JP4871718B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive resist composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and also in a lithography process for other photo applications, and a pattern forming method using the same. It is. In particular, the present invention relates to a positive resist composition suitable for exposure with an immersion projection exposure apparatus using far ultraviolet light having a wavelength of 300 nm or less as a light source, and a pattern forming method using the same.

With the miniaturization of semiconductor elements, the exposure light source has become shorter in wavelength and the projection lens has a higher numerical aperture (high NA). Currently, an exposure machine with NA 0.84 using an ArF excimer laser having a 193 nm wavelength as a light source has been developed. ing. These can be expressed by the following equations as is generally well known.
(Resolving power) = k ₁ · (λ / NA)
(Depth of focus) = ± k ₂ · λ / NA ²
Where λ is the wavelength of the exposure light source, NA is the numerical aperture of the projection lens, and k ₁ and k ₂ are coefficients related to the process.

An exposure machine using a F ₂ excimer laser having a wavelength of 157 nm as a light source has been studied for higher resolution by further shortening the wavelength. Lens materials and resists used in the exposure apparatus for shorter wavelength have been studied. Because the materials used in the process are very limited, it is very difficult to stabilize the manufacturing cost and quality of the apparatus and materials, and the exposure apparatus and resist that have sufficient performance and stability within the required period are not in time. The possibility is coming out.

As a technique for increasing the resolving power in an optical microscope, a so-called immersion method in which a high refractive index liquid (hereinafter also referred to as “immersion liquid”) is filled between a projection lens and a sample is known.
This “immersion effect” means that when λ ₀ is the wavelength of the exposure light in the air, n is the refractive index of the immersion liquid with respect to air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. The above-described resolving power and depth of focus can be expressed by the following equations.
(Resolving power) = k ₁ · (λ ₀ / n) / NA ₀
(Depth of focus) = ± k ₂ · (λ ₀ / n) / NA ₀ ²
That is, the immersion effect is equivalent to using an exposure wavelength having a wavelength of 1 / n. In other words, in the case of a projection optical system with the same NA, the depth of focus can be increased n times by immersion. This is effective for all pattern shapes, and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method which are currently being studied.

Examples of apparatuses in which this effect is applied to the transfer of a fine image pattern of a semiconductor element are introduced in Patent Document 1 (Japanese Patent Laid-Open No. 57-153433), Patent Document 2 (Japanese Patent Laid-Open No. 7-220990), and the like. Yes.
Recent progress in immersion exposure technology is described in Non-Patent Document 1 (SPIE Proc 4688, 11 (2002)), Non-Patent Document 2 (J. Vac. Sci. Tecnol. B 17 (1999)), Non-Patent Document 3 (SPIE Proc 3999,2 (2000)), Patent Document 3 (International Publication WO 2004-077158 Pamphlet) 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 considered to be most promising as an immersion liquid in terms of handling safety, transmittance at 193 nm, and refractive index. When an F ₂ excimer laser is used as a light source, a solution containing fluorine has been studied from the balance between transmittance and refractive index at 157 nm. However, a sufficient product has not yet been seen in terms of environmental safety and refractive index. It has not been issued. From the degree of immersion effect and the degree of completeness of the resist, the immersion exposure technique is considered to be installed in the ArF exposure machine earliest.

Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. Explaining by taking a positive chemical amplification image forming method as an example, the acid generator in the exposed area is decomposed by exposure to generate an acid upon exposure, and the generated acid is reacted as a reaction catalyst by post exposure baking (PEB). Is used to change an alkali-insoluble group to an alkali-soluble group, and an exposed portion is removed by alkali development.
Although the resist for ArF excimer laser (wavelength 193 nm) using this chemical amplification mechanism is becoming mainstream at present, further improvement is required for profile and pattern collapse.

In addition, when a chemically amplified resist is applied to immersion exposure, the resist layer comes into contact with the immersion liquid at the time of exposure, so that the resist layer is altered and components that adversely affect the immersion liquid are leached from the resist layer. Has been pointed out. Patent Document 4 (International Publication WO 2004-068242 Pamphlet) describes an example in which resist performance changes by immersing a resist for ArF exposure in water before and after exposure, and points to a problem in immersion exposure. .
In the immersion exposure process, when exposure is performed using a scanning immersion exposure machine, the exposure speed decreases unless the immersion liquid moves following the movement of the lens. Concerned about giving. In the case where the immersion liquid is water, it is desirable that the resist film is hydrophobic and has good water followability.

JP-A-57-153433 JP-A-7-220990 International Publication WO2004-077158 Pamphlet International Publication WO 2004-068242 Pamphlet Proc. SPIE, 2002, Vol. 4688, p. 11 J.Vac.Sci.Tecnol.B 17 (1999) Proc. SPIE, 2000, Vol. 3999, p. 2

  An object of the present invention is to provide a positive resist composition with improved profile and pattern collapse and a pattern forming method using the same. Also provided are a positive resist composition suitable for immersion exposure and a pattern formation method using the same, in which the profile and pattern collapse do not change in immersion exposure and the followability to water is good. It is.

一般式（Ｃ）に於いて、
Ｘ ₁ 、Ｘ ₂ 及びＸ ₃ は、各々独立に、水素原子、アルキル基又はハロゲン原子を表す。
Ｌは、単結合又は２価の連結基を表す。
Ｒｐ ₁ は、酸分解性基を表す。
樹脂Ａは、下記に示すモノマーの重合により得られる樹脂である。

＜２＞ 一般式（Ｃ）が、下記一般式（Ｃ１）であることを特徴とする上記＜１＞に記載のポジ型レジスト組成物。

一般式（Ｃ１）に於いて、
Ｘ ₁ 、Ｘ ₂ 及びＸ ₃ は、各々独立に、水素原子、アルキル基又はハロゲン原子を表す。
Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ は、各々独立に、アルキル基、シクロアルキル基、アルケニル基若しくはアリール基又はこれらの基が結合した１価の基を表す。但し、Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ の内の少なくとも１つは、アルキル基を表す。Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ の内の２つが、結合して環を形成してもよい。
＜３＞ 一般式（Ｃ１）に於いて、Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ が、各々独立に、アルキル基又はアルケニル基を表し、且つ、Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ の内の少なくとも１つが、アルキル基を表すことを特徴とする上記＜２＞に記載のポジ型レジスト組成物。
＜４＞ （Ｃ）成分の樹脂が、全繰り返し単位中に、下記一般式（Ｃ１）で表される繰り返し単位及び下記一般式（Ｃ２）で表される繰り返し単位を８０〜１００モル％有することを特徴とする上記＜１＞〜＜３＞のいずれか一項に記載のポジ型レジスト組成物。

一般式（Ｃ１）及び（Ｃ２）に於いて、
Ｘ ₁ 、Ｘ ₂ 、Ｘ ₃ 、Ｘ ₄ 、Ｘ ₅ 及びＸ ₆ は、各々独立に、水素原子、アルキル基又はハロゲン
原子を表す。
Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ は、各々独立に、アルキル基、シクロアルキル基、アルケニル基若
しくはアリール基又はこれらの基が結合した１価の基を表す。但し、Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄
の内の少なくとも１つは、アルキル基を表す。Ｒ ₁₂ 、Ｒ ₁₃ 及びＲ ₁₄ の内の２つが、結合し
て環を形成してもよい。
Ｌ ₁ は、単結合又は２価の連結基を表す。
Ｒｐ ₂ は、非酸分解性基を表す。
ｍ及びｎは、夫々、繰り返し単位のモル比を表し、ｍ＝１０〜１００、ｎ＝０〜９０、
ｍ＋ｎ＝１００である。
＜５＞ Ｒｐ ₂ は、直鎖又は分岐状のアルキル基、シクロアルキル基、アリール基及びアルケニル基から選ばれる非酸分解性基を表すことを特徴とする上記＜４＞に記載のポジ型レジスト組成物。
＜６＞ （Ｃ）成分の樹脂が、珪素原子及びフッ素原子を有さないことを特徴とする上記＜１＞〜＜５＞のいずれか一項に記載のポジ型レジスト組成物。
＜７＞ （Ａ）成分の樹脂が、少なくとも、ラクトン構造を有する（メタ）アクリレート系繰り返し単位及び酸分解性基を有する（メタ）アクリレート系繰り返し単位の２種類の繰り返し単位を有することを特徴とする上記＜１＞〜＜６＞のいずれか一項に記載のポジ型レジスト組成物。
＜８＞ （Ａ）成分の樹脂が、下記一般式（Ａ１）で表される繰り返し単位、下記一般式（Ａ２）で表される繰り返し単位及び下記一般式（Ａ３）で表される繰り返し単位を有することを特徴とする上記＜１＞〜＜７＞のいずれか一項に記載のポジ型レジスト組成物。

