JP2008203639A - Positive resist composition, resin and polymerizable compound, and pattern forming method using the 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. <P>SOLUTION: There are provided a resin which has a repeating unit (a) having a group represented by general formula (I) and of which the solubility in an alkali developer is increased by the action of an acid, a compound forming the resin, and the above positive photosensitive composition and a pattern forming method using the same. In the formula, R<SB>1</SB>represents a (n+1)-valent hydrocarbon group; R<SB>2</SB>represents a hydrogen atom or a monovalent organic group, a plurality of symbols R<SB>2</SB>may be the same or different; R<SB>3</SB>represents a monovalent organic group, R<SB>2</SB>and R<SB>3</SB>may be the same or different and may bond to each other to form a cyclic structure; and n represents an integer of ≥1. <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 particularly, 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 radiation such as far ultraviolet light, and reacts with the developer of the active radiation irradiated area and the non-irradiated area by a reaction using this acid as a catalyst. It is a pattern forming material that changes the solubility and forms a pattern on a substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system. On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.

  For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed. As a photoresist composition for an ArF light source, a resin in which an alicyclic hydrocarbon moiety is introduced has been proposed for the purpose of imparting dry etching resistance, but the system is extremely hydrophobic as an adverse effect of the introduction of the alicyclic hydrocarbon moiety. Therefore, it is difficult to develop with a tetramethylammonium hydroxide (hereinafter, TMAH) aqueous solution that has been widely used as a resist developer, and the resist is peeled off from the substrate during development. It can be seen. In response to the hydrophobization of the resist, measures such as mixing an organic solvent such as isopropyl alcohol with the developer have been studied, and although some results are seen, the concern about the swelling of the resist film and the process become complicated. The problem is not necessarily solved.

  It has been found that the performance is improved by including a repeating unit having a hydroxyl group in the resin having the alicyclic hydrocarbon structure. Patent Document 1 (Japanese Patent Laid-Open No. 11-109632) describes a photosensitive material in which a polar group is introduced into an alicyclic functional group, and Patent Document 2 (US Pat. No. 6,388,101B) describes a repeating material having a lactone structure. A resist composition using a resin containing a unit is described, and 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 Pat. 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. When such a fine pattern is formed, it is particularly desired to improve not only the resolving power but also the line edge roughness performance of the line pattern and the pattern collapse.

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-11-109632 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. .

一般式（Ｉ）に於いて、
Ｒ₁はｎ＋１価の炭化水素基を表す。
Ｒ₂、水素原子又は１価の有機基を表す。複数のＲ₂は同一でも異なっていても良く、結合して環状構造を形成していてもよい。
Ｒ₃は１価の有機基を表す。Ｒ₂とＲ₃とが結合して環状構造を形成していてもよい。
ｎは１以上の整数を表す
＜２＞
一般式（Ｉ）で表される基を有する繰り返し単位（ａ）が、下記（ＩＩ）で表される繰り返し単位であることを特徴とする上記＜１＞に記載のポジ型感光性組成物。

一般式（ＩＩ）に於いて、
Ｒ₁はｎ＋１価の炭化水素基を表す。
Ｒ₂は水素原子又は１価の有機基を表す。複数のＲ₂は同一でも異なっていても良く、結合して環状構造を形成していてもよい。
Ｒ₃は１価の有機基を表す。Ｒ₂とＲ₃とが結合して環状構造を形成していてもよい。
ｎは１以上の整数を表す。
Ｒ₄は水素原子、アルキル基又は−ＣＨ₂−Ｏ−Ｒａ₂基を表す。
Ｒａ₂は、水素原子、アルキル基又はアシル基を表す。
＜３＞
一般式（Ｉ）または（ＩＩ）におけるＲ₁が脂環式炭化水素基であることを特徴とする上記＜１＞または＜２＞に記載の記載のポジ型感光性組成物。
＜４＞
下記一般式（ＩＩ）で表される繰り返し単位を有することを特徴とする樹脂。

