JP2007256640A - Positive photosensitive composition and pattern forming method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photosensitive composition excellent in line edge roughness and improved in pattern collapse even in the formation of a fine pattern of ≤100 nm and a pattern forming method using the same, with respect to a positive photosensitive composition for use in the production process of a semiconductor such as an IC, in the production of a circuit substrate of liquid crystal, a thermal head and the like or in other photofabrication processes and a pattern forming method using the same. <P>SOLUTION: The positive photosensitive composition contains (A) a resin which comprises a repeating unit having a group of a specific structure typified by ribonolactone (meth)acrylate and has solubility in an alkali developer increased by the action of an acid and (B) a compound which generates an acid upon irradiation with an actinic ray or radiation. The pattern forming method using the positive photosensitive composition is also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a positive photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication processes, and a pattern forming method using the same. is there. More specifically, the present invention relates to a positive photosensitive 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.

The chemically amplified positive photosensitive composition generates an acid in the exposed area by irradiation with actinic light or radiation such as far ultraviolet light, and non-irradiates the irradiated area with the active light or radiation by a reaction using this acid as a catalyst. This is a pattern forming material that changes the solubility of the part in the developer and forms a pattern on the substrate.
When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.
On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group essentially exhibits a large absorption in the 193 nm region. But it was not enough.
For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed.
Furthermore, it has been found that the performance can be improved by adding a repeating unit having a lactone structure to the resin having the alicyclic hydrocarbon structure. For example, in Patent Document 1 (JP-A-9-73173) and Patent Document 2 (US Pat. No. 6,388,101B), a resin having a repeating unit having a mevalonic lactone structure or a γ-lactone structure is used. Resist compositions are described, and in Patent Document 3 (Japanese Patent Laid-Open No. 2000-159758), Patent Document 4 (Japanese Patent Laid-Open No. 2001-109154), and Patent Document 5 (US Patent No. 2001-26901A). Describes a resist composition using a resin containing a repeating unit having an alicyclic lactone structure.
However, from the viewpoint of overall performance as a resist, it is actually difficult to find an appropriate combination of resin, photoacid generator, additive, solvent, etc. to be used, and the line width is 100 nm or less. In forming such a fine pattern, improvement of line edge roughness and pattern collapse has been demanded.
Here, the line edge roughness means that the resist line pattern and the edge of the substrate interface exhibit irregular shapes in a direction perpendicular to the line direction due to the characteristics of the resist. When this pattern is observed from directly above, the edges appear to be uneven (± several nm to several tens of nm). Since the unevenness is transferred to the substrate by an etching process, if the unevenness is large, an electrical characteristic defect is caused and the yield is lowered.

JP-A-9-73173 US Pat. No. 6,388,101B JP 2000-159758 A JP 2001-109154 A US Patent No. 2001-26901A

  An object of the present invention is to provide a positive photosensitive composition which is excellent in line edge roughness and improved in pattern collapse even in the formation of a fine pattern of 100 nm or less, and a pattern forming method using the same. .

  The present invention is as follows.

(1) (A) a resin having a repeating unit having a group represented by the following general formula (I) and having increased solubility in an alkali developer by the action of an acid; and (B) an acid upon irradiation with actinic rays or radiation. A positive photosensitive composition comprising a compound capable of generating odor.

In general formula (I),
Ring A represents a 5- to 7-membered ring.
L represents a single bond or a divalent linking group.
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.

  (2) The positive photosensitive composition as described in (1), wherein the group represented by the general formula (I) is a group represented by the following general formula (I ′).

In general formula (I ′),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure.

  (3) The positive photosensitive composition as described in (2), wherein the repeating unit having a group represented by the general formula (I ′) is represented by the following general formula (I ″).

In general formula (I ''),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different,
It may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group.

  (4) A resin having a repeating unit represented by the following general formula (I ″).

In general formula (I ''),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group.

  (5) A polymerizable compound represented by the following general formula (I ′ ″).

In the general formula (I ''')
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group.

  (6) A pattern formation comprising a step of forming a photosensitive film from the positive photosensitive composition according to any one of (1) to (3), and exposing and developing the photosensitive film. Method.

  According to the present invention, it is possible to provide a positive photosensitive composition which is excellent in line edge roughness and improved in pattern collapse even in the formation of a fine pattern of 100 nm or less, and a pattern forming method using the same.

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).

[1] (A) Resin whose solubility in an alkaline developer is increased by the action of an acid Resin whose solubility in an alkaline developer is increased by the action of an acid used in the positive photosensitive composition of the present invention (hereinafter referred to as “acid decomposition”) The functional resin (also referred to as “A”) has a repeating unit having a group represented by the following general formula (I).

In general formula (I):
Ring A represents a 5- to 7-membered ring.
L represents a single bond or a divalent linking group.
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.

  In general formula (I), ring A is preferably a 5-membered ring or a 6-membered ring, particularly preferably a 5-membered ring.

  The divalent linking group as L is preferably an alkylene group having 1 to 8 carbon atoms. More preferably, it is C1-C6, More preferably, it is C1-C4, A methylene group, ethylene group, a propylene group, a butylene group etc. are mentioned, A methylene group is especially preferable. A plurality of alkylene groups may be substituted, and examples of the substituent include an alkyl group (preferably having 1 to 10 carbon atoms), an alkoxy group (preferably having 1 to 10 carbon atoms) and the like, and an alkyl group (more preferable). A carbon number of 1 to 5) is particularly preferred.

The monovalent organic group as R ₁ preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and still more preferably 1 to 15 carbon atoms. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkoxy group, an alkoxycarbonylamino group, and a cyano group.
The alkyl group as R ₁ may have a substituent, and is preferably a linear or branched alkyl group having 1 to 30 carbon atoms, and has an oxygen atom, a sulfur atom, and a nitrogen atom in the alkyl chain. It 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. Linear alkyl group, isopropyl group, isobutyl group, t-butyl group,
Examples thereof include branched alkyl groups such as a neopentyl group and 2-ethylhexyl group.
The cycloalkyl group as R ₁ may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, which may be monocyclic or polycyclic and has an oxygen atom in the ring. May be. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group as R ₁ 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 as R ₁ 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. .
Examples of the alkenyl group as R ₁ include a group having a double bond at an arbitrary position of the alkyl group.
The alkoxy group in the alkoxy group and alkoxycarbonylamino group as R ₁ is preferably an alkoxy group having 1 to 30 carbon atoms, for example, methoxy group, ethoxy group, propoxy group, n-butoxy group, pentyloxy group, hexyl. An oxy group, a heptyloxy group, etc. are mentioned.
Examples of further substituents that R ₁ may have include 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), an aryl group ( Preferably 6 to 14 carbon atoms, alkoxy group (preferably 1 to 10 carbon atoms), acyl group (preferably 2 to 20 carbon atoms), acyloxy group (preferably 2 to 10 carbon atoms), alkoxycarbonyl group (preferably Include an aminoacyl group (preferably having a carbon number of 2 to 10). As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the further substituent include an alkyl group (preferably having a carbon number of 1 to 10). As for the aminoacyl group, examples of the further substituent include 1 or 2 alkyl groups (preferably having 1 to 10 carbon atoms).

