JP5002349B2 - Resist composition and pattern forming method using resist composition - Google Patents

Description

  The present invention relates to a resist composition whose properties change upon reaction by irradiation with actinic rays or radiation, and a pattern forming method using the resist composition. More specifically, a resist composition used in semiconductor manufacturing processes such as IC, circuit boards such as liquid crystals and thermal heads, and other photofabrication processes, lithographic printing plates, and acid curable compositions, and the resist composition The present invention relates to a pattern forming method using an object.

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

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 resist film has been known.
As for the "effect of immersion", the lambda ₀ is the wavelength of exposure light in air, the refractive index of the immersion liquid to air is n, the θ and convergence half of the light beam and when the NA ₀ = sin [theta, and immersion In this case, the resolution and the 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 shown in Non-Patent Document 1 (SPIE Proc 4688, 11 (2002)) and Patent Document 3 (
International publication WO2004-077158 pamphlet). 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.

When a chemically amplified resist is applied to immersion exposure, the resist film comes into contact with the immersion liquid at the time of exposure, so that the resist film is altered and components that adversely affect the immersion liquid are leached from the resist film. It 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. .
For example, when a chemically amplified resist is applied to immersion exposure, further improvements in pattern shape and line edge roughness are required, and suppression of acid elution from the resist film to the immersion liquid is required. Yes.

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

  The object of the present invention is that in immersion exposure, the receding contact angle with respect to the immersion liquid is large, the pattern shape is good, the line edge roughness is improved, and the elution of acid into the immersion liquid is suppressed. It is to provide a resist composition and a pattern forming method using the resist composition.

一般式（Ｆ３ａ）に於いて、
Ｒ _６２ａ 及びＲ _６３ａ は、各々独立に、少なくとも１つの水素原子がフッ素原子で置換されたアルキル基を表す。Ｒ _６２ａ とＲ _６３ａ は、互いに連結して環を形成してもよい。
Ｒ _６４ａ は、水素原子、フッ素原子又はアルキル基を表す。

一般式（ＣＳ−１）〜（ＣＳ−３）に於いて、
Ｒ _１２ 〜Ｒ _２６ は、各々独立に、アルキル基又はシクロアルキル基を表す。
Ｌ _３ 〜Ｌ _５ は、単結合又は２価の連結基を表す。
ｎは、１〜５の整数を表す。

一般式（Ｉａ）に於いて、
Ｒｆは、フッ素原子又は少なくとも１つの水素原子がフッ素原子で置換されたアルキル基を表す。
Ｒ _１ は、アルキル基を表す。
Ｒ _２ は、水素原子又はアルキル基を表す。

〔一般式（２）において、Ｒ ^３ は水素、メチル基又はトリフルオロメチル基を示す。各々のＲ ^４ は相互に独立に炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体、又は炭素数１〜４の直鎖状若しくは分岐状のアルキル基を示す。また、いずれか２つのＲ ^４ が相互に結合して、それぞれが結合している炭素原子と共に２価の脂環式炭化水素基若しくはその誘導体を形成してもよい。〕
〔２〕
疎水性樹脂（Ｃ）が、上記一般式（Ｆ３ａ）で表される基を有する（メタ）アクリレートによる繰り返し単位を有することを特徴とする上記〔１〕に記載のレジスト組成物。
〔３〕
（Ａ）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）疎水性樹脂及び
（Ｄ）溶剤
を含有するレジスト組成物であって、
疎水性樹脂（Ｃ）が、下記一般式（ＩＩ）で表される繰り返し単位及び下記一般式（ＩＩＩ）で表される繰り返し単位を有し、
疎水性樹脂（Ｃ）を含有しないレジスト膜の後退接触角が、５０度以上であることを特徴とするレジスト組成物。

一般式（ＩＩ）及び（ＩＩＩ）に於いて、
Ｒｆは、フッ素原子又は少なくとも１つの水素原子がフッ素原子で置換されたアルキル基を表す。
Ｒ _３ は、アルキル基、シクロアルキル基、アルケニル基又はシクロアルケニル基を表す。
Ｒ _４ は、アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基、トリアルキルシリル基又は環状シロキサン構造を有する基を表す。
Ｌ _６ は、単結合又は２価の連結基を表す。
ｍ及びｎは、繰り返し単位の比率を表す数字であり、０＜ｍ＜１００、０＜ｎ＜１００である。
〔４〕
樹脂（Ａ）が、下記一般式（Ｉ）で表される非酸分解性繰り返し単位を有することを特徴とする上記〔１〕〜〔３〕のいずれか１項に記載のレジスト組成物。

一般式（Ｉ）に於いて、
Ｘａ _１ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ａは、単結合又は２価の連結基を表す。
ＡＣＧは、非酸脱離性炭化水素基を表す。
〔５〕
一般式（Ｉ）で表される非酸分解性繰り返し単位が、下記一般式（Ｉ−１）で表される非酸分解性繰り返し単位であることを特徴とする上記〔４〕に記載のレジスト組成物。

一般式（Ｉ−１）に於いて、
Ｘａ _２ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｘ _５ は、アルキル基又はシクロアルキル基を表す。
ｎ _３ は、４〜７の整数を表す。
ｎ _４ は、０〜３の整数を表す。
ｎ _４ が２以上の整数の場合に、Ｒｘ _５ の内の少なくとも２つが、結合して環構造を形成してもよい。
〔６〕
（Ａ）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）疎水性樹脂及び
（Ｄ）溶剤
を含有するレジスト組成物であって、
樹脂（Ａ）が、下記一般式（Ｉ’）で表される非酸分解性繰り返し単位を有し、
樹脂（Ａ）が、ラクトン構造を有する基を有する繰り返し単位を、樹脂（Ａ）の全繰り返し単位中１０〜４０モル％で有し、
疎水性樹脂（Ｃ）の添加量が、レジスト組成物の全固形分を基準として、０．１〜１０質量％であり、
疎水性樹脂（Ｃ）を含有しないレジスト膜の後退接触角が、５０度以上であることを特徴とするレジスト組成物。

一般式（Ｉ’）に於いて、
Ｘａ _１ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ａは、単結合又は２価の連結基を表す。
ＡＣＧ’は、炭素原子と水素原子のみからなる非酸脱離性炭化水素基を表す。
〔７〕
一般式（Ｉ’）で表される非酸分解性繰り返し単位が、下記一般式（Ｉ’−１）で表される非酸分解性繰り返し単位であることを特徴とする上記〔６〕に記載のレジスト組成物。

