JP4580794B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive resist composition suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photo-publishing processes, and a pattern forming method using the same. More specifically, the present invention relates to a positive resist composition capable of forming a highly refined pattern, particularly using an electron beam, X-ray, EUV light, and the like, and a pattern forming method using the same. The present invention relates to a positive resist composition that can be suitably used for microfabrication of a semiconductor element using energy rays, and a pattern forming method using the same.

  Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a resist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Along with this, there is a tendency for the exposure wavelength to be shortened from g-line to i-line, and further to KrF excimer laser light. In addition to the excimer laser light, lithography using electron beams, X-rays, or EUV light is also being developed.

  As a resist suitable for a lithography process using such an electron beam, X-ray or EUV light, a chemically amplified resist using an acid catalyst reaction is mainly used from the viewpoint of high sensitivity. As a main component, a chemically amplified composition comprising a polymer and an acid generator, which are insoluble or hardly soluble in an alkaline aqueous solution and soluble in an alkaline aqueous solution by the action of an acid, is effectively used.

  Regarding positive resists for EUV light, Non-Patent Document 1 (KE Gosalves, Adv, Mater, 13, 195, 2001), Non-Patent Document 2 (KE Gosalves, Microelectron. Eng, 65, 454, 2003) ) Discloses a sulfonium salt pendant binder that generates a triflate having 1 carbon atom.

However, even with the above technique, the high resolution, line edge roughness, and PED characteristics in vacuum are not satisfied at the same time.
Line edge roughness means that due to the characteristics of the resist composition, the line pattern of the resist composition and the edge of the substrate interface exhibit a shape that varies irregularly in a direction perpendicular to the line direction. When this pattern is observed from directly above, the edges appear to be uneven (approximately ± several tens of nm). Since the unevenness is transferred to the substrate by the etching process, if the unevenness is large, an electrical characteristic defect is caused and the yield is reduced. As the resist pattern size becomes less than quarter micron, there is an increasing demand for improving line edge roughness.
In addition, pattern line width stability (PED in vacuum) at the occurrence of exposure after exposure in vacuum is a very important performance when performing exposure in a vacuum such as an electron beam or X-ray. If the characteristics are poor, the performance of the electron beam or X-ray drawing changes greatly between the initial stage of drawing and the end of drawing. As a result, the in-plane uniformity of the line width of the drawn pattern varies greatly, and the yield is remarkable. It will cause a decline.
Further, the above-mentioned line edge roughness also has a problem that it is deteriorated by holding in a vacuum.
Further, when EUV is used as a light source, the wavelength of light belongs to the extreme ultraviolet region and has high energy, and thus there has been a problem such as a decrease in contrast due to concerted photochemical reactions such as negation due to EUV light.
It is difficult to combine a sufficiently good line edge roughness under electron beam or X-ray irradiation with a good vacuum PED characteristic (line width fluctuation, line edge roughness fluctuation) in a combination of conventionally known techniques. Both of these have been desired. Further, it has been desired to have sufficiently good sensitivity and contrast even under EUV irradiation.

K. E. Gonzalves, Adv, Mater, 13, 195, 2001 K. E. Gonsalves, Microelectron. Eng, 65, 454, 2003

  An object of the present invention is to solve the problems of performance improvement technology in microfabrication of a semiconductor device using a high energy beam, particularly an electron beam, X-ray or EUV light. The resolution, PED characteristics in vacuum, line edge roughness Another object of the present invention is to provide a positive resist composition which satisfies development defects and outgas at the same time, and is particularly excellent in sensitivity and dissolution contrast when using EUV light.

  The present invention is as follows.

(1) (A) At least one repeating unit selected from the repeating unit represented by the following general formula (A1) and the repeating unit represented by the general formula (A2), and arylsulfone by irradiation with actinic rays or radiation and a repeating unit having a sulfonium salt structure capable of generating an acid, the resin exhibits increased solubility in an alkaline developer under the action of an acid and,
(B) a compound different from the resin (A) that generates sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine by irradiation with actinic rays or radiation ,
A positive resist composition comprising:

In general formula (A1),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, an alkoxy group or an acyloxy group.
A ₁ represents a group that is decomposed by the action of an acid.
n represents 0-4.
In general formula (A2),
Ra represents a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, a chloro atom, a hydroxymethyl group or an alkoxymethyl group.
L represents a divalent linking group.
Rd represents a group that decomposes by the action of an acid.

  (2) The repeating unit having a sulfonium salt structure that generates an arylsulfonic acid upon irradiation with actinic rays or radiation in the resin of component (A) is represented by the following general formula (A3) (1) ) Positive resist composition.

In general formula (A3),
Ra represents a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, a chloro atom, a hydroxymethyl group or an alkoxymethyl group.
L ₁ represents a divalent linking group.
Ar ₁ and Ar ₂ each independently represent a monovalent aromatic ring. Ar ₁ and Ar ₂ may be linked to form a ring.
Ar ₃ represents a divalent aromatic ring.
A represents an aryl sulfonate anion.

一般式（ｐＩＩ）に於いて、
Ｒ ₁₂ 〜Ｒ ₁₄ は、各々独立に、炭素数１〜４個の直鎖もしくは分岐のアルキル基、又は、脂環式炭化水素基を表し、Ｒ ₁₂ 〜Ｒ ₁₄ のうち少なくとも１つは脂環式炭化水素基である。
（５）
樹脂（Ａ）が下記一般式（ＡＩ）で表される繰り返し単位を有することを特徴とする（１）〜（４）のいずれかに記載のポジ型レジスト組成物。

一般式（ＡＩ）中、
Ｒb ₀ は、水素原子、ハロゲン原子、又は炭素数１〜４のアルキル基を表す。
Ａbは、アルキレン基、単環または多環の脂環炭化水素構造を有する２価の連結基、単結合、エーテル基、エステル基、カルボニル基、カルボキシル基、又はこれらを組み合わせた２価の基を表す。
Ｖは一般式（ＬＣ１−１）〜（ＬＣ１−１２）のうち、いずれかで示される基を表す。

Ｒｂ ₃ は置換基を表す。
ｎ ₂ は、０〜４の整数を表す。ｎ ₂ が２以上の時、複数存在するＲｂ ₃ は、同一でも異なっていてもよく、また、複数存在するＲｂ ₃ 同士が結合して環を形成してもよい。
（６）
樹脂（Ａ）が下記１〜１６の少なくとも１つで表されるモノマー由来の繰り返し単位を有する樹脂であることを特徴とする上記（１）〜（５）のいずれかに記載のポジ型レジスト組成物。

（７） 化合物（Ｂ）が、下記一般式（ＺＩ）〜（ＺＶＩ）で表される化合物であることを特徴とする上記（１）〜（６）のいずれかに記載のポジ型レジスト組成物。

上記一般式（ＺＩ）に於いて、
Ｒ ₂₀₁ 、Ｒ ₂₀₂ 及びＲ ₂₀₃ は、各々独立に、炭素数１−３０の有機基を表す。
Ｒ ₂₀₄ 〜Ｒ ₂₀₇ は、各々独立に、アリール基、アルキル基又はシクロアルキル基を表す。
Ｘ ^- は、下記一般式に示すスルホン酸アニオン、ビス（アルキルスルホニル）アミドアニオン、トリス（アルキルスルホニル）メチンアニオンの何れかを表す。

Ｒｃ ₁ は、炭素数１−３０の有機基を表す。
Ｒｃ ₃ 、Ｒｃ ₄ 及びＲｃ ₅ は、各々独立に、炭素数１−３０の有機基を表す。Ｒｃ ₃ とＲｃ ₄ が結合して環を形成していてもよい。

一般式（ＺＩＶ）〜（ＺＶＩ）中、
Ａｒ ₃ 及びＡｒ ₄ は、各々独立に、アリール基を表す。
Ｒ ₂₀₆ 、Ｒ ₂₀₇ 及びＲ ₂₀₈ は、各々独立に、アルキル基又はアリール基を表す。
Ａは、アルキレン基、アルケニレン基又はアリーレン基を表す。 (3) The resin (A) has a repeating unit represented by the general formula (A1), and in the repeating unit represented by the general formula (A1), A ₁ is a group having a cyclic carbon structure. The positive resist composition as described in (1) or (2) above.
(4) The resin (A) has a repeating unit represented by the general formula (A2), and in the repeating unit represented by the general formula (A2), Rd is represented by the following general formula (pII). The positive resist composition as described in any one of (1) to (3), wherein the positive resist composition is a group.

