JP2004004965A - Positive resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photoresist composition whose development defects are reduced in manufacturing of the positive photoresist composition and a pattern forming method using the same. <P>SOLUTION: The positive photoresist composition contains a resin which includes a specific repeating constitutional unit and whose dissolution rate in an alkaline developing solution is increased by the effect of an acid and a compound which generates the acid by irradiation with active rays or radiations and patterns are formed by using the positive photoresist composition. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a positive resist composition used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photofabrication processes. More specifically, the present invention relates to a positive photoresist composition with reduced development defects.

In recent years, the degree of integration of integrated circuits has increased further, and in the manufacture of semiconductor substrates such as VLSI, processing of ultra-fine patterns having a line width of less than half a micron has been required. In order to satisfy this need, the wavelength used by exposure apparatuses used in photolithography has become increasingly shorter, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. It is becoming.
A chemical amplification type resist is used for lithography pattern formation in this wavelength region.

Generally, chemically amplified resists can be broadly classified into three types, commonly called two-component systems, 2.5-component systems, and three-component systems. The two-component system combines a compound that generates an acid by photolysis (hereinafter referred to as a photoacid generator) and a binder resin. The binder resin is a resin having in its molecule a group (also referred to as an acid-decomposable group) that decomposes by the action of an acid and increases the solubility of the resin in an alkaline developer. The 2.5 component system further contains a low molecular weight compound having an acid-decomposable group in the two component system. A three-component system contains a photoacid generator, an alkali-soluble resin, and the low molecular weight compound.

The chemical amplification resist is suitable as a photoresist for irradiation with ultraviolet rays or far ultraviolet rays, but among them, it is necessary to cope with the required characteristics in use. As a photoresist composition for an ArF light source, there is a photoresist composition in which a (meth) acrylic resin that absorbs less light than a partially hydroxylated styrene resin is combined with a compound that generates an acid by light. Proposed.
For example, there are Patent Document 1 (Japanese Patent Laid-Open No. 7-199467), Patent Document 2 (Japanese Patent Laid-Open No. 7-252324), and the like. Among them, Patent Document 3 (Japanese Patent Application Laid-Open No. 6-289615) discloses a resin in which a tertiary carbon organic group is ester-bonded to oxygen of a carboxyl group of acrylic acid.

Further, Patent Document 4 (Japanese Patent Laid-Open No. 7-234511) discloses an acid-decomposable resin having an acrylic ester or fumaric acid ester as a repeating structural unit, but the pattern profile, substrate adhesion, etc. are insufficient. The fact is that satisfactory performance has not been obtained.

Furthermore, a resin having an alicyclic hydrocarbon moiety introduced for the purpose of imparting dry etching resistance has been proposed.
Patent Document 5 (Japanese Patent Laid-Open No. 9-73173), Patent Document 6 (Japanese Patent Laid-Open No. 9-90637), and Patent Document 7 (Japanese Patent Laid-Open No. 10-161313) are protected with a structure containing an alicyclic group. A resist material using an acid-sensitive compound containing an alkali-soluble group formed and an acid-sensitive compound containing a structural unit that can be eliminated by an acid to make the alkali-soluble group soluble is described.

Patent Document 6 (Japanese Patent Laid-Open No. 9-90637), Patent Document 8 (Japanese Patent Laid-Open No. 10-2007069), and Patent Document 9 (Japanese Patent Laid-Open No. 10-274852) disclose acid decomposition having a specific lactone structure. A resist composition containing a functional resin is described.

Lithographic processes that produce devices using 0.18 μm and 0.13 μm design rules often use light with a wavelength of 193 nm as exposure radiation, so resist polymers that do not contain much ethylenic unsaturation are desired. .
In Patent Document 10 (Japanese Patent Laid-Open No. 10-10739) and Patent Document 11 (Japanese Patent Laid-Open No. 10-307401), although transparency with respect to a wavelength of 193 nm is improved, it cannot necessarily be said to be highly sensitive, and 0.13 μm or later. In the case of the lithography, the resist performance is insufficient, such as insufficient resolution.
Patent Document 12 (Japanese Patent Laid-Open No. 10-130340) discloses a chemically amplified resist containing a terpolymer having a specific repeating structural unit having a norbornene structure in the main chain.
Patent Document 13 (Japanese Patent Laid-Open No. 11-305444) discloses a resin containing a repeating structural unit having an adamantane structure in the side chain and maleic anhydride as a repeating structural unit.
Patent Document 14 (Japanese Patent Laid-Open No. 11-109632) describes that a resin containing a polar group-containing alicyclic functional group and an acid-decomposable group is used for the radiation-sensitive material.
However, such a chemically amplified resist may cause defects during development and has room for improvement.

