JP5155764B2 - Positive photosensitive composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication processes, and a pattern forming method using the same. is there. More specifically, the present invention relates to a positive photosensitive composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less, preferably 220 nm or less, and an irradiation source using an electron beam, and a pattern forming method using the same.

  The chemically amplified photosensitive composition generates an acid in the exposed area by irradiation with actinic rays or radiation such as far ultraviolet light, and a reaction using this acid as a catalyst to react the irradiated and non-irradiated areas of the active ray or radiation. It is a pattern forming material that changes the solubility in a developer and forms a pattern on a substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed. Various improvements have been made in resists for ArF excimer lasers. For example, in Patent Document 1, Patent Document 2, Patent Document 3, and the like, in the alicyclic acid-decomposable repeating unit, the main chain and the acid-decomposable group are changed. Various properties have been improved by introducing a repeating unit having a spacer portion between them.
However, when forming a fine pattern with a line width of 100 nm or less, even if the resolution performance is excellent, the formed line pattern collapses, resulting in a pattern collapse problem that becomes a defect during device manufacturing. In addition, the above composition still has insufficient performance stability (exposure latitude) against exposure dose changes.

  In recent years, immersion lithography using a technique for increasing resolution in an optical microscope is known as a method for achieving finer pattern formation. In immersion lithography, exposure is performed by filling a liquid having a high refractive index (hereinafter also referred to as “immersion liquid”) between a projection lens and a sample.

  Recent progress in immersion exposure technology is reported in Non-Patent Document 1, Non-Patent Document 2, Patent Document 4, and the like. In the case of using an ArF excimer laser as a light source, pure water (refractive index of 1.44 at 193 nm) is most promising as an immersion liquid from the viewpoint of handling safety, transmittance and refractive index at 193 nm.

On the other hand, the thermal flow process is a method in which after a resist pattern is formed by a normal lithography technique, the resist pattern is subjected to heat treatment to reduce the pattern size. The resist pattern is softened by heating after pattern formation, and the size of the part where the pattern is not formed (hole diameter of the hole pattern, space width of the line and space pattern, etc.) can be reduced by flowing in the gap direction of the pattern. Is possible. However, in resist compositions used for conventional ArF excimer laser lithography, etc., the glass transition temperature of the base resin is high, so the softening of the base resin at the heating temperature in the thermal flow process is inadequate. There is a problem that it is difficult to miniaturize the resist pattern. Patent Documents 5 and 6 attempt to control the pattern size by introducing a low Tg acid-decomposable group into a resin. However, such a simple low Tg makes it difficult to achieve both resolution and resolution.

  In recent years, from the viewpoint of improving resolution, Patent Document 7 and Patent Document 8 attempt to use a resin having an acid-decomposable group at a position remote from the polymer main chain via various spacer groups. However, the introduction of the spacer group alone was not enough to reduce the Tg.

JP 2005-331918 A Japanese Patent Laid-Open No. 2004-184637 JP 2003-330192 A SPIE Proc 4688,11 (2002) J.Vac.Sci.Tecnol.B 17 (1999) JP-A-10-303114 JP 2007-114412 A JP 2007-146613 A JP-T-2006-501495 JP 2005-331918 A

  The present invention has been made in view of the above circumstances, and even in the formation of a fine pattern of 100 nm or less, pattern collapse, exposure latitude, and line edge roughness are improved, and resist pattern controllability in a thermal flow process. An object is to provide an excellent positive photosensitive composition and a pattern forming method using the same.

一般式（Ｉ）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙ ₁ 、Ｒｙ ₂ 及びＲｘは、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｚａは、アルキレン基を表す。

式中、Ｌは、炭素数４〜３０の直鎖状又は分岐状のアルキレン基を表し、Ｒ ₃ は、水素原子、水酸基又は有機基を表し、Ｘは水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
〔２〕
前記一般式（ＩＩ）のＲ _３ が、カルボキシル基又はシクロアルキル基であることを特徴とする〔１〕に記載のポジ型感光性組成物。
〔３〕
（Ａ）活性光線又は放射線の照射により酸を発生する化合物及び
（Ｂ）下記一般式（Ｉ’）で表される繰り返し単位（１）と、−Ｌ−Ｒ ₃ 基（式中、Ｌは、炭素数４〜３０の２価の連結基を表し、Ｒ ₃ は、水素原子、水酸基又は有機基を表す）を有する繰り返し単位（２）とを有し、酸の作用によりアルカリ現像液に対する溶解速度が増大する樹脂
を含有することを特徴とするポジ型感光性組成物。

一般式（Ｉ’）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙ ₁ 及びＲｙ ₂ は、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｒｘ’は、炭素数２以上のアルキル基、またはシクロアルキル基を表す。ただし、Ｒｘ’としてのアルキル基は無置換アルキルである。
Ｚａ’は、炭素数１〜４の無置換アルキレン基を表す。
〔４〕
（Ａ）活性光線又は放射線の照射により酸を発生する化合物及び
（Ｂ）下記一般式（Ｉ）で表される繰り返し単位（１）と、−Ｌ−Ｒ ₃ 基（式中、Ｌは、炭素数４〜３０の２価の連結基を表し、Ｒ ₃ は、水素原子、水酸基又は有機基を表す）を有する繰り返し単位（２）とを有し、酸の作用によりアルカリ現像液に対する溶解速度が増大する樹脂
を含有することを特徴とするポジ型感光性組成物であって、
（Ｂ）成分の樹脂とは異なる下記一般式（Ａ）で表される繰り返し単位を有する樹脂を更に含有するポジ型感光性組成物。

一般式（Ｉ）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙ ₁ 、Ｒｙ ₂ 及びＲｘは、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｚａは、アルキレン基を表す。
〔５〕
（Ａ）活性光線又は放射線の照射により酸を発生する化合物及び
（Ｂ）下記一般式（Ｉ）で表される繰り返し単位（１）と、−Ｌ−Ｒ ₃ 基（式中、Ｌは、炭素数４〜３０の２価の連結基を表し、Ｒ ₃ は、水素原子、水酸基又は有機基を表す）を有する繰り返し単位（２）とを有し、酸の作用によりアルカリ現像液に対する溶解速度が増大する樹脂
を含有することを特徴とするポジ型感光性組成物であって、
（Ｂ）成分の樹脂が、一般式（Ｉ）で表される繰り返し単位（１）を２種類以上有することを特徴とするポジ型感光性組成物。

一般式（Ｉ）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙ ₁ 、Ｒｙ ₂ 及びＲｘは、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｚａは、アルキレン基を表す。
〔６〕
（Ａ）活性光線又は放射線の照射により酸を発生する化合物及び
（Ｂ）下記一般式（Ｉ）で表される繰り返し単位（１）と、−Ｌ−Ｒ ₃ 基（式中、Ｌは、炭素数４〜３０の２価の連結基を表し、Ｒ ₃ は、水素原子、水酸基又は有機基を表す）を有する繰り返し単位（２）とを有し、酸の作用によりアルカリ現像液に対する溶解速度が増大する樹脂
を含有することを特徴とするポジ型感光性組成物であって、
（Ｂ）成分の樹脂が、更に下記一般式（ＩＩＩ−２）で表される酸分解性繰り返し単位を有することを特徴とするポジ型感光性組成物。

一般式（Ｉ）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙ ₁ 、Ｒｙ ₂ 及びＲｘは、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｚａは、アルキレン基を表す。