In general formula (pII):
R _{12 to} R ₁₄ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, and at least one of R _{12 to} R ₁₄ is an alicyclic ring. It is a formula hydrocarbon group.
(5)
Resin (A) has a repeating unit represented by the following general formula (AI), The positive resist composition in any one of (1)-(4) characterized by the above-mentioned.

In general formula (AI),
Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Ab is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express.
V represents a group represented by any one of the general formulas (LC1-1) to (LC1-12).

Rb ₃ represents a substituent.
n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of Rb ₃ may be the same or different, and a plurality of Rb ₃ may be bonded to form a ring.
(6)
The positive resist composition as described in any one of (1) to (5) above, wherein the resin (A) is a resin having a repeating unit derived from a monomer represented by at least one of the following 1 to 16: object.

(7) The positive resist composition as described in any one of (1) to (6) above, wherein the compound (B) is a compound represented by the following general formulas (ZI) to (ZVI): .

In the above general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group having 1 to 30 carbon atoms.
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
X ⁻ represents any one of a sulfonate anion, a bis (alkylsulfonyl) amide anion, and a tris (alkylsulfonyl) methine anion represented by the following general formula.

Rc ₁ represents an organic group having _{1 to} 30 carbon atoms.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group having 1 to 30 carbon atoms. Rc ₃ and Rc ₄ may combine to form a ring.

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

( 8 ) A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of (1) to ( 7 ); and then subjecting the resist film to immersion exposure and development.

( 9 ) After forming a resist film with the positive resist composition according to any one of (1) to ( 7 ), the resist film is exposed and developed with EUV light or an electron beam, and then pattern formation is provided. Method.

  According to the present invention, a positive resist composition which simultaneously satisfies resolution, PED characteristics in vacuum, line edge roughness, development defect, and outgas, particularly excellent sensitivity and dissolution contrast when using EUV light, and a pattern forming method using the same Can be provided.

Hereinafter, the present invention will be described in detail.
The present invention is an invention having the configuration described in the claims, but other matters are also described for reference.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, an “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group),
An alkyl group having a substituent (substituted alkyl group) is also included.

[1] (A) At least one type of repeating unit selected from the repeating unit represented by formula (A1) and the repeating unit represented by formula (A2), and arylsulfonic acid by irradiation with actinic rays or radiation A resin having a repeating unit having a sulfonium salt structure that generates an acid, and having increased solubility in an alkaline developer by the action of an acid. The positive resist composition of the present invention is represented by the following general formula (A1) Having at least one repeating unit selected from the repeating unit and the repeating unit represented by formula (A2), and a repeating unit having a sulfonium salt structure that generates an arylsulfonic acid upon irradiation with actinic rays or radiation, It contains a resin (hereinafter also referred to as “acid-decomposable resin”) whose solubility in an alkaline developer is increased by the action of an acid.

In general formula (A1),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, an alkoxy group or an acyloxy group.
A ₁ represents a group that is decomposed by the action of an acid.
n represents 0-4.
In general formula (A2),
Ra represents a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, a chloro atom, a hydroxymethyl group or an alkoxymethyl group.
L represents a divalent linking group.
Rd represents a group that decomposes by the action of an acid.

In the general formula (A1), the group decomposed by the action of the acid A ₁ is represented by the following general formula (PI) or (PII) in addition to the t-butoxycarbonyl group and the t-butoxycarbonylmethyl group. Group.
In the repeating unit represented by the general formula (A1), a group capable of decomposing by the action of the acid A ₁ is decomposed to form a hydrophilic group, and the solubility in an alkali developer is increased.

In general formulas (PI) and (PII):
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. In addition, it is preferable that at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ is an alicyclic hydrocarbon group.

  Among the repeating units represented by the general formula (A1), preferred repeating units include those represented by the following general formula (I).

In general formula (I),
L ₁ and L ₂ may be the same or different and each represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, or an aralkyl group.
Za represents a linear or branched alkyl group, a cycloalkyl group, or an aralkyl group.
Za and L ₁ may combine with each other to form a 5- or 6-membered ring.
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, an alkoxy group or an acyloxy group.
n represents 0-4.

In general formula (I), the alkyl groups of L ₁ , L ₂ and Za are methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, Examples thereof include straight-chain or branched ones having 1 to 20 carbon atoms such as octyl group and dodecyl group. These groups may have a substituent.
Examples of the cycloalkyl group of L ₁ , L ₂ and Za include those having 3 to 20 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group. These groups may have a substituent.

Preferred substituents that the alkyl group and cycloalkyl group of L ₁ , L ₂ and Za may have include an alkyl group, an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acyloxy group, an acylamino group, and a sulfonylamino group. , An alkylthio group, an arylthio group, an aralkylthio group, a thiophenecarbonyloxy group, a thiophenemethylcarbonyloxy group, a heterocyclic residue such as a pyrrolidone residue, and the like, preferably having 12 or less carbon atoms.

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

  The alkyl group and cycloalkyl group in these groups may further have a substituent such as the aforementioned alkyl group, cycloalkyl group, or alkoxy group.

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

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

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

In the general formula (I), examples of the aralkyl groups of L ₁ , L ₂ and Za include those having 7 to 15 carbon atoms such as benzyl group and phenethyl group. These groups may have a substituent.

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

Examples of the 5- or 6-membered ring formed by bonding Za and L ₁ to each other include a tetrahydropyran ring and a tetrahydrofuran ring.

In the present invention, Za is preferably a group having a cyclic carbon structure such as an alicyclic group or an aromatic group.
Here, as an alicyclic group, a C5-C12 thing, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecanyl group, is preferable. Moreover, as an aromatic group, those having 6 to 16 carbon atoms such as a phenyl group and a naphthyl group are preferable, and these groups further have a substituent such as a methylphenyl group and an ethylphenyl group. It may be.

  The acid-decomposable monomer (a) corresponding to the repeating unit represented by the general formula (I) is, for example, a monomer having a phenolic hydroxyl group, preferably dissolved in an organic solvent, and water in the system is azeotropically distilled or the like. After dehydration by the technique, an acetalization reaction can be performed by adding an alkyl vinyl ether compound and an acid catalyst, and a desired acetal group can be introduced into the phenolic hydroxyl group.

  As the monomer having a phenolic hydroxyl group, hydroxystyrenes are preferable.

  As the alkyl vinyl ether compound used in the acetalization reaction, a compound represented by the following general formula (A) is desirable.

In general formula (A),
R ¹ represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.
R _s and R _t each independently represents an alkyl group or a cycloalkyl group.

Examples of the alkyl group for R ¹ , R _s, and R _t include a linear or branched alkyl group having preferably 1 to 20 carbon atoms, more preferably 1 to 18 carbon atoms. For example, a methyl group , Ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, i-pentyl group, t-pentyl group, n-hexyl group, i -Hexyl group, t-hexyl group, n-heptyl group, i-heptyl group, t-heptyl group, n-octyl group, i-octyl group, t-octyl group, n-nonyl group, i-nonyl group, t -Nonyl group, n-decyl group, i-decyl group, t-decyl group, n-undecyl group, i-undecyl group, n-dodecyl group, i-dodecyl group, n-tridecyl group, i-tridecyl group, n -Tetradecyl group, i-tetradecyl Group, n-pentadecyl group, i-pentadecyl group, n-hexadecyl group, i-hexadecyl group, n-heptadecyl group, i-heptadecyl group, n-octadecyl group, i-octadecyl group, n-nonadecyl group, i-nonadecyl group Groups and the like.
These substituents may be substituted by the substituents shown below.