一般式（ＩＩ）に於いて、
Ｒ₁はｎ＋１価の炭化水素基を示す。
Ｒ₂は水素原子又は１価の有機基を表す。複数のＲ₂は同一でも異なっていても良く、結合して環状構造を形成していてもよい。
Ｒ₃は１価の有機基を表す。Ｒ₂とＲ₃とが結合して環状構造を形成していてもよい。
ｎは１以上の整数を表す。
Ｒ₄は水素原子、アルキル基又は−ＣＨ₂−Ｏ−Ｒａ₂基を表す。
Ｒａ₂は、水素原子、アルキル基又はアシル基を表す。
＜５＞
下記一般式（ＩＩＩ）で表される構造を有することを特徴とする重合性化合物。

一般式（ＩＩＩ）に於いて、
Ｒ₁はｎ＋１価の炭化水素基を表す。
Ｒ₂は水素原子又は１価の有機基を表す。複数のＲ₂は同一でも異なっていても良く、結合して環状構造を形成していてもよい。
Ｒ₃は１価の有機基を表す。Ｒ₂とＲ₃とが結合して環状構造を形成していてもよい。
ｎは１以上の整数を表す。
Ｒ₄は水素原子、アルキル基又は−ＣＨ₂−Ｏ−Ｒａ₂基を表す。
Ｒａ₂は、水素原子、アルキル基又はアシル基を表す。
＜６＞
上記＜１＞〜＜３＞のいずれかに記載のポジ型感光性組成物により、膜を形成し、該膜を露光、現像する工程を含むことを特徴とするパターン形成方法。 The present invention has the following configuration.
<1>
(A) a resin having a repeating unit (a) 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) irradiation with actinic rays or radiation A positive photosensitive composition comprising a compound capable of generating an acid.

In general formula (I),
R ₁ represents an n + 1 valent hydrocarbon group.
R _{2 represents} a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more <2>
The positive photosensitive composition as described in <1> above, wherein the repeating unit (a) having a group represented by the general formula (I) is a repeating unit represented by the following (II).

In general formula (II):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more.
R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.
<3>
The positive photosensitive composition as described in <1> or <2> above, wherein R ₁ in the general formula (I) or (II) is an alicyclic hydrocarbon group.
<4>
A resin having a repeating unit represented by the following general formula (II).

In general formula (II):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more.
R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.
<5>
A polymerizable compound having a structure represented by the following general formula (III):

In general formula (III):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more.
R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.
<6>
A pattern forming method comprising: forming a film from the positive photosensitive composition according to any one of <1> to <3>, and exposing and developing the film.

  According to the present invention, a positive photosensitive composition having excellent line edge roughness and improved pattern collapse even in the formation of a fine pattern of 100 nm or less, a polymerizable compound and a resin used therefor, and a pattern forming method using the same Is provided.

Hereinafter, the compounds used in the present invention will be described in detail.
[1] Resin (A) whose solubility in an alkaline developer is increased by the action of an acid
The resin that is decomposed by the acid used in the positive photosensitive composition of the present invention and has increased solubility in an alkaline developer contains the repeating unit (a) having a structure represented by the general formula (I). .

In general formula (I),
R ₁ represents an n + 1 valent hydrocarbon group.
R _{2 represents} a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more

  In the partial structure represented by the general formula (I), by having an acetal structure (an acetal structure is a structure having two or more oxygen atoms in one or more carbon atoms), the hydrophilicity of the resin is increased by the action of an acid. And the solubility is improved.

  Examples of the repeating unit having the structure of the general formula (I) include (meth) acrylic acid ester derivatives, (meth) acrylamide derivatives, vinyl ether derivatives, olefin derivatives, and styrene derivatives having the structure of the general formula (I). Preferably it is a (meth) acrylic acid ester derivative, More preferably, it is a repeating unit represented by general formula (II).

In general formula (II):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more.
R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.

In the general formulas (I) and (II), the n + 1 valent hydrocarbon group of R ₁ is preferably a hydrocarbon group having 2 or more carbon atoms. It may be a chain hydrocarbon group or an alicyclic hydrocarbon group, and may have a substituent. An alicyclic hydrocarbon group is preferable.

  Preferable chain hydrocarbon group includes an alkyl group, preferably a straight chain or branched alkyl group having 2 to 30 carbon atoms, and may have an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain. Good. Specifically, straight chain such as 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. Examples thereof include branched alkyl groups such as an alkyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, and 2-ethylhexyl group.