一般式（Ａ１）〜（Ａ３）に於いて、
Ｘａ、Ｘｂ及びＸｃは、各々独立に、水素原子又はメチル基を表す。
Ｒ ₁ は、ラクトン構造を有する１価の有機基を表す。
Ｒ ₂ は、水酸基又はシアノ基を有する１価の有機基を表す。
Ｒ ₃ は、酸の作用により脱離する基を表す。
＜９＞ 上記＜１＞〜＜８＞のいずれか一項に記載のポジ型レジスト組成物により形成したレジスト膜。
＜１０＞ 上記＜９＞に記載のレジスト膜を、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。
＜１１＞ 液浸液を介して露光することを特徴とする上記＜１０＞に記載のパターン形成方法。
＜１２＞ （Ａ）単環又は多環の脂環炭化水素構造を有する、酸の作用によりアルカリ現像液に対する溶解度が増大する樹脂、
（Ｂ）活性光線又は放射線の照射により酸を発生する化合物、
（Ｃ）下記一般式（Ｃ）で表される繰り返し単位を有する樹脂（但し、下記樹脂Ａを除く）及び
（Ｄ）溶剤
を含有し、且つ、（Ｃ）成分の樹脂の含有量が、ポジ型レジスト組成物の固形分を基準にして０．１〜５質量％であるポジ型レジスト組成物によりレジスト膜を形成し、液浸液を介して露光、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。

一般式（Ｃ）に於いて、
Ｘ ₁ 、Ｘ ₂ 及びＸ ₃ は、各々独立に、水素原子、アルキル基又はハロゲン原子を表す。
Ｌは、単結合又は２価の連結基を表す。
Ｒｐ ₁ は、酸分解性基を表す。
樹脂Ａは、下記に示すモノマーの重合により得られる樹脂である。

本発明は、上記＜１＞〜＜１２＞に記載の発明であるが、以下、他の事項も含めて記載している。 The present invention is a positive resist composition having the following constitution and a pattern forming method using the same, whereby the above object of the present invention is achieved.
<1> (A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) A resin having a repeating unit represented by the following general formula (C) (excluding a resin in which an alicyclic hydrocarbon group having a ketone group is substituted on a side chain and the following resin A) and
(D) Solvent
And a content of the resin as the component (C) is 0.1 to 5% by mass based on the solid content of the positive resist composition.

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.
Resin A is a resin obtained by polymerization of monomers shown below.

<2> The positive resist composition as described in <1> above, wherein the general formula (C) is the following general formula (C1).

In general formula (C1),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring.
<3> In the general formula (C1), R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group or an alkenyl group, and at least one of R ₁₂ , R ₁₃ and R ₁₄ is The positive resist composition as described in <2> above, wherein the positive resist composition represents an alkyl group.
<4> The resin of component (C) has 80 to 100 mol% of the repeating unit represented by the following general formula (C1) and the repeating unit represented by the following general formula (C2) in all repeating units. The positive resist composition as described in any one of <1> to <3> above.

In the general formulas (C1) and (C2),
X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ are each independently a hydrogen atom, alkyl group or halogen
Represents an atom.
R ₁₂ , R ₁₃ and R ₁₄ are each independently an alkyl group, cycloalkyl group, alkenyl group or
Alternatively, it represents an aryl group or a monovalent group to which these groups are bonded. However, R ₁₂ , R ₁₃ and R ₁₄
At least one of represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ are bonded
To form a ring.
L ₁ represents a single bond or a divalent linking group.
Rp ₂ represents a non-acid-decomposable group.
m and n each represent a molar ratio of repeating units, m = 10 to 100, n = 0 to 90,
m + n = 100.
<5> Rp ₂ represents a non-acid-decomposable group selected from linear or branched alkyl groups, cycloalkyl groups, aryl groups, and alkenyl groups, The positive resist according to the above <4>, Composition.
<6> The positive resist composition according to any one of <1> to <5>, wherein the resin as the component (C) does not have a silicon atom or a fluorine atom.
<7> The resin of the component (A) has at least two types of repeating units of a (meth) acrylate-based repeating unit having a lactone structure and a (meth) acrylate-based repeating unit having an acid-decomposable group. The positive resist composition according to any one of <1> to <6> above.
<8> The resin of component (A) is a repeating unit represented by the following general formula (A1), a repeating unit represented by the following general formula (A2), and a repeating unit represented by the following general formula (A3). The positive resist composition according to any one of <1> to <7>, wherein the positive resist composition is characterized by comprising:

In the general formulas (A1) to (A3),
Xa, Xb and Xc each independently represent a hydrogen atom or a methyl group.
R ₁ represents a monovalent organic group having a lactone structure.
R ₂ represents a monovalent organic group having a hydroxyl group or a cyano group.
R ₃ represents a group capable of leaving by the action of an acid.
<9> A resist film formed from the positive resist composition according to any one of <1> to <8>.
<10> A pattern forming method comprising a step of exposing and developing the resist film according to <9>.
<11> The pattern forming method according to <10>, wherein the exposure is performed through an immersion liquid.
<12> (A) A resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, the solubility of which is increased in an alkali developer by the action of an acid,
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a resin having a repeating unit represented by the following general formula (C) (excluding the following resin A) and
(D) Solvent
And a resist film is formed with a positive resist composition in which the content of the resin of component (C) is 0.1 to 5% by mass based on the solid content of the positive resist composition, A pattern forming method comprising a step of exposing and developing through an immersion liquid.

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.
Resin A is a resin obtained by polymerization of monomers shown below.

The present invention is the invention described in <1> to <12> above, but is described below including other matters.

(1) (A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a resin having a repeating unit represented by the following general formula (C) and (D) a solvent, and the content of the resin as the component (C) is based on the solid content of the positive resist composition A positive resist composition characterized by being 0.1 to 20% by mass.

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.

(2) (A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a resin having a repeating unit represented by the following general formula (C) and (D) a solvent, and the content of the resin as the component (C) is based on the solid content of the positive resist composition A positive resist composition characterized by being 0.1 to 5% by mass.

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.

  (3) The positive resist composition as described in (1) or (2), wherein the general formula (C) is the following general formula (C1).

In general formula (C1),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring.

(4) In the general formula (C1), R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group or an alkenyl group, and at least one of R ₁₂ , R ₁₃ and R ₁₄ is The positive resist composition as described in (3), wherein the positive resist composition represents an alkyl group.

  (5) The resin of component (C) has 80 to 100 mol% of the repeating unit represented by the following general formula (C1) and the repeating unit represented by the following general formula (C2) in all repeating units. The positive resist composition as described in any one of (1) to (4) above.

In the general formulas (C1) and (C2),
X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring.
L ₁ represents a single bond or a divalent linking group.
Rp ₂ represents a non-acid-decomposable group.
m and n respectively represent the molar ratio of the repeating units, and m = 10 to 100, n = 0 to 90, and m + n = 100.

  (6) The resin of the component (C) is a repeating unit selected from the following general formulas (CI) to (C-IV) in all repeating units (however, represented by the general formula (CI)) Any one of (1) to (4), wherein the repeating unit and the repeating unit represented by the general formula (C-II) are used in a combination of 80 mol% to 100 mol%. The positive resist composition as described in 1. above.