Japanese Unexamined Patent Publication No. 7-199467 JP 7-252324 A JP-A-6-289615 JP-A-7-234511 JP-A-9-73173 JP-A-9-90637 JP-A-10-161313 JP-A-10-207069 JP-A-10-274852 Japanese Patent Laid-Open No. 10-10739 JP-A-10-307401 JP-A-10-130340 JP-A-11-305444 JP-A-11-109632

Therefore, an object of the present invention is to provide a positive photoresist composition that can reduce the occurrence of development defects in the production of semiconductor devices.

As a result of intensive studies on the constituent materials of the positive chemical amplification resist composition, the present inventors have achieved the object of the present invention by using an acid-decomposable resin containing a repeating structural unit having a specific structure. As a result, the present invention has been achieved.
That is, the above object is achieved by the following configuration.
(1) (A) A repeating structural unit represented by the following general formula (I), a repeating structural unit represented by the following general formula (II-1), and a repeating structural unit represented by the following general formula (II-2) A positive photoresist composition comprising: a resin containing a resin that increases the dissolution rate in an alkaline developer by the action of an acid; and (B) a compound that generates an acid upon irradiation with an actinic ray or radiation.

In general formula (I), R < ₁₁ > -R < ₁₄ > represents the alkyl group which may have a hydrogen atom or a substituent each independently. a is 0 or 1;
In General Formula (II-1), R ₁ represents a hydrogen atom or a methyl group. A represents a single bond, an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group, or a combination of two or more groups selected from the group consisting of ester groups.
W represents at least one of partial structures containing alicyclic hydrocarbons represented by the following general formulas (pI) to (pVI).

In the formula, R ₁₅ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{16 to} R ₂₀ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{16 to} R ₁₈ , or Either R ₁₉ or R ₂₀ represents an alicyclic hydrocarbon group.
R _{21 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{21 to} R ₂₅ Represents an alicyclic hydrocarbon group. Further, either R ₂₃ or R ₂₅ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{26 to} R ₂₉ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{26 to} R ₂₉ is a fat Represents a cyclic hydrocarbon group.
In the general formula (II-2), R ₁ has the same meaning as R ₁ in the general formula (II-1). R _{2 to} R ₄ each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{2 to} R ₄ represents a hydroxyl group.

(2) The positive photoresist composition as described in (1) above, wherein the resin (A) further contains a repeating structural unit represented by the following general formula (III).

In formula (III):
Z ₂ represents —O— or —N (R ₃ ) —. Here, R ₃ represents a hydrogen atom, a hydroxyl group, or —OSO ₂ —R ₄ . R ₄ represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue.
(3) The positive photo according to (1) or (2) above, further comprising (D) an organic basic compound, (E) a fluorine-based and / or silicon-based surfactant. Resist composition.

The present invention can provide a positive photoresist composition that is effective in preventing development defects in the production of semiconductor devices.

Hereinafter, the components used in the present invention will be described in detail.
[1] (A) A resin whose rate of dissolution in an alkaline developer is increased by the action of an acid (hereinafter also referred to as “acid-decomposable resin”)
In the general formula (I) showing a repeating unit of the acid-decomposable resin, R ₁₁ to R ₁₄ represents an alkyl group which may have a hydrogen atom or a substituent.
The alkyl group for R _{11 to} R ₁₄ is preferably one having 1 to 12 carbon atoms, more preferably one having 1 to 10 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, an isopropyl group, n Preferred examples include -butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group. Examples of the substituent for the alkyl group include a hydroxy group, an alkoxy group, and an alkoxyalkoxy group. These alkoxy groups and alkoxyalkoxy groups preferably have 4 or less carbon atoms.
In general formula (I), a is 0 or 1.

In general formula (II-1) which shows the repeating structural unit of acid-decomposable resin, R < ₁ > represents a hydrogen atom or a methyl group.
In general formula (II-1), as an alkylene group of A, group represented by a following formula can be mentioned.
-[C (Rf) (Rg)] r-
In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and both may be the same or different. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r is an integer of 1-10.
In the general formula (II-1), examples of the cycloalkylene group of A include those having 3 to 10 carbon atoms, and examples thereof include a cyclopentylene group, a cyclohexylene group, and a cyclooctylene group.

