JP2005077738A - Positive resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition for suppressing failure of a pattern, when resolving a minute pattern, and to provide a pattern forming method using it. <P>SOLUTION: In the positive resist composition and the pattern forming method which uses the composition, the positive resist composition contains a resist, in which an alicyclic hydrogen carbon group having (A) a resin with increasing dissolution speed with respect to an alkali developing liquid by the action of an acid, (B) a compound-generating acid by irradiation with active light or with radiation, and (C) a ketone group of 0.1-10 mass% substitutes for a side chain. <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. More specifically, the present invention relates to a positive resist composition suitable for using an ultraviolet ray 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 chemically amplified resist compositions, resins containing an alicyclic group having a carbonyl group have been studied in Patent Documents 1 to 4 and the like in order to improve adhesion and the like.
However, in any case, it has been desired to improve the performance in terms of pattern collapse when forming a fine pattern.

JP-A-8-305023 JP 10-115925 A Japanese Patent Laid-Open No. 11-84663 JP 2001-188351 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.

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

(1) (A) a resin whose dissolution rate in an alkaline developer is increased by the action of an acid;
(B) The compound which generate | occur | produces an acid by irradiation of actinic light or a radiation, and 0.1-10 mass% (C) The resin which the alicyclic hydrocarbon group which has a ketone group substituted by the side chain is contained. A positive resist composition characterized by the above.

Further preferred embodiments include the following configurations.
(2) The positive resist composition as described in (1), further comprising (E) a nitrogen-containing basic compound.

  (3) The positive resist composition as described in any one of (1) to (2), wherein the resin as the component (A) has an alicyclic structure or a bridged alicyclic structure.

  (4) The resin (A) is a resin having an alkali-soluble group protected by a 2-alkyl-2-adamantyl group or 1-adamantyl-1-alkylalkyl group. The positive resist composition as described.

  (5) The resin of component (A) is a resin having a repeating unit having a group represented by any one of the following general formulas (V-1) to (V-5) ( The positive resist composition as described in 3) or (4).

In General Formulas (V-1) to (V-5), R _{1b to} R _6b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, or —COOR _7b . R _7b represents an alkyl group. Two of R _{1b to} R _6b may combine to form a ring.

(6) The positive resist composition as described in any one of (3) to (5), wherein at least one of the bridged alicyclic structures of the resin as the component (A) is dihydroxyadamantane.
(7) A pattern forming method comprising: forming a resist film from the resist composition according to any one of (1) to (6) above; and exposing and developing the resist film.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a positive resist composition improved by suppressing pattern collapse when attempting to resolve a fine pattern, and a pattern forming method thereof.

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 dissolution rate in an alkaline developer is increased by the action of an acid The positive resist composition of the present invention is a resin (hereinafter referred to as “the dissolution rate in an alkaline developer” due to the action of an acid). Also referred to as “acid-decomposable resin”.
When the positive resist composition of the present invention is irradiated with ArF excimer laser light, the acid-decomposable resin preferably has an alicyclic structure or a bridged alicyclic structure.
For example, a resin having a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI) is preferable.

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 an alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{12 to} R ₁₄ , or R ₁₅ , R ₁₆ Either represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ is alicyclic carbonized. Represents a hydrogen group. In addition, either R ₁₉ or R ₂₁ represents an alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{22 to} R ₂₅ is alicyclic carbonized. Represents a hydrogen group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In general formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ may have a substituent, and represents a linear or branched alkyl group having 1 to 4 carbon atoms. . 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.
In addition, examples of the substituent that the alkyl 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), an acyl group, an acyloxy group, and a cyano group. Group, hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

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 substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

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 an 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, alkoxymethyl group such as 1-toxylmethyl group and 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3-oxo Examples include a cyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue, and the like. 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.

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, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r ₁ is an integer of 1 to 10.

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,
Examples thereof include a t-butyl group.

Examples of the substituent that the alkyl group as Ra _{1 to} Re ₁ may have include a carboxyl group, an acyloxy group, a cyano group, a halogen atom, a hydroxyl group, an alkoxy group, a substituted alkoxy group, an acetylamide group, an alkoxycarbonyl group, An acyl group is mentioned.
Here, as an alkoxy group, C1-C4 things, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, can be mentioned. The alkoxy group may further have a substituent such as an alkoxy group.
Examples of the acyloxy group include an acetoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

  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.