When two R _{1 s} combine to form a cyclic structure, examples of the group formed by two R ₁ include an alkylene group (preferably a methylene group).
When two R ₁ are bonded to form a cyclic structure, the two R ₁ form an acetal structure (—O—C (Ra) (Rb) —O—) with two oxygen atoms on both sides. It is preferable to do. Thereby, solvent solubility improves. In the formula, Ra and Rb each independently represent a hydrogen atom, an alkyl group (preferably having 1 to 5 carbon atoms), a cycloalkyl group (preferably having 3 to 8 carbon atoms) or an aryl group (preferably a phenyl group). . The alkyl group, cycloalkyl group and aryl group of Ra and Rb may be substituted with a hydroxyl group, a halogen atom (preferably a fluorine atom), a cyano group or the like. Ra and Rb may combine to form a cyclic structure (preferably a cycloalkane structure having 3 to 15 carbon atoms). The cyclic structure formed by combining Ra and Rb may be substituted with a hydroxyl group, a halogen atom (preferably a fluorine atom), a cyano group, or the like.

  The group represented by the general formula (I) is preferably a group represented by the general formula (I ′).

In general formula (I ′),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.

In the general formula (I '), R ₁ is in the formula (I), R ₁ synonymous.

The alkyl group as R ₂ may have a substituent, preferably a linear or branched alkyl group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and an oxygen atom in the alkyl chain. May have a sulfur atom or a nitrogen atom. 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.
When two R ₂ are bonded to form a cyclic structure, examples of the group formed by _two R ₂ include an alkylene group (preferably having 2 to 8 carbon atoms).

  The repeating unit having a group represented by the general formula (I ′) includes (meth) acrylic acid ester derivatives, (meth) acrylamide derivatives, vinyl ether derivatives, olefin derivatives having the group represented by the general formula (I ′). , Styrene derivatives and the like, preferably (meth) acrylic acid ester derivatives, more preferably repeating units represented by the following general formula (I ″).

In general formula (I ''),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group.

R ₁ and R ₂ in the general formula (I ″) have the same meanings as R ₁ and R _{2 in} the general formula (I ′).
The alkyl group of R ₃ is preferably an alkyl group having 1 to 4 carbon atoms and may be substituted with a hydroxyl group, an alkoxy group, an acyloxy group, or the like.

  Specific examples of the repeating unit represented by the general formula (I ″) are shown below, but the present invention is not limited thereto.

In the above specific examples, R ₃ represents a hydrogen atom or an alkyl group, and is preferably a hydrogen atom or a methyl group.

  Examples of the polymerizable compound corresponding to the repeating unit represented by the general formula (I ″) include a polymerizable compound represented by the following general formula (I ″ ″).

In the general formula (I ''')
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group.

R ₁ , R ₂ and R ₃ in the general formula (I ′ ″) have the same meanings as R ₁ , R ₂ and R _{3 in} the general formula (I ″).

The polymerizable compound represented by the general formula (I ′ ″) is a novel compound.
The polymerizable compound represented by the general formula (I ′ ″) can be synthesized by using a general etherification or acetal synthesis method. For example, D-ribonolactone available from Nacalai tex is reacted with an alkyl halide such as iodomethane under basic conditions such as t-butoxy potassium, or a catalytic amount of sulfuric acid is added to a ketone such as acetone for reaction. Subsequently, a polymerizable compound represented by the general formula (I ′ ″) can be obtained by reacting with a methacrylic acid ester derivative such as methacrylic acid chloride in the presence of triethylamine.

  Specific examples of the polymerizable compound represented by the general formula (I ′ ″) are shown below, but the present invention is not limited thereto.

The acid-decomposable resin (A) is a resin having a group (hereinafter also referred to as “acid-decomposable group”) capable of decomposing with an acid in the main chain or side chain of the resin, or in both the main chain and the side chain. is there.
A group preferable as a group capable of decomposing with an acid is a group in which a hydrogen atom of an alkali-soluble group such as a —COOH group or —OH group is substituted with a group capable of leaving with an acid.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
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.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The acid-decomposable resin (A) is a repeating unit having a group having an alicyclic hydrocarbon structure represented by the following general formula (pI) to general formula (pVI) and a repeating unit represented by the following general formula (II-AB). It is preferable to have a repeating unit having at least one alicyclic hydrocarbon structure selected from the units.

In the general formulas (pI) to (pVI),
R ₁₁ represents an alkyl group, and Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom.
R _{12 to} R ₁₆ each independently represents an alkyl group or an alicyclic hydrocarbon group. However, at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or an alicyclic hydrocarbon group. However, at least one of R _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents an alkyl group or an alicyclic hydrocarbon group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or an alicyclic hydrocarbon group. However, 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 general formula (II-AB):
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

  The general formula (II-AB) is more preferably the following general formula (II-A) or general formula (II-B).

In general formulas (II-A) and (II-B),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —X—A′—R. ₁₇ ′ represents an alkyl group or an alicyclic hydrocarbon group. At least two of R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
Wherein, R ₅ represents an alkyl group, an alicyclic hydrocarbon group, or -Y group shown below.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or the following —Y group.
R ₆ represents an alkyl group or an alicyclic hydrocarbon group.
n represents 0 or 1.

  The -Y group;

In the -Y group,
R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an alkyl group.
a and b represent 1 or 2.

In the general formulas (pI) to (pVI), the alkyl group in R _{11 to} R ₂₅ may be substituted or unsubstituted, linear or branched alkyl having 1 to 4 carbon atoms. Groups are preferred. Examples of the alkyl group in R _{11 to} R ₂₅ 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.
As further substituents for the alkyl group, an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, carboxy Group, alkoxycarbonyl group, nitro group and the like.

The alicyclic hydrocarbon group in R _{12 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Preferred examples of the alicyclic hydrocarbon group include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Group, cyclodecanyl group, and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.
Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.

The structures represented by the general formulas (pI) to (pVI) can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.
Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.
As the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI), the hydrogen atom of the carboxyl group is preferably substituted with the structure represented by the general formula (pI) to (PVI). Structure is mentioned.

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI), a repeating unit represented by the following general formula (pA) is preferable.

In the general formula (pA),
R represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). A plurality of R may be the same or different.
A is a single bond, a group selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. The alkylene group may have a substituent Ra represents any group of the above formulas (pI) to (pVI).