一般式（Ｉ’−１）に於いて、
Ｘａ _２ は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Ｒｘ _５ ’は、無置換アルキル基又は無置換シクロアルキル基を表す。
ｎ _３ は、４〜７の整数を表す。
ｎ _４ は、０〜３の整数を表す。
ｎ _４ が２以上の整数の場合に、Ｒｘ _５ ’の内の少なくとも２つが、結合して環構造を形成してもよい。
〔８〕
疎水性樹脂（Ｃ）が、フッ素原子及び珪素原子の少なくともいずれかを有することを特徴とする上記〔６〕又は〔７〕に記載のレジスト組成物。
〔９〕
疎水性樹脂（Ｃ）が、下記の樹脂（Ｃ−１）〜（Ｃ−６）から選ばれるいずれかの樹脂であることを特徴とする上記〔６〕〜〔８〕のいずれか１項に記載のレジスト組成物。
（Ｃ−１）フルオロアルキル基を有する繰り返し単位（ａ）を有する樹脂。
（Ｃ−２）トリアルキルシリル基又は環状シロキサン構造を有する繰り返し単位（ｂ）を有する樹脂。
（Ｃ−３）フルオロアルキル基を有する繰り返し単位（ａ）と、分岐状アルキル基、シクロアルキル基、分岐状アルケニル基、シクロアルケニル基又はアリール基を有する繰り返し単位（ｃ）とを有する樹脂。
（Ｃ−４）トリアルキルシリル基又は環状シロキサン構造を有する繰り返し単位（ｂ）と、分岐状アルキル基、シクロアルキル基、分岐状アルケニル基、シクロアルケニル基又はアリール基を有する繰り返し単位（ｃ）とを有する樹脂。
（Ｃ−５）フルオロアルキル基を有する繰り返し単位（ａ）と、トリアルキルシリル基又は環状シロキサン構造を有する繰り返し単位（ｂ）とを有する樹脂。
（Ｃ−６）フルオロアルキル基を有する繰り返し単位（ａ）と、トリアルキルシリル基又は環状シロキサン構造を有する繰り返し単位（ｂ）と、分岐状アルキル基、シクロアルキル基、分岐状アルケニル基、シクロアルケニル基又はアリール基を有する繰り返し単位（ｃ）とを有する樹脂。
〔１０〕
疎水性樹脂（Ｃ）を含有しないレジスト膜の後退接触角が、５５度以上であることを特徴とする上記〔１〕〜〔９〕のいずれか１項に記載のレジスト組成物。
〔１１〕
樹脂（Ａ）が、脂環構造を有する（メタ）アクリレートによる繰り返し単位を有し、その総含有量が４０モル％以上であることを特徴とする上記〔１〕〜〔１０〕のいずれか１項に記載のレジスト組成物。
〔１２〕
上記〔１〕〜〔１１〕のいずれか１項に記載のレジスト組成物により形成されたレジスト膜。
〔１３〕
上記〔１２〕に記載のレジスト膜を液浸露光、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。
本発明は上記〔１〕〜〔１３〕の構成を有するものであるが、以下その他についても参考のため記載した。 The present invention is as follows.
[1]
(A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a hydrophobic resin and
(D) Solvent
A resist composition comprising:
The hydrophobic resin (C) is a resin having a group represented by the following general formula (F3a), a resin having a group represented by any of the following general formulas (CS-1) to (CS-3), or And a resin having a repeating unit represented by the following general formula (Ia) (however, from a hydrophobic resin (C), a resin having a repeating unit represented by the following general formula (2), and 1,1 , 1,3,3,3-hexafluoro-2-hydroxyisopropyl group ( excluding a resin having —C (CF ₃ ) ₂ OH),
The addition amount of the hydrophobic resin (C) is 0.1 to 10% by mass based on the total solid content of the resist composition,
A resist composition comprising a resist film containing no hydrophobic resin (C) having a receding contact angle of 50 degrees or more.

In general formula (F3a),
R _62a and R _63a each independently represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R _62a and R _63a may be connected to each other to form a ring.
R _64a represents a hydrogen atom, a fluorine atom or an alkyl group.

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents an alkyl group or a cycloalkyl group.
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group.
n represents an integer of 1 to 5.

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

[In General Formula (2), R ³ represents hydrogen, a methyl group, or a trifluoromethyl group. Each R ⁴ independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms. Further, any two R ⁴ may be bonded to each other to form a divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom to which each R ⁴ is bonded. ]
[2]
The resist composition as described in [1] above, wherein the hydrophobic resin (C) has a repeating unit of (meth) acrylate having a group represented by the general formula (F3a).
[3]
(A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a hydrophobic resin and
(D) Solvent
A resist composition comprising:
The hydrophobic resin (C) has a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III),
A resist composition comprising a resist film containing no hydrophobic resin (C) having a receding contact angle of 50 degrees or more.

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
m and n are numbers representing the ratio of repeating units, and 0 <m <100 and 0 <n <100.
[4]
Resin (A) has a non-acid-decomposable repeating unit represented by the following general formula (I), The resist composition of any one of said [1]-[3] characterized by the above-mentioned.

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
A represents a single bond or a divalent linking group.
ACG represents a non-acid-eliminable hydrocarbon group.
[5]
The resist according to [4], wherein the non-acid-decomposable repeating unit represented by the general formula (I) is a non-acid-decomposable repeating unit represented by the following general formula (I-1): Composition.

In general formula (I-1),
Xa ₂ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
Rx ₅ represents an alkyl group or a cycloalkyl group.
n ₃ represents an integer of 4-7.
n ₄ represents an integer of 0 to 3.
When n ₄ is an integer of 2 or more, at least two of Rx ₅ may be bonded to form a ring structure.
[6]
(A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a hydrophobic resin and
(D) Solvent
A resist composition comprising:
Resin (A) has a non-acid-decomposable repeating unit represented by the following general formula (I ′),
The resin (A) has a repeating unit having a group having a lactone structure at 10 to 40 mol% in all repeating units of the resin (A),
The addition amount of the hydrophobic resin (C) is 0.1 to 10% by mass based on the total solid content of the resist composition,
A resist composition comprising a resist film containing no hydrophobic resin (C) having a receding contact angle of 50 degrees or more.

In general formula (I ′),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
A represents a single bond or a divalent linking group.
ACG ′ represents a non-acid-eliminable hydrocarbon group consisting only of carbon atoms and hydrogen atoms.
[7]
[6] The non-acid-decomposable repeating unit represented by the general formula (I ′) is a non-acid-decomposable repeating unit represented by the following general formula (I′-1). Resist composition.

In general formula (I′-1),
Xa ₂ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
Rx ₅ ′ represents an unsubstituted alkyl group or an unsubstituted cycloalkyl group.
n ₃ represents an integer of 4-7.
n ₄ represents an integer of 0 to 3.
When n ₄ is an integer of 2 or more, at least two of Rx ₅ ′ may combine to form a ring structure.
[8]
The resist composition as described in [6] or [7] above, wherein the hydrophobic resin (C) has at least one of a fluorine atom and a silicon atom.
[9]
The hydrophobic resin (C) is any resin selected from the following resins (C-1) to (C-6), wherein any one of the above [6] to [8] The resist composition as described.
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group.
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-3) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group.
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group Having a resin.
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-6) a repeating unit (a) having a fluoroalkyl group, a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl Having a repeating unit (c) having a group or an aryl group.
[10]
The resist composition according to any one of [1] to [9] above, wherein the receding contact angle of the resist film not containing the hydrophobic resin (C) is 55 degrees or more.
[11]
Any one of the above [1] to [10], wherein the resin (A) has a repeating unit of (meth) acrylate having an alicyclic structure, and the total content thereof is 40 mol% or more. The resist composition according to item.
[12]
The resist film formed with the resist composition of any one of said [1]-[11].
[13]
A pattern forming method comprising the steps of immersion exposure and development of the resist film described in [12].
The present invention has the above-mentioned configurations [1] to [13], and the other is described below for reference.

(1) (A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
A resist composition characterized in that the receding contact angle of a resist film containing (C) a hydrophobic resin and (D) a solvent and not containing the hydrophobic resin (C) is 50 degrees or more.

  (2) The resist composition as described in (1), wherein the hydrophobic resin (C) has at least one of a fluorine atom and a silicon atom.

  (3) The resist composition according to (1) or (2), wherein the receding contact angle of the resist film not containing the hydrophobic resin (C) is 55 degrees or more.

  (4) The resist composition according to any one of (1) to (3), wherein the hydrophobic resin (C) has a group represented by the following general formula (F3a).

In general formula (F3a),
R _62a and R _63a each independently represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R _62a and R _63a may be connected to each other to form a ring.
R _64a represents a hydrogen atom, a fluorine atom or an alkyl group.

  (5) The resist composition as described in (4), wherein the hydrophobic resin (C) has a repeating unit of (meth) acrylate having a group represented by the general formula (F3a).

  (6) The hydrophobic resin (C) has groups represented by the following general formulas (CS-1) to (CS-3), according to any one of (1) to (3), Resist composition.

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents an alkyl group or a cycloalkyl group.
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group.
n represents an integer of 1 to 5.