In the general formulas (C-I) to (C-IV),
R ₁ represents a hydrogen atom or a methyl group.
When there are a plurality of R _{2 s} , each R ₂ independently represents a hydrocarbon group having at least two partial structures of —CH ₃ .
P ₁ represents a single bond, an alkylene group or an ether group, or a linking group in which two or more of them are bonded.
P ₂ represents a linking group selected from —O—, —NR— (R represents a hydrogen atom or an alkyl group) and —NHSO ₂ —.
x1, x2, y, and z represent mol% in all repeating units, x1 represents 0 to 50, x2 represents 0 to 50, y represents 0 to 100, and z represents 0 to 100. However, 80 ≦ x1 + x2 + y + z ≦ 100 is satisfied.
n represents an integer of 1 to 4.

  (7) The resin of component (A) has at least two types of repeating units: a (meth) acrylate repeating unit having a lactone structure and a (meth) acrylate repeating unit having an acid-decomposable group. The positive resist composition according to any one of (1) to (6).

  (8) The resin of component (A) is a repeating unit represented by the following general formula (A1), a repeating unit represented by the following general formula (A2), and a repeating unit represented by the following general formula (A3). The positive resist composition as described in any one of (1) to (7), wherein

In the general formulas (A1) to (A3),
Xa, Xb and Xc each independently represent a hydrogen atom or a methyl group.
R ₁ represents a monovalent organic group having a lactone structure.
R ₂ represents a monovalent organic group having a hydroxyl group or a cyano group.
R ₃ represents a group capable of leaving by the action of an acid.

  (9) A pattern forming method comprising a step of forming a resist film with the positive resist composition according to any one of (1) to (8), exposing and developing.

  (10) The pattern forming method according to (9), wherein exposure is performed through an immersion liquid.

  The preferred embodiments of the present invention will be further described below.

  (11) The positive resist composition as described in any one of (1) to (8) above, wherein the compound of component (B) has a triphenylsulfonium cation structure.

  (12) The positive resist composition as described in any one of (1) to (8) and (11) above, which further contains a surfactant.

  (13) The positive resist composition as described in any of (1) to (8), (11) and (12) above, which further contains a basic compound.

  (14) The (C) component resin has a weight average molecular weight of 3,000 to 15,000, and the (C) component resin has a dispersity of 1.2 to 3.0. The positive resist composition according to any one of (1) to (8) and (11) to (13).

  (15) The positive resist composition as described in any one of (1) to (8) and (11) to (14), wherein the resin as the component (C) does not have a fluorine atom or a silicon atom. object.

(16) In the general formula (C1), R ₁₂ , R ₁₃ and R ₁₄ are an alkyl group, a cycloalkyl group or an alkenyl group or a monovalent group to which these groups are bonded, and R _{12 to} R The positive resist composition as described in any one of (3) to (8) and (11) to (15), wherein the number of carbon atoms contained in ₁₄ is 6 to 20.

(17) The compound (B) is a compound that generates an aliphatic sulfonic acid having a fluorine atom or a benzenesulfonic acid having a fluorine atom upon irradiation with actinic rays or radiation. 8) and the positive resist composition according to any one of (11) to (16).

  (18) In any one of (1) to (8) and (11) to (17), the total solid concentration in the positive resist composition is 1.0 to 6.0% by mass. The positive resist composition as described.

  (19) The pattern forming method as described in (9) or (10), wherein the exposure is performed with an actinic ray or radiation having a wavelength of 1 nm to 200 nm.

  According to the present invention, it is possible to provide a positive resist composition with improved profile and pattern collapse and a pattern forming method using the same. Also provided are a positive resist composition suitable for immersion exposure and a pattern formation method using the same, in which the profile and pattern collapse do not change in immersion exposure and the followability to water is good. Can do.

Hereinafter, 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).

[1] (A) A resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkaline developer by the action of an acid. The resin used in the positive resist composition of the present invention may be monocyclic or A resin (acid-decomposable resin) having a polycyclic alicyclic hydrocarbon structure and increasing the solubility in an alkali developer by the action of an acid, and the main chain or side chain of the resin, or both the main chain and side chain And a resin having a group capable of decomposing under the action of an acid to generate an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”) (hereinafter referred to as “alicyclic hydrocarbon-based acid-decomposable resin” or “resin ( A) ").
Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
A preferable group as the acid-decomposable group is a group in which the hydrogen atom of these alkali-soluble groups is substituted with a group capable of leaving by the action of an acid.
Group capable of leaving by the action of an acid The (hereinafter, also referred to as "acid-eliminable group"), for _{example, -C (R 36) (R} 37) (R 38), - C (R 36) (R 37 ) (OR ₃₉ ), —C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ), and the like. In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring. R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  As resin (A), the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by the following general formula (pI)-general formula (pV), and the following general formula (II-AB) A resin having at least one repeating unit selected from the group of units is preferred.

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Further, either R ₁₉ or 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. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

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

  The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In general formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cycloalkyl group. At least two _{members out of} R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.
n represents 0 or 1.

In general formulas (pI) to (pV), the alkyl group represented by R _{12 to} R ₂₅ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, or n-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 6-30, and particularly preferably 7-25. These cycloalkyl groups may have a substituent.

  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 further have a substituent. Examples of further substituents include an alkyl group (1 to 4 carbon atoms), a halogen atom, a hydroxyl group, and an alkoxy group (1 to 4 carbon atoms). ), A carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms). 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 structures represented by the general formulas (pI) to (pV) in the resin can be used for protecting alkali-soluble groups.

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

In general formula (pA),
R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. A single bond is preferable.
Rpa represents any group of the general formulas (pI) to (pV).

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

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

In the general formula (II-AB), examples of the halogen atom represented by R ₁₁ ′ and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
Examples of the alkyl group in R ₁₁ ′ and R ₁₂ ′ include a linear or branched alkyl group having 1 to 10 carbon atoms.

The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in the resin, and in particular, a bridged alicyclic ring An atomic group for forming a bridged alicyclic structure forming a repeating unit of the formula hydrocarbon is preferred.
Examples of the skeleton of the alicyclic hydrocarbon formed include those similar to the cycloalkyl groups of R _{12 to} R _{25 in} the general formulas (pI) to (pV).
The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

  In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the group decomposed by the action of an acid has a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). It can be contained in at least one kind of repeating unit among the repeating unit having, the repeating unit represented by formula (II-AB), and the repeating unit of the copolymerization component described later.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) form an alicyclic structure in the general formula (II-AB). Or a substituent of the atomic group Z ′ for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a group having a lactone ring. As the group having a lactone ring, any group having a lactone ring can be used, but a group having a 5- to 7-membered ring lactone structure is preferred. A structure in which another ring structure is condensed to form a structure or a spiro structure is preferable. A group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16) is more preferable. 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), and (LC1-14). 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. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. 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.

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-13), R _{13 in the} above general formula (II-AB1) or (II-AB2) may be used. A group having a group represented by general formula (LC1-1) to (LC1-16) at least one of 'to R ₁₆ ' (for example, R _{5 of} -COOR ₅ is represented by formula (LC1-1) to ( And a repeating unit represented by the following general formula (AI).

In general formula (AI),
Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express. A linking group represented by a single bond or —Ab ₁ —CO ₂ — is preferable. Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.
V represents a group having a lactone structure represented by any one 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.
Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the polar group, a hydroxyl group and a cyano group are preferable. As the alicyclic hydrocarbon structure substituted with a preferable polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

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

The repeating unit having a partial structure represented by general formulas (VIIa) to (VIId) is at least one of R ₁₃ ′ to R ₁₆ ′ in general formula (II-AB1) or (II-AB2). Is a partial structure represented by the general formulas (VIIa) to (VIId) (for example, R _{5 of} —COOR ₅ represents a partial structure represented by the general formulas (VIIa) to (VIId)), Or the repeating unit represented by the following general formula (AIIa)-(AIId) can be mentioned.

