JP4991344B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

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

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

  Lithography using an electron beam or EUV light is positioned as a next-generation or next-generation pattern formation technology, and a positive resist with high sensitivity, high resolution, and improved density dependency is desired. Here, the density dependency means a pattern dimension difference between a portion where the resist pattern density is high and a portion where the resist pattern density is low. If this difference is large, the process margin becomes narrow during actual pattern formation. One of the important issues in resist technology development is how to reduce the size. High sensitivity, high resolution, and good density dependence are in a trade-off relationship, and it is very important how to satisfy them simultaneously.

  Furthermore, in lithography using KrF excimer laser light, it is also important to satisfy high sensitivity, high resolution, and good density dependence at the same time, and these solutions are necessary.

  As a resist suitable for the lithography process using KrF excimer laser light, electron beam, or EUV light, a chemically amplified resist utilizing an acid-catalyzed reaction is mainly used from the viewpoint of high sensitivity. In the resist, as a main component, a phenolic polymer (hereinafter abbreviated as a phenolic acid-decomposable resin) having a property that is insoluble or hardly soluble in an antari developer and becomes soluble in an antari developer by the action of an acid, and A chemically amplified resist composition comprising an acid generator is effectively used.

With respect to these positive resists, several resist compositions using a phenolic acid-decomposable resin obtained by copolymerizing an acid-decomposable acrylate monomer having an alicyclic group as an acid-decomposable group have been known. For example, positive resist compositions disclosed in Patent Documents 1 to 5 can be exemplified. Further, Patent Document 6 discloses an example using a low molecular weight phenol compound protected with an acid-decomposable protecting group.
However, in any combination of these, the present situation is that high sensitivity, high resolution, and good density dependence are not satisfied at the same time in the ultrafine region.

US Pat. No. 5,561,194 JP 2001-166474 A JP 2001-166478 A JP 2003-107708 A JP 2001-194792 A JP 2005-326838 A

  The object of the present invention is to solve the problem of performance improvement technology in microfabrication of semiconductor elements using actinic rays or radiation, in particular KrF excimer laser light, electron beam or EUV light, and has high sensitivity and high resolution. It is an object to provide a positive resist composition that simultaneously satisfies the properties and good density dependence, and also has good line width roughness and dissolution contrast, and a pattern forming method using the same.

一般式（Ｉ）に於いて、
Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、各々独立に、水素原子、アルキル基、シクロアルキル基、酸の作用により脱離する基若しくは酸の作用により脱離しない基で保護されていてもよいカルボキシル基又は酸の作用により脱離する基若しくは酸の作用により脱離しない基で保護されていてもよいカルボキシアルキル基を表す。複数のＲ_１は、結合して環を形成してもよい。複数のＲ_２は、結合して環を形成してもよい。複数のＲ_３は、結合して環を形成してもよい。複数のＲ_４は、結合して環を形成してもよい。複数あるＲ_１、Ｒ_２、Ｒ_３及びＲ_４は、互いに同じであっても異なっていてもよい。
Ｒ_５及びＲ_６は、各々独立に、水素原子又は有機基を表す。複数あるＲ_５及びＲ_６は、互いに同じであっても異なっていてもよい。
Ｒ_２とＲ_５は、結合して環を形成してもよい。
Ｒ_４とＲ_６は、結合して環を形成してもよい。
Ｗは、単結合、直鎖若しくは分岐状アルキレン基、シクロアルキレン基、アリーレン基又はこれらの組み合わせから成る基を表す。
但し、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４の内の少なくとも一つは、酸の作用により脱離する基で保護されたカルボキシル基を表すか、又は、ＯＲ_５及びＯＲ_６の内の少なくとも一つは、酸の作用により脱離する基で保護されたフェノール性水酸基を表す。
ｘは、正の整数を表す。
ｙは、０以上の整数を表し、Ｗが単結合の場合、ｙは０である。
ｚは、０以上の整数を表す。
ｖは、０以上の整数を表す。
ｍ１、ｍ３、及びｍ４は、正の整数を表す。
ｍ２及びｍ５は、０以上の整数を表す。
但し、ｍ１＋ｍ２＋ｚ＝５、ｍ３＋ｖ＝３、ｍ４＋ｍ５＝５、ｍ２＋ｍ５≧２を満たす。

一般式（ＩＩ）に於いて、
Ｒ_１１及びＲ_１２は、各々独立に、水素原子、アルキル基、シクロアルキル基、酸の作用により脱離する基若しくは酸の作用により脱離しない基で保護されていてもよいカルボキシル基又は酸の作用により脱離する基若しくは酸の作用により脱離しない基で保護されていてもよいカルボキシアルキル基を表す。複数のＲ_１１は、結合して環を形成してもよい。複数のＲ_１２は、結合して環を形成してもよい。複数あるＲ_１１及びＲ_１２は、互いに同じであっても異なっていてもよい。
Ｒ_１３は、水素原子又は有機基を表す。複数あるＲ_１３は、互いに同じであっても異なっていてもよい。
Ｒ_１１とＲ_１３は、結合して環を形成してもよい。
Ｘは、複数ある場合には各々独立に、単結合又は２価の連結基を表す。
但し、Ｒ_１１及びＲ_１２の内の少なくとも１つは、酸の作用により脱離する基で保護されたカルボキシル基を表すか、又は、ＯＲ_１３は、酸の作用により脱離する基で保護されたフェノール性水酸基を表す。
ａは、１〜４の整数を表す。
ｍ１１は、０以上の整数を表す。
ｍ１２は、０以上の整数を表す。
＜３＞
一般式（Ｉ）に於いて、Ｒ_５及びＲ_６の内の少なくとも１つが、酸の作用により脱離する基であることを特徴とする上記＜２＞に記載のポジ型レジスト組成物。
＜４＞
更に、（Ｃ）酸の作用によりアルカリ現像液への溶解性が増大する樹脂を含有することを特徴とする上記＜１＞〜＜３＞のいずれかに記載のポジ型レジスト組成物。
＜５＞
上記＜１＞〜＜４＞のいずれかに記載のポジ型レジスト組成物により形成された、レジスト膜。
＜６＞
上記＜５＞に記載のレジスト膜を、露光、現像する工程を有することを特徴とするパターン形成方法。
尚、本発明は、上記＜１＞〜＜６＞に係る発明であるが、以下、その他についても参考のため記載した。 The present invention is achieved by the following configurations.
<1>
(A) a compound capable of generating an acid upon irradiation with an actinic ray or radiation, and (B) a carboxyl group protected by a group capable of leaving by the action of an acid and a phenolic hydroxyl group protected by a group capable of leaving by the action of an acid; A group having a molecular weight of 500 to 3,000 having different groups , wherein the carboxyl group is derived from a carboxyl group protected by a group capable of leaving by the action of an acid, and the group leaving by the action of the acid. The compound which produces | generates together the phenolic hydroxyl group derived from the phenolic hydroxyl group protected by (50) is 50 mass% with respect to the solid content whole quantity of a positive resist composition. A positive resist composition characterized in that it is ˜99.5% by mass.
<2>
The positive resist composition as described in <1> above, wherein the compound of component (B) is represented by the following general formula (I) or (II).

