JP2012048155A - Resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that resolution of a resist pattern obtained in a conventional resist composition is not always satisfactory.SOLUTION: An resist composition of this invention comprises: a resin which is insoluble or sparingly soluble in an aqueous alkali solution, and can dissolve in an aqueous alkali solution by an action of an acid; an acid generator; a photobase generator; a compound represented by formula (I); and a solvent. [In formula (I), Rand Rare each independently a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, or a heterocyclic group, or may be bonded to each other to form a ring.]

Description

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

  Conventionally, various resist compositions have been proposed, for example, a resin obtained by polymerizing 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate and α-methacryloyloxy-γ-butyrolactone. Chemically amplified resist composition comprising an acid generator composed of 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate, a quencher composed of 2,6-diisopropylaniline, and a solvent (See Patent Document 1 (Example 1)).

JP 2006-257078 A

  In the conventional resist composition, the resolution of the resist pattern obtained is not always satisfactory.

The present invention includes the following inventions.
[1] A resin that is insoluble or hardly soluble in an aqueous alkaline solution and becomes soluble in an aqueous alkaline solution by the action of an acid, an acid generator, a photobase generator, a compound represented by formula (I), and a solvent A resist composition comprising:

[In Formula (I), R ¹ and R ² each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms or a heterocyclic group, or are bonded to each other to form a ring. ]

[2] The resist composition according to [1], wherein the photobase generator is a compound represented by the formula (II).

[In Formula (II), R ³ represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ⁴ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group includes an alkyl group having 1 to 6 carbon atoms and an alicyclic carbon atom having 3 to 20 carbon atoms. It may be substituted with a hydrogen group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a nitro group, a hydroxyl group or a cyano group.
R ⁵ represents an alkyl group having 1 to 6 carbon atoms, a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms having a fluorine atom, and the saturated hydrocarbon —CH ₂ — contained in the group may be replaced by —O—, —CO— or —SO ₂ —. ]

[3] (1) A step of applying the resist composition according to [1] or [2] on a substrate,
(2) forming a composition layer on the substrate by removing the solvent from the resist composition coated on the substrate;
(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;
A method for producing a resist pattern including:

  According to the resist composition of the present invention, a resist pattern having excellent resolution can be produced.

  The resist composition of the present invention is represented by the formula (I), a resin that is insoluble or hardly soluble in an aqueous alkali solution and becomes soluble in an aqueous alkali solution by the action of an acid, an acid generator, and a photobase generator. A compound and a solvent. Hereinafter, each of a resin, an acid generator, a photobase generator, a compound represented by the formula (I) and a solvent will be described, and a resist composition containing them and a method for producing a resist pattern using the resist composition will be described. explain.

<Resin>
The resin used for the resist composition of the present invention (hereinafter referred to as “resin (A)”) is insoluble or hardly soluble in an aqueous alkali solution and is converted into a resin soluble in an aqueous alkaline solution by the action of an acid. Has characteristics. “Becomes alkali-soluble by the action of an acid” means insoluble or hardly soluble in an aqueous alkali solution before contact with an acid, but becomes soluble in an aqueous alkali solution after contact with an acid. In such a resin (A), a part or all of the hydrophilic group in the molecule is protected by a protecting group that can be removed by contact with an acid, and the resin (A) is in contact with an acid. Then, the protecting group is eliminated, and the resin (A) is converted into a resin soluble in an alkaline aqueous solution. The hydrophilic group protected by the protecting group is hereinafter referred to as “acid labile group”. Examples of the hydrophilic group include a hydroxy group or a carboxy group, and a carboxy group is more preferable.

  The resin (A) can be produced by polymerizing a monomer having an acid labile group (hereinafter referred to as “monomer (a1)”). In the polymerization, only one type of monomer (a1) may be used, or two or more types may be used in combination.

<Monomer having an acid labile group (monomer (a1))>
As already explained, the monomer (a1) has an acid labile group. The acid labile group in the case where the hydrophilic group is a carboxy group is, for example, that the hydrogen atom of the carboxy group is replaced with an organic residue, and the atom of the organic residue bonded to the oxy group is a tertiary carbon atom (provided that And a group which is a bridged cyclic hydrocarbon group (excluding bridgehead carbon atoms). Among such acid labile groups, preferred acid labile groups are, for example, those represented by the following formula (1) (hereinafter sometimes referred to as “acid labile groups (1)”).

[In the formula (1), R ^a1 , R ^a2 and R ^a3 (hereinafter sometimes referred to as “R ^{a1 to} R ^a3 ”) are each independently an aliphatic hydrocarbon having 1 to 8 carbon atoms. Represents a group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a1 and R ^a2 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. When the ring formed by combining R ^a1 and R ^a2 , the aliphatic hydrocarbon group or the alicyclic hydrocarbon group has a methylene group, the methylene group is an oxy group, a thio group (—S— ) Or a carbonyl group.
* Represents a bond. ]

Examples of the aliphatic hydrocarbon group represented by R ^{a1 to} R ^a3 include an alkyl group. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group represented by R ^{a1 to} R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and methylnorbornyl group, and groups shown below.

[In the formula, * represents a bond. ]

The alicyclic hydrocarbon group represented by R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

Examples of the ring formed by combining R ^a1 and R ^a2 include alicyclic hydrocarbon groups such as monocyclic and polycyclic. Specific examples of the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in formula (1) include those shown below. Among these, a ring having 3 to 12 carbon atoms is preferable.

[In the formula, * represents a bond with an oxygen atom. ]

Specific examples of the acid labile group (1) include, for example, a 1,1-dialkylalkoxycarbonyl group (in the formula (1), wherein R ^{a1 to} R ^a3 are alkyl groups, at least one of R ^{a1 to} R ^a3 One is preferably a tert-butoxycarbonyl group.), 2-alkyl-2-adamantyloxycarbonyl group (in formula (1), R ^a1 and R ^a2 are bonded to each other and together with the carbon atom to which they are bonded, an adamantyl ring) Wherein R ^a3 is an alkyl group) and 1- (1-adamantyl) -1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl). Group which is a group).

  The monomer (a1) is preferably a monomer having both an acid labile group (1) and a carbon-carbon double bond in the molecule, and more preferably a (meth) acrylic group having an acid labile group (1). Monomer. Here, the “(meth) acrylic monomer” means a monomer having an acryloyl group or a methacryloyl group.

  Among the (meth) acrylic monomers having an acid labile group (1), those having an acid labile group (1) having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. The resin (A) obtained by polymerizing the monomer (a1) having such a sterically bulky alicyclic hydrocarbon group was produced using a resist composition containing the resin (A). Sometimes, a resist pattern can be manufactured with better resolution.

