JP2003084436A - Chemical amplification type resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical amplification type resist composition excellent in resolution, lowering of line edge roughness and rectangularity of a resist pattern in section. SOLUTION: The chemical amplification type resist composition is obtained by dissolving in an organic solvent (A) a (meth)acrylic acid copolymer having an ester of acrylic acid and a specified monocyclohexane or bicycloheptane carbolactone or the like as repeating units and having a molecular weight distribution of 1.01-1.50 and (B) a compound which generates an acid when irradiated with radiation.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention comprises a (meth) acrylic acid copolymer having a narrow molecular weight distribution for improving the resolution, reducing the line edge roughness, and improving the rectangularity of a sectional resist pattern. The present invention relates to a chemically amplified resist composition having excellent properties.

[0002]

2. Description of the Related Art Recently, as a base resin for a chemically amplified resist, particularly as a resist for ArF, it does not have an aromatic group such as a hydroxystyrene monomer unit having an absorption at 193 nm and does not have an adamantyl group. A large number of aliphatic polycyclic group-containing (meth) acrylic acid copolymers having an aliphatic polycyclic group in the side chain and improved dry etching properties have been proposed (Patent No. 2881969, JP-A-5-3).
46668, JP 7-234511 A, JP 10-319595 A, JP 2001-209 A.
No. 254, etc.).

[0003]

However, such a conventional (meth) acrylic acid copolymer has a wide molecular weight distribution, and a chemically amplified resist using such a (meth) acrylic acid copolymer cannot be obtained. Nowadays, as the miniaturization of semiconductor devices progresses, the resolution is no longer sufficient. Further, as the resist pattern size is further miniaturized, the demand for line edge roughness reduction becomes more severe than before, and there is a problem that the resist cross-sectional shape also causes a slight footing at the substrate interface. It is strongly desired to solve such problems.

Therefore, it is an object of the present invention to provide a resist composition which is excellent in resolution, reduces line edge roughness and rectangularity of a sectional resist pattern.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that an ester of a narrowly dispersible (meth) acrylic acid and a specific monocyclohexane or bicycloheptanecarbolactone is used. By using a (meth) acrylic acid copolymer as a repeating unit as a resin whose alkali solubility is increased by the action of an acid, the resist has excellent resolution, reduced line edge roughness, and excellent rectangularity in the cross-sectional resist pattern. They have found that a composition can be obtained and completed the present invention.

That is, according to the present invention, the following components (A) and (B) (A)

[0007]

[Chemical 9]

(In the formula, R ₁ represents a hydrogen atom or a C1 to C5 alkyl group which may have a substituent, and A 1
Represents a single bond, an alkyleneoxyalkylene group, a carbonyloxy group, an oxycarbonyl group, a carbonyl group, an alkylene group, or a divalent group combining these,
B is the formula (I-1) to (I-4)

[0009]

[Chemical 10]

(In the formula, X represents an oxygen atom, a sulfur atom or an alkylene group which may have a substituent, and R
₂ represents an alkyl group which may have a substituent, a cycloalkyl group or an alkenyl group, and m is 0 or 1
Represents any integer of 5 to 5, and when m is 2 or more, R ₂
May be the same or different, and may be bonded to each other to form a ring. ) Represents a substituent. ), And the ratio (Mw / M) of the weight average molecular weight (Mw) and the number average molecular weight (Mn).
Chemically amplified resist composition obtained by dissolving (meth) acrylic acid copolymer having n of 1.01 to 1.50 and (B) a compound capable of generating an acid upon irradiation with radiation in an organic solvent. Is provided.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present specification, the term "(meth) acrylic acid copolymer" means a copolymer derived from methacrylic acid ester and / or acrylic acid ester. The component (A) used in the present invention has a molecular weight distribution (weight average molecular weight (Mw) to number average molecular weight (Mn) ratio (M).
(w / Mn)) is a narrow (meth) acrylic acid copolymer of 1.01 to 1.50. In the conventional anionic polymerization method, it has been considered difficult to obtain a random copolymer having a narrow molecular weight distribution because the reactivity of two or more (meth) acrylic acid esters to be used is greatly different. However, by using an appropriate amount of an alkali metal salt and / or an alkaline earth metal salt of a mineral acid with respect to the anionic polymerization initiator, the molecular weight distribution is narrow even when the reactivity of the (meth) acrylic acid ester is significantly different. A (meth) acrylic acid copolymer can be produced.

