JP2005099275A - Positive resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition which can satisfy resolution, sensitivity, thermal flow rate control, reduction of the initial number of particles and reduction of the increase of the number of the particles during storage simultaneously and to provide a pattern forming method using the composition. <P>SOLUTION: The positive resist composition contains: (A) a resin which has a specified recurring unit and is increased in the solubility to an alkali developer by the action of an acid; (B) a compound which produces the acid by the irradiation of an active ray or a radioactive ray; (C) a specified compound; and (D) a solvent. The pattern forming method uses the positive resist composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a positive resist composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication processes, and a pattern forming method using the same. . More specifically, the present invention relates to a positive resist composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less and an irradiation source using an electron beam, and a pattern forming method using the same.

  The chemically amplified positive resist composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and dissolves in the developing solution of the active radiation irradiated area and the non-irradiated area by a reaction using this acid as a catalyst. It is a pattern forming material that changes the properties and forms the pattern on the substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

  On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.

  For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed.

  Patent Document 1 (JP 2002-139840 A) and Patent Document 2 (US 2002/0048723 A1) describe a resist composition containing a polymer, a photoacid generator, a crosslinking agent, and an organic solvent. Is described.

  However, the conventional resist composition does not satisfy simultaneously the resolution, sensitivity, thermal flow rate control, reduction of the initial particle value, and reduction of the number of particles increased during storage over time.

JP 2002-139840 A US 2002/0048723 A1

  Accordingly, an object of the present invention is to provide a positive resist composition that simultaneously satisfies the resolution, sensitivity, thermal flow rate control, reduction of the initial particle value, and reduction of the increase in the number of particles during storage over time, and a pattern forming method using the same. It is to provide.

  The present invention has the following configuration, whereby the above object of the present invention is achieved.

(1) (A) a resin having the following four types of repeating units (A-1) to (A-4), the solubility of which is increased in an alkaline developer by the action of an acid;
(A-1) At least one repeating unit selected from repeating units represented by the following general formula (I):
(A-2) at least one type of repeating unit selected from repeating units having groups represented by the following general formulas (II-1) to (II-4);
(A-3) at least one repeating unit selected from repeating units represented by the following general formula (III) and (A-4) 2-alkyl-2-adamantyl group or 1-adamantyl-1-alkylalkyl group At least one repeating unit selected from repeating units having:
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) at least one compound selected from the following three types of compounds (C1) to (C3) and (C1) a compound represented by the following general formulas (VI-1) to (VI-3),
(C2) a compound represented by the following general formula (Za) or (Zb) and (C3) an epoxy compound,
(D) A positive resist composition containing a solvent.

In general formula (I), R _1a represents a hydrogen atom or a methyl group. W ₁ represents a single bond or a divalent linking group.

In general formulas (II-1) to (II-4), R _{1b to} R _5b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. Two of R _{1b to} R _5b may combine to form a ring.

In general formula (III), R _1c represents a hydrogen atom or a methyl group. R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.

In general formulas (VI-1) to (VI-3), R _1cc each independently represents a hydrogen atom, an alkyl group, or an acyl group. R _{2 cc} to R _{5 cc} each independently represents a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group. Xa represents a single bond, a methylene group or an oxygen atom.

In general formulas (Za) to (Zb), R ^{1aa to} R ^4aa each independently represent a hydrogen atom, an alkyl group, or a cycloalkyl group. R ^1aa and R ^3aa , R ^2aa and R ^3aa may be bonded to each other to form a ring. R ^{1bb to} R ^3bb each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ^1bb and R ^3bb , R ^2bb and R ^3bb may combine with each other to form a ring. X represents a k-valent organic group. k represents an integer of 2 to 6.

  (2) The positive resist composition as described in (1) above, which contains a triarylsulfonium salt as a compound that generates acid upon irradiation with actinic rays or radiation.

  (3) The positive resist composition as described in (1) or (2), further comprising (E) a nitrogen-containing basic compound.

  (4) The positive resist composition as described in any one of (1) to (3), wherein the glass transition temperature of the resin as the component (A) is 70 to 150 ° C.

  (5) The positive resist composition as described in any one of (1) to (4), which is for thermal flow.

  (6) The repeating unit (A-4) is a repeating unit having a 2-alkyl-2-adamantyl group, and the repeating unit (A-3) is a repeating unit having a dihydroxyadamantyl group. The positive resist composition for thermal flow as described in (5), which is characterized in that

  (7) A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of (1) to (6); and exposing and developing the resist film.

  According to the present invention, it is possible to provide a positive resist composition that simultaneously satisfies the resolving power, sensitivity, thermal flow rate control, particle initial value reduction, and reduction in the number of particles increased during storage over time, and a pattern forming method using the same. it can.

  Hereinafter, the present invention will be described in detail.

  In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

[1] (A) Resin having four types of repeating units represented by the general formulas (A-1) to (A-4) and having increased solubility in an alkaline developer by the action of an acid. The resist composition is a resin (hereinafter referred to as “acid decomposition”) having the four types of repeating units represented by the general formulas (A-1) to (A-4) and having increased solubility in an alkaline developer by the action of an acid. (Also referred to as a functional resin (A)).

  The acid-decomposable resin (A) has a repeating unit having a 2-alkyl-2-adamantyl group or a 1-adamantyl-1-alkylalkyl group.

  The acid-decomposable resin (A) is a 2-alkyl-2-adamantyl group represented by the following general formula (pI) or 1-adamantyl-1 represented by the following general formula (pII) in the acid-decomposable group. -It is preferable to have a repeating unit having an alkylalkyl group.

In the formula, R ₁₁ represents a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group or sec-butyl group, and Z is necessary for forming an adamantyl group together with the carbon atom. Represents an atomic group.

R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an adamantyl group, provided that at least one of R _{12 to} R ₁₄ , or R ₁₅ , R Any of ₁₆ represents an adamantyl group.

In the general formulas (pI) to (pII), the alkyl group in R _{12 to} R ₁₄ may be 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.

  Examples of the substituent for the adamantyl group include an 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, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl 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 further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pII) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.

  As the alkali-soluble group (acid-decomposable group) protected by the structure represented by the general formulas (pI) to (pII) in the above resin, groups represented by the following general formulas (pVII) to (pVIII) are preferable. Can be mentioned.

Here, R _{11 to} R ₂₅ and Z are the same as defined above.

  In the resin, the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pII) is preferably a repeating unit represented by the following general formula (pA).

  Here, R represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.

  A is a single bond, a group selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents.

  Ra represents any group of the above formulas (pI) to (pII).

  Specific examples of the monomer corresponding to the repeating unit represented by the general formula (pA) are shown below.

  The acid-decomposable resin (A) may have an acid-decomposable group as a partial structure containing an adamantyl group represented by the general formula (pI) to the general formula (pII), or a repeating copolymer component described later. You may have in at least 1 sort (s) of repeating units among units.