  Among the (meth) acrylic monomers having an acid labile group (1) having an alicyclic hydrocarbon group, the monomer represented by the formula (a1-1) (hereinafter referred to as “monomer (a1-1)”). ) Or a monomer represented by formula (a1-2) (hereinafter referred to as “monomer (a1-2)”). When manufacturing resin (A), these may be used independently and may use 2 or more types together.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent an oxy group or a group represented by * —O— (CH ₂ ) _k1 —CO—O—. Here, k1 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
o1 represents an integer of 0 to 3.
In addition, in the formula (a1-1), the notation “— (CH ₃ ) _m1 ” in the adamantane ring means that the hydrogen atom of the methylene group and / or methine group in the adamantane ring is replaced with a methyl group, This means that the number of methyl groups bonded to is m1. ]

L ^a1 and L ^a2 are preferably a group represented by an oxy group or * —O— (CH ₂ ) _f1 —CO—O— (where f1 represents an integer of 1 to 4), more preferably It is an oxy group. f1 is more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the aliphatic hydrocarbon group represented by R ^a6 and R ^a7 include those exemplified above for R ^{a1 to} R ^a3 . The aliphatic hydrocarbon group for R ^a6 or R ^a7 is preferably a group having 6 or less carbon atoms.
Examples of the alicyclic hydrocarbon group represented by R ^a6 or R ^a7 include those exemplified above for R ^{a1 to} R ^a3 . The alicyclic hydrocarbon group represented by R ^a6 or 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.
o1 is preferably 1.

  As a monomer (a1-1) which has an adamantyl group, the following are mentioned, for example.

  Among these, as the monomer (a1-1), 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate and 2-isopropyl-2-adamantyl (meth) acrylate are preferable. 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate and 2-isopropyl-2-adamantyl methacrylate are more preferred. Here, “(meth) acrylate” means acrylate or methacrylate.

  As a monomer (a1-2) which has a cycloalkyl group, the following are mentioned, for example.

  Among these, as a monomer (a1-2), what has a cycloalkyl group is preferable, 1-ethylcyclohexyl (meth) acrylate is more preferable, and 1-ethylcyclohexyl methacrylate is further more preferable.

  The content of the structural unit derived from the monomer (a1) in the resin (A) is preferably 10 mol% or more (more preferably 15 mol% or more, more preferably 20 mol% or more), preferably in all units of the resin. Is 95 mol% or less (more preferably 90 mol% or less, still more preferably 85% or less).

  In particular, when the resin (A) is produced using the monomer (a1-1) and / or the monomer (a1-2), when the total structural unit of the resulting resin (A) is 100 mol%, these monomers The total content of the derived structural units is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, and still more preferably in the range of 20 to 85 mol%. In order to bring the total content of the structural unit derived from the monomer (a1-1) and / or the structural unit derived from the monomer (a1-2) into such a range, when producing the resin (A) In addition, the amount of the monomer (a1-1) and / or the monomer (a1-2) used may be adjusted with respect to the amount of all the monomers used.

  Moreover, when using the monomer (especially monomer (a1-1)) which has an adamantyl group for a monomer (a1), it has an adamantyl group with respect to the total amount (100 mol%) of this monomer (a1) usage-amount. The amount of the monomer used is preferably 15 mol% or more. If it does in this way, there exists a tendency for the dry etching tolerance of the resist pattern obtained from the resist composition containing resin (A) to become more favorable.

<Acid stable monomer>
The resin (A) is preferably a copolymer obtained using a monomer having no acid labile group (hereinafter sometimes referred to as “acid-stable monomer”) in addition to the monomer (a1).
When the resin (A) is produced by using an acid-stable monomer in combination, the amount of acid-stable monomer may be determined based on the amount of monomer (a1) used. The ratio of the amount of monomer (a1) used and the amount of acid-stable monomer used is represented by [monomer (a1)] / [acid-stable monomer], preferably 10 to 80 mol% / 90 to 20 mol%, More preferably, it is 20-60 mol% / 80-40 mol%.

  As the acid stable monomer, those having a hydroxy group or a lactone ring in the molecule are suitable. A structure derived from an acid-stable monomer having a hydroxy group (hereinafter referred to as “acid-stable monomer (a2)”) and / or an acid-stable monomer having a lactone ring (hereinafter referred to as “acid-stable monomer (a3)”). When the resin (A) having a unit is coated on a substrate with a resist composition containing the resin (A), the adhesion between the coating film formed on the substrate or the composition layer obtained from the coating film and the substrate More improved. Therefore, this resist composition can produce a resist pattern with good resolution.

  First, the acid stable monomer (a2) and the acid stable monomer (a3) suitable as the acid stable monomer will be described with specific examples.

<Acid stable monomer (a2)>
When the acid-stable monomer (a2) is used, a suitable acid-stable monomer (a2) can be mentioned depending on the type of exposure source when obtaining a resist pattern from the resist composition containing the resin (A). . That is, when the resist composition is used for KrF excimer laser exposure (wavelength: 248 nm), high energy beam exposure such as electron beam or EUV light, the acid stable monomer having a phenolic hydroxyl group as the acid stable monomer (a2) [For example, hydroxystyrenes and the like] are preferably used. When short-wave ArF excimer laser exposure (wavelength: 193 nm) is used, it is preferable to use an acid-stable monomer having a hydroxyadamantyl group represented by the formula (a2-1) as the acid-stable monomer (a2).

[In the formula (a2-1),
L ^a3 represents an oxy group or * —O— (CH ₂ ) _k2 —CO—O—, and k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a8 represents a hydrogen atom or a methyl group.
R ^a9 and R ^a10 each independently represents a hydrogen atom, a methyl group or a hydroxy group.
p1 represents the integer of 0-10. ]

In formula (a2-1), L ^a3 is preferably an oxy group, * —O— (CH ₂ ) _e1 —CO—O— (where e1 is an integer from 1 to 4), and more Preferably it is an oxy group.
R ^a8 is preferably a methyl group.
R ^a9 is preferably a hydrogen atom.
R ^a10 is preferably a hydrogen atom or a hydroxy group.
p1 is preferably an integer of 0 to 3, more preferably 0 or 1.

  Examples of the acid stable monomer (a2-1) include the following.

  Among these, as the acid stable monomer (a2-1), 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate and (meth) acrylic acid 1- (3 , 5-dihydroxy-1-adamantyloxycarbonyl) methyl, 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylate are more preferred, and 3-hydroxy-1- More preferred are adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate.

  As described above, the acid-stable monomer (a2) used for the resin (A) can be selected according to the exposure source used for producing the resist pattern, but the acid-stable monomer (a2) can be selected from the exposure source. Depending on the type of the monomer, only one suitable monomer may be used, two or more suitable monomers may be used according to the type of exposure source, or a suitable monomer according to the type of exposure source, You may use 2 or more types which combined the acid stable monomer (a2) other than that.

  The content of the structural unit derived from the acid-stable monomer (a2) in the resin (A) is preferably 3 mol% or more (more preferably 5 mol% or more, more preferably 7 mol% or more) in all units of the resin. , Preferably 40 mol% or less (more preferably 35 mol% or less, still more preferably 30% or less).

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

  The acid stable monomer (a3) is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). In manufacture of resin (A), only 1 type may be used among these and 2 or more types may be used together. In the following description, the acid stable monomer (a3) represented by the formula (a3-1) is referred to as “acid stable monomer (a3-1)”, and the acid stable monomer (a3) represented by the formula (a3-2) is represented as “ The acid stable monomer (a3-2) and the acid stable monomer (a3) represented by the formula (a3-3) are referred to as “acid stable monomer (a3-3)”.

[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 ^a11 , R ^a12 and R ^a13 each independently represent a hydrogen atom or a methyl group.
R ^a14 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 5.
R ^a15 and R ^a16 each independently represent a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 and s1 each independently represents an integer of 0 to 3.
When q1, r1 or s1 is 2 or more, a plurality of R ^a14 , R ^a15 or R ^a16 are each independent. ]

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are preferably each independently —O— or * —O— (CH ₂ ) _d1 —CO—O— ( Here, d1 is an integer of 1 to 4, and more preferably —O—.
R ^{a11 to} R ^a14 are preferably a methyl group.
R ^a15 and R ^a16 are each independently preferably a carboxy group, a cyano group or a methyl group.
q1, r1 and s1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

  Examples of the acid stable monomer (a3-1) having a γ-butyrolactone ring include the following.

