JP6195725B2 - Resin, resist composition and method for producing resist pattern - Google Patents

Description

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

Patent Document 1 describes a resist composition comprising a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-C), and triphenylsulfonium triflate. ing.
Further, it is known that when a resist pattern is formed from a resist composition by photolithography, a positive resist pattern is obtained when developed with an alkaline developer, and a negative resist pattern is obtained when developed with an organic solvent ( Non-patent document 1).

JP 2000-122294 A

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

  An object of the present invention is to provide a resin suitable for a resist composition capable of producing a resist pattern having excellent line edge roughness (LER).

The present invention includes the following inventions.
[1] A resin comprising a structural unit represented by formula (I), a structural unit represented by formula (II), and a structural unit having an acid labile group.
[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O—, or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]
[In the formula (II),
R ²¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ²¹ represents a divalent linking group.
Ring X ²¹ represents a heterocyclic ring having 2 to 36 carbon atoms.
R ²² is a halogen atom, a hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxyalkyl group having 1 to 24 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a carbon number 2 to 4 acyloxy groups are represented.
m represents an integer of 0 to 10.
When m is 2 or more, the plurality of R ²² are the same or different. ]
[2] The resin according to [1], wherein the structural unit represented by the formula (II) is a structural unit represented by the formula (II-1).
[In the formula (II-1),
R ²¹ and A ²¹ represent the same meaning as described above.
R ^{23 to} R ²⁸ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alkoxyalkyl group having 1 to 24 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a carbon number. Represents a 2 to 4 acyloxy group or a hydrocarbon group having 1 to 24 carbon atoms, or at least two selected from R ^{23 to} R ²⁸ are bonded to each other to form a ring, and the hydrogen atom contained in the ring is , A halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms, —CH ₂ — contained in the ring may be replaced by —CO— or —O—.
t1 represents an integer of 0 to 3.
When t1 is 2 or more, the plurality of R ²³ are the same or different, and the plurality of R ²⁴ are the same or different. ]
[3] A resist composition comprising the resin according to the above [1] or [2] and an acid generator.
[4] The resist composition according to [3], further containing a solvent.
[5] (1) A step of applying the resist composition according to [3] or [4] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition containing the resin of the present invention, a resist pattern having good line edge roughness (LER) can be produced.

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

<Resin of the present invention>
The resin of the present invention (hereinafter sometimes referred to as “resin (A)”) is a structural unit represented by formula (I), a structural unit represented by formula (II), and a structural unit having an acid labile group ( Hereinafter, it may be referred to as “acid-labile structural unit”), and may further contain a structural unit having no acid-labile group.
In the present specification, the “acid labile group” is a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid. Means.

<Structural unit represented by formula (I)>
The resin (A) has a structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”).
[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O—, or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]

Examples of the halogen atom for R ¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group for R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. , Preferably it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom for R ¹ include perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl. A group, a perchloromethyl group, a perbromomethyl group, a periodomethyl group, and the like.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

Examples of the alkanediyl group of A ² and A ³ include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group and hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group, etc. are mentioned.
A ¹ is preferably a single bond or ^* —A ² —CO—O—, more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—. .

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

In the above structural unit, a structural unit in which the 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 and A ¹ represent the same meaning as described above. ]

The compound represented by the formula (I′-1), wherein A ¹ in the compound (I ′) is * —CH ₂ —CO—O— (* represents a bond to —CO—O—), The compound represented by the formula (I′-1-a) and the compound represented by the formula (I′-1-b) can be produced in a solvent. Examples of the solvent used for the reaction include methylene chloride, tetrahydrofuran and acetonitrile.
[Wherein R ¹ represents the same meaning as described above. ]

The compound represented by the formula (I′-1-a) is obtained by reacting the compound represented by the formula (I′-1-c) with the compound represented by the formula (I′-1-d). Can be manufactured.
[Wherein R ¹ represents the same meaning as described above. ]
This reaction is preferably carried out in the presence of a solvent such as methylene chloride, tetrahydrofuran and acetonitrile. In this reaction, a condensing agent such as dicyclohexylcarbodiimide may be used.