(7) The hydrophobic resin (C) is any one selected from the following resins (C-1) to (C-6): (1) to (3) The resist composition as described.
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group.
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-3) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group.
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group Having a resin.
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-6) a repeating unit (a) having a fluoroalkyl group, a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl Having a repeating unit (c) having a group or an aryl group.

  (8) The resist composition according to any one of (1) to (3), wherein the hydrophobic resin (C) has a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

  (9) The hydrophobic resin (C) has a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III) (1) to (3) The resist composition according to any one of the above.

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
m and n are numbers representing the ratio of repeating units, and 0 <m <100 and 0 <n <100.

  (10) Any of (1) to (9), wherein the resin (A) has a repeating unit of (meth) acrylate having an alicyclic structure, and the total content thereof is 40 mol% or more. A resist composition according to claim 1.

  (11) The resist composition as described in any one of (1) to (10), wherein the resin (A) has a non-acid-decomposable repeating unit represented by the following general formula (I).

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
A represents a single bond or a divalent linking group.
ACG represents a non-acid-eliminable hydrocarbon group.

  (12) The non-acid-decomposable repeating unit represented by the general formula (I) is a non-acid-decomposable repeating unit represented by the following general formula (I-1). Resist composition.

In general formula (I-1),
Xa ₂ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
Rx ₅ represents an alkyl group or a cycloalkyl group.
n ₃ represents an integer of 4-7.
n ₄ represents an integer of 0 to 3.
When n ₄ is an integer of 2 or more, at least two of Rx ₅ may be bonded to form a ring structure.

  (13) A pattern forming method comprising a step of forming a resist film from the resist composition according to any one of (1) to (12), immersion exposure, and development.

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

(14) Any of (1) to (12), wherein the hydrophobic resin (C) has a molecular weight dispersity of 1.3 or less and a weight average molecular weight of 1.0 × 10 ⁴ or less. The resist composition described in 1.

  (15) When the weight average molecular weight of the resin (A) is Mw (A) and the weight average molecular weight of the hydrophobic resin (C) is Mw (C), Mw (A) −Mw (C) ≧ 2000 is satisfied. The resist composition according to any one of (1) to (12) and (14).

  According to the present invention, in immersion exposure, a resist having a large receding contact angle with respect to the immersion liquid, good pattern shape, improved line edge roughness, and suppression of acid elution into the immersion liquid. A composition and a pattern forming method using the resist composition can be provided.

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

(A) Resin whose solubility in an alkaline developer is increased by the action of an acid The resin whose solubility in an alkali developer is increased by the action of an acid used in the resist composition of the present invention is the main chain or side chain of the resin, or A resin (also referred to as “resin (A)”) having a group (hereinafter also referred to as “acid-decomposable group”) that decomposes by the action of an acid to generate an alkali-soluble group in both the main chain and the side chain. A resin having a monocyclic or polycyclic alicyclic hydrocarbon structure in the side chain and increasing the solubility in an alkali developer by the action of an acid is preferable.
Examples of the acid-decomposable group include a group in which a hydrogen atom of an alkali-soluble group is protected with a group capable of leaving by the action of an acid.
Examples of alkali-soluble groups include phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl). ) Imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene Groups and the like.
Preferred alkali-soluble groups include carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), and sulfonic acid groups.
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 acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The resist composition of the present invention containing a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure in the side chain and increasing the solubility in an alkaline developer by the action of an acid is irradiated with ArF excimer laser light. Can be suitably used.

  The resin (A) preferably has a repeating unit represented by the following general formula (I).

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
A represents a single bond or a divalent linking group.
ACG represents a non-acid-eliminable hydrocarbon group.

In general formula (I), the alkyl group of Xa ₁ is preferably an alkyl group having 1 to 5 carbon atoms and may be substituted with a hydroxyl group, a halogen atom, or the like.
Xa ₁ is preferably a hydrogen atom or a methyl group.
Preferred divalent linking group of A, -CO ₂ - and -CO ₂ where the alkylene groups are linked - alkylene group - a. The alkylene group in —CO ₂ -alkylene group—has two hydrogen atoms from methylene and norbornane to form a divalent linking group, and two hydrogen atoms from adamantane to form a divalent linking group. The basis is mentioned.
The non-acid-eliminable hydrocarbon group of ACG may be any hydrocarbon group that does not desorb from the oxygen atom in the formula by the action of an acid, but is a hydrocarbon group consisting of only carbon and hydrogen atoms. It is more preferable that it does not have a polar substituent. Examples of the non-acid-eliminable hydrocarbon group of ACG include a linear or branched alkyl group that does not desorb from an oxygen atom in the formula by the action of an acid, and a monocyclic or polycyclic cycloalkyl group. Specifically, a linear or branched alkyl group having 1 to 10 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, isobutyl group, neopentyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, etc. A monocyclic cycloalkyl group having 3 to 10 carbon atoms, such as a monocyclic cycloalkyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, a diamantyl group, and a tetrahydrodecalin group. Alkyl groups are preferred. The linear or branched alkyl group may be further substituted with a monocyclic or polycyclic cycloalkyl group as a substituent. The monocyclic or polycyclic cycloalkyl group may be further substituted with a linear or branched alkyl group or a monocyclic or polycyclic cycloalkyl group as a substituent.

  The non-acid-decomposable repeating unit represented by the general formula (I) is preferably a non-acid-decomposable repeating unit represented by the following general formula (I-1).

In general formula (I-1),
Xa ₂ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
Rx ₅ represents an alkyl group or a cycloalkyl group.
n ₃ represents an integer of 4-7.
n ₄ represents an integer of 0 to 3.
When n ₄ is an integer of 2 or more, at least two of Rx ₅ may be bonded to form a ring structure.

Formula (I-1) in the, Xa ₂ is in the formula (I), Xa ₁ synonymous.
Examples of the alkyl group of Rx ₅ include linear or branched alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and t-butyl group. preferable.
The cycloalkyl group rx _5, cyclopentyl group, a monocyclic cycloalkyl group having 3 to 10 carbon atoms such as a cyclohexyl group, a norbornyl group, tetra tricyclodecanyl group, tetracyclododecanyl group, carbon atoms such as adamantyl group 7-15 polycyclic cycloalkyl groups are preferred.
The ring structure formed by bonding at least two of Rx ₅ includes a monocyclic ring structure having 3 to 10 carbon atoms such as cyclopentane ring and cyclohexane ring, norbornane ring, tetracyclodecane ring, tetracyclo A polycyclic ring structure having 7 to 15 carbon atoms such as a dodecane ring and an adamantane ring is preferred.

  As a monomer corresponding to the non-acid-decomposable repeating unit represented by the general formula (I) or the general formula (I-1), for example, acrylic acid esters, methacrylic acid esters, allyl compounds, vinyl ethers, Examples include compounds having one addition polymerizable unsaturated bond selected from vinyl esters and the like.

  Specific examples of the non-acid-decomposable repeating unit represented by the general formula (I) or the general formula (I-1) are shown below, but the present invention is not limited thereto.

In the above specific examples, Xa represents H, CH ₃ , CF ₃ or CH ₂ OH.

  In the above specific examples, (ACG-2), (ACG-6), (ACG-7), (ACG-8), (ACG-9), (ACG-12), (ACG-16), ( ACG-17), (ACG-18), (ACG-19), (ACG-20), (ACG-22), (ACG-23), (ACG-24), (ACG-26), (ACG- 27), (ACG-28), (ACG-29), (ACG-30), and (ACG-31) are particularly preferable.

  Content of the repeating unit represented by general formula (I) or (I-1) is 1-80 mol% normally, Preferably it is 5-50 mol%, More preferably, it is 5-40 mol%. is there. By setting the content to 5 to 40 mol%, it is possible to reduce elution of low molecular components from the resist film to the immersion liquid during immersion exposure.