As the structure of the acid-decomposable group, in addition to the alkali-soluble group (acid-decomposable group) protected by the structure represented by the general formulas (pI) to (pII) described above, for example, —C (═O) — it can be exemplified those represented by X ₁ -R _0.

In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.

  The acid-decomposable resin (A) further has a repeating unit represented by the following general formula (I).

In general formula (I), R _1a represents a hydrogen atom or a methyl group. W ₁ represents a single bond or a divalent linking group.

Examples of the divalent linking group for W ₁ include a single group selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, and an ester group, or a combination of two or more of these groups. Can do.

In general formula (I), examples of the alkylene group for W ₁ include groups represented by the following formulae.

− [C (Rf) (Rg)] r ₁ −
In the above formula, Rf and Rg represent a hydrogen atom, an 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 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 further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r ₁ is an integer of 1 to 10.

  Hereinafter, although the specific example of the repeating unit shown by general formula (I) is shown, it is not limited to these.

  The acid-decomposable resin (A) further has a repeating unit having groups represented by the following general formulas (II-1) to (II-4).

In general formulas (II-1) to (II-4),
R _{1b to} R _5b each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. Two of R _{1b to} R _5b may combine to form a ring.

In the general formulas (II-1) to (II-4), the alkyl group, cycloalkyl group, or alkenyl group as R _{1b to} R _5b includes those each having a substituent.

Examples of the alkyl group in R _{1b to} R _5b include linear and branched alkyl groups, including those having a substituent. The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. More preferably, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl It is a group.

As a cycloalkyl group in R _<1b > -R < _5b >, C3-C8 things, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, are preferable.

As an alkenyl group in R _<1b > -R < _5b >, C2-C6 things, such as a vinyl group, a propenyl group, a butenyl group, a hexenyl group, are preferable.

Examples of the ring formed by combining two of R _{1b to} R _5b include 3- to 8-membered rings such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring.

In the general formulas (II-1) to (II-4), R _{1b to} R _5b may be connected to any carbon atom constituting the cyclic skeleton.

  Moreover, as a preferable substituent which the said alkyl group, a cycloalkyl group, and an alkenyl group may have, a C1-C4 alkoxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), Examples thereof include an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, and a nitro group.

  Examples of the repeating unit having a group represented by general formulas (II-1) to (II-4) include a repeating unit represented by the following general formula (AI).

In general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. As a preferable substituent which the alkyl group of R _b0 may have, as a preferable substituent which the alkyl group as R _1b in the general formulas (II-1) to (II-4) may have. What was illustrated previously is mentioned.

Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom.

  A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.

B ₂ represents a group represented by any one of the general formulas (II-1) to (II-4). In A ′, examples of the combined divalent group include those represented by the following formulae.

In the above formula, R _ab and R _bb represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, and 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, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl 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 further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r1 represents an integer of 1 to 10, preferably an integer of 1 to 4. m represents an integer of 1 to 3, preferably 1 or 2.

  Although the specific example of the repeating unit represented by general formula (AI) is given to the following, the content of this invention is not limited to these.

  The acid-decomposable resin (A) further has a repeating unit represented by the following general formula (III).

In general formula (III):
R _1c represents a hydrogen atom or a methyl group.

R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.

Two of R _{2c to} R _4c are preferably hydroxyl groups.

  Although the specific example of the repeating unit represented by general formula (III) below is given, it is not limited to these.

  The acid-decomposable resin (A) can further contain a repeating unit represented by the following general formula (VII).

In the general formula (VII), A ₆ 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.

R _6a represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen atom.

In the general formula (VII), examples of the alkylene group represented by A ₆ include groups represented by the following formulae.

-[C (Rnf) (Rng)] r-
In the above formula, Rnf and Rng represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, and 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 a methyl group, an ethyl group, a propyl group, or an isopropyl 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 further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy 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 (VII), examples of the cycloalkylene group represented by A ₆ include those having 3 to 10 carbon atoms, such as a cyclopentylene group, a cyclohexylene group, and a cyclooctylene group.

The bridged alicyclic ring containing Z ₆ may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), an alkoxycarbonyl group (preferably having 1 to 5 carbon atoms), an acyl group (for example, a formyl group and a benzoyl group), an acyloxy group ( For example, propyl carbonyloxy group, benzoyloxy group), an alkyl group (preferably having from 1 to 4 carbon atoms), a carboxyl group, a hydroxyl group and an alkylsulfonylsulfamoyl group (-CONHSO ₂ CH _3, etc.). In addition, the alkyl group as a substituent may be further substituted with a hydroxyl group, a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), or the like.

In general formula (VII), the oxygen atom of the ester group bonded to A ₆ may be bonded at any position of the carbon atom constituting the bridged alicyclic ring structure containing Z ₆ .

  Although the specific example of the repeating unit represented by general formula (VII) below is given, it is not limited to these.

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

  Examples of such a repeating unit include, but are not limited to, repeating units corresponding to the following monomers.

Thereby, the performance required for the resin (A), 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.

  Others include crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleilonitrile and the like.

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

  In the acid-decomposable resin (A), the content molar ratio of each repeating unit is the resist dry etching resistance, the standard developer suitability, the substrate adhesion, the resist profile, and the resolving power and heat resistance which are general required performance of the resist. In order to adjust the sensitivity and the like, it is set as appropriate.

  The acid-decomposable resin (A) is preferably a resin having a repeating unit of at least one acrylate derivative.

  The acid-decomposable resin (A) may contain a repeating unit derived from a methacrylic acid ester derivative in addition to the repeating unit derived from at least one kind of acrylic acid ester derivative. In the present invention, the repeating unit derived from the acrylate derivative also includes a repeating unit derived from acrylic acid itself.

  The repeating unit derived from the acrylate derivative contained in the acid-decomposable resin (A) may be any repeating unit constituting the acid-decomposable resin (A), and is represented by the general formula (pA). Unit, repeating unit represented by formula (I), repeating unit having groups represented by formulas (II-1) to (II-4), repeating unit represented by formula (III), acrylic It may be a repeating unit of an acid ester.

  As for content of the repeating unit which has an acid-decomposable group, 20-60 mol% is preferable with respect to all the repeating units, More preferably, it is 25-55 mol%, More preferably, it is 30-50 mol%.

  The content of the repeating unit having a partial structure containing an adamantyl group represented by the general formulas (pI) to (pII) is preferably 30 to 70 mol%, more preferably 35 to 65 mol based on all repeating units. %, More preferably 40 to 60 mol%.

  The content of the repeating unit represented by formula (I) is preferably 20 to 70 mol%, more preferably 25 to 60 mol%, based on all repeating units.

  The content of the repeating unit having a group represented by formulas (II-1) to (II-4) is preferably 20 to 70 mol%, more preferably 25 to 60 mol%, based on all repeating units. .