The component (A) used in the present invention has a repeating unit of a (meth) acrylic acid ester having a lactone ring. Specifically, it has a repeating unit represented by the formula (I). It is a (meth) acrylic acid copolymer. In the repeating unit represented by the formula (I), R ₁ represents a hydrogen atom or a C1 to C5 alkyl group which may have a substituent, and A represents a single bond, an alkyleneoxyalkylene group or carbonyloxy. Represents a group, a carbonyl group, an alkylene group, or a divalent group in which these groups are combined, and B is
It represents any of the substituents represented by formulas (I-1) to (I-4).

Specific examples of R ₁ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group and the like. . In formulas (I-1) to (I-4), X represents an oxygen atom, a sulfur atom or an alkylene group which may have a substituent, and specifically, an oxygen atom, a sulfur atom, a methylene group. , Ethylene group, 1,1-dimethylmethylene group, 1,2-dimethylethylene group, 1,
A 1-dimethyl ethylene group etc. can be illustrated. R
₂ represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group, or an alkenyl group, and m
Represents an integer of 0 to 5, and when m is 2 or more, R _{2 s} may be the same or different,
Further, they may be bonded to each other to form a ring. The alkyl group for R ₂ is linear or branched C1 to C1.
The alkyl group of 2 is preferable, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group,
Isobutyl group, sec-butyl group, t-butyl group, n-
Examples thereof include a pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group and n-decyl group.

Specific examples of the cycloalkyl group include cyclopropyl group, cyclopentyl group, cyclohexyl group,
C3-C8 such as cycloheptyl group and cyclooctyl group
Examples thereof include vinyl groups, 2-propenyl groups, 2-butenyl groups, and 3 as alkenyl groups.
Examples thereof include those having 2 to 6 carbon atoms such as a hexenyl group. When m is 2 or more, the ring formed by combining two members in R ₂ is specifically a 3- to 8-membered ring such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring. A ring can be exemplified. The substitution position of R ₂ is not particularly limited,
It may be linked to any of the carbon atoms constituting the cyclic skeleton.

Further, R ₁ and R ₂ may have a substituent on an appropriate carbon, and the substituent may be C1 to C1.
Specific examples include C4 alkoxy group, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, carboxy group, alkoxycarbonyl group and nitro group. . Further, the structure represented by the following formula can be exemplified as A.

[0016]

[Chemical 11]

Ra and Rb each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group or an alkoxy group, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, Preferable examples are lower alkyl groups such as n-butyl group.
Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group, and examples of the alkoxy group include C1-4C groups such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. it can.
Examples of the halogen atom include chlorine atom, bromine atom, fluorine atom, iodine atom and the like. r1 is 1 to 1
0 represents any integer, and r2 represents any integer of 1 to 3. Specific examples of the compound represented by the formula (I) are shown below.

[0018]

[Chemical 12]

[0019]

[Chemical 13]

[0020]

[Chemical 14]

[0021]

[Chemical 15]

[0022]

[Chemical 16]

Of these, the unit represented by I-101 is particularly preferable. In the present invention, the component (A) preferably further contains a repeating unit derived from a (meth) acrylic acid ester having an alicyclic hydrocarbon skeleton. As a repeating unit derived from a (meth) acrylic acid ester having an alicyclic hydrocarbon skeleton,
The repeating unit represented by the formula (II) can be preferably exemplified.

[0024]

[Chemical 17]

In the repeating unit represented by the formula (II), R ₃
Is a hydrogen atom or C1 which may have a substituent.
Represents a C5 alkyl group, A represents the same meaning as described above, C
Represents any of the substituents represented by formulas (II-1) to (II-6).

[0026]

[Chemical 18]

In the formulas (II-1) to (II-6), R ₁₁ represents a C1 to C5 alkyl group, and Z together with the carbon atom forms an alicyclic hydrocarbon group. And R _{12 to} R ₁₆ each independently represent a linear or branched C 1 to C 4 alkyl group or an alicyclic hydrocarbon group, provided that at least 1 of R _{12 to} R ₁₄ is represented. Or R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group,
_{17 to} R ₂₁ each independently represent a hydrogen atom, a linear or branched C 1 to C 4 alkyl group or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ is an alicyclic carbon group. Represents a hydrogen group, and either R ₁₉ or R ₂₁ is a linear or branched C
1 to C4 represents an alkyl group or an alicyclic hydrocarbon group, R
_{22 to} R ₂₅ each independently represent a hydrogen atom, a linear or branched C 1 to C 4 alkyl group, provided that at least one of R _{22 to} R ₂₅ represents an alicyclic hydrocarbon group.