一般式（ＩＩＩ−２）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙａは、アルキル基又はシクロアルキル基を表す。
Ｚ ₁ は、炭素原子とともにシクロアルキル基を形成するのに必要な原子団を表す。
Ｚｂは、２価の連結基を表す。
〔７〕
（Ａ）活性光線又は放射線の照射により酸を発生する化合物及び
（Ｂ）下記一般式（Ｉ）で表される繰り返し単位（１）と、−Ｌ−Ｒ ₃ 基（式中、Ｌは、炭素数４〜３０の２価の連結基を表し、Ｒ ₃ は、水素原子、水酸基又は有機基を表す）を有する繰り返し単位（２）と、
繰り返し単位（１）と異なる酸分解性繰り返し単位（３）と、下記一般式（ＩＶ）で表される繰り返し単位（４）と、下記一般式（Ｖ）で表される繰り返し単位（５）とを有し、酸の作用によりアルカリ現像液に対する溶解速度が増大する樹脂を
含有することを特徴とするポジ型感光性組成物であって、
（Ｂ）成分の樹脂は、繰り返し単位（１）〜（５）をそれぞれ少なくとも１種類以上有することを特徴とするポジ型感光性組成物。

一般式（Ｉ）に於いて、
Ｘａ ₁ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｙ ₁ 、Ｒｙ ₂ 及びＲｘは、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｚａは、アルキレン基を表す。

一般式（ＩＶ）に於いて、
Ｒ ₆ は、水素原子、ハロゲン原子又はアルキル基を表す。
Ｒ ₇ は、ラクトン構造を有する基を表す。
Ａｂは、単結合、アルキレン基、単環若しくは多環の脂環炭化水素構造を有する２価の連結基、エーテル基、エステル基、カルボニル基又はこれらを組み合わせた２価の基を表す。

一般式（Ｖ）に於いて、
Ｒ ₈ は、水素原子、メチル基、トリフロロメチル基又はヒドロキメチル基を表す。
Ｒ ₉ は、水酸基若しくはシアノ基で置換された脂環炭化水素構造を有する基を表す。
〔８〕
（Ｂ）成分の樹脂が、更に、繰り返し単位（１）と異なる酸分解性繰り返し単位（３）を有することを特徴とする〔１〕〜〔５〕のいずれかに記載のポジ型感光性組成物。
〔９〕
酸分解性繰り返し単位（３）が、下記一般式（ｐＩ）〜（ｐＶ）で表される酸の作用により脱離する基を有することを特徴とする〔７〕又は〔８〕に記載のポジ型感光性組成物。

一般式（ｐＩ）〜（ｐＶ）に於いて、
Ｒ ₁₁ は、アルキル基を表す。
Ｚは、炭素原子とともにシクロアルキル基を形成するのに必要な原子団を表す。
Ｒ ₁₂ 〜Ｒ ₁₄ は、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｒ ₁₅ 及びＲ ₁₆ は、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｒ ₁₇ 〜Ｒ ₂₁ は、各々独立に、水素原子、アルキル基又はシクロアルキル基を表す。また、Ｒ ₁₉ 、Ｒ ₂₁ のいずれかは、アルキル基又はシクロアルキル基を表す。
Ｒ ₂₂ 〜Ｒ ₂₅ は、各々独立に、水素原子、アルキル基又はシクロアルキル基を表す。また、Ｒ ₂₃ とＲ ₂₄ は、互いに結合して環を形成していてもよい。
〔１０〕
酸分解性繰り返し単位（３）が、下記一般式（ＩＩＩ−１）で表されることを特徴とする〔９〕に記載のポジ型感光性組成物。

一般式（ＩＩＩ−１）に於いて、
Ｒは、水素原子、ハロゲン原子又はアルキル基を表す。複数のＲは、各々同じでも異なっていてもよい。
Ａは、単結合、アルキレン基、エーテル基、チオエーテル基、アミド基、スルホンアミド基、ウレタン基又はウレア基よりなる群から選択される単独或いは２つ以上の基の組み合わせを表す。
Ｒｐ ₁ は、一般式（ｐＩ）〜（ｐＶ）のいずれかの基を表す。
〔１１〕
（Ｂ）成分の樹脂が、更に、下記一般式（ＩＶ）で表される繰り返し単位（４）を有することを特徴とする〔１〕〜〔６〕及び〔８〕〜〔１０〕のいずれかに記載のポジ型感光性組成物。

一般式（ＩＶ）に於いて、
Ｒ ₆ は、水素原子、ハロゲン原子又はアルキル基を表す。
Ｒ ₇ は、ラクトン構造を有する基を表す。
Ａｂは、単結合、アルキレン基、単環若しくは多環の脂環炭化水素構造を有する２価の連結基、エーテル基、エステル基、カルボニル基又はこれらを組み合わせた２価の基を表す。
〔１２〕
（Ｂ）成分の樹脂が、更に、下記一般式（Ｖ）で表される繰り返し単位（５）を有することを特徴とする〔１〕〜〔６〕及び〔８〕〜〔１１〕のいずれかに記載のポジ型感光性組成物。

一般式（Ｖ）に於いて、
Ｒ ₈ は、水素原子、メチル基、トリフロロメチル基又はヒドロキメチル基を表す。
Ｒ ₉ は、水酸基若しくはシアノ基で置換された脂環炭化水素構造を有する基を表す。
〔１３〕
前記繰り返し単位（１）の含有量が、（Ｂ）成分の樹脂における全繰り返し単位に対して５〜４０ｍｏｌ％であることを特徴とする〔１〕〜〔１２〕のいずれかに記載のポジ型感光性組成物。
〔１４〕
前記繰り返し単位（２）の含有量が、（Ｂ）成分の樹脂における全繰り返し単位に対して１〜４０ｍｏｌ％であることを特徴とする〔１〕〜〔１３〕のいずれかに記載のポジ型感光性組成物。
〔１５〕
更に、以下の（Ｓ１）〜（Ｓ５）のいずれかの混合溶剤を含有することを特徴とする〔１〕〜〔１４〕のいずれかに記載のポジ型感光性組成物。
（Ｓ１）水酸基を有する溶剤と、水酸基を有さない溶剤とを混合した混合溶剤、
（Ｓ２）エステル構造を有する溶剤と、ケトン構造を有する溶剤とを混合した混合溶剤、
（Ｓ３）エステル構造を有する溶剤と、ラクトン構造を有する溶剤とを混合した混合溶剤、
（Ｓ４）エステル構造を有する溶剤と、ラクトン構造を有する溶剤と、水酸基を有する溶剤とを混合した混合溶剤、
（Ｓ５）エステル構造を有する溶剤と、カーボネート構造を有する溶剤と、水酸基を有する溶剤を混合した混合溶剤。
〔１６〕
（Ｂ）成分の樹脂の組成物全体中の配合量が、全固形分中６０〜９９．０質量％であることを特徴とする〔１〕〜〔１５〕のいずれかに記載のポジ型感光性組成物。
〔１７〕
（Ｂ）成分の樹脂が、芳香族基を有さないことを特徴とする〔１〕〜〔１６〕のいずれかに記載のポジ型感光性組成物。
〔１８〕
〔１〕〜〔１７〕に記載のポジ型感光性組成物により形成されるレジスト膜。
〔１９〕
〔１８〕に記載のレジスト膜を形成し、該膜を露光、現像する工程を含むことを特徴とするパターン形成方法。
〔２０〕
前記露光が、液浸露光であることを特徴とする〔１９〕に記載のパターン形成方法。
なお、本発明は上記〔１〕〜〔２０〕に記載の構成を有するものであるが、以下その他についても参考のため記載した。 The present invention is as follows.
[1]
(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) a repeating unit (1) represented by the following general formula (I) and a repeating unit (2) represented by the following general formula (II) different from the repeating unit (1), and an acid Resin whose dissolution rate in an alkaline developer is increased by the action of
A positive photosensitive composition comprising:

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

In the formula, L represents a linear or branched alkylene group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group or an organic group, and X represents a hydrogen atom, an alkyl group, a cyano group or a halogen. Represents an atom.
[2]
The positive photosensitive composition as described in [1], wherein R _{3 in the} general formula (II) is a carboxyl group or a cycloalkyl group.
[3]
(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) Repeating unit (1) represented by the following general formula (I ′) and —LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ Is a resin having a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group, and whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:

In general formula (I ′),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ and Ry ₂ each independently represents an alkyl group or a cycloalkyl group.
Rx ′ represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group. However, the alkyl group as Rx ′ is unsubstituted alkyl.
Za ′ represents an unsubstituted alkylene group having 1 to 4 carbon atoms.
[4]
(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) Repeating unit (1) represented by the following general formula (I) and -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ is And a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group), and a resin whose dissolution rate in an alkali developer is increased by the action of an acid
A positive photosensitive composition comprising:
A positive photosensitive composition further containing a resin having a repeating unit represented by the following general formula (A) different from the resin of component (B).

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.
[5]
(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) Repeating unit (1) represented by the following general formula (I) and -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ is And a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group), and a resin whose dissolution rate in an alkali developer is increased by the action of an acid
A positive photosensitive composition comprising:
The positive photosensitive composition, wherein the resin of component (B) has two or more types of repeating units (1) represented by general formula (I).

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.
[6]
(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) Repeating unit (1) represented by the following general formula (I) and -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ is And a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group), and a resin whose dissolution rate in an alkali developer is increased by the action of an acid
A positive photosensitive composition comprising:
The positive photosensitive composition characterized in that the resin of component (B) further has an acid-decomposable repeating unit represented by the following general formula (III-2).

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

In general formula (III-2),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Rya represents an alkyl group or a cycloalkyl group.
Z ₁ represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
Zb represents a divalent linking group.
[7]
(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) Repeating unit (1) represented by the following general formula (I) and -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ is A repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group),
An acid-decomposable repeating unit (3) different from the repeating unit (1), a repeating unit (4) represented by the following general formula (IV), and a repeating unit (5) represented by the following general formula (V): A resin whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:
(B) Resin of component has positive type photosensitive composition characterized by having at least 1 or more types of repeating units (1)-(5), respectively.

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

In general formula (IV),
R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.
R ₇ represents a group having a lactone structure.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.

In general formula (V),
R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.
[8]
The positive photosensitive composition as described in any one of [1] to [5], wherein the resin as the component (B) further has an acid-decomposable repeating unit (3) different from the repeating unit (1). object.
[9]
The positive electrode according to [7] or [8], wherein the acid-decomposable repeating unit (3) has a group capable of leaving by the action of an acid represented by the following general formulas (pI) to (pV). Type photosensitive composition.

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.
[10]
The positive photosensitive composition as described in [9], wherein the acid-decomposable repeating unit (3) is represented by the following general formula (III-1).

In general formula (III-1),
R represents a hydrogen atom, a halogen atom or an alkyl group. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group, or a group of two or more groups selected from the group consisting of a urea group and a urea group.
Rp ₁ represents any group of the general formulas (pI) to (pV).
[11]
Any of [1] to [6] and [8] to [10], wherein the resin of component (B) further has a repeating unit (4) represented by the following general formula (IV): The positive photosensitive composition described in 1.

In general formula (IV),
R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.
R ₇ represents a group having a lactone structure.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.
[12]
Any of [1] to [6] and [8] to [11], wherein the resin of component (B) further has a repeating unit (5) represented by the following general formula (V): The positive photosensitive composition described in 1.

In general formula (V),
R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.
[13]
The positive type according to any one of [1] to [12], wherein the content of the repeating unit (1) is 5 to 40 mol% with respect to all repeating units in the resin of the component (B). Photosensitive composition.
[14]
The positive type according to any one of [1] to [13], wherein the content of the repeating unit (2) is 1 to 40 mol% with respect to all repeating units in the resin of the component (B). Photosensitive composition.
[15]
Furthermore, the positive photosensitive composition as described in any one of [1] to [14], which contains a mixed solvent of any of the following (S1) to (S5).
(S1) a mixed solvent in which a solvent having a hydroxyl group and a solvent not having a hydroxyl group are mixed;
(S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure;
(S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure;
(S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group;
(S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group.
[16]
The positive photosensitive resin as described in any one of [1] to [15], wherein the amount of the component (B) resin in the entire composition is 60 to 99.0% by mass in the total solid content. Sex composition.
[17]
The positive photosensitive composition as described in any one of [1] to [16], wherein the resin as the component (B) does not have an aromatic group.
[18]
A resist film formed from the positive photosensitive composition as described in any one of [1] to [17].
[19]
[18] A pattern forming method comprising the steps of: forming the resist film as described in [18]; and exposing and developing the film.
[20]
[19] The pattern forming method according to [19], wherein the exposure is immersion exposure.
In addition, although this invention has the structure as described in said [1]-[20], the following was also described for reference below.

(1) (A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a repeating unit (1) represented by the following general formula (I), and an -LR ₃ group (wherein L Is
A divalent linking group having 4 to 30 carbon atoms, wherein R ₃ represents a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group, and is dissolved in an alkali developer by the action of an acid. A positive photosensitive composition comprising a resin having an increased viscosity.

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

  (2) The positive photosensitive composition as described in (1), wherein the repeating unit (2) is represented by the following general formula (II).

In general formula (II):
X represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
L represents a divalent linking group having 4 to 30 carbon atoms.
R ₃ represents a hydrogen atom, a hydroxyl group or an organic group.

  (3) The positive photosensitive composition as described in (1) or (2), wherein the resin of component (B) has two or more types of repeating units (1) represented by general formula (I) object.

  (4) The positive type resin according to any one of (1) to (3), wherein the resin as the component (B) further has an acid-decomposable repeating unit (3) different from the repeating unit (1). Photosensitive composition.

  (5) The positive type as described in (4), wherein the acid-decomposable repeating unit (3) has a group capable of leaving by the action of an acid represented by the following general formulas (pI) to (pV) Photosensitive composition.

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

  (6) The positive photosensitive composition as described in (5), wherein the acid-decomposable repeating unit (3) is represented by the following general formula (III-1).

In general formula (III-1),
R represents a hydrogen atom, a halogen atom or an alkyl group. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group, or a group of two or more groups selected from the group consisting of a urea group and a urea group.
Rp ₁ represents any group of the general formulas (pI) to (pV).

  (7) The positive photosensitive composition as described in (4), wherein the repeating unit (3) is represented by the following general formula (III-2).

In general formula (III-2),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Rya represents an alkyl group or a cycloalkyl group.
Z ₁ represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
Zb represents a divalent linking group.

  (8) The positive resin according to any one of (1) to (7), wherein the resin of component (B) further has a repeating unit (4) represented by the following general formula (IV): Photosensitive composition.