Examples of the compound represented by the formula (I′-1-c) include the following compounds.
If a compound having A ¹ and R ¹ corresponding to the desired compound (I ′) is used as the compound represented by the formula (I′-1-c), the target compound (I ′) can be obtained. . The compounds represented by formula (I′-1-c) and formula (I′-1-d) are easily available from the market.

Examples of compound (I ′) include the following.

In the compound (I ′) represented by each of the formulas (aa′-1) to (aa′-6), a compound in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom is also a specific example of the compound (I ′). As an example.

  The content of the structural unit (I) is preferably 1 to 80 mol%, more preferably 2 to 75 mol%, still more preferably 3 to 70 mol% with respect to all the structural units of the resin (A). %, Particularly preferably 5 to 65 mol%.

<Structural unit represented by formula (II)>
The resin (A) has a structural unit represented by the formula (II) (hereinafter sometimes referred to as “structural unit (II)”).
[In the formula (II),
R ²¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ²¹ represents a divalent linking group.
Ring X ²¹ represents a heterocyclic ring having 2 to 36 carbon atoms.
R ²² is a halogen atom, a hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxyalkyl group having 1 to 24 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a carbon number 2 to 4 acyloxy groups are represented.
m represents an integer of 0 to 10.
When m is 2 or more, the plurality of R ²² are the same or different. ]

In the formula (II), as the alkyl group for R ²¹ , methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n- A hexyl group is mentioned, A C1-C4 alkyl group is preferable, A methyl group or an ethyl group is more preferable, A methyl group is further more preferable.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group having a halogen atom include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl. Group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.

As the divalent linking group for A ²¹ , a single bond or * —T ²¹ — (CH ₂ ) _n —CO— (* represents a bond to a carbon atom, and T ²¹ represents —O— or —NH—. And n represents an integer of 1 to 4.). T ²¹ is preferably —O—, and n is preferably 1.
Specifically, A ²¹ is a single bond, * —O—CH ₂ —CO—, * —O— (CH ₂ ) ₂ —CO—, * —O— (CH ₂ ) ₃ —CO—, * — O— (CH ₂ ) ₄ —CO—, * —O— (CH ₂ ) ₅ —CO—, * —O— (CH ₂ ) ₆ —CO—, * —NH—CH ₂ —CO—, * —NH _{- (CH 2) 2 -CO -} , * - NH- (CH 2) 3 -CO -, * - NH- (CH 2) 4 -CO -, * - NH- (CH 2) 5 -CO -, * —NH— (CH ₂ ) ₆ —CO—, (* represents a bond with a carbon atom) and the like.

The heterocyclic ring of the ring X ²¹ may be aromatic or non-aromatic, saturated or unsaturated, but is preferably a non-aromatic heterocyclic ring, more preferably a saturated heterocyclic ring. This heterocyclic ring may be either monocyclic or polycyclic. In addition to the nitrogen atom and the sulfonyl group, this heterocyclic ring may further contain one or more nitrogen atoms, oxygen atoms, sulfur atoms, sulfonyl groups, carbonyl groups, and the like.
The hydrocarbon group for R ²² includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon, an aromatic hydrocarbon group, and combinations thereof.

Examples of the aliphatic hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. And the like, and the like. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
Examples of the group obtained by combining an aliphatic hydrocarbon group and an alicyclic hydrocarbon include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

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 a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, and an n-hexoxy group. .
Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxymethyl group, an n-propoxymethyl group, a methoxyethyl group, an ethoxyethyl group, and an n-propoxyethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
m is preferably 0 to 6, and more preferably 0 to 4.

Examples of the group represented by the formula (IIA) contained in the structural unit (II) include the following groups. * Represents a bond to A ^21.

As the structural unit (II), structural units represented by formulas (II-1) to (II-3) are preferable, and structural units represented by formula (II-2) or formula (II-3) are More preferred is a structural unit represented by the formula (II-3).
[In the formula (II-1),
R ²¹ and A ²¹ represent the same meaning as described above.
R ^{23 to} R ²⁸ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alkoxyalkyl group having 1 to 24 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a carbon number. Represents a 2 to 4 acyloxy group or a hydrocarbon group having 1 to 24 carbon atoms, or at least two selected from R ^{23 to} R ²⁸ are bonded to each other to form a ring, and the hydrogen atom contained in the ring is , A halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms, The methylene group contained in the ring may be replaced with a carbonyl group or an oxygen atom.
t1 represents an integer of 0 to 3.
When t1 is 2 or more, the plurality of R ²³ are the same or different, and the plurality of R ²⁴ are the same or different. ]