  The alicyclic hydrocarbon group includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of monocyclic hydrocarbon groups include cycloalkyl groups having 3 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group, and cycloalkenyl groups having 3 to 12 carbon atoms such as cyclohexenyl group. It is done. Preferable monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferable examples include a cyclopentyl group and a cyclohexyl group.

The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group, and examples of the ring assembly hydrocarbon group include a bicyclohexyl group and a perhydronaphthalenyl group. As the bridged cyclic hydrocarbon ring, for example, bicyclic such as pinane, bornane, norpinane, norbornane, bicyclooctane ring (bicyclo [2.2.2] octane ring, bicyclo [3.2.1] octane ring, etc.) Hydrocarbon rings and tricyclic hydrocarbon rings such as homobredan, adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.1.1 ^2,5 ] undecane ring, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, and tetracyclic hydrocarbon rings such as perhydro-1,4-methano-5,8-methanonaphthalene ring. The bridged cyclic hydrocarbon ring includes a condensed cyclic hydrocarbon ring such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydroindene. A condensed ring in which a plurality of 5- to 8-membered cycloalkane rings such as a phenalene ring are condensed is also included.

Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo [5,2,1,0 ^2,6 ] decanyl group, and the like. More preferable examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

R ₂ represents a hydrogen atom or a monovalent organic group. The monovalent organic group preferably has 1 to 30 carbon atoms, and more preferably 1 to 10 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group. The plurality of organic groups R ₂ may be the same or different and may form a cyclic structure. The alkyl chain may have an oxygen atom, a sulfur atom, or a nitrogen atom.

The monovalent organic group for R ₃ is preferably a hydrocarbon group. The hydrocarbon group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and still more preferably 1 to 15 carbon atoms. The alkyl chain may have an oxygen atom, a sulfur atom, or a nitrogen atom. Preferred hydrocarbon groups include straight chain alkyl groups, branched alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups.
Preferred linear alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-dodecyl, n-tetradecyl, n- Examples of the octadecyl group and preferable branched alkyl group include isopropyl group, isobutyl group, t-butyl group, neopentyl group, and 2-ethylhexyl group.
Preferable cycloalkyl group may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, may be polycyclic, and may have an oxygen atom in the ring. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like. A preferable aryl group may have a substituent, and preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group and a naphthyl group. A preferable aralkyl group may have a substituent, and preferably an aralkyl group having 7 to 20 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, and a naphthylethyl group. Preferred alkenyl groups include groups having a double bond at any position of the alkyl group.

R _{2 s} or R ₂ and R ₃ may be connected to each other to form a ring, and the formed ring is preferably a cycloalkyl having 3 to 20 carbon atoms, may be polycyclic, It may have an oxygen atom. Preferable rings include cycloalkyl having 3 to 12 carbon atoms such as cyclopentane, cyclohexane, cycloheptane and cyclooctane. More preferred are cyclopentane, cyclohexane and cyclohexane having an oxygen atom in the ring. More preferably, a plurality of R ₂ are connected to each other to form a ring, or R ₂ and R ₃ are connected to form a ring.

R ₄ represents a hydrogen atom, an alkyl group (preferably having 1 to 4 carbon atoms) or a group represented by —CH ₂ —O—Ra ₂ . Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. R ₄ is preferably a hydrogen atom or a methyl group.

  Specific examples of the repeating unit represented by formula (II) are shown below.

  The resin (B) used in the present application can be obtained by polymerizing a monomer having the structure of the general formula (III) or copolymerizing another monomer as required.

In general formula (III):
n and R _{1 to} R ₄ have the same meanings as in (II).

  The compound represented by the general formula (III) can be synthesized by applying a general acetal synthesis method to an acrylic ester derivative or a methacrylic ester derivative having a hydroxyl group. For example, it can be synthesized by reacting 3-hydroxy-1-adamantyl methacrylate available from Idemitsu Kosan with dihydropyran under acidic conditions such as p-toluenesulfonic acid.

  Specific examples of the monomer represented by the general formula (III) are shown below.