By introducing the repeating unit represented by the general formula (I) or (I-1), the performance required for the resin (A), in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition temperature),
(3) Solubility in positive developer and negative developer,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. are improved.

  The resin (A) is preferably a resin having a repeating unit represented by the following general formula (NGH-1).

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group (preferably having 1 to 4 carbon atoms).
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

In the general formula (NGH-1), R _NGH1 is preferably _a hydrogen atom, a methyl group or an ethyl group. R _NGH1 is more preferably _a methyl group.
_{Of RNGH2 to RNGH4} , preferably one or two are hydroxyl groups and the rest are hydrogen atoms.

  Content of the repeating unit represented by general formula (NGH-1) is 1-15 mol% normally, Preferably it is 5-15 mol%. By setting the content to 1 to 15 mol%, the affinity for the negative developer and the positive developer is improved.

  Resin (A) has a repeating unit represented by the general formula (NGH-1), whereby the substrate adhesion and the developer affinity are improved.

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

  The resin (A) includes a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and a repeating unit represented by the following general formula (II-AB). A resin containing at least one selected from the group 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. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. 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 , an acid-decomposable group, —C (═O) —XA′—R ₁₇ ′, An alkyl group or a cycloalkyl group is represented. At least two of R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
Here, 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) and R _{12 to} R ₂₅ , the alkyl group is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, Examples include 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 _{11 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.

As further substituents of these alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers) 2-6). 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) can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a structure in which a hydrogen atom of a carboxyl group, a sulfonic acid group, a phenolic hydroxyl group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (pV), preferably a carboxyl group The hydrogen atom of the sulfonic acid group is substituted with the structure represented by the general formulas (pI) to (pV).

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

In the general formula (pA),
R represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). A plurality of R may be the same or different.
A 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.
Rp ₁ represents any one of the general formulas (pI) to (pV).

  The repeating unit represented by formula (pA) is particularly preferably 2-alkyl-2-adamantyl (meth) acrylate, dialkyl (1-adamantyl) methyl (meth) acrylate, dialkyl (1-cyclohexyl) methyl (meth) ) Repeating unit by acrylate.

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

Examples of the halogen atom in the general formula (II-AB), R ₁₁ ′, and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Examples of the alkyl group for R ₁₁ ′ and R ₁₂ ′ include linear or branched alkyl groups 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 a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include 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 various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).
That is, in the general formula (II-AB1) or the general formula (II-AB2), various substituents of R ₁₃ ′ to R ₁₆ ′ have the alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming an atomic group for forming or 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 resin (A) preferably has a lactone group. As the lactone group, any group can be used as long as it has a lactone structure, but a group having a 5- to 7-membered ring lactone structure is preferable, and a bicyclo structure is added to the 5- to 7-membered ring lactone structure. Those in which other ring structures are condensed to form a spiro structure are preferred. The following general formulas (LC1-1) to (LC1
It is more preferable to have a repeating unit having a group having a lactone structure represented by any one of -16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are groups represented by general formulas (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), and (LC1-14). By using a specific lactone structure, line edge roughness and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , 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 (LC1-16), R _{13 in the} above general formula (II-AB1) or (II-AB2) may be used. Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16) or 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.
The alkyl group for Rb ₀ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms and may have a substituent. 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 represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these. A linking group represented by a single bond or —Ab ₁ —CO ₂ — is preferable. Ab ₁ is a linear or branched alkylene group, a monocyclic or polycyclic cycloalkylene group, and preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group.
V represents a group 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 resin (A) is substituted with a repeating unit having an organic group having a polar group other than the alicyclic hydrocarbon group having a hydroxyl group in the repeating unit represented by the general formula (NGH-1), in particular, with a polar group. It may have a repeating unit having an alicyclic hydrocarbon structure. Thereby, the substrate adhesion is further improved. 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 carboxyl group and a cyano group are preferable.
As the alicyclic hydrocarbon structure substituted with a polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

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

As the repeating unit having a group represented by general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in general formula (II-AB1) or (II-AB2) is generally Those having groups represented by formulas (VIIa) to (VIId) (for example, R ₅ in —COOR ₅ represents groups represented by general formulas (VIIa) to (VIId)), or the following general formula (AIIa ) To (AIId).

In general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R _2c to R _4c have the same meanings as R _2c to R _4c in formulas (VIIa) ~ (VIIc).

  Although the specific example of the repeating unit which has a structure represented by general formula (AIIa)-(AIId) is given to the following, this invention is not limited to these.

  Resin (A) may have a repeating unit represented by the following general formula (VIII).

In 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 resin (A) may have a repeating unit having an alkali-soluble group, and in that case, it is more preferable to have a repeating unit having a carboxyl group. By having 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. Either a repeating unit that is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain at the time of polymerization, and the linking group is a monocyclic or polycyclic hydrocarbon. You may have a structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  The resin (A) 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.

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-decomposable protecting 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 cyclopentylene group, a cyclohexylene group, or a norbornylene group.

  Specific examples of the repeating unit having a group represented by the general formula (F1) are shown below, but the present invention is not limited thereto.

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

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

The following are mentioned as a preferable aspect of resin (A).
(1) One having a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV) (side chain type).
Preferably, those having a (meth) acrylate repeating unit having a structure of (pI) to (pV).
(2) Those having a repeating unit represented by 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 the general formula (II-AB), a maleic anhydride derivative-based repeating unit, and a repeating unit having a (meth) acrylate structure (hybrid type).

  In the resin (A), the acid-decomposable group is represented by the general formula (II-AB), which is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). The repeating unit can be contained in at least one repeating unit among the repeating units of the copolymer component. The acid-decomposable group is preferably contained in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formula (pI) to general formula (pV).

In the resin (A), the content of the repeating unit having an acid-decomposable group is 1 in all repeating structural units.
0-60 mol% is preferable, More preferably, it is 20-50 mol%, More preferably, it is 25-40 mol%.

  In the resin (A), the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is preferably 20 to 70 mol% in all repeating structural units, More preferably, it is 20-50 mol%, More preferably, it is 25-40 mol%.

  In the resin (A), the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 in all repeating structural units. ˜50 mol%.

In the resin (A), the content of the repeating unit having a group having a lactone structure is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, still more preferably 25 to 40 mol% in all repeating structural units. It is.
In the resin (A), the content of the repeating unit having an organic group having a polar group is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 5 to 20 mol in all repeating structural units. %.

  Further, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can be appropriately set according to the performance of the desired resist. Generally, the general formula (pI) 99 mol% or less based on 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). More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

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

  The resin (A) is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, and all of the repeating units may be any mixture of methacrylate repeating units / acrylate repeating units, It is preferable that the acrylate repeating unit is 50 mol% or less of the entire repeating unit.

  The resin (A) includes at least a (meth) acrylate repeating unit having a group having a lactone structure, a (meth) acrylate repeating unit having an organic group substituted with at least one of a hydroxyl group and a cyano group, and an acid. A copolymer having three types of repeating units of a (meth) acrylate-based repeating unit having a degradable group is preferable.

  Preferably, 20 to 50 mol% of repeating units having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), 20 to 50 mol% of repeating units having a group having a lactone structure, and polarity It is a ternary copolymer containing 5 to 30% of repeating units having an alicyclic hydrocarbon structure substituted with a group, or a quaternary copolymer containing 0 to 20% of other repeating units.

Particularly preferable resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-7), and the following general formulas (ARL-1) to (ARL- 7) The alicyclic hydrocarbon structure substituted with 20 to 50 mol% of repeating units having a group having a lactone structure represented by formula (ARH-1) to (ARH-3) shown below. A terpolymer copolymer containing 5 to 30 mol% of repeating units, or a carboxyl group, a repeating unit having a structure represented by the general formula (F1) or an alicyclic hydrocarbon structure, and having an acid decomposability. It is a quaternary copolymer containing 5 to 20 mol% of repeating units not shown.