Specific examples of R _{3 are the same} as those of R _1, and specific examples of R ₁₁ are the same as those of R ₁ in consideration of the difference in carbon number. it can.
The alkyl group for R _{12 to} R ₂₅ may be substituted or unsubstituted, and may be straight-chain or branched-chain C.
1 to C4 alkyl group, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. it can. R ₃ and R _{11 to} R ₂₅ may have a further substituent on a suitable carbon, and as the substituent, a C 1 to C ₄ alkoxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom) ), An acyl group, an acyloxy group, a cyano group, a hydroxyl group, a carboxy group,
Examples thereof include an alkoxycarbonyl group and a nitro group.

The alicyclic hydrocarbon group for R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic, specifically, C5 or more. Groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure, etc. can be mentioned, and C6 to C30 alicyclic hydrocarbon groups are preferable, and C7 to C25 alicyclic hydrocarbon groups are particularly preferable. These alicyclic hydrocarbon groups may have a substituent on a suitable carbon. An example of the structure of the alicyclic portion of the alicyclic hydrocarbon group is shown below.

[0030]

[Chemical 19]

Among the alicyclic hydrocarbon skeletons exemplified above, adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cyclo Preferable examples include heptyl group, cyclooctyl group, cyclodecanyl group, cyclododecanyl group, adamantyl group, decalin residue, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, A cyclododecanyl group can be illustrated more preferably.

Specific examples of the substituents on these alicyclic hydrocarbon groups include alkyl groups, substituted alkyl groups, cycloalkyl groups, alkenyl groups, acyl groups, halogen atoms, hydroxyl groups, alkoxy groups, carboxyl groups and alkoxycarbonyl. A group etc. can be illustrated. More specifically, the alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group, more preferably a methyl group, an ethyl group, a propyl group,
It is an isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. As the alkoxy group (including the alkoxy group of the alkoxycarbonyl group), a methoxy group, an ethoxy group,
Examples thereof include C1 to C4 groups such as a propoxy group and a butoxy group.

Examples of the cycloalkyl group include cyclopropyl group, cyclopentyl group, cyclohexyl group and the like. Examples of the alkenyl group include C2-C6 alkenyl groups, and specifically, vinyl group, 1-propenyl group, allyl group, 2-butenyl group, 2-pentenyl group, 3
A hexenyl group and the like. Examples of the acyl group include acetyl group, ethylcarbonyl group and n-propylcarbonyl group. Examples of the halogen atom include chlorine atom, bromine atom, iodine atom and fluorine atom.

Among the structures represented by the formulas (II-1) to (II-6), the formula (II-1) is preferable, and the repeating unit represented by the formula (III) is more preferable.

[0035]

[Chemical 20]

In the formula, R ₁ has the same meaning as described above, and R _1
30 represents an alkyl group which may have a substituent, R ₃₁
To R ₃₂ each independently represent a hydroxyl group, a halogen atom, a carboxyl group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, an alkoxycarbonyl group, or an acyl group, and p, q, and r are each independently 0 or Represents an integer of 1 to 3, and when p, q, or r is 2 or more, R ₃₁ and R ₃₂ may be the same or different. R ₃₀ alkyl group in formula (III), R _{31 to} R
The halogen atom, the alkyl group, the cycloalkyl group, the alkenyl group, the alkoxy group, the alkoxycarbonyl group, and the acyl group in ₃₂ are the same as the specific examples exemplified as the substituent of the alicyclic hydrocarbon group. You can
By containing the unit of the formula (III), the component (A) changes from alkali-insoluble to alkali-soluble due to the action of the acid generated from the component (B), and a positive resist pattern is obtained. Therefore, when the copolymer containing the formula (I) and the formula (III) is used as the component (A), a positive type composition is obtained. Expression (I
Specific examples of the repeating unit represented by I) (including formula (III)) are shown below.

[0037]

[Chemical 21]

[0038]

[Chemical formula 22]

[0039]

[Chemical formula 23]

[0040]

[Chemical formula 24]

Among these, especially II-101 and II-1
The units represented by 02, II-103, and II-104 are preferable. In the present invention, the component (A) (meth) acrylic acid copolymer may further contain other repeating units in addition to the repeating units represented by the formulas (I) and (II), Specific examples of the other repeating unit include the repeating unit represented by the following formula (IV).

