JP2005025178A - Positive-working resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive-working resist composition which suppresses pattern falling when a fine pattern is resolved and has an improved PED (post exposure delay) stability, line edge roughness, profile, sensitivity and resolving power, and to provide a pattern forming method using the same. <P>SOLUTION: The positive-working resist composition comprises (A) a resin whose solubility in an alkali developing solution is increased by the action of an acid, (B) a compound which generates an acid upon irradiation with an actinic ray or radiation, (C) a nonionic cyclic compound having a specified partial structure and satisfying at least a melting point of ≥35°C or a boiling point of ≥100°C/10 mmHg, and (D) a solvent. The pattern forming method uses the positive-working resist composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a positive resist composition used in semiconductor manufacturing processes such as ICs, circuit boards such as liquid crystals and thermal heads, and other photofabrication processes, and a pattern forming method using the same. . More particularly, the present invention relates to a positive resist composition suitable for using far ultraviolet rays of 250 nm or less as an exposure light source and a pattern forming method using the same.

  The chemically amplified resist composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and the acid-catalyzed reaction causes the solubility of the active radiation irradiated area and non-irradiated area in the developer. It is a pattern forming material that changes and forms a pattern on a substrate.

  Regarding a chemically amplified resist composition, Patent Document 1 (JP-A-6-130665) describes a resist composition containing a compound having a carbonyl group as a solvent, and Patent Document 2 (JP-A 2002-2002). 148784) describes a resist composition containing octanone as an additive.

  However, the conventional resist composition has a problem that, when trying to resolve a fine pattern, pattern collapse occurs and image performance becomes insufficient.

JP-A-6-130665 JP 2002-148784 A

An object of the present invention is to provide a positive resist composition that suppresses pattern collapse when attempting to resolve a fine pattern and a pattern forming method using the same.
Furthermore, the present invention can provide a positive resist composition having improved PED stability, line edge roughness, profile, sensitivity, and resolution, and a pattern forming method using the same.

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

(1) (A) a resin whose solubility 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,
(C) a non-ion having at least one partial structure represented by the following general formula (I) or (II) and having a melting point of 35 ° C. or higher or a boiling point of at least 100 ° C./10 mmHg or higher A positive resist composition comprising a functional cyclic compound and (D) a solvent.

  (2) The nonionic cyclic compound of component (C) has an alicyclic structure or a bridged alicyclic structure, and at least one ring constituting the alicyclic structure or the bridged alicyclic structure is The positive resist composition as described in (1), which has at least one partial structure represented by the general formula (I) or (II).

  (3) The positive resist composition as described in (2), wherein the nonionic cyclic compound of component (C) has a bridged alicyclic structure and does not have a benzene ring.

  (4) The nonionic cyclic compound of component (C) has two or more partial structures represented by the above general formula (I) and has no benzene ring and the above general formula (II) The positive resist composition according to any one of (1) to (3), wherein the positive resist composition is selected from compounds having at least one partial structure represented and having no benzene ring.

  (5) The positive resist composition as described in any one of (1) to (4), further comprising (E) a nitrogen-containing basic compound.

  (6) A pattern forming method comprising a step of forming a resist film from the positive resist composition according to any one of (1) to (5), and exposing and developing the resist film.

The preferred embodiments of the present invention will be further described below.
(7) The atoms constituting the nonionic cyclic compound of component (C) are composed of only carbon atoms and hydrogen atoms in addition to the partial structure represented by the general formula (I) or (II). The positive resist composition according to any one of (1) to (5).

  (8) The positive resist composition as described in any one of (1) to (5) and (7), wherein the resin of component (A) has an alicyclic structure or a bridged alicyclic structure.

  (9) The resin of component (A) is a resin having an alkali-soluble group protected by a 2-alkyl-2-adamantyl group or a 1-adamantyl-1-alkylalkyl group (8) The positive resist composition as described in 1. above.

  (10) The positive resist composition as described in (8) or (9), wherein the resin of component (A) is a resin having a repeating unit represented by the following general formula (III) .

In general formula (III),
R _1a represents a hydrogen atom, an alkyl group or a halogen atom.
R _2a represents a hydrogen atom or an alkyl group.

  (11) The positive resist composition as described in any one of (8) to (10), wherein at least one of the bridged alicyclic structures of the resin of component (A) is dihydroxyadamantane.

  According to the present invention, a positive resist composition that suppresses pattern collapse when attempting to resolve a fine pattern and has improved PED stability, line edge roughness, profile, sensitivity, and resolution, and a pattern using the same A forming method can be provided.