Preferred examples of the cycloalkyl group represented by R ¹ , R _s and R _t include cycloalkyl having 3 to 20 carbon atoms, more preferably 3 to 18 carbon atoms. For example, cyclopropyl group, cyclobutyl group, cyclopentyl Group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cycloundecyl group, cyclododecyl group, cyclotridecyl group, cyclotridecyl group, cyclotetradecyl group, cyclopentadecyl group, cyclohexadecyl group List decyl, cycloheptadecyl, cyclooctadecyl, cyclononadecyl, 4-cyclohexylcyclohexyl, 4-n-hexylcyclohexyl, pentanylcyclohexyl, hexyloxycyclohexyl, pentanyloxycyclohexyl, etc. Can do. Substituted cyclic alkyl groups other than those listed here can also be used within the above ranges.
These substituents may be substituted by the substituents shown below.

The aryl group for R ¹ is preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 25 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, an ethylphenyl group, and a propylphenyl group. Group, methoxyphenyl group, ethoxyphenyl group, propyloxyphenyl group, 4-cyclopentylphenyl group, 4-cyclohexylphenyl group, 4-cycloheptenylphenyl group, 4-cyclooctanylphenyl group, 2-cyclopentylphenyl group, 2 -Cyclohexylphenyl group, 2-cycloheptenylphenyl group, 2-cyclooctanylphenyl group, 3-cyclopentylphenyl group, 3-cyclohexylphenyl group, 3-cycloheptenylphenyl group, 3-cyclooctanylphenyl group, 4 A cyclopentyloxyphenyl group, -Cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group, 2-cyclo Octanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctenyloxyphenyl group, 4-n-pentylphenyl group, 4-n- Hexylphenyl group, 4-n-heptenylphenyl group, 4-n-octanylphenyl group, 2-n-pentylphenyl group, 2-n-hexylphenyl group, 2-n-heptenylphenyl group, 2-n -Octanylphenyl group, 3-n-pentylphenyl group, 3-n-hexylphenyl group, 3-n-heptenylphenyl group, 3-n-octanylphenyl group, 2,6-di-isopropylphenyl group, 2,3-di-isopropylphenyl group, 2,4- Di-isopropylphenyl group, 3,4-di-isopropylphenyl group, 3,6-di-t-butylphenyl group, 2,3-di-t-butylphenyl group, 2,4-di-t-butylphenyl Group, 3,4-di-t-butylphenyl group, 2,6-di-n-butylphenyl group, 2,3-di-n-butylphenyl group, 2,4-di-n-butylphenyl group, 3,4-di-n-butylphenyl group, 2,6-di-i-butylphenyl group, 2,3-di-i-butylphenyl group, 2,4-di-i-butylphenyl group, 3, 4-di-i-butylphenyl group, 2,6-di-t-amylphe Group, 2,3-di-t-amylphenyl group, 2,4-di-t-amylphenyl group, 3,4-di-t-amylphenyl group, 2,6-di-i-amylphenyl group 2,3-di-i-amylphenyl group, 2,4-di-i-amylphenyl group, 3,4-di-i-amylphenyl group, 2,6-di-n-pentylphenyl group, 2 , 3-Di-n-pentylphenyl group, 2,4-di-n-pentylphenyl group, 3,4-di-n-pentylphenyl group, 4-adamantylphenyl group, 2-adamantylphenyl group, 4-iso Boronylphenyl group, 3-isobornylphenyl group, 2-isobornylphenyl group, 4-cyclopentyloxyphenyl group, 4-cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooctanyloxy Enyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group, 3 -Cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentyloxyphenyl group, 4-n-hexyloxyphenyl group, 4-n-heptenyloxyphenyl group, 4-n-octa Nyloxyphenyl group, 2-n-pentyloxyphenyl group, 2-n-hexyloxyphenyl group, 2-n-heptenyloxyphenyl group, 2-n-octanyloxyphenyl group, 3-n-pentyloxyphenyl Group, 3-n-hexyloxyphenyl group, 3-n-hept Tenenyloxyphenyl group, 3-n-octanyloxyphenyl group, 2,6-di-isopropyloxyphenyl group, 2,3-di-isopropyloxyphenyl group, 2,4-di-isopropyloxyphenyl group, 3, 4-di-isopropyloxyphenyl group, 2,6-di-t-butyloxyphenyl group, 2,3-di-t-butyloxyphenyl group, 2,4-di-t-butyloxyphenyl group, 3, 4-di-t-butyloxyphenyl group, 2,6-di-n-butyloxyphenyl group, 2,3-di-n-butyloxyphenyl group, 2,4-di-n-butyloxyphenyl group, 3,4-di-n-butyloxyphenyl group, 2,6-di-i-butyloxyphenyl group, 2,3-di-i-butyloxyphenyl group, 2,4-di-i-butyloxyphenyl group Base 3,4-di-i-butyloxyphenyl group, 2,6-di-t-amyloxyphenyl group, 2,3-di-t-amyloxyphenyl group, 2,4-di-t-amyloxyphenyl group Group, 3,4-di-t-amyloxyphenyl group, 2,6-di-i-amyloxyphenyl group, 2,3-di-i-amyloxyphenyl group, 2,4-di-i-amyl Oxyphenyl group, 3,4-di-i-amyloxyphenyl group, 2,6-di-n-pentyloxyphenyl group, 2,3-di-n-pentyloxyphenyl group, 2,4-di-n -Pentyloxyphenyl group, 3,4-di-n-pentyloxyphenyl group, 4-adamantyloxyphenyl group, 3-adamantyloxyphenyl group, 2-adamantyloxyphenyl group, 4-isoboronyloxyphenyl group, - isobornyl oxyphenyl group, 2-isobornyl oxyphenyl group, etc. include those not limited to substituents other than well above examples be further substituted as long as it is within the above range.
These substituents may be substituted by the substituents shown below.