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, and Rxa ₁ and Rxb ₁ represent a methyl group or an ethyl group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxd ₁ represents a hydrogen atom or a methyl group, and Rxe ₁ represents a trifluoromethyl group, a hydroxyl group, or a cyano group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group.)

  Resin (A) 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 heating is performed, 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 60-100 ° C.
For purification, the same method as that for the resin (C) described later can be used. The liquid-liquid extraction method for removing residual monomers and oligomer components by combining water washing and an appropriate solvent, only those having a specific molecular weight or less. A purification method in a solution state such as ultrafiltration to extract and remove the residual monomer by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent, A usual method such as a purification method in a solid state, such as washing the filtered resin slurry with a poor solvent, can be applied.

The weight average molecular weight of the resin (A) is preferably from 1,000 to 200,000, more preferably from 3,000 to 20,000, and most preferably from 5,000 to 15, as a polystyrene-converted value by the GPC method. 000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
Another particularly preferable form of the weight average molecular weight of the resin (A) is 3,000 to 9,500 in terms of polystyrene by GPC method. By setting the weight average molecular weight to 3,000 to 9,500, resist residues (hereinafter also referred to as “scum”) are particularly suppressed, and a better pattern can be formed.
The degree of dispersion (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, particularly preferably 1.2 to 2.0. . The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.

In the resist composition of the present invention, the blending amount of the resin (A) in the entire composition is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass in the total solid content.
In the present invention, the resin (A) may be used alone or in combination.

  The resin (A) may have a fluorine atom or silicon atom content of 40% by mass or less from the viewpoint of improving compatibility with the compound (B) and the hydrophobic resin (C), and further from preventing repelling of the developer. Preferably, it is 10 mass% or less.

  The receding contact angle of the resist film not containing the hydrophobic resin (C) can be adjusted by the repeating unit, terminal structure, molecular weight, etc. of the resin (A), but the monocyclic or polycyclic alicyclic hydrocarbon structure The repeating unit having high hydrophobicity can easily increase the receding contact angle. The repeating unit of the resin (A) is preferably a (meth) acrylate unit having an alicyclic structure, and the total content thereof is 40 mol% to 100 mol%, more preferably 40 mol% to 80 mol%.

The receding contact angle of the resist film not containing the hydrophobic resin (C) is 50 degrees or more, preferably in the range of 50 degrees to 80 degrees. More preferably, it is 55 degrees to 80 degrees, thereby reducing the number of development defects and improving the pattern collapse performance.
The receding contact angle defined here is the receding contact angle measured by the expansion and contraction method. Specifically, after making 36 μL of water droplets with a syringe on the resist composition prepared on the silicon wafer, 6 μL / sec. The contact angle during suction shows a stable value. The measurement temperature is 25 ° C.

(B) Compound that generates acid upon irradiation with actinic ray or radiation The resist composition of the present invention contains 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

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

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

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

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include a compound (ZI-1) described later.
), (ZI-2) and (ZI-3).

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 compounds, namely, compounds containing an arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or R ₂₀₁
Some of to R ₂₀₃ is an aryl group and the remainder may be an alkyl group or a cycloalkyl group.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Among acid generators, particularly preferred examples are given below.

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

(C) Hydrophobic resin When exposing the resist film which consists of a resist composition of this invention through an immersion medium, hydrophobic resin (C) can be further added as needed. “Hydrophobic resin” refers to a resin that, when added to a resist film, contributes to an improvement in the contact angle of the resist film surface with water. The hydrophobic resin may be any resin as long as the receding contact angle of the surface is improved by the addition, but the hydrophobic resin has at least one of fluorine atoms and silicon atoms and is unevenly distributed in the resist film surface layer. preferable.
The advancing contact angle of the resist film is preferably adjusted to 70 ° to 120 °, and more preferably 75 ° to 100 °. The receding contact angle is preferably adjusted to 60 ° to 100 °, more preferably 70 ° to 90 °.
The addition amount of the hydrophobic resin (C) can be adjusted as appropriate so that the receding contact angle of the resist film falls within the above range, but is 0.1 to 10% by mass based on the total solid content of the resist composition. Preferably, it is 0.1-5 mass%.
It is preferable to contribute to improving the receding contact angle with a smaller addition amount, and the glass transition point (Tg) of the resin is preferably 0 ° C. or higher.
The hydrophobic resin (C) is preferably a solid at room temperature (25 ° C.).
The advancing contact angle and receding contact angle defined here are advancing and receding contact angles measured by the expansion and contraction method. Specifically, a 36 μL water droplet is created with a syringe on a resist composition prepared on a silicon wafer. After that, discharge or suction is performed at a speed of 6 μL / sec, and the contact angle during discharge / suction shows a stable value. The measurement temperature is 25 ° C.
Hydrophobic resin (C) is often ubiquitous at the interface, but unlike surfactants, it does not necessarily have a hydrophilic group in the molecule and contributes to uniform mixing of polar / nonpolar substances. You don't have to.

As the hydrophobic resin (C), a resin having at least one of a fluorine atom and a silicon atom is preferable.
The fluorine atom or silicon atom in the hydrophobic resin (C) may be present in the main chain of the resin or may be substituted on the side chain.
Hydrophobic resin (C) may be insoluble or soluble in alkaline developer “Insoluble in alkaline developer” means 2.38 wt% tetramethyl at 23 ° C. of the membrane made of hydrophobic resin (C). The amount dissolved in an aqueous ammonium hydroxide solution is 10 nm or less when accumulated for 30 seconds from the start of development.
“Soluble in alkaline developer” means that the amount of the hydrophobic resin (C) film dissolved in an aqueous 2.38 wt% tetramethylammonium hydroxide solution at 23 ° C. is 50 nm or more in 30 seconds from the start of development. Say that. In order to be soluble in an alkali developer, it is necessary that the resist film has an alkali-soluble group in the development step.
The alkali-soluble group may be previously contained in the resin (A) and / or the hydrophobic resin (C) in the resist composition, or may be generated by the action of an acid during the exposure to development process. Then, it may react with an alkali developer to generate an alkali-soluble group.

The hydrophobic resin (C) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, It may have a substituent.
The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.
Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and may further have another substituent.

  Preferred examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom include groups represented by the following general formulas (F2) to (F4). The present invention is not limited to this.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. Provided that at least one of R _{57 to} R ₆₁ , at least one of R _{62 to} R ₆₄ and at least one of R _{65 to} R ₆₈ are fluorine atoms or at least one hydrogen atom is a fluorine atom. Represents an alkyl group (preferably having 1 to 4 carbon atoms) substituted with. R _{57 to} R ₆₁ are preferably all fluorine atoms. R _{65 to} R ₆₇ are preferably all fluorine atoms, and R ₆₈ is preferably a trifluoromethyl group. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include, for example, trifluoromethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2 2,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -C (CF _{3) 2} OH is preferred.

Hereinafter, although the specific example of the repeating unit which has a fluorine atom is shown, this invention is not limited to this.
In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .
X ₂ represents —F or —CF ₃ .

The hydrophobic resin (C) is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure as a partial structure having a silicon atom.
Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents an alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. The divalent linking group is selected from the group consisting of an alkylene group, a phenylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group or a urea group, or a combination of two or more groups. Is mentioned.
n represents an integer of 1 to 5.

Hereinafter, although the specific example of the repeating unit which has a silicon atom is given, this invention is not limited to this.
In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .

Furthermore, the hydrophobic resin (C) may have at least one group selected from the following groups (x) to (z).
(X) an alkali-soluble group,
(Y) a group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer, and (z) a group that decomposes by the action of an acid.