Hereinafter, the present invention will be described in detail.
In addition, in the description of the group (atomic group) in this specification, the notation 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 whose solubility in an alkaline developer is increased by the action of an acid The positive resist composition of the present invention contains a resin whose solubility in an alkaline developer is increased by the action of an acid.
When the positive resist composition of the present invention is irradiated with ArF excimer laser light, a resin whose solubility in an alkaline developer is increased by the action of an acid has an alicyclic structure or a bridged alicyclic structure, A resin (hereinafter also referred to as “acid-decomposable resin”) whose solubility in an alkaline developer is increased by the action is preferable.
The acid-decomposable resin has, for example, a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI), and has solubility in an alkali developer due to the action of an acid. Increasing resins are preferred.

In the formula, R ₁₁ 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 _{12 to} R ₁₆ 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 _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ 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 _{17 to} R ₂₁ Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 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 _{22 to} R ₂₅ Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the general formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ 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.

The alicyclic hydrocarbon group in R _{11 to} R _{25 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 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. The alkyl group and alkoxy group may have a substituent. Examples of the substituent for 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 (pVI) 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.
Preferred examples of the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the resin include groups represented by the following general formulas (pVII) to (pXI).

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 (pVI) 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 (pVI).

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

The acid-decomposable resin preferably has a repeating unit having an alkali-soluble group protected by a 2-alkyl-2-adamantyl group such as a repeating unit formed by the monomers 1 to 4 and 32.
The acid-decomposable resin preferably has a repeating unit having an alkali-soluble group protected by a 1-adamantyl-1-alkylalkyl group such as a repeating unit formed by the monomers 5 to 8.

The resin according to the present invention contains a group (hereinafter also referred to as “acid-decomposable group”) that is insoluble or hardly soluble in alkali and decomposes by the action of an acid to become alkali-soluble.
The acid-decomposable group is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI) and at least one repeating unit among the repeating units of the copolymerization component described later. It can be contained in the unit.

The structure of the acid-decomposable group is represented by —C (═O) —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 preferably further has a repeating unit having a group represented by the following general formula (AI).

In general formula (AI), 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.

  The group represented by the general formula (AI) is preferably a dihydroxy form or a monohydroxy form, and more preferably a dihydroxy form.

  Examples of the repeating unit having a group represented by the general formula (AI) include a repeating unit represented by the following general formula (AII).

In general formula (AII), 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.

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

  The acid-decomposable resin can further contain a repeating unit having a lactone structure represented by the following general formula (IV).

In general formula (IV), R _1aa represents a hydrogen atom or a methyl group.
W ₁ represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, or a group of two or more groups selected from the group consisting of an ester group.
Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. m and n each independently represents an integer of 0 to 3, and m + n is 2 or more and 6 or less.

Examples of the alkyl group having 1 to 4 carbon atoms of Ra _{1 to} Re ₁ include 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. Can do.

In the general formula (IV), 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, 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 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.

  The alkyl group and alkoxy group may have a substituent. Examples of further substituents in the alkyl group and the alkoxy group include a carboxyl group, an acyloxy group, a cyano group, an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, an acetylamide group, an alkoxycarbonyl group, and an acyl group.

  Specific examples of the repeating unit represented by the general formula (IV) are shown below, but are not limited thereto.

In the specific example of the general formula (IV), (IV-17) to (IV-36) are preferable because the exposure margin becomes better.
Further, as the structure of the general formula (IV), those having an acrylate structure are preferable from the viewpoint that the edge roughness becomes good.

  The acid-decomposable resin may have a repeating unit having a group represented by any one of the following general formulas (V-1) to (V-4).

In General Formulas (V-1) to (V-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 the general formulas (V-1) to (V-4), examples of the alkyl group in R _{1b to} R _5b include linear and branched alkyl groups.
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 (V-1) to (V-4), R _{1b to} R _5b may be connected to any carbon atom constituting the cyclic skeleton.

  The alkyl group, cycloalkyl group, and alkenyl group may have a substituent. Preferred substituents that the alkyl group, cycloalkyl group, and alkenyl group may have include an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), and 2 carbon atoms. -5 acyl groups, acyloxy groups having 2 to 5 carbon atoms, cyano groups, hydroxyl groups, carboxy groups, alkoxycarbonyl groups having 2 to 5 carbon atoms, nitro groups, and the like.

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

In general formula (V), _Rb0 represents a hydrogen atom, a halogen atom, or a C1-C4 alkyl group. The alkyl group for R _b0 may have a substituent. 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 (V-1) to (V-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 _b represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.
V represents a group represented by any one of the general formulas (V-1) to (V-4).
In A _b, examples of the divalent group in combination the include for example those of the following formulas.

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 the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. The alkyl group and alkoxy group may have a substituent. Examples of the substituent for the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms. 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.

  Specific examples of the repeating unit represented by the general formula (V) are shown below, but the contents of the present invention are not limited to these.

  The acid-decomposable resin of the present invention preferably has a repeating unit represented by the following general formula (III).

In general formula (III),
R _1a represents a hydrogen atom, an alkyl group or a halogen atom.
R _2a represents a hydrogen atom or an alkyl group.