W in general formula (II-1) represents at least 1 among the partial structures containing the alicyclic hydrocarbon represented by general formula (pI)-(pVI).
In general formulas (pI) to (pVI), the alkyl group in R _{16 to} R ₂₉ may be either substituted or unsubstituted, and is a linear or branched alkyl group having 1 to 4 carbon atoms. Represents. Examples of the alkyl group 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.
Further, the further substituent of the alkyl group includes an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

The alicyclic hydrocarbon group in R _{15 to} R _{29 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

In the present invention, preferred examples of the alicyclic moiety include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl. Group, cyclooctyl group, cyclodecanyl group and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Represent. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
Specific examples of the monomer corresponding to the repeating structural unit represented by formula (I) are shown below, but are not limited thereto.

Hereinafter, although the specific example of the monomer corresponding to the repeating structural unit shown by general formula (II-1) is shown, it is not limited to these.

In formula (II-2), R ₁ has the same meaning as R ₁ in the general formula (II-1). As described above, at least one of R _{2 to} R ₄ represents a hydroxyl group. The repeating structural unit represented by formula (II-2) is preferably a dihydroxy body or a monohydroxy body, more preferably a dihydroxy body.
The acid-decomposable resin (b) of the present invention can further contain a repeating unit represented by the general formula (III).

In the general formula (III), Z ₂ represents —O— or —N (R ₃ ) —. Here, R ₃ represents a hydrogen atom, a hydroxyl group, or —O—SO ₂ —R ₄ . R ₄ represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue.

The alkyl group for R ₄ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, still more preferably. Are a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.

Examples of the haloalkyl group in R ₄ include a trifluoromethyl group, a nanofluorobutyl group, a pentadecafluorooctyl group, and a trichloromethyl group.
Examples of the cycloalkyl group in R ₄ include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Hereinafter, specific examples of the monomer corresponding to the repeating structural unit represented by the general formula (III) are shown, but the invention is not limited thereto.

In addition to the above repeating structural units, the acid-decomposable resin as component (A) includes dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required characteristics of resist, resolving power and heat resistance. Various repeating structural units can be contained for the purpose of adjusting properties, sensitivity and the like.

Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
Thereby, the performance required for the acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

Specifically, the following monomers can be mentioned.
Acrylic acid esters (preferably alkyl acrylates having an alkyl group with 1 to 10 carbon atoms):
Methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, cyclohexyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxy Propyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, and the like.

Methacrylic acid esters (preferably alkyl methacrylate having 1 to 10 carbon atoms in the alkyl group):
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2 , 2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate and the like.

Acrylamides:
Acrylamide, N-alkylacrylamide (alkyl group having 1 to 10 carbon atoms, such as methyl group, ethyl group, propyl group, butyl group, t-butyl group, heptyl group, octyl group, cyclohexyl group, hydroxyethyl group, etc. N, N-dialkylacrylamide (alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, butyl, isobutyl, ethylhexyl, cyclohexyl, etc.), N-hydroxy Ethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like.

Methacrylamide:
Methacrylamide, N-alkylmethacrylamide (alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, cyclohexyl, etc.), N, N -Dialkylmethacrylamide (there are alkyl groups such as ethyl group, propyl group, butyl group), N-hydroxyethyl-N-methylmethacrylamide and the like.

Allyl compounds:
Allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyloxyethanol and the like.

Vinyl ethers:
Alkyl vinyl ethers (eg hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, Diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether and the like.

Vinyl esters:
Vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl acetoacetate, vinyl lactate, vinyl -Β-phenylbutyrate, vinylcyclohexylcarboxylate and the like.

Dialkyl itaconates:
Dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.
Dialkyl esters or monoalkyl esters of fumaric acid; dibutyl fumarate and the like.

Other crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile, maleilonitrile, etc.