[In the formula (II-2),
R ²¹ and A ²¹ represent the same meaning as described above.
R ^{29 to} R ³⁸ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alkoxyalkyl group having 1 to 24 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a carbon number. Represents a 2 to 4 acyloxy group or a hydrocarbon group having 1 to 12 carbon atoms, or at least two selected from R ^{29 to} R ³⁸ are bonded to each other to form a ring, and the hydrogen atom contained in the ring is , A halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms, The methylene group contained in the ring may be replaced with a carbonyl group or an oxygen atom.
t2 and t3 each independently represents an integer of 0 to 3.
When t2 is 2 or more, the plurality of R ²⁹ are the same or different, and the plurality of R ³⁰ are the same or different.
When t3 is 2 or more, the plurality of R ³⁶ are the same or different, and the plurality of R ³⁷ are the same or different. ]

[In the formula (II-3),
R ²¹ and A ²¹ represent the same meaning as described above.
^R39 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms.
t4 represents an integer of 0 to 8.
When t4 is 2 or more, the plurality of ^R39s are the same or different. ]

Specific examples of the structural unit (II) are shown below.
In the above structural unit, a structural unit in which a methyl group corresponding to R ²¹ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (II).

The structural unit (II) is derived from a compound represented by the formula (II ′).
[All the symbols in formula (II ′) have the same meanings as described above. ]
The compound represented by the formula (II ′) can be produced, for example, by the method described in JP 2012-17264 A or according to this method.

  The content of the structural unit (II) is preferably 2 to 40% by mole, more preferably 3 to 35% by mole, and preferably 5 to 30% by mole with respect to all the structural units of the resin (A). It is.

<Structural unit having acid labile group>
A structural unit having an acid labile group (hereinafter sometimes referred to as “acid labile structural unit”) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “acid labile monomer (a1)”). .
Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

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

^Examples of the alkyl group represented by R ^a1 , R ^a2 and R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
Examples of the alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 include the same groups as the alicyclic hydrocarbon of the structural unit represented by the formula (II) of the ring X ²¹ . The alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 preferably has 3 to 16 carbon atoms.
Examples of the group obtained by combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms. In each formula, R ^a3 has the same meaning as described above, and * represents a bond to —O—.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and 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 ′} , R ^{a2 ′} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include groups in which one hydrogen atom has been removed from the hydrocarbon groups of R ^{a1 ′ to} R ^{a3 ′} .

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. * Represents a bond.

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

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If the resin composition (A) having a structural unit derived from an acid labile monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved. it can.

  As a structural unit derived from a (meth) acrylic monomer having a group represented by formula (1), preferably a structural unit represented by formula (a1-1) or a structure represented by formula (a1-2) Units are listed. These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are represented by the structural unit (a1-1) and the structural unit (a1-2), respectively. The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

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

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

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

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

Examples of the acid labile monomer (a1) include a monomer represented by the formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (hereinafter referred to as “monomer (a1-5)”). May be used).
In formula (a1-5),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or a * — [CH ₂ ] _k1 —CO—L ^a4 — group. Here, k1 represents an integer of 1 to 4. * Represents a bond with L ^a1 .
L ^a1 , L ^a2 , L ^a3 and L ^a4 each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ^a1 is preferably an oxygen atom.
One of L ^a2 and L ^a3 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

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

  When the resin (A) has a structural unit derived from the monomer (a1-5), the content is preferably from 1 to 50 mol%, preferably from 3 to 45 mol, based on all structural units of the resin (A). % Is more preferable, and 5 to 40 mol% is more preferable.