The alkyl group of R _1a and R _2a is preferably a linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a sec-butyl group. , T-butyl group and the like.
The alkyl group of R _1a and R _2a may be substituted with a halogen atom (preferably a fluorine atom) or the like.
Examples of the halogen atom for R _1a include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Specific examples of the repeating unit represented by the general formula (III) include the following repeating units.

  Moreover, the acid-decomposable resin of the present invention can further contain a repeating unit represented by the following general formula (VI).

In the general formula (VI), 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 (VI), 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, 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 the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. The alkyl group and alkoxy group may have a substituent. Examples of the substituent for the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group. r is an integer of 1-10.
In the general formula (VI), 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 the general formula (VI), 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 (VI) below is given, it is not limited to these.

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

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 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.

  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 acid-decomposable resins, the molar ratio of each repeating unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance required for resolution, heat resistance, sensitivity, etc. It is set appropriately to adjust.

  In the acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) is preferably 30 to 70 mol% in all repeating units. Preferably it is 35-65 mol%, More preferably, it is 40-60 mol%.

Further, the content of the repeating 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 (pI) It is preferably 99 mol% or less, more preferably 90 mol% or less, still more preferably 80 mol% or less, based on the number of moles of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by (pVI). is there.
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.

  In the acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably from 15 to 50 mol%, more preferably from 20 to 40 mol%, based on all repeating units.

The (A) acid-decomposable resin 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 further dissolved in a solvent for dissolving the composition of the present invention such as propylene glycol monomethyl ether acetate described later, 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 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50-100 ° C.

The repeating structural units represented by the above specific examples may be used singly or in combination.
In the present invention, the (A) resin may be used alone or in combination.

The weight average molecular weight of the (A) resin according to the present invention is usually 1,000 to 200,000, more preferably 3,000 to 20,000, as a polystyrene converted value by the GPC method.
The molecular weight distribution (Mw / Mn) is usually 1 to 10, preferably 1 to 5, and more preferably 1 to 4. The smaller the molecular weight distribution, the smoother the resolution, the resist shape, and the side wall of the resist pattern, and the better the roughness.

  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] (B) Compound that generates acid upon irradiation with actinic ray or radiation The positive resist composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter also referred to as “acid generator”). ).
As an acid generator, photo-initiator for photo-cationic polymerization, photo-initiator for photo-radical polymerization, photo-decoloring agent for dyes, photo-discoloring agent, or acid generated by irradiation of radiation used for micro-resist The known compounds to be used and mixtures thereof can be appropriately selected and used.

  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, acid generators having o-nitrobenzyl type protecting groups And compounds capable of generating sulfonic acid by photolysis represented by imino sulfonate and the like, and disulfone compounds.

  Further, a group that generates an acid by irradiation of these radiations, or a compound in which a compound is introduced into the main chain or side chain of the polymer, such as US Pat. No. 3,849,137, German Patent No. 3914407, JP-A 63-26653 JP, 55-164824, JP 62-69263, JP 63-146038, JP 63-163452, JP 62-153853, JP 63-146029, etc. Can be used.

  Furthermore, compounds described in US Pat. No. 3,779,778, European Patent 126,712, and the like can also be used.

  Of the acid generators, those that are effectively used will be described below.

  (1) Compound represented by the following general formula (PAGI) (hereinafter also referred to as “acid generator (PAGI)”)

In General Formula (PAGI), R ₁ and R ₂ may be the same or different and each represents an alkyl group, a cycloalkyl group, an aryl group, or a group having a heterocyclic structure. R ₁ and R ₂ may be linked to form a ring. R ₃ and R ₄ may be the same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. R ₃ and R ₄ may be linked to form a ring. X represents an alkyl group, an aryl group, an alicyclic hydrocarbon group, a group having a heterocyclic structure, or a combination thereof. However, at least one of R _{1 to} R ₄ and X is an alkyl group or cycloalkyl group having 7 or more carbon atoms, or at least one of R _{1 to} R ₄ and X has 7 carbon atoms. One or more alkyl groups or cycloalkyl groups are included as substituents. Q ₁ represents an alkyl group substituted with a fluorine atom, a cycloalkyl group substituted with a fluorine atom, an aryl group substituted with a fluorine atom, or an aryl group substituted with a fluorinated alkyl group.

The alkyl group of R _{1 to} R ₄ is preferably an alkyl group having 1 to 30 carbon atoms. Examples of the alkyl group for R _{1 to} R ₄ include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group. And linear or branched alkyl groups such as a group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, and a tetradecyl group.

The cycloalkyl group represented by R _{1 to} R ₄ 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. Can do.

The aryl group of R _{1 to} R ₄ and X 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.