  Examples of the acid stable monomer (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring include the following.

  Examples of the acid stable monomer (a3-3) having a condensed ring of a γ-butyrolactone ring and a cyclohexane ring include the following.

Among acid-stable monomers (a3) having a lactone ring, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl, (meth) acrylic Acid tetrahydro-2-oxo-3-furyl, 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl (meth) acrylate And methacrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl, tetrahydro-2-oxo-3-furyl methacrylate, 2- (methacrylic acid 2- ( 5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl is more preferred.

  The content of the structural unit derived from the acid-stable monomer (a3) in the resin (A) is preferably 5 mol% or more (more preferably 10 mol% or more, more preferably 15 mol% or more) in the total unit of the resin. , Preferably 50 mol% or less (more preferably 40 mol% or less, and still more preferably 35% or less).

  The resin (A) is preferably a copolymer obtained by polymerizing the monomer (a1), the acid stable monomer (a2) and / or the acid stable monomer (a3). In this preferable copolymer, it is preferable to use at least one of the above-mentioned monomer (a1-1) and monomer (a1-2) as monomer (a1), and it is more preferable to use monomer (a1-1). . The acid stable monomer (a2) is preferably an acid stable monomer (a2-1), and the acid stable monomer (a3) is at least one of an acid stable monomer (a3-1) and an acid stable monomer (a3-2). Is preferred.

  Resin (A) uses monomer (a1) and, if necessary, acid-stable monomer (a2) and acid-stable monomer (a3), which are suitable for all structural units of resin (A) as described above. After adjusting the amount of use so as to achieve a sufficient content, it can be produced by a known polymerization method (for example, radical polymerization method).

  The weight average molecular weight of the resin (A) is preferably 2,500 or more, more preferably 3,000 or more. The upper limit of the weight average molecular weight is preferably 50,000 or less, and more preferably 30,000 or less. In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.

<Acid generator>
The resist composition contains an acid generator (hereinafter sometimes referred to as “acid generator (B)”). As the acid generator, a nonionic acid generator, an ionic acid generator, or a combination thereof can be used. Examples of nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, DNQ). 4-sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). 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, and JP-A-63-163452. JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent 3914407, European Patent 126, Compounds that generate an acid by radiation described in No. 712 and the like can be used as the acid generator (B).

As the acid generator (B), a fluorine-containing acid generator having a fluorine atom in the molecule is preferable. The acid generator (B) represented by the following formula (B1) (hereinafter referred to as “acid generator (B1)”) Is particularly preferred. This resist composition containing the acid generator (B1) and the compound (I) can not only produce a resist pattern with good line edge roughness (LER), but also produce a resist pattern with good focus margin (DOF). There is an advantage that you can. In the following description, among the acid generators (B1), Z ⁺ having a positive charge is referred to as “organic cation”, and a negative charge obtained by removing the organic cation is referred to as “sulfonate anion”. There is.

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and when the divalent saturated hydrocarbon group has a methylene group, the methylene group is replaced with an oxy group or a carbonyl group. It may be.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; When the aromatic hydrocarbon group and the alicyclic hydrocarbon group contain a methylene group, the methylene group may be replaced with a group selected from the group consisting of an oxy group, a sulfonyl group and a carbonyl group.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group of Q ¹ and Q ² is, for example, a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro-sec-butyl group, a perfluoro-tert-butyl group, a perfluoropentyl group, A perfluorohexyl group etc. are mentioned. 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 alkylene group, a branched alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon group, and two or more of these groups. May be combined.
Specific examples of the divalent saturated hydrocarbon group include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1, 5-diyl group, 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 A linear alkylene group such as a diyl group, a heptadecane-1,17-diyl group, a methylidene group, an ethylidene group, a propylidene group, or a 2-propylidene group; an alkyl group (particularly, A branched alkylene group having a side chain of a prime number 1-4 alkyl group, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, -Methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4 A branched alkylene group such as a butylene group; a cycloalkylene group such as a 1,3-cyclobutylene group, a 1,3-cyclopentylene group, a 1,4-cyclohexylene group, and a 1,5-cyclooctylene group; Monocyclic alicyclic hydrocarbon group; polycyclic alicyclic carbonization such as 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group, etc. Hydrogen group; etc. It is.

Examples of those in which the methylene group contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by an oxy group or a carbonyl group include the following formulas (b1-1), (b1-2), and (b1 -3), formula (b1-4), formula (b1-5) and formula (b1-6) [hereinafter expressed as “formula (b1-1) to formula (b1-6)”. ] The group shown by either of these is mentioned. L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably a group represented by formula (b1-1) or a formula (b1-2). It is the group shown. Incidentally, the formula (b1-1) ~ formula (b1-6) has its left and right are described in accordance with the formula (B1), the left bond ^{is, C (Q 1) (Q} 2) coupled with and The right hand is connected to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6). In addition, * represents a bond, one is bonded to Y, and the other is bonded to a carbon atom of CQ ¹ Q ² .

[In the formulas (b1-1) to (b1-6),
L ^b2 represents a single bond or a saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a saturated hydrocarbon group having 1 to 12 carbon atoms. L ^b4 represents a saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent a saturated hydrocarbon group having 1 to 11 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12. ]

Among these, as L ^b1 , a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or a methylene group. Is more preferable.

  Here, the specific example of the bivalent group represented by Formula (b1-1)-Formula (b1-6) is given. 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.

As the aliphatic hydrocarbon group for Y, an alkyl group is preferable, and an alkyl group having 1 to 6 carbon atoms is more preferable. The alkyl group may be linear or branched.
Moreover, as an alicyclic hydrocarbon group of Y, a cycloalkyl group is preferable and a C3-C12 cycloalkyl group is more preferable. The cycloalkyl group here may be monocyclic or polycyclic. Further, not only a cycloalkyl group having a carbon atom as a ring atom but also a group formed by bonding an alkyl group to a carbon atom of a ring atom is a cycloalkyl group.

When the aliphatic hydrocarbon group or alicyclic hydrocarbon group of Y contains a methylene group, the methylene group is a group selected from the group consisting of an oxy group, a sulfonyl group (—SO ₂ —), and a carbonyl group (divalent). May be replaced. Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group is replaced with an oxy group, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups contained in the alicyclic hydrocarbon group are A group substituted with an oxy group), a cyclic ketone group (a group in which one or two methylene groups contained in an alicyclic hydrocarbon group are replaced with a carbonyl group), a sultone ring group (included in an alicyclic hydrocarbon group) Two adjacent methylene groups in the methylene group are groups in which the oxy group and the sulfonyl group are substituted, respectively, and the lactone ring group (the two adjacent methylene groups in the methylene group contained in the alicyclic hydrocarbon group are: And groups in which an oxy group and a carbonyl group are substituted, respectively.