  The repeating unit represented by the general formula (pA) is particularly preferably a repeating unit composed of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Hereinafter, although the specific example of the repeating unit shown by general formula (pA) is shown, this invention is not limited to this.

In the general formula (II-AB), examples of the halogen atom in R ₁₁ ′ and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
The alkyl group in R ₁₁ ′ and R ₁₂ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. More preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group. Examples of the further substituent in the alkyl group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, and an acyloxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the acyl group include a formyl group and an acetyl group, and examples of the acyloxy group include an acetoxy group.
The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in the resin, and in particular, a bridged alicyclic ring An atomic group for forming a bridged alicyclic structure forming a repeating unit of the formula hydrocarbon is preferred. Examples of the skeleton of the alicyclic hydrocarbon formed include those similar to the alicyclic hydrocarbon groups of R _{12 to} R _{25 in} the general formulas (pI) to (pVI). The skeleton of the alicyclic structure may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B).

  Among the repeating units having the bridged alicyclic hydrocarbon, the repeating unit represented by the general formula (II-A) or (II-B) is more preferable.

In general formulas (II-A) and (II-B),
Examples of the halogen atom in R ₁₃ ′ to R ₁₆ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
The alkyl group in R ₅ , R ₆ , R ₁₃ ′ to R ₁₆ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a linear chain having 1 to 6 carbon atoms. Or it is a branched alkyl group, More preferably, they are a methyl group, an ethyl group, a propyl group, an isopropyl group, n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
Examples of the alicyclic hydrocarbon group in R ₅ , R ₆ and R ₁₃ ′ to R ₁₆ ′ include a cyclic alkyl group and a bridged hydrocarbon group, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, 2 -Methyl-2-adamantyl group, norbornyl group, boronyl group, isobornyl group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group, etc. be able to.
Examples of the alkoxy group for R ₁₇ ′ include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
Examples of the ring formed by combining at least two of R ₁₃ ′ to R ₁₆ ′ include rings having 5 to 12 carbon atoms such as cyclopentene, cyclohexene, cycloheptane, and cyclooctane.
Further substituents in the alkyl group, alicyclic hydrocarbon group, and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group, an alkyl group, and an alicyclic hydrocarbon group. Etc. can be mentioned. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. Examples of the acyl group include a formyl group and an acetyl group. Examples thereof include an acetoxy group. Examples of the alkyl group and alicyclic hydrocarbon group include those listed above.
As the divalent linking group for A ′, one or two or more selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group And combinations of the groups. The alkylene group may have a substituent.
The alkyl group as R ₂₁ ′ to R ₃₀ ′ in the —Y group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a straight chain having 1 to 6 carbon atoms. A chain or branched alkyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group.

In the repeating unit represented by the general formula (II-AB), (II-A), or (II-B), the acid-decomposable group is the same as the above-described —C (═O) —XA′—R ₁₇ ′. It may be included, or may be included as a substituent for Z ′ in formula (II-AB).
The structure of the acid-decomposable group is represented by —C (═O) —X ₁ —R ₀ .
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ has the same meaning as X above.

  In the acid-decomposable resin (A), the group capable of decomposing by the action of an acid is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI). It can contain in at least 1 sort (s) of a repeating unit represented by (II-AB), and the repeating unit of a postscript copolymerization component.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or the general formula (II-B) are atomic groups for forming an alicyclic structure in the general formula (II-AB). Or it becomes a substituent of the atomic group Z for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-A) or the general formula (II-B) include the following, but the present invention is not limited to these specific examples.

  The acid-decomposable resin (A) can have a repeating unit having a lactone group in addition to the repeating unit having a group represented by the general formula (I). Preferably, it has a repeating unit having a group having a lactone structure represented by any of the following general formula (Lc) or the following general formulas (V-1) to (V-5), and a group having a lactone structure May be directly bonded to the main chain.

In the general formula (Lc),
Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represents a hydrogen atom or an alkyl group.
m and n each independently represents an integer of 0 to 3, and m + n is 2 to 6.
In general formulas (V-1) to (V-5),
R _{1b to} R _5b each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylsulfonylimino group, or an alkenyl group. Two of R _{1b to} R _5b may combine to form a ring.

The alkyl group of Ra _{1 to} Re _{1 in} the general formula (Lc) and the alkyl group, alkoxy group, alkoxycarbonyl group of R _{1b to} R _{5b in} the general formulas (V-1) to (V-5) Examples of the alkyl group in the alkylsulfonylimino group include linear and branched alkyl groups, which may have a substituent.

As the repeating unit having a group having a lactone structure represented by general formula (Lc) or any one of general formulas (V-1) to (V-5), the above general formula (II-A) or (II- B) wherein at least one of R ₁₃ ′ to R ₁₆ ′ has a group represented by general formula (Lc) or general formula (V-1) to (V-5) (for example, R in —COOR ₅ ) ₅ represents a group represented by general formula (Lc) or general formulas (V-1) to (V-5)), or a repeating unit represented by the following general formula (AI).

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom or an alkyl group. The alkyl group for R _b0 may have a substituent.
Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
R _b0 is preferably a hydrogen atom.
A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.
B ₂ represents a group represented by any one of general formula (Lc) and general formulas (V-1) to (V-5).

  Specific examples of the repeating unit having a group having a lactone structure other than the general formula (I) are shown below, but the present invention is not limited thereto.

  The acid-decomposable resin (A) of the present invention may have a repeating unit having a group represented by the following general formula (VII).

In general formula (VII):
R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group.

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

As the repeating unit having a group represented by the general formula (VII), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B) is the above general formula (VII). ) (For example, R _{5 of} —COOR ₅ represents a group represented by the general formula (VII)), or a repeating unit represented by the following general formula (AII). it can.

In general formula (AII):
R ₁ c represents a hydrogen atom or a methyl group.
R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group. _{Two of} R ₂ c to R ₄ c are preferably hydroxyl groups.

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

The acid-decomposable resin (A) of the present invention may have a repeating unit having an alkali-soluble group.
As the alkali-soluble group, a carboxyl group is preferable. Specifically, a repeating unit in which a carboxyl group is directly bonded to a main chain such as a repeating unit of methacrylic acid or acrylic acid, or adamantane-3-carboxylic acid-1- (meth). A repeating unit in which a carboxyl group is bonded to the main chain via an alicyclic linking group, such as acrylate.

  The acid-decomposable resin (A) of the present invention may have a repeating unit represented by the following general formula (VIII).

In general formula (VIII):
Z ₂ represents —O— or —N (R ₄₁ ) —. Here, R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, a haloalkyl group, or —OSO ₂ —R ₄₂ . _R42 represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue.

