JP2010072232A - Positive resist composition and pattern formation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition which has high sensitivity and no substrate dependence and which provides excelling profile shape, even when a basic substrate is used, and to provide a pattern forming method that uses the positive resist composition. <P>SOLUTION: The positive resist composition includes a compound (N) having a nitro group and an acid radical, and the pattern forming method using the positive resist composition is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

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 use as an exposure light source such as far ultraviolet rays of 220 nm or less and an irradiation source using an electron beam, and a pattern forming method using the same.

Since chemically amplified resists utilize the action of acid, when the substrate is basic, the problem is that the acid is deactivated and the profile becomes a trailing shape (hereinafter referred to as substrate dependency). is there. When using a basic substrate such as SiN (silicon nitride film) or SiON, a substrate provided with an insulating film such as BPSG (boron-phosphorus-silicate glass) or a film of TiN (titanium nitride), these films are formed. In this case, there is a problem that a basic component remains in the vicinity of the substrate, resulting in a trailing pattern shape.
In order to solve these problems, it is known that a large amount of a basic quencher component may be added. However, if a large amount of quencher component is added, the sensitivity of the resist decreases.
Further, as a method for solving these problems, there is a method of providing a film such as an antireflection layer between the substrate and the resist film. However, this method increases the number of manufacturing steps and decreases the throughput, and the cost is high. Therefore, it is not preferable.
Therefore, there is a demand for a resist that can form a resist pattern having no substrate dependency and having an excellent profile shape.
In Patent Documents 1 to 3, an acid generator having a specific structure is used. Further, Patent Document 4 uses a specific basic compound, Patent Document 5 uses a hydroxycarboxylic acid ester compound, and Patent Document 5 uses a specific additive, but further improvements have been demanded.

JP 2005-134923 A Japanese Patent Laid-Open No. 2004-70366 JP 2003-177540 A JP 2000-66382 A JP 2001-174982 A JP 11-44950 A

  An object of the present invention is to provide a positive resist composition having a high profile, having no substrate dependency, and having an excellent profile shape even when a resist film is directly formed on a basic substrate without providing an antireflection film or the like. The object is to provide a pattern forming method using a positive resist composition.

As a result of intensive studies, the present inventor has reached the present invention.
The present invention has the following configuration.

(1)
A positive resist composition comprising a compound (N) having at least one nitro group and one acid group.
(2)
The positive resist composition as described in (1) above, wherein the acid group of the compound (N) is a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group or a boronic acid group.
(3)
The positive resist composition as described in (1) above, wherein the acid group of the compound (N) is a carboxylic acid group or a sulfonic acid group.
(4)
The positive resist composition as described in any one of (1) to (3) above, wherein the compound (N) contains at least one aromatic ring.
(5)
The positive resist composition as described in (4) above, wherein the compound (N) has a structure in which a nitro group or an acid group is directly bonded to an aromatic ring.
(6)
Furthermore, (A) a resin whose solubility in an alkaline developer is increased by the action of an acid, and (B) a compound that generates an acid upon irradiation with actinic rays or radiation, (1) to (1) above The positive resist composition according to any one of (5).

(7)
(A) A resin whose solubility in an alkali developer increases by the action of an acid contains at least one repeating unit represented by the general formula (A1) or (A2). The positive resist composition according to any one of (6).

In general formula (A1),
n shows the integer of 0-5. m shows the integer of 0-5. However, m + n ≦ 5.
A ₁ represents a hydrogen atom or a group containing a group that decomposes under the action of an acid, and when there are a plurality of groups, they may be the same or different.
S ₁ represents an arbitrary substituent, and when there are a plurality of S _{1 s} , they may be the same or different.
In general formula (A2),
X is a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyloxy group or aralkyl. Represents a group.
A ₂ represents a group containing a group that decomposes by the action of an acid.
(8)
(B) The positive resist composition as described in any one of (1) to (7) above, wherein the compound that generates an acid upon irradiation with actinic rays or radiation is oxime sulfonate or diazodisulfone.
(9)
Furthermore, it contains a compound that has a proton acceptor functional group and generates a compound that is decomposed by irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. The positive resist composition as described in any one of (1) to (8) above.

The preferred embodiments of the present invention will be further described below.
(10)
The positive resist composition as described in any one of (1) to (9) above, wherein the molecular weight of the compound (N) is 2,000 or less.
(11)
The positive resist composition as described in any one of (1) to (9) above, wherein the compound (N) has a molecular weight of 1,000 or less.
(12)
The positive resist composition according to any one of (1) to (9) above, wherein the compound (N) has a molecular weight of 500 or less.

(13)
The positive resist composition as described in any one of (1) to (12) above, further comprising (C) an organic basic compound.

(14)
Furthermore, (D) surfactant is contained, The positive resist composition in any one of said (1)-(13) characterized by the above-mentioned.

(15)
The positive resist composition as described in any one of (1) to (14) above, further comprising a solvent.

(16)
The positive resist composition as described in any one of (1) to (15) above, which contains propylene glycol monomethyl ether acetate as a solvent.

(17)
The positive resist composition as described in any one of (1) to (16) above, which contains propylene glycol monomethyl ether as a solvent.

(18)
The positive resist composition as described in any one of (1) to (17) above, which is exposed by irradiation with KrF, electron beam, X-ray or EUV.

(19)
A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of the above (1) to (18), exposing and developing the resist film.

(20)
The pattern forming method as described in (19) above, wherein the resist film is formed on a basic substrate.

  The present invention provides a positive resist composition that is highly sensitive, has no substrate dependency, and has an excellent profile shape even when a basic substrate is used, and a pattern forming method using the positive resist composition. Can do.

Hereinafter, the best mode for carrying out the present invention will be described.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

(N) Compound having at least one nitro group and acid group The positive resist composition of the present invention contains a compound (N) having at least one nitro group and one acid group.

The acid group of the compound (N) is preferably a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group or a boronic acid group. More preferably, it is a carboxylic acid group or a sulfonic acid group.
The compound (N) preferably contains at least one aromatic ring. Here, examples of the aromatic ring include a benzene ring, a naphthalene ring, and an anthracene ring, and a benzene ring is preferable.
In the compound (N), a nitro group or an acid group is preferably directly connected to the aromatic ring.
A plurality of nitro groups and acid groups may be independently present.
The molecular weight (Mw) of the compound (N) is preferably 3,000 or less, more preferably 2,000 or less, still more preferably 1,000 or less, and most preferably 500 or less.

  A plurality of nitro groups and acid groups may be contained in the compound (N), but preferably 1 to 4 each, more preferably 1 to 2 and most preferably 1 each.

The addition amount of the compound having at least one nitro group and one acid group to the positive resist composition is preferably 0.001 to 20% by mass, more preferably the total solid content of the positive resist composition as a total amount. It is 0.01-10 mass%, More preferably, it is 0.05-5 mass%, Most preferably, it is 0.05-1 mass%.
Further, one type of compound having at least one nitro group and one acid group may be used, or two or more types may be used in combination.

The compound (N) having a nitro group and an acid group can be synthesized by a known method based on a commercially available compound.
For example, a compound such as (N-1-21) can be purchased from Tokyo Chemical Industry Co., Ltd. or Aldrich.
Moreover, a nitro group can be introduce | transduced by a general reaction, for example, can be introduce | transduced by oxidizing a primary amine or an oxime. A compound containing a nitro group directly bonded to an aromatic ring can be synthesized under nitric acid or concentrated nitric acid conditions under sulfuric acid conditions.
As a method for introducing an acid group, for example, a carboxylic acid group can be introduced by oxidation of alcohol or aldehyde, hydrolysis of ester, amide, nitrile, acid anhydride or acid halide. The sulfonic acid group can be introduced by oxidation of thiol, disulfide, or sulfinic acid.
In addition, general methods described in precision organic synthesis (Nan-Edo) and experimental chemistry course (Maruzen Co., Ltd.) can also be used.

  Specific examples of the compound (N) having a nitro group and an acid group are shown below, but the present invention is not limited to these.

(A) Resin whose solubility in an alkaline developer is increased by the action of an acid The resist composition of the present invention contains a resin (A) whose solubility in an alkaline developer is increased by the action of an acid.
The resin (A) is preferably insoluble or hardly soluble in an alkali developer.
The resin (A) preferably has a repeating unit having a group (hereinafter, also referred to as “acid-decomposable group”) that generates a group that is decomposed by the action of an acid to increase the solubility in an alkali developer.
Examples of the acid-decomposable group include a group in which a hydrogen atom of an alkali-soluble group such as a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, or a thiol group is protected with a group capable of leaving by the action of an acid. .
Examples of the group capable of leaving by the action of an acid include —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), —C (═O) — _{O-C (R 36) (} R 37) (R 38), - C (R 01) (R 02) (OR 39), - C (R 01) (R 02) -C (= O) -O- C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ) and the like can be mentioned.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
Examples of the repeating unit having an acid-decomposable group include a repeating unit represented by the following general formula (A1) or (A2).
Further, an acid-decomposable group may be introduced by reacting a vinyl ether compound with a resin having no repeating unit having an acid-decomposable group.

  The resin (A) preferably contains a repeating unit represented by the general formula (A1) or (A2).

In general formula (A1),
n shows the integer of 0-5. m shows the integer of 0-5. However, m + n ≦ 5.
A ₁ represents a hydrogen atom or a group containing a group that decomposes under the action of an acid.

Examples of the acid-decomposable group include tertiary alkyl groups such as t-butyl group and t-amyl group, t-butoxycarbonyl group, t-butoxycarbonylmethyl group, —C (L ₁ ) (L ₂ ) —O—Z. An acetal group as represented by ² is preferred.
L ₁ and L ₂ may be the same or different and each represents an atom or group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl group.
Z ² represents an alkyl group, a cycloalkyl group or an aralkyl group.
Z ² and L ₁ may be bonded to each other to form a 5- or 6-membered ring.

Examples of the aralkyl group in L ₁ , L ₂ and Z ² include those having 7 to 15 carbon atoms such as benzyl group and phenethyl group. These groups may have a substituent.