In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

In the acid-decomposable resin, the molar ratio of each other repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and the general required performance of resist, resolving power and heat resistance. In order to adjust sensitivity and the like, it is set as appropriate.
The content of the repeating structural unit represented by the general formula (I) in the acid-decomposable resin is preferably from 25 to 70 mol%, more preferably from 28 to 65 mol%, still more preferably from 30 to 30 in all repeating structural units. 60 mol%.
In this invention, content of the repeating structural unit shown by general formula (II-1) in acid-decomposable resin is 5-40 mol% in all repeating structural units, More preferably, it is 10-35 mol%. More preferably, it is 15-30 mol%.
In this invention, content of the repeating structural unit shown by general formula (II-2) in acid-decomposable resin is 3-30 mol% in all repeating structural units, More preferably, it is 5-25 mol%. More preferably, it is 8 to 20 mol%.
In the acid-decomposable resin, the content of the repeating structural unit represented by the general formula (III) is preferably 20 to 80 mol%, more preferably 25 to 70 mol%, still more preferably 30 to 60 in all repeating structural units. Mol%.

Further, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can be appropriately set according to the performance of the desired resist. Generally, the general formula (I) , (II-1) and (II-2) are preferably 99 mol% or less, more preferably 90 mol% or less, still more preferably 80 mol% or less, based on the total number of moles of the repeating structural units represented by (II-2). is there.

The molecular weight of the acid-decomposable resin as described above is a weight average (Mw: polystyrene conversion value by GPC method), preferably 1,000 to 1,000,000, more preferably 1,500 to 500,000, Preferably, it is in the range of 2,000 to 200,000, more preferably 2,500 to 100,000, and the larger the value, the better the heat resistance and the like, while the developability and the like are lowered, and these are preferable due to the balance. Adjusted to range. The acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization).

In the positive photoresist composition of the present invention, the compounding amount of the acid-decomposable resin in the whole resist composition is preferably 40 to 99.99% by weight, more preferably 50 to 99.97% by weight in the total solid content. It is.

Hereinafter, preferred specific examples of combinations of repeating structural units of the acid-decomposable resin as the component (A) will be shown.

[2] (B) Compound that generates acid upon irradiation with actinic ray or radiation (photoacid generator)
The photoacid generator used in the present invention is a compound that generates an acid upon irradiation with actinic rays or radiation.
As the photoacid generator used in the present invention, it is used as a photoinitiator for photocationic polymerization, a photoinitiator for radical photopolymerization, a photodecolorant for dyes, a photochromic agent, a microresist, or the like. Acid by known light (400-200 nm ultraviolet light, far ultraviolet light, particularly preferably g-line, h-line, i-line, KrF excimer laser beam), ArF excimer laser beam, electron beam, X-ray, molecular beam or ion beam Can be selected and used as appropriate.

Examples of other photoacid generators used in the present invention include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, onium salts such as arsonium salts, organic halogen compounds, organic metals / organics. Examples include halides, photoacid generators having an o-nitrobenzyl-type protecting group, compounds that generate photosulfonic acid by photolysis, such as iminosulfonates, disulfone compounds, diazoketosulfones, diazodisulfone compounds, etc. Can do.
Moreover, the group which generate | occur | produced the acid by these light, or the compound which introduce | transduced the compound into the principal chain or side chain of the polymer can be used.

Furthermore, VNRPillai, Synthesis, (1), 1 (1980), A. Abad etal, Tetrahedron Lett., (47) 4555 (1971), DHR Barton etal, J. Chem. Soc., (C), 329 (1970) ), Compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

Among the above-mentioned compounds that generate an acid, those that are particularly effectively used will be described below.
(1) An oxazole derivative represented by the following general formula (PAG1) substituted with a trihalomethyl group or an S-triazine derivative represented by the general formula (PAG2).

In the formula, R ²⁰¹ represents a substituted or unsubstituted aryl group or alkenyl group, R ²⁰² represents a substituted or unsubstituted aryl group, alkenyl group, alkyl group, or —C (Y) ₃ . Y represents a chlorine atom or a bromine atom.
Specific examples include the following compounds, but are not limited thereto.

(2) An iodonium salt represented by the following general formula (PAG3) or a sulfonium salt represented by the general formula (PAG4).

Here, Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group.
R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represents a substituted or unsubstituted alkyl group or aryl group.

Z ⁻ represents a counter anion, for example, a perfluoroalkanesulfonic acid anion such as BF ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , penta Examples include, but are not limited to, condensed polynuclear aromatic sulfonate anions such as fluorobenzene sulfonate anion and naphthalene-1-sulfonate anion, anthraquinone sulfonate anion, and sulfonate group-containing dyes.

Two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded via a single bond or a substituent.

Specific examples include the following compounds, but are not limited thereto.