In particular, as the alicyclic hydrocarbon group of Y, the formula (Y1), the formula (Y2), the formula (Y3), the formula (Y4), the formula (Y5), the formula (Y6), the formula (Y7), the formula ( Y8), formula (Y9), formula (Y10), formula (Y11), formula (Y12), formula (Y13), formula (Y14), formula (Y15), formula (Y16), formula (Y17), formula (Y Y18), Formula (Y19), Formula (Y20), Formula (Y21), Formula (Y22), Formula (Y23), Formula (Y24), Formula (Y25), and Formula (Y26) [hereinafter, "Formula (Y1)" To the expression (Y26). ] The group represented by either of these is mentioned. Here, the groups represented by the formula (Y12) to the formula (Y26) are each selected from the group consisting of 1 to 3 methylene groups contained in the alicyclic hydrocarbon group each consisting of an oxy group, a sulfonyl group, and a carbonyl group. Corresponds to a group replaced by a selected divalent group. In the groups represented by these formulas (Y1) to (Y26), * represents a bond bonded to L ^b1 .

  Among these examples, Y is preferably a group represented by any one of formulas (Y1) to (Y19), and is represented by formula (Y11), formula (Y14), formula (Y15), or formula (Y19). The group represented is more preferable, and the group represented by the formula (Y11) or the formula (Y14) is more preferable.

As described above, Y may have a substituent. Here, the “aliphatic hydrocarbon group having a substituent” means a group in which a hydrogen atom in the aliphatic hydrocarbon group is substituted with a substituent. On the other hand, “an alicyclic hydrocarbon group having a substituent” means a group in which a hydrogen atom in the alicyclic hydrocarbon group is substituted with a substituent. Here, examples of the substituent include, for example, a halogen atom (excluding a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and 6 to 18 carbon atoms. An aromatic hydrocarbon group, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 represents an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 being 0 to 4 Represents an integer). The aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group and aralkyl group as the substituent may have, for example, an alkyl group, a halogen atom or a hydroxy group. Moreover, as a substituent which an aliphatic hydrocarbon group has, a C3-C16 alicyclic hydrocarbon group may be sufficient.

  Hereinafter, Y having a substituent is exemplified. Examples of Y having an aliphatic hydrocarbon group as a substituent include the following.

  Examples of Y having a hydroxyl group or an aliphatic hydrocarbon group having a hydroxyl group as a substituent include the following.

  Examples of Y having an aromatic hydrocarbon group having an alkyl group as a substituent include the following.

Examples of Y having a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 as a substituent include the following.

  Y is preferably an adamantyl group which may have a hydroxy group or the like as a substituent, and more preferably an adamantyl group or a hydroxyadamantyl group.

As the sulfonate anion, in formula (B1), it is preferable that L ^b1 is a group represented by formula (b1-1), and formula (b1-1-1), formula (b1-1-2), Formula (b1-1-3), Formula (b1-1-4), Formula (b1-1-5), Formula (b1-1-6), Formula (b1-1-7), Formula (b1-1 -8) and formula (b1-1-9) [hereinafter expressed as “formula (b1-1-1) to formula (b1-1-9)”. ] Is more preferable. In the sulfonate anion represented by any one of the formulas (b1-1-1) to (b1-1-9), R ^b2 and R ^b3 may be independently selected within the range of Y. And an aliphatic hydrocarbon group having 1 to 4 carbon atoms is preferable, and a methyl group is particularly preferable.

Hereinafter, specific sulfonate anions are exemplified. Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y is unsubstituted or has an aliphatic hydrocarbon group as a substituent include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y has a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 as a substituent include, for example, Can be mentioned.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y has a hydroxyl group or an aliphatic hydrocarbon group having a hydroxyl group as a substituent include the following. It is done.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y has an aromatic hydrocarbon group or an aralkyl group as a substituent include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y is a cyclic ether group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y is a lactone ring group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y is a cyclic ketone group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y is a sultone ring group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y is unsubstituted or has an aliphatic hydrocarbon group as a substituent include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y has a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 as a substituent include, for example, Can be mentioned.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y has a hydroxyl group or an aliphatic hydrocarbon group having a hydroxyl group as a substituent include the following. It is done.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y has an aralkyl group as a substituent include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y is a cyclic ether group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y is a lactone ring group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y is a cyclic ketone group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-2) and Y is a sultone ring group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-3) and Y is unsubstituted or has an aliphatic hydrocarbon group as a substituent include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-3) and Y has a hydroxyl group or an aliphatic hydrocarbon group having a hydroxyl group as a substituent include the following. It is done.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-3) and Y is a cyclic ketone group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-4) and Y has an aliphatic hydrocarbon group as a substituent include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-4) and Y has an alkoxy group include the following.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-4) and Y has a hydroxyl group or an aliphatic hydrocarbon group having a hydroxyl group as a substituent include the following. It is done.

Examples of the sulfonate anion in which L ^b1 is a group represented by the formula (b1-4) and Y is a cyclic ketone group include the following.

Among the sulfonate anions exemplified above, those in which L ^b1 is a group represented by the formula (b1-1) are preferable. More preferred sulfonate anions are shown below.

  Examples of the cation contained in the acid generator include onium cation, sulfonium cation, iodonium cation, ammonium cation, benzothiazolium cation, and phosphonium cation. Among these, a sulfonium cation and an iodonium cation are preferable, and an arylsulfonium cation is more preferable.

The organic cation (Z ⁺ ) in the acid generator (B1) is also preferably a sulfonium cation and an iodonium cation, and more preferably the following formulas (b2-1), (b2-2), and (b2-3) And formula (b2-4) [hereinafter expressed as “formula (b2-1) to formula (b2-4)”. ] In accordance with the number of each formula, “cation (b2-1)”, “cation (b2-2)”, “cation (b2-3)” and “cation” (B2-4) ". ].

In Formula (b2-1), R ^b4 , R ^b5, and R ^b6 are each independently an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 6 carbon atoms. Represents an aromatic hydrocarbon group of ˜18. The aliphatic hydrocarbon group may have a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group is a halogen atom. May have an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, or 3 carbon atoms. It may have an -18 alicyclic hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms.

In Formula (b2-2), R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.

In Formula (b2-3), R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b9 , R ^b10 and R ^b11 (hereinafter referred to as “R ^{b9 to} R ^b11 ”) are each independently an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and these are aliphatic. When it is a hydrocarbon group, its carbon number is preferably 1-12, and when it is an alicyclic hydrocarbon group, its carbon number is preferably 3-18, more preferably 4-12.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyl having 1 to 12 carbon atoms. It may have an oxy group.
The combination of R ^b9 and R ^b10 and / or the combination of R ^b11 and R ^b12 are independently bonded to each other to form a 3-membered ring to 12-membered ring (preferably a 3-membered ring to 7-membered ring). These 3-membered ring to 12-membered ring (preferably 3-membered ring to 7-membered ring) may be an alicyclic ring or a methylene group contained in the alicyclic ring is an oxy group, a thioxy group or a carbonyl group. The ring is replaced with.

In the formula ^{(2-4), R b13, R} b14, R b15, R b16, R b17 and R ^b18 (hereinafter, may be referred to as "R ^b13 to R ^b18".) Each independently hydroxy Group, a C1-C12 aliphatic hydrocarbon group or a C1-C12 alkoxy group.
L ^b11 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are independent, when p2 is 2 or more, the plurality of R ^b14 are independent, and when q2 is 2 or more, the plurality of R ^b15 are independent. , R2 is 2 or more, each of R ^b16 is independent, when s2 is 2 or more, each of R ^b17 is independent, and when t2 is 2 or more, each of R ^b18 is independent. is there.