  The content of the repeating unit represented by the general formula (III) is preferably from 5 to 50 mol%, more preferably from 10 to 40 mol%, still more preferably from 15 to 35 mol%, based on all repeating units. .

  The content of the repeating unit derived from the acrylate ester is usually preferably from 10 to 90 mol%, from 20 to 90 mol%, more preferably from 40 to 80 mol%, still more preferably from 50 to 75, based on all repeating units. Mol%.

  When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The acid-decomposable resin (A) used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and if necessary, a reaction solvent such as ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, methyl ethyl ketone, A ketone such as methyl isobutyl ketone, an ester solvent such as ethyl acetate, and the composition of the present invention such as propylene glycol monomethyl ether acetate described below are dissolved in a solvent that dissolves uniformly and then nitrogen, argon, etc. Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an inert gas atmosphere. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery.

  The concentration of the reaction is usually 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 50 to 100 ° C.

  The repeating structural units represented by the above specific examples may be used singly or in combination.

  In the present invention, the resins may be used alone or in combination.

  The weight average molecular weight of the acid-decomposable resin (A) according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, as a polystyrene-converted value by the GPC method. The weight average molecular weight is preferably 1,000 or more from the viewpoint of the heat resistance and dry etching resistance of the resist film, and the weight average molecular weight is preferably 200,000 or less from the viewpoint of developability, viscosity, and film forming property. .

  The dispersity (Mw / Mn) is usually 1 to 10, preferably 1 to 5, more preferably 1 to 4. The smaller the degree of dispersion, the smoother the resolution, resist shape, and resist pattern side walls, and the better the roughness.

  The acid-decomposable resin (A) used in the present invention contains the specific repeating unit, and has a glass transition temperature of 70 to 150 ° C, preferably 80 to 140 ° C, more preferably 100 to 130 ° C.

  The glass transition temperature (Tg) can be measured by differential scanning calorimeter.

  In order to obtain a resin containing the above repeating unit and having a glass transition temperature of 70 to 150 ° C., for example, there are the following methods.

  In order to control the glass transition point within the specific range, it is necessary to control not only the repeating unit having the specific alicyclic structure but also the molecular weight and dispersity (Mw / Mn).

  The weight average molecular weight of the acid-decomposable resin (A) is usually 3000 to 30000, preferably 3000 to 20000, and more preferably 3000 to 10,000.

  The degree of dispersion of the acid-decomposable resin (A) is usually 3.5 or less, preferably 3.0 or less, more preferably 2.5 or less.

  In order to control the weight average molecular weight and the degree of dispersion, not only the above reaction conditions are selected, but the reaction monomer solution and the radical polymerization initiator solution are dropped into a solvent or the like heated to a constant temperature, or dropped dropwise. A polymerization method is desirable.

  Further, by removing the lower molecular weight side of the resin obtained by polymerization by the fractional reprecipitation method, the effect of the present invention can be further enhanced. The fractional reprecipitation method, for example, removes low molecular weight oligomers with high solvent solubility by pouring the resin solution into the poor solvent of the resin or pouring the poor solvent of the resin into the resin solution. Is the method.

  Examples of the poor solvent for the resin (A) include hydrocarbon solvents such as n-hexane, n-heptane, and toluene, mixed solvents of hydrocarbon solvents and ester solvents such as ethyl acetate, alcohols such as distilled water, methanol, and ethanol. These may be used alone or as a mixed solvent.

  On the other hand, the above-mentioned reaction solvent and the like can be used as a solvent for dissolving the resin. Here, the low molecular weight oligomer is, for example, one having a weight average molecular weight of 4000 or less.

  In the positive resist composition of the present invention, the blending amount of all the resins according to the present invention in the entire composition is preferably 40 to 99.99% by mass, more preferably 50 to 99.97, based on the total solid content of the resist. % By mass.

[2] Compound that generates acid upon irradiation with actinic ray or radiation The composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation (photoacid generator).

As such a photoacid generator, used as a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or a microresist, for example, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), known compounds that generate acids upon irradiation with actinic rays or radiation such as X-rays and electron beams, and mixtures thereof are appropriately used. You can select and use.

  For example, diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, onium salts such as arsonium salts, organic halogen compounds, organic metal / organic halides, photoacid generators having o-nitrobenzyl type protecting groups Examples thereof include disulfone compounds and compounds that generate photosulfonic acid by photolysis, such as agents and iminosulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407, JP 63-26653, JP 55-164824, JP 62-69263, JP 63-146038, JP 63-163452, JP 62-153853, JP 63- The compounds described in No. 146029 and the like can be used.

  Furthermore, 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.

  Examples of the photoacid generator include the following.

  (1) An iodonium salt represented by the following general formula (PAG1) or a sulfonium salt represented by the general formula (PAG2)

In the formula, Ar ¹ and Ar ² each independently represent an aryl group. Preferable substituents for the aryl group include an alkyl group, a cycloalkyl group, an alkoxy group, a nitro group, a carboxyl group, an alkoxycarbonyl group, a hydroxy group, a mercapto group, and a halogen atom.

R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represents an alkyl group or an aryl group. Preferred are aryl groups having 6 to 14 carbon atoms, alkyl groups having 1 to 8 carbon atoms, and substituted derivatives thereof. Preferred substituents are an aryl group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a nitro group, a carboxyl group, a hydroxy group, and a halogen atom. An alkoxy group having 1 to 8 carbon atoms, a carboxyl group, and an alkoxycarbonyl group;

Z ⁻ represents a counter anion, such as perfluoroalkanesulfonic acid anion such as BF ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , pentafluoro Examples include, but are not limited to, condensed polynuclear aromatic sulfonate anions such as benzenesulfonate 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.

  The above onium salts represented by the general formulas (PAG1) and (PAG2) are known, and can be synthesized, for example, by the methods described in US Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331.

  (2) A disulfone derivative represented by the following general formula (PAG3) or an iminosulfonate derivative represented by the general formula (PAG4)

In the formula, Ar ³ and Ar ⁴ each independently represents an aryl group. R ²⁰⁶ represents an alkyl group or an aryl group. A represents an alkylene group, an alkenylene group or an arylene group.

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

  (3) Diazodisulfone derivative represented by the following general formula (PAG5)

  In the formula, R represents an alkyl group, a cycloalkyl group, or an aryl group.

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

(B1) Triarylsulfonium Salt In the present invention, a triarylsulfonium salt (B1 component) is particularly preferable as the photoacid generator.

  The triarylsulfonium salt is a salt having triarylsulfonium as a cation.

  The aryl group of the triarylsulfonium cation is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The three aryl groups of the triarylsulfonium cation may be the same or different.