In the above, Ph represents a phenyl group.
The above onium salts represented by the general formulas (PAG3) and (PAG4) are known, and can be synthesized, for example, by the methods described in U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331. .

(3) A disulfone derivative represented by the following general formula (PAG5) or an iminosulfonate derivative represented by the general formula (PAG6).

In the formula, Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group or aryl group. A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group.
Specific examples include the following compounds, but are not limited thereto.

(4) A diazodisulfone derivative represented by the following general formula (PAG7).

Here, R represents a linear, branched or cyclic alkyl group, or an aryl group which may be substituted.
Specific examples include the following compounds, but are not limited thereto.

The amount of these photoacid generators added is usually in the range of 0.01 to 30% by weight, preferably 0.3 to 20% by weight, more preferably 0.8%, based on the solid content in the composition. It is used in the range of 5 to 10% by weight.
If the addition amount of the photoacid generator is less than 0.01% by weight, the sensitivity tends to be low, and if the addition amount is more than 30% by weight, the light absorption of the resist becomes too high, resulting in deterioration of the profile or process. (Especially bake) The margin becomes narrow, which is not preferable.

[3] (D) Organic Basic Compound A preferred (D) organic basic compound that can be used in the present invention is a compound that is more basic than phenol. Of these, nitrogen-containing basic compounds are preferred.
(D) By adding an organic basic compound, the sensitivity fluctuation with time is improved. (D) As an organic basic compound, the compound which has a structure shown below is mentioned.

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or carbon. A substituted or unsubstituted aryl group of formula 6 to 20, wherein R ²⁵¹ and R ²⁵² may be bonded to each other to form a ring.

(Wherein R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represents an alkyl group having 1 to 6 carbon atoms)
Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group. Preferred examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, substituted or unsubstituted Pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted amino Examples include morpholine and substituted or unsubstituted aminoalkylmorpholine. Preferred substituents are amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group It is.

Preferable specific examples of the nitrogen-containing basic compound include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2- Dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4- Amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2 Iminopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5 Methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, 1,5-diazabicyclo [ 4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] octane, 2,4,5- Triphenylimidazole, N-methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, N-benzylmorpholine, cyclohexane Examples include tertiary morpholine derivatives such as silmorpholinoethylthiourea (CHMETU), hindered amines described in JP-A No. 11-52575 (for example, those described in the publication [0005]), and the like. Absent.

Particularly preferred examples are 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2. 2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, tertiary morpholines such as CHMETU, bis (1, And hindered amines such as 2,2,6,6-pentamethyl-4-piperidyl) sebagate.
Among them, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, CHMETU, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate are preferred.

These organic basic compounds are used alone or in combination of two or more. The usage-amount of an organic basic compound is 0.001-10 weight% normally with respect to solid content of the whole composition of the photosensitive resin composition, Preferably it is 0.01-5 weight%. If it is less than 0.001% by weight, the effect of adding the organic basic compound cannot be obtained.
On the other hand, when it exceeds 10% by weight, there is a tendency for the sensitivity to deteriorate and the developability of the non-exposed area to deteriorate.

[4] (E) Fluorine-based and / or silicon-based surfactant The positive photoresist composition of the present invention preferably contains a fluorine-based and / or silicon-based surfactant.
The positive photoresist composition of the present invention may contain any one or two or more of fluorine-based surfactants, silicon-based surfactants, and surfactants containing both fluorine atoms and silicon atoms. preferable.
When the positive photoresist composition of the present invention contains the acid-decomposable resin and the surfactant, the density dependency is improved.

As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540, JP-A-63-34540 7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, U.S. Patents 5405720, 5360692, 5529881, 5296330, 5436098, 5576143 No. 5945511 and No. 5842451, and the following commercially available surfactants can be used as they are.
Commercially available surfactants that can be used include, for example, F-top EF301, EF303 (made by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (made by Sumitomo 3M Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. A surfactant or a silicon-based surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon surfactant.

The compounding amount of the surfactant is usually 0.001% to 2% by weight, preferably 0.01% to 1% by weight, based on the solid content in the composition of the present invention. These surfactants may be added alone or in several combinations.
As surfactants that can be used in addition to the above, specifically, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, etc. , Polyoxyethylene alkyl allyl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan Sorbitan fatty acid esters such as monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene sorbitan Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as laurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Etc. can be mentioned.
The amount of these other surfactants is usually 2 parts by weight or less, preferably 1 part by weight or less per 100 parts by weight of the solid content in the composition of the present invention.