The aralkyl group for R ¹ is preferably an aralkyl group having 7 to 30 carbon atoms, more preferably 8 to 25 carbon atoms, such as a phenylethyl group, a tolylphenylethyl group, a xylylphenylethyl group, Ethylphenylethyl group, propylphenylethyl group, 4-cyclopentylphenylethyl group, 4-cyclohexylphenylethyl group, 4-cycloheptenylphenylethyl group, 4-cyclooctanylphenylethyl group, 2-cyclopentylphenylethyl group, 2 -Cyclohexylphenylethyl group, 2-cycloheptenylphenylethyl group, 2-cyclooctanylphenylethyl group, 3-cyclopentylphenylethyl group, 3-cyclohexylphenylethyl group, 3-cycloheptenylphenylethyl group, 3-cycloocta Ruphenylethyl group, 4-cyclopentyloxyphenylethyl group, 4-cyclohexyloxyphenylethyl group, 4-cycloheptenyloxyphenylethyl group, 4-cyclooctanyloxyphenylethyl group, 2-cyclopentyloxyphenylethyl group, 2 -Cyclohexyloxyphenylethyl group, 2-cycloheptenyloxyphenylethyl group, 2-cyclooctanyloxyphenylethyl group, 3-cyclopentyloxyphenylethyl group, 3-cyclohexyloxyphenylethyl group, 3-cycloheptenyloxyphenyl Ethyl group, 3-cyclooctanyloxyphenylethyl group, 4-n-pentylphenylethyl group, 4-n-hexylphenylethyl group, 4-n-heptenylphenylethyl group, 4-n-octanylphenyl Ethyl group, 2-n-pentylphenylethyl group, 2-n-hexylphenylethyl group, 2-n-heptenylphenylethyl group, 2-n-octanylphenylethyl group, 3-n-pentylphenylethyl group, 3-n-hexylphenylethyl group, 3-n-heptenylphenylethyl group, 3-n-octanylphenylethyl group, 2,6-di-isopropylphenylethyl group, 2,3-di-isopropylphenylethyl group 2,4-di-isopropylphenylethyl group, 3,4-di-isopropylphenylethyl group, 2,6-di-t-butylphenylethyl group, 2,3-di-t-butylphenylethyl group, 2 , 4-Di-t-butylphenylethyl group, 3,4-di-t-butylphenylethyl group, 2,6-di-n-butylphenylethyl group, 2,3- -N-butylphenylethyl group, 2,4-di-n-butylphenylethyl group, 3,4-di-n-butylphenylethyl group, 2,6-di-i-butylphenylethyl group, 2,3 -Di-i-butylphenylethyl group, 2,4-di-i-butylphenylethyl group, 3,4-di-i-butylphenylethyl group, 2,6-di-t-amylphenylethyl group, 2 , 3-Di-t-amylphenylethyl group, 2,4-di-t-amylphenylethyl group, 3,4-di-t-amylphenylethyl group, 2,6-di-i-amylphenylethyl group 2,3-di-i-amylphenylethyl group, 2,4-di-i-amylphenylethyl group, 3,4-di-i-amylphenylethyl group, 2,6-di-n-pentylphenyl Ethyl group, 2,3-di-n-pentylphenyl Til group, 2,4-di-n-pentylphenylethyl group, 3,4-di-n-pentylphenylethyl group, 4-adamantylphenylethyl group, 3-adamantylphenylethyl group, 2-adamantylphenylethyl group, 4-isobornylphenylethyl group, 3-isobornylphenylethyl group, 2-isobornylphenylethyl group, 4-cyclopentyloxyphenylethyl group, 4-cyclohexyloxyphenylethyl group, 4-cycloheptenyloxyphenyl Ethyl group, 4-cyclooctanyloxyphenylethyl group, 2-cyclopentyloxyphenylethyl group, 2-cyclohexyloxyphenylethyl group, 2-cycloheptenyloxyphenylethyl group, 2-cyclooctanyloxyphenylethyl group, 3 -Cyclopentyloxyph Enylethyl group, 3-cyclohexyloxyphenylethyl group, 3-cycloheptenyloxyphenylethyl group, 3-cyclooctanyloxyphenylethyl group, 4-n-pentyloxyphenylethyl group, 4-n-hexyloxyphenylethyl Group, 4-n-heptenyloxyphenylethyl group, 4-n-octanyloxyphenylethyl group, 2-n-pentyloxyphenylethyl group, 2-n-hexyloxyphenylethyl group, 2-n-heptenyl Oxyphenylethyl group, 2-n-octanyloxyphenylethyl group, 3-n-pentyloxyphenylethyl group, 3-n-hexyloxyphenylethyl group, 3-n-heptenyloxyphenylethyl group, 3-n -Octanyloxyphenylethyl group, 2,6-diisopropyloxy Phenylethyl group, 2,3-di-isopropyloxyphenylethyl group, 2,4-di-isopropyloxyphenylethyl group, 3,4-diisopropyloxyphenylethyl group, 2,6-di-t-butyloxyphenyl Ethyl group, 2,3-di-t-butyloxyphenylethyl group, 2,4-di-t-butyloxyphenylethyl group, 3,4-di-t-butyloxyphenylethyl group, 2,6-di -N-butyloxyphenylethyl group, 2,3-di-n-butyloxyphenylethyl group, 2,4-di-n-butyloxyphenylethyl group, 3,4-di-n-butyloxyphenylethyl group 2,6-di-i-butyloxyphenylethyl group, 2,3-di-i-butyloxyphenylethyl group, 2,4-di-i-butyloxyphenylethyl group 3,4-di-i-butyloxyphenylethyl group, 2,6-di-t-amyloxyphenylethyl group, 2,3-di-t-amyloxyphenylethyl group, 2,4-di-t -Amyloxyphenylethyl group, 3,4-di-t-amyloxyphenylethyl group, 2,6-di-i-amyloxyphenylethyl group, 2,3-di-i-amyloxyphenylethyl group, 2 , 4-Di-i-amyloxyphenylethyl group, 3,4-di-i-amyloxyphenylethyl group, 2,6-di-n-pentyloxyphenylethyl group, 2,3-di-n-pentyl Oxyphenylethyl group, 2,4-di-n-pentyloxyphenylethyl group, 3,4-di-n-pentyloxyphenylethyl group, 4-adamantyloxyphenylethyl group, 3-adamantylio Xiphenylethyl group, 2-adamantyloxyphenylethyl group, 4-isoboronyloxyphenylethyl group, 3-isoboronyloxyphenylethyl group, 2-isoboronyloxyphenylethyl group, or the above alkyl is a methyl group , Propyl group, butyl group and the like.
These substituents may be substituted by the substituents shown below.

  As further substituents of the above groups, hydroxyl groups, halogen atoms (fluorine, chlorine, bromine, iodine), nitro groups, cyano groups, the above alkyl groups, methoxy groups, ethoxy groups, hydroxyethoxy groups, propoxy groups Hydroxypropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, alkoxy group such as t-butoxy group, alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, benzyl group, phenethyl group, cumyl group, etc. Aralkyl groups, aralkyloxy groups, formyl groups, acetyl groups, butyryl groups, benzoyl groups, cyanyl groups, acyl groups such as valeryl groups, acyloxy groups such as butyryloxy groups, the above alkenyl groups, vinyloxy groups, propenyloxy groups, allyloxy groups Alkenyloxy such as butenyloxy group , Mention may be made of the above aryl group, an aryloxy group such as phenoxy group, aryloxycarbonyl group such as benzoyloxy group.

  These substituents may further have a substituent, as long as the carbon number of the substituted aryl group or the substituted aralkyl group is within this range.

  Specific examples of the compound represented by the general formula (A) include, for example, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, n-hexyl vinyl ether, benzyl vinyl ether, Examples include cyclohexyl ethyl vinyl ether, phenoxy ethyl vinyl ether, cyclohexyl phenoxy ethyl vinyl ether, 4-carbonyl cyclohexyl phenoxy ethyl vinyl ether, t-butyl cyclohexyl carbonyloxy ethyl vinyl ether, cyclohexyl thioethyl vinyl ether, and n-butyl cyclohexyl carbonyloxy ethyl vinyl ether. Between the phenolic hydroxyl groups in the monomer As long as it causes the acetal reaction, but it is not limited to those described above. In the above, t-butyl vinyl ether, isopropyl vinyl ether, and cyclohexyl vinyl ether are preferable, and t-butyl vinyl ether is more preferable. In addition, isopropenyl ethers such as methyl isopropenyl ether, butyl isopropenyl ether, phenyl isopropenyl ether, benzyl isopropenyl ether, cyclohexyl isopropenyl ether, cyclohexylphenoxyethyl isopropenyl ether, and the like are also preferable.

  The amount of the alkyl vinyl ether compound used in the reaction is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 60 mol, based on the phenolic hydroxyl group in the monomer having a phenolic hydroxyl group. %, And more preferably 15 mol% to 50 mol%.

The organic solvent used in the reaction is not particularly limited as long as it is an inert solvent, and examples thereof include propylene glycol methyl ether acetate (PGMEA), 2-heptanone, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, and tetrahydrofuran. be able to. Of these, PGMEA and 2-heptanone are preferable.
The reaction solvent is usually used in an amount of 100 to 1000 parts by mass with respect to 100 parts by mass of the monomer having a phenolic hydroxyl group.

  The synthesis of the acid-decomposable monomer (a) is carried out by dissolving a monomer having a phenolic hydroxyl group in the organic solvent shown above (a solvent inert to the acetalization reaction), and performing distillation under reduced pressure as necessary. Water is removed and an alkyl vinyl ether compound is added. The acetalization reaction proceeds by adding an acidic catalyst.

  As the acidic catalyst, either an inorganic acid or an organic acid can be used. The organic acid is preferable because it has no residual metal impurities, and p-toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt and the like are more preferable.

  For the purpose of stopping the acetalization reaction, neutralization with a base compound is preferably performed. If this neutralization is not performed, there is a possibility that an acid remains and impairs the storage stability of the resist. The basic compound to be used is not particularly limited as long as the acid as the added catalyst is neutralized and the salt is removed in the water washing step. Among these, organic base compounds are preferable because they have no residual metal impurities, and specific examples include triethylamine, trimethylamine, pyridine, aminopyridine, piperazine, imidazole, and the like, and triethylamine and pyridine are particularly preferable.