The heterocyclic structure in the group having a heterocyclic structure of R ₁ , R ₂ and X is a cyclic structure having a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom in the ring. For example, furan, thiophene Further, a structure in which a benzene ring is condensed to these, for example, benzofuran, benzothiophene and the like can be mentioned.

R ₁ and R ₂ may be linked to form a ring.
R ₃ and R ₄ may be linked to form a ring.
In this case, the group formed by connecting R ₁ and R ₂ , R ₃ and R ₄ is, for example, an alkylene group having 4 to 10 carbon atoms, preferably a butylene group, a pentylene group or a hexylene group, particularly preferably A butylene group and a pentylene group can be exemplified.
A carbonyl group, an oxygen atom, a sulfur atom and the like may be present in the ring formed by linking R ₁ and R ₂ , R ₃ and R ₄ .

The alkyl group of X is preferably an alkyl group having 1 to 30 carbon atoms, for example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group. Examples thereof include linear or branched alkyl groups such as a group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, and tetradecyl group.

  The alicyclic hydrocarbon group of X is preferably an alicyclic hydrocarbon group having 3 to 30 carbon atoms. For example, an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, norbornyl Group, cedrol group, cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, cyclododecanyl group and the like.

  Examples of the combination of an alkyl group, an aryl group, an alicyclic hydrocarbon group, and a group having a heterocyclic structure in X include, for example, at least one of an aryl group, an alicyclic hydrocarbon group, and a group having a heterocyclic structure. At least one of at least one of a substituted alkyl group, an alkyl group, an alicyclic hydrocarbon group, and a group having a heterocyclic structure is a substituted aryl group, an alkyl group, an aryl group, or a group having a heterocyclic structure. And a group having a heterocyclic structure in which at least one of alicyclic hydrocarbon groups, alkyl groups, aryl groups and alicyclic hydrocarbon groups substituted by one is substituted.

Each of the above-mentioned alkyl group, cycloalkyl group, aryl group, alicyclic hydrocarbon group, group having a heterocyclic structure, R ₁ and R ₂ , R ₃ and R ₄ linked to each other is, for example, nitro Group, halogen atom, carboxyl group, hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 12 carbon atoms) and the like. Further, for the ring formed by linking R ₁ and R ₂ , R ₃ and R ₄ , a cycloalkyl group, an aryl group, an alicyclic hydrocarbon group, a group having a heterocyclic structure, an alkyl group (preferably having 1 carbon atom). ˜30) may be substituted. An alkyl group, a cycloalkyl group, an alicyclic hydrocarbon group, a group having a heterocyclic structure, a ring formed by connecting R ₁ and R ₂ , R ₃ and R ₄ may be substituted with an aryl group. .

The alkyl group in Q ₁ 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. 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. Can be mentioned.
Preferred examples of the cycloalkyl group for Q ₁ include a cycloalkyl group having 3 to 30 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group. .
The aryl group in Q ₁ is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.
The fluorinated alkyl group in Q ₁ is preferably a fluorinated alkyl group having 1 to 5 carbon atoms, and examples thereof include a trifluoromethyl group, a difluoromethyl group, a monofluoromethyl group, and a pentafluoroethyl group. Can do.
The alkyl group, cycloalkyl group and aryl group in Q ₁ may have a further substituent. Examples of the further substituent include a halogen atom (excluding a fluorine atom), an alkyl group, an alkoxy group, and an alkylthio group.

In the acid generator (PAGI), at least one of R _{1 to} R ₄ and X is an alkyl group or cycloalkyl group having 7 or more carbon atoms, or at least one of R _{1 to} R ₄ and X. In addition, an alkyl group or cycloalkyl group having 7 or more carbon atoms is included as a substituent.
In addition, the alkyl group in a substituent shall also contain the alkyl group in an alkoxy group.

In the acid generator (PAGI), at least one of R ₃ and R ₄ is an alkyl group or a cycloalkyl group having 7 or more carbon atoms, or at least one of R ₃ , R ₄ and X It is preferable that an alkyl group or cycloalkyl group having 7 or more carbon atoms is contained as a substituent, and X has a benzene ring.

In the acid generator (PAGI), at least one of R ₁ and R ₂ is an alkyl group or a cycloalkyl group having 7 or more carbon atoms, or at least one of R ₁ and R ₂ has a carbon number. It is preferable that 7 or more alkyl groups or cycloalkyl groups are included as a substituent, and X does not have a benzene ring.

In the acid generator (PAGI), at least one of R ₁ and R ₂ is an alkyl group or a cycloalkyl group having 7 or more carbon atoms, or at least one of R ₁ and R ₂ has a carbon number. Is preferably characterized in that 7 or more alkyl groups or cycloalkyl groups are contained as a substituent, and X has a benzene ring, and the benzene ring has a substituent and / or a condensed ring group.
Examples of the condensed group that the benzene ring may have include 1 to 5 benzene rings and a cyclohexane ring formed on the benzene ring.