The positive photoresist composition of the present invention comprises, as a coating solvent, propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, alkyl lactates such as methyl lactate and ethyl lactate, propylene glycol Propylene glycol monoalkyl ethers such as monomethyl ether and propylene glycol monoethyl ether, ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, etc. Ethylene glycol monoalkyl ether acetates, 2-hepta , Γ-ptyrolactone, alkyl alkoxypropionates such as methyl methoxypropionate and ethyl ethoxypropionate, alkyl pyruvates such as methyl pyruvate and ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylacetamide, The coating is performed using at least one solvent selected from dimethyl sulfoxide and the like.

Preferably, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl lactate, and ethyl lactate are used. These solvents can be used alone or in combination, but since the number of development defects is reduced, one or more solvents are selected and mixed from propylene glycol monoalkyl ether acetates and lactic acid alkyl esters. Is particularly preferred. Here, the mixing ratio is preferably 95/5 to 30/70 by weight.
In the present invention, the solid content of the resist composition containing each of the above components is preferably dissolved in the solvent in a solid content concentration of 3 to 25% by weight, more preferably 5 to 22% by weight, and even more preferably 7%. -20% by weight.

If necessary, the positive photoresist composition of the present invention may further contain an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a compound that promotes solubility in a developer, and the like. it can.

Such a positive photoresist composition of the present invention is applied onto a substrate to form a thin film. The thickness of this coating film is preferably 0.2 to 1.2 μm. In the present invention, a commercially available inorganic or organic antireflection film can be used if necessary.

As the antireflection film, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, α-silicon, and an organic film type made of a light absorber and a polymer material can be used. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin-type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone-based light absorber described in JP-A-8-87115, and a low-molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.
Further, as the organic antireflection film, DUV30 series, DUV-40 series manufactured by Brewer Science, AC-2, AC-3 manufactured by Shipley, etc. can be used.

Appropriate use of the resist solution on a substrate (eg, silicon / silicon dioxide coating) used for the manufacture of precision integrated circuit elements (on a substrate provided with the antireflection film if necessary), spinner, coater, etc. A good resist pattern can be obtained by applying through a predetermined coating method, exposing through a predetermined mask, baking and developing. Here, the exposure light is preferably light having a wavelength of 150 nm to 250 nm. Specific examples include a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), an F ₂ excimer laser (157 nm), an X-ray, and an electron beam.

Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, and di-n. -Secondary amines such as butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. An alkaline aqueous solution of cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

(1) Synthesis of Resin (1) Norbornene, 2-methyl-2-adamantyl acrylate, maleic anhydride, and 3,5-dihydroxyadamantyl acrylate are charged into a reaction vessel at a molar ratio of 30/30/30/10 to give methyl ethyl ketone. Dissolved to prepare a 60% solids solution. This was heated at 60 ° C. under a nitrogen stream. When the reaction temperature was stabilized, 1.5 mol% of a radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to initiate the reaction. After heating for 10 hours, the reaction mixture was diluted 2-fold with methyl ethyl ketone, and then added to a 5-fold amount of tert-butyl methyl ether / hexane = 1/1 mixed solvent to precipitate a white powder. The precipitated powder is dissolved again in methyl ethyl ketone and added to a 5-fold amount of tert-butyl methyl ether / hexane = 1/1 mixed solvent to precipitate a white powder, filtered out, dried, and dried as a target resin (1 )
When the molecular weight analysis by GPC of the obtained resin (1) was tried, it was 13700 (weight average) in terms of polystyrene. From the NMR spectrum, the composition of the resin (1) was norbornene / 2-methyl-2-adamantyl acrylate / maleic anhydride / 3,5-dihydroxyadamantyl acrylate of the present invention at a molar ratio of 24/31/38/7. It was.
Resins (2) to (7) were synthesized in the same manner.
The repeating structural units constituting these resins are shown as specific examples (1) to (7) of the aforementioned resins.

Examples 1-16 and comparative examples
(Preparation and evaluation of positive photoresist composition)
2 g of each of the resins synthesized in the above synthesis examples (shown in Table 2 below) and a photoacid generator, 5 mg of an organic basic compound, and 5 mg of a surfactant shown in Table 2 are blended, and each has a solid content of 10% by weight. Were dissolved in the solvents shown in Table 2 and filtered through a 0.1 μm microfilter to prepare positive resist compositions of Examples 1 to 16.
Further, as Comparative Example 1, the resin (R) shown in Table 2 (resin A4 obtained in Synthesis Example 11 of JP-A-11-305444), a photoacid generator (PAG-R: 4-methylphenyl) A positive resist composition was prepared in the same manner as in Example 1 except that diphenylsulfonium trifluoromethanesulfonate) and a solvent were used.