  Moreover, you may contain the repeating unit which has group represented by either of the following general formula (V-1)-(V-5).

In General Formulas (V-1) to (V-5), R _{1b to} R _6b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, or —COOR _7b . R _7b represents an alkyl group. Two of R _{1b to} R _6b may combine to form a ring. In addition, that R _<1b > -R <_6b> is a hydrogen atom means that it is unsubstituted.

In the general formulas (V-1) to (V-5), examples of the alkyl group in R _{1b to} R _7b include linear and branched alkyl groups, which may have 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 < _6b >, 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 < _6b >, 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 _6b 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-5), R _{1b to} R _6b 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 (V-1) to (V-5) 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. As a preferable substituent that the alkyl group of R _b0 may have, as a preferable substituent that the alkyl group as R _1b in the general formulas (V-1) to (V-5) 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-5).
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, or an alkoxy group, and both may be the same or different.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms.
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. 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, an alkyl group or COOR _3a . R _3a represents an alkyl group.

The alkyl group as R _{1a to} R _3a 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 alkyl group as R _{1a to} R _3a 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, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r is an integer of 1-10.
In the general formula (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, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxypropyl acrylate, 5 -Hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, 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, 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-alkyl acrylamide (alkyl groups include those having 1 to 10 carbon atoms such as methyl, ethyl, propyl, butyl, t-butyl, heptyl, octyl, and hydroxyethyl groups. ), N, N-dialkylacrylamide (alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, butyl, isobutyl, and ethylhexyl groups), N-hydroxyethyl-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, etc.), N, N-dialkylmethacryl Amides (there are alkyl groups such as ethyl, propyl and butyl groups), 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 acid-decomposable resin preferably does not have an aromatic group from the viewpoint of transparency to ArF light.
Further, the acid-decomposable resin preferably does not have a ketone group that the resin of component (C) has.

  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 acid-decomposable resin used in the present invention can be synthesized according to a conventional method (eg, 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 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.
Moreover, the acid-decomposable resin may be used alone or in combination.

The mass average molecular weight of the acid-decomposable resin 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 (photoacid generator)
Examples of the compound (photoacid generator) that generates an acid upon irradiation with actinic rays or radiation used in the present invention include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, and a photodecolorant for dyes. , Known light (400-200 nm ultraviolet light, far ultraviolet light, particularly preferably g-line, h-line, i-line, KrF excimer laser light), ArF excimer laser light used for photochromic agents or microresists A compound capable of generating an acid upon generation of an acid upon irradiation with an actinic ray or radiation such as an electron beam, an X-ray, a molecular beam or an ion beam and a mixture thereof can be appropriately selected and used.

Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.
Particularly preferred are sulfonium salts, and triarylsulfonium salts, phenacylsulfonium salts, and sulfonium salts having a 2-oxoalkyl group are most preferred.

  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, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light as described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that can be used in combination with an active ray or radiation to generate an acid upon decomposition, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) are exemplified. Can do.

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion.

Examples of the non-nucleophilic anion of X ⁻ include a sulfonate anion, a carboxylate anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.
A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.
Examples of the sulfonate anion include an alkyl sulfonate anion, a cycloalkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion.
Examples of the carboxylate anion include an alkylcarboxylate anion, an arylcarboxylate anion, and an aralkylcarboxylate anion.

The alkyl group in the alkylsulfonate anion is preferably an alkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a 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 in the cycloalkyl sulfonate anion 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 the aryl sulfonate anion is preferably an aryl group 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 alkyl sulfonate anion, cycloalkyl sulfonate anion and aryl 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 alkyl group in the alkylcarboxylate anion include the same alkyl groups as in the alkylsulfonate anion.
Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate 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 alkyl group, aryl group and aralkyl group in the alkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent are the same as those in the arylsulfonate anion. A halogen atom, an alkyl group, an alkoxy group, an alkylthio group, etc. can be mentioned.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. These alkyl groups may have a substituent, and examples of the substituent include a halogen atom, an alkoxy group, and an alkylthio group.