[0042]

[Chemical 25]

(In the formula, R ₃₄ represents a hydrogen atom or a linear or branched C 1 to C 5 alkyl group which may have a substituent, and R _{35 to} R ₃₇ are each independently. It represents a hydrogen atom or a substituent which may have a C1~C5 alkoxy group, at least one may have a substituent C1~C5 alkoxy group of R ₃₅ ~R _37.) formula Specific examples of R ₃₄ in (IV) are the same as the specific examples of R ₁ . R ₃₅
Specific examples of R ₃₇ to R ₃₇ include methoxy group, ethoxy group, n
-Propoxy group, isopropoxy group, n-butoxy group,
t-butoxy group, methoxymethoxy group, ethoxymethoxy group, methoxymethoxy group, 2-methoxyethoxymethoxy group, bis (2-chloroethoxy) methoxy group, tetrahydropyranyloxy group, 4-methoxytetrahydropyranyloxy group, tetrahydrofuran Nyloxy group, triphenylmethoxy group, trimethylsilyloxy group, 2
-(Trimethylsilyl) ethoxymethoxy group, t-butyldimethylsilyloxy group, trimethylsilylmethoxy group, t-butoxy group, t-butoxycarbonyloxy group, t-butoxycarbonylmethoxy group, 1-t-butoxycarbonylethoxy group, 1- Examples thereof include a methyl-1-t-butoxycarbonylethoxy group and the like, and an alkoxy group capable of decomposing or leaving with an acid to generate a hydroxyl group without inhibiting anionic polymerization is particularly preferable. At least one of R _{35 to} R ₃₇ is an alkoxy group, preferably a dialkoxy body or a monoalkoxy body, and more preferably a monoalkoxy body. Also, the following formula

[0044]

[Chemical formula 26]

(In the formula, R₃₈Is C1-C20 with no substitution
Or alkoxy-substituted alkyl group, C5-C10
Or a C6 to C20 unsubstituted or aralkyl group
Represents a Coxy-substituted aryl group, R₃₉Is hydrogen or C1
~ Represents a C3 alkyl group, R ₄₀Is hydrogen, C1-C6
It represents an alkyl group or a C1-C6 alkoxy group. T
CD represents a tricyclodecanyl group. )
Examples of such substituents include
Is a 1-methoxyethyl group, a 1-ethoxyethyl group, 1
-Methoxypropyl group, 1-methyl-1-methoxyethyl
Group, 1- (isopropoxy) ethyl group, 1-ethoxy
An ethoxyethyl group etc. can be illustrated.

The acrylic acid copolymer as the component (A) may further contain repeating units corresponding to the following monomers. Methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, -t-octyl acrylate, chloroethyl acrylate, 2-ethoxyethyl acrylate,
Acrylic esters such as 2,2-dimethyl-3-ethoxypropyl acrylate, 5-ethoxypentyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl Methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate,
Octyl methacrylate, 2-ethoxyethyl methacrylate, 4-methoxybutyl methacrylate, 5-methoxypentyl methacrylate, 2,2-dimethyl-3-
Methacrylic acid esters such as ethoxypropyl methacrylate, furfuryl methacrylate, and tetrahydrofurfuryl methacrylate.

Methyl crotonate, ethyl crotonate, propyl crotonate, amyl crotonate, cyclohexyl crotonate, ethylhexyl crotonate, octyl crotonate, -t-octyl crotonate, chloroethyl crotonate, 2-ethoxyethyl crotonate, 2,2-
Dimethyl-3-ethoxypropyl crotonate, 5-ethoxypentyl crotonate, benzyl crotonate,
Crotonic acid esters such as methoxybenzyl crotonate, furfuryl crotonate, tetrahydrofurfuryl crotonate, dimethyl itaconate, diethyl itaconate, dipropyl itaconate, diamyl itaconate, dicyclohexyl itaconate, bis (ethylhexyl) itaconate, itacon Dioctyl acid, itaconic acid-di-t-
Octyl, bis (chloroethyl) itaconate, bis (2-ethoxyethyl) itaconate, bis (2,2-
Dimethyl-3-ethoxypropyl) itaconate, bis (5-ethoxypentyl) itaconate, dibenzylitaconate, bis (methoxybenzyl) itaconate,
Examples thereof include itaconic acid esters such as diflufurylitaconate and ditetrahydrofurfurylitaconate.

