R ^{b19 to} 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 alkoxy group having 1 to 12 carbon atoms.

  Specific examples of the cation include those described in JP2010-204646A.

  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 A combination of any one of anions (b1-1-3) to (b1-1-5) and a cation (b2-3) may be mentioned.

As the acid generator (B1), preferably, include a salt represented by the formula (B1-1) ~ formula (B1-20), more preferably, triphenylsulfonium mosquito acid generator containing thio emissions (B1 -1), (B1-2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14).

The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part or less).
In the resist of the present invention, the acid generator (B) may contain a single type or a plurality of types of acid generators.

<Compound represented by formula (II)>
The compound represented by the formula (II) is usually used as a quencher.
[In the formula (II1),
R ⁶ is an alkyl group having 1 to 4 carbon atoms, represents an alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 14 carbon atoms having 3 to 18 carbon atoms, contained in the alicyclic hydrocarbon group The hydrogen atom is substituted with a hydroxy group, a hydroxyalkyl group having 1 to 4 carbon atoms, a fluorinated hydroxyalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an acyloxy group having 2 to 5 carbon atoms. The hydrogen atom contained in the aromatic hydrocarbon group may be a fluorine atom, a chlorine atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 2 carbon atoms. -CH _2- which may be substituted with an acyl group having 5 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms or a phenyl group, -O -, - CO-, or -SO ₂ - in It may be replaced.
X ¹ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms , and —CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—.
X ² represents —O— or —N (R ^d ) —.
R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aromatic hydrocarbon group having 6 to 14 carbon atoms. ]

In the formula (II1), examples of the alkyl group of R ³ , R ⁴ , R ⁵ , R ⁶ and R ^d include a methyl group, an ethyl group, a propyl group, a butyl group, a tert-butyl group, and a sec-butyl group. It is done.
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 decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.
Aromatic hydrocarbon groups include phenyl, naphthyl , p -methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl, anthryl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

The hydroxyalkyl group, arsenate Dorokishimechiru group, 2-hydroxyethyl group, 2-hydroxypropyl, 3-hydroxypropyl group, 2,3-dihydroxypropyl group, 4-hydroxybutyl group, 3,4-dihydroxy-butyl group, etc. Is mentioned.
The fluorinated hydroxyalkyl group, if example embodiment, hydroxy difluoromethyl group, a hydroxy-fluoroethyl group, dihydroxy fluoroethyl group, a hydroxy-fluoropropyl group, dihydroxy-fluoropropyl group, hydroxy fluoro isopropyl group, hydroxy fluoro butyl group, hydroxy fluoro sec- Examples thereof include a butyl group, a hydroxyfluoro tert-butyl group, and a dihydroxyfluorobutyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of R ⁶ include groups represented by the following. Among these, R ⁶ is preferably a group having an oxygen atom.

Examples of the alkanediyl group of X ¹ include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. , A straight-chain alkanediyl group such as hexane-1,6-diyl group , 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, Ru include branched alkanediyl, such as 2-methyl-1,4-butylene group.

Examples of the compound represented by the formula (II1) include the following compounds .

Among these, as the compound represented by Formula (II1), R ⁶ is preferably the following compound having an oxygen atom.

The content of the compound represented by the formula (II1) is preferably about 0.01 to 1% by mass based on the solid content of the resist composition.

<Solvent (sometimes referred to as "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>
The resist composition of the present invention may further contain a basic compound different from the basic compound represented by the above formula (II) (hereinafter sometimes referred to as “basic compound (C)”). Good. The basic compound (C) 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 the formula (C1),
R ^c1 , R ^c2 and R ^c3 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. 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, and the aromatic hydrocarbon group The hydrogen atom contained is substituted with 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. It may be. ]

[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.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

[In Formula (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.
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-diphenyl Examples include ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl Ruanirin. Particularly preferred include 2,6-diisopropylaniline.

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

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

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

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

<Preparation of resist composition>
This resist composition is prepared by mixing the resin (A), the acid generator (B), the compound (II) and the solvent (E), optionally a basic compound (C), and other components (F). be able to. 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.