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

  Specific examples of the repeating unit having a partial structure represented by the general formulas (VIIa) to (VIId) are given below, but the present invention is not limited thereto.

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

In the above general formula (VIII),
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

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

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By containing this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Any of the bonded repeating units is preferable, and the linking group may have a monocyclic or polycyclic hydrocarbon structure. Most preferred are acrylic acid and methacrylic acid.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may further have a repeating unit having 1 to 3 groups represented by the general formula (F1). This improves line edge roughness performance.

In general formula (F1),
R _{50 to} R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
Rxa represents a hydrogen atom or an organic group (preferably an acid-eliminable group, an alkyl group, a cycloalkyl group, an acyl group, or an alkoxycarbonyl group).

The alkyl group of R _{50 to} R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, etc., preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl group or a trifluoromethyl group. be able to. R _{50 to} R ₅₅ are preferably all fluorine atoms.

  Examples of the organic group represented by Rxa include an acid leaving group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. , 1-alkoxyethyl group is preferable.

  The repeating unit having a group represented by the general formula (F1) is preferably a repeating unit represented by the following general formula (F2).

In general formula (F2),
Rx represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rx may have include a hydroxyl group and a halogen atom.
Fa represents a single bond or a linear or branched alkylene group, preferably a single bond.
Fb represents a monocyclic or polycyclic hydrocarbon group.
Fc represents a single bond or a linear or branched alkylene group (preferably a single bond or a methylene group).
F ₁ represents a group represented by the general formula (F1).
p ₁ is an integer of 1 to 3.
The cyclic hydrocarbon group in Fb is preferably a cyclopentyl group, a cyclohexyl group, or a norbornyl group.

  Specific examples of the repeating unit having the structure of the general formula (F1) are shown.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. It can have various repeating structural units for the purpose of adjusting heat resistance, sensitivity and the like.

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

  As a result, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular, (1) solubility in coating solvent, (2) film-forming property (glass transition point), (3) alkali developability, (4 Fine adjustments such as () film slippage (selection of hydrophilicity / hydrophobicity, alkali-soluble group), (5) adhesion of unexposed part to substrate, (6) dry etching resistance, etc. are possible.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

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

  In alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

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

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 in all repeating structural units. -40 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 20 to 70 in all the repeating structural units. The mol% is preferable, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20-50 mol%.

  In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. ) To 99 p% with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon represented by (pV) and the repeating unit represented by the general formula (II-AB). The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

  When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The alicyclic hydrocarbon-based acid-decomposable resin includes a repeating unit represented by the following general formula (A1), a repeating unit represented by the following general formula (A2), and a repeating unit represented by the following general formula (A3). It is preferable to have.

In the general formulas (A1) to (A3),
Xa, Xb and Xc each independently represent a hydrogen atom or a methyl group.
R ₁ represents a monovalent organic group having a lactone structure.
R ₂ represents a monovalent organic group having a hydroxyl group or a cyano group.
R ₃ represents a group capable of leaving by the action of an acid.

The repeating unit represented by the general formula (A1) is preferably a repeating unit represented by the general formula (AI).
The ratio of the repeating unit represented by the general formula (A1) is preferably 25 to 50 mol% with respect to all the repeating units of the alicyclic hydrocarbon-based acid-decomposable resin.
The repeating unit represented by the general formula (A2) is represented by the general formula (AIIa) or (AIIb).
It is preferable that it is a repeating unit represented by these.
The ratio of the repeating unit represented by the general formula (A2) is preferably 5 to 30 mol% with respect to all the repeating units of the alicyclic hydrocarbon-based acid-decomposable resin.
The repeating unit represented by the general formula (A3) is preferably a repeating unit represented by the general formula (pA).
The ratio of the repeating unit represented by the general formula (A3) is preferably 25 to 50 mol% with respect to all the repeating units of the alicyclic hydrocarbon-based acid-decomposable resin.

As the alicyclic hydrocarbon-based acid-decomposable resin for use in the present invention, all of the repeating units are preferably composed of repeating units of (meth) acrylate. In this case, any of a resin in which all of the repeating units are repeating units of methacrylate, a resin in which all of the repeating units are repeating units of acrylate, and a resin in which the repeating units are repeating units of a methacrylate / acrylate mixture may be used. However, it is preferable that the repeating unit by acrylate is 50 mol% or less of all repeating units. More preferably, the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 20 to 50 mol%, the repeating unit having the lactone structure is 20 to 50 mol%, the above It is a ternary copolymer containing 5 to 30 mol% of repeating units having an alicyclic hydrocarbon structure substituted with a polar group, or a quaternary copolymer containing 0 to 20 mol% of other repeating units.
Particularly preferable alicyclic hydrocarbon-based acid-decomposable resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-5), and the following general formula ( 20 to 50 mol% of repeating units having a lactone structure represented by ARL-1) to (ARL-6), substituted with polar groups represented by the following general formulas (ARH-1) to (ARH-3) A terpolymer having 5 to 30 mol% of repeating units having an alicyclic hydrocarbon structure, or a repeating unit having a structure represented by a carboxyl group or general formula (F1) or an alicyclic hydrocarbon structure. And a quaternary copolymer containing 5 to 20 mol% of repeating units not exhibiting acid decomposability.
(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, and Rxa ₁ and Rxb ₁ each independently represents a methyl group or an ethyl group.)

  The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention preferably has a weight average molecular weight in the range of 1500 to 100,000, more preferably in the range of 2000 to 70000, and particularly preferably in the range of 3000 to 50000. The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention preferably has a dispersity (Mw / Mn) of 1.0 to 3.0, more preferably 1.2 to 2.5, and even more. Preferably it is 1.2-1.6.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has no fluorine atom or silicon atom from the viewpoint of compatibility with the resin of component (C).

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

  In the present invention, the addition amount of the resin (A) in the positive resist composition is 50 to 99.7% by mass, preferably 70 to 99.5% by mass, based on the total solid content. In addition to the resin in the present invention, other resins can be used as necessary. In the composition of the present invention, the preferred range of use of other resins can be mixed at a ratio of 70 parts by mass or less, particularly preferably 50 parts by mass or less, per 100 parts by mass of the resin (A) in the present invention.

[2] (B) Compound that generates acid upon irradiation with actinic ray or radiation The positive resist 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”). ).
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, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

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

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

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

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

In general formula,
Rc ₁ represents an organic group.
Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality of these are a single bond, —O—, —CO ₂ —, —S—. , —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like. Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group. Preferred examples of the organic group for Rc ₃ , Rc ₄ , and Rc ₅ include the same organic groups as those for Rb ₁ , and particularly preferred is a perfluoroalkyl group having 1 to 4 carbon atoms.
Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group.
The organic group represented by Rc ₁ or Rc _{3 to} Rc ₅ is particularly preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. Further, when Rc ₃ and Rc ₄ are combined to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved.

In formula (ZI), the carbon number of the organic group as R _201, R ₂₀₂ and R ₂₀₃ is generally from 1 to 30, preferably 1 to 20.
It is also possible to form the two members ring structure of the R ₂₀₁ to R _203, an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

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

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

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are straight chain, branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and straight chain, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and particularly preferred. Is an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is in the general formula (ZI), R ₂₀₁ ~R ₂₀₃ are each independently a compound when it 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, branched, cyclic 2-oxoalkyl group, an alkoxycarbonylmethyl group, Particularly preferred is a linear or branched 2-oxoalkyl group.

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

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ⁻ represents a non-nucleophilic anion and is the same as the non-nucleophilic anion of X ^{− in} formula (I).

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

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group having 1 to 10 carbon atoms, e.g., methyl group, ethyl group, propyl group Butyl group, pentyl group and the like.
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group.
R ₂₀₄ to R ₂₀₇ may have a substituent. The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g. having 6 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms ), Halogen atoms, hydroxyl groups, phenylthio groups, and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (I).