  After the acetalization reaction is completed and neutralized, it is preferable to remove the salt remaining in the system using ultrapure water or the like.

  Specific examples of the repeating unit represented by the general formula (A1) include the following, but the present invention is not limited thereto.

In the general formula (A2), a group decomposable by the action of an acid as Rd (hereinafter also referred to as “acid-decomposable group”) is decomposed by the action of an acid generated by exposure, and has a structure of the general formula (A2). In which a carboxylic acid derived from an ester group is generated, thereby increasing the solubility in an alkaline developer. Rd preferably has an alicyclic group.
When Rd is an acid-decomposable group having an alicyclic group, the alicyclic group may be a bridged alicyclic group.

  The acid-decomposable group as Rd is preferably a group represented by the following general formula (pI) to general formula (pVI).

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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. In addition, it is preferable that at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ is 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, and at least one of R _{17 to} R ₂₁ is An alicyclic hydrocarbon group is preferred. 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, and at least one of R _{22 to} R ₂₅ is An alicyclic hydrocarbon group is preferred. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

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

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

  In the present invention, preferred examples of the alicyclic moiety include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl. Group, cyclooctyl group, cyclodecanyl group and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

  Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. The alkyl group and the alkoxy group may have a further substituent. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.

  In the general formula (A2), Rd is preferably a group represented by the following general formula (3).

In general formula (3),
R ₄ , R ₅ , and Y each independently represent an alkyl group or an alicyclic hydrocarbon group.

The group represented by the general formula (3) is preferably a group in which one of R _{12 to} R ₁₄ in the general formula (pII) is an alicyclic hydrocarbon group.

  Specific examples of the monomer corresponding to the repeating unit represented by the general formula (A2) are shown below.

  In the acid-decomposable resin, the repeating unit having a sulfonium salt structure that generates an arylsulfonic acid upon irradiation with actinic rays or radiation generates an arylsulfonic acid upon irradiation with an active ray or radiation on the side chain. It can be formed by a monomer having a sulfonium salt structure. Examples of the polymerizable functional group include (meth) acryloyl group, styryl group, vinyl ether group, vinyl group and the like.

  The repeating unit having a sulfonium salt structure that generates an arylsulfonic acid upon irradiation with actinic rays or radiation is preferably represented by the following general formula (A3).

In general formula (A3),
Ra represents a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, a chloro atom, a hydroxymethyl group or an alkoxymethyl group.
L ₁ represents a divalent linking group.
Ar ₁ and Ar ₂ each independently represent a monovalent aromatic ring. Ar ₁ and Ar ₂ may be linked to form a ring.
Ar ₃ represents a divalent aromatic ring.
A represents an aryl sulfonate anion.

Ra is preferably a hydrogen atom, a methyl group, a hydroxymethyl group, or an alkoxymethyl group.
L ₁ is preferably a linking group having a carbonyl group, an ester group, an amide group, an aralkylene group, an arylene group, an arylene carboxyl group, an oxygen atom or a sulfonyl group. More preferably, an ester group, an amide group, a phenylene group, a phenylenemethyleneoxy group, a phenylenemethyleneoxycarbonyl group, and a phenylenecarboxy group are exemplified.
Preferable as the aromatic ring of Ar1~Ar _3, a benzene ring or a naphthalene ring. These may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a hydroxy group, a nitro group, and a cyano group.
A is preferably an aryl sulfonate anion having 6 to 14 carbon atoms. Examples of the aryl group in the aryl sulfonate anion of A include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group of the aryl sulfonate anion may have a substituent. Examples of the substituent that the aryl group of the aryl sulfonate anion may have include an alkyl group (preferably having 1 to 5 carbon atoms), a halogen atom (preferably a fluorine atom), and the like. The alkyl group may be further substituted with a halogen atom (preferably a fluorine atom) or the like.

  Specific examples of the repeating unit having a sulfonium salt structure that generates an arylsulfonic acid upon irradiation with actinic rays or radiation are shown below, but the present invention is not limited thereto.

The acid-decomposable resin preferably has a repeating unit based on hydroxystyrenes.
The repeating unit of hydroxystyrenes may have a substituent such as an alkyl group or an alkoxy group on the benzene ring.

The acid-decomposable resin may have a repeating unit having a lactone group. As the lactone group, any group can be used as long as it has a lactone structure. However, it is preferably a group containing a 5- to 7-membered ring lactone structure and represented by the following general formulas (LC1-1) to (LC1). It is more preferable to have a repeating unit having a group having a lactone structure represented by any one of -12). Further, a group having a lactone structure may be directly bonded to the main chain.

The lactone structure moiety may or may not have a substituent (Rb ₃ ). Preferred substituents (Rb ₃ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of Rb ₃ may be the same or different, and a plurality of Rb ₃ may be bonded to form a ring.

  Examples of the repeating unit having a group having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-12) include a repeating unit represented by the following general formula (AI). it can.

In general formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom.

Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb ₀ is preferably a hydrogen atom or a methyl group.

Ab is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express. Preferably a single bond, -Ab ₁ -CO ₂ - is a linking group represented by.
Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.

  V represents a group represented by any one of the general formulas (LC1-1) to (LC1-12).

The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.
Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

  The acid-decomposable resin may have a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The polar group is preferably a hydroxyl group or a cyano group. Examples of the alicyclic hydrocarbon structure substituted with a polar group include structures represented by the following general formula (VIIa) or (VIIb).

In general formula (VIIa), R ₂ c to R ₄ c each independently represents a hydrogen atom, a hydroxyl group, or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group or a cyano group. Preferably R
1 of ₂ c to R ₄ c one or two and the remainder is a hydrogen atom in a hydroxyl group, more preferably the remainder is a hydrogen atom at two of the hydroxyl group of R ₂ c to R ₄ c.

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

  Examples of the repeating unit having a group represented by the general formula (VIIa) or (VIIb) include a repeating unit represented by the following general formula (AIIa) or (AIIb).

In general formulas (AIIa) and (AIIb),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

  Specific examples of the repeating unit having a structure represented by the general formulas (AIIa) and (AIIb) are given below, but the present invention is not limited thereto.

  The acid-decomposable resin can have various repeating units in addition to the above repeating units.

Examples of such a repeating unit include, but are not limited to, repeating units corresponding to the following monomers.
Examples of such monomers include acrylic acid esters, methacrylic acid esters,
Examples thereof include compounds having one addition polymerizable unsaturated bond such as acrylamides, methacrylamides, allyl compounds, vinyl ethers and vinyl esters.

  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 the acid-decomposable resin, the content of the repeating unit represented by the general formula (A1) or (A2) is preferably 10 to 50 mol%, more preferably 15 to 40 mol%. .
In the acid-decomposable resin, the content of the repeating unit having a sulfonium salt structure that generates an aryl sulfonic acid upon irradiation with actinic rays or radiation is preferably 2 to 20 mol%, and 5 to 15 mol%. More preferably.

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

  The weight average molecular weight of the acid-decomposable resin is preferably 2,000 to 200,000 as a polystyrene conversion value by GPC method. By making the weight average molecular weight 2,000 or more, heat resistance and dry etching resistance can be improved, and by making the weight average molecular weight 200,000 or less, developability can be improved. And since a viscosity becomes low, film forming property can be improved. The molecular weight is more preferably 5,000 to 50,000, and still more preferably 7,000 to 30,000. By adjusting the molecular weight, it is possible to achieve both heat resistance, resolution, development defects, and the like of the composition. The dispersity (Mw / Mn) of the acid-decomposable resin is preferably 1.0 to 3.0, more preferably 1.2 to 2.5, and still more preferably 1.2 to 1.8. . The line edge roughness performance can be improved by adjusting the degree of dispersion to an appropriate range.

  In the positive resist composition of the present invention, the blending amount of the acid-decomposable resin in the whole composition is preferably 40 to 99.99% by mass, more preferably 50 to 99% by mass, and still more preferably in the total solid content. Is 80-96 mass%.

  Specific examples of the acid-decomposable resin are shown below, but the present invention is not limited thereto.