The resin (B) is a resin having a group capable of decomposing with an acid (hereinafter also referred to as “acid-decomposable group”) in the main chain or side chain of the resin, or both of the main chain and the side chain.
A preferred group that can be decomposed with an acid is a group in which the hydrogen atom of the —COOH group is substituted with a group capable of leaving with an acid.
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.
As a resin (acid-decomposable resin) that decomposes by the action of an acid and increases the solubility in an alkali developer, a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI) is used. A resin containing at least one selected from the group of repeating units having the repeating units represented by the following general formula (II-AB) is preferable.

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{22 to} R ₂₅ Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring. )

In formula (II-AB):
R ₁₁ ′ and R ₁₂ ′ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Z ′ represents an atomic group for forming an alicyclic structure which contains two bonded carbon atoms (C—C) and may have a substituent.

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

In 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) —XA′—R. ₁₇ ′ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent.
Here, R ₅ represents an alkyl group, a cyclic hydrocarbon group, or the following —Y group, which may have a substituent.
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.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring. n represents 0 or 1.
R ₁₇ ′ is —COOH, —COOR ₅ , —CN, a hydroxyl group, an optionally substituted alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or -Y group is represented.
R ₆ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent. The -Y group;

(In the —Y group, R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an optionally substituted alkyl group. A and b represent 1 or 2.)

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

The alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.

  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 substituted 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, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. To express. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

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

  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.

Here, R represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A is a single bond, an alkylene group, a substituted 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. Represents a combination of groups.
Ra represents any group of the above formulas (pI) to (pVI).

The repeating unit represented by the general formula (pA) is most preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.
Specific examples of the repeating unit represented by the general formula (pA) are shown below.

In the general formula (II-AB), R ₁₁ ′ and R ₁₂ ′ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Z ′ represents an atomic group for forming an alicyclic structure which contains two bonded carbon atoms (C—C) and may have a substituent.

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 ′, R ₁₂ ′, and R ₂₁ ′ to R ₃₀ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. It is a linear 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.

  Examples of the further substituent in the above 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 a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.
Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{25 in} the general formulas (pI) to (pVI).

The alicyclic hydrocarbon skeleton 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 the acid-decomposable resin according to the present invention, the acid-decomposable group may be contained in the aforementioned —C (═O) —XA′—R ₁₇ ′ or Z ′ in the general formula (II-AB). May be included as a substituent.
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.

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 and R ₁₃ ′ to R ₁₆ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear chain having 1 to 6 carbon atoms. Or a 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.

Examples of the cyclic 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- List 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. Can do.
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.

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 further substituents in the alkyl group, cyclic 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 a cyclic hydrocarbon group. Can do. 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 cyclic hydrocarbon group include those listed above.

  The divalent linking group of A ′ is selected from the group consisting of an alkylene group, a substituted 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. Single or a combination of two or more groups may be mentioned.

  In the acid-decomposable resin according to the present invention, 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 general formula (pVI), It can contain in at least 1 sort (s) of a repeating unit represented by a formula (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 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 of the present invention can contain a repeating unit having a lactone group in addition to the repeating unit containing the structure 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 general formula (Lc), Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ , and Re ₁ each independently represent a hydrogen atom or an alkyl group that may have a substituent. m and n each independently represents an integer of 0 to 3, and m + n is 2 or more and 6 or less.

In the general formulas (V-1) to (V-5), R _{1b to} R _5b each independently represent a hydrogen atom or an optionally substituted alkyl group, cycloalkyl group, alkoxy group, alkoxy group. A carbonyl group, an alkylsulfonylimino group or an alkenyl group is represented. Two of R _{1b to} R _5b may combine to form a ring.

R _{1 to} Re ₁ alkyl groups in general formula (Lc) and R _{1b to} R _5b alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkyls in general formulas (V-1) to (V-5) Examples of the alkyl group in the sulfonylimino 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 a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. As a preferable substituent which the alkyl group of R _b0 may have, as a preferable substituent which the alkyl group as R _1b in the general formulas (V-1) to (V-5) may have. What was illustrated previously is mentioned.
Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom.
A ′ 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 of the present invention may contain 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 form or a monohydroxy form, and more preferably a dihydroxy form.

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 in} —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.