(X) Alkali-soluble groups include phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkyl Carbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) A methylene group etc. are mentioned.
Preferred alkali-soluble groups include fluorinated alcohol groups (preferably hexafluoroisopropanol groups), sulfonimide groups, and bis (carbonyl) methylene groups.

  As the repeating unit having an alkali-soluble group (x), a repeating unit in which an alkali-soluble group is bonded directly to the main chain of the resin, such as a repeating unit by acrylic acid, a repeating unit by methacrylic acid, or a linking group It is preferable to use a repeating unit in which an alkali-soluble group is bonded to the main chain of the resin, and further introduce a polymerization initiator or chain transfer agent having an alkali-soluble group at the end of the polymer chain during polymerization.

  The content of the repeating unit having an alkali-soluble group (x) is preferably from 1 to 50 mol%, more preferably from 3 to 35 mol%, still more preferably from 5 to 20 mol%, based on all repeating units in the polymer.

  Specific examples of the repeating unit having an alkali-soluble group (x) are shown below, but the present invention is not limited thereto.

(Y) Examples of the group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer include a lactone group, an acid anhydride group, an acid imide group, and the like, preferably a lactone group. .
The repeating unit having a group (y) that decomposes by the action of an alkali developer and increases the solubility in the alkali developer includes a group that decomposes by the action of the alkali developer and increases the solubility in the alkali developer. The main unit of the resin, such as a repeating unit by an acrylate ester having (y), a repeating unit by a methacrylic ester having a group (y) that decomposes by the action of an alkali developer and increases the solubility in an alkali developer. Repeated units in which the group (y) is decomposed to the chain by the action of an alkali developer and increases the solubility in the alkali developer, or decomposed by the action of the alkali developer, and in the alkali developer Either a polymerization initiator having a group (y) whose solubility is increased or a chain transfer agent is used at the time of polymerization and is introduced at the end of the polymer chain.

  The content of the repeating unit having a group (y) that decomposes by the action of the alkali developer and increases the solubility in the alkali developer is preferably from 1 to 40 mol%, more preferably, based on all repeating units in the polymer. Is 3 to 30 mol%, more preferably 5 to 15 mol%.

  Specific examples of the repeating unit having a group (y) that increases the solubility in an alkali developer include those similar to the lactone structure exemplified in the resin (A) and the structure represented by the general formula (VIII). Can be mentioned.

(Z) Examples of the group capable of decomposing by the action of an acid include the same acid-decomposable groups as mentioned for the resin (A). (Z) Examples of the repeating unit having a group capable of decomposing by the action of an acid include those similar to the repeating unit having an acid-decomposable group exemplified in the resin (A).
The content of the repeating unit having a group (z) that decomposes by the action of an acid is preferably from 1 to 80 mol%, more preferably from 10 to 80 mol%, still more preferably based on all repeating units in the hydrophobic resin (C). Is 20 to 60 mol%.

  The hydrophobic resin (C) may further have a repeating unit represented by the following general formula (III).

In general formula (III):
R ₄ represents a group having an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group or a cycloalkenyl group.
L ₆ represents a single bond or a divalent linking group.

In general formula (III), the alkyl group represented by R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The aryl group is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The divalent linking group of L ₆ is preferably an alkylene group (preferably having 1 to 5 carbon atoms), an oxy group, or a carbonyloxy group.

  The hydrophobic resin (C) preferably has a group represented by the following general formula (F3a).

In general formula (F3a),
R _62a and R _63a each independently represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R _62a and R _63a may be connected to each other to form a ring.
R _64a represents a hydrogen atom, a fluorine atom or an alkyl group.

  Examples of the repeating unit having a group represented by the general formula (F3a) include a repeating unit based on an acrylate or a methacrylate having a group represented by the general formula (F3a).

  The hydrophobic resin (C) preferably has a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In general formula (Ia), the alkyl group in which at least one hydrogen atom of Rf is substituted with a fluorine atom preferably has 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.
The alkyl group for R ₁ is preferably a linear or branched alkyl group having 3 to 10 carbon atoms,
A branched alkyl group having 3 to 10 carbon atoms is more preferable.
The alkyl group for R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms.

Hereinafter, although the specific example of the repeating unit represented by general formula (Ia) is given, this invention is not limited to this.
X is, -H, -CH _3, -F, or represents a -CF _3.

  The repeating unit represented by the general formula (Ia) can be formed by polymerizing a compound represented by the following general formula (I).

In general formula (I),
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In the general formula (I), Rf, R ₁ and R ₂ are in the general formula (Ia), Rf, R ₁ and R ₂ synonymous.
As the compound represented by the general formula (I), a commercially available product may be used, or a synthesized product may be used. In the case of synthesis, 2-trifluoromethylmethacrylic acid can be obtained by acidification and then esterification.

  The hydrophobic resin (C) is preferably a resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III).

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
m and n are numbers representing the ratio of repeating units, and 0 <m <100 and 0 <n <100.

Rf in the general formula (II) is the same as Rf in the general formula (Ia).
The alkyl group represented by R ₃ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
m = 30 to 70 and n = 30 to 70 are preferable, and m = 40 to 60 and n = 40 to 60 are more preferable.

  Hereinafter, specific examples of the hydrophobic resin (C) having the repeating unit represented by the general formula (II) and the repeating unit represented by the general formula (III) will be given, but the present invention is limited thereto. is not.

The hydrophobic resin (C) is preferably any resin selected from the following resins (C-1) to (C-6).
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group.
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-3) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group.
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group Having a resin.
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-6) a repeating unit (a) having a fluoroalkyl group, a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl Having a repeating unit (c) having a group or an aryl group.

When the hydrophobic resin (C) has a fluorine atom, the content of the fluorine atom is preferably 5 to 80% by mass, and preferably 10 to 80% by mass with respect to the molecular weight of the hydrophobic resin (C). Is more preferable. Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in hydrophobic resin (C), and it is more preferable that it is 30-100 mass%.
When the hydrophobic resin (C) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass, and 2 to 30% by mass with respect to the molecular weight of the hydrophobic resin (C). Is more preferable. Moreover, it is preferable that it is 10-100 mass% in a hydrophobic resin (C), and, as for the repeating unit containing a silicon atom, it is more preferable that it is 20-100 mass%.

  The weight average molecular weight in terms of standard polystyrene of the hydrophobic resin (C) is preferably 500 to 50000, more preferably 1000 to 15000, still more preferably 1500 to 8000, and particularly preferably 2000 to 6000.

  In the hydrophobic resin (C), as in the case of the resin (A), it is natural that there are few impurities such as metals, and the residual monomer and oligomer components are preferably 0 to 10% by mass, more preferably 0. -5 mass%, 0-1 mass% is still more preferable. Thereby, a resist having no change over time such as foreign matter in liquid or sensitivity can be obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 3, more preferably 1 to 2, in terms of resolution, resist shape, resist pattern sidewall roughness, development scum, and the like. Even more preferably, it is in the range of 1 to 1.6, and particularly preferably in the range of 1 to 1.3.

The difference in weight average molecular weight between the resin (A) and the hydrophobic resin (C) is preferably 2000 or more, more preferably 3000 or more, and particularly preferably 4000 or more. The resin (A) preferably has a larger weight average molecular weight than the hydrophobic resin (C) because the development defect performance is improved. Further, the hydrophobic resin (C) preferably has a molecular weight dispersity of 1.3 or less and a weight average molecular weight of 1.0 × 10 ⁴ or less.

  As the hydrophobic resin (C), various commercially available products can be used, or they can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer and a polymerization initiator are dissolved in a solvent, and a batch polymerization method in which polymerization is performed by heating, a solution of the monomer and the polymerization initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, amides such as dimethylformamide and dimethylacetamide, Includes a solvent that dissolves the composition of the present invention such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone described below. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive 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 the polymerization initiator, the polymerization is started using a commercially available radical polymerization initiator (azo polymerization initiator, peroxide, etc.). As the radical polymerization initiator, an azo polymerization initiator is preferable, and an azo polymerization initiator having an ester group, a cyano group, or a carboxyl group is more preferable. Preferred examples of the polymerization initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The concentration of the solute such as the monomer and the polymerization initiator in the reaction solution is usually 5 to 50% by mass, preferably 30 to 50% by mass. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 60 ° C to 100 ° C.