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

As the non-nucleophilic anion of X ⁻ , an alkanesulfonic acid anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an arylsulfonic acid anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group having a fluorine atom A bis (alkylsulfonyl) imide anion substituted with a tris (alkylsulfonyl) methide anion substituted with a fluorine atom in the alkyl group, particularly preferably a perfluoroalkanesulfonic acid anion having 1 to 8 carbon atoms, most preferably Nonafluorobutane sulfonate anion and perfluorooctane sulfonate anion.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  More preferable (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-1) is a triarylsulfonium compound in which each of R _{201 to} R _{203 in} the general formula (ZI) is an aryl group, that is, a compound 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 may have an alkyl group (for example, 1 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group as a substituent. Preferred substituents are linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl groups having 1 to 4 carbon atoms, 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.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group containing no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, most preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl group, Butyl group, pentyl group).
The cycloalkyl group as R _{201 to} R ₂₀₃ is preferably a cyclic alkyl group having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group, norbornyl group).

More preferably, it is a 2-oxoalkyl group or an alkoxycarbonylmethyl group, and the 2-oxoalkyl group may be linear, branched or cyclic, and preferably at the 2-position of the above alkyl group> Mention may be made of groups having C═O.
Further, the alkoxy group in the alkoxycarbonylmethyl group is preferably an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

  The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
Any two or more of R _1c to R _7c, and Rx and Ry may combine with each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond You may go out.
Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ⁻ in formula (ZI) or (ZII).

The alkyl group as R _{1c to} R _{5c may} be either linear or branched, for example, an alkyl group having 1 to 10 carbon atoms, preferably a linear or branched alkyl group having 1 to 5 carbon atoms (for example, Methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).
The cycloalkyl group as R _{1c to} R _5c is preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group or a cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably either a straight chain of R _1c to R _5c, branched, cyclic alkyl group, or a linear, branched or cyclic alkoxy group, more preferably the sum of the carbon atoms of R _5c from R _1c 2 to 15 It is. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _6c and R _7c include the same alkyl groups and cycloalkyl groups as R _{1c to} R _5c . As an aryl group, a C6-C14 aryl group (for example, phenyl group) can be mentioned, for example.
Alkyl group and cycloalkyl group as Rx and Ry may be the same as the alkyl group and cycloalkyl group as R _1c to R _5c.

A 2-oxoalkyl group and an alkoxycarbonylmethyl group are preferable,
Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group as R _{1c to} R _5c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
Examples of the group formed by combining Rx and Ry include a butylene group and a pentylene group.

In formula (ZII) and (ZIII), R ₂₀₄ ~R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R _{204 to} R ₂₀₇ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, Butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cyclic alkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g. having 6 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms ), Halogen atoms, hydroxyl groups, phenylthio groups, and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ⁻ in formula (ZI) or (ZII).

  Examples of particularly preferable compounds among the compounds that are decomposed by irradiation with actinic rays or radiation that may be used in combination are listed below.

  The addition amount of the photoacid generator is usually used in the range of 0.001 to 30% by mass, preferably 0.3 to 20% by mass, more preferably 0.5 to 0.5%, based on the solid content in the composition. It is used in the range of 10% by mass. That is, the addition amount of the photoacid generator is preferably 0.001% by mass or more in terms of sensitivity, and 30% by mass or less in terms of good light absorption, good profile, and process (especially baking) margin of the resist. preferable.

[3] (C) Resin having an alicyclic hydrocarbon group having a ketone group in the side chain The resist composition of the present invention is a resin (added resin C) having an alicyclic hydrocarbon group having a ketone group in the side chain. ).
In the present invention, an alicyclic hydrocarbon group having a ketone group refers to a ketone group in which an oxygen atom (= O) is bonded to the middle carbon atom of three consecutive carbon atoms constituting the alicyclic skeleton. It means an alicyclic hydrocarbon group that is formed. Hereinafter, such a ketone group is also referred to as an alicyclic ketone group.

The alicyclic skeleton of the alicyclic hydrocarbon group 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 5 to 30, and particularly preferably 6 to 25.
For example, the following can be mentioned.