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

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

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

In the 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 of the present invention has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, resolving power, heat resistance, sensitivity. Various repeating structural units can be contained for the purpose of adjusting the above.

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

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

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

The following are mentioned as a preferable aspect of the acid-decomposable resin of the present invention.
(1) Containing a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) (side chain type)
(2) Containing repeating units represented by general formula (II-AB) (main chain type)
However, in (2), for example, the following can be further mentioned.
(3) A repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type)

In the acid-decomposable resin, the content of the repeating unit having the general formula (I) is preferably 10 to 70 mol%, more preferably 20 to 65 mol%, still more preferably 25 to 50 mol% in all repeating structural units. It is.
In the acid-decomposable resin, 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 mol% in all repeating structural units. is there.
In the acid-decomposable resin, the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pVI) is preferably 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, 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%, still more preferably 20 in all repeating structural units. ˜50 mol%.

In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. 99 mol% with respect to the total number of moles of the repeating structural unit having a partial structure containing the alicyclic hydrocarbon represented by (pVI) and the repeating unit represented by the above 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 used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and 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 the composition of the present invention such as propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, which will be described later, are uniformly dissolved in a solvent, and then inert gas such as nitrogen or 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 repeating structural units represented by the above specific examples may be used singly or in combination.
In the present invention, the resins may be used alone or in combination.

The weight average molecular weight of the resin 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. When the weight average molecular weight is less than 1,000, heat resistance and dry etching resistance are deteriorated, which is not preferable. When the weight average molecular weight exceeds 200,000, developability is deteriorated, and the viscosity is extremely high, so that the film forming property is deteriorated. Produces less favorable results.
The molecular weight distribution is usually 1 to 5, preferably 1 to 4, more preferably 1 to 3. A molecular weight distribution exceeding 5 is not preferable because resolution, resist shape deterioration, roughness of the resist pattern side wall, roughness deterioration, and the like are observed.

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

[2] Compound that generates acid upon irradiation with actinic rays or radiation (component B)
The photosensitive composition of this invention contains the compound which generate | occur | produces an acid by irradiation of actinic light or a 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 decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF4-, PF6-, SbF6-, etc. An organic anion containing a carbon atom is preferred.
Preferable organic anions include organic anions represented by the following formula.

Where
Rc ₁ represents an organic group. Is raised preferably an optionally substituted alkyl group having a carbon number of 1-30 as an organic group in rc _1, an aryl group or a plurality of these, a single _{bond, -O -, - CO 2 -} , - S _{-, - SO 3 -, -} SO 2 N (Rd 1) - can be exemplified linked group a linking group such as.
Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ represent 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 Rb ₁ , and most preferably 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. A perfluoroalkylene group having 2 to 4 carbon atoms is preferred.

The organic group of Rc ₁ and Rc ₃ -Rc ₅ is most 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 as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z1-1), (Z1-2) and (Z1-3) described later.

In addition, the compound which has two or more structures represented by general formula (Z1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (Z1) is at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (Z1) It may be a compound.

  As more preferred (Z1) component, compounds (Z1-1), (Z1-2), and (Z1-3) described below can be exemplified.

Compound (Z1-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (Z1), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group or a part of R ₂₀₁ to R ₂₀₃ may be an aryl group with the remaining being an alkyl group.
Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, and an aryldialkylsulfonium compound.
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, branched or cyclic alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec. -Butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group and the like can be mentioned.
Aryl group R ₂₀₁ to R _203, an alkyl group, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g., carbon number 6 to 14), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, You may have a hydroxyl group and a phenylthio group as a substituent. Preferred substituents are linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl groups having 1 to 4 carbon atoms, It is a C1-C4 alkoxy group. The substituent may be substituted with any one of the three 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 (Z1-2) will be described.
Compound (Z1-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (Z1) 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 2-oxoalkyl group, an alkoxycarbonylmethyl group, an allyl group, or a vinyl group, more preferably a linear, branched, or cyclic 2-oxoalkyl group, An alkoxycarbonylmethyl group, most preferably a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, branched, or cyclic, preferably a linear or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group) and cyclic alkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and preferably includes a group having> C═O at the 2-position of the above alkyl group. it can.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferred examples include an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

  The compound (Z1-3) is a compound represented by the following general formula (Z1-3), and is a compound having a phenacylsulfonium salt structure.