  Specific examples of the repeating unit represented by the general formula (VIII) include the following [I′-1] to [I′-7], but the present invention is not limited to these specific examples. .

In addition to the above repeating structural units, the acid-decomposable resin (A) of the present invention has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution and heat resistance, which are general necessary properties of resist. Various repeating structural units can be contained for the purpose of adjusting properties, sensitivity, and the like.
Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
Thereby, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.
As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc. can be mentioned.
In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  Each of the repeating units represented by the above specific examples may be used alone or in combination.

  In the acid-decomposable resin (A), the molar ratio of each repeating structural unit is the resist dry etching resistance, the standard developer suitability, the substrate adhesion, the resist profile, and the general required performance of the resist, resolving power and heat resistance. It is appropriately set to adjust the property, sensitivity, etc.

Preferred embodiments of the acid-decomposable resin (A) of the present invention include the following.
(1) What contains the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by general formula (pI)-(pVI) (side chain type).
(2) Those having a repeating unit represented by the general formula (II-AB) (main chain type).
However, in (2), for example, the following can be further mentioned.
(3) Those having a repeating unit represented by formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type).

In the acid-decomposable resin (A), the content of the repeating unit having a group represented by the general formula (I) is preferably 10 to 70 mol%, more preferably 20 to 65 mol% in all repeating structural units, More preferably, it is 25-50 mol%.
In the acid-decomposable resin (A), the content of the repeating unit having an acid-decomposable group is preferably 10 to 70 mol%, more preferably 20 to 65 mol%, still more preferably 25 to 60 in all repeating structural units. Mol%.
In the acid-decomposable resin (A), the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) is 20 to 70 mol% in all repeating structural units. More preferably, it is 24-65 mol%, More preferably, it is 28-60 mol%.
In the acid-decomposable resin (A), the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. Preferably it is 20-50 mol%.
Further, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can be appropriately set according to the performance of the desired resist. Generally, the general formula (pI ) To 99 mol% with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon represented by (pVI) and the repeating unit represented by the general formula (II-AB). The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.
When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The acid-decomposable resin (A) having a repeating unit having a group represented by the general formula (I) is a novel compound.

The acid-decomposable resin (A) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and this is added to a reaction solvent, for example, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, methyl ethyl ketone, methyl isobutyl. Ketones, ketones such as cyclohexanone, and further dissolved in a solvent that dissolves the composition of the present invention such as propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether described later, and then inert gas such as nitrogen and argon Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an atmosphere. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. The reaction temperature is 10 ° C to 150 ° C, preferably 30 ° C to 130 ° C, more preferably 50 ° C to 110 ° C.

The weight average molecular weight of the acid-decomposable resin (A) according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, as a polystyrene-converted value by the GPC method. By setting the weight average molecular weight to 1,000 or more, deterioration of heat resistance and dry etching resistance can be prevented, and by setting the weight average molecular weight to 200,000 or less, developability deteriorates and the viscosity becomes extremely high. It can prevent that film forming property deteriorates.
The dispersity (Mw / Mn) is usually 1 to 5, preferably 1 to 4, more preferably 1 to 3. By setting the degree of dispersion (Mw / Mn) to 5 or less, it is possible to prevent resolution, resist shape deterioration, resist pattern side wall roughness, roughness property deterioration, and the like.

  In the positive resist composition of the present invention, the blending amount of the acid-decomposable resin (A) according to the present invention in the entire composition is preferably 40 to 99.9% by mass, more preferably 50%, based on the total resist solid content. ˜99.9% by mass. In the present invention, the acid-decomposable resin (A) may be used alone or in combination.

[2] (B) Compound that generates acid upon irradiation with actinic ray or radiation The positive photosensitive composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation.
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.
Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.
Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.
Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{— and the} like. An organic anion having a carbon atom is preferable.

  Preferable organic anions include organic anions represented by the following general formula.

In the above general formula,
Rc ₁ represents an organic group.
Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality of these are a single bond, —O—, —CO ₂ —, —S—, —SO. Examples include groups connected by a linking group such as _3— and —SO ₂ N (Rd ₁ ) —. Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group.
Preferred examples of the organic group for Rc ₃ , Rc ₄ and Rc ₅ include the same organic groups as those for Rc ₁ , and particularly preferred is a perfluoroalkyl group having 1 to 4 carbon atoms.
Rc ₃ and Rc ₄ may combine to form a ring.
Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group.

The organic group represented by Rc ₁ and Rc _{3 to} Rc ₅ is particularly preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.

The carbon number of the organic group of the in formula (ZI), R _201, R ₂₀₂ and R ₂₀₃ is generally from 1 to 30, preferably 1 to 20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.
In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

Preferred examples of the (ZI) component include compounds (ZI-1), (ZI-2) and (ZI-3) described below.

Compound (ZI-1) is at least one of R ₂₀₁ to R ₂₀₃ in formula (ZI) is an aryl group, an 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 triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.
The aryl group of the arylsulfonium compound is preferably a phenyl group, a naphthyl group or an indole residue, more preferably a phenyl group or an indole residue. 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 methyl group, ethyl group, propyl group, n-butyl group, sec-butyl. Group, t-butyl group and the like.
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 a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, and a linear, branched or cyclic alkoxy group having 1 to 12 carbon atoms, particularly preferably. They are a C1-C4 alkyl group and a C1-C4 alkoxy group. 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 the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, an alkoxycarbonylmethyl group, Particularly preferred is a linear or branched 2-oxoalkyl group.

The alkyl group as R _{201 to} R ₂₀₃ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, Butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, branched 2-oxoalkyl group is preferably an alkoxycarbonyl methyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cyclic 2-oxoalkyl group.
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and preferably a group having> C═O at the 2-position of the above alkyl group or cycloalkyl group Can be mentioned.
The alkoxy group in the alkoxycarbonylmethyl group as 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), 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.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} 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 as the non-nucleophilic anion of X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _7c may be either linear or branched, and for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms (for example, methyl Group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).
Preferable examples of the cycloalkyl group as R _{1c to} R _7c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably, any one of R _{1c to} R _5c is a linear, branched alkyl group, 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 to 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 as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is preferably a linear, branched 2-oxoalkyl group or alkoxymethyl group.
The cycloalkyl group as R _x and R _y may be the same as the cycloalkyl group as R _1c to R _7c. The cycloalkyl group as R _x and R _y is preferably a cyclic 2-oxoalkyl group.
Examples of the linear, branched, or cyclic 2-oxoalkyl 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 R _{1c to} R _5c .
R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

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

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In the general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₆ , R ₂₀₇ and R _{208 each} represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

  Of the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are more preferable.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, examples of particularly preferable compounds are listed below, but the present invention is not limited thereto.

A photo-acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the photoacid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably, based on the total solid content of the positive photosensitive composition. 1 to 7% by mass.