In the chemically amplified resist composition of the present invention, the component (A) (meth) acrylic acid copolymer is
It is preferably a copolymer containing a repeating unit represented by the formula (I), the formula (IX) or the formula (X).

[0049]

[Chemical 27]

(Wherein R ₁ has the same meaning as described above,
R ₃₀ ^'is a lower alkyl group. )

[0051]

[Chemical 28]

(In the formula, R ₁ has the same meaning as described above.)

[0053]

[Chemical 29]

(Wherein R ₁ has the same meaning as described above,
R ₁₀ represents an alkoxyalkyl group, an alkoxyalkoxyalkyl group or a tricyclodecanyl group. ) In the (meth) acrylic acid copolymer of the component (A), the ratio of each repeating unit can be arbitrarily selected by the ratio of the monomers used in the reaction, and is represented by, for example, the formula (I). The content of the repeating unit is preferably 30 to 70 mol%, more preferably 35 to 65 mol%, and further preferably 40 to 60 mol% in all repeating units. Also, the formula (I
I), particularly, the content of the repeating unit represented by the formula (III) is preferably 20 to 75 mol%, more preferably 25 to 70 mol%, further preferably 30 to 65 mol, based on all repeating units. %. The content of the repeating unit represented by the formula (IV) or (V) is usually 0 mol% to 70 mol% in all the monomer repeating units, preferably 5 to 40 mol%, more preferably 5 to 40 mol%. It is 20 mol%.

The total number of moles of the repeating unit represented by the formula (I) and the formula (II), particularly the repeating unit represented by the formula (III) is 99 mol% or less based on the total number of moles. Is preferable, more preferably 90 mol% or less, still more preferably 80 mol% or less. The number average molecular weight Mn of the acrylic acid copolymer produced by the present invention is a polystyrene standard by gel permeation chromatography, preferably 1,000 to 1,000,00, more preferably 1,500 to 500. 1,000, more preferably 2,000 to 200,000, particularly preferably 2.5.
The range is from 00 to 100,000. In addition, the component (A)
The acrylic acid copolymer has a molecular weight distribution of 1.01-1.
It is in the range of 50 and is preferably 1.01 to 1.30. Specific examples of the combination of repeating units of the acrylic acid copolymer produced by the method of the present invention are shown below.

[0056]

[Table 1]

[0057]

[Table 2]

The acrylic acid copolymer as the component (A) has, for example, an anionic polymerization initiator as a polymerization initiator, and an alkali metal salt of a mineral acid of 0.1 equivalent or more and less than 1.0 equivalent to the anionic polymerization initiator. And / or in the presence of an alkaline earth metal salt,
It can be prepared by copolymerizing two or more kinds of (meth) acrylic acid esters.

The component (B) is a compound which generates an acid upon irradiation with radiation. When the component (A) contains an acid dissociable, dissolution inhibiting group, it becomes a positive resist, which makes the component (A) insoluble in alkali. The component (B) generates an acid upon irradiation with radiation, and the component (A)
The dissolution inhibiting group therein is dissociated to change the component (A) itself into alkali-soluble. When the component (A) does not contain an acid dissociable, dissolution inhibiting group, a negative resist can be obtained by further adding a known crosslinking agent. Examples of such a cross-linking agent include amino-based cross-linking agents such as melamine, urea, glycoluril, and ethylene urea having an alkoxymethyl group or a hydroxy group. The component (B) is not particularly limited as long as it has such an action, but an onium salt such as an iodonium salt or a sulfonium salt is preferable, and a triphenylsulfonium salt having a substituted or unsubstituted benzene nucleus, The sulfonium salt represented by (VI) is particularly preferable. In the present invention, these may be used alone or in combination of two or more.

[0060]

[Chemical 30]

(Wherein Ar represents an aryl group and X ⁻ represents a fluoroalkyl sulfonate ion having 1 to 15 carbon atoms) The triphenylsulfonium salt having a substituted or unsubstituted benzene nucleus is, for example, a methyl group. , Lower alkyl groups such as ethyl group, propyl group, butyl group and tert-butyl group; lower alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, tert-butoxy group; halogen atoms such as fluorine and chlorine; The benzene nucleus may be substituted with a substituent such as or a triphenylsulfonium salt having no substituent. The anion is not particularly limited, but a fully or partially fluorinated alkyl sulfonate ion having 1 to 15 carbon atoms is preferable because of strong acid strength.