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c represent a hydrogen atom or an alkyl group.
Rx and Ry each independently represents an alkyl group, a 2-oxoalkyl group, an alkoxycarbonylmethyl group, an allyl group, or a vinyl group.
Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.
Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} the general formula (Z1).

The alkyl group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms. Group (for example, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group), C3-C8 cyclic alkyl group (for example, cyclopentyl group, cyclohexyl group) ).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably either a straight chain of R _1c to R _5c, branched, cyclic alkyl group, or a linear, branched or cyclic alkoxy group, more preferably the sum of the carbon atoms of R _5c from R _1c 2 to 15 It is. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _5c .
Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group as R _{1c to} R _5c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

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 formula (ZII), (ZIII), R 204 ~R 207 each independently represents an alkyl group which may have an optionally substituted aryl group or a substituent.
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 linear, branched or cyclic, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group) and cyclic alkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g. having 6 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms ), Halogen atoms, hydroxyl groups, phenylthio groups, and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (I).

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

In general formulas (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted aryl group.
R ₂₀₆ , R ₂₀₇ and R ₂₀₈ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
A represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, or a substituted or unsubstituted arylene group.

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

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, examples of particularly preferable compounds are listed below.

(C) Basic compound The positive resist 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 may be used as long as it does not deteriorate sublimation or resist performance. The basic compound is a component having an action of controlling a diffusion phenomenon in a resist film of an acid generated from an acid generator by exposure and suppressing an undesirable chemical reaction in a non-exposed region. By blending such a basic compound, the storage stability of the photosensitive composition obtained by controlling the diffusion phenomenon of the acid generated from the acid generator upon exposure in the resist film is improved, and the resolution as a resist is improved. In addition to further improvement, it is possible to suppress changes in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to development processing, and a composition having excellent process stability can be obtained.

  As the basic compound, organic amines can be used, for example, primary, secondary, and tertiary aliphatic amines, aromatic amines, heterocyclic amines, and nitrogen-containing compounds having a carboxy group. , Nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide derivatives, imide derivatives 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'- 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 (for example, 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, and nitrogen-containing compounds having a sulfonyl group include 3-pyridinesulfonic acid, pyridinium p-toluenesulfonate, and the like.

  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 base containing a cyano group include 3- (diethylamino) propiononitrile, N, N-bis (2-hydroxyethyl) -3-aminopropiononitrile, and N, N-bis (2-acetoxyethyl). -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-aminopro Methyl onate, 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-tetrahydrofur Furyl-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-methoxyethyl) ) Methyl 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-propyl) -N (Cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (3-formyloxy-1-propyl) aminoacetonitrile, N, N-bis (cyanomethyl) aminoacetonitrile, 1-pyrrolidinepropiononitrile, 1-piperidinepropiononitrile, 4-morpholinepropiononitrile, 1-pyrrolidineacetonitrile, 1-piperidineacetonitrile, 4-morpholineacetonitrile, cyanomethyl 3-diethylaminopropionate, cyanomethyl N, N-bis (2-hydroxyethyl) -3-aminopropionate, N, Cyanomethyl N-bis (2-acetoxyethyl) -3-aminopropionate, cyanomethyl N, N-bis (2-formyloxyethyl) -3-aminopropionate, N, N-bis (2-methoxyethyl) Cyanomethyl 3-aminopropionate, N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionate 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), 1-pyrrolidinepropionate cyanomethyl, 1-piperidinepropionate cyano Examples include methyl, cyanomethyl 4-morpholine propionate, 1-pyrrolidinepropionic acid (2-cyanoethyl), 1-piperidinepropionic acid (2-cyanoethyl), 4-morpholine propionic acid (2-cyanoethyl).