Preferable substituents that the aralkyl group has include an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acylamino group, a sulfonylamino group, an alkylthio group, an arylthio group, an aralkylthio group, and the like. Examples of the aralkyl group having a substituent include an alkoxybenzyl group, a hydroxybenzyl group, and a phenylthiophenethyl group.
The range of the number of carbon atoms of the substituent which the aralkyl group in L ₁ , L ₂ and Z ² may have is preferably 12 or less.

Examples of the 5- or 6-membered ring formed by combining Z ² and L ₁ with each other include a tetrahydropyran ring and a tetrahydrofuran ring.

In the present invention, Z ² is preferably a linear or branched alkyl group. Thereby, the effect of the present invention becomes more remarkable.

When there are a plurality of S _{1 s,} each independently represents an arbitrary substituent, for example, an alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, aralkyl group, aralkyloxy group, hydroxy group, halogen atom , A cyano group, a nitro group, a sulfonylamino group, an alkylthio group, an arylthio group, and an aralkylthio group.
For example, as an alkyl group and a cycloalkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, an octyl group, A linear or branched alkyl group having 1 to 20 carbon atoms such as a dodecyl group or a cycloalkyl group is preferable. These groups may further have a substituent.
Further preferred substituents that may be included are alkyl group, alkoxy group, hydroxyl group, halogen atom, nitro group, acyl group, acyloxy group, acylamino group, sulfonylamino group, alkylthio group, arylthio group, aralkylthio group, thiophenecarbonyloxy Group, a thiophenemethylcarbonyloxy group, a heterocyclic residue such as a pyrrolidone residue, and the like, and a substituent having 12 or less carbon atoms is preferable.

  Examples of the alkyl group having a substituent include a cyclohexylethyl group, an alkylcarbonyloxymethyl group, an alkylcarbonyloxyethyl group, a cycloalkylcarbonyloxymethyl group, a cycloalkylcarbonyloxyethyl group, an arylcarbonyloxyethyl group, and an aralkylcarbonyloxyethyl group. , Alkyloxymethyl group, cycloalkyloxymethyl group, aryloxymethyl group, aralkyloxymethyl group, alkyloxyethyl group, cycloalkyloxyethyl group, aryloxyethyl group, aralkyloxyethyl group, alkylthiomethyl group, cycloalkylthiomethyl Group, arylthiomethyl group, aralkylthiomethyl group, alkylthioethyl group, cycloalkylthioethyl group, arylthioethyl group, aralkyl Oechiru group, and the like.

  The alkyl group and cycloalkyl group in these groups are not particularly limited, and may further have a substituent such as the aforementioned alkyl group, cycloalkyl group, or alkoxy group.

  Examples of the alkylcarbonyloxyethyl group and cycloalkylcarbonyloxyethyl group include cyclohexylcarbonyloxyethyl group, t-butylcyclohexylcarbonyloxyethyl group, n-butylcyclohexylcarbonyloxyethyl group, and the like.

The aryl group is not particularly limited, but generally includes those having 6 to 14 carbon atoms such as a phenyl group, a xylyl group, a toluyl group, a cumenyl group, a naphthyl group, an anthracenyl group, and the above-mentioned alkyl groups and cycloalkyl groups. And may have a substituent such as an alkoxy group.
Examples of the aryloxyethyl group include a phenyloxyethyl group, a cyclohexylphenyloxyethyl group, and the like. These groups may further have a substituent.

Aralkyl is not particularly limited, and examples thereof include a benzyl group.
Examples of the aralkylcarbonyloxyethyl group include a benzylcarbonyloxyethyl group. These groups may further have a substituent.

  Although the specific example of the repeating unit represented by general formula (A1) below is given, it is not limited to these.

In formula (A2),
X is a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyloxy group, or Represents an aralkyl group. Preferably, a hydrogen atom or an alkyl group. Most preferably, it represents an alkyl group (methyl group).
A ₂ represents a group containing a group that decomposes by the action of an acid.

In general formula (A2), the alkyl group as X may have a substituent, and may be linear or branched. As a linear alkyl group, Preferably it is C1-C30, More preferably, it is 1-20, For example, a methyl group, an ethyl group, n-propyl group, n-butyl group, sec-butyl group, t-butyl Group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group and the like. As a branched alkyl group, Preferably it is C3-C30, More preferably, it is 3-20, for example, i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group, Examples include i-hexyl group, t-hexyl group, i-heptyl group, t-heptyl group, i-octyl group, t-octyl group, i-nonyl group, t-decanoyl group and the like.
The alkoxy group as X may have a substituent, for example, the above alkoxy group having 1 to 8 carbon atoms, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group. And a cyclohexyloxy group.
Examples of the halogen atom as X include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.
The acyl group as X may have a substituent, for example, an acyl group having 2 to 8 carbon atoms, specifically, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, a pivaloyl group. Preferred examples include benzoyl group.
The acyloxy group as X may have a substituent, and is preferably an acyloxy group having 2 to 8 carbon atoms. For example, an acetoxy group, a propionyloxy group, a butyllioxy group, a valeryloxy group, a pivaloyloxy group, hexanoyl An oxy group, an octanoyloxy group, a benzoyloxy group, etc. can be mentioned.
The cycloalkyl group as X may have a substituent, may be monocyclic, polycyclic, or bridged. For example, the cycloalkyl group may have a bridged structure. The monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. Examples of the polycyclic type include groups having a bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, Examples thereof include a camphanyl group, a dicyclopentyl group, an α-pinel group, a tricyclodecanyl group, a tetocyclododecyl group, and an androstanyl group. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
The aryl group as X may have a substituent, and preferably has 6 to 14 carbon atoms, and examples thereof include a phenyl group, a xylyl group, a toluyl group, a cumenyl group, a naphthyl group, and an anthracenyl group. .
The alkyloxycarbonyl group as X may have a substituent, and preferably has 2 to 8 carbon atoms, and examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, and a propoxycarbonyl group.
The alkylcarbonyloxy group as X may have a substituent, and preferably has 2 to 8 carbon atoms, and examples thereof include a methylcarbonyloxy group and an ethylcarbonyloxy group.
The aralkyl group as X may have a substituent and is preferably an aralkyl group having 7 to 16 carbon atoms, for example, a benzyl group.
Substituents that the alkyl group, alkoxy group, acyl group, cycloalkyl group, aryl group, alkyloxycarbonyl group, alkylcarbonyloxy group, aralkyl group as X may further have include a hydroxyl group, a fluorine atom, chlorine Atom, bromine atom, iodine atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyloxy group Or an aralkyl group etc. are mentioned.

A group containing a group that decomposes by the action of an acid contained in A ₂ is a group in which A ₂ is released, resulting in a carboxyl group in the repeating unit represented by formula (A2), that is, the acid-decomposable group itself. Or a group containing an acid-decomposable group, that is, a group capable of decomposing by the action of an acid and generating an alkali-soluble group such as a hydroxyl group or a carboxyl group at the residue bonded to the repeating unit. .

A ₂ is preferably a hydrocarbon group (preferably having a carbon number of 20 or less, more preferably 4 to 12), and a t-butyl group, a t-amyl group, or a hydrocarbon group having an alicyclic structure (for example, an alicyclic ring). The group itself and a group in which an alicyclic group is substituted on the alkyl group) are more preferable.
A ₂ is preferably a tertiary alkyl group or a tertiary cycloalkyl group.
The alicyclic structure may be monocyclic or polycyclic. Specific examples include monocyclo, bicyclo, tricyclo, and tetracyclo structures having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These hydrocarbon groups having an alicyclic structure may have a substituent.
Examples of alicyclic structures are shown below.

  In the present invention, the alicyclic structure is preferably a monovalent alicyclic group as an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, or a norbornyl group. And 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 that the alicyclic ring may have 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 the alkoxy group may have a further substituent. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.

  As the acid-decomposable group having an alicyclic structure, groups represented by the following general formula (pI) to general formula (pV) are preferable.

In the general formulas (pI) to (pV),
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 necessary atomic group.
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 (pV), the alkyl group in R _{12 to} R ₂₅ may be either substituted or unsubstituted, and a linear or branched alkyl group having 1 to 4 carbon atoms Represents. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
Further, the further substituent of the alkyl group includes an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

Examples of the alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom include those described above as the alicyclic structure.

  The repeating unit represented by the general formula (A2) is preferably a repeating unit represented by the general formula (A2a).

  In addition, it is also preferable that the repeating unit represented by the general formula (A2) is a repeating unit represented by the general formula (A2 ′).

In general formula (A2 ′),
AR represents an aryl group.
Rn represents an alkyl group, a cycloalkyl group or an aryl group.
AR and Rn may be bonded to each other to form a ring.
A represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an alkyloxycarbonyl group.

  The aryl group of AR is preferably a phenyl group, a naphthyl group, or an anthranyl group, and each may have one or more substituents. Preferred substituents include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl and the like. Is a linear or branched alkyl group having 1 to 20 carbon atoms, or an alkoxy group, a hydroxyl group, a halogen atom, an aryl group, a cyano group, a nitro group, an acyl group, an acyloxy group, an acylamino group, a sulfonylamino group, an alkylthio group, Examples include arylthio groups, aralkylthio groups, thiophenecarbonyloxy groups, thiophenemethylcarbonyloxy groups, heterocyclic residues such as pyrrolidone residues, etc., but linear or branched alkyl groups having 1 to 5 carbon atoms, or alkoxy groups Is preferable from the viewpoint of resolving power. More preferred is benzene, paramethylbenzene or paramethoxybenzene.

As the alkyl group in Rn, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, dodecyl group, etc. , Preferably a linear or branched alkyl group having 1 to 20 carbon atoms is used.
The cycloalkyl group in Rn is preferably a cycloalkyl group having 3 to 15 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecanoyl group, An adamantyl group, a norbornyl group, a boronyl group, etc. can be mentioned.
As the aryl group in Rn, those having 6 to 14 carbon atoms such as phenyl group, xylyl group, toluyl group, cumenyl group, naphthyl group, and anthracenyl group are preferable.
Preferred substituents that the above-mentioned group as Rn may have include alkoxy groups, hydroxyl groups, halogen atoms, nitro groups, acyl groups, acyloxy groups, acylamino groups, sulfonylamino groups, alkylthio groups, arylthio groups, Heterocyclic residues such as aralkylthio group, thiophenecarbonyloxy group, thiophenemethylcarbonyloxy group, pyrrolidone residue, etc. are mentioned, among them alkoxy group, hydroxyl group, halogen atom, nitro group, acyl group, acyloxy group, acylamino group, A sulfonylamino group is preferred.