Specifically, triphenyl sulfonium trifluoromethane sulfonate, nonafluorobutane sulfonate, heptadecafluorooctyl sulfonate, camphor sulfonate and naphthalene sulfonate; tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, nonafluorobutane sulfonate , Heptadecafluorooctyl sulfonate,
Camphor sulfonate and naphthalene sulfonate; 4-methylphenylbis (4-ethoxyphenyl)
Sulfonium trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctylsulfonate, camphorsulfonate and naphthalenesulfonate; 4-methoxyphenylbis (4-
Examples include chlorophenyl) sulfonium trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctylsulfonate, camphorsulfonate and naphthalenesulfonate.

In the sulfonium salt represented by the formula (VI), examples of the aryl group include a substituted or unsubstituted phenyl group and a naphthyl group. Specific examples include those represented by the following structural formulas.

[0064]

[Chemical 31]

Examples of X ⁻ include trifluoromethane sulfonate, nonafluorobutane sulfonate, heptadecafluorooctyl sulfonate and the like. When the triphenylsulfonium salt having a substituted or unsubstituted benzene nucleus and the sulfonium salt represented by the formula (V) are mixed and used, the former is preferably mixed with 5 to 25% by mass. -20 mass% is especially preferable.

The component (B) is 1 to 2 relative to the component (A).
It is preferably used in a proportion of 0% by mass, and particularly preferably used in a proportion of 2 to 10% by mass.

Component (C) From the viewpoint of preventing excessive diffusion of acid from the exposed portion and stability of the resist pattern over time, it is preferable to add amines to the chemically amplified resist composition of the present invention. Examples of amines include secondary or tertiary alkanolamines such as diethanolamine, triethanolamine, tributanolamine, and triisopropanolamine, which are difficult to volatilize from the resist film by heating during prebaking, and diethylamine, triethylamine, dibutylamine. , Secondary or tertiary alkyl amines such as tributyl amine. The amount of the component (A) is 100
0.01 to 5 parts by weight is preferable with respect to parts by weight, and 0.1
-1 part by weight is particularly preferred.

The chemically amplified resist composition of the present invention comprises
As long as the object of the present invention is not impaired, compatible additives as necessary, for example, additional resins for improving the performance of the resist film, plasticizers, stabilizers, surfactants, developed images A colorant for making it more visible, a sensitizer for further improving the sensitizing effect, a dye for antihalation, a conventional additive such as an adhesion improver can be contained.

The chemically amplified resist composition of the present invention comprises
Component (A), component (B) and optionally component (C),
It can be prepared by dissolving other components in an organic solvent. Examples of the organic solvent used in the present invention include ketones such as acetone, methyl ethyl ketone, cyclohexanone, isobutyl methyl ketone, isoamyl methyl ketone, and 1,1,1-trimethylacetone;
Polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate or monoethylene ether of diethylene glycol monoacetate, monoethyl ether, monopropyl ether, monoisopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof; dioxane Such cyclic ethers; and esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, and ethyl 3-ethoxypropionate. These may be used alone or in combination of two or more.

A resist pattern can be formed using the chemically amplified resist composition of the present invention. For example,
First, the above chemically amplified resist composition is applied onto a silicon wafer or a glass square substrate using a spinner or the like to form a coating film. This is pre-baked on a hot plate or the like and dried, and then Kr is passed through a mask pattern.
Exposure to radiation such as F, ArF, F2, EVU laser, electron beam and X-ray. After heat-treating (PEB) this,
A resist pattern is formed by developing with an alkali developing solution such as TMAH (tetramethylammonium hydroxide), washing and drying.

[0071]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following examples.

Component (A) represented by the following formula (VII)

[0073]

[Chemical 32]

A-1 In the formula (VII), n = 50, m = 50, l = 0, R
'= Methyl group, and GPC analysis shows Mw = 600
0, a monodisperse polymer of Mw / Mn = 1.25 was A-1
Used as.

A-2 In the formula (VII), n = 50, m = 50, l = 0, R
'= Ethyl group, Mw = 600 by GPC analysis
0, Mw / Mn = 1.25 of monodisperse polymer as A-2
Used as.

A-3 In the formula (VII), n = 40, m = 50, l = 10,
R '= methyl, R = a _{-C 2 H 4 O-C 2} H 5, GP
A monodisperse polymer having Mw = 6000 and Mw / Mn = 1.25 by C analysis is used as A-3.