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, preferred compounds are those represented by the following general formula (ZIV), (ZV), or (ZVI).

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₆ represents an alkyl group, a cycloalkyl group or an aryl group.
R ₂₀₇ and R ₂₀₈ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or an electron-withdrawing group. R ₂₀₇ is preferably an aryl group. R ₂₀₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents an alkylene group, an alkenylene group or an arylene group.

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

  The compound that generates an acid upon irradiation with actinic rays or radiation is more preferably a compound having a triphenylsulfonium cation structure.

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

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

[3] (C) Resin Having Repeating Unit Represented by General Formula (C) The positive resist composition of the present invention contains a resin having a repeating unit represented by the following general formula (C).

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.

In the general formula (C), the alkyl group of X ₁ , X ₂ and X ₃ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, or n-propyl. Group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, isopentyl group, neopentyl group, t-pentyl group and the like.

  The divalent linking group of L is, for example, a single group selected from the group consisting of an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. Are preferred, or a divalent linking group in which two or more of these are combined.

Examples of the acid-decomposable group for Rp ₁ include groups in which an alkali-soluble group such as a carboxyl group and a phenolic hydroxyl group, preferably a hydrogen atom of the carboxyl group is protected with a group capable of leaving by the action of an acid. Can do.
Examples of the group capable of leaving by the action of an acid include —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), —C (R ₀₁ ) ( R ₀₂ ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The alkyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an alkyl group having 1 to 8 carbon atoms, such as methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl. Group, octyl group and the like.
The cycloalkyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ may be monocyclic or polycyclic. As the monocyclic type, a cycloalkyl group having 3 to 8 carbon atoms is preferable, for example, a cyclopropyl group,
A cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, etc. can be mentioned. As the polycyclic type, a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetracyclododecyl group. Group, androstanyl group and the like. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
The aryl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The aralkyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.
The alkenyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.
R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ may have a substituent. Examples of the substituent that R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ may have include, for example, an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, a urethane group, a hydroxyl group, Examples thereof include a carboxyl group, a halogen atom, an alkoxy group, a thioether group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a cyano group, and a nitro group.

  The general formula (C) is preferably represented by the following general formula (C1).

In general formula (C1),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring.

In formula (C1), X _1, X ₂ and X ₃ are in the the general formula (C), and the X _1, X ₂ and X ₃ synonymous.
Examples of the alkyl group, cycloalkyl group, alkenyl group, and aryl group of R ₁₂ , R _13, and R ₁₄ include an alkyl group of R _{36 to} R ₃₈ , a cycloalkyl group in the group leaving by the action of the acid, The same thing as an alkenyl group and an aryl group can be mentioned.

In the repeating unit represented by the general formula (C1), R ₁₂ , R _13, and R ₁₄ are each independently an alkyl group or an alkenyl group, and at least one of R ₁₂ , R _13, and R ₁₄ Is more preferably an alkyl group.
Repeating unit represented by formula _{(C1), R 12, R} 13 and R ₁₄ is an alkyl group, a monovalent group a cycloalkyl group or alkenyl group, or these groups are bonded, R ₁₂ ~ The number of carbon atoms contained in R ₁₄ is preferably 6-20.

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

In the above example,
Rx represents a hydrogen atom or a methyl group.
Rxa, Rxb and Rxc each independently represents an alkyl group having 1 to 4 carbon atoms.
Rxx represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

  The resin of component (C) may have other repeating units in addition to the repeating unit represented by the general formula (C).

  Examples of the other repeating unit that the resin of component (C) may have include a repeating unit represented by the following general formula (C2).

In general formula (C2),
X ₄ , X ₅ and X ₆ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L ₁ represents a single bond or a divalent linking group.
Rp ₂ represents a non-acid-decomposable group.

X ₄ , X ₅ and X ₆ in the general formula (C2) are the same as X ₁ , X ₂ and X _{3 in} the general formula (C).
Examples of the divalent linking group of L ₂ include the same divalent linking groups as those of L in the general formula (C). The divalent linking group of L ₂ is preferably an alkylene group, an ester group or an ether group.
Examples of the non-acid-decomposable group for Rp ₂ include a linear or branched alkyl group (preferably having 2 to 20 carbon atoms), a cycloalkyl group (preferably having an alkali-soluble group that is not decomposed by the action of an acid). May include an aryl group (preferably 6 to 15 carbon atoms), an alkenyl group (preferably 2 to 10 carbon atoms), and the like. A branched alkyl group, a cycloalkyl group, and an alkenyl group are preferable.

  As another repeating unit that the resin of component (C) may have, the repeating unit represented by the general formula (VIII) in the resin of component (A) can be further exemplified.

  The resin of component (C) preferably has 80 to 100 mol% of the repeating unit represented by the general formula (C1) and the repeating unit represented by the general formula (C2) in all repeating units, It is more preferable to have 100 mol%.

In the general formulas (C1) and (C2),
X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring.
L ₁ represents a single bond or a divalent linking group.
Rp ₂ represents a non-acid-decomposable group.
m and n respectively represent the molar ratio of the repeating units, and m = 10 to 100, n = 0 to 90, and m + n = 100.

  The resin of the component (C) is a repeating unit selected from the following general formulas (CI) to (C-IV) in all the repeating units (provided that the repeating unit represented by the general formula (CI)) The repeating units represented by formula (C-II) are preferably used in combination) in an amount of 80 mol% to 100 mol%.

In the general formulas (C-I) to (C-IV),
R ₁ represents a hydrogen atom or a methyl group.
When there are a plurality of R _{2 s} , each R ₂ independently represents a hydrocarbon group having at least two partial structures of —CH ₃ .
P ₁ represents a single bond, an alkylene group or an ether group, or a linking group in which two or more of them are bonded.
P ₂ represents a linking group selected from —O—, —NR— (R represents a hydrogen atom or an alkyl group) and —NHSO ₂ —.
x1, x2, y, and z represent mol% in all repeating units, x1 represents 0 to 50, x2 represents 0 to 50, y represents 0 to 100, and z represents 0 to 100. However, 80 ≦ x1 + x2 + y + z ≦ 100 is satisfied.
n represents an integer of 1 to 4.

In the general formulas (CI) to (C-IV), the hydrocarbon group having at least two —CH ₃ partial structures of R ₂ has, for example, at least two —CH ₃ partial structures. An alkyl group, an alkyloxy group, an alkyl-substituted cycloalkyl group, an alkyl-substituted alkenyl group, an alkyl-substituted aryl group, an alkyl-substituted aralkyl group, etc., and an alkyl group and an alkyl-substituted group having at least two —CH ₃ partial structures A cycloalkyl group is preferred.

In the general formulas (CI) to (C-IV), the hydrocarbon group having at least two —CH ₃ partial structures of R ₂ has, for example, at least two —CH ₃ partial structures. alkyl group, at least two having alkyl group partial structures of -CH _3, at least one alkyl group having at least two at least two alkyl or partial structure -CH ₃ having one partial structure -CH ₃ in substituted cycloalkyl group, at least two alkyl groups or at least one alkenyl group substituted with an alkyl group having at least two partial structures of -CH ₃ having one partial structure -CH _3, -CH ₃ at least two alkyl groups or at least one alkyl group having at least two partial structures of -CH ₃ having one of the partial structure Conversion aryl groups include at least two alkyl groups or at least one aralkyl group substituted with an alkyl group having at least two partial structures of -CH ₃ having one partial structure -CH _3, -CH ₃ At least two alkyl groups with a moiety of at least two having alkyl group partial structures of -CH _3, at least two alkyl or partial structure -CH ₃ having one partial structure -CH ₃ Preferred are cycloalkyl groups substituted with at least one alkyl group having at least two. The alkyl group having at least two partial structures of —CH ₃ may be substituted with a cycloalkyl group.