In general formula (I),
R ₁ , R ₂ , R ₃ and R ₄ may be each independently protected with a hydrogen atom, an alkyl group, a cycloalkyl group, a group that is released by the action of an acid, or a group that is not released by the action of an acid. It represents a good carboxyl group or a carboxyalkyl group which may be protected by a group capable of leaving by the action of an acid or a group not leaving by the action of an acid. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same as or different from each other.
R ₅ and R ₆ each independently represents a hydrogen atom or an organic group. A plurality of R ₅ and R ₆ may be the same as or different from each other.
R ₂ and R ₅ may combine to form a ring.
R ₄ and R ₆ may combine to form a ring.
W represents a group consisting of a single bond, a linear or branched alkylene group, a cycloalkylene group, an arylene group, or a combination thereof.
Provided that at least one of R ₁ , R ₂ , R ₃ and R ₄ represents a carboxyl group protected by a group capable of leaving by the action of an acid, or at least one of OR ₅ and OR _6. One represents a phenolic hydroxyl group protected with a group capable of leaving by the action of an acid.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 represent a positive integer.
m2 and m5 represent an integer of 0 or more.
However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2.

In general formula (II):
R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, a group that is eliminated by the action of an acid, or a group that is not removed by the action of an acid, or a carboxyl group or an acid A carboxyalkyl group which may be protected by a group capable of leaving by action or a group not leaving by the action of an acid. A plurality of R ₁₁ may combine to form a ring. A plurality of R ₁₂ may combine to form a ring. A plurality of R ₁₁ and R ₁₂ may be the same as or different from each other.
R ₁₃ represents a hydrogen atom or an organic group. A plurality of R ₁₃ may be the same as or different from each other.
R ₁₁ and R ₁₃ may combine to form a ring.
When there are a plurality of Xs, each independently represents a single bond or a divalent linking group.
However, at least one of R ₁₁ and R ₁₂ represents a carboxyl group protected by a group capable of leaving by the action of an acid, or OR ₁₃ is protected by a group capable of leaving by the action of an acid. Represents a phenolic hydroxyl group.
a represents an integer of 1 to 4.
m11 represents an integer of 0 or more.
m12 represents an integer of 0 or more.
<3>
In the general formula (I), at least one of R ₅ and R ₆ is a group capable of leaving by the action of an acid, and the positive resist composition as described in <2> above.
<4>
The positive resist composition as described in any one of <1> to <3>, further comprising (C) a resin whose solubility in an alkaline developer is increased by the action of an acid.
<5>
A resist film formed of the positive resist composition according to any one of <1> to <4> above.
<6>
A pattern forming method comprising a step of exposing and developing the resist film according to <5>.
In addition, although this invention is invention which concerns on said <1>-<6>, hereafter, it described for reference also about others.

  (1) (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (B) a phenol protected with a carboxyl group protected by a group capable of leaving by the action of an acid and a group capable of leaving by the action of an acid. A positive resist composition comprising a compound having a molecular weight of 500 to 3,000 having a functional hydroxyl group.

  (2) The positive resist composition as described in (1), wherein the compound of component (B) is represented by the following general formula (I) or (II).

In general formula (I),
R ₁ , R ₂ , R ₃ and R ₄ may each independently be protected with a hydrogen atom, an alkyl group, a cycloalkyl group, a group leaving by the action of an acid, or a group not leaving by the action of an acid. It represents a good carboxyl group or a carboxyalkyl group which may be protected by a group capable of leaving by the action of an acid or a group not leaving by the action of an acid. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different from each other.
R ₅ and R ₆ each independently represents a hydrogen atom or an organic group. A plurality of R ₅ and R ₆ may be the same or different from each other.
R ₂ and R ₅ may combine to form a ring.
R ₄ and R ₆ may combine to form a ring.
When there are a plurality of Ws, each independently represents a group consisting of a single bond, a linear or branched alkylene group, a cycloalkylene group, an arylene group, or a combination thereof.
However, at least one of R ₁ , R ₂ , R ₃ , R ₄ , OR ₅ and OR ₆ is a carboxyl group protected by a group capable of leaving by the action of an acid or a group leaving by the action of an acid. Represents a phenolic hydroxyl group protected with.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 represent a positive integer.
m2 and m5 represent an integer of 0 or more.
However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2.

In general formula (II):
R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, a group capable of leaving by the action of an acid, or a carboxyl group or an acid which may be protected by a group not leaving by the action of an acid. A carboxyalkyl group which may be protected by a group capable of leaving by action or a group not leaving by the action of an acid. A plurality of R ₁₁ may combine to form a ring. A plurality of R ₁₂ may combine to form a ring. A plurality of R ₁₁ and R ₁₂ may be the same as or different from each other.
R ₁₃ represents a hydrogen atom or an organic group. A plurality of R ₁₃ may be the same as or different from each other.
R ₁₁ and R ₁₃ may combine to form a ring.
When there are a plurality of Xs, each independently represents a single bond or a divalent linking group.
However, at least one of R ₁₁ , R ₁₂ and OR ₁₃ represents a carboxyl group protected by a group capable of leaving by the action of an acid or a phenolic hydroxyl group protected by a group capable of leaving by the action of an acid. .
a represents an integer of 1 to 4.
m11 represents an integer of 0 or more.
m12 represents an integer of 0 or more.

(3) The positive resist composition as described in (1), wherein in general formula (I), at least one of R ₅ and R ₆ is a group capable of leaving by the action of an acid. .

(4) The positive resist composition as described in any one of (1) to (3), further comprising (C) a resin whose solubility in an alkaline developer is increased by the action of an acid.

  (5) A pattern forming method comprising a step of forming a resist film with the positive resist composition according to any one of (1) to (4), exposing and developing the resist film.

  According to the present invention, high sensitivity, high resolution, and good density dependence are simultaneously satisfied in microfabrication of semiconductor elements using actinic rays or radiation, particularly KrF excimer laser light, electron beam or EUV light. Further, it is possible to provide a positive resist composition having good line width roughness and dissolution contrast and a pattern forming method using the same.

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 has a substituent with what does not have 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).

(B) A compound having a molecular weight of 500 to 3000 having a carboxyl group protected by a group capable of leaving by the action of an acid and a phenolic hydroxyl group protected by a group capable of leaving by the action of an acid. Contains a compound having a molecular weight of 500 to 3000 having a carboxyl group protected by a group capable of leaving by the action of an acid and a phenolic hydroxyl group protected by a group capable of leaving by the action of an acid.
The compound of component (B) is preferably represented by the following general formula (I) or (II).