  Each aryl group has an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group as a substituent. You may have. Preferred substituents are an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms, and most preferably a methyl group, a butyl group, a t-butyl group, It is a C1-C4 alkoxy group. The substituent may be substituted with any one of the three aryl groups, or may be substituted with all three. The substituent is preferably substituted at the p-position of the aryl group.

  The anion of the triarylsulfonium salt is, for example, a sulfonate anion, preferably an alkane sulfonate anion substituted with a fluorine atom at the 1-position, or a benzene sulfonate substituted with an electron-withdrawing group, more preferably carbon. A perfluoroalkanesulfonic acid anion having a number of 1 to 8, most preferably a perfluorobutanesulfonic acid anion or a perfluorooctanesulfonic acid anion. By using these, the decomposition rate of the acid-decomposable group is improved, the sensitivity is excellent, the diffusibility of the generated acid is controlled, and the resolution is improved.

  The triarylsulfonium structure may have a plurality of triarylsulfonium structures bonded to another triarylsulfonium structure through a linking group such as -S-.

  Examples of the electron withdrawing group include a fluorine atom, a chlorine atom, a bromine atom, a nitro group, a cyano group, an alkoxycarbonyl group, an acyloxy group, and an acyl group.

  Specific examples of triarylsulfonium salts that can be used in the present invention are shown below, but the present invention is not limited thereto.

  Furthermore, the following compounds can be mentioned.

  (B2) Moreover, the compound (B2 component) represented by the following general formula (PAG6) is also preferable as a photoacid generator.

In the formula (PAG6),
R _{1 to} R ₅ represent a hydrogen atom, an alkyl group, an alkoxy group, a nitro group, a halogen atom, an alkyloxycarbonyl group or an aryl group, and at least two of R _{1 to} R ₅ are bonded to form a ring structure. It may be formed. R ₆ and R ₇ represent a hydrogen atom, an alkyl group, a cyano group, or an aryl group. Y ₁ and Y ₂ represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an aromatic group containing a hetero atom, and Y ₁ and Y ₂ may be bonded to form a ring. Y ₃ represents a single bond or a divalent linking group. X ⁻ represents a non-nucleophilic anion. At least one of R _{1 to} R ₅ may be bonded to at least one of Y ₁ or Y ₂ to form a ring, or at least one of R _{1 to} R ₅ and at least one of R ₆ or R ₇ may be bonded to each other. To form a ring. It may be bonded via a linking group at any position of R _{1 to} R ₇ , or any position of Y ₁ or Y ₂ , and may have two or more structures of the formula (PAG6).

The alkyl group of R _{1 to} R ₇ is preferably an alkyl group having 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, and a t-butyl group. Can be mentioned.

The alkoxy group in R _{1 to} R ₅ and the alkyloxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. .

The aryl group of R _{1 to} R ₇ , Y ₁ and Y ₂ is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a tolyl group, and a naphthyl group.

Examples of the halogen atom represented by R _{1 to} R ₅ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group for Y ₁ and Y ₂ is preferably a linear or branched alkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, Examples thereof include a t-butyl group.

The cycloalkyl group of Y ₁ and Y ₂ is preferably a cycloalkyl group having 3 to 30 carbon atoms, and examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group. it can.

The aralkyl group of Y ₁ and Y ₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a cumyl group.

  The aromatic group containing a hetero atom represents a group having a hetero atom, for example, a nitrogen atom, an oxygen atom, a sulfur atom, etc. in an aromatic group such as an aryl group having 6 to 14 carbon atoms.

Examples of the aromatic group containing a hetero atom of Y ₁ and Y ₂ include heterocyclic aromatic hydrocarbon groups such as furan, thiophene, pyrrole, pyridine, and indole.

Y ₁ and Y ₂ may combine to form a ring together with S ⁺ in formula (PAG6).

In this case, examples of the group formed by combining Y ₁ and Y ₂ include an alkylene group having 4 to 10 carbon atoms, preferably a butylene group, a pentylene group, and a hexylene group, and particularly preferably a butylene group and a pentylene group. Can be mentioned.

In addition, a ring formed by combining Y ₁ and Y ₂ together with S ⁺ in formula (PAG6) may contain a hetero atom.

  Each of the above alkyl group, cycloalkyl group, alkoxy group, alkoxycarbonyl group, aryl group, and aralkyl group is, for example, nitro group, halogen atom, carboxyl group, hydroxyl group, amino group, cyano group, alkoxy group (preferably carbon It may be substituted with formulas 1 to 5). Further, the aryl group and aralkyl group may be substituted with an alkyl group (preferably having 1 to 5 carbon atoms).

  Moreover, as a substituent of an alkyl group, a halogen atom is preferable.

Y ₃ represents a single bond or a divalent linking group, and examples of the divalent linking group include an optionally substituted alkylene group, alkenylene group, —O—, —S—, —CO—, —CONR—. (R is hydrogen, an alkyl group, or an acyl group.) And a linking group that may include two or more of these are preferable.

Examples of the non-nucleophilic anion X ⁻ include a sulfonate anion and a carboxylate anion.

  A non-nucleophilic anion is an anion having a remarkably low ability to cause a nucleophilic reaction, and is an anion capable of suppressing degradation with time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  The aliphatic group in the aliphatic sulfonate anion is preferably an alkyl group having 1 to 30 carbon atoms (for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, Pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl ), A cycloalkyl group having 3 to 30 carbon atoms (for example, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group).

  Preferred examples of the aromatic group in the aryl sulfonate anion include aryl groups having 6 to 14 carbon atoms such as a phenyl group, a tolyl group, and a naphthyl group.

  The alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent.

  Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, and an alkylthio group.

  Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

  As the alkyl group, for example, preferably an alkyl group having 1 to 15 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group Hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, etc. it can.

  As an alkoxy group, Preferably a C1-C5 alkoxy group, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. can be mentioned, for example.

  As the alkylthio group, for example, preferably an alkylthio group having 1 to 15 carbon atoms, such as methylthio group, ethylthio group, propylthio group, isopropylthio group, n-butylthio group, isobutylthio group, sec-butylthio group, pentylthio group, Neopentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, undecylthio, dodecylthio, tridecylthio, tetradecylthio, pentadecylthio, hexadecylthio, heptadecylthio, octadecylthio, nonadecylthio Group, eicosylthio group and the like. The alkyl group, alkoxy group, and alkylthio group may be further substituted with a halogen atom (preferably a fluorine atom).

  Examples of the aliphatic group in the aliphatic carboxylate anion include those similar to the aliphatic group in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aromatic groups as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.

  The aliphatic group, aromatic group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent include aromatic sulfonic acid. Examples of the anion include the same halogen atom, alkyl group, alkoxy group, alkylthio group and the like.

  Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

In the formula (PAG6) of the present invention, at least one of R ₁ to R ₅ and at least one of Y ₁ or Y ₂ are bonded to form a ring, or at least one of R ₁ to R ₅ and R _At least one of ₆ or R ₇ may be bonded to form a ring. The compound represented by the formula (PAG6) has a three-dimensional structure and improves optical resolution by forming a ring.