<Structural unit without acid labile group>
The structural unit having no acid labile group (hereinafter sometimes referred to as “acid stable structural unit”) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “acid stable monomer”).
As an acid stable monomer, Preferably, the monomer which has a hydroxyl group or a lactone ring is mentioned. If a resin having a structural unit derived from an acid-stable monomer having a hydroxy group or an acid-stable monomer containing a lactone ring is used, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group>
When the resist composition is used for KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV (ultra-ultraviolet light), an acid stable monomer having a hydroxy group (hereinafter referred to as “acid stable monomer (a2)”) Preferably, an acid stable monomer having a phenolic hydroxy group is used. When ArF excimer laser exposure (193 nm) or the like is used, an acid stable monomer having a hydroxyadamantyl group represented by the formula (a2-1) is preferably used as the acid stable monomer (a2) having a hydroxy group. An acid stable monomer (a2) may be used individually by 1 type, and may use 2 or more types together.

Examples of the acid-stable monomer having a hydroxyadamantyl group include an acid-stable 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.

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

  When the resin (A) includes a structural unit derived from the acid-stable monomer (a2), the content thereof is usually 3 to 45 mol% with respect to all the structural units of the resin (A), preferably 1 to 1%. It is 40 mol%, More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Acid-stable monomer having a lactone ring>
The lactone ring possessed by the acid-stable monomer containing a lactone ring (hereinafter sometimes referred to as “acid-stable monomer (a3)”) is, for example, a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring. A monocyclic ring or a condensed ring of a monocyclic lactone ring and another 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) does not include the compound (I ′).

  The acid stable monomer (a3) is preferably an acid stable monomer 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), formula (a3-2) and formula (a3-3),
L ^a4 , L ^a5 and 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 , R ^a19 and R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an alkyl group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an alkyl group having 1 to 4 carbon atoms.
q1 and r1 each independently represents an integer of 0 to 3. When p1 is 2 or more, a plurality of R ^a21 are the same or different, when q1 is 2 or more, a plurality of R ^a22 are the same or different, and when r1 is 2 or more, a plurality of R ^a23 are the same or different Different.

^Examples of the alkyl group for R ^a21 , R ^a22 and 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), formula (a3-2) and formula (a3-3), L ^a4 , L ^a5 and L ^a6 are each independently —O— or ^* —O— (CH ₂ ) _k3 —. CO-O- is preferable, and -O- is more preferable. k3 is preferably an integer of 1 to 4, more preferably 1.
R ^a18 , R ^a19 , R ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably 0 to 2, more preferably 0 or 1.

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

  When the resin (A) contains a structural unit derived from the acid-stable monomer (a3), the content is usually 5 to 70 mol%, preferably 10 to 10%, based on all structural units of the resin (A). It is 65 mol%, More preferably, it is 10-60 mol%.

When the resin (A) is a resin composed only of the structural unit (I), the structural unit (II), and the acid labile structural unit, these contents are respectively based on the total structural units of the resin (A). ,
Structural unit (I); 1 to 80 mol%
Structural unit (II); 2 to 40 mol%
Acid labile structural unit; 18-97 mol%
Is preferred,
Structural unit (I); 5-65 mol%
Structural unit (II); 5 to 30 mol%
Acid-labile structural unit; 30 to 90 mol%
Is more preferable.

When the resin (A) is a resin composed of the structural unit (I), the structural unit (II), the acid labile structural unit, and the acid stable structural unit, these contents are respectively the total structure of the resin (A). For units
Structural unit (I); 1 to 80 mol%
Structural unit (II); 2 to 40 mol%
Acid labile structural unit; 15-94 mol%
Acid stable structural unit; 3-82 mol%
Is preferred,
Structural unit (I); 3-70 mol%
Structural unit (II); 3-35 mol%
Acid-labile structural unit; 20 to 87 mol%
Acid stable structural unit; 7 to 74 mol%
Is more preferred,
Structural unit (I); 5-55 mol%
Structural unit (II); 5 to 30 mol%
Acid labile structural unit; 25-75 mol%
Acid stable structural unit; 15-65 mol%
Is more preferred,
Structural unit (I); 5-35 mol%
Structural unit (II); 5-35 mol%
Acid labile structural unit; 40-65 mol%
Acid stable structural unit; 20 to 55 mol%
Is particularly preferred.