In general formula (I),
R ₁ , R ₂ , R ₃ and R ₄ may each independently be protected with a hydrogen atom, an alkyl group, a cycloalkyl group, a group leaving by the action of an acid, or a group not leaving by the action of an acid. It represents a good carboxyl group or a carboxyalkyl group which may be protected by a group capable of leaving by the action of an acid or a group not leaving by the action of an acid. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different from each other.
R ₅ and R ₆ each independently represents a hydrogen atom or an organic group. A plurality of R ₅ and R ₆ may be the same or different from each other.
R ₂ and R ₅ may combine to form a ring.
R ₄ and R ₆ may combine to form a ring.
W represents a group consisting of a single bond, a linear or branched alkylene group, a cycloalkylene group, an arylene group, or a combination thereof.
However, at least one of R ₁ , R ₂ , R ₃ , R ₄ , OR ₅ and OR ₆ is a carboxyl group protected by a group capable of leaving by the action of an acid or a group leaving by the action of an acid. Represents a phenolic hydroxyl group protected with.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 represent a positive integer.
m2 and m5 represent an integer of 0 or more.
However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2.

In general formula (II):
R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, a group capable of leaving by the action of an acid, or a carboxyl group or an acid which may be protected by a group not leaving by the action of an acid. A carboxyalkyl group which may be protected by a group capable of leaving by action or a group not leaving by the action of an acid. A plurality of R ₁₁ may combine to form a ring. A plurality of R ₁₂ may combine to form a ring. A plurality of R ₁₁ and R ₁₂ may be the same as or different from each other.
R ₁₃ represents a hydrogen atom or an organic group. A plurality of R ₁₃ may be the same as or different from each other.
R ₁₁ and R ₁₃ may combine to form a ring.
When there are a plurality of Xs, each independently represents a single bond or a divalent linking group.
However, at least one of R ₁₁ , R ₁₂ and OR ₁₃ represents a carboxyl group protected by a group capable of leaving by the action of an acid or a phenolic hydroxyl group protected by a group capable of leaving by the action of an acid. .
a represents an integer of 1 to 4.
m11 represents an integer of 0 or more.
m12 represents an integer of 0 or more.

In the general formula (I), the alkyl group in R ₁ , R ₂ , R ₃ and R ₄ may be linear or branched, preferably a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, The thing of 1-10 carbon atoms, such as a hexyl group and an octyl group, is mentioned.
The cycloalkyl group in R ₁ , R ₂ , R ₃ and R ₄ may be monocyclic or polycyclic. Examples thereof include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The number of carbon atoms is preferably 6 to 30, and particularly preferably 7 to 25. For example, an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group Cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, cyclododecanyl group and the like.
The alkyl group and cycloalkyl group may have a substituent. Examples of the substituent that the alkyl group and cycloalkyl group may have include a hydroxyl group, a carboxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkoxy group (methoxy group, ethoxy group, propoxy group, Butoxy group, etc.).

R ₁ , R ₂ , R ₃ and R ₄ may be protected by a group capable of leaving by the action of an acid, or a group capable of leaving by the action of an acid in a carboxyl group or a carboxyalkyl group ( Hereinafter, the “acid-leaving group” is a group that is eliminated by the action of an acid generated by exposure to generate a carboxylic acid derived from an ester group.
Specific examples include tertiary alkyl groups such as t-butyl group and t-amyl group.

  The acid leaving group may be a bridged alicyclic group, more preferably a group represented by the following general formula (pI) to general formula (pVI).

In the general formulas (pI) to (pVI),
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.
Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. However, at least one of R _{12 to} R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group. However, at least one of R _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group. However, at least one of R _{22 to} R ₂₅ represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

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

The alicyclic hydrocarbon group in R _{12 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.

  Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

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

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

R ₁ , R ₂ , R ₃ and R ₄ may be protected by a group that does not leave under the action of an acid, and a group that does not leave under the action of an acid in a carboxyl group or a carboxyalkyl group; Is an organic group that does not leave by the action of an acid generated by exposure, for example, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group that does not leave by the action of an acid, An alkoxycarbonyl group, an amide group, a cyano group, etc. can be mentioned. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, and an octyl group. be able to. The cycloalkyl group is preferably a cycloalkyl group having 3 to 10 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and an adamantyl group. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthracenyl group. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a cumyl group. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, and an isobutoxy group.

Examples of the organic group in R ₅ and R ₆ include a group capable of leaving by the action of an acid and a group not leaving by the action of an acid.

Examples of the group leaving by the action of an acid in R ₅ and R ₆ include, for example, —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ) and the like can be mentioned.
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.

In R ₅ and R ₆ , the group that does not leave by the action of an acid is an organic group that does not leave by the action of an acid. For example, an alkyl group or aryl that does not leave by the action of an acid Groups, aralkyl groups, alkoxy groups, alkoxycarbonyl groups, amide groups, cyano groups and the like. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group. For example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl Group, cyclopropyl group, cyclobutyl group, cyclohexyl group, adamantyl group and the like. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthracenyl group. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a cumyl group. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, and an isobutoxy group.

The alkylene group in W may be linear or branched and preferably has 1 to 10 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group.
The cycloalkylene group in W may be monocyclic or polycyclic, and examples of the alkylene group forming the ring include a cycloalkylene group having 3 to 8 carbon atoms (for example, a cyclopentylene group and a cyclohexylene group). be able to.
Each of the above groups may further have a substituent, and as the substituent, an alkyl group (preferably having a carbon number of 1 to 10, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, Isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc.), alkoxy group (preferably having 1 to 4 carbon atoms such as methoxy group, ethoxy group) , Propoxy group, butoxy group, etc.), fluorine atom, chlorine atom, bromine atom, iodine atom and the like.
An alkylene chain or a cycloalkylene chain includes —O—, —OC (═O) —, —OC (═O) O—, —N (R) —C (═O) —, —N (R ) -C (= O) O-, -S-, -SO-, -SO ₂ -may be included. Here, R represents a hydrogen atom or an alkyl group (preferably having a carbon number of 1 to 10, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group). Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like.
The arylene group in W is preferably an arylene group having 6 to 15 carbon atoms such as a phenylene group, a tolylene group and a naphthylene group.

R ₁₁ and R ₁₂ in the general formula (II) are the same as R ₁ , R ₂ , R ₃ and R _{4 in} the general formula (I).
R ₁₃ is the same as R ₅ and R _{6 in} formula (I).

As the divalent linking group for X, a linear or branched alkylene group having 1 to 20 carbon atoms,
Examples thereof include a cycloalkylene group, an arylene group, and an aralkylene group, and a hetero atom may be interposed in the middle. Especially, a C1-C20 linear or branched alkylene group, a cycloalkylene group, and an arylene group are preferable, and a C1-C4 linear or branched alkyl group is especially preferable.

  (B) As a compound of a component, the compound represented by either of the following general formula (III)-(V) can be mentioned further.