In addition, it may be bonded via a linking group at any position of R ₁ to R ₇ , or any position of Y ₁ or Y ₂ , and may have two or more structures of the formula (PAG6).

  Specific examples of the compound represented by the above formula (PAG6) are shown below, but the present invention is not limited thereto.

  In the specific example of the acid generator represented by the general formula (PAG6), (PAG6A-1) to (PAG6A-30) and (PAG6B-1) to (PAG6B-12) are more preferable.

  It is particularly preferable to use the component (B1) and the component (B2) in combination, and the ratio in this case is preferably 97/3 to 5/95, more preferably (B1) / (B2) (mass ratio). 90/10 to 10/90, particularly preferably 30/70 to 70/30.

  Among the acid generators used in the present invention, examples of particularly preferable ones are listed below.

  In the present invention, the photoacid generator is particularly preferably a compound that generates perfluorobutanesulfonic acid or perfluorooctanesulfonic acid.

  A photo-acid generator can be used individually by 1 type or in combination of 2 or more types.

  The total amount of the photoacid generator in the positive resist composition of the present invention is preferably 0.1 to 20% by mass, more preferably 0.5 to 20% by mass, and still more preferably, based on the solid content of the composition. Is 1 to 15% by mass.

[3] Compound of component (C) The positive resist composition of the present invention contains at least one compound selected from the following compounds (C1) to (C3).

  [3-1] (C1) Compound represented by the following general formula (VI-1), (VI-2) or (VI-3)

In general formula (VI-1),
R _1cc each independently represents a hydrogen atom, an alkyl group or an acyl group.

R _{2 cc} to R _{5 cc} each independently represents a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxyl group.

  Xa represents a single bond, a methylene group or an oxygen atom.

In general formulas (VI-2) and (VI-3),
R _1cc each independently represents a hydrogen atom, an alkyl group or an acyl group.

R _{1 cc,} an alkyl group of R _{2 cc} to R _{5 cc} is preferably 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group.

The acyl group of R _1cc is preferably an acyl group having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, and examples thereof include an acetyl group and a propionyl group.

Alkoxy group R _{2 cc} to R _{5 cc} is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably an alkoxy group having 1 to 3 carbon atoms, e.g., methoxy, ethoxy, and the like propoxy group it can.
.

  X is preferably a single bond or a methylene group.

  These groups may further have an alkyl group such as a methyl group or an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, a substituent such as a hydroxyl group or a halogen atom.

  Specific examples of the compound (C1) are shown below, but are not limited thereto.

  The compound (C1) is obtained by, for example, condensing a urea compound or glycoluril compound with formalin to introduce a methylol group, and then etherifying with a lower alcohol such as methyl alcohol, ethyl alcohol, propyl alcohol, or butyl alcohol, It can be obtained by cooling the reaction solution and collecting the precipitated compound or its resin. The compound (C4) can also be obtained as a commercial product such as CYMEL (trade name, manufactured by Mitsui Cyanamid) or Nicarad (manufactured by Sanwa Chemical).

  In the present invention, the compound (C1) is used in an amount of 3 to 70% by mass, preferably 5 to 50% by mass, based on the total solid content of the resist composition.

  [3-2] (C2) Compound represented by the following general formula (Za) or (Zb)

In general formulas (Za) to (Zb), R ^{1aa to} R ^4aa each independently represent a hydrogen atom, an alkyl group, or a cycloalkyl group. R ^1aa and R ^3aa , R ^2aa and R ^3aa may be bonded to each other to form a ring. R ^{1bb to} R ^3bb each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ^1bb and R ^3bb , R ^2bb and R ^3bb may combine with each other to form a ring. X represents a k-valent organic group. k represents an integer of 2 to 6.

The alkyl group of R ^{1aa to} R ^4aa and R ^{1bb to} R ^3bb is preferably an alkyl group having 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group.

The cycloalkyl group of R ^{1aa to} R ^4aa and R ^{1bb to} R ^3bb is preferably a cycloalkyl group having 3 to 6 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. it can.

R ^1aa and R ^3aa, R ^2aa and R ^3aa, R ^1bb and R ^3bb, R ^2bb and R ^3bb are Examples of the ring formed by bonding together, for example, a 4-6 membered ring.

  The organic group for X is preferably an aliphatic hydrocarbon group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group, more preferably an aliphatic hydrocarbon group or an alicyclic hydrocarbon group. Moreover, 2-20 are preferable. The organic group of X may intervene with a hetero atom such as an oxygen atom, and part or all of the hydrogen atom of the hydrocarbon group is substituted with a halogen atom such as F, Cl or Br, a hydroxyl group or an alkoxy group. It may be. The organic group of X has a valence corresponding to k. For example, when k = 2, X includes a linear, branched or cyclic alkylene group, an arylene group, an aralkylene group, and the like, such as an oxygen atom Heteroatoms may be present.

  An example of the structure of X is as follows. Examples of the bifunctional functional group include ethylene, propylene, isopropylene, and those having the following formula.

  Furthermore, the following are illustrated as a trifunctional thing.

  Examples of tetrafunctional compounds include the following.

  Examples of hexafunctional compounds include the following.

  The compound represented by the general formula (Za) has at least two groups represented by the following general formula (Zar).

  Specific examples of the group represented by the general formula (Zar) include an allyloxy group and a group represented by the following formula.

  An allyloxy group can be easily obtained by reacting an allyl halide with a hydroxyl group of a compound having two or more hydroxyl groups in the structure, but in the case of three or more functional groups, all hydroxyl groups can be reacted. Even if two or more hydroxyl groups are reacted and a hydroxyl group remains in the structure, it works effectively because a thermal crosslinking reaction occurs.

  In the case of four or more functional groups, the above-mentioned polyhydric alcohol can also include the following compounds. By reacting with allyl halide as described above, a compound having two or more allyloxy groups can be obtained. That is, polyhydric alcohols such as trayol, adonitol, arabitol, xylitol, sorbitol, mannitol, iditol, dulcid, fucose, ribose, arabinose, xylose, sorbose, mannose, galactose, glucose and the like, or isomers thereof. Can be included. All of the alcohol groups of these polyhydric alcohol compounds may be substituted with allyloxy groups, or two or more alcohols may be substituted with allyloxy groups. Moreover, some alcohols may be substituted with other groups.

  The addition amount of the compound represented by the general formula (Za) to the positive resist composition is preferably 0.1 to 5% by mass with respect to the entire resist system. More preferably, it is 0.5-2 mass%.

  The compound represented by the general formula (Za) preferably has a boiling point exceeding 200 ° C. under atmospheric pressure.

  The compound represented by the general formula (Zb) has at least two groups represented by the following general formula (Zbr).