^Examples of the alkylcarbonyloxy group for R ^b12 include methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butyl. Examples thereof include a carbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

^Among the aliphatic hydrocarbon groups ^{represented by} R ^{b9 to} R ^b12 , preferred groups are, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, A hexyl group, an octyl group, a 2-ethylhexyl group, and the like.
Among the alicyclic hydrocarbon groups represented by R ^{b9 to} R ^b11 , preferred groups are, for example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group and isobornyl group.

^Among the aromatic hydrocarbon groups ^represented by R ^b12 , preferred groups are, for example, phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl. Group, biphenylyl group and naphthyl group.
The aromatic hydrocarbon group having an aliphatic hydrocarbon group represented by R ^b12 is typically an aralkyl group, and specific examples include a benzyl group.

Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the exemplified organic cations, the cation (b2-1) is preferable, and an organic cation represented by the following formula (b2-1-1) [hereinafter referred to as “cation (b2-1-1)”. ], More preferably a triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = X2 = 1, and R ¹⁹ , R ²⁰ and R ²¹ are all methyl groups). A resist composition containing such an acid generator (B1) having an organic cation can produce a resist pattern with a better focus margin.

In formula (b2-1-1), R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, carbon An alicyclic hydrocarbon group having 3 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms is represented.
The aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, and further, as a substituent, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or a carbon number. It may have 6-18 aromatic hydrocarbon groups. The alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms and may have a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group as a substituent.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, each of the plurality of R ^b19 is independent. When w2 is 2 or more, each of the plurality of R ^b20 is independent. When x2 is 2 or more, each of the plurality of R ^b21 is independent. .
Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It is a group.

  Specific examples of the cation (b2-1-1) include the following.

The cation (b2-1-1) which is already a suitable organic cation and specific examples thereof have been shown. Specific examples of the cation (b2-2), cation (b2-3) and cation (b2-4) are also shown. Let me show you.
Specific examples of the cation (b2-2) include the following.

  Specific examples of the cation (b2-3) include the following.

  Specific examples of the cation (b2-4) include the following.

  The acid generator (B1) has been described for each of the sulfonate anion and the organic cation constituting the acid generator (B1). The acid generator (B1) is a combination of the sulfonate anion and the organic cation. The sulfonate anion and the organic cation can be arbitrarily combined, but the sulfonate anion and cation (b2-) represented by any one of the formulas (b1-1-1) to (b1-1-9) can be used. 1-1) is an acid generator (B1) in combination with the sulfonate anion and cation (b2-3) represented by any one of formulas (b1-1-3) to (b1-1-5) The acid generator (B1) which is a combination with) is preferred. The resist composition containing such an acid generator (B1) can produce a resist pattern with a wider focus margin.

  More preferred acid generator (B1) is specifically shown. Such an acid generator (B1) has the following formula (B1-1), formula (B1-2), formula (B1-3), formula (B1-4), formula (B1-5), formula (B) B1-6), formula (B1-7), formula (B1-8), formula (B1-9), formula (B1-10), formula (B1-11), formula (B1-12), formula (B1) −13), Formula (B1-14), Formula (B1-15), Formula (B1-16), and Formula (B1-17). Among them, the acid generator (B1) containing a triphenylsulfonium cation is the formula (B1-1), formula (B1-2), formula (B1-6), formula (B1-11), formula (B1-12). And those represented by any of formulas (B1-13) and (B1-14) are more preferred.

<Photobase generator>
The resist composition contains a photobase generator (hereinafter referred to as “photobase generator (G)”). The photobase generator generates a base upon irradiation with radiation. Examples of such a photobase generator (G) include compounds that generate a base by radiation described in JP-A-2005-17354, JP-A-2005-60520, and the like. Can be used as

  Examples of the photobase generator (G) preferably used in the present invention include compounds represented by the following formula (II) and compounds represented by the formula (III).

[In the formula (II),
R ³ represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ⁴ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group includes an alkyl group having 1 to 6 carbon atoms and an alicyclic carbon atom having 3 to 20 carbon atoms. It may be substituted with a hydrogen group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a nitro group, a hydroxyl group or a cyano group.
R ⁵ represents an alkyl group having 1 to 6 carbon atoms, a saturated hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and the saturated hydrocarbon —CH ₂ — contained in the group may be replaced by —O—, —CO— or —SO ₂ —. ]

[In the formula (III),
R ⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
R ⁷ represents a hydrocarbon group having 1 to 20 carbon atoms.
R ⁸ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group includes an alkyl group having 1 to 6 carbon atoms and an alicyclic carbon atom having 3 to 20 carbon atoms. It may be substituted with a hydrogen group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a nitro group, a hydroxyl group or a cyano group.
R ⁹ represents an alkyl group having 1 to 6 carbon atoms, a saturated hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and the saturated hydrocarbon —CH ₂ — contained in the group may be replaced by —O—, —CO— or —SO ₂ —. ]

Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms in R ³ include the following groups.

Examples of the fluorinated alkyl group having 1 to 6 carbon atoms in R ³ include the following groups.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms in R ⁴ and R ⁸ include the following groups.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms substituted with an alkyl group having 1 to 6 carbon atoms in R ⁴ and R ⁸ include the following groups. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms that is substituted with the alicyclic hydrocarbon group having 3 to 20 carbon atoms in R ⁴ and R ⁸ include the following groups. The alicyclic hydrocarbon group having 3 to 20 carbon atoms, for example, the groups exemplified as the above R ^3.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms that is substituted with the aromatic hydrocarbon group having 6 to 20 carbon atoms in R ⁴ and R ⁸ include the following groups. Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include the same groups as described above.

As a C6-C20 aromatic hydrocarbon group substituted by the halogen atom in R < ⁴ > and R < ⁸ >, the following groups are mentioned, for example.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms substituted with a nitro group, a hydroxyl group or a cyano group in R ⁴ and R ⁸ include the following groups.

Examples of the saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms in R ⁵ and R ⁹ include a fluorinated alkyl group having 1 to 20 carbon atoms. As the fluorinated alkyl group having 1 to 20 carbon atoms, For example, the following groups are mentioned.

Of the saturated hydrocarbon groups having 1 to 20 carbon atoms in R ⁵ and R ^{9, as} the group in which —CH ₂ — is replaced by —O—, —CO— or —SO ₂ —, for example, The group of is mentioned.

Examples of the aromatic hydrocarbon group having a fluorine atom having 6 to 20 carbon atoms in R ⁵ and R ⁹ include the following groups.

R ⁵ and R ⁹ are preferably a fluorinated alkyl group having 1 to 4 carbon atoms, more preferably a fluorinated alkyl group having 1 or 2 carbon atoms, and particularly preferably a trifluoromethyl group.

Examples of compounds represented by formula (II) are shown in Table 1.
For example, “II-1” in the table means “compound represented by the formula (II-1)”, specifically, in the formula (II), R ³ is represented by the formula (R ³ -1). Means a compound in which R ⁴ is a group represented by the formula (R ⁴ -1) and R ⁵ is a group represented by the formula (R ⁵ -1).

  Of the above compounds, the compound represented by formula (II-3), the compound represented by formula (II-6), the compound represented by formula (II-15), and the formula (II-24) The compound represented by formula (II-46), the compound represented by formula (II-59) or the compound represented by formula (II-70) is preferred, more preferably formula (II-3) A compound represented by formula (II-6), or a compound represented by formula (II-24).