A-4 In the formula (VII), n = 40, m = 50, l = 10,
R ′ = methyl group, R = tricyclo [5.2.1.
0 ^2,6 ] decyl group

[0078]

[Chemical 33]

According to GPC analysis, Mw = 600
0, Mw / Mn = 1.25 of monodisperse polymer as A-4
Used as.

A-5 In the formula (VII), n = 40, m = 50, l = 10,
R '= methyl group, R = ethoxyethoxyethyl methacrylate, Mw = 6000, Mw / by GPC analysis
A monodisperse polymer with Mn = 1.25 is used as A-5.

A-6 In the formula (VII), n = 50, m = 50, l = 0, R
'= Methyl group, Mw = 600 by GPC analysis
0, Mw / Mn = 2.00 of monodisperse polymer as A-6
Used as.

A-7 In the formula (VII), n = 50, m = 50, l = 0, R
'= Ethyl group, Mw = 600 by GPC analysis
0, a monodisperse polymer of Mw / Mn = 2.00 was A-7
Used as.

A-8 In the formula (VII), n = 40, m = 50, l = 10,
R '= methyl, R = a _{-C 2 H 4 O-C 2} H 5, GP
A monodisperse polymer having Mw = 6000 and Mw / Mn = 2.00 by C analysis is used as A-8.

Examples 1 to 5 and Comparative Examples 1 to 3 Examples 1 to 5 are components (A) of A-1 to A-5, respectively.
Comparative Examples 1 to 3 used the components (A) of A-6 to A-8, respectively. 100 parts by mass of each component (A) obtained above, 2 parts by mass of triphenylsulfonium nonafluorobutanesulfonate (component (B)) and 0.2 part by mass of triethanolamine (component (C)) were added to propylene glycol monomethyl. Dissolved in 930 parts by mass of a mixture of ether acetate and γ-butyrolactone in a mass ratio of 90:10,
A chemically amplified resist composition was prepared. A positive plastic resist composition prepared on a silicon wafer having an organic antireflection film (manufactured by Shipley, trade name AR-19) having a thickness of 82 nm was spinner coated to a thickness of 350 nm, and then 90 ° C. at 140 ° C. Prebaking was performed for 2 seconds to obtain a resist coating film. Next, ArF scanner S30 through the mask
2 (NA0.60, σ0.75 manufactured by Nikon Corporation) was used for exposure, and then post exposure heat treatment (PEB) was performed at 130 ° C. for 90 seconds. Then, the exposed portion is removed by developing with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, rinsing with pure water for 30 seconds, and drying to remove a positive resist pattern on the substrate. Was formed.

When the resist pattern thus obtained was observed with a scanning electron microscope, Examples 1 to
In all the resists of No. 5, the 130 nm line and space pattern was formed with a good cross-sectional shape. Also,
The limiting resolution was 110 nm. Furthermore, footing did not occur at the interface between the substrate and the resist. There was no scum. Roughness is small, S-922
When 3σ, which is a scale for roughness, was measured by 0, 6 nm was good. The sensitivity is shown in Table 3 below. On the other hand, in all the resists of Comparative Examples 1 to 3, the 130 nm line and space pattern was formed with a good cross-sectional shape, but the limiting resolution was 120 nm.
Furthermore, footing occurred at the interface between the substrate and the resist. There was also scum. The roughness is big,
It was 9 nm when 3σ which is a scale for roughness was measured by S-9220. The sensitivity is as shown in Table 3.

[0086]

[Table 3]

[0087]

The component (A) used in the present invention is (meth)
It is a (meth) acrylic acid copolymer having an ester of acrylic acid and a specific monocyclohexane or bicycloheptanecarbolactone as a repeating unit, and has a very narrow molecular weight distribution. The chemically amplified resist composition of the present invention is obtained by using the (meth) acrylic acid copolymer as a resin, has excellent resolution, reduces line edge roughness, and has rectangular cross-section resist pattern. It is an excellent one.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ryotaro Hayashi             150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa East             Within Kyoka Kogyo Co., Ltd. F-term (reference) 2H025 AA02 AA03 AB16 AC04 AC08                       AD03 BE00 BE10 BG00 CB14                       CB41 CB55 CB56 FA17                 4J100 AL08P AL08Q AL08R BA04R                       BC12P BC52Q CA05 DA01                       DA04 JA38