In general formula (IV),
R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.
R ₇ represents a group having a lactone structure.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.

  (9) The positive type resin according to any one of (1) to (8), wherein the resin of component (B) further has a repeating unit (5) represented by the following general formula (V): Photosensitive composition.

In general formula (V),
R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.

  (10) The positive photosensitive composition as described in (9), which has at least one repeating unit (1) to (5).

  (11) A pattern forming method comprising a step of forming a film with the positive photosensitive composition according to any one of (1) to (10), and exposing and developing the film.

  According to the present invention, in forming a fine pattern of 100 nm or less, a positive photosensitive composition having improved pattern collapse, exposure latitude, and line edge roughness, and excellent resist pattern controllability in a thermal flow process, and the same are used. A pattern forming method can be provided.

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

(A) Compound that generates acid upon irradiation with actinic ray or radiation The positive photosensitive composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter also referred to as “acid generator”). contains.
As an acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, or irradiation with actinic ray or radiation used for micro-resist etc. Known compounds that generate acids and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, o-nitrobenzyl sulfonates, and the like.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3, 914, 407, JP 63-26653, JP 55-164824, JP 62-69263, JP 63-1446038, JP 63-163452, JP 62- The compounds described in Japanese Patent No. 153853 and Japanese Patent Application Laid-Open No. 63-146029 can be used.

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

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

In general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Z ⁻ represents a non-nucleophilic anion.

Examples of the non-nucleophilic anion as Z ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

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

The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as methyl. Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group , Tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group and the like.

  The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

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

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

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

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

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

Compound (ZI-1) is at least one of R ₂₀₁ to R ₂₀₃ in formula (ZI) is an aryl group, an aryl sulfonium compounds, i.e., compounds containing an arylsulfonium as a cation.

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

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

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

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

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
The compound (ZI-2) is a compound in which R _{201 to} R ₂₀₃ in the general formula (ZI) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

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

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

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

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.
Any two or more of R _{1c to} R _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 and a sulfur atom. , An ester bond and 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 non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as Z ^{− in} formula (ZI).

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

The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c. Is 2-15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _7c , such as a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

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

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

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

In the general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group. Aryl group R ₂₀₄ to R ₂₀₇ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

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

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

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

  Examples of the acid generator further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

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

Among the acid generators, compounds represented by the general formulas (ZI) to (ZIII) are more preferable.
Further, the acid generator is preferably a compound that generates an acid having one sulfonic acid group or imide group, more preferably a compound that generates monovalent perfluoroalkanesulfonic acid, or a monovalent fluorine atom or fluorine atom. A compound that generates an aromatic sulfonic acid substituted with a group containing fluorinated acid, or a compound that generates a monovalent fluorine atom or imide acid substituted with a group containing a fluorine atom, and even more preferably, It is a sulfonium salt of a substituted alkanesulfonic acid, a fluorine-substituted benzenesulfonic acid, a fluorine-substituted imide acid or a fluorine-substituted methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

  Among acid generators, particularly preferred examples are listed below, but the present invention is not limited thereto.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator in the positive photosensitive composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the positive photosensitive composition. More preferably, it is 1-7 mass%.

(B) Resin whose dissolution rate in an alkaline developer is increased by the action of an acid The resin used in the positive photosensitive composition of the present invention whose dissolution rate in an alkaline developer is increased by the action of an acid is represented by the following general formula ( I) and a repeating unit (1) represented by -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, and R ₃ represents a hydrogen atom, a hydroxyl group or an organic group. And a repeating unit (2) having a group).

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

In the general formula (I), the alkyl group represented by Xa ₁ is preferably an alkyl group having 1 to 5 carbon atoms and may be substituted with a hydroxyl group or a halogen atom.
Xa ₁ is preferably a hydrogen atom or a methyl group.
The alkyl group of Ry ₁ , Ry ₂ and Rx is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, Examples include isopropyl group, butyl group, isobutyl group, t-butyl group and the like.
Ry _1, Ry ₂ and cycloalkyl groups Rx is a monocyclic cycloalkyl group having 3 to 8 carbon atoms, a cycloalkyl group of polycyclic 7-14 carbon atoms preferred. Preferable monocyclic cycloalkyl groups include, for example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclopropyl group and the like. Preferred examples of the polycyclic cycloalkyl group include an adamantyl group, a norbornane group, a tetracyclododecanyl group, a tricyclodecanyl group, a diamantyl group, and the like.
Ry ₁ and Ry ₂ are preferably a methyl group or an ethyl group.
Rx is preferably an alkyl group having 2 or more carbon atoms or a cycloalkyl group. By being an alkyl group having 2 or more carbon atoms or a cycloalkyl group, acid decomposability is improved as compared with a methyl group, and sensitivity and post-heating temperature dependency after exposure are improved.
The alkyl group and cycloalkyl group of Ry ₁ , Ry ₂ and Rx may have a substituent.
The alkylene group for Za is preferably an alkylene group having 1 to 8 carbon atoms. In the alkylene group of Za, a part of the methylene group may be replaced with a linking group having a hetero atom such as an oxygen atom, a sulfur atom, an ester group, or a ketone group. Za is preferably an alkylene group having 1 to 4 carbon atoms, and particularly preferably —CH ₂ —, —CH ₂ CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —. . The alkylene group for Za preferably has no acid leaving property.

  Two or more kinds of the repeating unit (1) represented by the general formula (I) may be contained in the resin of the component (B).

The polymerizable compound for forming the repeating unit (1) represented by the general formula (I) can be easily synthesized by a known method. For example, using a method similar to the method described in JP-A-2005-331918, as shown in the following formula, after reacting an alcohol and a carboxylic acid halide compound under basic conditions, the carboxylic acid compound is converted into a base. It can be synthesized by reacting under sexual conditions.

  Preferred specific examples of the repeating unit (1) represented by the general formula (I) are shown below, but the present invention is not limited thereto.

  The repeating unit (1) is decomposed by the action of an acid to generate a carboxyl group, and the dissolution rate in an alkaline developer is increased.

  The content of the repeating unit (1) is preferably 1 to 60 mol%, more preferably 1 to 50 mol%, still more preferably 5 to 40 mol%, based on all repeating units in the polymer.

The resin of component (B) is a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, and R ₃ represents a hydrogen atom, a hydroxyl group or an organic group). Having repeating unit (2).

The divalent linking group having 4 to 30 carbon atoms of L is preferably a linear or branched alkylene group having 4 to 30 carbon atoms, and more preferably a linear or branched alkylene group having 4 to 20 carbon atoms.
The alkylene group may have a structure having an oxygen atom, a sulfur atom or an ester group in the alkylene chain, that is, a structure in which an alkylene group is bonded via an oxygen atom, a sulfur atom or an ester group.
Examples of the divalent linking group having 4 to 30 carbon atoms of L include (—CH ₂ —) _n (wherein n represents an integer of 4 to 30), (—CH ₂ —CH (Ra) -O-) _m -La- (wherein _m represents an integer of 1 to 15, Ra represents a hydrogen atom or an alkyl group (preferably a methyl group), and La represents a single bond or an alkylene group (preferably a carbon number). 2 to 28)).
In addition, the carbon atom of the ester bond is not included in the carbon number of 4 to 30 in the divalent linking group having 4 to 30 carbon atoms.
Examples of the organic group for R ₃ include a carboxyl group and a cycloalkyl group, and a carboxyl group is particularly preferable.