The resin (A) is preferably a resin comprising a structural unit (I), a structural unit (II), an acid labile structural unit, and an acid stable structural unit, that is, a compound (I ′) and a structural unit (II). It is a copolymer of a leading monomer, an acid labile monomer (a1) and an acid stable monomer.
The acid labile structural unit is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit (a1- 1).
The acid stable structural unit is preferably at least one of a structural unit derived from the acid stable monomer (a2) and a structural unit derived from the acid stable monomer (a3). The acid stable monomer (a2) is preferably a monomer represented by the formula (a2-1). The acid stable monomer (a3) is preferably at least one of an acid stable monomer represented by the formula (a3-1) and an acid stable monomer represented by the formula (a3-2).

  The resin (A) may contain a structural unit derived from a monomer having an adamantyl group (particularly the structural unit (a1-1)) in an amount of 15 mol% or more based on the content of the acid labile structural unit. preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

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

<Resist composition>
The resist composition of the present invention comprises:
Resin (A) and an acid generator (hereinafter may be referred to as “acid generator (B)”) are contained.
It is preferable that the resist composition of the present invention further contains a solvent (E).
Moreover, it is preferable that the resist composition of this invention contains the basic compound (C) further.

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

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A).
The resin other than the resin (A) is not particularly limited as long as the resin does not contain the structural unit (I). For example, in addition to the above-mentioned acid-labile structural unit and acid-stable structural unit, the resin is used in this field. Examples of the resin include structural units derived from known monomers.
When the resist composition of this invention contains resin other than resin (A), these content rates are 0.1-50 mass% normally with respect to the total amount of resin, Preferably 0.5-30 It is mass%, More preferably, it is 1-20 mass%.

<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). -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 (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712. A compound capable of generating an acid by radiation described in No. etc. can be used. Moreover, you may use the compound manufactured by the well-known method.

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

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents a hydrogen atom, a fluorine atom, or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z ⁺ represents an organic cation. ]

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 perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. And perfluorohexyl group.
Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group represented by L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1, Branched alkanediyl groups such as 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 saturated hydrocarbon group represented by L ^{b1 in} which the methylene group is replaced with an oxygen atom or a carbonyl group include formula (b1-1) to formula (b1-7). In addition, Formula (b1-1)-Formula (b1-7) have described the right and left according to Formula (B1), and among two bonds represented by *, C (Q ¹ ) Combined with (Q ² )-and combined with -Y on the right side. The same applies to specific examples of the following formulas (b1-1) to (b1-7).

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

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

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

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

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

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

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

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

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

Specific examples when the hydrogen atom contained in the aliphatic saturated hydrocarbon group of L ^b1 is substituted with a fluorine atom or a hydroxy group include the following.

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

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 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 the above substituents may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.

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

Examples of Y include the following.

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

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

Examples of the organic cation (Z1 ⁺ ) contained in the salt (B1) include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. An organic sulfonium cation or an organic iodonium cation, more preferably an arylsulfonium cation, and still more preferably a cation represented by any one of formulas (b2-1) to (b2-4).

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represents a hydrocarbon group having 1 to 36 carbon atoms. This hydrocarbon group preferably represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, and an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may together form a ring containing a sulfur atom.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5, when m2 is 2 or more, the plurality of R ^b7 are the same or different, and when n2 is 2 or more, the plurality of R ^b8 are the same or different. .
R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or R ^b9 and R ^{b10 taken} together Forms a ring containing a sulfur atom to which.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. —CH ₂ — contained in the ring may be replaced by —O—, —S— or —CO—.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, and the aliphatic hydrocarbon group includes The contained hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is an alkoxy group having 1 to 12 carbon atoms or 1 carbon atom. It may be substituted with ˜12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be combined to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with —CH—CO— to which they are bonded.

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, multiple R ^b13 are the same or different, when p2 is 2 or more, multiple R ^b14 are the same or different, and when q2 is 2 or more, multiple R ^b15 are the same or different , When r2 is 2 or more, a plurality of R ^b16 are the same or different, when s2 is 2 or more, a plurality of R ^b17 are the same or different, and when t2 is 2 or more, a plurality of R ^b18 are the same or different Different.

Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. And cycloalkyl groups such as groups. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. * Represents a bond.
Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a 2-alkyladamantan-2-yl group, and a methylnorbornyl group. Group, isobornyl group and the like.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Group, phenanthryl group, 2,6-diethylphenyl group, and aryl groups such as 2-methyl-6-ethylphenyl.
When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms Groups are preferred.