[2] Compound (component B) that generates sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine upon irradiation with actinic rays or radiation
The positive resist composition of the present invention contains a compound that generates sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine upon irradiation with actinic rays or radiation.
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds and mixtures thereof that generate sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine upon irradiation with radiation 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.

  In addition, a group that generates sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine by irradiation of these actinic rays or radiation, or a compound in which the compound is introduced into the main chain or side chain of the polymer, for example, the United States Patent No. 3,849,137, German Patent No. 3914407, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP The compounds described in JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, etc. can be used.

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

  Among the compounds that generate sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine upon irradiation with active light or radiation that may be used, the following general formulas (ZI), (ZII), And a compound represented by (ZIII).

In the above general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a sulfonate anion, a bis (alkylsulfonyl) amide anion, or a tris (alkylsulfonyl) methine anion.

  Preferred sulfonic acid anions, bis (alkylsulfonyl) amide anions, and tris (alkylsulfonyl) methine anions include sulfonic acid anions, bis (alkylsulfonyl) amide anions, and tris (alkylsulfonyl) methine anions represented by the following general formula.

Rc ₁ represents an organic group.
Examples of the organic group for Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, a cycloalkyl group, an aryl group, or a plurality thereof is a single bond, —O—, —CO ₂ —, —S—. , —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like.
Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group.
Examples of the organic group of Rc ₃ , Rc ₄ , and Rc ₅ are preferably the same as the preferable organic group in Rc ₁ , and more 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 , Rc ₃ , Rc ₄ and Rc ₅ is particularly preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.

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

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

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

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

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

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group having 1 to 10 carbon atoms, e.g., methyl group, ethyl group, propyl group , A butyl group, a pentyl group, and the like, and a linear, branched 2-oxoalkyl group, and an alkoxycarbonylmethyl group are more preferable.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group, and a norbornyl group, more a cyclic 2-oxoalkyl group preferable.
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and is preferably a group having> C═O at the 2-position of the above alkyl group or cycloalkyl group Can be mentioned.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, pentyloxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl 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 , R _6c and R _7c, 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 or an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c, and R _x and R _y include a butylene group and a pentylene group.
Zc ⁻ represents a sulfonic acid anion, a bis (alkylsulfonyl) amide anion or a tris (alkylsulfonyl) methine anion, and in the general formula (Z1), X ^{− is} a sulfonic acid anion, bis (alkylsulfonyl) amide anion or tris ( Alkylsulfonyl) methine anion can be exemplified.

The alkyl group as R _{1c to} R _7c may be either linear or branched, preferably a linear or branched alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms. And a straight chain or branched alkyl group, for example, a methyl group, an ethyl group, a straight chain or a branched propyl group, a straight chain or a branched butyl group, a straight chain or a branched pentyl group.
The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group and a cyclohexyl group.
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably, any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _1c to R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl groups and cycloalkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is more preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group. The cycloalkyl group as R _x and R _y is more preferably a cyclic 2-oxoalkyl group.
Examples of the linear, branched or cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .

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

In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group or a cycloalkyl group.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group having 1 to 10 carbon atoms, e.g., methyl group, ethyl group, propyl group Butyl group and pentyl group.
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 carbon atoms. For example, a cyclopentyl group, a cyclohexyl group, and a norbornyl group can be mentioned.
R ₂₀₄ to R ₂₀₇ may have a substituent. The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents a sulfonate anion, a bis (alkylsulfonyl) amide anion or a tris (alkylsulfonyl) methine anion, and the X ⁻ sulfonate anion, bis (alkylsulfonyl) amide anion or tris ( Alkylsulfonyl) methine anion can be exemplified.

  Examples of the compound that generates sulfonic acid upon irradiation with actinic rays or radiation that can be used further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

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

  Of the compounds that generate sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are more preferable. .

  Examples of particularly preferable compounds among the compounds that decompose upon irradiation with actinic rays or radiation to generate sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine are given below.

  (B) The addition amount of the compound of a component is 0.1-20 mass% normally with respect to the total solid of a composition, Preferably it is 0.5-20 mass%, More preferably, it is 1-10 mass%.

  In the present invention, if necessary, as a compound capable of generating an acid upon irradiation with actinic rays or radiation, other compounds such as a carboxylic acid upon irradiation with actinic rays or radiation are used together with the compound of component (B). You may use together the compound to generate | occur | produce.

[3] (C) Solvent The composition of the present invention is dissolved in a machine solvent that dissolves the above-described components and optional components described below, and is applied onto a support. Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

Among these, preferable organic solvents include 2-heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl. Examples include ether acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, N-methylpyrrolidone, and tetrahydrofuran.

(Other components used in the present invention)
In the positive resist composition of the present invention, an alkali-soluble resin not containing an acid-decomposable group can be blended as a resin component in addition to the acid-decomposable resin, thereby improving sensitivity.

  The alkali-soluble resin containing no acid-decomposable group (hereinafter simply referred to as “alkali-soluble resin”) is a resin that is soluble in alkali, and preferred examples include polyhydroxystyrene, novolak resin, and derivatives thereof. A copolymer resin containing a p-hydroxystyrene unit can also be used if it is alkali-soluble.

  Among them, poly (p-hydroxystyrene), poly (p- / m-hydroxystyrene) copolymer, poly (p- / o-hydroxystyrene) copolymer, poly (p-hydroxystyrene / styrene) copolymer Coalescence is preferably used. Furthermore, poly (alkyl-substituted hydroxystyrene) resins such as poly (4-hydroxy-3-methylstyrene) and poly (4-hydroxy-3,5-dimethylstyrene), and some of the phenolic hydroxyl groups of the above resins are alkylated. An acetylated resin is also preferably used if it is alkali-soluble.

  Furthermore, when a part of the phenol nuclei of the resin (30 mol% or less of the total phenol nuclei) is hydrogenated, the transparency of the resin is improved, which is preferable in terms of sensitivity, resolving power, and profile rectangle formation.

  In the present invention, the addition amount in the composition of the alkali-soluble resin not containing the acid-decomposable group is preferably 2 to 60% by mass, more preferably, based on the total mass of the solid content of the composition. It is 5-30 mass%.

  The positive resist composition of the present invention further promotes solubility in acid-decomposable dissolution-accelerating compounds, dyes, plasticizers, surfactants, photosensitizers, basic compounds, and developers as necessary. A compound etc. can be contained.

  In the positive resist composition of the present invention, (D) fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant and surfactant containing both fluorine atoms and silicon atoms) Can be contained.

  Examples of these surfactants include, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540. No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, U.S. Pat. , 5824451, and the following commercially available surfactants can be used as they are.

  Commercially available surfactants that can be used include, for example, F-top EF301, EF303 (made by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (made by Sumitomo 3M Ltd.), MegaFuck F171, F173, F176, F189, R08 Fluorine-based materials (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.) There may be mentioned surfactants or silicon surfactants. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon surfactant.

The compounding amount of these surfactants is usually 0.01% by mass to 2% by mass, preferably 0.01% by mass to 1% by mass, per 100% by mass of the solid content in the composition of the present invention.
These surfactants can be used alone or in combination of two or more.

  In the positive resist composition of the present invention, (E) a basic compound, more preferably an organic basic compound can be used. Thereby, the stability improvement at the time of a preservation | save can be aimed at.

A preferable organic basic compound that can be used in the present invention is a compound that is more basic than phenol. Of these, nitrogen-containing basic compounds are preferred.
Preferable chemical environments include the structures of the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, wherein R ²⁵¹ and R ²⁵² are bonded to each other. To form a ring. The alkyl group and aryl group may have a substituent such as a hydroxy group or an amino group.

In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ are the same or different and represent an alkyl group having 1 to 20 carbon atoms.

  Further preferred compounds are nitrogen-containing cyclic compounds or nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule.

  The nitrogen-containing cyclic compound is more preferably a polycyclic structure. Preferable specific examples of the nitrogen-containing polycyclic compound include compounds represented by the following general formula (F).

  In formula (F), Y and Z each independently represent a linear, branched or cyclic alkylene group which may contain a hetero atom and may be substituted.