The number of alicyclic ketone groups in the repeating unit having an alicyclic hydrocarbon group having a ketone group is preferably 1 to 5, more preferably 1 to 3. In the repeating unit, one alicyclic hydrocarbon group may have a plurality of alicyclic ketone groups, or a plurality of alicyclic hydrocarbon groups having an alicyclic ketone group may exist.
The alicyclic skeleton may have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and an isopropyl group), a halogen atom, a hydroxyl group, and an alkoxy group (preferably having 1 to 5 carbon atoms, such as a methoxy group). Ethoxy group, propoxy group, butoxy group), carboxyl group, alkoxycarbonyl group (preferably having 2 to 6 carbon atoms, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group). These substituents may be further substituted with a hydroxyl group, a halogen atom, an alkoxy group or the like.

  Although the repeating unit which has an alicyclic hydrocarbon group which has a ketone group in a side chain is not specifically limited, For example, a (meth) acrylic acid repeating unit can be mentioned.

  Although the specific example of the repeating unit which has an alicyclic hydrocarbon group which has a ketone group below is given, it is not limited to these.

The additive resin C can contain other repeating units other than the repeating unit having an alicyclic hydrocarbon group having a ketone group in the side chain.
As the other repeating unit, any repeating unit may be used, and examples thereof include the repeating units mentioned in the resin of component (A).

  The content of the repeating unit having an alicyclic hydrocarbon group having a ketone group in the additive resin C in the side chain is usually 10 mol% or more, preferably 25 mol% or more, more preferably, based on all repeating units. It is 40 mol% or more.

  The additive resin C can be obtained by polymerizing a monomer having an alicyclic hydrocarbon group having a ketone group in the side chain, if necessary, together with other monomers as in the synthesis of the resin of component A. it can.

  The mass average molecular weight of the additive resin C is usually 1000 to 100,000, preferably 2000 to 50,000.

  The addition amount of the additive resin C is 0.1 to 10% by mass, preferably 0.2 to 5% by mass, and more preferably 0.5 to 2.5% by mass with respect to the total solid content of the composition.

[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 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-8110638, JP-A8-123030, 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.

As the nitrogen-containing basic compound, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo is preferable. [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 63-3345, 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. 5,436,098, 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).
For example, as a commercially available surfactant, Megafac F178, F-470,
F-473, F-475, F-476, F-472 (Dainippon Ink Chemical Co., Ltd. product) can be mentioned. 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 usage-amount of surfactant is 0.0001-2 mass% with respect to positive resist composition whole quantity (except a solvent), More preferably, it is 0.001-1 mass%.

[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. As other solvents, in addition to the solvents exemplified as the essential solvents for each of the above mixed solvents, ethylene dichloride, cyclopentanone, methyl ethyl ketone, toluene, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like Can be mentioned.

  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. 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 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 accelerating compound that can be used in the present invention include a compound 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.

≪How to use≫
The positive resist composition of the present invention is used for pattern formation by dissolving the above components in a solvent and usually filtering with a filter.
As a preferred pattern formation method, the positive resist composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device by an appropriate application method such as a spinner or a coater. Then, a resist film is formed by heating. Next, the resist film is exposed through a predetermined mask, heated and developed. Thereby, 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 alkaline developer used for development include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, 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 and the like Alkaline aqueous solutions such as quaternary ammonium salts, 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 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), propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 7/3 (mass) Ratio) to prepare 100 mL of a solution having a solid content of 20% by mass. 1 mol% of Wako Pure Chemical Industries polymerization initiator V-601 was added to this solution, and this was dripped at 10 mL of methyl ethyl ketone heated at 60 degreeC over 6 hours in nitrogen atmosphere. After completion of dropping, the reaction solution was heated for 4 hours and 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 2 L of heptane was recovered.
The polymer composition ratio (molar ratio) determined from C ¹³ NMR was 46/54. Moreover, the standard polystyrene conversion mass mean molecular weight 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.

  The structures, composition ratios, and mass average molecular weights of the resins (11) and (12) are shown.