  Hereinafter, although the specific example of an acid generator (PAGI) is given, this invention is not limited to this.

  (2) Compound represented by the following general formula (PAGII) (hereinafter also referred to as “acid generator (PAGII)”)

In General Formula (PAGII), R ₅ represents an alkyl group, an alicyclic hydrocarbon group, a hydroxyl group, a carboxyl group, an alkoxy group, or a halogen atom. y represents each independently 0 or an integer of 1-5. When y is an integer of 2 or more, two or more R _{5 s} may be the same or different. Q ₂ represents an alkyl group substituted with a fluorine atom, a cycloalkyl group substituted with a fluorine atom, an aryl group substituted with a fluorine atom, or an aryl group substituted with a fluorinated alkyl group.

In the alkyl group in the alkoxy group of the alkyl group and R ₅ in R ₅ is preferably alkyl group having 1 to 6 carbon atoms, such as methyl group, ethyl group, propyl group, n- butyl group, sec- Examples thereof include linear or branched alkyl groups such as a butyl group, a t-butyl group, a pentyl group, and a hexyl group.
The alicyclic hydrocarbon group for R ₅ is preferably an alicyclic hydrocarbon group having 3 to 6 carbon atoms, and examples thereof include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group.
Examples of the halogen atom for R ₅ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Q ₂ is the same as Q ₁ in the general formula (PAGI).

  Hereinafter, although the specific example of an acid generator (PAGII) is given, this invention is not limited to this.

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

Here, Ar ¹ and Ar ² each independently represents an aryl group. The aryl group of Ar ¹ and Ar ² may have a substituent. Preferable substituents include an alkyl group, a haloalkyl group, a cycloalkyl group, an aryl 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, a cycloalkyl group or an aryl group. Preferred are an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and substituted derivatives thereof.
Preferred substituents for the aryl group are an alkoxy 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, and an alkyl group and a cycloalkyl group. Is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group, or an alkoxycarbonyl group.

Z ⁻ represents a counter anion, for example, BF ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , ClO ₄ ⁻ , alkanesulfonic acid anion, benzenesulfonic acid anion, naphthalene-1-sulfonic acid Examples include, but are not limited to, condensed polynuclear aromatic sulfonate anions such as anions, anthraquinone sulfonate anions, 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 U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331.

  (4) 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.

  (5) A diazodisulfone derivative represented by the following general formula (PAG5)

Here, each R independently represents an alkyl group, a cycloalkyl group, or an aryl group.
Specific examples include the following compounds, but are not limited thereto.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The acid generator is preferably an acid generator (PAGII).
The content of the acid generator in the positive resist composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 20% by mass, and still more preferably 1 to 15%, based on the solid content of the composition. % By mass.

[3] (C) having at least one partial structure represented by the following general formula (I) or (II), having a melting point of 35 ° C. or higher, or a boiling point of 100 ° C./10 mmHg or higher. Nonionic cyclic compound to be filled The positive resist composition of the present invention has at least one partial structure represented by the following general formula (I) or (II) and has a melting point of 35 ° C. or higher, or a boiling point, A nonionic cyclic compound (hereinafter also referred to as “compound of component (C)”) satisfying at least one of 100 ° C./10 mmHg or more is contained.

The compound of the component (C) has an alicyclic structure or a bridged alicyclic structure, and at least one ring constituting the alicyclic structure or the bridged alicyclic structure has the above general formula (I) or It is preferable to have at least one partial structure represented by (II).
The compound of component (C) has an alicyclic structure or a bridged alicyclic structure selected from the group consisting of 4-membered rings to 15-membered rings and selected from a combination of at least one ring or two or more rings. It is preferable that it has an alicyclic structure or a bridged alicyclic structure selected from a combination of 2 to 10 rings, and an alicyclic structure or a bridged alicyclic structure selected from a combination of 2 to 8 rings. It is particularly preferred to have
The compound of component (C) preferably has a bridged alicyclic structure and does not have a benzene ring.
Does the compound of component (C) have 2 or more, preferably 2 to 10, and particularly preferably 2 to 8 partial structures represented by the above general formula (I) and does not have a benzene ring? Alternatively, it is preferable to have at least one partial structure represented by the general formula (II) and not have a benzene ring.
In addition to the partial structure represented by the above general formula (I) or (II), the atoms constituting the compound of component (C) are preferably composed of only carbon atoms and hydrogen atoms.

The melting point of the compound (C) is preferably 35 ° C. or higher and 300 ° C. or lower, more preferably 35 ° C. or higher and 270 ° C. or lower.
The boiling point of the compound (C) is preferably 100 ° C./10 mmHg or more and 100 ° C./1 mmHg or less, more preferably 100 ° C./10 mmHg or more and 100 ° C./2 mmHg or less.
The molecular weight of the compound (C) is preferably 95 or more and 1500 or less, and more preferably 110 or more and 1000 or less.