Here, examples of the hetero atom include a nitrogen atom, a sulfur atom, and an oxygen atom.
The alkylene group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms. Examples of the substituent of the alkylene group include a halogen atom and a halogen-substituted alkyl group in addition to an alkyl group having 1 to 6 carbon atoms, an aryl group, and an alkenyl group. Furthermore, specific examples of the compound represented by formula (F) include the compounds shown below.

  Among these, 1,8-diazabicyclo [5.4.0] undec-7-ene and 1,5-diazabicyclo [4.3.0] non-5-ene are particularly preferable.

  The nitrogen-containing basic compound having two or more nitrogen atoms of different chemical environments in one molecule is particularly preferably a compound or alkylamino containing both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. A compound having a group. Particularly preferred compounds include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4- Dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6- Methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2, 6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methylpyrazine, Pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, trimethylimidazole, triphenylimidazole, methyldiphenyl Although imidazole etc. are mentioned, it is not limited to this.

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass parts normally with respect to 100 mass parts of compositions (solid content), Preferably it is 0.01-5 mass parts.

The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular compound having a molecular weight of 1,000 or less and having two or more phenolic hydroxyl groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or an aliphatic compound is preferable for the same reason as described above.

  A preferable addition amount of these dissolution accelerating compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the polymer in the present invention from the viewpoint of development residue and pattern deformation during development.

  Such a phenol compound having a molecular weight of 1,000 or less can be obtained by, for example, the method described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. It can be easily synthesized by those skilled in the art with reference.

  Although the specific example of a phenol compound is shown below, the compound which can be used by this invention is not limited to these.

  Resorcin, phloroglucin, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,3 ', 4', 5'-hexahydroxybenzophenone, acetone-pyrogallol condensation Resin, fluoroglucoside, 2,4,2 ', 4'-biphenyltetrol, 4,4'-thiobis (1,3-dihydroxy) benzene, 2,2', 4,4'-tetrahydroxydiphenyl ether, 2, 2 ', 4,4'-tetrahydroxydiphenyl sulfoxide, 2,2', 4,4'-tetrahydroxydiphenyl sulfone, tris (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) Cyclohexane, 4,4- (α-methylbenzylidene) bisphenol, α, α ′, α ″ -tris 4-hydroxyphenyl) -1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene, 1,2,2-tris (hydroxy Phenyl) propane, 1,1,2-tris (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2,5,5-tetrakis (4-hydroxyphenyl) hexane, 1,2-tetrakis (4- Hydroxyphenyl) ethane, 1,1,3-tris (hydroxyphenyl) butane, para [α, α, α ′, α′-tetrakis (4-hydroxyphenyl)]-xylene and the like.

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

In order to improve the acid generation rate by exposure, the following photosensitizers can be added. Specific examples of suitable photosensitizers include benzophenone, p, p′-tetramethyldiaminobenzophenone, p, p′-tetraethylethylaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, anthracene, and pyrene. Perylene, phenothiazine, benzyl, acridine orange, benzoflavin, cetoflavin-T, 9,10-diphenylanthracene, 9-fluorenone, acetophenone, phenanthrene, 2-nitrofluorene, 5-nitroacenaphthene, benzoquinone, 2-chloro-4 -Nitroaniline, N-acetyl-p-nitroaniline, p-nitroaniline, N-acetyl-4-nitro-1-naphthylamine, picramid, anthraquinone, 2-ethylanthraquinone, 2-tert-butyla Torakinon 1,2-anthraquinone, 3-methyl-1,3-diaza-1,9-benzanthrone, dibenzalacetone, 1
, 2-naphthoquinone, 3,3′-carbonyl-bis (5,7-dimethoxycarbonylcoumarin), coronene, and the like, but are not limited thereto.

  Moreover, these photosensitizers can also be used as a light absorber for far ultraviolet light as a light source. In this case, the light-absorbing agent reduces the reflected light from the substrate and reduces the influence of multiple reflection in the resist film, thereby exhibiting the effect of improving the standing wave.

  In the present invention, a surfactant other than the fluorine-based and / or silicon-based surfactant may be added. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Te - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

  The blending amount of these surfactants is usually 2% by mass or less, preferably 1% by mass or less, per 100% by mass of the solid content in the composition of the present invention.

  These surfactants may be added alone or in some combination.

A positive resist composition according to the present invention is applied onto a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device by an appropriate application method such as a spinner or a coater, and then pre-baked. A good resist pattern can be obtained by exposing through a predetermined mask, post-baking and developing. The exposure light here is preferably far ultraviolet rays having a wavelength of 250 nm or less. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), EUV (13 nm), X-ray, electron beam, and the like.

  Examples of the developer for the positive resist composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, ethylamine, n-propylamine and the like. Primary amines, 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 Alkaline aqueous solutions such as quaternary ammonium salts such as hydroxide and cyclic amines such as pyrrole and pihelidine can be used.

  Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.

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

Synthesis Example 1 (Synthesis of acid-decomposable resin (A-1))
A THF solution (27% by mass) of 2-ethoxyethoxystyrene, t-butyl methacrylate, 4- (methacryloyloxy) phenyldiphenylsulfonium 2,4,6-trimethylbenzenesulfonate manufactured by Tosoh Corporation and having a molar ratio of 37/55/8. ) 240 g was prepared, and this solution was heated to 75 ° C. under nitrogen, and Wako Pure Chemical Industries, Ltd. V-601 (1 mol% based on the total number of monomers) was added as an azo initiator. The reaction was allowed to proceed with stirring for 6 hours. After returning the obtained polymer solution to room temperature, distilled water and 0.1N hydrochloric acid were added and stirred for 30 minutes. The reaction solution was neutralized by adding triethylamine and then reprecipitated in 2 L of distilled water to take out the polymer as a powder. The operation of dissolving the polymer in 100 ml of acetone and then adding distilled water to precipitate the polymer was repeated three times. The finally precipitated polymer was powdered by drying under reduced pressure to obtain an acid-decomposable resin (A-1). With respect to this acid-decomposable resin (A-1), the weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 10200, and the dispersity (Mw / Mn) was 1.50.

Acid-decomposable resins (A-2) to (A-25) were synthesized by the same method as in Synthesis Example 1.
Table 1 below shows the composition ratio, weight average molecular weight, and dispersity of the acid-decomposable resins (A-1) to (A-25).

  Hereinafter, the structures of the acid-decomposable resins (C-1) and (C-2) used in the comparative examples are shown.

  Each solution of the acid-decomposable resins (A-1) to (A-25) and the acid-decomposable resins (C-1) to (C-2) of the comparative examples was obtained by using a solid content concentration of 20% by mass in PGMEA. It adjusted so that it might become and was used for the following Example and comparative example.

<Evaluation by electron beam irradiation>
Examples 1 to 20 and Comparative Example 1
(Preparation of positive resist composition)
Each component shown in Table 2 below was dissolved in 8.4 g of PGMEA and filtered through a 0.1 μm filter to prepare a positive resist composition.

  This positive resist composition is uniformly applied on a silicon wafer subjected to hexamethyldisilazane treatment using a spin coater, and is heated and dried on a hot plate at 120 ° C. for 90 seconds to obtain a 0.3 μm resist. A film was formed.

(Production and evaluation of body type resist pattern)
The resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750, acceleration voltage 50 KeV, manufactured by Hitachi, Ltd.). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried.
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). The resolving power was defined as the limiting resolving power (line and space were separated and resolved) at an irradiation dose for resolving a 0.15 μm line (line: space = 1: 1).
A wafer is set in a vacuum chamber, irradiated with an electron beam with the above-mentioned sensitivity, and immediately after irradiation or after 3 hours, baked at 110 ° C. for 90 seconds (heat treatment) as described above, followed by development and line pattern Got. Then, a 0.15 μm line pattern obtained by baking and developing immediately after electron beam irradiation and a 0.15 μm line pattern obtained by baking and developing after 3 hours of electron beam irradiation were scanned using a scanning electron beam. Measurement of line width variation and line edge roughness (LER) change with a micro-mirror (S-9220 manufactured by Hitachi, Ltd.) (The line width for the range of 5 μm edge in the longitudinal direction of 0.15 μm line pattern) 50 points were measured, the standard deviation was obtained, and 3σ was calculated).
The number of defects present on the wafer was counted using a defect inspection apparatus manufactured by KLA.
The entire surface of the resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). The exposure amount was the same as the exposure amount required for resolving the 0.15 μm line (line: space = 1: 1) in the pattern formation evaluation. After the electron beam irradiation, the film thickness was measured as it was without baking, and the quotient (remaining film ratio) of the film thickness before and after the electron beam irradiation was used as an outgas indicator.
The results are shown in Table 2.