Synthesis Example (2) Synthesis of Additive Resin (C1) 4-Oxoadamantyl methacrylate and methacrylic acid were charged at a ratio of 70/30 (molar ratio), and propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 70/30 (mass ratio) 450 g of a solution having a solid content concentration of 22% was prepared. To this solution, 2 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added, and this was heated to 100 ° C. over 6 hours under a nitrogen atmosphere. Propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 70/30 (mass Ratio) 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 solution of hexane / ethyl acetate = 9/1 (mass ratio), and the precipitated white solid was collected by filtration to obtain the target resin (C1). It was collected.
^The polymer composition ratio (4-oxoadamantyl methacrylate / methacrylic acid) determined from ¹³ CNMR and polymer acid value measurement was 68/32 (molar ratio). Further, the mass average molecular weight in terms of standard polystyrene determined by GPC measurement was 6700, and the degree of dispersion was 1.8.
Hereinafter, resins (C2) to (C10) having the following repeating units were synthesized by the same method as in Synthesis Example (2).
Table 2 shows the ratio of repeating units, mass average molecular weight, and degree of dispersion.

[Examples 1 to 14 and Comparative Example 1]
(Preparation and evaluation of positive resist composition)
Resin 2g,
Acid generator (addition amount described in Table 3)
Additive resin C (addition amount described in Table 3)
5mg of basic compound and 100ppm of surfactant in resist solution
Were dissolved in the solvent shown in Table 3 so that the solid content was 10% by mass, respectively, and then filtered through a 0.1 μm microfilter (made of polyethylene). A positive resist composition of Comparative Example 1 was prepared.

[Pattern collapse suppression evaluation]
An antireflective film ARC-29A manufactured by Brewer Science Co., Ltd. was uniformly applied to a silicon substrate that had been subjected to hexamethyldisilazane treatment with a spin coater, dried at 100 ° C. for 90 seconds on a hot plate, and then heated at 205 ° C. for 240 seconds. Heat drying was performed for 2 seconds. Thereafter, each positive resist composition was applied by a spin coater and dried at a PB temperature shown in Table 3 for 90 seconds to form a 360 nm resist film.
This resist film was exposed with an ArF excimer laser stepper (PAS5500 / 1100, manufactured by ASML, NA = 0.75 (σ = 0.80 / 0.50)) through a mask, and immediately after the exposure, the PEB temperature shown in Table 3 was used. The film was heated on a hot plate for 90 seconds, further developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 30 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a line pattern.

Measure the minimum line width (in nm) that remains without falling over when the exposure amount reproduced by a 120 nm line pattern (pitch 280 nm) is the optimal exposure amount (Eopt) and the exposure amount is over (approximately 5 to 15%). The length was measured using a long SEM (S-9260, manufactured by Hitachi High-Technology Corporation). The pattern collapse is better when the line pattern remains to a thinner line width.
The evaluation results are shown in Table 3.

  The symbols for each component in Table 3 are as follows. The photoacid generator is exemplified above.

[Nitrogen-containing basic compound]
N1: N, N-dibutylaniline N2: triethanolamine N3: 4-dimethylaminopyridine N4: triphenylimidazole N5: 2,6-diisopropylaniline N6: hydroxyantipyrine N7: trioctylamine

[Surfactant]
W1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
W4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
Represents.

〔solvent〕
S1: Propylene glycol monomethyl ether acetate S2: Ethyl lactate S3: Butyl acetate S4: 2-Heptanone S5: Propylene glycol monomethyl ether S6: γ-butyrolactone S7: Propylene carbonate S8: Cyclohexanone

From Table 3, it is clear that the positive resist composition of the present invention is improved by suppressing pattern collapse when attempting to resolve a fine pattern.

Claims (2)

(A) a resin whose dissolution rate in an alkaline developer is increased by the action of an acid;
(B) The compound which generate | occur | produces an acid by irradiation of actinic light or a radiation, and 0.1-10 mass% (C) The resin which the alicyclic hydrocarbon group which has a ketone group substituted by the side chain is contained. A positive resist composition characterized by the above. A pattern forming method comprising: forming a resist film from the resist composition according to claim 1; and exposing and developing the resist film.