  The repeating unit (2) is preferably represented by the following general formula (II).

In general formula (II):
X represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
L represents a divalent linking group having 4 to 30 carbon atoms.
R ₃ represents a hydrogen atom, a hydroxyl group or an organic group.

The alkyl group of X is preferably an alkyl group having 1 to 5 carbon atoms and may be substituted with a hydroxyl group or a halogen atom.
The divalent linking group having 4 to 30 carbon atoms of L is preferably a linear or branched alkylene group having 4 to 30 carbon atoms, and more preferably a linear or branched alkylene group having 4 to 20 carbon atoms.
The alkylene group may have a structure having an oxygen atom, a sulfur atom or an ester group in the alkylene chain, that is, a structure in which an alkylene group is bonded via an oxygen atom, a sulfur atom or an ester group.
Examples of the divalent linking group having 4 to 30 carbon atoms of L include (—CH ₂ —) _n (wherein n represents an integer of 4 to 30), (—CH ₂ —CH (Ra) -O-) _m -La- (wherein _m represents an integer of 1 to 15, Ra represents a hydrogen atom or an alkyl group (preferably a methyl group), and La represents a single bond or an alkylene group (preferably a carbon number). 2 to 28)).
In addition, the carbon atom of the ester bond is not included in the carbon number of 4 to 30 in the divalent linking group having 4 to 30 carbon atoms.
Examples of the organic group for R ₃ include a carboxyl group and a cycloalkyl group, and a carboxyl group is particularly preferable.

  Specific examples of the repeating unit (2) represented by the general formula (II) are shown below, but the present invention is not limited thereto.

  The content of the repeating unit (2) is preferably from 1 to 40 mol%, more preferably from 1 to 30 mol%, still more preferably from 5 to 20 mol%, based on all repeating units in the polymer.

The resin of component (B) preferably has an acid-decomposable repeating unit (3) different from the repeating unit (1).
The acid-decomposable repeating unit (3) can be used without particular limitation, but is preferably a repeating unit having a group capable of leaving by the action of an acid represented by the following general formulas (pI) to (pV).

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the general formula (pII), at least one of R _{12 to} R ₁₄ is preferably a cycloalkyl group.
In general formula (pIII), at least one of R ₁₅ and R ₁₆ is preferably a cycloalkyl group.
In general formula (pIV), at least one of R _{17 to} R ₂₁ is preferably a cycloalkyl group.
In the general formula (pV), at least one of R _{22 to} R ₂₅ is preferably a cycloalkyl group.

In the general formulas (pI) to (pV) and R _{11 to} R ₂₅ , the alkyl group is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, n- Examples include propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like.
The cycloalkyl group or the cycloalkyl group formed by Z and the carbon atom in R _{12 to} R ₂₅ may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 5 to 30, and particularly preferably 6 to 25.
Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.
These alkyl groups and cycloalkyl groups may have a further substituent. As further substituents for alkyl groups and cycloalkyl groups, alkyl groups (preferably having 1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (preferably having 1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups ( Preferably C2-C6) etc. are mentioned. Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

The groups represented by the general formulas (pI) to (pV) are used for the protection of alkali-soluble groups to form groups (acid-decomposable groups) that decompose by the action of an acid to generate alkali-soluble groups. Can do. Examples of the alkali-soluble group include various groups known in this technical field.
Specific examples include groups in which hydrogen atoms of carboxylic acid groups, sulfonic acid groups, phenol groups, and thiol groups are substituted with groups represented by general formulas (pI) to (pV), preferably carboxylic acids. Group, a hydrogen atom of a sulfonic acid group is a group substituted by groups represented by general formulas (pI) to (pV).

  As the repeating unit having an alkali-soluble group protected by groups represented by general formulas (pI) to (pV), a repeating unit represented by the following general formula (III-1) is preferable.

In general formula (III-1),
R represents a hydrogen atom, a halogen atom or an alkyl group. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group, or a group of two or more groups selected from the group consisting of a urea group and a urea group.
Rp ₁ represents any group of the general formulas (pI) to (pV).

  Specific examples of the repeating unit represented by formula (III-1) are shown below, but the present invention is not limited thereto.

  Examples of the acid-decomposable repeating unit (3) further include a repeating unit represented by the following general formula (III-2).

In general formula (III-2),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Rya represents an alkyl group or a cycloalkyl group.
Z ₁ represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
Zb represents a divalent linking group.

In formula (III-2), Xa _1, said in the general formula (I), similar to the Xa _1.
Examples of the alkyl group and cycloalkyl group of Rya include Ry ₁ and R in the general formula (I).
Examples are the same as the alkyl group and cycloalkyl group of y ₂ and Rx.
Z ₁ is the same as Z in the general formula (pI).
Examples of the divalent linking group for Zb include linear or branched alkylene groups (preferably having 1 to 5 carbon atoms), cycloalkylene groups (preferably having 7 to 15 carbon atoms), and combinations thereof.

  Specific examples of the repeating unit represented by formula (III-2) are shown below, but the present invention is not limited thereto.

  The content of the acid-decomposable repeating unit (3) is preferably from 0 to 60 mol%, more preferably from 1 to 50 mol%, still more preferably from 5 to 40 mol%, based on all repeating units in the polymer.

The resin of component (B) preferably has a repeating unit having a group having a lactone structure.
As the group having a lactone structure, any group having a lactone structure can be used, but a group having a 5- to 7-membered ring lactone structure is preferable. A structure in which another ring structure is condensed to form a structure or a spiro structure is preferable. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and a specific lactone structure is used. As a result, line edge roughness and development defects are improved.

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

  The repeating unit (4) represented by the following general formula (IV) is preferable as the repeating unit having a group having a lactone structure.

In general formula (IV),
R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.
R ₇ represents a group having a lactone structure.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.

In general formula (IV), the alkyl group represented by R ₆ is preferably an alkyl group having 1 to 4 carbon atoms and may have a substituent. Preferable substituents that the alkyl group of R ₆ may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for R ₆ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
R ₆ is preferably a hydrogen atom or a methyl group.
Ab is preferably a single bond or a linking group represented by —Ab ₁ —CO ₂ —. Ab ₁ is a linear or branched alkylene group or a monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.
R ₇ is preferably a group having a structure represented by any of the general formulas (LC1-1) to (LC1-16).

  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.

  Hereinafter, although the specific example of a repeating unit (4) is shown, this invention is not limited to this.

  Particularly preferred repeating units (4) include the following repeating units. By selecting the optimum lactone structure, the pattern profile and the density dependence become good.

  The content of the repeating unit (4) is preferably from 0 to 60 mol%, more preferably from 1 to 50 mol%, still more preferably from 5 to 40 mol%, based on all repeating units in the polymer.

  The resin of component (B) preferably has a repeating unit (5) represented by the following general formula (V).

In general formula (V),
R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.

The group having an alicyclic hydrocarbon structure in the general formula (V) or R ₉ is preferably an adamantyl group, a diamantyl group, or a norbornane group.
The group having an alicyclic hydrocarbon structure substituted with a preferred hydroxyl group or cyano group is preferably a group represented by the following general formulas (VIIa) to (VIId).

In general formulas (VIIa) to (VIIc),
R _{2c to} R _4c each independently represents a hydrogen atom hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the rest are hydrogen atoms. In general formula (VIIa), more preferably, two of R _{2c to} R _4c are hydroxyl groups and the remaining are hydrogen atoms.