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.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the halogen atom include 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 aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms, and in particular, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert group. -A butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group and the like are preferable.
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-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl 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.
^Examples of the alkyl group in which a hydrogen atom of R ^b12 is substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.

The ring containing a sulfur atom which may be formed by combining R ^b4 and R ^b5 is any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. 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.

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.

  Specific examples of the organic cation represented by the formulas (b2-1) to (b2-4) include those described in JP2010-204646A.

Among them, the organic cation Z ⁺ is preferably a cation (b2-1), more preferably an organic cation represented by the formula (b2-1-1) (hereinafter referred to as “cation (b2-1-1)”). More preferably, triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (in formula (b2-1-1)) , V2 = w2 = 0, x2 = 1, R ^b21 is a methyl group) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, R ^b19 , R ^b20 and R ^b21 are all methyl groups.

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom) hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or 3 carbon atoms. Represents -18 alicyclic hydrocarbon groups. It is also possible that two selected from R ^b19 to R ^b21 together form a ring containing a sulfur atom.
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 aliphatic hydrocarbon group having 1 to 12 carbon atoms or a carbon number of 1 to 12 Of the alkoxy group.

  Specific examples of the cation (b2-1-1) include cations described in JP 2010-204646 A.

  The salt (B1) is a combination of the above sulfonic acid anion and the above organic cation. These can be arbitrarily combined, and preferably a combination of any one of anion (b1-1-1) to anion (b1-1-9) and a cation (b2-1-1), and an anion (b1-1) -3) to (b1-1-5) and a combination of a cation (b2-3).

  The salt (B1) is preferably a salt represented by the formula (B1-1) to the formula (B1-20). Among them, those containing an arylsulfonium cation are preferable, and the formula (B1-1), formula (B1-2), formula (B1-3, formula (B1-6), formula (B1-7), formula (B1-11) A salt represented by formula (B1-12), formula (B1-13), formula (B1-14), formula (B1-18), formula (B1-19) or formula (B1-20). preferable.

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).
The acid generator (B) may contain 1 type independently, and may contain 2 or more types.

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

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

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

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

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

[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, and 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 represent an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different, and when r3 is 2 or more, the plurality of R ^c19 are the same. Or when different and when s3 is 2 or more, the plurality of R ^c20 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

In formula (C1) to formula (C8) and formula (C1-1), the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group, alkanediyl group are the same as those described above. Is mentioned.
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

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

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

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

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

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

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

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

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various types of laser light such as those that convert 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 reaction of the resin (A). The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

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

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

When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Ether solvents; amide solvents such as N, N-dimethylacetamide and aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
It is preferable to wash the developed resist pattern with a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

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

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

Synthesis Example 1 (Synthesis of monomer (M-K))
33.48 parts of the compound represented by the formula (K-1), 23.93 parts of dicyclohexylcarbodiimide and 40 parts of methylene chloride were charged into a reactor and mixed. After cooling the obtained mixture to about 0 ° C., 18.83 parts of the compound represented by the formula (K-2) was added, and the mixture was stirred for about 1 hour while maintaining about 0 ° C. The temperature was raised to 23 ° C. and the mixture was further stirred for 30 minutes. Insoluble matters were removed by filtration, and the obtained filtrate was concentrated to obtain 44.28 parts of a compound represented by the formula (K-3).

A reactor was charged with 19.42 parts of the compound represented by the formula (K-3) obtained as described above, 18.22 parts of the compound represented by the formula (K-4) and 200 parts of acetonitrile. Mixed. The resulting mixture was stirred at 50 ° C. for 3 hours. The obtained mixture was concentrated, 300 parts of chloroform and 150 parts of ion-exchanged water were added, and then the organic layer was recovered by a liquid separation operation. The recovered organic layer was washed with 150 parts of ion exchange water, and then the organic layer was concentrated. The concentrate is subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd. developing solvent: ethyl acetate) to obtain 12.89 parts of a compound represented by the formula (M-K). It was.
MS (mass spectrometry): 308.1 (molecular ion peak)