[3] (C) Basic compound The positive photosensitive composition of the present invention preferably further contains a basic compound. As the basic compound, an organic amine, a basic ammonium salt, a basic sulfonium salt, a basic iodonium salt, or the like is used as long as it does not deteriorate sublimation or resist performance. The basic compound is a component having a function of controlling a diffusion phenomenon of an acid generated from a photoacid generator upon exposure in a resist film and suppressing an undesirable chemical reaction in a non-exposed region. By blending such a basic compound, the storage stability of the positive photosensitive composition obtained by controlling the diffusion phenomenon of the acid generated from the photoacid generator upon exposure in the resist film can be improved. In addition, the resolution of the resist pattern can be further improved, and a change in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to development processing can be suppressed.

  As the basic compound, organic amines can be used. For example, primary, secondary, tertiary aliphatic amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group , Nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, amide derivatives, imide derivatives, basic compounds having a cyano group, and the like.

As aliphatic amines, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert-amylamine, cyclopentylamine, hexylamine, cyclohexylamine, Heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di -Sec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine , Dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepentamine, trimethylamine, triethylamine, tri-n-propylamine , Triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine, tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tri Decylamine, tridodecylamine, tricetylamine, N, N, N ′, N′-tetramethylmethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N N ', N'-tetramethyl-tetraethylenepentamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, benzyldimethylamine, and the like.
Aromatic amines and heterocyclic amines include aniline derivatives such as aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, N, N-dimethyltoluidine, etc.), diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (eg pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4 -Dimethylpyro , 2,5-dimethylpyrrole, N-methylpyrrole, etc.), oxazole derivatives (eg oxazole, isoxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4 -Methyl-2-phenylimidazole, etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.) ), Imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine) Trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4- Pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1-ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, Piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (eg quinoline, 3-quinolinecarbonitrile) Etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives Guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives and the like.
Examples of the nitrogen-containing compound having a carboxy group include aminobenzoic acid, indolecarboxylic acid, amino acid derivatives (eg, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, phenylalanine. , Threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine) and the like.
Examples of the nitrogen-containing compound having a sulfonyl group include 3-pyridinesulfonic acid and pyridinium p-toluenesulfonate.
Examples of the nitrogen-containing compound having a hydroxyl group include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N- Diethylethanolamine, triisopropanolamine, 2,2′-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) ethyl] piperazine, piperidine ethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2 -Hydroxyethyl ) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, 8-hydroxyeurolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2 -Pyrrolidine ethanol, 1-aziridine ethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) isonicotinamide and the like are exemplified.
Examples of amide derivatives include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like.
Examples of imide derivatives include phthalimide, succinimide, maleimide and the like.
Specific examples of the basic compound having a cyano group include 3- (diethylamino) propiononitrile, N, N-bis (2-hydroxyethyl) -3-aminopropiononitrile, N, N-bis (2-acetoxy). Ethyl) -3-aminopropiononitrile, N, N-bis (2-formyloxyethyl) -3-aminopropiononitrile, N, N-bis (2-methoxyethyl) -3-aminopropiononitrile, N , N-bis [2- (methoxymethoxy) ethyl] -3-aminopropiononitrile, methyl N- (2-cyanoethyl) -N- (2-methoxyethyl) -3-aminopropionate, N- (2- Cyanoethyl) -N- (2-hydroxyethyl) -3-aminopropionic acid methyl, N- (2-acetoxyethyl) -N- (2-cyanoethyl) -3- Methyl minopropionate, N- (2-cyanoethyl) -N-ethyl-3-aminopropiononitrile, N- (2-cyanoethyl) -N- (2-hydroxyethyl) -3-aminopropiononitrile, N- (2-acetoxyethyl) -N- (2-cyanoethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- (2-formyloxyethyl) -3-aminopropiononitrile, N- ( 2-cyanoethyl) -N- (2-methoxyethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- [2- (methoxymethoxy) ethyl] -3-aminopropiononitrile, N- (2-Cyanoethyl) -N- (3-hydroxy-1-propyl) -3-aminopropiononitrile, N- (3-acetoxy-1-propyl) N- (2-cyanoethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- (3-formyloxy-1-propyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N-tetrahydrofurfuryl-3-aminopropiononitrile, N, N-bis (2-cyanoethyl) -3-aminopropiononitrile, diethylaminoacetonitrile, N, N-bis (2-hydroxyethyl) aminoacetonitrile, N , N-bis (2-acetoxyethyl) aminoacetonitrile, N, N-bis (2-formyloxyethyl) aminoacetonitrile, N, N-bis (2-methoxyethyl) aminoacetonitrile, N, N-bis [2- (Methoxymethoxy) ethyl] aminoacetonitrile, N-cyanomethyl-N- (2-metho Methyl xethyl) -3-aminopropionate, methyl N-cyanomethyl-N- (2-hydroxyethyl) -3-aminopropionate, methyl N- (2-acetoxyethyl) -N-cyanomethyl-3-aminopropionate, N-cyanomethyl-N- (2-hydroxyethyl) aminoacetonitrile, N- (2-acetoxyethyl) -N- (cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (2-formyloxyethyl) aminoacetonitrile, N- Cyanomethyl-N- (2-methoxyethyl) aminoacetonitrile, N-cyanomethyl-N- [2- (methoxymethoxy) ethyl] aminoacetonitrile, N- (cyanomethyl) -N- (3-hydroxy-1-propyl) aminoacetonitrile N- (3-acetoxy-1-pro ) -N- (cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (3-formyloxy-1-propyl) aminoacetonitrile, N, N-bis (cyanomethyl) aminoacetonitrile, 1-pyrrolidinepropiononitrile, 1- Piperidine propiononitrile, 4-morpholine propiononitrile, 1-pyrrolidine acetonitrile, 1-piperidine acetonitrile, 4-morpholine acetonitrile, cyanomethyl 3-diethylaminopropionate, N, N-bis (2-hydroxyethyl) -3-aminopropion Cyanomethyl acid, cyanomethyl N, N-bis (2-acetoxyethyl) -3-aminopropionate, cyanomethyl N, N-bis (2-formyloxyethyl) -3-aminopropionate, N, N-bis (2- Metoki Ethyl) -3-aminopropionic acid cyanomethyl, N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionic acid cyanomethyl, 3-diethylaminopropionic acid (2-cyanoethyl), N, N-bis (2 -Hydroxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis (2-acetoxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis (2-formyloxyethyl) ) -3-Aminopropionic acid (2-cyanoethyl), N, N-bis (2-methoxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionic acid (2-cyanoethyl), cyanomethyl 1-pyrrolidinepropionate, 1-piperidinepropio Examples thereof include cyanomethyl acid, cyanomethyl 4-morpholine propionate, 1-pyrrolidinepropionic acid (2-cyanoethyl), 1-piperidinepropionic acid (2-cyanoethyl), 4-morpholine propionic acid (2-cyanoethyl).