  The content of the repeating unit (5) is preferably from 0 to 40 mol%, more preferably from 1 to 30 mol%, still more preferably from 5 to 25 mol%, based on all repeating units in the polymer.

  Specific examples of the repeating unit (5) are shown below, but the present invention is not limited thereto.

  The resin as the component (B) preferably has one or more repeating units (3) to (5) together with the repeating units (1) and (2).

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

  In the resin of the component (B), the content molar ratio of each repeating unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance required for resolving power and heat resistance. In order to adjust the sensitivity and the like, it is set as appropriate.

  When the positive photosensitive composition of the present invention is for ArF exposure, it is preferable that the resin of the component (B) does not have an aromatic group from the viewpoint of transparency to ArF light.

  As the resin of component (B), preferably, all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate-based repeating units, all of the repeating units may be acrylate-based repeating units, and all of the repeating units may be any mixture of methacrylate-based repeating units / acrylate-based repeating units. .

The resin of component (B) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer and a polymerization initiator are dissolved in a solvent, and a batch polymerization method in which polymerization is performed by heating, a solution of the monomer and the polymerization initiator is dropped into a heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, and amides such as dimethylformamide and dimethylacetamide. Furthermore, the solvent which melt | dissolves the positive photosensitive composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive photosensitive composition of the present invention. Thereby, the generation of particles during storage can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As the polymerization initiator, the polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.). As the radical initiator, an azo-based initiator is preferable, and an azo-based 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, a polymerization initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

The weight average molecular weight of the resin as the component (B) is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and particularly preferably 5,000 to as a polystyrene converted value by the GPC method. 15,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The molecular weight distribution is usually 1 to 5, preferably 1 to 3, and more preferably 1 to 2. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.

In the positive photosensitive composition of the present invention, the blending amount of the resin as the component (B) in the entire composition is preferably 50 to 99.99% by mass, more preferably 60 to 99.0% by mass in the total solid content. %.
In the present invention, the resin of component (B) may be used alone or in combination.

(C) A dissolution control compound having a molecular weight of 3000 or less, having at least one selected from an alkali-soluble group, a hydrophilic group, and an acid-decomposable group. The positive photosensitive composition of the present invention includes an alkali-soluble group, a hydrophilic group, and an acid. A dissolution controlling compound having a molecular weight of 3000 or less (hereinafter also referred to as “solubility controlling compound”) having at least one selected from degradable groups may be added.
Examples of the dissolution control compound include a carboxyl group, a sulfonylimide group, a compound having an alkali-soluble group such as a hydroxyl group substituted at the α-position with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, a pyrrolidone group, a sulfone group. A compound having a hydrophilic group such as an amide group and a compound having a group capable of decomposing by the action of an acid and releasing an alkali-soluble group or a hydrophilic group are preferred. The group capable of decomposing by the action of an acid and releasing an alkali-soluble group or a hydrophilic group is preferably a group in which a carboxyl group or a hydroxyl group is protected with a group capable of leaving by the action of an acid. As the dissolution control compound, it is preferable to use a compound that does not contain an aromatic ring or to use a compound having an aromatic ring in an addition amount of 20 wt% or less with respect to the solid content of the composition in order not to lower the permeability of 220 nm or less. .
Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornane carboxylic acid, cholic acid, or the like, compounds in which the carboxylic acid is protected with an acid-decomposable group, saccharides, and the like. A polyol or a compound obtained by protecting the hydroxyl group with an acid-decomposable group is preferred.
The molecular weight of the dissolution controlling compound is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.
The addition amount of the dissolution control compound is preferably 3 to 40% by mass, more preferably 5 to 20% by mass, based on the solid content of the positive photosensitive composition.

  Although the specific example of a solubility control compound is shown below, this invention is not limited to these.

Basic Compound The positive photosensitive composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating.
Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring. R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
The alkyl groups in the general formulas (A) and (E) are more preferably unsubstituted.

  Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and 2-phenylbenzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undecar 7-ene etc. are mentioned. Examples of the compound having an onium hydroxide structure include tetrabutylammonium hydroxide, triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris ( and t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, 2-oxopropylthiophenium hydroxide, and the like. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, N-phenyldiethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

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

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

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

In the amine compound having a sulfonic acid ester group and the ammonium salt compound having a sulfonic acid ester group, the sulfonic acid ester group may be any of alkyl sulfonic acid ester, cycloalkyl group sulfonic acid ester, and aryl sulfonic acid ester. In the case of an alkyl sulfonate ester, the alkyl group has 1 to 20 carbon atoms, in the case of a cycloalkyl sulfonate ester, the cycloalkyl group has 3 to 20 carbon atoms, and in the case of an aryl sulfonate ester, the aryl group has 6 carbon atoms. ~ 12 are preferred. Alkyl sulfonic acid ester, cycloalkyl sulfonic acid ester, and aryl sulfonic acid ester may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid. An ester group is preferred.
It is preferable to have at least one oxyalkylene group between the sulfonate group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  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% normally on the basis of solid content of a positive photosensitive composition, Preferably it is 0.01-5 mass%.

  The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, still more preferably 7.0 to 150.

(E) Fluorine and / or silicon-based surfactant The positive photosensitive composition of the present invention further comprises fluorine and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant and fluorine atom). It is preferable to contain any one or two or more surfactants having both silicon atoms.

  When the positive photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, the adhesiveness and the resolution can be improved with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A resist pattern with few development defects can be provided.

Examples of the fluorine and / or silicon surfactant include, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, Japanese Unexamined Patent Publication No. 63-34540, Japanese Unexamined Patent Publication No. 7-230165, Japanese Unexamined Patent Publication No. 8-62834, Japanese Unexamined Patent Publication No. 9-54432, Japanese Unexamined Patent Publication No. 9-5988, Japanese Unexamined Patent Publication No. 2002-277862, US Patent 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Activators can be mentioned, and the following commercially available surfactants can be used as they are.

Examples of commercially available surfactants that can be used include EFTOP EF301, EF303, (
Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (Sumitomo 3M Co., Ltd.), MegaFuck F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, Fluorosurfactants or silicon surfactants such as 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.) can be used. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon surfactant.

  In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, the copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups. Alternatively, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

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

  The amount of fluorine and / or silicon-based surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive photosensitive composition (excluding the solvent). %.

Organic Solvent The positive photosensitive composition of the present invention is used by dissolving each component in a predetermined organic solvent.
Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent containing two or more solvents having different functional groups. As a result, the solubility of the material is increased, and not only the generation of particles over time can be suppressed, but also the generation of defects during application can be suppressed, and a good pattern profile can be obtained. Preferable functional groups possessed by the solvent include ester groups, lactone groups, hydroxyl groups, ketone groups, carbonate groups and the like. As the mixed solvent having different functional groups, the following mixed solvents (S1) to (S5) are preferable.
(S1) a mixed solvent in which a solvent having a hydroxyl group and a solvent not having a hydroxyl group are mixed;
(S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure;
(S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure;
(S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group;
(S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group.

Examples of the solvent having a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Propylene glycol monomethyl ether and ethyl lactate are particularly preferred.
Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are preferable, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate 2-heptanone and cyclohexanone are more preferred.
Examples of the solvent having a ketone structure include cyclohexanone and 2-heptanone, and cyclohexanone is preferable.
Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.
Examples of the solvent having a lactone structure include γ-butyrolactone.
Examples of the solvent having a carbonate structure include propylene carbonate and ethylene carbonate, and propylene carbonate is preferable.