The alkyl group having at least two —CH ₃ partial structures in R ₂ is preferably a branched alkyl group having 3 to 20 carbon atoms. Specific examples of preferable alkyl groups include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5- Examples thereof include a dimethyl-3-heptyl group and 2,3,5,7-tetramethyl-4-heptyl group. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, a 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group is there.
The alkyl group having one —CH ₃ partial structure in R ₂ is preferably a linear alkyl group having 1 to 20 carbon atoms. Specific examples of preferred alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and nonyl groups.

Examples of the alkyloxy group having at least two —CH ₃ partial structures in R ₂ include groups in which an ether group is bonded to an alkyl group having at least two —CH ₃ partial structures.

The cycloalkyl group in R ₂ may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. 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. More preferably, they are a norbornyl group, a cyclopentyl group, and a cyclohexyl group.
The alkenyl group in R ₂ is preferably a linear or branched alkenyl group having 1 to 20 carbon atoms, and more preferably a branched alkenyl group.
The aryl group in R ₂ is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group and a naphthyl group, and a phenyl group is preferable.
The aralkyl group in R ₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

Specific examples of the hydrocarbon group having at least two —CH ₃ partial structures in the general formulas (CI) to (C-III) and R ₂ include isopropyl group, isobutyl group, t- Butyl group, 3-pentyl group, 2-methyl-3-butyl group, 3-hexyl group, 2,3-dimethyl-2-butyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2 , 3,5,7-tetramethyl-4-heptyl group, 3,5-dimethylcyclohexyl group, 4-isopropylcyclohexyl group, 4-tbutylcyclohexyl group, isobornyl group and the like. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2,3-dimethyl-2-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5 , 7-tetramethyl-4-heptyl group, 3,5-dimethylcyclohexyl group, 4-isopropylcyclohexyl group, 4-tbutylcyclohexyl group and isobornyl group.
Specific examples of the hydrocarbon group having at least two —CH ₃ partial structures in the general formula (C-IV) and R ₂ include an isobutyl group, a t-butyl group, a 3-pentyl group, 2 , 3-dimethylbutyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, Isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4- Examples include heptyl group, 3,5-dimethylcyclohexyl group, 4-isopropylcyclohexyl group, 4-tbutylcyclohexyl group and the like. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, a 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group, A 2,6-dimethylheptyl group, a 3,5-dimethylcyclohexyl group, a 4-isopropylcyclohexyl group, and a 4-tbutylcyclohexyl group.

In a resin having a repeating unit selected from the general formulas (CI) to (C-IV): 8
0 ≦ x1 + x2 + y + z ≦ 100, preferably 85 ≦ x1 + x2 + y + z ≦ 100, more preferably 90 ≦ x1 + x2 + y + z ≦ 100.

In the resin having a repeating unit selected from the general formulas (CI) to (C-IV), at least one of the repeating units selected from the general formulas (CI) to (C-IV) is acid-decomposable. It preferably has a group.
Examples of the acid-decomposable group in the general formulas (CI) to (C-IV) include the same groups as the acid-decomposable group for Rp _{1 in} the general formula (C).

  Preferred specific examples of the repeating units represented by the general formulas (CI) to (C-II) are shown below. Note that the present invention is not limited to this.

  Specific preferred examples of the repeating unit represented by formula (C-III) are shown below. Note that the present invention is not limited to this.

In the general formula (C-IV), when P ₂ is an oxygen atom, the carbon atom directly connected to the oxygen atom is preferably secondary or tertiary, and when it is tertiary, the general formula ( It has the same structure as the repeating unit represented by C1).

  Preferred specific examples of the repeating unit represented by the general formula (C-IV) other than the repeating unit represented by the general formula (C1) are given below. Note that the present invention is not limited to this. In specific examples, Rxy represents a hydrogen atom or a methyl group.

The resin of component (C) preferably has no silicon atom or fluorine atom.
The resin of component (C) preferably has no elements other than carbon atoms, hydrogen atoms, oxygen atoms, nitrogen atoms and sulfur atoms.

  The resin of component (C) preferably has 5 to 100 mol%, more preferably 10 to 100 mol% of repeating units having an acid-decomposable group.

  The resin of component (C) is preferably in the range of weight average molecular weight 1500-100000, more preferably 2000-70000, even more preferably 3000-50000, particularly preferably 3000-15000. is there. The resin of component (C) preferably has a dispersity (Mw / Mn) of 1.0 to 3.0, more preferably 1.2 to 2.5, and even more preferably 1.2 to 2. .0.

  The resin of component (C) can be synthesized in the same manner as the resin of component (A). A chain transfer agent can also be used as needed.

  The content of the resin of component (C) is 0.1 to 20% by mass based on the solid content of the positive resist composition (total solid content constituting the resist film), and 0.1 to 10% by mass. It is preferable that Furthermore, it is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and particularly preferably 0.5 to 2% by mass.

[4] (D) Organic solvent Examples of the solvent that can be used in preparing the positive resist composition by dissolving the above components include alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, Examples include alkyl lactate, alkyl alkoxypropionate, cyclic lactones having 4 to 10 carbon atoms, monoketone compounds having 4 to 10 carbon atoms which may contain a ring, alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate and the like. it can.

Examples of the alkylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl Preferred examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.
Preferred examples of the alkylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferred examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate and butyl lactate.
Preferable examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate.

  Examples of the cyclic lactone having 4 to 10 carbon atoms include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ- Caprolactone, γ-octanoic lactone, and α-hydroxy-γ-butyrolactone are preferred.

Examples of the monoketone compound having 4 to 10 carbon atoms which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4- Methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2 -Hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4 -Heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5- Xen-2-one, 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopenta Non, cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcyclo Preferred are heptanone and 3-methylcycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.
Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.

As a solvent which can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid -2- (2-ethoxyethoxy) ethyl and propylene carbonate are mentioned.
In the present invention, the above solvents may be used alone or in combination of two or more.

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.
Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.
Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone is most preferred.
The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.

  In the present invention, the total solid concentration in the positive resist composition is preferably 1.0 to 6.0% by mass.

[5] (E) Basic compound The positive resist composition of the present invention preferably contains (E) a basic compound in order to reduce a 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) to (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. Here, R ²⁰¹ and R ²⁰² may combine with each other to form a ring.
The alkyl group may be unsubstituted or may have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, Or a C1-C20 cyanoalkyl group is preferable.
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.
The alkyl groups in these general formulas (A) to (E) are more preferably unsubstituted.

  Examples of basic compounds include substituted or unsubstituted primary, secondary, and tertiary aliphatic amines, aromatic amines, heterocyclic amines, amide derivatives, imide derivatives, and cyano groups. Examples thereof include nitrogen-containing compounds. Of these, aliphatic amines, aromatic amines, and heterocyclic amines are preferable. Preferred substituents that may be present are an amino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a cyano group, an ester group, and a lactone group.

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferable compounds include compounds having an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, a hydroxyl group and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. 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. ] Undec-7-ene. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety 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 aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  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 resist 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.

[6] (F) Surfactant The positive resist composition of the present invention preferably further contains (F) a surfactant, and is a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, It is more preferable to contain any one of a silicon-based surfactant, a surfactant having both a fluorine atom and a silicon atom, or two or more thereof.

When the positive resist composition of the present invention contains the surfactant (F), a resist having good sensitivity and resolution and less adhesion and development defects when using an exposure light source of 250 nm or less, particularly 220 nm or less. A pattern can be given.
Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189 , F113, F110, F177, F120, R08 (manufactured by Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (Manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toa Gosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M , EF135M, EF351, 352, EF801, EF802, EF 01 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208G, 218G, 230G, 204D, 208D, 212D, 218, 222D (manufactured by Neos) Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₃ F ₇ group and (poly (oxy) And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

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

  These surfactants may be used alone or in several combinations.

  (F) The usage-amount of surfactant becomes like this. Preferably it is 0.01-10 mass% with respect to positive resist composition whole quantity (except a solvent), More preferably, it is 0.1-5 mass%.