As the basic compound, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2. 2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidines, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, anilines, hydroxyalkylanilines, 4,4′-diaminodiphenyl ether, pyridinium p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, and tetrabutylammonium lactate, triethylamine, tributylamine, tripentylamine, tri-n-octylamine , Tri-i-octylamine, tris (ethylhexyl) amine, tridecylamine, tridodecylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri -N-
Heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, Hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2 -(3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4 -Hydroxyphenyl) propane, 1,4-bis [1- (4 -Aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ) Tri (cyclo) alkylamines such as ether, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tricyclohexylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2 -Aromatic amines such as methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,6-diisopropylaniline, polyethyleneimine, polyallylamine, 2-dimethylamino Ethylacrylamide polymer, Nt- Toxicarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1 Adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl -1-adamantylamine, Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-t-butoxy Carbonylhexamethylenediamine, N, N′-di-t-butoxycarbonyl-1, 7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di-t -Butoxycarbonyl-1,10-diaminodecane, N, N'-di-t-butoxycarbonyl-1,12-diaminododecane, N, N'-di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide N-methylacetamide, N, N-dimethylacetamide, propionamide, benzene Amide, pyrrolidone, N-methylpyrrolidone, urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n- Imidazoles such as butylthiourea, imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4 -Pyridines such as ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine; Piperazine, 1- (2-hydroxy In addition to piperazines such as ethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1 , 4-diazabicyclo [2.2.2] octane.
Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, 4-hydroxypiperidine, 2,2,6,6-tetramethyl-4-hydroxypiperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, 4 , 4'-diaminodiphenyl ether, triethylamine, tributylamine, tripentylamine, tri-n-octylamine, tris (ethylhexyl) amine, tridodecylamine, N, N-di-hydroxyethylaniline, N-hydroxyethyl-N- Organic amines such as ethylaniline are particularly preferred.

The positive photosensitive composition of the present invention preferably further uses a basic ammonium salt compound as the basic compound. Specific examples of the ammonium salt include the following compounds, but are not limited thereto.
Specifically, ammonium hydroxide, ammonium triflate, ammonium pentaflate, ammonium heptaflate, ammonium nonaflate, ammonium undecaflate, ammonium tridecaflate, ammonium pentadecaflate, ammonium methylcarboxylate, ammonium ethylcarboxylate, Ammonium propyl carboxylate, ammonium butyl carboxylate, ammonium heptyl carboxylate, ammonium hexyl carboxylate, ammonium octyl carboxylate, ammonium nonyl carboxylate, ammonium decyl carboxylate, ammonium undecyl carboxylate, ammonium dodecadecyl carboxylate, ammonium salt Decyl carboxylate, ammonium tetradecyl carboxylate, ammonium pentadecyl carboxylate, ammonium hexadecyl carboxylate, ammonium heptadecyl carboxylate, ammonium octadecyl carboxylate and the like.
Specific examples of ammonium as described above include tetramethylammonium, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, and tetraheptylammonium hydroxide. Methyltrioctylammonium hydroxide, tetraoctylammonium hydroxide, didecyldimethylammonium hydroxide, tetrakisdecylammonium hydroxide, dodecyltrimethylammonium hydroxide, dodecylethyldimethylammonium hydroxide, didodecyldimethylammonium hydroxide, tridodecyl Methylammonium hydroxide, myristyl Tylammonium hydroxide, dimethylditetradecylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octadecyltrimethylammonium hydroxide, dimethyldioctadecylammonium hydroxide, tetraoctadecylammonium hydroxide, diallyldimethylammonium hydroxide, (2-chloroethyl) -Trimethylammonium hydroxide, (2-bromoethyl) trimethylammonium hydroxide, (3-bromopropyl) -trimethylammonium hydroxide, (3-bromopropyl) triethylammonium hydroxide, glycidyltrimethylammonium hydroxide, choline hydroxide, ( R)-(+)-(3-Chloro-2-hydroxypropyl) tri Tylammonium hydroxide, (S)-(−)-(3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (2-aminoethyl) ) -Trimethylammonium hydroxide, hexamethonium hydroxide, decamethonium hydroxide, 1-azoniaproperan hydroxide, petronium hydroxide, 2-chloro-1,3-dimethyl-2-imidazolinium hydroxide, Mention may be made of 3-ethyl-2-methyl-2-thiazolinium hydroxide.
That is, as the ammonium hydroxide, specifically, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, Tetraheptylammonium hydroxide, methyltrioctylammonium hydroxide, tetraoctylammonium hydroxide, didecyldimethylammonium hydroxide, tetrakisdecylammonium hydroxide, dodecyltrimethylammonium hydroxide, dodecylethyldimethylammonium hydroxide, didodecyldimethylammonium hydroxy And tridodecylmethylammonium Droxide, myristylmethylammonium hydroxide, dimethylditetradecylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octadecyltrimethylammonium hydroxide, dimethyldioctadecylammonium hydroxide, tetraoctadecylammonium hydroxide, diallyldimethylammonium hydroxide, (2 -Chloroethyl) -trimethylammonium hydroxide, (2-bromoethyl) trimethylammonium hydroxide, (3-bromopropyl) -trimethylammonium hydroxide, (3-bromopropyl) triethylammonium hydroxide, glycidyltrimethylammonium hydroxide, choline hydroxy (R)-(+)-(3-chloro-2- (Droxypropyl) trimethylammonium hydroxide, (S)-(−)-(3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, ( 2-Aminoethyl) -trimethylammonium hydroxide, hexamethonium hydroxide, decamethonium hydroxide, 1-azoniaproperan hydroxide, petronium hydroxide, 2-chloro-1,3-dimethyl-2-imidazoli Examples thereof include nium hydroxide and 3-ethyl-2-methyl-2-thiazolinium hydroxide.

  The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of solid content of a positive photosensitive composition as a total amount, Preferably it is 0.01-5 mass%. By setting the content to 0.001% by mass to 10% by mass, a sufficient effect can be obtained, and the tendency for the sensitivity to deteriorate and the developability of the non-exposed area to deteriorate can be prevented.

[4] (D) A dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as a “dissolution inhibiting compound”) that is decomposed by the action of an acid to increase the solubility in an alkaline developer.
As a dissolution inhibiting compound having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer, it does not decrease the transmittance of 220 nm or less, and is described in Proceeding of SPIE, 2724,355 (1996) An alicyclic or aliphatic compound having an acid-decomposable group is preferred, such as a cholic acid derivative containing an acid-decomposable group. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the acid-decomposable resin (A).