The mixing ratio (mass) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is usually 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 20/80 to 60/40. A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is particularly preferable from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a ketone structure is usually 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 40/60 to 80/20. A mixed solvent containing 50% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a lactone structure is usually 70/30 to 99/1, preferably 80/20 to 99/1, and more preferably 90/10 to 99 /. 1. A mixed solvent containing 70% by mass or more of a solvent having an ester structure is particularly preferable in terms of stability over time.
When mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a lactone structure is 1 to 20% by mass, and the hydroxyl group is It is preferable to contain 10-60 mass% of the solvent which has.
When mixing the solvent having an ester structure, the solvent having a carbonate structure, and the solvent having a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a carbonate structure is 1 to 20% by mass, and the hydroxyl group is It is preferable to contain 10-60 mass% of the solvent which has.

(Pattern formation method)
The positive photosensitive composition of the present invention is used by dissolving each component in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and even more preferably 0.03 microns or less.

  Arbitrary thickness (usually 50 to 500 nm) by an appropriate coating method such as a spinner or a coater on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device with a positive photosensitive composition. Apply with. After application, the resist film is formed by drying by spinning or baking. The baking temperature can be set as appropriate, but is usually 60 to 150 ° C, and preferably 90 to 130 ° C.

Next, exposure is performed through a mask or the like for pattern formation.
Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally. After exposure, preferably, spinning or / and baking is performed, development and rinsing are performed to obtain a pattern.

  Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. In addition, an overcoat layer may be further provided on the photosensitive film in order to prevent the immersion medium and the photosensitive film from directly contacting each other during the immersion exposure. Thereby, the elution of the composition from the photosensitive film to the immersion medium is suppressed, and development defects are reduced.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ excimer laser, EUV (13 nm) An electron beam is preferred.

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

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

In the resist pattern forming method of the present invention, a thermal flow treatment can be further performed after the resist pattern is formed.
The thermal flow treatment can be performed as follows, for example.
That is, the resist pattern after the development treatment is softened by heating at least once, preferably 2-3 times, and the resist is allowed to flow, whereby the resist pattern pattern size (for example, the hole pattern hole diameter and the line and space width) ) Is reduced (narrower) than the size immediately after development.
A suitable heating temperature depends on the composition of the positive photosensitive composition and is not particularly limited as long as it is not lower than the softening point of the resist pattern, but is preferably in the range of 80 to 180 ° C, more preferably in the range of 110 to 170 ° C. More preferably, it is 130-170 degreeC. By setting the heating temperature within this range, there are advantages such as easy control of the pattern size and ease of use in existing apparatuses.
Further, a suitable heating time is not particularly limited as long as it is within a range in which a desired pattern size can be obtained without hindering throughput, but one time can be determined from a normal semiconductor element manufacturing line process. The heating is preferably performed for 10 to 300 seconds, more preferably about 30 to 180 seconds.

The positive photosensitive composition of the present invention may be applied to an upper resist layer of a multilayer resist process (particularly a three-layer resist process). The multilayer resist method includes the following processes.
(A) A lower resist layer made of an organic material is formed on a substrate to be processed.
(B) An intermediate layer and an upper resist layer are sequentially laminated on the lower resist layer.
(C) After forming a predetermined pattern in the upper resist layer, the intermediate layer, the lower layer and the substrate are sequentially etched.
As the intermediate layer, organopolysiloxane (silicone resin) or SiO ₂ coating solution (SOG) is generally used. As the lower layer resist, an appropriate organic polymer film is used,
Various known photoresists may be used. For example, each series of the Fuji Film Arch FH series, FHi series, or Sumitomo Chemical PFI series can be illustrated.
The film thickness of the lower resist layer is preferably 0.1 to 4.0 μm, more preferably 0.2 to 2.0 μm, and particularly preferably 0.25 to 1.5 μm. A thickness of 0.1 μm or more is preferable from the viewpoint of antireflection and dry etching resistance, and a thickness of 4.0 μm or less is preferable from the viewpoint of aspect ratio and pattern collapse of the formed fine pattern.

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

Synthesis example 1
Under a nitrogen stream, 43 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. Γ-butyrolactone methacrylate 6.8 g, 3-hydroxyadamantyl-1-methacrylate 2.36 g, the following monomer (A) 12.8 g, methoxyethoxyethyl methacrylate 1.88 g, polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) Was added dropwise over 6 hours to a solution prepared by dissolving 4.5 mol% of the monomer in 82 g of cyclohexanone. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise to a mixed solution of 900 m of methanol / 100 ml of water over 20 minutes. The precipitated powder was collected by filtration and dried to obtain 20 g of Resin (P-1). The weight average molecular weight of the obtained resin (P-1) was 11000 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.65.

  Other resins (P-2) to (P-16) were synthesized using the same method. The weight average molecular weight was adjusted by changing the amount of the polymerization initiator.

  Hereinafter, the structures of the resins (P-1) to (P-16) are shown.

Examples 1-14 and Comparative Examples 1-2
<Resist preparation>
The components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content concentration of 5% by mass, and this was filtered through a polyethylene filter having a pore size of 0.03 μm to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are also shown in Table 1.
<Resist evaluation>
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 78 nm. The prepared positive resist composition was applied thereon and baked at 110 ° C. for 60 seconds to form a resist film having a thickness of 160 nm. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Annular (σo / σi = 0.89 / 0.65) manufactured by ASML). Thereafter, heating was performed at 110 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
Pattern collapse evaluation method:
When the exposure amount that reproduces the 85nm line and space mask pattern is set as the optimal exposure amount and the line width of the line pattern formed by further increasing the exposure amount from the optimal exposure amount is reduced, the pattern does not collapse. It was defined by the line width to be resolved. A smaller value indicates that a finer pattern is resolved without falling, and pattern falling is less likely to occur.
Exposure latitude evaluation method:
The exposure amount that reproduces the 85 nm line and space mask pattern is the optimum exposure amount, and when the exposure amount is changed, an exposure amount width that allows a pattern size of 85 nm ± 10% is obtained, and this value is divided by the optimum exposure amount. Percentages. The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure latitude.
Line edge roughness evaluation method:
The line edge edge roughness is measured by using a length-measuring scanning electron microscope (SEM) to observe an isolated pattern of 120 nm, and the distance from the reference line where the edge of the line pattern should be in the range of 5 μm in the longitudinal direction. Was measured with a length measurement SEM (Hitachi, Ltd. S-9260) to obtain a standard deviation, and 3σ was calculated. A smaller value indicates better performance.
Thermal flow suitability evaluation method:
After forming an 85 nm line and space pattern, each was baked at 150 ° C., 160 ° C., and 170 ° C. for 90 seconds, and the shrinkage of the line width was measured with a length measurement SEM (Hitachi, Ltd. S-9260). Among the three measured temperatures, the lowest temperature contracted 10% or more than the original line width is 150 ° C. ◎, 160 ° C. ○, 170 ° C. Δ, 170 ° C. is 10% more than the original line width. The case where shrinkage of more than% was not observed was evaluated as x.

  Hereinafter, abbreviations in the table are shown.