The compound represented by the formula (II) can be produced, for example, as follows.
Examples of the method for producing the compound represented by the formula (II) include, for example, an oxime derivative represented by the formula (IV) and a carboxylic acid derivative represented by the formula (V), such as chloroform, methylene chloride, Examples thereof include a method of reacting under an inert solvent such as ethylene chloride, monochlorobenzene, acetone, methyl ethyl ketone, toluene, xylene, anisole, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide under basic conditions. The reaction temperature is, for example, -30 to 200 ° C, preferably -20 to 150 ° C. Examples of the base include trimethylamine, triethylamine, piperidine, N-methylpiperidine, pyrrolidine, N-methylpyrrolidine, pyridine, N, N-dimethylaminopyridine, lutidine and the like.

[Wherein R ³ , R ⁴ and R ⁵ represent the same meaning as described above.
X represents a fluorine, chlorine, bromine or iodine atom. ]

  The amount of the carboxylic acid derivative represented by the formula (V) is, for example, 0.5 to 5 times, preferably 0.8 to 2 times the amount of the oxime derivative represented by the formula (IV). It is a molar amount, and the usage-amount of a dehydrating agent is 1-3 times mole amount, for example, Preferably it is 1-2 times mole amount. The obtained compound represented by the formula (II) can be taken out by ordinary post-treatment. The compound represented by the formula (II) may be taken out by recrystallization or purified by column chromatography.

  As a method for producing the compound represented by the formula (II), for example, an oxime derivative represented by the formula (IV) and a carboxylic acid represented by the formula (VI) can be used, for example, chloroform, methylene chloride, dichloride. Examples thereof include a reaction method in the presence of a dehydrating agent in an inert solvent such as ethylene, monochlorobenzene, acetone, methyl ethyl ketone, toluene, xylene, anisole, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide. The reaction temperature is, for example, -30 to 200 ° C, preferably -20 to 150 ° C. Examples of the dehydrating agent include dicyclohexylcarbodiimide, 1-alkyl-2-halopyridinium salt, 1,1-carbonyldiimidazole, bis (2-oxo-3-oxazolidinyl) phosphine acid chloride, 1-ethyl-3- ( 3-dimethylaminopropyl) carbodiimide hydrochloride, di-2-pyridyl carbonate, di-2-pyridylthiono carbonate, 6-methyl-2-nitrobenzoic anhydride / 4- (dimethylamino) pyridine (catalyst) It is done.

[Wherein R ³ , R ⁴ and R ⁵ represent the same meaning as described above. ]

  The used amount of the carboxylic acid represented by the formula (VI) is, for example, 0.5 to 5 times mole amount, preferably 0.8 to 2 times mole based on 1 mole of the oxime derivative represented by the formula (IV). The amount of the dehydrating agent used is, for example, 1 to 3 times the molar amount, preferably 1 to 2 times the molar amount. The obtained compound represented by the formula (II) can be taken out by ordinary post-treatment. The compound represented by the formula (II) may be taken out by recrystallization or purified by column chromatography.

In formula (III), examples of the alkyl group having 1 to 6 carbon atoms represented by R ⁶ include a methyl group, an ethyl group, a propyl group, and a butyl group. R ⁶ is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

In the formula (III), the hydrocarbon group having 1 to 20 carbon atoms represented by R ⁷ is an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or 6 to 6 carbon atoms. Examples include 20 aromatic hydrocarbon groups or groups in which these substituents are linked. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms include a cyclohexyl group, a cyclopentyl group, and an adamantyl group. Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group and a naphthyl group. Examples of the group to which the substituent is linked include a benzyl group.

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

<Compound represented by formula (I)>
The resist composition of the present invention contains a compound represented by formula (I) (hereinafter sometimes referred to as “compound (H) represented by formula (I)”).

[In Formula (I), R ¹ and R ² each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms or a heterocyclic group, or are connected to each other to form a ring. ]

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, an alkenyl group, a cycloalkyl group, and an aryl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an n-pentyl group. Examples of the alkenyl group include a vinyl group, an allyl group, a 2-butenyl group, and a 1,3-butadienyl group. Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. As an aryl group, a phenyl group, 2-chlorophenyl group, 4-methoxyphenyl group, 3-methylphenyl group, 1-naphthyl group, 2-naphthyl group etc. are mentioned, for example.
As a C1-C12 hydrocarbon group, an alkyl group and a cycloalkyl group are preferable, and a C1-C6 alkyl group is more preferable. The alkyl group may be linear or branched. More preferably, they are a methyl group, an ethyl group, a cyclohexyl group, or a cyclopentyl group.

  Examples of the heterocyclic group include pyridyl group, thienyl group, furyl group, thiazolyl group, imidazolyl group, pyrazolyl group, pyrrolidino group, piperidino group, morpholino group and the like.

Examples of the ring formed by connecting R ¹ and R ² to each other include a piperidine ring, a pyrrolidine ring, a piperazine ring, a morphophore ring, a pyridine ring, a quinoline ring, and an imidazole ring. The ring formed by connecting R ¹ and R ² to each other is more preferably a piperidine ring, a pyrrolidine ring, or an imidazole ring, and most preferably a piperidine ring.

As a more preferable combination of R ¹ and R ² , R ¹ is an optionally substituted cyclohexyl group and R ² is a hydrogen atom; R ¹ is an optionally substituted alkyl group and R ^2. Is a hydrogen atom; R ¹ and R ² are linked to form a piperidine ring or an imidazole ring.

  As the compound (H) represented by the formula (I), the following compounds are preferable.

  The compound (H) represented by the formula (I) is produced, for example, by reacting 9-hydroxymethyl-9H-fluorene with a chloroformate to synthesize a carbonic acid diester and reacting the carbonic acid diester with a base. be able to.

<Solvent>
The solvent (hereinafter referred to as “solvent (D)”) contained in the resist composition is represented by the resin (A), the acid generator (B), the photobase generator (G), and the formula (I). It can be selected according to the type and amount of each component of the compound (H), and, in the production of a resist pattern, which will be described later, the applicability when applying the resist composition on the substrate is suitably selected. , You can choose the best one.

  Examples of the solvent (D) 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 pyruvic acid. Examples thereof include esters such as ethyl; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; Only 1 type may be used for a solvent (D) and it may use 2 or more types together.

<Other ingredients>
The present resist composition may be used in addition to the resin (A), the acid generator (B), the photobase generator (G), the compound (H) represented by the formula (I), and the solvent (D) as necessary. A component may be included. This component is referred to as “component (F)”. Such component (F) is an additive widely used in this technical field, and examples thereof include a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye.

<This resist composition and its preparation method>
This resist composition is prepared by mixing the resin (A), the acid generator (B), the photobase generator (G), the compound (H) represented by the formula (I) and the solvent (D). be able to. Further, the component (F) may be mixed as described above. In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing is from 10 to 40 ° C., and the acid generator (B), photobase generator (G), compound (H) represented by the formula (I), etc. An appropriate temperature range can be selected according to the solubility in the solvent (D) such as (B), the photobase generator (G), and the compound (H) represented by the formula (I). 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.

  Next, in the present resist composition, a preferred content mass of the resin (A), the acid generator (B), the photobase generator (G), the compound (H) represented by the formula (I), and the solvent (D). The ratio (hereinafter sometimes referred to as “content”) will be described.