As the nitrogen-containing basic compound, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [ 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- Octyl Amine, 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-hydroxy Phenyl) 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) ether, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tricyclohexylamine such as tricyclohexylamine; aniline N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4 Aromatic amines such as nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,6-diisopropylaniline, polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, Nt-butoxycarbonyldi-n- Octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, N- t-butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-Butoki Carbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-t-butoxycarbonylhexamethylenediamine, 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, N t-butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone , Urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea, imidazole, 4-methyl Imidazoles such as imidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenyl Pyridines such as lysine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine; piperazine, 1- (2- In addition to piperazines such as hydroxyethyl) 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 nitrogen-containing basic compounds can be used alone or in combination of two or more, more preferably in combination of two or more.

The positive resist composition of the present invention preferably further contains an ammonium salt 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 total amount of organic amine and basic ammonium salt is usually 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the solid content of the positive resist composition. If it is less than 0.001% by weight, the effect of adding the above components cannot be obtained. On the other hand, when it exceeds 10% by weight, there is a tendency for the sensitivity to deteriorate and the developability of the non-exposed area to deteriorate.

(D) A dissolution inhibiting compound having a molecular weight of 3000 or less, which decomposes by the action of an acid and increases the solubility in an alkali developer. The photosensitive composition of the present invention decomposes in an alkaline developer by the action of an acid. You may contain the dissolution inhibiting compound (henceforth a "dissolution inhibiting compound") of molecular weight 3000 or less which increases solubility. The dissolution inhibiting compound contains an acid-decomposable group, such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724,355 (1996), in order not to lower the permeability of 220 nm or less. Preferred are alicyclic or aliphatic compounds. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the acid-decomposable resin (B).
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 and more preferably 2 to 20% by mass with respect to the solid content of the photosensitive composition.

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

(E) Fluorine-based and / or silicon-based surfactant The photosensitive composition of the present invention further comprises a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, fluorine atom and It is preferable that one or two or more surfactants containing both silicon atoms are contained.

When the photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development defects can be obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A small resist pattern can be provided.
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 Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.

  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 linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

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

  The amount of 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 photosensitive composition (excluding the solvent). .

(F) Organic solvent The photosensitive composition of the present invention is used by dissolving the above components 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, and butyl acetate. 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 photosensitive composition of the present invention further contains a dye, a plasticizer, a surfactant other than the component (E), a photosensitizer, a compound that promotes solubility in a developer, and the like. be able to.
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.
A preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the resin of the component (B) or the resin of the component (D). When the amount exceeds 50% by mass, the development residue is deteriorated, and a new defect that the pattern is deformed during development is not preferable.

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 the methods described in, for example, JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. 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 may 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 photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
For example, the photosensitive composition is coated on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device by an appropriate coating method such as a spinner or a coater.
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.
Before forming the resist film, an antireflection film may be coated on the substrate in advance.
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, AR-2, AR-3, AR-5 manufactured by Shipley, etc. 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.

  Hereinafter, the present invention will be described by way of examples, but the present invention is not limited thereto.

Synthesis Example 1 (Synthesis of monomer (12))
15 g of dihydroxyadamantyl methacrylate was dissolved in 100 ml of methylene chloride, and 12.0 g of dihydroxypyran and 1.50 g of PPTs were added to this solution. The mixture was stirred under reflux conditions for 5 hours, and then concentrated under reduced pressure. 1N sodium hydroxide solution was added, 150 ml of ethyl acetate was added, and this was washed twice with 100 ml of distilled water and with saturated brine. The organic phase was dried over magnesium sulfate and concentrated to give 18 g of product.
300 MHz- ¹ H-NMR (CDCl3)
δ1.3-2.3 (m, 29H), δ3.45 (m, 2H), δ3.95 (m, 2H), δ4.9 (s, 1H), δ5.9 (s, 1H), δ5 .5 (s, 1H), δ 6.0 (s, 1H)

Synthesis Example 2 (Synthesis of monomer (13))
The synthesis was performed in the same manner as in Synthesis Example 1 except that the starting material was changed from dihydroxyadamantyl methacrylate to hydroxymethacrylate.

Synthesis Example 3 (Synthesis of resin (P1))
Under a nitrogen stream, 2.05 g of pucyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 1.98 g of monomer (P1-1), 0.84 g of monomer (P1-2), 0.50 g of monomer (P1-3), 1.80 g of monomer (P1-4), polymerization initiator V-60 ( Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours with 10 mol% dissolved in 18.5 g of cyclohexanone based on the monomer. 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 / 180 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 3.5 g of Resin (P1). The obtained resin (P1) had a weight average molecular weight of 11850 and a dispersity (Mw / Mn) of 1.78.