  [Acid generator]

[Basic compounds]
TPSA: Triphenylsulfonium acetate
DIA: 2,6-diisopropylaniline TEA: triethanolamine DBA: N, N-dibutylaniline PBI: 2-phenylbenzimidazole TMEA: tris (methoxyethoxyethyl) amine PEA: N-phenyldiethanolamine PBMA: 2- [2- {2- (2,2-dimethoxy-phenoxyethoxy) ethyl} -bis- (2-methoxyethyl)]-amine [surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based) W-4: Troysol S-366 (manufactured by Troy Chemical Co., Ltd.)
〔solvent〕
S1: Propylene glycol methyl ether acetate
S4: γ-butyrolactone
S5: Propylene glycol methyl ether
S6: Ethyl lactate

  From Table 1, it can be seen that the positive photosensitive composition of the present invention is excellent in pattern collapse, exposure latitude, line edge roughness, and thermal flow evaluation.

Example 15
<Resist preparation>
0.05 g of the following polymer (A) is further added to the components of Example 1 to prepare a solution having a solid content concentration of 5% by mass, and this is filtered through a polyethylene filter having a pore size of 0.1 μm to form a positive resist solution. Was prepared. The prepared positive resist solution was evaluated by the following method.

<Resolution evaluation>
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 78 nm. A positive resist solution prepared thereon was applied and baked at 110 ° C. for 60 seconds to form a resist film having a thickness of 160 nm.
The wafer thus obtained was subjected to pattern exposure using an ArF excimer laser immersion scanner (NA 0.75). As the immersion liquid, ultrapure water having impurities of 5 ppb or less was used. Immediately after the exposure, the resist pattern obtained by heating at 115 ° C. for 90 seconds, developing with an aqueous tetramethylammonium hydroxide solution (2.38%) for 60 seconds, rinsing with pure water, and spin drying is then applied to a scanning electron microscope. When observed using Hitachi S-9260, a 65 nm line and space pattern was resolved.
The positive photosensitive composition of the present invention had a good image forming ability even in an exposure method using an immersion liquid.

Claims (20)

(A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a repeating unit (1) represented by the following general formula (I) and the following general formula (II) different from the repeating unit (1) A positive photosensitive composition comprising a resin having a repeating unit (2) represented by formula (I) and having a dissolution rate increased in an alkaline developer by the action of an acid.

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

In the formula, L represents a linear or branched alkylene group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group or an organic group, and X represents a hydrogen atom, an alkyl group, a cyano group or a halogen. Represents an atom.   R in the general formula (II) ₃ Is a carboxyl group or a cycloalkyl group, The positive photosensitive composition according to claim 1, wherein   (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) a repeating unit (1) represented by the following general formula (I ′), and —LR _Three Group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R _Three Is a resin having a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group, and whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:

  In the general formula (I ′),
  Xa ₁ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  Ry ₁ And Ry ₂ Each independently represents an alkyl group or a cycloalkyl group.
  Rx ′ represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group. However, the alkyl group as Rx ′ is unsubstituted alkyl.
  Za 'represents an unsubstituted alkylene group having 1 to 4 carbon atoms.   (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) a repeating unit (1) represented by the following general formula (I), and -LR _Three Group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R _Three Is a resin having a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group, and whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:
A positive photosensitive composition further containing a resin having a repeating unit represented by the following general formula (A) different from the resin of component (B).

  In general formula (I),
  Xa ₁ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  Ry ₁ , Ry ₂ And Rx each independently represents an alkyl group or a cycloalkyl group.
  Za represents an alkylene group.   (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) a repeating unit (1) represented by the following general formula (I), and -LR _Three Group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R _Three Is a resin having a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group, and whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:
The positive photosensitive composition, wherein the resin of component (B) has two or more types of repeating units (1) represented by general formula (I).

  In general formula (I),
  Xa ₁ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  Ry ₁ , Ry ₂ And Rx each independently represents an alkyl group or a cycloalkyl group.
  Za represents an alkylene group.   (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) a repeating unit (1) represented by the following general formula (I), and -LR _Three Group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R _Three Is a resin having a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group, and whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:
The positive photosensitive composition characterized in that the resin of component (B) further has an acid-decomposable repeating unit represented by the following general formula (III-2).

  In general formula (I),
  Xa ₁ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  Ry ₁ , Ry ₂ And Rx each independently represents an alkyl group or a cycloalkyl group.
  Za represents an alkylene group.

  In general formula (III-2),
  Xa ₁ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  Rya represents an alkyl group or a cycloalkyl group.
  Z ₁ Represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
  Zb represents a divalent linking group. (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and
(B) Repeating unit (1) represented by the following general formula (I) and -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ is A repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group),
An acid-decomposable repeating unit (3) different from the repeating unit (1), a repeating unit (4) represented by the following general formula (IV), and a repeating unit (5) represented by the following general formula (V): A resin whose dissolution rate in an alkaline developer is increased by the action of an acid.
A positive photosensitive composition comprising:
(B) Resin of component has positive type photosensitive composition characterized by having at least 1 or more types of repeating units (1)-(5), respectively .

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.
Za represents an alkylene group.

In general formula (IV),
R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.
R ₇ represents a group having a lactone structure.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.

In general formula (V),
R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The resin as the component (B), further, the positive photosensitive composition according to any one of claims 1 to 5, characterized by having a repeating unit (1) different acid-decomposable repeating unit (3). The positive photosensitive layer according to claim 7 or 8 , wherein the acid-decomposable repeating unit (3) has a group capable of leaving by the action of an acid represented by the following general formulas (pI) to (pV). Sex composition.

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring. The positive photosensitive composition according to claim 9 , wherein the acid-decomposable repeating unit (3) is represented by the following general formula (III-1).

In general formula (III-1),
R represents a hydrogen atom, a halogen atom or an alkyl group. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group, or a group of two or more groups selected from the group consisting of a urea group and a urea group.
Rp ₁ represents any group of the general formulas (pI) to (pV). The positive photosensitive resin according to any one of claims 1 to 6, and 8 to 10 , wherein the resin of component (B) further has a repeating unit (4) represented by the following general formula (IV): Sex composition.

In general formula (IV),
R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.
R ₇ represents a group having a lactone structure.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these. The positive photosensitive resin according to any one of claims 1 to 6 and 8 to 11 , wherein the resin of component (B) further has a repeating unit (5) represented by the following general formula (V). Sex composition.

In general formula (V),
R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.   The positive photosensitive property according to claim 1, wherein the content of the repeating unit (1) is 5 to 40 mol% with respect to all repeating units in the resin of the component (B). Composition.   The positive photosensitive property according to claim 1, wherein the content of the repeating unit (2) is 1 to 40 mol% with respect to all repeating units in the resin of the component (B). Composition.   The positive photosensitive composition according to claim 1, further comprising a mixed solvent of any of the following (S1) to (S5).
(S1) a mixed solvent in which a solvent having a hydroxyl group and a solvent not having a hydroxyl group are mixed;
  (S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure;
  (S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure;
  (S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group;
  (S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group.   The positive photosensitive composition according to any one of claims 1 to 15, wherein the blending amount of the component (B) resin in the entire composition is 60 to 99.0 mass% in the total solid content. object.   The positive photosensitive composition according to claim 1, wherein the resin of component (B) does not have an aromatic group. A resist film formed from the positive photosensitive composition according to claim 1. A pattern forming method comprising: forming the resist film according to claim 18 ; and exposing and developing the film. The pattern forming method according to claim 19, wherein the exposure is immersion exposure.