  Abbreviations in Table 2 are as follows.

  “F-1” used as the surfactant represents MegaFac R08 (manufactured by Dainippon Ink & Chemicals, Inc.), and “F-2” represents Troisol S-366 (manufactured by Troy Chemical Co., Ltd.).

  “DBN” used as the basic compound represents 1,5-diazabicyclo [4.3.0] non-5-ene, and “DMAP” represents 4-N, N-dimethylaminopyridine.

  From the results shown in Table 2, the positive resist composition of the present invention is excellent in resolving power, line edge roughness, development defect, and outgas in characteristics evaluation by electron beam irradiation, and line width variation and LWR variation in PED in vacuum. It can be seen that there are few.

<Evaluation by EUV exposure>
Examples 21 and 22 and Comparative Example 2
Using the resist compositions of Examples 1 and 2 and Comparative Example 1, resist films were obtained in the same manner as in Example 1. However, the resist film thickness was 0.25 μm. The obtained resist film was subjected to surface exposure using EUV light (wavelength 13 nm) while changing the exposure amount by 0.5 mJ in the range of 0 to 5.0 mJ, and further baked at 110 ° C. for 90 seconds. Then, using a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure amount was measured to obtain a sensitivity curve. In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. Although the γ value is large, the dissolution contrast is excellent.
The results are shown in Table 3.

  From Table 3, it can be seen that the positive resist composition of the present invention is superior in sensitivity and high contrast as compared with the composition of the comparative example in the property evaluation by irradiation with EUV light.

<Evaluation by ArF exposure>
Examples 23 to 32 and Comparative Example 3
Each component shown in Table 4 below was dissolved in 8.4 g of the solvent shown in Table 4 and filtered through a 0.1 μm filter to prepare a positive resist composition. As the acid-decomposable resin, 7.66 g of PGMEA solution was used.
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.
A resist composition (solid content concentration 5%) prepared thereon was applied, and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. The obtained wafer was exposed using an ArF excimer laser immersion scanner. Thereafter, heating was performed at 120 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 60 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). The resolving power was defined as the limiting resolving power (line and space were separated and resolved) at a dose for resolving a 0.09 μm line (line: space = 1: 1).
With respect to the obtained 0.09 μm line pattern, the change in line width roughness (LWR) was measured with a scanning electron microscope (S-9220 manufactured by Hitachi, Ltd.) (the longitudinal direction of the 0.09 μm line pattern) In the 5 μm edge range, the distance from the reference line where the edge should be was measured at 50 points, the standard deviation was obtained, and 3σ was calculated.
The number of defects present on the wafer was counted using a defect inspection apparatus manufactured by KLA. The evaluation results are shown in Table 4.

  Abbreviations in Table 4 are as follows.

N-1: Dipropylaniline N-2: Triethanolamine N-3: Trioctylamine N-4: Tris-2- (2-methoxy (ethoxy)) ethylamine N-5: 2,6-diisopropylaniline N- 6: Triphenylimidazole

SL-2: Cyclohexanone SL-4; Propylene glycol monomethyl ether acetate SL-5: Ethyl lactate SL-6: Propylene glycol monomethyl ether In each table, the ratio when a plurality of resins or solvents are used is a mass ratio. .

  From Table 4, it is clear that the positive resist composition of the present invention is excellent in resolution, development defect and LWR evaluation by ArF exposure.

Claims (9)

(A) At least one type of repeating unit selected from the repeating unit represented by the following general formula (A1) and the repeating unit represented by the general formula (A2), and an arylsulfonic acid is generated by irradiation with actinic rays or radiation and a repeating unit having a sulfonium salt structure, the resin increases the solubility in an alkaline developer under the action of an acid and,
(B) a compound different from the resin (A) that generates sulfonic acid, bis (alkylsulfonyl) amide or tris (alkylsulfonyl) methine by irradiation with actinic rays or radiation ,
A positive resist composition comprising:

In general formula (A1),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, an alkoxy group or an acyloxy group.
A ₁ represents a group that is decomposed by the action of an acid.
n represents 0-4.
In general formula (A2),
Ra represents a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, a chloro atom, a hydroxymethyl group or an alkoxymethyl group.
L represents a single bond or a divalent linking group.
Rd represents a group that decomposes by the action of an acid. The repeating unit having a sulfonium salt structure that generates an arylsulfonic acid upon irradiation with actinic rays or radiation in the resin of component (A) is represented by the following general formula (A3). A positive resist composition.

In general formula (A3),
Ra represents a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, a chloro atom, a hydroxymethyl group or an alkoxymethyl group.
L ₁ represents a divalent linking group.
Ar ₁ and Ar ₂ each independently represent a monovalent aromatic ring. Ar ₁ and Ar ₂ may be linked to form a ring.
Ar ₃ represents a divalent aromatic ring.
A represents an aryl sulfonate anion The resin (A) has a repeating unit represented by the general formula (A1), and in the repeating unit represented by the general formula (A1), A ₁ is a group having a cyclic carbon structure. The positive resist composition according to claim 1 or 2.   The resin (A) has a repeating unit represented by the general formula (A2), and in the repeating unit represented by the general formula (A2), Rd is a group represented by the following general formula (pII) The positive resist composition according to claim 1, wherein the positive resist composition is present.

  In general formula (pII):
  R ₁₂ ~ R ₁₄ Each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, and R ₁₂ ~ R ₁₄ At least one of them is an alicyclic hydrocarbon group.   Resin (A) has a repeating unit represented by the following general formula (AI), The positive resist composition in any one of Claims 1-4 characterized by the above-mentioned.

  In general formula (AI),
  Rb ₀ Represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
  Ab is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express.
  V represents a group represented by any one of the general formulas (LC1-1) to (LC1-12).

  Rb _Three Represents a substituent.
  n ₂ Represents an integer of 0 to 4. n ₂ When R is 2 or more, there are multiple Rb _Three May be the same or different, and a plurality of Rb _Three They may combine to form a ring.   The positive resist composition according to any one of claims 1 to 5, wherein the resin (A) is a resin having a repeating unit derived from a monomer represented by at least one of the following 1 to 16.

  The positive resist composition according to claim 1, wherein the compound (B) is a compound represented by the following general formulas (ZI) to (ZVI).

  In the above general formula (ZI),
  R ₂₀₁ , R ₂₀₂ And R ₂₀₃ Each independently represents an organic group having 1 to 30 carbon atoms.
  R ₂₀₄ ~ R ₂₀₇ Each independently represents an aryl group, an alkyl group or a cycloalkyl group.
  X ^- Represents one of a sulfonate anion, a bis (alkylsulfonyl) amide anion, and a tris (alkylsulfonyl) methine anion represented by the following general formula.

  Rc ₁ Represents an organic group having 1 to 30 carbon atoms.
  Rc _Three , Rc _Four And Rc _Five Each independently represents an organic group having 1 to 30 carbon atoms. Rc _Three And Rc _Four May combine to form a ring.

  In general formulas (ZIV) to (ZVI),
  Ar _Three And Ar _Four Each independently represents an aryl group.
  R ₂₀₆ , R ₂₀₇ And R ₂₀₈ Each independently represents an alkyl group or an aryl group.
  A represents an alkylene group, an alkenylene group or an arylene group. After forming a resist film by the positive resist composition according to any one of claims 1 to 7 a pattern formation method the resist film to immersion exposure, characterized by development. After forming a resist film by the positive resist composition according to any one of claims 1 to 7 exposing the resist film with the EUV light or electron beam, a pattern forming method characterized by developing.