Resins (P2) to (P13) and resins (Q1) to (Q3) used in Comparative Examples were also synthesized by the same dropping polymerization method.
Hereinafter, the acid-decomposable resins (P1) to (P13) used in the examples and the structures and composition ratios (molar ratio, from the left of the structural formula) of the resins (Q1) to (Q3) used in the comparative examples, The weight average molecular weight and dispersity are shown.

Examples 1 to 13 and Comparative Examples 1 to 3
<Resist preparation>
The components shown in Table 2 below were dissolved in a 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 resist composition. The prepared positive resist composition was evaluated by the following method, and the results are shown in Table 2.

<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 resist composition immediately after preparation was applied by a spin coater and dried at 115 ° C. for 90 seconds (PB) to form a 200 nm resist film.
This resist 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, heated on a hot plate at 120 ° C. for 90 seconds. (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.

(130 nm line and space)
The exposure amount that reproduces the 1: 1 mask pattern is the optimum exposure amount, and the denser pattern of line and space 1: 1 and the isolated pattern of line and space 1:10 have a finer mask size when exposed at the optimum exposure amount. The line width that resolves the pattern without falling is defined as the limit pattern falling line width. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur.

(Line edge roughness)
Line edge edge roughness (LER) is measured using a length-measuring scanning electron microscope (SEM) to observe an 80 nm line-and-space 1/1 pattern, and the edge in the longitudinal direction of the line pattern is 5 μm. The distance from the reference line that should be measured was measured by 50 points with a length measurement SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. Smaller values indicate better performance

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-based)
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: γ-butyrolactone Is the mass ratio.

  D-1; t-butyl lithocholic acid

  From the results, it is clear that the positive photosensitive composition of the present invention has excellent resolution and good line edge roughness.

Immersion exposure <resist preparation>
The components of Examples 1 to 13 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 resist composition. The prepared positive resist composition was evaluated by the following methods.

<Resolution evaluation>
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied onto a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The prepared positive resist composition was applied thereon and baked at 115 ° C. for 60 seconds to form a 150 nm resist 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), a laser, a diaphragm, a shutter, three reflecting mirrors, and a condenser lens were used, and the wafer was exposed through a prism and an immersion liquid (pure water). The laser wavelength was 193 nm, and a prism that formed a 65 nm line and space pattern was used. Immediately after exposure, the film was heated at 115 ° C. for 90 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38%) for 60 seconds, rinsed with pure water, and spin-dried to obtain a resist pattern obtained by scanning electron microscopy. When observed with Hitachi S-9260, a 65 nm line and space pattern was resolved.
It is apparent that the positive photosensitive composition of the present invention has a good image forming ability even in an exposure method using an immersion liquid.

Claims (6)

(A) a resin having a repeating unit (a) 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) irradiation with actinic rays or radiation A positive photosensitive composition comprising a compound capable of generating an acid.

In general formula (I),
R ₁ represents an n + 1 valent hydrocarbon group.
R _{2 represents} a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more. The positive photosensitive composition according to claim 1, wherein the repeating unit (a) having a group represented by the general formula (I) is a repeating unit represented by the following (II).

In general formula (II):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more.
R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. The positive photosensitive composition according to claim 1 or 2, wherein R ₁ in the general formula (I) or (II) is an alicyclic hydrocarbon group. A resin having a repeating unit represented by the following general formula (II).

In general formula (II):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more.
R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. A polymerizable compound having a structure represented by the following general formula (III):

In general formula (III):
R ₁ represents an n + 1 valent hydrocarbon group.
R ₂ represents a hydrogen atom or a monovalent organic group. A plurality of R ₂ may be the same or different, and may combine to form a cyclic structure.
R ₃ represents a monovalent organic group. R ₂ and R ₃ may combine to form a cyclic structure.
n represents an integer of 1 or more R ₄ represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group.
Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. A pattern forming method comprising a step of forming a film with the positive photosensitive composition according to claim 1, and exposing and developing the film.