  Hereinafter, although the specific example of the compound of (C) component is given, this invention is not limited to this.

  The compound of (C) component can be used individually by 1 type or in combination of 2 or more types. The content of the compound (C) in the positive resist composition is preferably 0.05 to 10.0% by mass, more preferably 0.07 to 8.0% by mass, based on the solid content of the composition. More preferably, it is 0.10 to 7.0 mass%.

[4] (E) Nitrogen-containing basic compound Next, the positive resist composition of the present invention preferably contains (E) a nitrogen-containing basic compound. (E) As a 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 preferred because 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.

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, piperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, 4,4′-diaminodiphenyl ether, pyridinium p-toluenesulfonate, Examples include 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium lactate, triethylamine, and tributylamine.
Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Organic amines such as octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, 4,4′-diaminodiphenyl ether, triethylamine, and tributylamine are preferred.

  (E) The content of the nitrogen-containing basic compound is usually 0.001 to 10 parts by mass, preferably 0.001 to 5 parts by mass, more preferably 100 parts by mass of the positive resist composition (solid content). Is 0.001 to 0.5 parts by mass.

[5] (F) Fluorine-based and / or silicon-based surfactant The positive resist composition of the present invention further comprises (F) fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based interface). It is preferable to contain any one or two or more of activators and surfactants containing both fluorine atoms and silicon atoms.
When the positive resist composition of the present invention contains the surfactant (F), when using an exposure light source of 250 nm or less, particularly 220 nm or less, good sensitivity and resolution, and less adhesion and development defects. A resist pattern can be provided.
As these (F) surfactants, for example, JP-A 62-36663, JP-A 61-226746, JP-A 61-226745, JP-A 62-170950, JP No. 63-34540, 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-based 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 link) or poly (block link of oxyethylene and oxypropylene) 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.

  (F) 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).

[6] (D) Solvent In the present invention, a positive resist composition is prepared by dissolving the above components in a solvent. In the present invention, the solvent refers to a solvent which is liquid under conditions of 25 ° C. and 760 mmHg and has a boiling point of 250 ° C. or less.
The positive resist composition of the present invention preferably uses a mixed solvent as the solvent (D). As the mixed solvent, at least one of propylene glycol monoalkyl ether carboxylates (also referred to as group A solvent) and at least one of propylene glycol monoalkyl ether, alkyl lactate and alkyl alkoxypropionate (group B). And / or a mixed solvent containing at least one of γ-butyrolactone, ethylene carbonate, propylene carbonate, and cyclohexanone (also referred to as a group C solvent). That is, as a mixed solvent, a combination of a group A solvent and a group B solvent, a combination of a group A solvent and a group C solvent, a combination of a group A solvent, a group B solvent, and a group C solvent. Can be used.

  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.

  Preferred examples of the propylene glycol monoalkyl ether include propylene glycol monomethyl ether and propylene glycol monoethyl ether. Preferable examples of the alkyl lactate include methyl lactate and ethyl lactate. Preferred examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, and methyl 3-ethoxypropionate.

The mass ratio (A: B) of the group A solvent and the group B solvent is preferably 90:10 to 15:85, more preferably 85:15 to 20:80, and still more preferably 80:20. ~ 25: 75.
The use mass ratio (A: C) of the group A solvent and the group C solvent is preferably 99.9: 0.1 to 30:70, more preferably 99: 1 to 40:60, and even more preferably. Is 97: 3-50: 50.

When combining these three solvents, the mass ratio of the group C solvent is preferably from 0.1 to 50 mass%, more preferably from 1 to 48 mass%, still more preferably from 3 to 3 mass% based on the total solvent. 45% by mass.
In the present invention, the solid content of the composition containing the above components is preferably dissolved in the mixed solvent in a solid content concentration of 3 to 25% by mass, more preferably 5 to 22% by mass, and still more preferably 7 ˜20 mass%.

As a preferable combination of the mixed solvent containing propylene glycol monoalkyl ether carboxylate in the present invention,
Propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether Propylene glycol monomethyl ether acetate + ethyl lactate Propylene glycol monomethyl ether acetate + 3-ethoxyethyl propionate Propylene glycol monomethyl ether acetate + γ-butyrolactone Propylene glycol monomethyl ether acetate + ethylene carbonate Propylene glycol monomethyl ether Acetate + propylene carbonate Propylene glycol monomethyl ether acetate + cyclohexanone Propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + γ-butyrolactone Propylene glycol monomethyl ether acetate Ethyl lactate + γ-butyrolactone Propylene glycol monomethyl ether acetate + 3-ethoxyethyl propionate + γ-butyrolactone Propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + ethylene carbonate Propylene glycol monomethyl ether acetate + ethyl lactate + ethylene carbonate Propylene glycol monomethyl ether acetate + 3 -Ethoxyethyl propionate + ethylene carbonate propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + propylene carbonate propylene glycol monomethyl ether acetate + ethyl lactate + propylene carbonate propylene glycol monomethyl ether Acetate + 3-ethoxyethylpropionate + propylene carbonate propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + cyclohexanone.