Examples of the alkyl group in A include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, dodecyl group, etc. , Preferably a linear or branched alkyl group having 1 to 20 carbon atoms is used. These groups may have a substituent, and preferred substituents that may be included include an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acyloxy group, an acylamino group, a sulfonylamino group, an alkylthio group, Examples include arylthio groups, aralkylthio groups, thiophenecarbonyloxy groups, thiophenemethylcarbonyloxy groups, and heterocyclic residues such as pyrrolidone residues. Among them, CF ₃ groups, alkyloxycarbonylmethyl groups, alkylcarbonyloxymethyl groups, hydroxy groups, etc. A methyl group, an alkoxymethyl group and the like are preferable.
Examples of the halogen atom in A include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the alkyl contained in the alkyloxycarbonyl group in A include the same alkyl groups as in A above.

  Specific examples of the repeating unit represented by the general formula (A2) or a monomer corresponding thereto are given below, but the invention is not limited thereto.

  The monomer corresponding to the repeating unit represented by the general formula (A2) includes (meth) acrylic acid chloride and an alcohol compound in a solvent such as THF, acetone and methylene chloride, and a basic catalyst such as triethylamine, pyridine and DBU. It can be synthesized by esterification below. A commercially available product may be used.

  The resin (A) may further contain a repeating unit represented by the following general formula (A3).

In formula (A3),
X is a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyloxy group, or Represents an aralkyl group and is the same as X in formula (A2).
A _3a represents a hydrocarbon group that is not eliminated by the action of an acid.

In the general formula (A3), examples of the hydrocarbon group that is not eliminated by the action of an acid represented by A _3a include hydrocarbon groups other than the above-described acid-decomposable groups. A group (preferably having 1 to 15 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms) which is not eliminated by the action of an acid, an aryl group (preferably having 6 to 15 carbon atoms) which is not eliminated by the action of an acid, etc. Can be mentioned.

The hydrocarbon group which is not eliminated by the action of the acid of A _3a may be further substituted with a hydroxyl group, an alkyl group, a cycloalkyl group, an aryl group or the like.

  The resin (A) preferably further has a repeating unit represented by the general formula (A4).

In general formula (A4),
R ₂ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoro group having 1 to 4 carbon atoms.
R ₃ represents a hydrogen atom, an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
q represents an integer of 0 to 4.
W represents a group that is not decomposed by the action of an acid.

  W represents a group that is not decomposed by the action of an acid (also referred to as an acid-stable group), and examples thereof include hydrocarbon groups other than the above-mentioned acid-decomposable groups. Specific examples include hydrogen atoms, halogen atoms, alkyl groups, and cycloalkyl Group, alkenyl group, aryl group, acyl group, alkylamide group, arylamidomethyl group, arylamide group and the like. The acid stabilizing group is preferably an acyl group or an alkylamide group, more preferably an acyl group, an alkylcarbonyloxy group, an alkyloxy group, a cycloalkyloxy group, or an aryloxy group.

  In the acid stable group of W, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group and t-butyl group. As the alkyl group, those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferable, and as the alkenyl group, carbon number such as vinyl group, propenyl group, allyl group and butenyl group. Those having 2 to 4 carbon atoms are preferable, those having 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group are preferable as alkenyl groups, and phenyl group, xylyl group and toluyl group are preferable as aryl groups. And those having 6 to 14 carbon atoms such as cumenyl group, naphthyl group and anthracenyl group are preferable. W may be at any position on the benzene ring, but is preferably a meta position or a para position of the styrene skeleton, particularly preferably a para position.

  Although the specific example of the repeating unit represented by general formula (A4) below is given, it is not limited to these.

  The resin (A) preferably further has a repeating unit composed of a (meth) acrylic acid derivative that is not decomposed by the action of an acid. Although a specific example is given below, it is not limited to this.

  The content of the repeating unit having an acid-decomposable group in the resin (A) is preferably 5 to 95 mol%, more preferably 10 to 60 mol%, and particularly preferably 15 to 50 mol% in all repeating units. It is.

As for the content rate of the repeating unit represented by general formula (A1) in resin (A), 20-90 mol% is preferable in all the repeating units, More preferably, it is 30-80 mol%, Especially preferably, 40- 70 mol%.
The content of the repeating unit represented by the general formula (A2) in the resin (A) is preferably 0 to 90 mol%, more preferably 5 to 75 mol%, and particularly preferably 10 to 10 mol% in all repeating units. 60 mol%.

As for the content rate of the repeating unit represented by general formula (A3) in resin (A), 0-50 mol% is preferable in all the repeating units, More preferably, it is 0-40 mol%, Most preferably, it is 0-0. 30 mol%.
The resin (A) may further have a repeating unit represented by the general formula (A4), which is preferable from the viewpoints of improving the film quality and suppressing the decrease in film thickness of the unexposed area. The content of the repeating unit represented by the general formula (4) is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, and particularly preferably 0 to 40 mol% in each of all the repeating units. 30 mol%.

  The resin (A) is copolymerized with other polymerizable monomers suitable so that an alkali-soluble group such as a phenolic hydroxyl group or a carboxyl group can be introduced in order to maintain good developability for an alkali developer. In order to improve the film quality, other hydrophobic polymerizable monomers such as alkyl acrylate and alkyl methacrylate may be copolymerized.

The monomer corresponding to the repeating unit represented by the general formula (A2) includes (meth) acrylic acid chloride and an alcohol compound in a solvent such as THF, acetone and methylene chloride, and a basic catalyst such as triethylamine, pyridine and DBU. It can be synthesized by esterification below. A commercially available product may be used.
The monomer corresponding to the repeating unit represented by the general formula (A1) is a hydroxy-substituted styrene monomer and a vinyl ether compound in a solvent such as THF and methylene chloride, such as p-toluenesulfonic acid and p-toluenesulfonic acid pyridine salt. It can be synthesized by acetalization in the presence of an acidic catalyst or by t-Boc protection using t-butyl dicarbonate in the presence of a basic catalyst such as triethylamine, pyridine, DBU or the like. A commercially available product may be used.

The weight average molecular weight (Mw) of the resin (A) is preferably in the range of 1000 to 200,000, respectively. 200,000 or less is preferable from the viewpoint of the dissolution rate and sensitivity of the resin itself in alkali. The dispersity (Mw / Mn) is preferably 1.0 to 3.0, more preferably 1.0 to 2.5, and particularly preferably 1.0 to 2.0.
Among them, the weight average molecular weight (Mw) of the resin is preferably in the range of 1,000 to 200,000, more preferably in the range of 1,000 to 100,000, and particularly preferably 1,000. Is in the range of ~ 50,000, most preferably in the range of 1,000-25,000.
Here, the weight average molecular weight is defined by a polystyrene conversion value of gel permeation chromatography.

  Resin (A) having a dispersity of 2.0 or less can be synthesized by performing radical polymerization using an azo polymerization initiator. A resin (A) having a more preferable dispersion degree of 1.0 to 1.5 can be synthesized by living radical polymerization, for example.

The resin (A) is preferably polymerized by a known anionic polymerization method or radical polymerization method.
The anionic polymerization method is usually performed at a temperature of −100 to 90 ° C. in an organic solvent in an inert gas atmosphere such as nitrogen or argon using an alkali metal or an organic alkali metal as a polymerization initiator. In the copolymerization, a block copolymer is obtained by sequentially adding monomers to the reaction system for polymerization, and a random copolymer is obtained by adding a mixture of monomers to the reaction system for polymerization. can get.
Examples of the alkali metal of the polymerization initiator include lithium, sodium, potassium, cesium and the like, and examples of the organic alkali metal include alkylated products, allylated products and arylated products of the alkali metals, specifically Is ethyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, ethyl sodium, lithium biphenyl, lithium naphthalene, lithium triphenyl, sodium naphthalene, α-methylstyrene sodium dianion, 1,1-diphenylhexyl lithium 1,1-diphenyl-3-methylpentyl lithium and the like can be mentioned.
The radical polymerization method is a known radical polymerization start such as azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile, and organic oxides such as benzoyl peroxide, methyl ethyl ketone peroxide and cumene hydroperoxide. If necessary, a known chain transfer agent such as 1-dodecanethiol is used in combination with an inert gas atmosphere such as nitrogen or argon in an organic solvent at a temperature of 50 to 200 ° C. .
Examples of organic solvents include aliphatic hydrocarbons such as n-hexane and n-heptane, alicyclic hydrocarbons such as cyclohexane and cyclopentane, aromatic hydrocarbons such as benzene and toluene, and ketones such as methyl ethyl ketone and cyclohexanone. Propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monoethyl ether, etc. Polyhydric alcohol derivatives, ethers such as diethyl ether, tetrahydrofuran and dioxane, anisole, hex It can be mentioned organic solvents which are usually used in anionic polymerization such as methyl phosphoramide, which are used as a single solvent or two or more kinds of mixed solvents. More preferable solvents include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone.

Moreover, when exposing the positive resist of this invention with an ArF excimer laser, it is preferable that resin does not have an aromatic ring from a transparency viewpoint with respect to an ArF excimer laser.
Hereinafter, a resin suitable for ArF excimer laser exposure (hereinafter, also referred to as resin (A ′)) will be described.
Examples of the acid-decomposable group possessed by the resin (A ′) include those similar to those in the resin (A). The repeating unit containing an acid-decomposable group is preferably represented by the general formula (A2). Repeating units.
As for the content rate of the repeating unit which has an acid-decomposable group, 20-50 mol% is preferable with respect to all the repeating units in resin (A '), More preferably, it is 25-45 mol%.
The resin (A ′) preferably further has a repeating unit having at least one group selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group.

The repeating unit having a lactone group that can be contained in the resin (A ′) will be described.
Any lactone group can be used as long as it has a lactone structure, but it is preferably a 5- to 7-membered ring lactone structure, and forms a bicyclo structure or a spiro structure in the 5- to 7-membered ring lactone structure. The other ring structure is preferably condensed. It is more preferable to have a repeating unit having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). The lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and a specific lactone structure is used. This improves line edge roughness and development defects.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferably, they are a C1-C4 alkyl group, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring.