In general formulas (III) to (V),
R ₁ , R ₂ , R ₅ , x, z, m1 and m2 have the same meaning as those in formula (I).
R ₇ represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₇ may combine to form a ring. A plurality of R ₇ may be the same as or different from each other.
u represents a positive integer. However, u + x = 3.
r represents a positive integer.
W ₀ represents an arylene group.
W ₁ represents a single bond, an alkylene group or a cycloalkylene group.
A represents the following structure.

Where
R ₃ , R ₄ , R ₆ , m4 and m5 are as defined in general formula (I).

Specific examples of the compound (B) are shown below, but the present invention is not limited to these.
In a specific example, when there are a plurality of R, each independently represents a hydrogen atom, a group capable of leaving by the action of an acid or a group not leaving by the action of an acid, and Ra is a group having a plurality of Rs. Each independently represents a hydrogen atom, a group capable of leaving by the action of an acid, or a group not leaving by the action of an acid.

In the above specific examples, the group capable of leaving by the action of an acid includes —C (R _11a ) (R _12a ) (R _13a ), —C (R _14a ) (R _15a ) (OR _16a ), —CO —OC (R _11a ) (R _12a ) (R _13a ) is preferred. Here, R _<11a > -R <_13a> represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, or an aryl group each independently. R _14a and R _15a each independently represents a hydrogen atom or an alkyl group. R _16a represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group. Two of R _11a , R _12a and R _13a , or two of R _14a , R _15a and R _16a may be bonded to form a ring.

  Hereinafter, specific examples of the group capable of leaving by the action of an acid will be given, but the present invention is not limited thereto.

It is preferable that the compound of (B) component has an alkali-soluble group.
Examples of the alkali-soluble group include a phenolic hydroxyl group, a carboxyl group, a sulfonic acid group, and a hexafluoroisopropanol group [—C (CF ₃ ) ₂ OH]. Preferred are a phenolic hydroxyl group, a carboxyl group, and a hexafluoroisopropanol group, and more preferred are a phenolic hydroxyl group and a carboxyl group.

The compound of the component (B) preferably has 1 to 10 phenolic hydroxyl groups, and more preferably 2 to 6 phenolic hydroxyl groups.
The compound of component (B) preferably has 1 to 10 phenolic hydroxyl groups protected with a group capable of leaving by the action of an acid, more preferably 2 to 8.
The compound of component (B) preferably has 1 to 6 carboxyl groups protected by a group capable of leaving by the action of an acid, and more preferably has 2 to 4 carboxyl groups.
The compound of component (B) may have 1 to 2 carboxyl groups protected with a group that does not leave by the action of an acid.

In order to synthesize the compound of component (B), for example, a polycyclic compound having a phenolic hydroxyl group and a carboxylic acid ester group by reacting a ketone compound having a phenolic hydroxyl group with a carboxylic acid ester compound having a phenolic hydroxyl group. After synthesizing, a group capable of leaving by the action of an acid is introduced into the resulting polycyclic compound to form an acid-decomposable group (a group that decomposes by the action of an acid and increases the solubility in an alkali developer). You can do it.
In the case of R ₅ or R _{6 in} the general formula (I), for example, a group having an acid-decomposable group can be introduced by modification as follows.
-[C ( _R17a ) ( _R18a )] _p- CO-OC ( _R11a ) ( _R12a ) ( _R13a )
Here, R _17a and R _18a each independently represent a hydrogen atom or an alkyl group. Moreover, p is an integer of 1-4.

  The content of the component (B) compound is usually 50% by mass to 99.5% by mass, preferably 60% by mass to 99.0% by mass with respect to the total solid content of the positive resist composition. Preferably it is 70 mass%-98.0 mass%.

  A resin (polymer) may be further added to the positive resist composition of the present invention. The resin to be added is an alkali-soluble resin having no acid-decomposable group, or a resin whose solubility in an alkali developer is increased by the action of an acid (also referred to as “acid-decomposable resin”). Alkali-soluble resins include p-hydroxystyrene homopolymers or copolymers, (meth) acrylic acid homopolymers or copolymers, p- (1,1,1,3,3,3-hexafluoro 2-Hydroxypropyl) styrene homopolymer or copolymer. Examples of the acid-decomposable resin include resins in which the alkali-soluble group of the alkali-soluble resin is protected with an acid-eliminable group. The acid-decomposable resin will be described later.

  Content of resin to add is 1-50 mass% normally with respect to the solid content whole quantity of a positive resist composition, Preferably it is 5-40 mass%, More preferably, it is 10-30 mass%.

(A) Compound that generates acid upon irradiation with actinic ray or radiation
The compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter sometimes referred to as “acid generator”) used in the positive resist composition of the present invention will be described below.
The acid generator used in the present invention can be selected from compounds generally used as an acid generator.
That is, it generates an acid upon irradiation with actinic rays or radiation used for photoinitiators of photocationic polymerization, photoinitiators of photoradical polymerization, photodecolorants of dyes, photochromic agents, or microresists. Known compounds 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 the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.

The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include 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.

Compound (Z1-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

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

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

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

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

  The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (for example, having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), an aryl group (for example, having 6 to 6 carbon atoms). 14), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group or the like may be used as a substituent. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl having 1 to 4 carbon atoms. Group, 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.

Examples of the non-nucleophilic anion as X ⁻ 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.

Examples of the aliphatic group in the aliphatic sulfonate anion include, for example, an alkyl group having 1 to 30 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec- Butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl And an eicosyl group and a cycloalkyl group having 3 to 30 carbon atoms, specifically, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a 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 such substituents include nitro groups, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), carboxyl groups, hydroxyl groups, amino groups, cyano groups, and alkoxy groups (preferably having 1 to 5 carbon atoms). ), A cycloalkyl group (preferably 3 to 15 carbon atoms), an aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group (preferably 2 to 12 carbon atoms). ), An alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 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 group in the aliphatic carboxylate anion include those similar to the aliphatic group in the aliphatic sulfonate anion.

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

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

  The aliphatic group, aromatic group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent include aliphatic sulfonic acid The same halogen atom, alkyl group, cycloalkyl group, alkoxy group, alkylthio group and the like as in the anion can be exemplified.

  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. These alkyl groups may have a substituent, and examples of the substituent include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, and the like, which are substituted with a fluorine atom. Alkyl groups are preferred.

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

Examples of the non-nucleophilic anion of X ⁻ 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 particularly preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, an aromatic sulfonic acid anion having a fluorine atom, most preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

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

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, most preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R _{201 to} R ₂₀₃ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. Butyl group, pentyl group and the like. More preferable examples of the alkyl group include a 2-linear or branched oxoalkyl group and an alkoxycarbonylmethyl group.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

  The 2-oxoalkyl group may be linear, branched or cyclic, and preferably includes a group having> C = O at the 2-position of the above alkyl group or 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.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} the general formula (ZI).