  The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution inhibiting compound is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, based on the solid content of the positive photosensitive composition.

  Specific examples of the dissolution inhibiting compound are shown below, but the present invention is not limited thereto.

[5] Fluorine-based and / or silicon-based surfactant The positive photosensitive composition of the present invention further comprises a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, fluorine It is preferable that one or two or more surfactants containing both atoms and silicon atoms are contained.
When the positive photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development defects are obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It is possible to provide a resist pattern with less.

Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Japanese Patent No. 5405720, No. 5
The surfactants described in JP-A-360692, JP-A-5529881, JP-A-5296330, JP-A-53466098, JP-A-5576143, JP-A-5294511, and JP-A-5824451 can be exemplified. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).
Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of fluorine and / or silicon 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 photosensitive composition (excluding the solvent). It is.

[6] Organic solvent The positive photosensitive composition of the present invention is used by dissolving each component in a predetermined organic solvent.
Examples of the organic solvent that can be used 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, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but a solvent containing a hydroxyl group in the structure, a solvent containing an ester or lactone structure in the structure, and a ketone structure in the structure. It is preferable to use a mixed solvent obtained by mixing two or more selected from the solvents to be contained. Thereby, the generation of particles during storage of the resist solution can be reduced.
Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.
Examples of the solvent containing an ester or lactone structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, γ-butyrolactone, butyl acetate and the like. Among these, propylene glycol monomethyl ether acetate, ethyl Ethoxypropionate is particularly preferred, and propylene glycol monomethyl ether acetate is most preferred.
Examples of the solvent containing a ketone structure include 2-heptanone and cyclohexanone, with cyclohexanone being preferred.
A preferable combination of the mixed solvents is a combination of a solvent containing a hydroxyl group and a solvent containing an ester structure, or a combination of a solvent containing a ketone structure and a solvent containing an ester structure.

<Other additives>
If necessary, the positive photosensitive composition of the present invention further has solubility in dyes, plasticizers, surfactants other than the above-mentioned fluorine-based and / or silicon-based surfactants, photosensitizers, and developers. The compound etc. which promote can be contained.

The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.
The preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, more preferably 5 to 30% by mass with respect to the acid-decomposable resin (A). By setting the amount to 50% by mass or less, it is possible to prevent the development residue from being deteriorated and the pattern from being deformed during development.
Such a phenol compound having a molecular weight of 1000 or less can be easily synthesized by those skilled in the art with reference to methods described in, for example, JP-A-4-1222938, JP-A-2-28531, US Pat. can do.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

In the present invention, a surfactant other than the fluorine-based and / or silicon-based surfactant can be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.
These surfactants may be added alone or in some combination.

(how to use)
The positive photosensitive composition of the present invention is used by dissolving each component in a predetermined organic solvent, preferably the mixed solvent, and applying the solution onto a predetermined support as follows.
For example, a positive photosensitive composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by an appropriate application method such as a spinner or a coater, and a photosensitive film is formed. Form.
After the application, actinic rays and radiation are irradiated through a predetermined mask, followed by baking and development. In this way, a good pattern can be obtained. Examples of the actinic ray include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, specifically Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc., ArF excimer laser and F ₂ excimer laser are most preferable. In the present invention, X-rays and electron beams are also included in the actinic rays.

  Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. Further, an overcoat layer may be further provided on the photosensitive film so that the immersion medium and the resist film do not come into direct contact during immersion exposure. Thereby, elution of the composition from the resist film to the immersion medium is suppressed, and development defects are reduced.

Before forming the photosensitive film, an antireflection film can be applied in advance on the substrate.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, and AR-2, AR-3, AR-5 manufactured by Shipley may be used. it can.

In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

Synthesis Example 1 (Synthesis of polymerizable compound (5))
25 g of D-(+)-ribonolactone was dissolved in 800 ml of acetone, and 18 ml of concentrated sulfuric acid was added dropwise to this solution under ice cooling. After reacting at room temperature for 4 hours, 50 g of sodium hydrogen carbonate was added for neutralization. Excess sodium bicarbonate was removed by filtration. The organic phase was dried over magnesium sulfate and concentrated to give the crude product. This was recrystallized from hexane to obtain 22.1 g of an acetal compound.
22 g of the obtained acetal compound was dissolved in 230 ml of tetrahydrofuran, and 32.4 ml of triethylamine was added thereto. 26 ml of methacrylic anhydride was added dropwise under ice cooling. The mixture was reacted at room temperature for 3.5 hours, and 200 ml of ethyl acetate was added thereto. The organic layer was washed with water, dried and concentrated to obtain a crude product. This was recrystallized from hexane to obtain 10.6 g of a polymerizable compound (5).
300 MHz- ¹ H-NMR (CDCl3)
δ1.3 (s, 3H), δ1.35 (s, 3H), δ1.9 (s, 3H), δ4.3 (s, 2H), δ5.8 (s, 1H), δ6.0 (s 1H)

Synthesis Example 2 (Synthesis of polymerizable compound (12))
20 g of D-(+)-ribonolactone was dissolved in 120 ml of cyclohexanone, and 2.4 ml of concentrated sulfuric acid was added dropwise to this solution under ice cooling. After reacting at room temperature for 4 hours, 20 g of sodium hydrogen carbonate was added for neutralization. Excess sodium bicarbonate was removed by filtration. 150 ml of ethyl acetate was added to the filtrate, and this was washed twice with distilled water and once with saturated brine. The organic phase was dried over magnesium sulfate and concentrated to give the crude product. This was recrystallized from hexane to obtain 33.5 g of an acetal compound.
33 g of the obtained acetal compound was dissolved in 320 ml of tetrahydrofuran, and 40.7 ml of triethylamine was added thereto. 33 ml of methacrylic anhydride was added dropwise under ice cooling. The mixture was reacted at room temperature for 3.5 hours, and 200 ml of ethyl acetate was added thereto. The organic layer was washed with water, dried and concentrated to obtain a crude product. This was recrystallized from hexane to obtain 17.1 g of a polymerizable compound (12).
300 MHz- ¹ H-NMR (CDCl3)
δ1.3-1.8 (m, 10H), δ1.9 (s, 3H), δ4.4 (s, 2H), δ4.7 (s, 1H), δ4.8 (s, 1H), δ5 .9 (s, 1H), δ 5.7 (s, 1H), δ 6.1 (s, 1H)

  Thereafter, other polymerizable compounds were synthesized in the same manner.