[7] (G) Onium carboxylate The positive resist composition in the present invention may contain an onium carboxylate. Examples of carboxylic acid onium salts include carboxylic acid sulfonium salts, carboxylic acid iodonium salts,
Examples include carboxylic acid ammonium salts. In particular, as the carboxylic acid onium salt, an iodonium salt and a sulfonium salt are preferable. Furthermore, it is preferable that the carboxylate residue of the carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. As a particularly preferable anion moiety, a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms is preferable. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

  Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , 2-bistrifluoromethylpropionic acid anion and the like.

  These carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

  The content of the carboxylic acid onium salt in the composition is suitably from 0.1 to 20% by weight, preferably from 0.5 to 10% by weight, more preferably from 1 to 7% by weight, based on the total solid content of the composition. %.

Other Additives The positive resist composition of the present invention further promotes solubility in dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors and developers as necessary. A compound (for example, a phenol compound having a molecular weight of 1000 or less, an alicyclic compound having a carboxyl group, or an aliphatic compound) and the like can be contained.

Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

[Physical properties of resist composition]
The positive resist composition of the present invention is preferably used at a film thickness of 30 to 250 nm, more preferably at a film thickness of 30 to 200 nm, from the viewpoint of improving resolution. Such a film thickness can be obtained by setting the solid content concentration in the positive resist composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The total solid concentration in the positive resist composition is generally 1 to 10% by mass, more preferably 1 to 8% by mass, and still more preferably 1.0 to 7.0% by mass.

[Pattern formation method]
The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows. 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 still more preferably 0.03 microns or less.

For example, a positive resist composition is coated on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit element by an appropriate coating method such as a spinner or a coater, and dried to form a resist film. Form.
The positive resist composition of the present invention is preferably used at a film thickness of 30 to 500 nm, more preferably at a film thickness of 30 to 250 nm, more preferably from the viewpoint of improving resolution. It is preferably used at 30 to 200 nm.
The resist film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.

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.

  In the present invention, the exposure is preferably performed with actinic rays or radiation having a wavelength of 1 nm to 200 nm.

In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
The development process or the rinsing process may be performed by forming a paddle or may be performed by a paddleless process. In the case of immersion exposure, a rinsing step may be performed before and after exposure.
Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

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

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist. In the case of an ArF excimer laser (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.
Further, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

  When water is used as the immersion liquid, the surface tension of the water is decreased and the surface activity is increased, so that the resist layer on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained. On the other hand, when an opaque substance or impurities whose refractive index is significantly different from that of water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. Therefore, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.

The electrical resistance of water is desirably 18.3 MQcm or more, the TOC (organic substance concentration) is desirably 20 ppb or less, and deaeration treatment is desirably performed.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive for increasing the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

Since the resist film is not directly brought into contact with the immersion liquid between the resist film of the positive resist composition of the present invention and the immersion liquid, it is also referred to as an “immersion liquid hardly soluble film” (hereinafter referred to as “top coat”). ) May be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers. From the viewpoint of contaminating the optical lens when impurities are eluted from the top coat into the immersion liquid, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.
The resolution is improved when there is no difference in refractive index between the top coat and the immersion liquid. In the case of using water as the immersion liquid in an ArF excimer laser (wavelength: 193 nm), the top coat for ArF immersion exposure is preferably close to the refractive index of the immersion liquid. From the viewpoint of making the refractive index close to the immersion liquid, it is preferable to have fluorine atoms in the topcoat. A thin film is more preferable from the viewpoint of transparency and refractive index.

  It is preferred that the top coat is not mixed with the resist and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, the topcoat solvent is preferably a resist solvent hardly soluble and water-insoluble medium. Furthermore, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

  Since the resin (C) contained in the resist is unevenly distributed on the surface, the positive resist composition of the present invention can improve the contact angle (particularly the receding contact angle) of the film surface. When the resist film is formed, the receding contact angle of water with respect to the resist film is preferably 60 ° or more, more preferably 65 ° or more, and still more preferably 70 ° or more. The receding contact angle of the film when only the resin (C) is dissolved and applied is preferably 70 ° to 110 °. It is preferable to adjust the receding contact angle of the resist film to 60 ° to 80 ° by adjusting the amount of the resin (C) added. Here, the receding contact angle is at normal temperature and pressure. The receding contact angle is the receding contact angle when the droplet starts to drop when the resist film is tilted.

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

Synthesis Example 1 (Synthesis of Resin (C-1))
Ethyl methacrylate and t-butyl methacrylate were charged at a ratio (molar ratio) of 50/50 and dissolved in cyclohexanone to prepare 450 g of a solution having a solid content concentration of 22% by mass. To this solution, 5 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added, and this was added dropwise to 50 mL of cyclohexanone heated to 80 ° C. over 2 hours in a nitrogen atmosphere. After completion of dropping, the mixture was stirred for 2 hours to obtain a reaction solution. The reaction solution was cooled to room temperature, crystallized in 10 times the amount of methanol, and the precipitated white powder was collected by filtration to recover the target resin (C-1).
^The polymer composition ratio (molar ratio) determined from ¹ HNMR was 50/50. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 10000, and dispersion degree was 2.2.

  Resins (C-2) to (C-20) as component (C) were synthesized in the same manner as in Synthesis Example 1.

  Hereinafter, the structures of the resins (C-1) to (C-20) are shown.

  Tables 1 and 2 below show the compositions (molar ratio, corresponding to each repeating unit in order from the left), Mw (weight average molecular weight), and Mw / Mn (dispersion degree) of resins (C-1) to (C-20). Show.

  Hereinafter, the structures of the resins (1) to (25) of the component (A) used in the examples are shown.

  Tables 3 to 4 below show the compositions (molar ratio, corresponding to each repeating unit in order from the left), Mw (weight average molecular weight), and Mw / Mn (dispersion degree) of resins (1) to (25).

Examples 1-15 and Comparative Examples 1-2
<Resist preparation>
The components shown in Table 5 below were dissolved in a solvent, and a solution with a solid content concentration of 6% by mass was prepared for each, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 5.

[Image performance test]
(Exposure condition (1))
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 a 78 nm antireflection film. A positive resist solution prepared thereon was applied and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, σo / σi = 0.85 / 0.55, manufactured by ASML). Thereafter, heating was performed at 120 ° 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.

(Exposure condition (2))
This condition is to form a resist pattern by an immersion exposure method using pure water.
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 a 78 nm antireflection film. A positive resist solution prepared thereon was applied and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. The obtained wafer 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. Thereafter, heating was performed at 120 ° 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.

[Profile]
The profile of the obtained pattern was observed and evaluated with a scanning electron microscope (S-9260, manufactured by Hitachi, Ltd.).

[Pattern collapse]
When an exposure amount that reproduces a 90 nm line and space 1: 1 mask pattern is an optimum exposure amount, and a dense pattern of line and space 1: 1 and an isolated pattern of line and space 1:10 are exposed at the optimum exposure amount Therefore, the line width that resolves the pattern without falling down in a fine mask size was defined as the limit pattern falling line width (nm). A smaller value indicates that a finer pattern is resolved without falling, and that pattern falling is less likely to occur.

[Water followability]
The prepared positive resist solution was applied onto a silicon wafer and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. Next, as shown in FIG. 1, pure water 2 was filled between the obtained positive resist solution-coated wafer 1 and the quartz glass substrate 3.
In this state, the quartz glass substrate 3 was moved (scanned) parallel to the surface of the wafer 1 coated with the positive resist solution, and the state of the pure water 2 following the surface was visually observed. Gradually increase the scanning speed of the quartz glass substrate 3 and obtain the limit scanning speed (nm / second) at which the pure water 2 cannot follow the scanning speed of the quartz glass substrate 3 and water droplets start to remain on the receding side. Follow-up was evaluated. As this limit scan speed is larger, water can follow a higher scan speed, and the water followability on the resist film is better.

  The symbols in Table 5 are as follows.