The alkyl group as R _{1c to} R _7c is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, A linear or branched pentyl group can be exemplified.

The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group and a cyclohexyl group.

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

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

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl groups and cycloalkyl groups as R _{1c to} R _{7c, such} as a 2-oxoalkyl group and a 2-oxocycloalkyl group. An alkoxycarbonylmethyl group is more preferable.

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 R _{1c to} R _5c .

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

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

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group.
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

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

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

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₆ , R ₂₀₇ and R ₂₀₈ are an alkyl group, a cycloalkyl group or an aryl group, and these are the same as the alkyl group, cycloalkyl group or aryl group as R _{204 to} R ₂₀₇ .
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.

  The acid generator in the present invention particularly preferably has an anion structure containing an alkyl group having 4 or less carbon atoms substituted with a fluorine atom, or an aromatic group substituted with a fluorine atom, and a triarylsulfonium cation structure. It is an acid generator. Such acid generators are preferably those represented by the following general formulas (I) to (III).

In general formulas (I) to (III),
R ₁ represents an alkyl group, an alicyclic hydrocarbon group, a hydroxyl group, a carboxyl group, an alkoxy group or a halogen atom.
y represents 0 or an integer of 1 to 5. When y is an integer of 2 or more, two or more R _{1 s} may be the same or different.
Q _{1 to} Q ₄ are each independently an alkyl group having 1 to 3 carbon atoms substituted with a fluorine atom, a cycloalkyl group substituted with a fluorine atom, an aryl group substituted with a fluorine atom, or a fluorinated alkyl group. Represents a substituted aryl group.

As the alkyl group for R ₁ , a linear or branched alkyl group having 1 to 15 carbon atoms is preferable,
For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, and the like can be given.
Examples of the alicyclic hydrocarbon group for R ₁ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
Examples of the alkyl group substituted with a fluorine atom of Q _{1 to} Q ₄ include —CF ₃ , —C ₂ F _{5.
, -N-C 3 F 7,} -CF (CF 3) 2, -CH (CF 3) 2, - (CF 2) 2 OCF 2 CF 3, -
(CF ₂ ) ₂ O (CH ₂ ) ₃ CH ₃ , — (CF ₂ ) ₂ O (CH ₂ ) ₁₃ CH ₃ , — (CF ₂ ) ₂ O (C
F ₂ ) ₂ (CH ₂ ) ₃ CH _{3 and the} like.
Examples of the aryl group substituted with a fluorine atom of Q _{1 to} Q ₄ include 2,3,4,5,6-pentafluorophenyl group, 2,3,4-trifluorophenyl group, and 2,4-difluoro. A phenyl group, 4-fluorophenyl group, 4-undecanyloxy-2,3,5,6-tetrafluorophenyl group and the like can be mentioned.
Examples of the aryl group substituted with a fluorinated alkyl group of Q _{1 to} Q ₄ include a 3-trifluoromethylphenyl group, a 3,5-bis (trifluoromethyl) phenyl group, a 4-trifluoromethylphenyl group, And 4-n-nonafluorobutylphenyl group.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, examples of particularly preferable compounds are listed below, but the present invention is not limited thereto.

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

  The positive resist composition of the present invention preferably contains, as an acid generator, a compound that generates sulfonic acid upon irradiation with actinic rays or radiation (hereinafter also referred to as “sulfonic acid generator”).

  The positive resist composition of the present invention more preferably contains a compound that generates carboxylic acid upon irradiation with actinic rays or radiation (hereinafter also referred to as “carboxylic acid generator”) together with a sulfonic acid generator. As the carboxylic acid generator, a compound represented by the following general formula (C) is preferable.

In the general formula (C), R _{21 to} R ₂₃ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, and R ₂₄ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or Represents an aryl group, and Z represents a sulfur atom or an iodine atom. When Z is a sulfur atom, p is 1, and when Z is an iodine atom, p is 0.

In General Formula (C), R _{21 to} R ₂₃ are preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or 6 to 24 carbon atoms. More preferably, it is an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 15 carbon atoms. It is.
The alkyl group, cycloalkyl group, alkenyl group, and aryl group in R _{21 to} R ₂₃ may have a substituent.
Examples of the substituent that the alkyl group, cycloalkyl group, and alkenyl group may have include a halogen atom (chlorine atom, bromine atom, fluorine atom, etc.), aryl group (phenyl group, naphthyl group, etc.), hydroxy group, An alkoxy group (methoxy group, ethoxy group, butoxy group, etc.) etc. can be mentioned.
Examples of the substituent that the aryl group may have include a halogen atom (chlorine atom, bromine atom, fluorine atom, etc.), nitro group, cyano group, alkyl group (methyl group, ethyl group, t-butyl group, t -Amyl group, octyl group, etc.), hydroxy group, alkoxy group (methoxy group, ethoxy group, butoxy group, etc.) and the like.

R ₂₄ is preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 24 carbon atoms, and more Preferably, they are a C1-C18 alkyl group, a C3-C18 cycloalkyl group, and a C6-C18 aryl group, Most preferably, a C1-C12 alkyl group, C3-C3 A cycloalkyl group having 12 carbon atoms and an aryl group having 6 to 15 carbon atoms. These groups may have a substituent.
Examples of the substituent that the alkyl group, cycloalkyl group, and alkenyl group may have are the same as those described as examples of the substituent when R ₂₁ is an alkyl group. Examples of the substituent for the aryl group, the R ₂₁ may be the same as those mentioned as examples of the substituent when it is an aryl group.

  In addition, the cation structure which has two or more of the cation part of general formula (C) couple | bonded by the single bond or the coupling group (for example, -S-, -O- etc.), and has multiple cation parts of general formula (C). May be formed.

  Although the preferable specific example of the compound which generate | occur | produces carboxylic acid by irradiation of actinic light or a radiation below is given, of course, it is not limited to these.

The content of the carboxylic acid generator in the positive resist composition of the present invention is preferably 0.01 to 10% by mass, more preferably 0.03 to 5% by mass, based on the total solid content of the composition. Particularly preferably, the content is 0.05 to 3% by mass. In addition, these compounds that generate a carboxylic acid upon irradiation with actinic rays or radiation may be used alone or in combination of two or more.
The carboxylic acid generator / sulfonic acid generator (mass ratio) is usually 99.9 / 0.1 to 50/50, preferably 99/1 to 60/40, and particularly preferably 98/2 to 70/30. .
The carboxylic acid generator can be synthesized by a known method such as the synthesis method described in JP-A-2002-27806.

(C) Resin whose solubility in an alkaline developer is increased by the action of an acid In the present invention, (C) a resin whose solubility in an alkali developer is increased by the action of an acid (hereinafter referred to as “resin (C)” From the viewpoint of improving performance such as resolving power and improving storage stability. Examples of the resin whose solubility in an alkaline developer is increased by the action of an acid include a resin having a repeating unit represented by the following general formula (1) or (2).