Synthesis Example 2 [Synthesis of Compound Represented by Formula (ML)]
16.89 parts of sodium hydride and 152 parts of toluene were charged, and a solution obtained by dissolving 55.56 parts of (−)-10,2-camphorsultam in 345 parts of toluene was added dropwise over 1 hour. Subsequently, a solution obtained by diluting 34.97 parts of chloroacetyl chloride with 108 parts of toluene was added dropwise over 1 hour and stirred for 6 hours. To the resulting reaction solution, 305 parts of ion exchange water and 457 parts of ethyl acetate were added to extract the organic layer. The recovered organic layer was washed with 152 parts of 1M aqueous sodium hydrogen carbonate solution, then washed with 251 parts of brine and dried over magnesium sulfate. After drying, the organic solvent was removed, and silica gel column purification using n-heptane and ethyl acetate as developing solvents was performed to obtain 58.67 parts of the compound represented by the formula (L-1).

  25.95 parts of methacrylic acid and 259 parts of N, N-dimethylformamide were added, and 41.65 parts of potassium carbonate and 12.51 parts of potassium iodide were further added, and the temperature was raised to 50 ° C. A solution prepared by dissolving 58.63 parts of the compound represented by the formula (L-1) in 120 parts of N, N-dimethylformamide was added dropwise to the obtained reaction mass over 1 hour, followed by stirring at 50 ° C. for 6 hours. To the obtained reaction mass, 520 parts of ion-exchanged water and 390 parts of ethyl acetate were added to extract the organic layer. The collected organic layer was washed with 520 parts of ion exchange water and dried over magnesium sulfate. After drying, the organic solvent was removed, and silica gel column purification using n-heptane and ethyl acetate as developing solvents was performed to obtain 67.24 parts of a compound represented by the formula (ML).

MS (mass spectrometry): 341.1 (molecular ion peak)

Synthesis Example 3: Synthesis of salt represented by formula (B1-5)
50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of the salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

Resin synthesis Monomers used in resin synthesis are shown below.
Hereinafter, these monomers are referred to as “monomer (MA)” to “monomer (MM)” depending on the reference numerals.

Example 1 [Synthesis of Resin A1]
As a monomer, a monomer (MG), a monomer (ME), a monomer (MB), a monomer (M-H), a monomer (M-K), and a monomer (ML), and their molar ratio (Monomer (MG): monomer (ME): monomer (MB): monomer (MH): monomer (MK): monomer (ML)) is 32: 7: 8: It mixed so that it might be set to 33:10:10, and 1.5 mass times dioxane of the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are 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 thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 0 × 10 ³ resin A1 (copolymer) was obtained in a yield of 72%. This resin A1 has the following structural units.

Example 2 [Synthesis of Resin A2]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-J), a monomer (MD), a monomer (M-K) and a monomer (ML) are used, and the molar ratio thereof. (Monomer (MF): monomer (MI): monomer (MJ): monomer (MD): monomer (MK): monomer (ML)) 45: 14: 2. The mixture was mixed at 5: 22.5: 8: 8, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 73 ° 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 thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 8 × 10 ³ resin A2 (copolymer) was obtained with a yield of 58%. This resin A2 has the following structural units.

Example 3 [Synthesis of Resin A3]
As the monomer, monomer (MF), monomer (M-I), monomer (M-J), monomer (MD), monomer (M-H), monomer (M-K) and monomer (ML) ) And its molar ratio (monomer (MF): monomer (M-I): monomer (M-J): monomer (MD): monomer (M-H): monomer (M-K): Monomers (ML)) were mixed so as to be 45: 14: 2.5: 17.5: 5: 8: 8, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are 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 thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 9 × 10 ³ resin A3 (copolymer) was obtained with a yield of 55%. This resin A3 has the following structural units.

Example 4 [Synthesis of Resin A4]
As a monomer, a monomer (M−F), a monomer (M−M), a monomer (M−J), a monomer (M−D), a monomer (M−K), and a monomer (M−L) are used, and a molar ratio thereof. [Monomer (MF): Monomer (MM): Monomer (MJ): Monomer (MD): Monomer (MK): Monomer (ML)] is 45: 14: 2. 5: 22.5: 8: 8 were mixed, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A4 (copolymer) having a molecular weight of 8.0 × 10 ³ was obtained in a yield of 62%. This resin A4 has the following structural units.