  Specific examples of the group represented by the general formula (Zbr) include groups represented by the following formula.

  Hereinafter, although the specific example of a compound represented by general formula (Zb) is given, this invention is not limited to this.

  The addition amount of the compound represented by the general formula (Zb) to the positive resist composition is preferably 0.1 to 5% by mass with respect to the entire resist system. More preferably, it is 0.5-2 mass%.

  The compound represented by the general formula (Zb) preferably has a boiling point of over 200 ° C. under atmospheric pressure.

  In the compound of component (C2), k is an integer of 2 to 6, and preferably an integer of 3 to 4.

[3-3] (C3) Epoxy Compound The epoxy compound used in the present invention is preferably a compound having a boiling point of 180 ° C. or higher under atmospheric pressure and containing one epoxy group in the molecule. Examples of such an epoxy compound include 1,2-epoxy-4-hydroxymethylcyclohexane, 1,2-epoxy-4-vinylcyclohexane, 1,2-epoxy-3- (4-nitrophenoxy) propane, 2 , 3-epoxypropyl-4′-methoxyphenyl ether, 1,4-epoxy-1,4-dihydronaphthalene, 1,4-epoxy-1,2,3,4-tetrahydronaphthalene, 1,2-epoxycyclododecane , Epoxycyclooctane, glycidyl phenyl ether, glycidyl p-toluenesulfonate, glycidyl m-nitrobenzenesulfonate, phenylglycidol, 1,2-epoxy-5,9-cyclododecadiene, 1,2-epoxyhexadecane, exo-2 , 3-epoxynorbornane, 1,2-epoxyoct Tadecane, 2,3-epoxypropylbenzene, 1,2-epoxyoctadecane, 1,2-epoxytetradecane, 1,2-epoxy-5,9-cyclododecadiene, 1,2-epoxyhexadecane, N- (2, 3-epoxypropyl) phthalimide, furfuryl glycidyl ether, 3,4-epoxycyclohexylmethyl 6-hydroxyhexanoate, and the like, and an epoxy compound having an epoxycyclohexane skeleton in the molecule is preferable. These epoxy compounds can be used alone or in combination. The boiling point of the epoxy compound at atmospheric pressure is more preferably 200 ° C. or higher.

  The content of the epoxy compound is preferably 0.05 to 10 parts by mass and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the acid-decomposable resin.

  The compound (C) is preferably (C1) or (C2) among (C1) to (C3), more preferably (C1).

[4] (D) Solvent The resist composition of the present invention is obtained by dissolving the above-described components in a solvent.

  The solvent used in the present invention is preferably an organic solvent obtained by mixing a cyclic ketone with at least one selected from propylene glycol monoalkyl ether carboxylate, alkyl lactate and linear ketone.

  With respect to at least one selected from propylene glycol monoalkyl ether carboxylate, alkyl lactate and linear ketone and cyclic ketone, the ratio of addition amount (mass ratio) is preferably 10/90 to 90/10, more preferably 20/80. -80/20, more preferably 30 / 70-70 / 30.

  The content of the cyclic ketone is preferably 20 to 70% by mass and more preferably 30 to 60% by mass with respect to the total solvent.

  Preferred examples of the propylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate, and propylene glycol monoethyl ether propionate. Monomethyl ether acetate is particularly preferred.

  As the alkyl lactate, methyl lactate and ethyl lactate are preferable.

  Examples of the linear ketone include methyl ethyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, and preferably 2-heptanone.

  Examples of cyclic ketones include cyclopentanone, 3-methylcyclopentone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone, cycloheptane, 1,3-cycloheptadione, and γ-butyrolactone. Cyclopentanone, 3-methylcyclopentanone, cyclohexanone and cycloheptanone are preferred, and cyclopentanone and cyclohexanone are particularly preferred.

  Furthermore, other organic solvents may be used in combination in the range of usually 10% by mass or less with respect to the specific mixed solvent. Examples of such other organic solvents include ethylene carbonate, propylene carbonate, ethylene dichloride, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, Examples include toluene, ethyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and tetrahydrofuran.

  Using these mixed solvents, a resist composition having a solid content concentration of usually 3 to 25% by mass, preferably 5 to 22% by mass, and more preferably 7 to 20% by mass is prepared.

[5] (E) Nitrogen-containing basic compound The positive resist composition of the present invention preferably further contains a nitrogen-containing basic compound.

  As the nitrogen-containing basic compound, an organic amine, a basic ammonium salt, a basic sulfonium salt, or the like is used, as long as it does not deteriorate sublimation or resist performance.

  Among these nitrogen-containing basic compounds, organic amines are preferable in terms of excellent image performance. For example, JP-A-63-149640, JP-A-5-249662, JP-A-5-127369, JP-A-5-289322, JP-A-5-249683, JP-A-5-289340, JP-A-5-232706 JP-A-5-257282, JP-A-62-242605, JP-A-6-242606, JP-A-6-266100, JP-A-6-266110, JP-A-6-317902, JP-A-7-120929, JP-A-7-65558, JP-A-7-319163, JP-A-7-508840, JP-A-7-333844, JP-A-7-219217, JP-A-7-92678, JP-A-7-28247, Special Kaihei 8-22120, JP-A-811038, JP-A-8-1223030, JP-A-9-274312, JP-A-9-66871, JP-A-9-292708, JP-A-9-325496, Special table Basic compounds described in JP-A-7-508840, USP5525453, USP5629134, USP5667938 and the like can be used.

 Specific examples of the nitrogen-containing basic compound include structures of the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or 6 to 20 carbon atoms. Wherein R ²⁵¹ and R ²⁵² may combine with each other to form a ring. The alkyl group, cycloalkyl group, and aryl group may have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms and a hydroxyalkyl group having 1 to 20 carbon atoms. Examples of the cycloalkyl group having a substituent include an aminocycloalkyl group having 1 to 20 carbon atoms and a hydroxycycloalkyl group having 1 to 20 carbon atoms.

R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ may be the same or different and each represents an alkyl group having 1 to 10 carbon atoms.

  Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule, or aliphatic tertiary amines.

  The nitrogen-containing basic compound is preferably 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo. [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidines, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, anilines, hydroxyalkylanilines, 4,4′-diamino Diphenyl ether, pyridinium p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, and tetrabutylammonium lactate, triethylamine, tributylamine, tripentylamine, tri-n -Ok Triethanolamine, tri -i- octylamine, tris (ethylhexyl) amine, tridecyl amine, tridodecyl amine.

  Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, 4-hydroxypiperidine, 2,2,6,6-tetramethyl-4-hydroxypiperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, aniline 4,4′-diaminodiphenyl ether, triethylamine, tributylamine, tripentylamine, tri-n-octylamine, tris (ethylhexyl) amine, tridodecylamine, N, N-di-hydroxyethylaniline, N-hydroxyethyl -Organic amines such as N-ethylaniline are preferred There.