Particularly preferred solvent combinations include:
Propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether Propylene glycol monomethyl ether acetate + cyclohexanone Propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + γ-butyrolactone Propylene glycol monomethyl ether acetate + ethyl lactate + γ-butyrolactone Propylene glycol monomethyl ether acetate + 3-ethoxyethyl Propionate + γ-butyrolactone Propylene glycol monomethyl ether acetate + Propylene glycol monomethyl ether + Ethylene carbonate Propylene glycol monomethyl ether acetate + Ethyl lactate + Ethylene carbonate Propylene glycol monomethyl Ether ether + 3-ethoxyethyl propionate + ethylene carbonate propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + propylene carbonate propylene glycol monomethyl ether acetate + ethyl lactate + propylene carbonate propylene glycol monomethyl ether acetate + 3-ethoxyethyl propionate + propylene Carbonate propylene glycol monomethyl ether acetate + propylene glycol monomethyl ether + cyclohexanone.

  Each of the above mixed solvents may be added with other solvents. Generally the addition amount of such other solvent is 30 mass parts or less with respect to 100 mass parts of each mixed solvent of this invention. Examples of other solvents include ethylene dichloride, cyclopentanone, methyl ethyl ketone, toluene, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like.

  The positive resist composition of the present invention preferably uses the above-mentioned mixed solvent, but if necessary, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclohexanone, etc. can be used as a single solvent.

The positive resist composition of the present invention has a low molecular acid decomposability, which has a molecular weight of 2000 or less, if necessary, has a group that can be decomposed by the action of an acid, and has increased alkali solubility by the action of an acid. Compounds can be included.
For example, described in Proc. 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 compounds described in JP-A-6-51519 can also be used in an addition range at a level that does not deteriorate the transmittance at 220 nm, and 1,2-naphthoquinone diazite compounds 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.

  If necessary, the positive resist composition of the present invention may further contain a compound that promotes dissolution in a developer, an antihalation agent, a plasticizer, a surfactant, a photosensitizer, an adhesion assistant, a crosslinking agent, and a photobase. A generator or the like can be contained.

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.

  A photosensitizer can be added to improve the acid generation rate by exposure. 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.

≪How to use≫
The positive resist composition of the present invention is used by dissolving the above-described components in a solvent, filtering with a filter, and coating on a predetermined support as follows.
That is, the 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 a coater, and heated to form a resist. A film is formed.
Next, exposure is performed through a predetermined mask, and development is performed by heating. In this way, a good resist pattern can be obtained. Here, the exposure light is preferably far ultraviolet rays having a wavelength of 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 F2 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 of cyclic amines such as quaternary ammonium salts 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 of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

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

Synthesis Example (1) Synthesis of Resin (1) 2-Ethyl-2-adamantyl methacrylate and butyrolactone methacrylate were charged at a ratio of 55/45 (molar ratio) and dissolved in methyl ethyl ketone / tetrahydrofuran = 5/5, and the solid content concentration was 20 mass. 100 mL of a% solution was prepared. To this solution, 2 mol% of a polymerization initiator V-65 manufactured by Wako Pure Chemical Industries, Ltd. was added and added dropwise to 10 mL of methyl ethyl ketone heated to 60 ° C. over 4 hours in a nitrogen atmosphere.
After completion of the dropwise addition, the reaction solution was heated for 4 hours, 1 mol% of V-65 was added again, and the mixture was stirred for 4 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and the resin (1) which was a white powder crystallized and precipitated in 3 L of a mixed solvent of distilled water / ISO propyl alcohol = 1/1 (mass ratio) was recovered.
The polymer composition ratio determined from C ¹³ NMR was 46/54. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 10700.

Resins (2) to (12) were synthesized by the same operation as in Synthesis Example (1).
The composition ratios and molecular weights of the resins (2) to (10) are shown below. (Repeating units 1, 2, 3, and 4 are the order from the left of the structural formula.)

  Hereinafter, the structure of resin (1)-(10) is shown.

  Hereinafter, the structure, composition ratio, and weight average molecular weight of the resin (11) are shown.

  Resin (12) is as follows.

Examples 1-14 and Comparative Examples 1-6
(Preparation and evaluation of positive resist composition)
1.03 g of resin,
0.00035 mol of acid generator,
(C) 16.5 mg of the component compound,
Nitrogen-containing basic compound 1.65mg and surfactant 100ppm in total
Were dissolved in the solvents shown in Tables 2 and 3 so that the solid content was 11% by mass, respectively, and then filtered through a 0.1 μm microfilter, and Examples 1 to 14 were obtained. And positive resist compositions of Comparative Examples 1 to 6 were prepared.