  Examples of the repeating unit having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AII).

In general formula (AII),
Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom. Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Preferred are a hydrogen atom, a methyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom and a methyl group are particularly preferred.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent linking group obtained by combining these. Preferably a single bond, -Ab ₁ -CO ₂ - is a divalent linking group represented by.
Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.
V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-16).

  The repeating unit having a lactone group usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

  The content of the repeating unit having a lactone group is preferably from 15 to 60 mol%, more preferably from 20 to 50 mol%, still more preferably from 30 to 50 mol%, based on all repeating units in the resin (A ′).

  Specific examples of the repeating unit having a lactone group are listed below, but the present invention is not limited thereto.

  The resin (A ′) preferably has a repeating unit having a hydroxyl group or a cyano group. This improves the substrate adhesion and developer compatibility. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferred hydroxyl group or cyano group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferred.

In general formulas (VIIa) to (VIIc),
R ₂ c to R ₄ c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group or a cyano group. Preferably, one or two of R ₂ c to R ₄ c are a hydroxyl group and the remaining is a hydrogen atom. In general formula (VIIa), more preferably, _two of R ₂ c to R ₄ c are hydroxyl groups and the remaining are hydrogen atoms.

  Examples of the repeating unit having a partial structure represented by the general formulas (VIIa) to (VIId) include the repeating units represented by the following general formulas (AIIa) to (AIId).

In the general formulas (AIIa) to (AIId),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₂ c to R ₄ c are in the general formula (VIIa) ~ (VIIc), same meanings as R ₂ c~R ₄ c.

  The content of the repeating unit having a hydroxyl group or a cyano group is preferably from 5 to 40 mol%, more preferably from 5 to 30 mol%, still more preferably from 10 to 25 mol%, based on all repeating units in the resin (A ′). .

  Specific examples of the repeating unit having a hydroxyl group or a cyano group are given below, but the present invention is not limited thereto.

  The resin (A ′) preferably has a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, and an aliphatic alcohol (for example, hexafluoroisopropanol group) substituted with an electron-attracting group at the α-position. It is more preferable to have a repeating unit. By containing the repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. The repeating unit having an alkali-soluble group includes a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or an alkali in the main chain of the resin through a linking group. Either a repeating unit to which a soluble group is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is used at the time of polymerization and introduced at the end of the polymer chain, and the linking group is monocyclic or polycyclic. It may have a cyclic hydrocarbon structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  The content of the repeating unit having an alkali-soluble group is preferably from 0 to 20 mol%, more preferably from 3 to 15 mol%, still more preferably from 5 to 10 mol%, based on all repeating units in the resin (A ′).

  Specific examples of the repeating unit having an alkali-soluble group are shown below, but the present invention is not limited thereto.

  The resin (A ′) may further have a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, diamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and cyclohexyl (meth) acrylate repeating units.

  In addition to the above repeating structural unit, the resin (A ′) has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general necessary characteristics of resist, such as resolution, heat resistance, and sensitivity. It can have various repeating structural units for adjusting purposes.

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

Thereby, the performance required for the resin (A ′), in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

The resin (A ′) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. 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 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

The weight average molecular weight of the resin (A ′) is preferably from 1,000 to 200,000, more preferably from 2,000 to 20,000, and even more preferably from 3,000 to 200 in terms of polystyrene by GPC method. 15,000, particularly preferably 3,000 to 10,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The degree of dispersion (molecular weight distribution) is usually 1 to 3, preferably 1 to 2.6, more preferably 1 to 2, and particularly preferably 1.4 to 1.7. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.

Two or more types of resins (A) may be used in combination.
The total amount of the resin (A) added is generally 10 to 99% by mass, preferably 20 to 99% by mass, particularly preferably 30 to 99% by mass, based on the total solid content of the positive resist composition. %.

  Specific examples of the resin (A) are shown below, but are not limited thereto.

(B) Compound that generates acid upon irradiation with actinic ray or radiation The positive resist composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter also referred to as “acid generator”). To do.
Examples of the acid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, a microresist, and the like, KrF excimer laser light, electron Known compounds that generate acid upon irradiation with actinic rays or radiation such as rays and EUV, and mixtures thereof can be appropriately selected and used.
Examples of such acid generators include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, o-nitrobenzyl sulfonates, and the like. More preferred is disulfone.

  Further, a group that generates an acid upon irradiation with actinic rays or radiation, 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-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, JP-A The compounds described in 63-146029 and the like can be used.

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

  Preferred compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII), and (ZIII).

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

Examples of the non-nucleophilic anion as Z ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide 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 aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

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

  The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as 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, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group and the like.

  The aromatic group in the aromatic 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 aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group , Hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 15 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group ( Preferably 2 to 7 carbon atoms, acyl group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (Preferably having 1 to 15 carbon atoms), alkyliminosulfonyl group (preferably having 2 to 15 carbon atoms), aryl Ruoxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), alkyloxyalkyloxy group (Preferably having 5 to 20 carbon atoms), a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.

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

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

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom and alkyl as in the aromatic sulfonate anion Group, cycloalkyl group, alkoxy group, alkylthio group and the like.

  Examples of the sulfonylimide anion include saccharin anion.

  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. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

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

Examples of the non-nucleophilic anion of Z ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, still more preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the 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 at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compounds, namely, compounds containing an arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group with the remaining being an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, 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 which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having 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 or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

The 2-oxoalkyl group may be either linear or branched, and a group having> C = O at the 2-position of the above alkyl group is preferable.
The 2-oxocycloalkyl group is preferably a group having> C═O at the 2-position of the cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy 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.

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

In general formula (ZI-3),
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 or a cycloalkyl group.
R _x and R _y independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure. It may contain an atom, an ester bond or an amide bond. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as Z ^{− in} formula (ZI).

The alkyl group as R _1c to R _7c may be linear or branched may be any of, for example, alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 linear or branched alkyl group having a carbon number ( Examples thereof include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

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, any of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c. Is 2-15. 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 _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _7c , such as a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as in R _{1c to} R _5c .

R _x and R _y are preferably an alkyl group or cycloalkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more alkyl groups or cycloalkyl groups.

In general formulas (ZII) and (ZIII),
R ₂₀₄ to 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. Aryl group R ₂₀₄ to R ₂₀₇ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R ₂₀₄ to R _207, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _207, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

Z ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of Z ^{− in} formula (ZI).

  Examples of the acid generator further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI), and those having a molecular weight of 3000 or less are preferable.

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

  As the acid generator, a compound capable of generating an acid having one sulfonic acid group or imide group is preferable, more preferably a compound generating a monovalent perfluoroalkanesulfonic acid, or a monovalent fluorine atom or fluorine atom. A compound that generates an aromatic sulfonic acid substituted with a group that generates or a compound that generates an imide acid substituted with a monovalent fluorine atom or a group containing a fluorine atom, and even more preferably, a fluorinated substituted alkane It is a sulfonium salt of sulfonic acid, fluorine-substituted benzenesulfonic acid, fluorine-substituted imide acid or fluorine-substituted methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

<Sulfonic acid generator>
A compound that generates sulfonic acid upon irradiation with actinic rays or radiation, which is preferable as an acid generator (also referred to as a sulfonic acid generator), is a compound that generates sulfonic acid upon irradiation with actinic rays or radiation such as KrF excimer laser light, electron beam, EUV, etc. Examples of such compounds are diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

From the viewpoint of improving image performance such as resolution and pattern shape, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, and disulfones are preferable.
From the viewpoint of remaining low standing waves, more preferred are imide sulfonate, oxime sulfonate, diazodisulfone, and disulfone, and still more preferred are oxime sulfonate and diazodisulfone.
The sulfonic acid generator can be synthesized by a known method such as a synthesis method described in JP-A-2002-27806.

  Examples of particularly preferred sulfonic acid generators are given below.

The content of the acid generator is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, particularly preferably 1 to 10% by mass, based on the total solid content of the positive resist composition. %. That is, 1% by mass or more is preferable from the viewpoint of sensitivity and line edge roughness, and 10% by mass or less is preferable from the viewpoint of resolution, pattern shape, and film quality.
In addition, one type of acid generator may be used, or two or more types may be mixed and used. For example, as the acid generator, a compound that generates aryl sulfonic acid upon irradiation with active light or radiation and a compound that generates alkyl sulfonic acid upon irradiation with active light or radiation may be used in combination.

<Carboxylic acid generator>
As the acid generator, a compound that generates a carboxylic acid upon irradiation with actinic rays or radiation (also referred to as a carboxylic acid generator) may be used.
As the carboxylic acid generator, a compound represented by the following general formula (C) is preferable.

In the general formula (C), R _{21 to} R ₂₃ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, and R ₂₄ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group. Z represents a sulfur atom or an iodine atom. When Z is a sulfur atom, p is 1, and when Z is an iodine atom, p is 0.

In the general formula (C), R _{21 to} R ₂₃ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group, and these groups may have a substituent.
Examples of the substituent that the alkyl group, cycloalkyl group or alkenyl group may have include a halogen atom (a chlorine atom, a bromine atom, a fluorine atom, etc.), an aryl group (a phenyl group, a naphthyl group, etc.), a hydroxy group, An alkoxy group (methoxy group, ethoxy group, butoxy group, etc.) etc. can be mentioned.
Examples of the substituent that the aryl group may have include a halogen atom (chlorine atom, bromine atom, fluorine atom, etc.), nitro group, cyano group, alkyl group (methyl group, ethyl group, t-butyl group, t -Amyl group, octyl group, etc.), hydroxy group, alkoxy group (methoxy group, ethoxy group, butoxy group, etc.) and the like.

R _{21 to} R ₂₃ are preferably each independently an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aryl group having 6 to 24 carbon atoms. And more preferably an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 15 carbon atoms. Each of these groups may have a substituent.

R ₂₄ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group.
Examples of the substituent that the alkyl group, cycloalkyl group, and alkenyl group may have are the same as those described as examples of the substituent when R ₂₁ is an alkyl group.
Examples of the substituent for the aryl group, the R ₂₁ may be the same as those mentioned as examples of the substituent when it is an aryl group.