  Thus, each of the resin (A), the acid generator (B), the compound (II), the solvent (E), and the basic compound (C) or component (F) used as necessary is contained in a preferable content. After mixing, the resist composition can be prepared by filtering using a filter having a pore size of about 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises (1) a step of applying the resist composition of the present invention on a substrate, (2) a step of forming a composition layer by removing the solvent from the applied composition, 3) The process of exposing a composition layer, (4) The process of heating the composition layer after exposure, (5) The process of developing the composition layer after a heating is included.

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

The solvent is removed by drying the composition after application. The removal of the solvent is performed, for example, by evaporating the solvent using a heating device such as a hot plate or by using a decompression device to form a composition layer from which the solvent has been removed. As for the temperature in this case, about 50-200 degreeC is illustrated, for example. The pressure is exemplified by about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is exposed. The exposure is usually performed using an exposure machine, and an immersion exposure machine may be used. At this time, exposure is usually performed through a mask corresponding to a required pattern. The exposure light source emits ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser, etc.) Various types of laser beam can be used, such as those that convert the wavelength of the laser beam from) to radiate a harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region.

The composition layer after exposure is subjected to a heat treatment 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 suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for EB, or a resist composition for EUV exposure machines.

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.
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 (D1)]
7.00 parts of a compound represented by the formula (D-1-a) and 70.00 parts of methylene chloride are charged, and the resultant mixed mass is represented by the formula (D-1-b) at 23 ° C. 16.85 parts of a compound (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) was charged and stirred at 23 ° C. for 1 hour. Thereafter, 30 parts of ion-exchanged water was added, stirred and separated. This washing operation was performed 5 times. The obtained organic layer was concentrated to obtain 9.23 parts of a compound represented by the formula (D1).
MASS: 168.1

Synthesis Example 2 [ Synthesis of Compound Represented by Formula (D2)]
10.00 parts of the compound represented by the formula (D-2-a) and 70.00 parts of methylene chloride are charged, and the resultant mixed mass is represented by the formula (D-1-b) at 23 ° C. 9.79 parts of a compound (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred at 23 ° C. for 1 hour. Thereafter, 30 parts of ion-exchanged water was added, stirred and separated. This washing operation was performed 5 times. The obtained organic layer was concentrated, 100 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred, filtered, and dried to obtain 12.05 parts of a compound represented by the formula (D2). .
MASS: 276.2

Synthesis Example 3 [ Synthesis of Compound Represented by Formula (D3)]
10.00 parts of a compound represented by the formula (D-3-a) and 70.00 parts of methylene chloride are charged, and the resulting mixed mass is represented by the formula (D-1-b) at 23 ° C. 18.95 parts of a compound (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) was charged and stirred at 23 ° C. for 1 hour. Thereafter, 30 parts of ion-exchanged water was added, stirred and separated. This washing operation was performed 5 times. The obtained organic layer was concentrated to obtain 10.25 parts of a compound represented by the formula (D3).
MASS: 188.1

Synthesis Example 4 [ Synthesis of Compound Represented by Formula (D4)]
10.00 parts of the compound represented by the formula (D-4-a) and 70.00 parts of methylene chloride are charged, and the resultant mixed mass is represented by the formula (D-1-b) at 23 ° C. 19.15 parts of a compound (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) was charged and stirred at 23 ° C. for 1 hour. Thereafter, 30 parts of ion-exchanged water was added, stirred and separated. This washing operation was performed 5 times. The obtained organic layer was concentrated to obtain 9.81 parts of a compound represented by the formula (D4).
MASS: 187.1

Synthesis Example 5 [ Synthesis of Compound Represented by Formula (D5)]
14.47 parts of a compound represented by the formula (D-5-a) and 100 parts of methylene chloride were charged, and the resulting mass was mixed at 23 ° C. with a compound represented by the formula (D-5-b) ( (Product name: Carbonyldiimidazole, manufactured by Tokyo Chemical Industry Co., Ltd.) 16.85 parts was added and stirred at 23 ° C. for 1 hour, and then 30 parts of ion-exchanged water was added, followed by liquid separation. This washing operation was performed 5 times. The obtained organic layer was concentrated to obtain 13.36 parts of a compound represented by the formula (D5) .