In general formulas (1) and (2),
R ₁ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoro group having 1 to 4 carbon atoms.
X represents an acid leaving group.
When there are a plurality of R _{3 s} , each independently represents a hydrogen atom, an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
A ₁ represents a group containing a hydrogen atom, a group capable of leaving by the action of an acid, or a group decomposing by the action of an acid, when there are a plurality of A ₁ .
m represents an integer of 1 to 3.
n represents an integer of 0 to 4.

In the general formula (1), R ₁ is preferably a hydrogen atom, a methyl group, or a C _m F _{2m + 1} group (m represents an integer of 1 to 4, preferably 1), particularly preferably. Is a hydrogen atom or a methyl group.

In general formula (1), the acid-eliminable group as X is the same as the acid-eliminable group in compound (B), general formula (I), R _{1 to} R ₄ Is mentioned.

  Hereinafter, although the specific example of the monomer corresponding to the repeating unit shown by General formula (1) is shown, this invention is not limited to this.

In the general formula (2), the alkyl group as R ₃ may have a substituent, for example, an alkyl group having 1 to 8 carbon atoms, specifically a methyl group or an ethyl group. Propyl group, n-butyl group, sec-butyl group, hexyl group and octyl group can be preferably mentioned.
The alkoxy group as R ₃ may have a substituent, for example, the above alkoxy group having 1 to 8 carbon atoms, for example, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy Group, cyclohexyloxy group and the like.
The aryl group as R ₃ may have a substituent, for example, an aryl group having 6 to 15 carbon atoms, and specifically includes a phenyl group, a tolyl group, a naphthyl group, an anthryl group, and the like. Preferable examples can be given.
The acyl group as R ₃ may have a substituent, for example, an acyl group having 2 to 8 carbon atoms, specifically, formyl group, acetyl group, propanoyl group, butanoyl group, pivaloyl Preferred examples include groups and benzoyl groups.
The substituents that these groups may have include hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group) Etc.).

In the general formula (2), the OA ₁ group may be in any position on the benzene ring, but is preferably the meta position or the para position of the styrene skeleton, and particularly preferably the para position.
As the group capable of leaving by the action of an acid in A ₁ , the same compounds as the acid leaving group in the compound (B), general formula (I), and R _{5 to} R ₆ can be exemplified. be able to.

  Although the specific example of the repeating unit represented by General formula (2) below is given, this invention is not limited to these.

  The resin having a repeating unit represented by the general formula (1) or (2) preferably further has a repeating unit represented by the following general formula (3).

In general formula (3),
R ₁ has the same meaning as R ₁ in the general formula (2).
R ₃ represents a monovalent organic group, a halogen atom or a nitro group that is not decomposed by the action of an acid.
p represents an integer of 0 to 5. When p is 2 or more, the plurality of R _{3 s} may be the same or different.

Specific examples of monovalent organic groups (also referred to as acid stabilizing groups) that are not decomposed by the action of an acid of R ₃ include alkyl groups, cycloalkyl groups, aryl groups, and alkoxy groups (however, —O-tertiary alkyl). ), Cycloalkyloxy group, acyl group, alkenyl group, alkenyloxy group, aryloxy group, alkylcarbonyloxy group, alkylamidomethyloxy group, alkylamido group, arylamidomethyl group, arylamido group, etc. . The acid stabilizing group is preferably an alkyl group, an alkoxy group, an alkylcarbonyloxy group, a cycloalkyloxy group, an aryloxy group, an alkylamidooxy group, or an alkylamido group, more preferably an alkyl group, an alkoxy group, An alkylcarbonyloxy group;
R ₃ may be in any position on the benzene ring, but is preferably a meta position or a para position of the styrene skeleton, and particularly preferably a para position.

  Although the specific example of the repeating unit represented by General formula (3) below is given, this invention is not limited to these.

The content of the repeating unit represented by the general formula (1) in the resin (C) is preferably 3 to 80 mol%, more preferably 5 to 70 mol%, and particularly preferably 5 in all repeating units. ˜50 mol%. 3 mol% or more is preferable in order to surely prevent a reduction in film thickness or a decrease in resolving power in the unexposed area, and 80 mol% or less is preferable in terms of adhesion to the substrate and scum suppression.
The content of the repeating unit represented by the general formula (2) in the resin (C) is preferably 20 to 97 mol%, more preferably 30 to 95 mol%, and particularly preferably 50% in all repeating units. -95 mol%. 20% or more is preferable from the viewpoint of poor adhesion to the substrate and suppression of scum, and 97 mol% or less is preferable from the viewpoint of surely preventing a reduction in film thickness and a decrease in resolving power at unexposed portions.

  The resin (C) may have a repeating unit represented by the general formula (3), which is preferable from the viewpoint of improving the film quality and suppressing the decrease in the film thickness of the unexposed area. The content of the repeating unit represented by the general formula (3) is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, and particularly preferably 0 to 40 mol% in each of all the repeating units. 30 mol%.

Resin (C) is copolymerized with other polymerizable monomers suitable so that alkali-soluble groups such as phenolic hydroxyl groups and carboxyl groups can be introduced in order to maintain good developability with respect to an alkaline developer. In order to improve the film quality, other hydrophobic polymerizable monomers such as alkyl acrylate and alkyl methacrylate may be copolymerized.
Furthermore, the resin (C) may contain a monomer having another acid-decomposable group in addition to the acid-decomposable group contained in the general formula (1) or (2). as, for example, it may include those represented by _{-C (= O) -X 1 -R} 0.
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or -NHSO ₂
NH- is represented.

The weight average molecular weight (Mw) of the resin (C) is preferably in the range of 1,000 to 200,000, more preferably in the range of 1,500 to 100,000, and particularly preferably 2,000. It is in the range of ~ 50,000. It is preferably 1,000 or more from the viewpoint of preventing the unexposed portion from being reduced in film thickness, and is preferably 200,000 or less from the viewpoint of slowing the dissolution rate of the resin itself in the alkali and reducing the sensitivity. The dispersity (Mw / Mn) is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.5.
Here, the weight average molecular weight is defined by a polystyrene conversion value of gel permeation chromatography.

  Specific examples of the resin whose solubility in an alkaline developer is increased by the action of an acid are shown below, but the present invention is not limited to this.

Organic Basic Compound In the present invention, it is preferable to use an organic basic compound from the viewpoint of improving performance such as resolution and improving storage stability. As the organic basic compound, a compound containing a nitrogen atom (nitrogen-containing basic compound) is more preferable.
In the present invention, a preferable organic basic compound is a compound having a stronger basicity than phenol.
As a preferable chemical environment, the following general formulas (A) to (E) can be exemplified.
The general formulas (B) to (E) may be part of a ring structure.