As a solvent,
S1: propylene glycol monomethyl ether acetate S2: propylene glycol monomethyl ether propionate S3: ethyl lactate S4: butyl acetate S5: 2-heptanone S6: propylene glycol monomethyl ether S7: ethoxyethyl propionate S8: γ-butyrolactone S9: ethylene Carbonate S10: Propylene carbonate

As surfactant,
W-1: Megafuck F176 (Dainippon Ink Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Co., Ltd.) (fluorine and silicone)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
W-4: Polyoxyethylene nonylphenyl ether W-5: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

As an organic basic compound,
1: DBU (1,8-diazabicyclo [5.4.0] -7-undecene)
2: 4-DMAP (4-dimethylaminopyridine)
3: TPI (2,4,5-triphenylimidazole)
4: 2,6-diisopropylaniline

(Evaluation test)
[Development defects]: Each resist film was applied to a thickness of 0.3 μm on a 6-inch Bare Si substrate, and dried on a vacuum adsorption hot plate at 135 ° C. for 60 seconds. Next, after exposure using an ArF excimer laser stepper (ArF exposure machine 9300 manufactured by ISI) through a test mask having a 0.16 μm contact hole pattern (Hole Duty ratio = 1: 3), post-exposure heating is performed at 160 ° C. at 90 ° C. For a second. Subsequently, the paddle development was performed with 2.38% TMAH (tetramethylammonium hydroxide aqueous solution) for 60 seconds, followed by washing with pure water for 30 seconds and spin drying. The number of development defects was measured using a KLA-2112 machine manufactured by KLA-Tencor Co., Ltd., and the obtained primary data value was defined as the number of development defects.
These evaluation results are shown in Table 3.

As shown in Table 3 above, the positive photoresist composition of the present invention showed excellent performance in reducing development defects.

Claims (4)

(A) a repeating structural unit represented by the following general formula (I), a repeating structural unit represented by the following general formula (II-1), and a repeating structural unit represented by the following general formula (II-2), It contains a resin whose dissolution rate in an alkaline developer is increased by the action of an acid, (B) a compound that generates an acid upon irradiation with actinic rays or radiation, and (E) a fluorine-based and / or silicon-based surfactant. A positive photoresist composition.

In general formula (I), R _{11 to} R ₁₄ each independently represents a hydrogen atom, an unsubstituted alkyl group, or an alkyl group substituted with a hydroxy group, an alkoxy group, or an alkoxyalkoxy group. a is 0 or 1;
In General Formula (II-1), R ₁ represents a hydrogen atom or a methyl group. A represents a single bond, an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group, or a group of two or more groups selected from the group consisting of ester groups.
W represents at least one of partial structures containing alicyclic hydrocarbons represented by the following general formulas (pI) to (pVI).

In the formula, R ₁₅ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R ₁₆ to R ₂₀ each independently of 1 to 4 carbon atoms, represents a linear or branched alkyl group or alicyclic hydrocarbon group, provided that at least one of R ₁₆ to R _18, or Either R ₁₉ or R ₂₀ represents an alicyclic hydrocarbon group.
R _{21 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{21 to} R ₂₅ Represents an alicyclic hydrocarbon group. Further, either R ₂₃ or R ₂₅ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{26 to} R ₂₉ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{26 to} R ₂₉ is a fatty acid. Represents a cyclic hydrocarbon group.
In the general formula (II-2), R ₁ has the same meaning as R ₁ in the general formula (II-1). R _{2 to} R ₄ each independently represent a hydrogen atom or a hydroxyl group. However, one of R _{2 to} R ₄ is a hydroxyl group. 2. The positive photoresist composition according to claim 1, wherein R _{11 to} R ₁₄ in formula (I) each independently represent a hydrogen atom or an unsubstituted alkyl group. The positive photoresist composition according to claim 1 or 2, wherein the content of the repeating unit represented by the general formula (II-1) is 15 to 30 mol% in all repeating structural units. . A pattern forming method comprising: forming a resist film from the positive photoresist composition according to claim 1; and exposing and developing the resist film.