As a nitrogen-containing basic compound,
N-1: 1,5-diazabicyclo [4.3.0] -5-nonene N-2: 1,8-diazabicyclo [5.4.0] -7-undecene N-3: 4-dimethylaminopyridine N -4: triphenylimidazole N-5: diisopropylaniline N-6: tributylamine N-7: trioctylamine

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

As a solvent,
S-1: Propylene glycol monomethyl ether acetate S-2: Ethyl lactate S-3: Butyl acetate S-4: 2-Heptanone S-5: Propylene glycol monomethyl ether S-6: Ethyl ethoxypropionate S-7: γ- Butyrolactone S-8: ethylene carbonate S-9: propylene carbonate S-10: represents cyclohexanone.

(1) Profile evaluation An antireflection film DUV-42 manufactured by Brewer Science Co., Ltd. was uniformly applied to 600 Å on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, and dried on a hot plate at 100 ° C. for 90 seconds. Then, it heat-dried at 190 degreeC for 240 second. Thereafter, each positive resist composition was applied with a spin coater and dried at 120 ° C. for 90 seconds to form a 0.30 μm resist film.
This resist film was exposed with an ArF excimer laser stepper (NA = 0.60 0.60 / 0.80 annular zone manufactured by ISI) through a mask, and immediately after exposure, heated on a hot plate at 120 ° C. for 90 seconds. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds and then dried to obtain a line pattern.
A profile of a 0.13 μm 1/1 line and space line was observed with a scanning microscope, and a rectangular profile was evaluated as ◯, a slightly round-top profile was evaluated as Δ, and a round-top profile was evaluated as ×.

(2) Evaluation of sensitivity and resolving power Sensitivity was expressed by an exposure amount for reproducing a 0.13 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.

(3) Line edge roughness evaluation There should be an edge in the range of 5 μm in the longitudinal direction of the 0.13 μm line pattern obtained by the minimum exposure amount that reproduces the 0.13 μm line and space (1/1) pattern. The distance from the reference line was measured at 50 points using a length-measuring scanning electron microscope (S-8840, manufactured by Hitachi, Ltd.), the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance.

(4) Pattern collapse suppression evaluation Continuous 15 line and space 1: 1 mask patterns were evaluated (exposure conditions were the same as the profile evaluation method). When the line width is measured from the exposure amount that reproduces the 0.13 μm line and space 1: 1 mask pattern, and the exposure amount is changed, the pattern collapses when at least one of the five in the center falls. The starting point. The line width immediately before the pattern collapse start point (the limit in which the middle five lines remain unfallen) was expressed as the limit line width of pattern collapse.

(5) Evaluation of PED stability Radiation dose (for example, ArF excimer laser: 14 mJ) that can form a 0.13 μm line and space pattern as designed on a resist film formed by applying and baking a positive resist composition / Cm ² or EB: 10 μC / cm ² ), and the wafer subjected to the radiation irradiation process was left in a clean room for 2 hours. Subsequently, development was carried out following baking after irradiation, and a deviation from the design dimension of the 0.13 μm line and space pattern was measured.
｜ Design dimension-Actual dimension ｜ / Design dimension x 100 (%)
The smaller the value, the better.
The evaluation results are shown in Tables 2-3.

  From Tables 2 to 3, the positive resist composition of the present invention has suppressed pattern collapse when trying to resolve a fine pattern, and has improved PED stability, line edge roughness, profile, sensitivity, and resolution. It is clear that

Claims (6)

(A) a resin whose solubility 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,
(C) having at least one partial structure represented by the following general formula (I) or (II),
A positive resist composition comprising a nonionic cyclic compound satisfying at least one of a melting point of 35 ° C. or higher or a boiling point of 100 ° C./10 mmHg or higher and (D) a solvent.

  The nonionic cyclic compound of the component (C) has an alicyclic structure or a bridged alicyclic structure, and at least one ring constituting the alicyclic structure or the bridged alicyclic structure has the above general formula. 2. The positive resist composition according to claim 1, which has at least one partial structure represented by (I) or (II).   The positive resist composition according to claim 2, wherein the nonionic cyclic compound of component (C) has a bridged alicyclic structure and does not have a benzene ring.   The nonionic cyclic compound of component (C) has two or more partial structures represented by the above general formula (I) and does not have a benzene ring, and is represented by the above general formula (II) 4. The positive resist composition according to claim 1, wherein the positive resist composition is selected from compounds having at least one partial structure and having no benzene ring.   The positive resist composition according to claim 1, further comprising (E) a nitrogen-containing basic compound.   A pattern forming method comprising: forming a resist film from the positive resist composition according to claim 1; and exposing and developing the resist film.