Example 5 [Synthesis of Resin A5]
As a monomer, a monomer (MG), a monomer (MM), a monomer (MB), a monomer (M-H), a monomer (M-K), and a monomer (ML), the molar ratio [Monomer (MG): Monomer (MM): Monomer (MB): Monomer (M-H): Monomer (M-K): Monomer (ML)] is 32: 7: 8: The mixture was mixed at 43: 5: 5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A5 (copolymer) having a molecular weight of 8.1 × 10 ³ was obtained in a yield of 80%. This resin A5 has the following structural units.

[Synthesis of Resin H1]
Monomer (MA) and monomer (MC) are used as monomers and mixed so that the molar ratio (monomer (MA): monomer (MC)) is 40:60. An amount of 1.5 mass times dioxane was added to prepare a solution. To the solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.4 mol% and 4.2 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 resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 0 × 10 ³ resin H1 (copolymer) was obtained in a yield of 92%. This resin H1 has the following structural units.

Examples 6 to 11 and Comparative Example 1
<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1 to A5, H1: Resin A1 to Resin A5, Resin H1
<Acid generator>
B1-3: synthesized according to the example of JP 2010-152341 A
B1-5:
B2: Triphenylsulfonium triflate (manufactured by TPS-105 Midori Chemical Co., Ltd.)

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

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

<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Co., Ltd.] is applied onto a 12-inch silicon wafer, and baked at 205 ° C. for 60 seconds to obtain an organic material having a thickness of 780 mm. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 100 nm. After coating, the composition layer was formed on the silicon wafer by pre-baking on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 1.
ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annual σ _out = 0.85 σ _in = 0.65 XY-pol on a silicon wafer on which the composition layer is formed . Illumination], using a mask for forming a trench pattern (pitch 120 nm / trench 40 nm), the exposure was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1. Next, the composition layer on the silicon wafer was subjected to paddle development at 23 ° C. for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developer to obtain a negative resist pattern.

  In the obtained resist pattern, the exposure amount at which the width of the trench pattern was 40 nm was defined as effective sensitivity.

<Line edge roughness evaluation (LER)>
About the resist pattern obtained in the effective sensitivity, the uneven | corrugated fluctuation width of the side wall of a resist pattern was measured using the scanning electron microscope. This swing is
○ that is 5 nm or less,
The thing exceeding 5 nm was set as x.
The results are shown in Table 2. A numerical value in parentheses indicates a swing width (nm).

Examples 12 to 17 and Comparative Example 2
Except for changing the developer to 2-heptanone (manufactured by Kyowa Hakko Co., Ltd.), the same operation as described above was performed to produce a negative resist pattern, and the same evaluation as in the examples was performed. The results are shown in Table 3.

  From the above results, it can be seen that the resist composition of the present invention can produce a negative resist pattern having excellent line edge roughness.

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

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

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

<Line edge roughness evaluation (LER)>
The wall surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and the fluctuation width (nm) of the unevenness on the side wall of the resist pattern was obtained. The results are shown in Table 5.

  From the above results, it can be seen that according to the resist composition of the present invention, an excellent line edge roughness (LER) negative resist pattern can be produced.

  According to the resist composition of the present invention, a resist pattern having excellent line edge roughness (LER) can be produced.

Claims (4)

For resists comprising a structural unit represented by formula (I), a structural unit represented by formula (II), and a structural unit having a group represented by formula (1) or a group represented by formula (2) resin.
[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O— or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]
[In the formula (II),
R ²¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ²¹ represents a divalent linking group.
Ring X ²¹ represents a heterocyclic ring having 2 to 36 carbon atoms.
R ²² is a halogen atom, a hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxyalkyl group having 1 to 24 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a carbon number 2 to 4 acyloxy groups are represented.
m represents an integer of 0 to 10.
When m is 2 or more, the plurality of R ²² are the same or different. ]
[In Formula (1),
Which R ^a1, R ^a2 and a R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or a group obtained by combining these C3-20, R ^a1 and R ^a2 combine with each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]
[In Formula (2),
R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^{a2 ′} and R ^{a2 ′} R ^{a3 ′} is 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 — It may be replaced by S-. ] Resist composition comprising claim 1 Symbol placing the resin and acid generator. Furthermore, the resist composition of Claim 2 containing a solvent. (1) The process of apply | coating the resist composition of Claim 2 or 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.