The monomers used in the synthesis of tree fat synthetic resin 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 A2-1]
Monomer (D), monomer (E), monomer (K), monomer (F), and monomer (C) are in a molar ratio [monomer (D): monomer (E): monomer (K): monomer (F): The monomer (C)] 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 (K): monomer (F): monomer (C) = 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 (C) are mixed so that the molar ratio [monomer (A): monomer (B): monomer (C)] is 50:25:25, , 1.5 mass times dioxane was mixed with respect to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. Then, this was heated at 80 ° C. for about 8 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin is filtered and collected, dissolved again in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and collected three times for reprecipitation. 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 derived from the monomer (A), the monomer (B) and the monomer (C), respectively, and is designated as resin A2-3.

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

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

<Preparation of resist composition>
A mixture obtained by mixing and dissolving the components shown in Table 1 was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
Resins A1-1, A2-1 to A2-3, X1 to X2 synthesized in the above synthesis example
<Acid generator>
B1: Synthesis according to the example of JP 2010-152341 A
B2: synthesized according to examples of WO2008 / 99869 and JP2010-26478
B3: synthesized according to the example of JP-A-2005-221721
<Compound represented by Formula (II1)>
D1:
D2:
D3:
D4:
D5:

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

<Manufacture of resist pattern and its evaluation>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying was 110 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature described in the “PB” column of Table 1. An ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 2-poles on axis illumination (σout = 0.97, σin = 0.77, Y-polarized light], the line and space pattern was subjected to immersion exposure by changing the exposure amount stepwise.
After the exposure, post-exposure baking (PEB) was performed on the hot plate at the temperature described in the “PEB” column of Table 1 for 60 seconds.
Further, paddle development was performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution.

  In each resist film, a mask having a pitch of 90 nm and a line of 47 nm was used, and an exposure amount at which the line pattern was 51 nm was defined as an effective sensitivity.

<Evaluation of exposure margin (EL)>
The exposure amount range with an effective sensitivity of ± 10% is plotted on the horizontal axis, and the line width of the mask having a pitch of 90 nm and a line of 47 nm at the exposure amount is plotted on the vertical axis.
The absolute value of the slope of the straight line is
What is 1.1 nm / (mJ / cm ² ) or less, ◎,
1.1nm / (mJ / cm ^{2) beyond, 1.5nm / (mJ / cm 2} ) ○ the following:,
What exceeded 1.5 nm / (mJ / cm < ² >) was set as x.
The results are shown in Table 2. The numerical value in parentheses indicates the absolute value of the slope.

<Mask error factor evaluation (MEF)>
Mask patterns with mask sizes of 48 nm, 50 nm, and 52 nm were formed in terms of effective sensitivity. The mask size is plotted on the horizontal axis, and the line width of the line pattern formed using each mask pattern is plotted on the vertical axis. The slope of the straight line
2.3 or less ◎,
○ over 2.3 and under 3.0
What exceeded 3.0 was set as x.
The results are shown in Table 2. The numbers in parentheses indicate the slope of the straight line.

<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 on the direct hot plate at the temperature shown in the PB column of Table 1.
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].

  According to the resist composition of the present invention, it is possible to obtain a resist pattern that has an excellent exposure margin and mask error factor and has few defects.

Claims (4)

(A1) a resin having a structural unit represented by formula (I),
(A2) a resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid;
(B) an acid generator ,
( D) a compound represented by the formula (II1) and
(E) A resist composition containing a solvent .
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]
[In the formula (II1),
R ⁶ is an alkyl group having 1 to 4 carbon atoms, represents an alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 14 carbon atoms having 3 to 18 carbon atoms, contained in the alicyclic hydrocarbon group The hydrogen atom is substituted with a hydroxy group, a hydroxyalkyl group having 1 to 4 carbon atoms, a fluorinated hydroxyalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an acyloxy group having 2 to 5 carbon atoms. The hydrogen atom contained in the aromatic hydrocarbon group may be a fluorine atom, a chlorine atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 2 carbon atoms. -CH _2- which may be substituted with an acyl group having 5 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms or a phenyl group, -O -, - CO-, or -SO ₂ - in It may be replaced.
X ¹ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms , and —CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—.
X ² represents —O— or —N (R ^d ) —.
R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aromatic hydrocarbon group having 6 to 14 carbon atoms. ] 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. (1) The process of apply | coating the resist composition in any one of Claims 1-3 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.