Synthesis Example 3 (Synthesis of Resin (P-1))
Under a nitrogen stream, propylene glycol monomethyl ether acetate 1.23 g and propylene glycol monomethyl ether 0.82 g were placed in a three-necked flask and heated to 80 ° C. To this, 2.37 g of the polymerizable compound (12), 1.01 g of dihydroxyadamantane methacrylate, 1.57 g of isoadamantyl methacrylate, 0.17 g of methacrylic acid, 11.1 g of propylene glycol monomethyl ether acetate, polymerization initiator V-601 (sum) A product obtained by dissolving 6 mol% of Kopure Pharmaceutical Co., Ltd. in 7.38 g of propylene glycol monomethyl ether with respect to the monomer was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then poured into 270 ml of hexane / 30 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 3.9 g of Resin (P-1). The obtained resin (P-1) had a weight average molecular weight of 8760 and a dispersity (Mw / Mn) of 2.10.

  Resins (P-2) to (P-20) used in Examples and Resins (Q1) and (Q2) used in Comparative Examples were also synthesized by the same dropping polymerization method.

  Hereinafter, the structures of the resins (P-1) to (P-20) and the resins (Q1) and (Q2) are shown. The numerical value of the repeating unit represents a molar ratio.

  Table 1 below shows the weight average molecular weights and dispersities of the resins (P-1) to (P-20) and the resins (Q1) and (Q2).

Examples 1-14 and Comparative Examples 1-2
<Resist preparation>
The components shown in Table 2 below were dissolved in an organic solvent to prepare a solution having a solid content concentration of 8% by mass, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive photosensitive composition. The prepared positive photosensitive composition was evaluated by the following method, and the results are shown in Table 2.

  Hereinafter, the abbreviations in Table 2 are as follows.

N-1: trioctylamine N-2: 2,6-diisopropylaniline N-3: N-phenyldiethanolamine N-4: diazabicyclo [4.3.0] nonene N-5: dicyclohexylmethylamine N-6: 2 , 4,5-Triphenylimidazole N-7: 4-dimethylaminopyridine

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

SL-1: cyclohexanone SL-2; propylene glycol monomethyl ether acetate SL-3: ethyl lactate SL-4: propylene glycol monomethyl ether SL-5: δ-butyrolactone In Table 2, when a plurality of organic solvents are used The ratio is a mass ratio.

D-1; t-butyl lithocholic acid

<Resist evaluation>
ARC29A manufactured by Brewer Science Co., Ltd. was uniformly applied to a silicon wafer with a spin coater at 78 nm, and heat-dried at 205 ° C. for 60 seconds to form an antireflection film. Thereafter, each positive photosensitive composition immediately after preparation was applied by a spin coater and dried (PB) at 115 ° C. for 90 seconds to form a 200 nm photosensitive film.
This photosensitive film is exposed with an ArF excimer laser stepper (PAS5500 / 1100 NA = 0.75 (2/3 annular illumination) manufactured by ASML) through a mask, and immediately after exposure on a hot plate at 120 ° C. for 90 seconds. Heated (PEB). Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a resist pattern.
Pattern collapse:
When the line width of the line pattern formed by increasing the exposure amount from the optimal exposure amount is reduced to the optimal exposure amount, the exposure amount for reproducing the 80 nm line and space 1: 1 mask pattern Defined with line width that resolves without falling down. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur and the resolution is higher.
Line edge roughness:
The line edge edge roughness is measured by using a length-measuring scanning electron microscope (SEM) to observe a line-and-space 1/1 pattern of 80 nm, and the edge of the line pattern in the longitudinal direction should have an edge of 5 μm. The distance from the reference line was measured by 50 points using a length measurement SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. Smaller values indicate better performance

  From Table 2, it is clear that the positive photosensitive composition of the present invention has improved pattern collapse and line edge roughness.

Immersion exposure <Resist preparation>
The components of Examples 1 to 14 were dissolved in a solvent to prepare a solution having a solid content concentration of 7% by mass, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive photosensitive composition. The prepared positive photosensitive composition was evaluated by the following methods.
<Resolution evaluation>
An organic antireflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) is applied on a silicon wafer.
An antireflection film having a thickness of 78 nm was formed by baking at 60 ° C. for 60 seconds. The prepared positive photosensitive composition was applied thereon and baked at 115 ° C. for 60 seconds to form a 150 nm photosensitive film. The wafer thus obtained was subjected to two-beam interference exposure (wet exposure) using pure water as the immersion liquid. In the two-beam interference exposure (wet), as shown in FIG. 1, a laser 1, an aperture 2, a shutter 3, three reflecting mirrors 4, 5, 6 and a condenser lens 7 are used, and a prism 8, an immersion liquid is used. The wafer 10 having an antireflection film and a resist film was exposed through (pure water) 9. The wavelength of the laser 1 was 193 nm, and the prism 8 forming a 65 nm line and space pattern was used. Immediately after the exposure, the resist pattern obtained by heating at 115 ° C. for 90 seconds, developing with an aqueous tetramethylammonium hydroxide solution (2.38%) for 60 seconds, rinsing with pure water, and spin drying is then applied to a scanning electron microscope. (Hitachi S-9260) was used for observation. When the positive photosensitive compositions of Examples 1 to 14 were used, a 65 nm line and space pattern was resolved without causing pattern collapse.
It is clear that the positive photosensitive composition of the present invention has a good image forming ability even in an exposure method using an immersion liquid.

It is the schematic of a two-beam interference exposure experiment apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser 2 Aperture 3 Shutter 4, 5, 6 Reflection mirror 7 Condensing lens 8 Prism 9 Immersion liquid 10 Wafer having antireflection film and resist film 11 Wafer stage

Claims (6)

(A) A resin having a repeating unit having a group represented by the following general formula (I), which increases the solubility in an alkali developer by the action of an acid, and (B) generates an acid upon irradiation with actinic rays or radiation. A positive photosensitive composition comprising a compound.

In general formula (I),
Ring A represents a 5- to 7-membered ring.
L represents a single bond or a divalent linking group.
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure. The positive photosensitive composition according to claim 1, wherein the group represented by the general formula (I) is a group represented by the following general formula (I ').

In general formula (I ′),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure. The positive photosensitive composition according to claim 2, wherein the repeating unit having a group represented by the general formula (I ′) is represented by the following general formula (I ″).

In general formula (I ''),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group. A resin having a repeating unit represented by the following general formula (I ″).

In general formula (I ''),
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group. A polymerizable compound represented by the following general formula (I ′ ″).

In the general formula (I ''')
R ₁ represents a hydrogen atom or a monovalent organic group. Two R _{1 s} may be the same or different and may combine to form a cyclic structure.
R ₂ represents a hydrogen atom or an alkyl group. Two R _{2 s} may be the same or different and may combine to form a cyclic structure.
R ₃ represents a hydrogen atom or an alkyl group.   A pattern forming method comprising a step of forming a photosensitive film from the positive photosensitive composition according to claim 1, and exposing and developing the photosensitive film.

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