After completion of the reaction, the mixture is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

  The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer, and may be a hydrocarbon, halogenated hydrocarbon, nitro, depending on the type of polymer. A compound, ether, ketone, ester, carbonate, alcohol, carboxylic acid, water, a mixed solvent containing these solvents, and the like can be appropriately selected for use. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

  In addition, once the resin is precipitated and separated, it may be dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent. That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is contacted to precipitate the resin (step a), the resin is separated from the solution (step b), and the resin solution is dissolved again in the solvent. A is prepared (step c), and then the resin solution A is contacted with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less). It may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).

  Specific examples of the hydrophobic resin (C) are shown below, but the present invention is not limited thereto. Table 1 below shows the composition of repeating units in each resin (molar ratio, corresponding to each repeating unit in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn).

(D) Solvent Solvents that can be used when preparing the resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, lactate alkyl ester, and alkoxypropion. Examples thereof include organic solvents such as alkyl acid, 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, and alkyl pyruvate.

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.

  The solvent is preferably a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

(E) Basic compound The 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 (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring.

About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
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.

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

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undecar 7-ene etc. are mentioned. Examples of the compound having an onium hydroxide structure include 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. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, 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 based on solid content of a 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.

(F) Surfactant The 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, silicon-based surfactant). , A surfactant having both a fluorine atom and a silicon atom), or more preferably two or more.

When the resist composition of the present invention contains the surfactant (F), when using an exposure light source of 250 nm or less, particularly 220 nm or less, a resist pattern with good sensitivity and resolution and less adhesion and development defects can be obtained. It becomes possible to give.
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 and Chemicals), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass ( Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, 352, EF801, EF802, EF601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208, 230G, 208 , Mention may be made of 212D, 218D, the fluorine-based surfactant or silicone-based surfactants such as 222D ((KK) Neos). 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 resist composition whole quantity (except a solvent), More preferably, it is 0.1-5 mass%.

(G) Carboxylic acid onium salt The resist composition in the present invention may contain (G) a carboxylic acid onium salt. Examples of the carboxylic acid onium salt include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, the (G) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, it is preferable that the carboxylate residue of the (H) 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.

  Fluorine-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 (G) 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 generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, and more preferably 1%, based on the total solid content of the composition. -7% by mass.

(H) Other additives The resist composition of the present invention further promotes solubility in dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors, and developers as necessary. The compound to be made (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.

(I) Pattern Forming Method The 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 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 resist composition is generally 1 to 10% by mass, more preferably 1 to 8.0% by mass, and still more preferably 1.0 to 6.0% by mass.

The 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 photosensitive composition is formed by applying and drying a resist composition on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by an appropriate application method such as a spinner or a coater. To do. In addition, you may coat a well-known antireflection film beforehand.
The photosensitive 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., preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 1. Far ultraviolet light having a wavelength of 200 nm, 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), and electron beam are preferable.

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

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

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

  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 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.

  When the resist composition of the present invention is used as a resist film, the receding contact angle of water with respect to the resist film is preferably 70 ° or more. 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.

In order to prevent the resist film from coming into direct contact with the immersion liquid between the resist film of the resist composition of the present invention and the immersion liquid, an immersion liquid hardly soluble film (hereinafter also referred to as “topcoat”).
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. Hydrophobic resin (C) may be used as a top coat. 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.

  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 (1))
Under a nitrogen stream, 8.6 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 9.8 g of 2-adamantyl isopropyl methacrylate, 4.4 g of hydroxyadamantyl methacrylate, 8.9 g of norbornane lactone methacrylate, and 8 mol% of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries) were dissolved in 79 g of cyclohexanone. The solution was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise over 20 minutes to a mixture of 800 m of hexane / 200 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 19 g of Resin (1). The weight average molecular weight of the obtained resin was 8800 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.9.

Similarly, resins (2) to (19) and (R1) to (R3) were synthesized.
Tables 2 to 3 below show the molar ratio of the monomers and repeating units (corresponding in order from the monomer to the left), the weight average molecular weight, and the degree of dispersion in resins (2) to (19) and (R1) to (R3).

Synthesis Example 2 (Synthesis of Resin (C-20))
47.2 g of hexafluoroisopropyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in propylene glycol monomethyl ether acetate to prepare 170 g of a solution having a solid content concentration of 20% by mass. To this solution was added 8 mol% (3.68 g) of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd., and this was heated to 80 ° C. over 4 hours under a nitrogen atmosphere, 20.0 g of propylene glycol monomethyl ether acetate. It was dripped in. After completion of dropping, the reaction solution was stirred for 2 hours to obtain a reaction solution. After completion of the reaction, the reaction solution was cooled to room temperature and dropped into a 20-fold amount of methanol / water = 8/1 mixed solvent. The separated oily compound was recovered by decantation to obtain 24.1 g of the objective resin (C-20).
The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 4000, and the degree of dispersion was 1.4.

Synthesis Example 3 (Synthesis of resin (C-25))
Hexafluoroisopropyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 22.21 g and 4-tert-butylcyclohexyl methacrylate (22.43 g) are dissolved in propylene glycol monomethyl ether acetate to obtain a solution 205.36 having a solid concentration of 20% by mass. g was prepared. To this solution was added 3.0 mol% (1.382 g) of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd., and this was added to 17.86 g of propylene glycol monomethyl ether acetate heated to 80 ° C. for 4 hours under a nitrogen atmosphere. It was dripped. After completion of dropping, the reaction solution was stirred at 80 ° C. for 2 hours. The reaction solution was cooled to room temperature and dropped into a 20 times amount of a mixed solvent of methanol / water = 5/1. The precipitated solid was filtered to obtain 35.6 g of resin (C-25) as the target product.
The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 7800, and the degree of dispersion was 2.0.

Synthesis Example 4 (Synthesis of Resin (C-17))
2,2,3,3,4,4,4-heptefrulbutyl methacrylate (2,2,3,3,4,4,4-heptafluorobutyl
methacrylate) 26.81 g and 4-tert-butylcyclohexyl methacrylate (14.22 g) were dissolved in propylene glycol monomethyl ether acetate to prepare 188.75 g of a solution having a solid concentration of 20% by mass. To this solution was added 3.5 mol% (1.612 g) of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd., and this was added to 16.41 g of propylene glycol monomethyl ether acetate heated at 80 ° C. for 4 hours under a nitrogen atmosphere. It was dripped. After completion of dropping, the reaction solution was stirred at 80 ° C. for 2 hours. The reaction solution was cooled to room temperature and dropped into a 20 times amount of a mixed solvent of methanol / water = 5/1. The precipitated solid was filtered to obtain 38.6 g of the target resin (C-17).
The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 7600, and the degree of dispersion was 2.0.

Examples 1-14 and Comparative Examples 1-3
<Resist preparation>
The components shown in Table 4 below were dissolved in a solvent, and a solution having a solid content concentration of 5% by mass was prepared for each, and this was filtered through a 0.1 μm polyethylene filter to prepare a resist composition. The prepared resist composition was evaluated by the following method, and the results are shown in Table 4. About each component in a table | surface, ratio when using multiple is mass ratio.
In addition, Example 13 shall be read as “reference example”.