R ₂₄ is preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 24 carbon atoms, and more Preferably, they are a C1-C18 alkyl group, a C3-C18 cycloalkyl group, and a C6-C18 aryl group, Most preferably, a C1-C12 alkyl group, C3-C3 A cycloalkyl group having 12 carbon atoms and an aryl group having 6 to 15 carbon atoms. Each of these groups may have a substituent.

Z represents a sulfur atom or an iodine atom. p is 1 when Z is a sulfur atom, and 0 when Z is an iodine atom.
Two or more cation moieties of formula (C) are bonded by a single bond or a linking group (for example, -S-, -O-, etc.) to form a cation structure having a plurality of cation moieties of formula (C). May be.

  Although the preferable specific example of a carboxylic acid generator is given to the following, of course, it is not limited to these.

When the carboxylic acid generator is used, the content in the positive resist composition of the present invention is preferably 0.01 to 10% by mass, more preferably 0.03 to 4, based on the total solid content of the composition. It is 5 mass%, Most preferably, it is 0.05-3 mass%. One type of carboxylic acid generator may be used, or two or more types may be mixed and used.
The carboxylic acid generator can be synthesized by a known method such as the synthesis method described in JP-A-2002-27806.
When the sulfonic acid generator (B) and the carboxylic acid generator (C) are used in combination, the C / B (mass ratio) is usually 99.9 / 0.1-50 / 50, preferably 99 / 1-60. / 40, particularly preferably 98/2 to 70/30.

(C) Organic basic compound The positive resist composition of the present invention preferably contains an organic basic compound. The organic basic compound is preferably a compound that is more basic than phenol. The molecular weight of the organic basic compound is usually 100 to 900, preferably 150 to 800, more preferably 200 to 700. Further, nitrogen-containing basic compounds are particularly preferable.
Preferred nitrogen-containing basic compounds are compounds having structures of the following formulas (CI) to (CV) as a preferred chemical environment. Formulas (CII) to (CV) may be part of a ring structure.

Here, R ₂₅₀ , R ₂₅₁ and R ₂₅₂ may be the same or different and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group. (Preferably having 6 to 20 carbon atoms), wherein R ₂₅₁ and R ₂₅₂ may be bonded to each other to form a ring.

  The alkyl group may be unsubstituted or may have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 6 carbon atoms and a hydroxyalkyl group having 1 to 6 carbon atoms. preferable.

R ₂₅₃ , R ₂₅₄ , R ₂₅₅ and R ₂₅₆ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms.

  Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.

  Further, at least one nitrogen-containing compound selected from an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group can be exemplified. .

As the amine compound, a primary, secondary or tertiary amine compound can be used, and an amine compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. The amine compound is more preferably a tertiary amine compound. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the amine compound has an cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 3 to 20 carbon atoms). Preferably C6-C12) may be bonded to a nitrogen atom. The amine compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

As the ammonium salt compound, a primary, secondary, tertiary, or quaternary ammonium salt compound can be used, and an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the ammonium salt compound has a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group in addition to the alkyl group. (Preferably having 6 to 12 carbon atoms) may be bonded to a nitrogen atom. The ammonium salt compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group. Examples of the anion of the ammonium salt compound include halogen atoms, sulfonates, borates, and phosphates. Among them, halogen atoms and sulfonates are preferable. As the halogen atom, chloride, bromide, and iodide are particularly preferable. As the sulfonate, an organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include alkyl sulfonates having 1 to 20 carbon atoms and aryl sulfonates. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, alkoxy groups, acyl groups, and aryl groups. Specific examples of the alkyl sulfonate include methane sulfonate, ethane sulfonate, butane sulfonate, hexane sulfonate, octane sulfonate, benzyl sulfonate, trifluoromethane sulfonate, pentafluoroethane sulfonate, and nonafluorobutane sulfonate. Examples of the aryl group of the aryl sulfonate include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, naphthalene ring and anthracene ring may have a substituent, and the substituent is preferably a linear or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the linear or branched alkyl group and cycloalkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl, cyclohexyl and the like. Examples of the other substituent include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, cyano, nitro, an acyl group, and an acyloxy group.

The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound or ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. Etc. The substitution position of the substituent may be any of the 2-6 positions. The number of substituents may be any in the range of 1 to 5.
It is preferable to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  The amine compound having a phenoxy group is prepared by reacting a primary or secondary amine having a phenoxy group with a haloalkyl ether by heating, and then adding an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide or tetraalkylammonium. Then, it can be obtained by extraction with an organic solvent such as ethyl acetate or chloroform. Alternatively, after reacting by heating a primary or secondary amine and a haloalkyl ether having a phenoxy group at the end, an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide, or tetraalkylammonium is added, and then ethyl acetate, It can be obtained by extraction with an organic solvent such as chloroform.

  In the amine compound having a sulfonic acid ester group and the ammonium salt compound having a sulfonic acid ester group, the sulfonic acid ester group may be any of alkyl sulfonic acid ester, cycloalkyl group sulfonic acid ester, and aryl sulfonic acid ester. In the case of an alkyl sulfonate ester, the alkyl group has 1 to 20 carbon atoms, in the case of a cycloalkyl sulfonate ester, the cycloalkyl group has 3 to 20 carbon atoms, and in the case of an aryl sulfonate ester, the aryl group has 6 carbon atoms. ~ 12 are preferred. Alkyl sulfonic acid ester, cycloalkyl sulfonic acid ester, and aryl sulfonic acid ester may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid. An ester group is preferred.

It is preferable to have at least one oxyalkylene group between the sulfonate group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  Preferred organic basic compounds include guanidine, aminopyridine, aminoalkylpyridine, aminopyrrolidine, indazole, imidazole, pyrazole, pyrazine, pyrimidine, purine, imidazoline, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and the like. . These may have a substituent, and preferred substituents include amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl Group, aryloxy group, nitro group, hydroxyl group, cyano group and the like.

  Particularly preferred organic basic compounds include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenyl. Imidazole, 4,5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine 4-aminoethylpyridine, 3-aminopi Lysine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-imino Piperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methyl Examples include, but are not limited to, pyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine. Is not to be done.

A tetraalkylammonium salt type nitrogen-containing basic compound can also be used.
Of these, tetraalkylammonium hydroxide having 1 to 8 carbon atoms (tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra- (n-butyl) ammonium hydroxide, etc.) is particularly preferable. These nitrogen-containing basic compounds are used alone or in combination of two or more.

  The use ratio of the acid generator and the organic basic compound in the composition is preferably organic basic compound / acid generator (molar ratio) = 0.01-10. That is, the molar ratio is preferably 10 or less from the viewpoint of sensitivity and resolution, and is preferably 0.01 or more from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The organic basic compound / acid generator (molar ratio) is more preferably 0.05 to 5, and still more preferably 0.1 to 3.

(D) Surfactant In the present invention, a surfactant can be used, which is preferable from the viewpoints of film forming properties, pattern adhesion, development defect reduction, and the like.

Specific examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene Polyoxyethylene alkyl allyl ethers such as nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Sorbitan fatty acid esters such as rate, polyoxyethylene sorbitan monolaurate, polyoxyethylene Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as bitane monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, Ftop EF301, EF303, EF352 (manufactured by Shin-Akita Kasei Co., Ltd.), MegaFuck F171, F173 (manufactured by Dainippon Ink and Chemicals), Florad FC430, FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.) and other fluorine-based surfactants or silicon-based surfactants, organosilanes Hexane polymer KP341 (manufactured by Shin-Etsu Chemical Co.) and acrylic or methacrylic acid-based (co) polymer Polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.). The compounding amount of these surfactants is usually 2 parts by mass or less, preferably 1 part by mass or less per 100 parts by mass of the solid content in the composition of the present invention.
These surfactants may be added alone or in some combination.

The surfactant is any one of fluorine and / or silicon surfactants (fluorine surfactants and silicon surfactants, surfactants containing both fluorine atoms and silicon atoms), or It is preferable to contain 2 or more types.
As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), PF6320 Fluorosurfactants such as (manufactured by OMNOVA) or silicon surfactants 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 linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

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

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

Compound (PA) having a proton acceptor functional group and decomposing upon irradiation with actinic rays or radiation to generate a compound whose proton acceptor property is lowered, disappeared, or changed from proton acceptor property to acidity
The positive resist composition of the present invention has a proton acceptor functional group in terms of sensitivity, resolution, and line edge roughness, and is degraded by irradiation with actinic rays or radiation, resulting in a decrease in proton acceptor properties. It is preferable to contain a compound (hereinafter also referred to as “compound (PA)”) that generates a compound that has disappeared or changed from proton acceptor properties to acidic properties.

A compound (PA) generated by decomposition by irradiation with actinic rays or radiation, wherein the proton acceptor property is lowered, disappears, or is changed from proton acceptor property to acid, is represented by the following general formula (PA-I) Mention may be made of the compounds represented.
Q-A- (X) nBR (PA-1)
In general formula (PA-I),
Q represents a sulfo group (—SO ₃ H) or a carboxyl group (—CO ₂ H).
A represents a divalent linking group.
X is, -SO ₂ - represents a or -CO-.
n represents 0 or 1.
B represents a single bond, an oxygen atom or -N (Rx)-. Rx represents a hydrogen atom or a monovalent organic group.
R represents a monovalent organic group having a proton acceptor functional group or a monovalent organic group having an ammonium group.

The divalent linking group in A is preferably a divalent linking group having 2 to 12 carbon atoms, and examples thereof include an alkylene group and a phenylene group. More preferably, it is an alkylene group having at least one fluorine atom, and a preferable carbon number is 2 to 6, more preferably 2 to 4. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is particularly preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, and more preferably, the carbon atom bonded to the Q site has a fluorine atom.
Further, a perfluoroalkylene group is preferable, and a perfluoroethylene group, a perfluoropropylene group, and a perfluorobutylene group are more preferable.

The monovalent organic group in Rx preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.
The alkyl group in Rx may have a substituent, preferably a linear or branched alkyl group having 1 to 20 carbon atoms, and has an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain. May be. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.
Examples of the alkyl group having a substituent include groups in which a linear or branched alkyl group is substituted with a cycloalkyl group (for example, an adamantylmethyl group, an adamantylethyl group, a cyclohexylethyl group, a camphor residue, etc.). .
The cycloalkyl group in Rx may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom in the ring. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Rx may have a substituent and is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.
The aralkyl group in Rx may have a substituent, preferably an aralkyl group having 7 to 20 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a naphthylmethyl group, and a naphthylethyl group.
The alkenyl group in Rx may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group mentioned as Rx.