N-1: N, N-dibutylaniline N-2: N, N-dihexylaniline N-3: 2,6-diisopropylaniline N-4: tri-n-octylamine N-5: N, N-dihydroxyethyl Aniline N-6: 2,4,5-triphenylimidazole

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: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF656 (manufactured by OMNOVA, fluorine-based)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)

SL-1: Cyclohexanone SL-2: Propylene glycol monomethyl ether acetate SL-3: Ethyl lactate SL-4: Propylene glycol monomethyl ether SL-5: γ-butyrolactone SL-6: Propylene carbonate

  From the results of Table 5, the positive resist composition of the present invention is excellent in profile and pattern collapse in normal exposure and liquid immersion exposure, and in water immersion in liquid immersion exposure. I understand.

Examples 16 to 28 and Comparative Examples 3 to 4
<Resist preparation>
The components shown in Table 6 below were dissolved in a solvent, and a solution with a solid content concentration of 6% by mass was prepared for each, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 6.

[Image performance test]
(Exposure condition (1))
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 a 78 nm antireflection film. A positive resist solution prepared thereon was applied and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, σo / σi = 0.85 / 0.55, manufactured by ASML). Thereafter, heating was performed at 120 ° 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.

(Exposure condition (2))
This condition is to form a resist pattern by an immersion exposure method using pure water.
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 a 78 nm antireflection film. A positive resist solution prepared thereon was applied and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. The obtained wafer 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. Thereafter, heating was performed at 120 ° 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.

[Profile]
The profile of the obtained pattern was measured with a scanning electron microscope (S-92 manufactured by Hitachi, Ltd.).
60) and evaluated.

[Pattern collapse]
When an exposure amount that reproduces a 90 nm line and space 1: 1 mask pattern is an optimum exposure amount, and a dense pattern of line and space 1: 1 and an isolated pattern of line and space 1:10 are exposed at the optimum exposure amount Therefore, the line width that resolves the pattern without falling down in a fine mask size was defined as the limit pattern falling line width (nm). A smaller value indicates that a finer pattern is resolved without falling, and that pattern falling is less likely to occur.

[Water followability]
The prepared positive resist solution was applied onto a silicon wafer and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. Next, as shown in FIG. 1, pure water 2 was filled between the obtained positive resist solution-coated wafer 1 and the quartz glass substrate 3.
In this state, the quartz glass substrate 3 was moved (scanned) parallel to the surface of the wafer 1 coated with the positive resist solution, and the state of the pure water 2 following the surface was visually observed. Gradually increase the scanning speed of the quartz glass substrate 3 and obtain the limit scanning speed (nm / second) at which the pure water 2 cannot follow the scanning speed of the quartz glass substrate 3 and water droplets start to remain on the receding side. Follow-up was evaluated. As this limit scan speed is larger, water can follow a higher scan speed, and the water followability on the resist film is better.

[Sensitivity evaluation]
An antireflection film (ARC25, manufactured by Brewer Science Co., Ltd.) was uniformly applied on the silicon substrate by a spin coater at 600 angstroms, and dried at 190 ° C. for 240 seconds. Next, each positive resist composition was applied by a spin coater, and the wafer was heated and dried at 115 ° C. for 60 seconds to form a 0.25 μm resist film. With respect to this resist film, a 193 nm laser exposure / dissolution behavior analyzer IMES-5500 (manufactured by RISOTEC Japan) was used, and the sensitivity by 193 nm exposure was evaluated using water as the immersion liquid.
The sensitivity here means that the wafer after exposure is heated and dried at 120 ° C. for 90 seconds, then developed using a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 30 seconds, and pure water for 30 seconds. When the film thickness is measured after rinsing and drying, it indicates the minimum exposure amount at which the film thickness becomes zero.

  The symbols in Table 6 are as follows.

N-1: N, N-dibutylaniline N-2: N, N-dihexylaniline N-3: 2,6-diisopropylaniline N-4: tri-n-octylamine N-5: N, N-dihydroxyethyl Aniline N-6: 2,4,5-triphenylimidazole

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: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF656 (manufactured by OMNOVA, fluorine-based)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)

SL-1: Cyclohexanone SL-2: Propylene glycol monomethyl ether acetate SL-3: Ethyl lactate SL-4: Propylene glycol monomethyl ether SL-5: γ-butyrolactone SL-6: Propylene carbonate

  The additive (H-1) used in Comparative Example 3 is a compound used for comparison with the resin of component (C).

  From the results of Table 6, the positive resist composition of the present invention is excellent in profile and pattern collapse in normal exposure and liquid immersion exposure, and further in water followability and sensitivity in liquid immersion exposure. I understand that.

It is the schematic which shows the state which is evaluating the water followability to a quartz plate.

Explanation of symbols

1 Wafer coated with positive resist solution 2 Pure water 3 Quartz glass substrate

Claims (12)

(A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) A resin having a repeating unit represented by the following general formula (C) (excluding a resin in which an alicyclic hydrocarbon group having a ketone group is substituted on the side chain and the following resin A) and (D) a solvent And a content of the resin as the component (C) is 0.1 to 5% by mass based on the solid content of the positive resist composition.

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.
Resin A is a resin obtained by polymerization of monomers shown below.

2. The positive resist composition according to claim 1 , wherein the general formula (C) is the following general formula (C1).

In general formula (C1),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring. In the general formula (C1), R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group or an alkenyl group, and at least one of R ₁₂ , R ₁₃ and R ₁₄ is an alkyl group The positive resist composition according to claim 2 , wherein The resin of the component (C) has 80 to 100 mol% of the repeating unit represented by the following general formula (C1) and the repeating unit represented by the following general formula (C2) in all repeating units. The positive resist composition according to any one of claims 1 to 3 .

In the general formulas (C1) and (C2),
X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
R ₁₂ , R ₁₃ and R ₁₄ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or a monovalent group to which these groups are bonded. However, at least one of R ₁₂ , R ₁₃ and R ₁₄ represents an alkyl group. Two of R ₁₂ , R ₁₃ and R ₁₄ may combine to form a ring.
L ₁ represents a single bond or a divalent linking group.
Rp ₂ represents a non-acid-decomposable group.
m and n respectively represent the molar ratio of the repeating units, and m = 10 to 100, n = 0 to 90, and m + n = 100. Rp ₂ 5 represents a non-acid-decomposable group selected from linear or branched alkyl groups, cycloalkyl groups, aryl groups, and alkenyl groups. The positive resist composition according to claim 1, wherein the resin as the component (C) does not have a silicon atom or a fluorine atom. The resin of component (A) has at least two types of repeating units, a (meth) acrylate repeating unit having a lactone structure and a (meth) acrylate repeating unit having an acid-decomposable group. the positive resist composition according to any one of 1-6. The resin of component (A) has a repeating unit represented by the following general formula (A1), a repeating unit represented by the following general formula (A2), and a repeating unit represented by the following general formula (A3). The positive resist composition according to any one of claims 1 to 7 , wherein

In the general formulas (A1) to (A3),
Xa, Xb and Xc each independently represent a hydrogen atom or a methyl group.
R ₁ represents a monovalent organic group having a lactone structure.
R ₂ represents a monovalent organic group having a hydroxyl group or a cyano group.
R ₃ represents a group capable of leaving by the action of an acid. A resist film formed from the positive resist composition according to claim 1. A pattern forming method comprising the steps of exposing and developing the resist film according to claim 9 . The pattern forming method according to claim 10 , wherein exposure is performed through an immersion liquid. (A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a resin having a repeating unit represented by the following general formula (C) (excluding the following resin A) and
(D) Solvent
And a resist film is formed with a positive resist composition in which the content of the resin of component (C) is 0.1 to 5% by mass based on the solid content of the positive resist composition, A pattern forming method comprising a step of exposing and developing through an immersion liquid.

In general formula (C),
X ₁ , X ₂ and X ₃ each independently represent a hydrogen atom, an alkyl group or a halogen atom.
L represents a single bond or a divalent linking group.
Rp ₁ represents an acid-decomposable group.
Resin A is a resin obtained by polymerization of monomers shown below.

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