  The use ratio of the acid generator and the nitrogen-containing basic compound in the positive resist composition is usually (acid generator) / (nitrogen-containing basic compound) (molar ratio) = 2.5 to 300, preferably Is 5.0 to 200, more preferably 7.0 to 150.

  In the positive resist composition of the present invention, a low-molecular acid-decomposable compound, a surfactant, a dissolution-promoting compound for a developer, an antihalation agent, a plasticizer, a photosensitizer, and a surfactant, if necessary. , An adhesion assistant, a crosslinking agent, a photobase generator, and the like can be contained.

  The positive resist composition of the present invention has a low molecular acid decomposability that has a molecular weight of 2000 or less, a group that can be decomposed by the action of an acid, and an alkali solubility that is increased by the action of an acid, if necessary. Compounds can be included.

  For example, described in Proc. SPIE, 2724, 355 (1996), JP-A-8-15865, USP5310619, USP-5372912, J. Photopolym. Sci., Tech., Vol. 10, No. 3, 511 (1997)). Containing an acid-decomposable group, cholic acid derivative, dehydrocholic acid derivative, deoxycholic acid derivative, lithocholic acid derivative, ursocholic acid derivative, abietic acid derivative, etc. Aromatic compounds such as naphthalene derivatives can be used as the low-molecular acid-decomposable compound.

  Further, the low-molecular acid-decomposable dissolution inhibiting compound described in JP-A-6-51519 can also be used in an addition range at a level that does not deteriorate the permeability of 220 nm, and a 1,2-naphthoquinonediazite compound can also be used. .

  When the low molecular acid decomposable dissolution inhibiting compound is used in the resist composition of the present invention, the content thereof is usually in the range of 0.5 to 50 parts by mass based on 100 parts by mass (solid content) of the resist composition. Preferably 0.5 to 40 parts by mass, more preferably 0.5 to 30 parts by mass, and particularly preferably 0.5 to 20.0 parts by mass.

  Addition of these low molecular acid decomposable dissolution inhibiting compounds not only further improves the development defects, but also improves dry etching resistance.

  Examples of the dissolution promoting compound that can be used in the present invention include compounds containing two or more phenolic hydroxyl groups described in JP-A-3-206458, one naphthol such as 1-naphthol, or one carboxyl group. Examples thereof include low molecular compounds having a molecular weight of 1000 or less, such as compounds having the above, carboxylic acid anhydrides, sulfonamide compounds and sulfonylimide compounds.

  The blending amount of these dissolution promoting compounds is preferably 30% by mass or less, more preferably 20% by mass or less, based on the total mass (solid content) of the composition.

  As a suitable antihalation agent, a compound that efficiently absorbs irradiated radiation is preferable, and substituted benzenes such as fluorene, 9-fluorenone, and benzophenone; anthracene, anthracene-9-methanol, anthracene-9-carboxyethyl, phenanthrene , Polycyclic aromatic compounds such as perylene and azylene. Of these, polycyclic aromatic compounds are particularly preferred. These antihalation agents exhibit the effect of improving standing waves by reducing the reflected light from the substrate and reducing the influence of multiple reflection in the resist film.

  Moreover, in order to improve the acid generation rate by exposure, a photosensitizer can be added. Suitable photosensitizers include benzophenone, p, p′-tetramethyldiaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, pyrene, phenothiazine, benzyl, benzoflavine, acetophenone, phenanthrene, benzoquinone, anthraquinone, 1 , 2-naphthoquinone and the like, but are not limited thereto. These photosensitizers can also be used as the antihalation agent.

  The positive resist composition of the present invention comprises a surfactant, particularly a fluorine-based and / or silicon-based surfactant (a fluorine-based surfactant and a silicon-based surfactant, a surface activity containing both fluorine atoms and silicon atoms). It is preferable to contain any one of these, or two or more.

  When the positive resist composition of the present invention contains a fluorine-based and / or silicon-based surfactant, adhesion and development defects are obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It is possible to provide a resist pattern with less.

  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 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.

  Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon surfactant.

  In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive resist composition (excluding the solvent).

≪How to use≫
The positive resist composition of the present invention is used by dissolving the above components in a solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.

  That is, the above positive resist composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by an appropriate application method such as a spinner or coater to form a resist film. To do.

Next, the resist film is exposed through a predetermined mask, baked and developed. In this way, a good resist pattern can be obtained. Here, the exposure light is far ultraviolet rays having a wavelength of preferably 250 nm or less, more preferably 220 nm or less. 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 alkali developer for the positive resist composition include inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, and primary amines such as ethylamine and n-propylamine. Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide Alkaline aqueous solutions (usually 0.1-10 mass%), such as quaternary ammonium salts, such as cyclic amines, such as pyrrole and pihelidine, can be used.

  Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.

  The alkali concentration in the alkali developer is usually from 0.1 to 20% by mass.

  The pH of the alkaline developer is usually 10-15.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

  In the following synthesis examples, unless otherwise specified, the ratio and% are mass ratio and mass%.

Synthesis Example 1 (Synthesis of Resin (1))
2-adamantyl-2-propyl methacrylate, dihydroxyadamantane methacrylate, norbornane lactone acrylate, methacrylate are charged at a ratio of 30/20/40/10, dissolved in propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40, and solid 450 g of a solution having a partial concentration of 22% by mass was prepared. To this solution, 9 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added, and this was heated at 80 ° C. for 6 hours under a nitrogen atmosphere. Propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 The solution was added dropwise to 50 g of the mixed solution. After completion of dropping, the reaction solution was stirred for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the target resin (1).

^The polymer composition ratio (molar ratio) determined from ¹³ CNMR was a / b / c / d = 31/20/39/10. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 8010, and dispersion degree was 2.1. Moreover, as a result of performing DSC measurement, the glass transition point of resin (1) was 148 degreeC.

  Resins (1) to (11) and resins (12) to (13) used in Comparative Examples were synthesized according to Synthesis Example 1.

  Hereinafter, the structures of the resins (1) to (13) are shown.

  Table 1 below shows the composition ratio, the glass transition point, the molecular weight, and the degree of dispersion of the resins (1) to (13).

Examples 1 to 10 and Comparative Examples 1 to 3
(Preparation of positive resist composition)
1.03 g of resin,
Photoacid generator 0.00035 mol,
(C) 20 mg of the component compound,
Nitrogen-containing basic compound 1.65mg and surfactant 100ppm in total
Were dissolved in the solvent shown in Table 2 so that the solid content was 11% by mass, and then filtered through a 0.1 μm microfilter, and Examples 1 to 10 and Comparative Example 1 were mixed. -3 positive resist compositions were prepared. In Table 2, the ratio in the case of using a plurality of components is a molar ratio for the photoacid generator and a mass ratio for the others. Next, each positive resist composition was evaluated as follows. The evaluation results are shown in Table 2.