  The proton acceptor functional group in R is a group capable of electrostatically interacting with protons or a functional group having electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether. Or a functional group having a nitrogen atom with a lone electron pair that does not contribute to π conjugation. The nitrogen atom having a lone electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure represented by the following general formula.

Preferable partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, tertiary amine, secondary amine, primary amine, pyridine, imidazole, pyrazine structure and the like.
Preferred examples of the partial structure of the ammonium group include tertiary ammonium, secondary ammonium, primary ammonium, pyridinium, imidazolinium, and pyrazinium structures.
The group containing such a structure preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.
The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, the alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group in the proton-accepting functional group or ammonium group in R are represented by Rx. These are the same as the alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group mentioned.

  Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C20) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20). As for the aminoacyl group, examples of the substituent further include 1 or 2 alkyl groups (preferably having 1 to 20 carbon atoms).

When B is -N (Rx)-, R and Rx are preferably bonded to each other to form a ring. By forming the ring structure, the stability is improved, and the storage stability of the composition using the ring structure is improved. The number of carbon atoms forming the ring is preferably 4 to 20, and may be monocyclic or polycyclic, and may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the ring.
Examples of the monocyclic structure include a 4-membered ring, a 5-membered ring, a 6-membered ring, a 7-membered ring, and an 8-membered ring containing a nitrogen atom. Examples of the polycyclic structure include a structure composed of a combination of two or three or more monocyclic structures. The monocyclic structure and polycyclic structure may have a substituent, for example, a halogen atom, a hydroxyl group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), Aryl group (preferably having 6 to 14 carbon atoms), alkoxy group (preferably having 1 to 10 carbon atoms), acyl group (preferably having 2 to 15 carbon atoms), acyloxy group (preferably having 2 to 15 carbon atoms), alkoxycarbonyl A group (preferably having 2 to 15 carbon atoms), an aminoacyl group (preferably having 2 to 20 carbon atoms) and the like are preferable. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 15). As for the aminoacyl group, examples of the substituent include 1 or 2 alkyl groups (preferably having 1 to 15 carbon atoms).

  Among the compounds represented by the general formula (PA-I), a compound in which the Q site is a sulfonic acid can be synthesized by using a general sulfonamidation reaction. For example, a method in which one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine compound to form a sulfonamide bond, and then the other sulfonyl halide part is hydrolyzed, or a cyclic sulfonic acid anhydride is used. It can be obtained by a method of ring-opening by reacting with an amine compound.

  Hereinafter, although the specific example of a compound represented by general formula (PA-I) is shown, this invention is not limited to this.

  The compound represented by the following general formula (PA-II), which is generated by the decomposition of the compound (PA) upon irradiation with actinic rays or radiation and whose proton acceptor property is lowered, disappeared, or changed from proton acceptor property to acidity, ) Can be mentioned.

In general formula (PA-II),
Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either _one of Q ₁ and Q ₂ has a proton acceptor functional group. Q ₁ and Q ₂ may be bonded to each other to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ and X ₂ each independently represent —CO— or —SO ₂ —.

The monovalent organic groups as Q ₁ and Q _{2 in} formula (PA-II) preferably have 1 to 40 carbon atoms, and examples thereof include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, An alkenyl group etc. can be mentioned.
The alkyl group in Q ₁ and Q ₂ may have a substituent, preferably a linear or branched alkyl group having 1 to 30 carbon atoms, and an oxygen atom, sulfur atom, nitrogen atom in the alkyl chain You may have. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.
The cycloalkyl group in Q ₁ and Q ₂ may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom or a nitrogen atom in the ring. Good. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Q ₁ and Q ₂ may have a substituent, and preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group and a naphthyl group.
The aralkyl group in Q _1, Q _2, which may have a substituent, is preferably an aralkyl group having 7 to 20 carbon atoms, for example, benzyl group, phenethyl group, naphthylmethyl group, naphthylethyl group Is mentioned.
The alkenyl group for Q ₁ and Q ₂ may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group.
Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C10) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 10). Examples of the alkyl group having a substituent include perfluoroalkyl groups such as a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, and a perfluorobutyl group.

One of the monovalent organic groups of Q ₁ and Q ₂ has a proton acceptor functional group.

  The proton acceptor functional group may be substituted with an organic group having a bond that is cleaved by an acid. Examples of the organic group having a bond that can be cleaved by an acid include an amide group, an ester group (preferably a tertiary alkyloxycarbonyl group), an acetal group (preferably a 1-alkyloxy-alkyloxy group), and a carbamoyl group. Group, carbonate group and the like.

Q ₁ and Q ₂ are bonded to each other to form a ring, and the formed ring has a proton acceptor functional group. For example, the organic group of Q ₁ and Q ₂ is further an alkylene group, an oxy And a structure bonded with a group, an imino group or the like.

In formula (PA-II), at least one of X ₁ and X _2, -SO ₂ - is preferably.

  The compound represented by the general formula (PA-II) is preferably a compound represented by the following general formula (PA-III).

In general formula (PA-III),
Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ has a proton acceptor functional group. Q _1, Q ₃ are bonded to each other to form a ring, and the ring formed may have a proton acceptor functional group.
X ₁ , X ₂ and X ₃ each independently represent —CO— or —SO ₂ —.
A represents a divalent linking group.
B represents a single bond, an oxygen atom, or —N (Qx) —.
Qx represents a hydrogen atom or a monovalent organic group.
When B is —N (Qx) —, Q ₃ and Qx may be bonded to each other to form a ring.
n represents 0 or 1.

Q ₁ has the same meaning as Q _{1 in} formula (PA-II).
Examples of the organic group of Q ₃ include the same organic groups as Q ₁ and Q ₂ in formula (PA-II).

  The divalent linking group in A is preferably a divalent linking group having 1 to 8 carbon atoms, for example, an alkylene group having 1 to 8 carbon atoms, a phenylene group having a fluorine atom. Etc. An alkylene group having a fluorine atom is more preferable, and a preferable carbon number is 2 to 6, more preferably 2 to 4. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, more preferably a perfluoroalkylene group, and particularly preferably a perfluoroethylene group, a perfluoropropylene group, or a perfluorobutylene group. .

  The monovalent organic group in Qx is preferably an organic group having 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. Examples of the alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group are the same as those described above.

In the general formula (PA-III), X ₁ , X ₂ and X ₃ are preferably —SO ₂ —.

  Hereinafter, although the specific example of a compound represented by general formula (PA-II) is shown, this invention is not limited to this.

  As the compound (PA), a sulfonium salt compound of the compound represented by the general formula (PA-I), (PA-II) or (PA-III), the general formula (PA-I), (PA-II) or The iodonium salt compound of the compound represented by (PA-III) is preferable, and the compound represented by the following general formula (PA1) or (PA2) is more preferable.

In general formula (PA1):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ^- is the general formula (PA-I) -SO ₃ H site or -COOH moiety of the hydrogen atoms are balanced sulfonate or carboxylate anion of the compound represented by, or formula (PA-II) or (PA -III) represents an anion of the compound represented by

The carbon number of the organic group in R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
It is also possible to form the two members to ring structure of the R ₂₀₁ to R _203, an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Examples of the group formed by combining two of R _{201 to} R ₂₀₃ with each other include an alkylene group (eg, butylene group, pentylene group).
Specific examples of the organic group in R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the corresponding groups in the compounds (A1a), (A1b) and (A1c) described later.
In addition, the compound which has two or more structures represented by general formula (PA1) may be sufficient. For example, at least one of R ₂₀₁ to R ₂₀₃ of the compound represented by the general formula (PA1) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (PA1) It may be a compound.

  As more preferred (PA1) component, compounds (A1a), (A1b), and (A1c) described below can be exemplified.

Compound (A1a) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (PA1), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, a diarylcycloalkylsulfonium compound, an aryldialkylsulfonium compound, an aryldicycloalkylsulfonium compound, and an arylalkylcycloalkylsulfonium compound.
The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most preferably They are a C1-C4 alkyl group and a C1-C4 alkoxy group. The substituent may be substituted on any one of three R ₂₀₁ to R _203, or may be substituted on all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (A1b) will be described.
The compound (A1b) is a compound in which R _{201 to} R ₂₀₃ in the general formula (PA1) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring having a hetero atom.
The organic group not having an aromatic ring in R ₂₀₁ to R _203, generally from 1 to 30 carbon atoms, preferably an organic group having 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 or branched 2-oxoalkyl group, 2-oxocycloalkyl group, An alkoxycarbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.
The alkyl group in R _{201 to} R ₂₀₃ may be linear or branched, and is preferably a linear or branched alkyl group having 1 to 20 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group, an alkoxycarbonylmethyl group are preferred.
Preferred examples of the cycloalkyl group for R _{201 to} R ₂₀₃ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxocycloalkyl group is more preferable.
The linear or branched 2-oxoalkyl group in R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably has> C═O at the 2-position of the alkyl group. The group can be mentioned.
The 2-oxocycloalkyl group in R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably includes a group having> C═O at the 2-position of the cycloalkyl group. be able to.
The alkoxy group in the alkoxycarbonylmethyl group of R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), an alkoxycarbonyl group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. .

  The compound (A1c) is a compound represented by the following general formula (A1c), and is a compound having an arylacylsulfonium salt structure.

In general formula (A1c):
_R213 represents an aryl group which may have a substituent, and is preferably a phenyl group or a naphthyl group. Preferred substituents in R _213, an alkyl group, an alkoxy group, an acyl group, a nitro group, a hydroxyl group, an alkoxycarbonyl group and a carboxy group.
R ₂₁₄ and R ₂₁₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Y ₂₀₁ and Y ₂₀₂ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or a vinyl group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (PA-I) is removed, or a general formula (PA-II) or (PA -III) represents an anion of the compound represented by
R ₂₁₃ and R ₂₁₄ may be bonded to form a ring structure, respectively, R ₂₁₄ and R ₂₁₅ may be bonded to form a ring structure, respectively, Y ₂₀₁ and Y ₂₀₂ are each They may be bonded to each other to form a ring structure. These ring structures may contain an oxygen atom, a sulfur atom, an ester bond, or an amide bond. Examples of the group formed by combining R ₂₁₃ and R ₂₁₄ , R ₂₁₄ and R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ with each other include a butylene group and a pentylene group.