Claims (8)

[Claims] 1. The following components (A) and (B) (A) the following formula (I): (In the formula, R ₁ represents a hydrogen atom or a C1 to C5 alkyl group which may have a substituent, and A represents a single bond, an alkyleneoxyalkylene group, a carbonyloxy group, an oxycarbonyl group, a carbonyl group. , An alkylene group, or a divalent group in which these are combined, B is represented by the formula (I-
1) to (I-4) [Chemical Formula 2] (In the formula, X represents an oxygen atom, a sulfur atom or an alkylene group which may have a substituent, and R ₂ represents an alkyl group which may have a substituent, a cycloalkyl group, or an alkenyl group. And m represents an integer of 0 or any of 1 to 5, and when m is 2 or more, R _{2 s} may be the same or different, and are bonded to each other to form a ring. May also be present). ), The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.01 to 1.
(Meth) acrylic acid copolymer having a range of 50, (B)
A chemically amplified resist composition obtained by dissolving a compound that generates an acid upon irradiation with radiation in an organic solvent. 2. The chemically amplified resist composition according to claim 1, wherein the component (A) further contains a repeating unit derived from a (meth) acrylic acid ester having an alicyclic hydrocarbon skeleton. 3. A repeating unit derived from a (meth) acrylic acid ester having an alicyclic hydrocarbon skeleton has the formula (II): (In the formula, R ₃ represents a hydrogen atom or a C1 to C5 alkyl group which may have a substituent, A represents the same meaning as described above, and C represents the formula (II-1) to ( II-6) [Chemical 4] (In the formula, R ₁₁ represents a C1-C5 alkyl group, and Z is
It represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom, and R _{12 to} R ₁₆ are each independently a linear or branched C 1 to C 4 alkyl group or an alicyclic hydrocarbon. Group, provided that at least one of R _{12 to} R ₁₄ or any one of R ₁₅ and R ₁₆ represents an alicyclic hydrocarbon group, and R _{17 to} R ₂₁ each independently represent a hydrogen atom or It represents a C1~C4 alkyl group or an alicyclic hydrocarbon group or branched chain, provided that at least one of R ₁₇ to R ₂₁ represents an alicyclic hydrocarbon group, one of R _19, R ₂₁ the R ₂₂ to R ₂₅ represents a straight-chain or C1 -C4 alkyl group branched or alicyclic hydrocarbon group, each independently represent a hydrogen atom, C1 -C4 straight or branched chain alkyl radical Provided that at least one of R _{22 to} R ₂₅ represents an alicyclic hydrocarbon group. ) Represents a substituent. The chemically amplified resist composition according to claim 2, wherein the chemically amplified resist composition is a repeating unit represented by the formula (1). 4. The repeating unit represented by the formula (II) has the formula (III): (In the formula, R ₁ represents the same meaning as described above, R ₃₀ represents an alkyl group which may have a substituent, and R _{31 to} R ₃₂ each independently represent a hydroxyl group, a halogen atom, a carboxyl group,
Represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, an alkoxycarbonyl group, or an acyl group, p, q, and r each independently represent an integer of 0 or 1 to 3, and p, q, or r is In the case of 2 or more, each R ₃₁ and R ₃₂ may be the same or different. The chemically amplified resist composition according to claim 3, which is a repeating unit represented by the formula (4). 5. The number average molecular weight of the (meth) acrylic acid copolymer of the component (A) is 1,000 to 1,000,000.
The chemically amplified resist composition according to any one of claims 1 to 4, which is in the range of. 6. The chemically amplified resist composition according to claim 1, wherein the (meth) acrylic acid copolymer as the component (A) is a random copolymer. 7. The (meth) acrylic acid copolymer of the component (A) is a copolymer containing a repeating unit represented by the following formula (VIII), formula (IX) or formula (X). Item 7. A chemically amplified resist composition according to item 5 or 6. [Chemical 6] (In the formula, R ₁ has the same meaning as described above, and R ₃₀ ^′ is a lower alkyl group.) (In the formula, R ₁ has the same meaning as described above.) (In the formula, R ₁ represents the same meaning as described above, R ₁₀ represents an alkoxyalkyl group, an alkoxyalkoxyalkyl group,
Represents a tricyclodecanyl group. ) 8. The chemistry according to claim 1, further comprising 0.01 to 5 parts by mass of amines as the component (C) with respect to 100 parts by mass of the component (A). Amplified resist composition.