In general formula (A),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and each represents a hydrogen atom, an alkyl or cycloalkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, R ²⁰¹ and R ²⁰² may combine with each other to form a ring.
The alkyl group, cycloalkyl group and aryl group as R ²⁰⁰ , R ²⁰¹ and R ²⁰² may have a substituent. As the alkyl group and cycloalkyl group having a substituent, an aminoalkyl group having 1 to 20 carbon atoms and an aminocycloalkyl group, and a hydroxyalkyl group having 1 to 20 carbon atoms are preferable.
In general formula (E),
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms and a cycloalkyl group.

  Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.

Preferred examples include guanidine, aminopyridine, aminoalkylpyridine, aminopyrrolidine, indazole, imidazole, pyrazole, pyrazine, pyrimidine, purine, imidazoline, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and the like. Preferred substituents that these may have include an amino group,
Alkylamino group, aminoaryl group, arylamino group, alkyl group (as substituted alkyl group, especially aminoalkyl group), alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group, etc. Is mentioned.

Particularly preferred compounds include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4 , 5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (Aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4- Aminoethylpyridine, 3-aminopyrrolidine, Perazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methylpyrazine, Examples include, but are not limited to, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine. It is not a thing.
These nitrogen-containing basic compounds are used alone or in combination of two or more.

  A tetraalkylammonium salt type nitrogen-containing basic compound can also be used. Of these, tetraalkylammonium hydroxide having 1 to 8 carbon atoms (tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra- (n-butyl) ammonium hydroxide, etc.) is particularly preferable. These nitrogen-containing basic compounds are used alone or in combination of two or more.

  The use ratio of the acid generator and the organic basic compound in the composition is preferably (total amount of acid generator) / (organic basic compound) (molar ratio) = 2.5 to 300. By setting the molar ratio to 2.5 or more, high sensitivity is obtained, and by setting the molar ratio to 300 or less, it is possible to suppress the resist pattern from becoming thicker over time until post-exposure heat treatment and improve resolution. . (Total amount of acid generator) / (organic basic compound) (molar ratio) is preferably 5.0 to 200, more preferably 7.0 to 150.

Surfactants In the present invention, surfactants can be used, which are preferable from the viewpoints of film forming properties, pattern adhesion, development defect reduction, and the like.

  Specific examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene Polyoxyethylene alkyl allyl ethers such as nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Sorbitan fatty acid esters such as rate, polyoxyethylene sorbitan monolaurate, polyoxyethylene Sorbitan mono palmitate - door,

Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, F-top EF301, EF303, EF352 (Shin-Akita Kasei) (Made by Co., Ltd.), MegaFuck F171, F173 (Dainippon Ink Chemical Co., Ltd.), Florad FC430, FC431 (Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102 , SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), Troysol S-366 (manufactured by Troy Chemical Co., Ltd.), silicon surfactants, organosiloxane polymer KP341 Shin-Etsu Chemical Co., Ltd.) and acrylic or methacrylic acid-based (co) polymer Polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.). The compounding amount of these surfactants is usually 2 parts by mass or less, preferably 1 part by mass or less per 100 parts by mass of the solid content in the composition of the present invention.
These surfactants may be added alone or in some combination.

As the surfactant, any one of fluorine-based and / or silicon-based surfactants (fluorine-based surfactant and silicon-based surfactant, surfactant containing both fluorine atom and silicon atom), or two kinds of surfactants It is preferable to contain the above.
As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, 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 linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).
Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive resist composition (excluding the solvent).

Other Components The positive resist composition of the present invention can further contain a dye, a photobase generator and the like, if necessary.

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

2. Photobase generator As photobase generators that can be added to the composition of the present invention, JP-A-4-151156, JP-A-4-162040, JP-A-5-197148, JP-A-5-5995, JP-A-6-194835, Examples thereof include compounds described in JP-A-8-146608, JP-A-10-83079 and European Patent No. 622682, specifically, 2-nitrobenzylcarbamate, 2,5-dinitrobenzylcyclohexylcarbamate, N-cyclohexyl-4- Methylphenylsulfonamide, 1,1-dimethyl-2-phenylethyl-N-isopropylcarbamate and the like can be suitably used. These photobase generators are added for the purpose of improving the resist shape and the like.

3. Solvents The positive resist composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. The solid content concentration of all resist components is usually preferably 2 to 30% by mass, more preferably 3 to 25% by mass.
Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. Or mixed to use.

  The positive resist composition of the present invention is applied onto a substrate to form a thin film. The thickness of this coating film is preferably 0.05 to 4.0 μm.

  In the present invention, a commercially available inorganic or organic antireflection film can be used if necessary. Furthermore, an antireflection film can be applied to the resist lower layer and used.

  As the antireflection film used as the lower layer of the resist, either an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon, or an organic film type made of a light absorber and a polymer material may be used. it can. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin-type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone-based light absorber described in JP-A-8-87115, and a low-molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.

  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 manufacture of precision integrated circuit elements, the pattern forming process on the resist film is carried out on the substrate (eg, silicon / silicon dioxide coated substrate, glass substrate, ITO substrate, quartz / chromium oxide coated substrate, etc.). A resist pattern is formed by applying a resist composition, forming a resist film, and then irradiating actinic rays or radiation such as KrF excimer laser light, electron beam, EUV light, etc., heating, developing, rinsing and drying. Can be formed.

Examples of the alkaline developer used in development include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, and primary amines such as ethylamine and n-propylamine. Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, An aqueous solution (usually 0.1 to 20% by mass) of an alkali such as a quaternary ammonium salt such as choline or a cyclic amine such as pyrrole or piperidine can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.
Among these developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and choline are more preferable.
The pH of the alkali developer is usually 10-15.

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

Synthesis Example 1 (Synthesis of Compound (S-1))
After dissolving 45.6 g of bis (3-cyclohexyl-4-hydroxyphenyl)-(4-hydroxyphenyl) methane in 300 ml of THF, 20 g of 1,8-diazabicyclo [5.4.0] -7-undecene and bromoacetic acid 20 g of t-butyl was added. After reacting at 60 ° C. for 5 hours, the reaction was further continued with stirring at room temperature for 3 hours. The reaction solution was neutralized with acetic acid and then added dropwise to 3 L of distilled water, and the precipitated white powder was collected by filtration. The obtained white powder was dissolved in 100 ml of tetrahydrofuran, crystallized again in 2 L of distilled water, and the deposited pale yellow powder was collected by filtration and then dried under reduced pressure at 40 ° C. The obtained powder was purified by column chromatography. After drying under reduced pressure at 70 ° C., it was dissolved in dry THF. After adding 0.2 g of p-toluenesulfonic acid thereto, 6 g of phenethyl vinyl ether was introduced and reacted to obtain a compound (S-1).

  Tables 1 and 2 below show the structures of the compounds (S-1) to (S-10) and the compound (S-2 ').

  The sulfonic acid generator and carboxylic acid generator used in the examples of the present invention were synthesized by a known synthesis method such as the synthesis method described in JP-A-2002-27806.