As described above, the content of the solvent (D) can be appropriately adjusted according to the type of the acid generator (B), the photobase generator (G), the compound (H) represented by the formula (I), and the like. The content is preferably 90% by mass or more based on the total mass of the resist composition. In addition, in this resist composition whose content of a solvent (D) is 90 mass%, content of solid content with respect to this resist composition total mass corresponds to 10 mass%. This resist composition containing the solvent (D) with such a content is suitable as a thin film resist capable of forming a composition layer having a thickness of about 30 to 300 nm, for example, in a method for producing a resist pattern described later. From this viewpoint, the content of the solvent (D) with respect to the total mass of the resist composition is more preferably 92% by mass or more, and still more preferably 94% by mass or more. The upper limit of the content of the solvent (D) is, for example, 99.9% by mass or less, and preferably 99% by mass or less.
The content of the solvent (D) can be controlled by the amount of the solvent (D) used in preparing the resist composition. After preparing the resist composition, the resist composition It can also be obtained by using a known analytical means such as liquid chromatography or gas chromatography.

  A preferable range of the content of the resin (A) in the resist composition is selected with respect to the total mass of the solid content of the resist composition. Specifically, the content of the resin (A) with respect to the total mass of the solid content is preferably 80% by mass or more. In addition, solid content is a component except the solvent (D) among the components contained in a resist composition.

  A preferable range of the content of the acid generator (B) in the resist composition is selected with respect to the total mass of the resin (A) contained in the resist composition. Specifically, the acid generator (B) is preferably 1 part by mass or more and more preferably 3 parts by mass or more with respect to 100 parts by mass of the resin (A). The acid generator (B) is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, relative to 100 parts by mass of the resin (A).

  A preferable range of the content of the photobase generator (G) in the resist composition is selected with respect to the total mass of the solid content of the resist composition. Specifically, the content of the photobase generator (G) with respect to the total mass of the solid content is preferably 0.01 to 3% by mass, and more preferably 0.05 to 1% by mass.

  A preferable range of the content of the compound (H) represented by the formula (I) in the resist composition is selected with respect to the total mass of the solid content of the resist composition. Specifically, the content of the compound (H) represented by the formula (I) with respect to the total mass of the solid content is preferably 0.01 to 3% by mass, and more preferably 0.05 to 1% by mass. .

  The mass ratio ((G) / (H)) between the photobase generator (G) and the compound (H) represented by the formula (I) is preferably 0.1 or more, more preferably 0.2. As mentioned above, More preferably, it is 0.3 or more, 10 or less is preferable, More preferably, it is 7 or less, More preferably, it is 4 or less.

  The preferred content of each of these resins (A), acid generator (B), photobase generator (G) and compound (H) represented by formula (I) is also determined when preparing the resist composition. It is controllable by each usage amount. After the present resist composition is prepared, the present resist composition can be obtained by subjecting it to a known analysis means such as gas chromatography or liquid chromatography.

In addition, when using a component (F) for this resist composition, suitable content can also be adjusted according to the kind of the said component (F).
Thus, each of resin (A), acid generator (B), photobase generator (G), compound (H) represented by formula (I) and solvent (D), or component (F) After mixing at a preferred content, the resist composition can be prepared by filtration using a filter having a pore size of about 0.2 μm.

<Method for producing resist pattern>
Then, the manufacturing method of the resist pattern using this resist composition is demonstrated.
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition on a substrate;
(2) forming a composition layer on the substrate by removing the solvent from the resist composition applied on the substrate;
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) It includes a step of developing the composition layer after heating. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

  Application of the resist composition on the substrate in the step (1) can be performed by a coating apparatus widely used for applying a resist material for semiconductor microfabrication, such as a spin coater. Thus, a coating film made of a resist composition is formed on the substrate. The film thickness of the coating film can be adjusted by appropriately adjusting the conditions (coating conditions) of the coating apparatus, and by applying an appropriate preliminary experiment, the coating film can be applied to have a desired film thickness. You can choose the conditions. Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. The substrate can be washed or an antireflection film can be formed before applying the resist composition. For example, a commercially available composition for an organic antireflection film can be used for forming the antireflection film.

In the step (2), the solvent [solvent (D)] is removed from the resist composition coated on the substrate, that is, the coated film. Such solvent removal is performed, for example, by evaporating the solvent from the coating film by a heating means using a heating device such as a hot plate, a decompression means using a decompression device, or a combination of these means. Is called. The conditions of the heating means and the decompression means are adjusted according to the type of the solvent (D) contained in the resist composition. For example, in the heating means using a hot plate (hot plate heating), the surface of the hot plate What is necessary is just to make temperature into the range of about 50-200 degreeC. In the decompression means, after the substrate on which the coating film is formed is sealed in an appropriate decompressor, the internal pressure of the decompressor may be set to about 1 to 1.0 × 10 ⁵ Pa. By removing the solvent from the coating film in this way, a composition layer is formed on the substrate.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask corresponding to a desired pattern to be finely processed. As an exposure light source of the exposure machine, an ultraviolet light emitting device such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ laser (wavelength 157 nm), a solid-state laser light source (YAG or Various lasers such as those that emit laser light from a far ultraviolet region or a vacuum ultraviolet region by converting the wavelength of laser light from a semiconductor laser or the like can be used. The exposure machine may be an immersion exposure machine.
As described above, by exposing through a mask, an exposed portion (exposed portion) and an unexposed portion (unexposed portion) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator (B) contained in the composition layer generates an acid upon receiving exposure energy, and further, an acid labile group in the resin (A) is generated by the action with the generated acid. Causes a deprotection reaction, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in an alkaline aqueous solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Therefore, the composition layer in the exposed part and the composition layer in the unexposed part are significantly different in solubility in the alkaline aqueous solution.

  In step (4), a heat treatment for further promoting the progress of the deprotecting group reaction that may occur in the exposed portion is performed. For this heat treatment, the heating means using the hot plate shown in the step (2) is adopted. In the hot plate heating in step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with a developing device. The development referred to here is by bringing the composition layer after heating into contact with an alkaline aqueous solution, thereby dissolving the exposed composition layer in the alkaline aqueous solution and leaving the unexposed composition layer on the substrate. A resist pattern is manufactured on the substrate.
The alkaline aqueous solution used here is referred to as “alkaline developer”, and those used in this technical field can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).

  The resist pattern manufactured on the substrate as described above is preferably rinsed with ultrapure water or the like to further remove moisture remaining on the substrate and the resist pattern.

<Application>
The resist composition includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for EB or a resist composition for EUV exposure machines, and chemical amplification for immersion exposure. It is suitable as a type positive resist composition.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention. In the following, “%” and “part” representing the content or amount used are based on mass unless otherwise specified.

  The composition ratio of the resin (A) (copolymerization ratio of the structural unit derived from each monomer used for the production of the resin (A) to the resin (A)) is the amount of unreacted monomer in the reaction solution after the completion of polymerization. The measurement was performed using a graph, and the amount of monomer used for the polymerization was determined from the obtained results.

The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: "TSKgel Multipore HXL-M" (manufactured by Tosoh Corporation) x 3 and "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)

  The structure of the compound was confirmed by mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).