As the alkyl group for R ₂₁₄ , R ₂₁₅ , Y _201, and Y ₂₀₂ , a linear or branched alkyl group having 1 to 20 carbon atoms is preferable. Examples of the alkyl group for Y ₂₀₁ and Y ₂₀₂ include a 2-oxoalkyl group having> C═O at the 2-position of the alkyl group, an alkoxycarbonylalkyl group (preferably an alkoxy group having 2 to 20 carbon atoms), and a carboxyalkyl group. More preferred.
The cycloalkyl group for R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a cycloalkyl group having 3 to 20 carbon atoms.

Y ₂₀₁ and Y ₂₀₂ are preferably an alkyl group having 4 or more carbon atoms, more preferably an alkyl group having 4 to 6, and further preferably 4 to 12.
In addition, at least one of R ₂₁₄ or R ₂₁₅ is preferably an alkyl group, and more preferably both R ₂₁₄ and R ₂₁₅ are alkyl groups.

In the general formula (PA2),
_R204 and _R205 each independently represents an aryl group, an alkyl group or a cycloalkyl group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (PA-I) is removed, or a general formula (PA-II) or (PA -III) represents an anion of the compound represented by

The aryl group of R ₂₀₄ and R _205, a phenyl group, a naphthyl group, more preferably a phenyl group.
The alkyl group in R ₂₀₄ and R ₂₀₅ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group).
Preferred examples of the cycloalkyl group for R ₂₀₄ and R ₂₀₅ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
_R204 and _R205 may have a substituent. Examples of the substituent that R ₂₀₄ and R ₂₀₅ may have include, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 6 carbon atoms). 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

  The compound that generates the compound represented by the general formula (PA-I), (PA-II), or (PA-III) upon irradiation with actinic rays or radiation is preferably represented by the general formula (PA1). A compound, more preferably compounds (A1a) to (A1c).

Compound (PA) decomposes upon irradiation with actinic rays or radiation to generate, for example, a compound represented by general formula (PA-1) or (PA-2).
The compound represented by the general formula (PA-1) has a sulfo group or a carboxyl group together with a proton acceptor functional group, so that the proton acceptor property is lowered or disappeared compared to the compound (PA), or the proton acceptor. It is a compound that has changed from scepter to acidic.
The compound represented by the general formula (PA-2) has an organic sulfonylimino group or an organic carbonylimino group together with a proton acceptor functional group, so that the proton acceptor property decreases and disappears compared to the compound (PA). Or a compound that is changed from proton acceptor property to acidity.
In the present invention, the acceptor property is lowered when the non-covalent complex which is a proton adduct is formed from a compound having a proton acceptor functional group and a proton, and the equilibrium constant in the chemical equilibrium is reduced. Means.
Proton acceptor property can be confirmed by measuring pH.

  Hereinafter, although the specific example of the compound (PA) which generate | occur | produces the compound represented with general formula (PA-I) by irradiation of actinic light or a radiation is given, this invention is not limited to this.

  These compounds are synthesized from a compound represented by the general formula (PA-I) or a lithium, sodium or potassium salt thereof and a hydroxide, bromide or chloride of iodonium or sulfonium. Or a salt exchange method described in JP-A No. 2003-246786.

  Hereinafter, although the specific example of the compound (PA) which generate | occur | produces the compound represented by general formula (PA-II) by irradiation of actinic light or a radiation is given, this invention is not limited to this.

These compounds can be easily synthesized by using a general sulfonic acid esterification reaction or sulfonamidation reaction. For example, one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine or alcohol containing a partial structure represented by the general formula (PA-II) to form a sulfonamide bond or a sulfonate bond Then, the other sulfonyl halide moiety can be hydrolyzed, or the cyclic sulfonic acid anhydride can be opened by an amine or alcohol containing a partial structure represented by the general formula (PA-II). . An amine or alcohol containing a partial structure represented by the general formula (PA-II) is an amine, an alcohol such as (R′O ₂ C) ₂ O or an anhydride such as R′O ₂ CCl, acid It can be synthesized by reacting with a chloride compound.

  The content of the compound (PA) in the positive resist composition of the present invention is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on the solid content of the composition.

Other Components The positive resist composition of the present invention can further contain a dye, a photobase generator and the like, if necessary.

1. Dye A dye can be used in the present invention.
Suitable dyes include oily dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (oriental chemical industry) Co., Ltd.), crystal violet (CI42555), methyl violet (CI42535), rhodamine B (CI45170B), malachite green (CI42000), methylene blue (CI522015) and the like.

2. Photobase generator As photobase generators that can be added to the composition of the present invention, JP-A-4-151156, JP-A-4-162040, JP-A-5-197148, JP-A-5-5995, JP-A-6-194835, Examples thereof include compounds described in JP-A-8-146608, JP-A-10-83079 and European Patent No. 622682, specifically, 2-nitrobenzylcarbamate, 2,5-dinitrobenzylcyclohexylcarbamate, N-cyclohexyl-4- Methylphenylsulfonamide, 1,1-dimethyl-2-phenylethyl-N-isopropylcarbamate and the like can be suitably used. These photobase generators are added for the purpose of improving the resist shape and the like.

3. Antioxidant The positive resist composition of the present invention may use an antioxidant as an additive.
The antioxidant is for preventing the organic material from being oxidized in the presence of oxygen. The antioxidant is not particularly limited as long as it is effective in preventing the oxidation of commonly used plastics, for example, a phenolic antioxidant, an antioxidant made of an organic acid derivative, and a sulfur-containing agent. Antioxidants, phosphorus antioxidants, amine antioxidants, antioxidants composed of amine-aldehyde condensates, antioxidants composed of amine-ketone condensates, and the like. Of these antioxidants, a phenolic antioxidant as an antioxidant and an antioxidant composed of an organic acid derivative are used to exhibit the effects of the present invention without deteriorating the function of the resist. It is preferable.

  Examples of phenolic antioxidants include substituted phenols such as 1-oxy-3-methyl-4-isopropylbenzene, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4. -Ethylphenol, 2,6-di-tert-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-tert-butylphenol, butyl hydroxyanisole, 2- (1-methylcyclohexyl)- 4,6-dimethylphenol, 2,4-dimethyl-6-tert-butylphenol, 2-methyl-4,6-dinonylphenol, 2,6-di-tert-butyl-α-dimethylamino-p-cresol 6- (4-hydroxy-3,5-di-tert-butylanilino) 2,4-bisoctyl-thio-1,3,5-triazine, n-octadecyl 3- (4′-hydroxy-3 ′, 5′-di-tert-butylphenyl) propionate, octylated phenol, aralkyl-substituted phenols, alkylated p-cresol, hindered phenol, etc. , Tris, polyphenols such as 4,4'-dihydroxy diphenyl, methylene bis (dimethyl-4,6-phenol), 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol) ), 2,2′-methylene-bis- (4-methyl-6-cyclohexyl phenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′- Methylene-bis- (2,6-di-tert-butylphenol), 2,2′-methylene-bis- (6-alphamethyl-benzyl-p-creso ), Methylene bridged polyhydric alkylphenol, 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2 ′ -Dihydroxy-3,3'-di- (α-methylcyclohexyl) -5,5'-dimethyl diphenylmethane, alkylated bisphenol, hindered bisphenol, 1,3,5-trimethyl-2,4,6-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tetrakis- [methylene-3- (3 ′, 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane and the like.

  Preferable specific examples of the antioxidant used in the present invention include 2,6-di-t-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-t-butylphenol, and 2,2′-methylenebis. (4-methyl-6-t-butylphenol), butylhydroxyanisole, t-butylhydroquinone, 2,4,5-trihydroxybutyrophenone, nordihydroguaiaretic acid, propyl gallate, octyl gallate, lauryl gallate, And isopropyl citrate. Of these, 2,6-di-t-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-t-butylphenol, butylhydroxyanisole, and t-butylhydroquinone are preferred, and 2,6-diethyl is further preferred. -T-Butyl-4-methylphenol or 4-hydroxymethyl-2,6-di-t-butylphenol is more preferred.

  When the antioxidant is used, the content in the positive resist composition of the present invention is preferably 1 ppm or more, more preferably 5 ppm or more, further preferably 10 ppm or more, even more preferably 50 ppm or more, particularly Preferably it is 100 ppm or more, Most preferably, it is 100-1000 ppm. One type of antioxidant may be used, or two or more types may be mixed.

4). Solvents The positive resist composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. The solid content concentration of all resist components is usually preferably 2 to 30% by mass, more preferably 3 to 25% by mass.
Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. Or mixed to use.
In particular, it is preferable to use a solvent containing propylene glycol monomethyl ether acetate or propylene glycol monomethyl ether, and it is more preferable to use a mixed solvent containing propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether.

  The positive resist composition of the present invention is applied onto a substrate to form a thin film. The thickness of this coating film is preferably 0.05 to 4.0 μm.

  The composition of the present invention is excellent in that the generation of a standing wave is remarkably suppressed and a good pattern can be obtained even when it is directly applied to a substrate having a highly reflective surface without applying an antireflection film. Although effective, a good pattern can be formed even if an antireflection film is used.

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

In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.
Further, if necessary, an antireflection film can be used as an upper layer of the resist.
Examples of the antireflection film include AQUATAR-II, AQUATAR-III, and AQUATAR-VII manufactured by AZ Electronic Materials.

In the manufacture of precision integrated circuit elements, the pattern forming process on the resist film is carried out on the substrate (eg, silicon / silicon dioxide coated substrate, glass substrate, ITO substrate, quartz / chromium oxide coated substrate, etc.). A resist composition is applied to form a resist film, followed by irradiation with actinic rays or radiation such as KrF excimer laser light, ArF excimer laser light, electron beam, EUV light, etc., heating, development, rinsing and drying. As a result, a good resist pattern can be formed.
The resist composition of the present invention has a low substrate dependency, and particularly a basic substrate such as SiN (silicon nitride film) or SiON, an insulating film such as BPSG (boron-phosphorus-silicate glass), or TiN (titanium nitride). Even if it is a board | substrate with which the film | membrane was provided, even when it is a case where a resist film is directly formed on a board | substrate, without providing an antireflection film etc., it can use suitably.
The pattern forming method of the present invention is preferably carried out by forming a resist film (directly) on a basic substrate.