Example 1
Preparation and coating of positive resist Compound (S-1) 0.60 g
Acid-decomposable resin (R-34) 0.33g
Sulfonic acid generator (z2) 0.07g
Is dissolved in 8.8 g of propylene glycol monomethyl ether acetate, 0.002 g of D-2 (see below) as an organic basic compound, and Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc.) as a surfactant. 0.001 g) (abbreviated as “W-1”) was added and dissolved, and the resulting solution was microfiltered with a 0.1 μm aperture membrane filter to obtain a resist solution.
This resist solution was applied onto a 6-inch silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds to obtain a resist film having a thickness of 0.25 μm.
Formation of Positive Resist Pattern This resist film was irradiated with an electron beam using an electron beam drawing apparatus (Hitachi Ltd. HL750, acceleration voltage 50 KeV). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.

Sensitivity The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). The minimum irradiation energy when resolving a 0.13 μm line (line: space = 1: 1) was defined as sensitivity.
Resolving power The resolving power was defined as the limiting resolving power (line and space were separated and resolved) at the irradiation dose showing the above sensitivity.
LWR (Line with Roughness)
About the resist pattern obtained by carrying out similarly to the above, the line width was observed with the scanning electron microscope (S-9220 by Hitachi, Ltd.), and the fluctuation | variation (LWR) of the line width in the line width of 130 nm was observed. Using a length-measuring scanning electron microscope (SEM), the line width was detected at a plurality of positions in the measurement monitor, and the dispersion (3σ) of variations in the detected positions was used as an LWR index.
Density dependence Measure the line width of the dense pattern (line: space = 1: 1) and the line width of the isolated pattern in the 0.15μm line pattern at the irradiation dose showing the above sensitivity, and make the difference the density dependence .

As a result of Example 1, the sensitivity was 6.0 μC / cm ² , the resolving power was 0.08 μm, the LWR was 6.8 nm, and the density dependency was 8 nm.

Examples 2 to 10 and Comparative Example 1
Using the compounds shown in Table 3 below, resist preparation / coating and electron beam exposure evaluation were performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

  Abbreviations in the table are shown below.

[Organic basic compounds]
D-1: tri-n-hexylamine D-2: 2,4,6-triphenylimidazole D-3: tetra- (n-butyl) ammonium hydroxide

[Surfactant]
W-1: Fluorosurfactant, MegaFuck F-176 (Dainippon Ink Chemical Co., Ltd.)
W-2: Fluorine / silicone surfactant, MegaFac R08 (Dainippon Ink and Chemicals)
W-3: Silicone surfactant, siloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

  In Table 4 below, for the resins (R-1), (R-2), (R-22), (R-33), and (R-34), the repeating unit molar ratio (corresponding to each repeating unit in order from the left) ), Weight average molecular weight, and dispersity.

  From Table 3, it can be seen that the positive resist composition of the present invention has high sensitivity and high resolution with respect to pattern formation by electron beam irradiation, and is excellent in LWR and density dependency.

Using the EUV light (wavelength 13 nm) for the resist films of Examples 1 to 5 and Comparative Example 1, surface exposure was performed while changing the exposure amount by 0.5 mJ in the range of 0 to 5.0 mJ, and baking was further performed at 110 ° C. for 90 seconds. did. Then, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure dose was measured to obtain a sensitivity curve. In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. The larger the γ value, the better the dissolution contrast.
The results are shown in Table 5.

  From Table 5, it can be seen that the positive resist composition of the present invention is excellent in high sensitivity and high contrast in property evaluation by irradiation with EUV light.

Claims (6)

(A) a compound capable of generating an acid upon irradiation with an actinic ray or radiation, and (B) a carboxyl group protected by a group capable of leaving by the action of an acid and a phenolic hydroxyl group protected by a group capable of leaving by the action of an acid; A group having a molecular weight of 500 to 3,000 having different groups , wherein the carboxyl group is derived from a carboxyl group protected by a group capable of leaving by the action of an acid, and the group leaving by the action of the acid. The compound which produces | generates together the phenolic hydroxyl group derived from the phenolic hydroxyl group protected by (50) is 50 mass% with respect to the solid content whole quantity of a positive resist composition. A positive resist composition characterized in that it is ˜99.5% by mass. The positive resist composition according to claim 1, wherein the compound of component (B) is represented by the following general formula (I) or (II).

In general formula (I),
R ₁ , R ₂ , R ₃ and R ₄ may be each independently protected with a hydrogen atom, an alkyl group, a cycloalkyl group, a group that is released by the action of an acid, or a group that is not released by the action of an acid. It represents a good carboxyl group or a carboxyalkyl group which may be protected by a group capable of leaving by the action of an acid or a group not leaving by the action of an acid. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same as or different from each other.
R ₅ and R ₆ each independently represents a hydrogen atom or an organic group. A plurality of R ₅ and R ₆ may be the same as or different from each other.
R ₂ and R ₅ may combine to form a ring.
R ₄ and R ₆ may combine to form a ring.
W represents a group consisting of a single bond, a linear or branched alkylene group, a cycloalkylene group, an arylene group, or a combination thereof.
Provided that at least one of R ₁ , R ₂ , R ₃ and R ₄ represents a carboxyl group protected by a group capable of leaving by the action of an acid, or at least one of OR ₅ and OR _6. One represents a phenolic hydroxyl group protected with a group capable of leaving by the action of an acid.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 represent a positive integer.
m2 and m5 represent an integer of 0 or more.
However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2.

In general formula (II):
R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, a group that is eliminated by the action of an acid, or a group that is not removed by the action of an acid, or a carboxyl group or an acid A carboxyalkyl group which may be protected by a group capable of leaving by action or a group not leaving by the action of an acid. A plurality of R ₁₁ may combine to form a ring. A plurality of R ₁₂ may combine to form a ring. A plurality of R ₁₁ and R ₁₂ may be the same as or different from each other.
R ₁₃ represents a hydrogen atom or an organic group. A plurality of R ₁₃ may be the same as or different from each other.
R ₁₁ and R ₁₃ may combine to form a ring.
When there are a plurality of Xs, each independently represents a single bond or a divalent linking group.
However, at least one of R ₁₁ and R ₁₂ represents a carboxyl group protected by a group capable of leaving by the action of an acid, or OR ₁₃ is protected by a group capable of leaving by the action of an acid. Represents a phenolic hydroxyl group.
a represents an integer of 1 to 4.
m11 represents an integer of 0 or more.
m12 represents an integer of 0 or more. 3. The positive resist composition according to claim 2, wherein in general formula (I), at least one of R ₅ and R ₆ is a group capable of leaving by the action of an acid.   The positive resist composition according to claim 1, further comprising (C) a resin whose solubility in an alkali developer is increased by the action of an acid.   A resist film formed from the positive resist composition according to claim 1.   A pattern forming method comprising: exposing and developing the resist film according to claim 5.