<Evaluation>
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The prepared resist composition was applied thereon and baked at 130 ° C. for 60 seconds to form a 120 nm resist film. The obtained wafer was exposed through a 6% halftone mask having a 65 nm 1: 1 line and space pattern using an ArF excimer laser immersion scanner (PAS5500 / 1250i, NA0.85, manufactured by ASML). Ultra pure water was used as the immersion liquid. Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
[Pattern shape]
The pattern shape was observed with a scanning microscope (Hitachi, Ltd. S-4800).
[Line edge roughness (LER)]
For the range of 5 μm edge in the longitudinal direction of the line pattern, measure the distance from the reference line where the edge should be at 50 points with a length measuring SEM (S-8840, manufactured by Hitachi, Ltd.), calculate the standard deviation, and calculate 3σ did. A smaller value indicates better performance.

[Measurement of receding contact angle]
The prepared positive resist composition was applied on a silicon wafer and baked at 115 ° C. for 60 seconds to form a 200 nm resist film. The receding contact angle of water droplets was measured by the expansion / contraction method of a dynamic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). An initial droplet size of 35 μL was sucked at a rate of 6 μL / sec for 5 seconds, and a value with a stable dynamic contact angle during suction was defined as a receding contact angle. The measurement temperature was 25 ° C.
Separately, a resist composition from which the hydrophobic resin (C) was removed from Table 4 was prepared, and the receding contact angle was measured in the same manner as described above for the resist composition from which the hydrophobic resin (C) was removed.

[Evaluation of acid elution amount]
Each resist composition was applied to an 8-inch silicon wafer and baked at 115 ° C. for 60 seconds to form a 150 nm resist film. After exposing this resist film with an exposure machine having a wavelength of 193 nm at an entire surface of 50 mJ / cm ² , 5 ml of pure water deionized using an ultrapure water production apparatus (Milli-QJr., Manufactured by Nihon Millipore) It was dripped in. Water was placed on the resist film for 50 seconds, the water was collected, and the acid elution concentration was quantified by LC-MS.
LC device: Waters 2695
MS equipment: esquire 3000plus from Bruker Daltonics
The MS detection intensity of ionic species having a mass of 299 (corresponding to nonaflate anion) was measured with the LC-MS apparatus, and the elution amount of nonafluorobutanesulfonic acid was calculated. A smaller value indicates better performance.

  The symbols in the table are as follows.

[Basic compounds]
DIA: 2,6-diisopropylaniline PEA: N-phenyldiethanolamine TOA: trioctylamine PBI: 2-phenylbenzimidazole

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)

〔solvent〕
A1: Propylene glycol monomethyl ether acetate A3: Cyclohexanone B1: Propylene glycol monomethyl ether B2: Ethyl lactate

[Dissolution inhibitor compound]
LCB: t-butyl lithocholic acid

  From the results in Table 4, the resist composition of the present invention has a large receding contact angle of the resist film with respect to the immersion liquid, good pattern shape and line edge roughness, and the amount of acid elution into the immersion liquid is suppressed. I understand that.

Claims (13)

(A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
A resist composition containing (C) a hydrophobic resin and (D) a solvent ,
The hydrophobic resin (C) is a resin having a group represented by the following general formula (F3a), a resin having a group represented by any of the following general formulas (CS-1) to (CS-3), or And a resin having a repeating unit represented by the following general formula (Ia) (however, from a hydrophobic resin (C), a resin having a repeating unit represented by the following general formula (2), and 1,1 , 1,3,3,3-hexafluoro-2-hydroxyisopropyl group ( excluding a resin having —C (CF ₃ ) ₂ OH),
The addition amount of the hydrophobic resin (C) is 0.1 to 10% by mass based on the total solid content of the resist composition,
Sparse receding contact angle of the resist film not containing the aqueous resin (C) is, the resist composition is characterized in that not less than 50 degrees.

In general formula (F3a),
R _62a and R _63a each independently represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R _62a and R _63a may be connected to each other to form a ring.
R _64a represents a hydrogen atom, a fluorine atom or an alkyl group.

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents an alkyl group or a cycloalkyl group.
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group.
n represents an integer of 1 to 5.

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

[In General Formula (2), R ³ represents hydrogen, a methyl group, or a trifluoromethyl group. Each R ⁴ independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms. Further, any two R ⁴ may be bonded to each other to form a divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom to which each R ⁴ is bonded. ] The resist composition according to claim 1 , wherein the hydrophobic resin (C) has a repeating unit of (meth) acrylate having a group represented by the general formula (F3a). (A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a hydrophobic resin and
(D) Solvent
A resist composition comprising:
Hydrophobic resin (C) is, have a repeating unit represented by the repeating unit and the following general formula represented by the following general formula (II) (III),
Receding contact angle of the resist film not containing a hydrophobic resin (C) is characterized with, Relais resist composition be at least 50 degrees.

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
m and n are numbers representing the ratio of repeating units, and 0 <m <100 and 0 <n <100. Resin (A) has a non-acid-decomposable repeating unit represented by the following general formula (I), The resist composition of any one of Claims 1-3 characterized by the above-mentioned.

In general formula (I),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
A represents a single bond or a divalent linking group.
ACG represents a non-acid-eliminable hydrocarbon group. The resist composition according to claim 4 , wherein the non-acid-decomposable repeating unit represented by the general formula (I) is a non-acid-decomposable repeating unit represented by the following general formula (I-1). object.

In general formula (I-1),
Xa ₂ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
Rx ₅ represents an alkyl group or a cycloalkyl group.
n ₃ represents an integer of 4-7.
n ₄ represents an integer of 0 to 3.
When n ₄ is an integer of 2 or more, at least two of Rx ₅ may be bonded to form a ring structure.   (A) a resin whose solubility in an alkaline developer is increased by the action of an acid;
  (B) a compound that generates an acid upon irradiation with actinic rays or radiation,
  (C) a hydrophobic resin and
  (D) Solvent
A resist composition comprising:
  The resin (A) has a non-acid-decomposable repeating unit represented by the following general formula (I ′),
  The resin (A) has a repeating unit having a group having a lactone structure at 10 to 40 mol% in all repeating units of the resin (A),
  The addition amount of the hydrophobic resin (C) is 0.1 to 10% by mass based on the total solid content of the resist composition,
  A resist composition comprising a resist film containing no hydrophobic resin (C) having a receding contact angle of 50 degrees or more.

  In the general formula (I ′),
  Xa ₁ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  A represents a single bond or a divalent linking group.
  ACG 'represents a non-acid-eliminable hydrocarbon group consisting only of carbon atoms and hydrogen atoms.   The non-acid-decomposable repeating unit represented by the general formula (I ') is a non-acid-decomposable repeating unit represented by the following general formula (I'-1). Resist composition.

  In general formula (I′-1),
  Xa ₂ Represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.
  Rx ₅ 'Represents an unsubstituted alkyl group or an unsubstituted cycloalkyl group.
  n ₃ Represents an integer of 4 to 7.
  n ₄ Represents an integer of 0 to 3.
  n ₄ Rx is an integer greater than or equal to 2, Rx ₅ At least two of 'may be bonded to form a ring structure. The resist composition according to claim 6 or 7 , wherein the hydrophobic resin (C) has at least one of a fluorine atom and a silicon atom. Hydrophobic resin (C) is, the resist according to any one of claims 6-8, characterized in that the one resin selected from the following resins (C-1) ~ (C -6) Composition.
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group.
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-3) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group.
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group Having a resin.
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-6) a repeating unit (a) having a fluoroalkyl group, a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl Having a repeating unit (c) having a group or an aryl group. The resist composition according to any one of claims 1 to 9, wherein the receding contact angle of the resist film not containing the hydrophobic resin (C) is 55 degrees or more. Resin (A) has a repeating unit by the (meth) acrylate which has alicyclic structure, and the total content is 40 mol% or more, The any one of Claims 1-10 characterized by the above-mentioned. Resist composition. The resist film formed with the resist composition of any one of Claims 1-11. Immersion exposure resist film of claim 12, a pattern forming method characterized by comprising the step of developing.