Examples of the alkaline developer used in development include inorganic alkalis 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, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, An aqueous solution (usually 0.1 to 20% by mass) of an alkali such as a quaternary ammonium salt such as choline or a cyclic amine such as pyrrole or piperidine can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.
Among these developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and choline are more preferable.
The pH of the alkali developer is usually 10-15.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, the content of this invention is not limited by this.

<Resin used in Examples>
The structure of the resin (A) used in the following examples is as described above, and the composition ratio (molar ratio), weight average molecular weight (Mw), and dispersity (Mw / Mn) are as follows.

(Preparation of resist composition)
Shown in each table below,
(N) Compound having at least one nitro group and one acid group: Amount shown in the following tables Resin: Amount shown in the following tables Acid generator: 0.03 g
Basic compound / compound (PA): 0.003 g
Surfactant: 0.001 g
Was dissolved in 14 g of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether (PGMEA / PGME, mass ratio 8/2), and the obtained solution was microfiltered with a membrane filter having a pore size of 0.1 μm to obtain a resist solution. .
However, when the compound (PA) and the basic compound were used in combination, the proton acceptor group-containing compound was 0.0015 g and the basic compound was 0.0015 g.
In addition, about the resist using the resin obtained as a propylene glycol monomethyl ether acetate (PGMEA) solution in a synthesis example, the resin solution of 0.966g in conversion of solid content of resin is used, and the solvent of the final resist solution is used. The amount of solvent added was adjusted so that the composition ratio was propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether (PGMEA / PGME) = 8/2 (mass ratio).

<KrF exposure>
An 8-inch SiN (100 nm) wafer was subjected to hexamethyldisilazane treatment using a spin coater ACT8 manufactured by Tokyo Electron, and then the resist solution obtained above was applied and baked at 130 ° C. for 60 seconds. A film having an average film thickness of 420 nm was obtained.
The obtained resist film was subjected to pattern exposure using a KrF excimer laser scanner (PAS5500 / 850C manufactured by ASML, wavelength 248 nm, NA = 0.70, Sigma = 0.80). After irradiation, it was baked at 130 ° C. for 60 seconds, developed with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.
The results are shown in Table 2.

〔sensitivity〕
The line width of the obtained pattern was observed with a scanning electron microscope (S-9260, manufactured by Hitachi, Ltd.), and the irradiation energy (mJ / cm ² ) when resolving a 0.15 μm line (line: space = 1: 1). ) As sensitivity.

[Profile shape]
The profile of the pattern obtained above was observed with a cross-sectional SEM, and the following three-stage evaluation was performed.
1: When there is no skirt shape and is a rectangle 2: When a slightly skirt shape is observed, but when it is almost a rectangle 3: When it is clearly a skirt shape

Hereinafter, abbreviations in the table are shown.
Basic compound D-1: Dicyclohexylmethylamine D-2: 2,4,6-triphenylimidazole

D-3:

Surfactant W-1: Fluorosurfactant, PF6320 (manufactured by OMNOVA)
W-2: Fluorine / silicone surfactant, MegaFac R08 (manufactured by Dainippon Ink & Chemicals, Inc.)
W-3: Silicon-based surfactant, siloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

  From the results shown in Table 2, it can be seen that the positive resist composition of the present invention is highly sensitive and has no substrate dependency and is excellent in profile shape in KrF exposure.

<EB exposure>
Similarly to the patterning by the KrF exposure, a resist solution prepared using the components shown in Table 3 below was applied onto a 6-inch SiN (100 nm) wafer subjected to hexamethyldisilazane treatment using a spin coater Mark8 manufactured by Tokyo Electron. The film was baked at 120 ° C. for 60 seconds to obtain a film having an average film thickness of 300 nm.
The resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). After irradiation, it was baked at 130 ° C. for 60 seconds, developed with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.
The results are shown in Table 3.

〔sensitivity〕
The line width of the obtained pattern was observed with a scanning electron microscope (S-9260, manufactured by Hitachi, Ltd.), and the irradiation energy (μC / cm ² ) when resolving a 0.15 μm line (line: space = 1: 1). ) As sensitivity.

[Profile shape]
The profile of the pattern obtained above was observed with a cross-sectional SEM, and the following three-stage evaluation was performed.
1: When there is no skirt shape and is a rectangle 2: When a slightly skirt shape is observed, but when it is almost a rectangle 3: When it is clearly a skirt shape

  From the results in Table 3, it can be seen that the positive resist composition of the present invention is highly sensitive and has no substrate dependency and excellent profile shape in EB exposure.

<EUV exposure>
Similarly to the patterning by the KrF exposure, a resist solution prepared using the components shown in Table 4 below was applied on a 6-inch SiN (100 nm) wafer subjected to hexamethyldisilazane treatment using a spin coater Mark8 manufactured by Tokyo Electron. The film was baked at 120 ° C. for 60 seconds to obtain a film having an average film thickness of 150 nm. The obtained resist film is exposed using EUV light (wavelength 13 nm: EUVES, manufactured by Risotech Japan Co., Ltd.) while changing the exposure amount by 0.5 mJ in the range of 0 to 20.0 mJ. Baked for a second. Thereafter, development was performed for 60 seconds using an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution, followed by rinsing with water for 30 seconds and drying. The obtained pattern was evaluated by the following method.
The results are shown in Table 4.

〔sensitivity〕
The line width of the obtained pattern was observed with a scanning electron microscope (S-9260, manufactured by Hitachi, Ltd.), and the irradiation energy (mJ / cm ² ) when resolving a 0.10 μm line (line: space = 1: 1). ) As sensitivity. The dissolution rate at each exposure dose was measured to obtain a sensitivity curve.

[Profile shape]
The profile of the pattern obtained above was observed with a cross-sectional SEM, and the following three-stage evaluation was performed.
1: When there is no skirt shape and is a rectangle 2: When a slightly skirt shape is observed, but when it is almost a rectangle 3: When it is clearly a skirt shape

  From the results of Table 4, it can be seen that the positive resist composition of the present invention is highly sensitive and has no substrate dependency and excellent profile shape in EUV exposure.

<ArF exposure>
Shown in Table 5 below,
(N) Compound having at least one nitro group and one acid group: Amount shown in Table 5 below Resin: Amount shown in Table 5 Acid generator: 0.03 g
Basic compound or proton acceptor group-containing compound: 0.003 g
Surfactant: 0.001 g
Was dissolved in 19 g of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether (PGMEA / PGME, mass ratio 8/2), and the resulting solution was microfiltered with a 0.1 μm pore size polyethylene filter to obtain a resist solution. .
However, when the proton acceptor group-containing compound and the basic compound were used in combination, the proton acceptor group-containing compound was 0.0015 g and the basic compound was 0.0015 g.

  The prepared positive resist composition was applied on a 6-inch SiN (100 nm) wafer subjected to hexamethyldisilazane treatment using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 130 ° C. for 60 seconds to 120 nm. The resist film was formed. Using the obtained wafer ArF excimer laser scanner (PAS5500 / 1100, NA0.75 manufactured by ASML), exposure was performed through a 6% halftone mask having a 1: 1 line and space pattern. Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.

〔sensitivity〕
The line width of the obtained pattern was observed with a scanning electron microscope (S-9260, manufactured by Hitachi, Ltd.), and the irradiation energy (mJ / cm ² ) when resolving a 0.12 μm line (line: space = 1: 1). ) As sensitivity.
[Profile shape]
The profile of the pattern obtained above was observed with a cross-sectional SEM, and the following three-stage evaluation was performed.
1: When there is no skirt shape and is a rectangle 2: When a slightly skirt shape is observed, but when it is almost a rectangle 3: When it is clearly a skirt shape

  From the results of Table 5, it can be seen that the positive resist composition of the present invention is highly sensitive and has no substrate dependency even in ArF exposure and is excellent in profile shape.

Claims (11)

  A positive resist composition comprising a compound (N) having at least one nitro group and one acid group.   2. The positive resist composition according to claim 1, wherein the acid group of the compound (N) is a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group or a boronic acid group.   The positive resist composition according to claim 1, wherein the acid group of the compound (N) is a carboxylic acid group or a sulfonic acid group.   The positive resist composition according to claim 1, wherein the compound (N) contains at least one aromatic ring.   The positive resist composition according to claim 4, wherein the compound (N) has a structure in which a nitro group or an acid group is directly bonded to an aromatic ring.   Furthermore, it contains (A) a resin whose solubility in an alkaline developer is increased by the action of an acid, and (B) a compound that generates an acid upon irradiation with actinic rays or radiation. The positive resist composition according to any one of the above. (A) The resin whose solubility in an alkaline developer is increased by the action of an acid contains at least one repeating unit represented by formula (A1) or (A2). The positive resist composition according to any one of the above.

In general formula (A1),
n shows the integer of 0-5. m shows the integer of 0-5. However, m + n ≦ 5.
A ₁ represents a hydrogen atom or a group containing a group that decomposes under the action of an acid, and when there are a plurality of groups, they may be the same or different.
S ₁ represents an arbitrary substituent, and when there are a plurality of S _{1 s} , they may be the same or different.
In general formula (A2),
X is a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyloxy group or aralkyl. Represents a group.
A ₂ represents a group containing a group that decomposes by the action of an acid.   (B) The positive resist composition according to claim 1, wherein the compound that generates an acid upon irradiation with actinic rays or radiation is oxime sulfonate or diazodisulfone.   Furthermore, it contains a compound that has a proton acceptor functional group and generates a compound that is decomposed by irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. The positive resist composition according to claim 1, wherein the positive resist composition is a positive resist composition.   A pattern forming method comprising: forming a resist film with the positive resist composition according to claim 1, exposing and developing the resist film.   The pattern forming method according to claim 10, wherein the resist film is formed on a basic substrate.