The symbol about a basic compound shows the following.
N-1: 1,5-diazabicyclo [4.3.0] non-5-ene
(DBN)
N-2: Triisodecylamine N-3: Trioctylamine N-4: Triphenylimidazole N-5: Antipyrine N-6: N, N-di-n-butylaniline N-7: Adamantylamine N-8 : Triisooctylamine

The symbol about surfactant shows the following.
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical 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: Troysol S-366 (manufactured by Troy Chemical Co., Ltd.)
Represents.

The symbols for the solvent are as follows.
SL-1: Propylene glycol monomethyl ether acetate SL-2: Ethyl lactate SL-3: Propylene glycol monomethyl ether SL-4: 2-heptanone SL-5: Cyclopentanone SL-6: Cyclohexanone SL-7: 2-Methylcyclohexanone SL-8: Propylene carbonate SL-9: γ-Butyrolactone

(Evaluation of sensitivity and resolution)
ARC29a manufactured by Brewer Science Co., Ltd. was uniformly applied to a silicon wafer with a spin coater at 780 Å, followed by heating and drying at 205 ° C. for 60 seconds to form an antireflection film. Thereafter, each positive resist composition was applied by a spin coater and dried at 120 ° C. for 90 seconds to form a 300 nm resist film.

  The resist film was exposed with an ArF excimer laser stepper (NA = 0.60 (σ = 0.70) manufactured by ISI) through a mask having a predetermined pattern, and heated on a hot plate at 120 ° C. for 90 seconds immediately after the exposure. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylmonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a pattern.

  Sensitivity was expressed by an exposure amount for reproducing a 0.15 μm line and space (1/1) pattern.

  Further, the minimum dimension (μm) of the resist pattern that is resolved when the exposure is performed with this exposure amount is defined as the resolving power.

(Thermal flow rate control evaluation)
ARC29a manufactured by Brewer Science Co., Ltd. was uniformly applied to a silicon wafer with a spin coater at 780 Å, followed by heating and drying at 205 ° C. for 60 seconds to form an antireflection film. Thereafter, each positive resist composition was applied by a spin coater and dried at 120 ° C. for 90 seconds to form a 300 nm resist film.

  The resist film is exposed with an ArF excimer laser stepper (NA = 0.60 (σ = 0.70) manufactured by ISI) attached with a contact hole pattern reticle, and immediately after exposure on a hot plate at 120 ° C. for 90 seconds. Further, the resist film was developed with a 2.38 mass% tetramethylmonium hydroxide aqueous solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a contact hole pattern. The contact hole size was 0.25 μm and the pitch was 1: 2.

  By this method, a positive resist composition was applied on a dozen silicon wafers to form a contact hole pattern. Thereafter, heat treatment was performed to reduce the thermal flow, that is, the contact hole. The heat treatment was performed on a hot plate for 90 seconds while changing the temperature of each wafer by 2 ° C.

  The size of the contact hole after the heat treatment was measured using a scanning electron microscope (TopDown SEM). A graph was created with each heat treatment temperature on the horizontal axis and the contact hole size for each heat treatment temperature on the vertical axis. The contact hole size before the heat treatment was 0.25 μm, but the temperature at which the contact hole size became 0.15 μm was determined from the graph.

  Further, the gradient (flow rate) of the thermal flow at a size of 0.15 μm was obtained from the graph. The smaller the flow rate, the more effectively the thermal flow process can be controlled, and it can be determined that it is preferable.

(Particle number evaluation)
For each positive resist composition, the number of particles in the solution immediately after preparation (particle initial value) and the number of particles in the solution after storage at 4 ° C. for 1 week (number of particles after storage over time) are manufactured by Rion. Counted with a particle counter. Along with the initial particle value, the number of particles increased at the time of storage calculated by (number of particles after storage over time) − (initial particle value) was evaluated.

  From Table 2, it is clear that the positive resist composition of the present invention simultaneously satisfies the resolution, sensitivity, thermal flow rate control, reduction of the initial particle value, and reduction of the number of particles during storage with time.

Claims (7)

(A) a resin having the following four types of repeating units (A-1) to (A-4) and having increased solubility in an alkali developer by the action of an acid;
(A-1) At least one repeating unit selected from repeating units represented by the following general formula (I):
(A-2) at least one type of repeating unit selected from repeating units having groups represented by the following general formulas (II-1) to (II-4);
(A-3) at least one repeating unit selected from repeating units represented by the following general formula (III) and (A-4) 2-alkyl-2-adamantyl group or 1-adamantyl-1-alkylalkyl group At least one repeating unit selected from repeating units having:
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) at least one compound selected from the following three types of compounds (C1) to (C3) and (C1) a compound represented by the following general formulas (VI-1) to (VI-3),
(C2) a compound represented by the following general formula (Za) or (Zb) and (C3) an epoxy compound,
(D) A positive resist composition containing a solvent.
In general formula (I), R _1a represents a hydrogen atom or a methyl group. W ₁ represents a single bond or a divalent linking group.
In general formulas (II-1) to (II-4), R _{1b to} R _5b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. Two of R _{1b to} R _5b may combine to form a ring.
In general formula (III), R _1c represents a hydrogen atom or a methyl group. R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.
In general formulas (VI-1) to (VI-3), R _1cc each independently represents a hydrogen atom, an alkyl group, or an acyl group. R _{2 cc} to R _{5 cc} each independently represents a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group. Xa represents a single bond, a methylene group or an oxygen atom.
In general formulas (Za) to (Zb), R ^{1aa to} R ^4aa each independently represent a hydrogen atom, an alkyl group, or a cycloalkyl group. R ^1aa and R ^3aa , R ^2aa and R ^3aa may be bonded to each other to form a ring. R ^{1bb to} R ^3bb each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ^1bb and R ^3bb , R ^2bb and R ^3bb may combine with each other to form a ring. X represents a k-valent organic group. k represents an integer of 2 to 6.   (B) The positive resist composition according to claim 1, comprising a triarylsulfonium salt as a compound that generates an acid upon irradiation with actinic rays or radiation.   The positive resist composition according to claim 1, further comprising (E) a nitrogen-containing basic compound.   The positive transition resist composition according to any one of claims 1 to 3, wherein the glass transition temperature of the resin (A) is 70 to 150 ° C.   The positive resist composition according to claim 1, wherein the positive resist composition is used for thermal flow.   The repeating unit (A-4) is a repeating unit having a 2-alkyl-2-adamantyl group, and the repeating unit (A-3) is a repeating unit having a dihydroxyadamantyl group. The positive resist composition for thermal flow according to claim 5.   A pattern forming method comprising the steps of: forming a resist film from the positive resist composition according to claim 1; and exposing and developing the resist film.