Synthesis Example 1 (Synthesis of photobase generator (G))
To a solution of 5.0 parts of the compound represented by the formula (II-24-a) and 25 parts of tetrahydrofuran, 2.9 parts of N-methylpyrrolidone is added and cooled to 5 ° C., and the formula (II-24-b 6.3 parts of the compound represented by) was added, followed by stirring at room temperature for 3 hours. 21 parts of a 5% aqueous hydrochloric acid solution and 20 parts of ion-exchanged water were added to the reaction mixture, and extraction was performed with 100 parts of ethyl acetate. 15 parts of 10% aqueous potassium carbonate solution was added to the organic layer containing ethyl acetate and stirred overnight, and then the aqueous layer was discharged. The obtained organic layer was washed with ion exchanged water and concentrated under reduced pressure to obtain 8.9 parts of a compound represented by the formula (II-24).

Physical property data MS (ESI (+) Spectrum) of compound (II-24): [M + K] ⁺ = 390.1 (C ₁₉ H ₂₀ F ₃ NO ₂ = 351.1)

Synthesis Example 2 (Synthesis of resin (A))
The compounds (monomers) used in the resin synthesis are shown below. Hereinafter, for these monomers, for example, a compound represented by the formula (a1-1-1) is referred to as “monomer (a1-1-1)”.

[Synthesis of Resin A1]
The monomer (a1-1-2), monomer (a1-2-1), monomer (a2-1-1), monomer (a2-1-2) and monomer (a3-2-1) are mixed in a molar ratio [ Monomer (a1-1-2): monomer (a1-2-1): monomer (a2-1-1): monomer (a2-1-2): monomer (a3-2-1)] is 50:10 : 4: 5.5: 30.5 The mixture was further mixed, and 1.5 mass times of dioxane was further mixed with this monomer mixture with respect to the total mass of all monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 3.0 mol% and 9.0 mol, respectively, based on the total number of moles of all monomers. %, And the mixture was heated at 75 ° C. for about 5 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of methanol to precipitate the resin. This resin is filtered and recovered, dissolved again in dioxane, poured into a large amount of methanol to precipitate the resin, and the precipitated resin is filtered and recovered twice, followed by reprecipitation purification and weight average molecular weight. Of about 3.6 × 10 ³ was obtained in a yield of 68%.
This copolymer comprises monomer (a1-1-2), monomer (a1-2-1), monomer (a2-1-1), monomer (a2-1-2) and monomer (a3-2-1). The molar ratio [monomer (a1-1-2): monomer (a1-2-1): monomer (a2-1-1): monomer (a2- 1-2): Monomer (a3-2-1)] was 41.4: 10.5: 4.7: 6.7: 36.7. This is designated as resin A1.

[Synthesis of Resin A2]
The monomer (a1-1-1), monomer (a2-1-1) and monomer (a3-1-1) are mixed in a molar ratio [monomer (a1-1-1): monomer (a2-1-1): Monomer (a3-1-1)] was mixed so as to be 50:25:25, and 1.5 mass times dioxane was further mixed with respect to the total mass of all monomers. In the resulting mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers Polymerization was carried out by heating at 80 ° C. for about 8 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin is filtered and collected, dissolved again in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and collected three times for reprecipitation. Purification gave a copolymer having a weight average molecular weight of about 9.2 × 10 ³ in a yield of 60%.
This copolymer has structural units derived from the following monomers derived from the monomer (a1-1-1), the monomer (a2-1-1) and the monomer (a3-1-1), respectively. The molar ratio [monomer (a1-1-1): monomer (a2-1-1): monomer (a3-1-1)] was 42.6: 28.7: 28.7. This is called Resin A2.

Preparation of Compound (H) Represented by Formula (I) A compound represented by formula (I-1) (trade name: N-Fmoc-ethanolamine, manufactured by Aldrich) was prepared.

Examples 1 to 4 and Comparative Example 1
<Preparation of resist composition>
Each of Resin A1 and Resin A2 obtained in Synthesis Example 2, acid generator B1 shown below, photobase generator G1 obtained in Synthesis Example 1, and compound H1 represented by Formula (I) shown below In parts by mass shown in Table 9, the resist composition was dissolved in the following solvent, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

<Resin (A)>
A1: Resin A1 (see Synthesis Example 2)
A2: Resin A2 (see Synthesis Example 2)
<Acid generator (B)>
B1: Salt represented by the formula (B-1)

<Photobase generator (G)>
G1: Compound represented by formula (II-24) (see Synthesis Example 1)

<Compound (H) Represented by Formula (I)>
H1: Compound represented by formula (I-1)

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

<Manufacture of resist pattern and its evaluation>

An organic antireflection film having a thickness of 780 mm is formed by applying a composition for organic antireflection film (ARC-29; manufactured by Nissan Chemical Co., Ltd.) to a silicon wafer and baking it at 205 ° C. for 60 seconds. Formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying was 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate for 60 seconds at the temperature described in the “ _TPB ” column of Table 9 to form a resist film. ArF excimer stepper for immersion exposure (XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which a resist film is formed, and a contact hole pattern (hole pitch 100 nm / Using a mask for forming a hole diameter of 70 nm, exposure was performed while changing the exposure amount stepwise.
After the exposure, the silicon wafer was post-exposure baked on a hot plate for 60 seconds at the temperature described in the “ _TPEB ” column of Table 9. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution. In each resist film, an exposure amount at which the hole diameter of a pattern formed with a mask having a hole diameter of 70 nm was 55 nm was defined as effective sensitivity.
In manufacturing the resist pattern as described above, the following items were evaluated.

<Resolution evaluation>
In terms of effective sensitivity, the following three levels were evaluated with reference to a pattern in which a hole diameter of a pattern formed with a mask having a hole diameter of 70 nm is resolved to 55 nm.
That is, the case where the hole diameter of a pattern formed with a mask having a hole diameter of 67 nm is 50 nm or more is “◎”, the case where it is 30 nm or more and less than 50 nm is “◯”, and the case where it is less than 30 nm is “×”.
The results of the resolution evaluation obtained as described above are expressed by the above-mentioned level evaluation and are summarized in Table 10.

  As described above, the resist composition of the present invention containing the photobase generator (G) and the compound (H) represented by the formula (I) has a resolution of “◯” or “◎”. A resist pattern with good resolution could be manufactured. On the other hand, the resolution of the resist composition of Comparative Example 1 was (x).

  According to the resist composition of the present invention, a resist pattern having excellent resolution can be produced.

Claims (3)

A resist comprising a resin that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid, an acid generator, a photobase generator, a compound represented by formula (I), and a solvent Composition.

[In Formula (I), R ¹ and R ² each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms or a heterocyclic group, or are bonded to each other to form a ring. ] The resist composition according to claim 1, wherein the photobase generator is a compound represented by the formula (II).

[In Formula (II), R ³ represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ⁴ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group includes an alkyl group having 1 to 6 carbon atoms and an alicyclic carbon atom having 3 to 20 carbon atoms. It may be substituted with a hydrogen group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a nitro group, a hydroxyl group or a cyano group.
R ⁵ represents an alkyl group having 1 to 6 carbon atoms, a saturated hydrocarbon group having a fluorine atom having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms having a fluorine atom, and the saturated hydrocarbon —CH ₂ — contained in the group may be replaced by —O—, —CO— or —SO ₂ —. ] (1) The process of apply | coating the resist composition of Claim 1 or 2 on a board | substrate,
(2) forming a composition layer on the substrate by removing the solvent from the resist composition coated on the substrate;
(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;
A method for producing a resist pattern including: