JP5557938B2 - Positive resist composition and pattern forming method using the resist composition - Google Patents

Description

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

With the miniaturization of semiconductor elements, the exposure light source has become shorter in wavelength and the projection lens has a higher numerical aperture (high NA). Currently, an exposure machine with NA 0.84 using an ArF excimer laser having a 193 nm wavelength as a light source has been developed. ing. These can be expressed by the following equations as is generally well known.
(Resolving power) = k ₁ · (λ / NA)
(Depth of focus) = ± k ₂ · λ / NA ²
Where λ is the wavelength of the exposure light source, NA is the numerical aperture of the projection lens, and k ₁ and k ₂ are coefficients related to the process.
As a technique for increasing the resolving power in an optical microscope to increase the resolving power by further shortening the wavelength, a liquid with a high refractive index (hereinafter also referred to as “immersion liquid”) is conventionally filled between the projection lens and the sample. A so-called immersion method is known.
This “immersion effect” means that when λ ₀ is the wavelength of the exposure light in the air, n is the refractive index of the immersion liquid with respect to air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. The above-described resolving power and depth of focus can be expressed by the following equations.
(Resolving power) = k ₁ · (λ ₀ / n) / NA ₀
(Depth of focus) = ± k ₂ · (λ ₀ / n) / NA ₀ ²
That is, the immersion effect is equivalent to using an exposure wavelength having a wavelength of 1 / n. In other words, in the case of a projection optical system with the same NA, the depth of focus can be increased n times by immersion. This is effective for all pattern shapes, and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method which are currently being studied.
Examples of apparatuses in which this effect is applied to transfer of a fine image pattern of a semiconductor element are introduced in Patent Document 1, Patent Document 2, and the like.
Recent progress in immersion exposure technology is reported in Non-Patent Document 1, Non-Patent Document 2, Non-Patent Document 3, and the like. In the case of using an ArF excimer laser as a light source, pure water (refractive index of 1.44 at 193 nm) is considered to be most promising as an immersion liquid in terms of handling safety, transmittance at 193 nm, and refractive index.
Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. Explaining by taking a positive chemical amplification image forming method as an example, the acid generator in the exposed area is decomposed by exposure to generate an acid upon exposure, and the generated acid is reacted as a reaction catalyst by post exposure baking (PEB). Is used to change an alkali-insoluble group to an alkali-soluble group, and an exposed portion is removed by alkali development.
The ArF excimer laser (193 nm) resist using this chemical amplification mechanism is becoming mainstream at present, but when immersion exposure is performed, the formed line pattern collapses and becomes a defect during device manufacturing. However, the above-described composition was still insufficient in terms of the problem of pattern collapse and performance stability (exposure latitude) with respect to changes in exposure dose.
In the immersion exposure process, when exposure is performed using a scanning immersion exposure machine, the exposure speed decreases unless the immersion liquid moves following the movement of the lens. Concerned about giving. When the immersion liquid is water, it is preferable that the resist film is hydrophobic (high receding contact angle) because the water followability is good. Patent Document 4 describes that the resist film surface can be hydrophobized by adding a resin having fluorine atoms.
Patent Document 5 discloses that a compound that generates a sulfonic acid having a ring structure and a fluorine atom is used as an acid generator in order to provide a resist composition having high resolution.

JP-A-57-153433 JP-A-7-220990 International Publication No. 04/068242 Pamphlet JP 2007-249192 A JP 2007-161707 A

Bulletin of the International Society of Optical Engineering (Proc. SPIE), 2002, 4688, 11 J. et al. Vac. Sci. Tecnol. B 17 (1999) Bulletin of International Society of Optical Engineering (Proc. SPIE), 2000, 3999, 2nd page

However, the above technique does not achieve the trade-off relationship between the pattern collapse and the performance stability (exposure latitude) with respect to the change in exposure amount, and also follows the immersion liquid in immersion exposure. Improvement was also desired.
An object of the present invention is to improve the exposure latitude as the resist pattern collapses, and further to have good followability to the immersion liquid during immersion exposure, and the resist composition It is providing the pattern formation method using this.

式中、Ｘ^＋は、有機対イオンを表し、Ｒは、水素原子または下記式（ＩＩ）で表される有機基を表す。

式（ＩＩ）中、Ｒｃは、環状エーテル、環状チオエーテル、環状ケトン、環状炭酸エステル、ラクトンまたはラクタム構造を含んでも良い炭素数３〜３０の単環または多環の環状有機基を表す。Ｙは、水酸基、ハロゲン原子、シアノ基、カルボキシル基、炭素数１〜１０の炭化水素基、炭素数１〜１０のヒドロキシアルキル基、炭素数１〜１０のアルコキシ基、炭素数１〜１０のアシル基、炭素数２〜１０のアルコキシカルボニル基、炭素数２〜１０のアシルオキシ基、炭素数２〜１０のアルコキシアルキル基または炭素数１〜８のハロゲン化アルキル基を表す。ｍ＝０〜６であり、複数Ｙが存在する場合、互いに同一でも異なっても良い。ｎ＝１である。
（ｉ）樹脂（Ｂ）が、５〜７員環ラクトン構造にビシクロ構造を形成する形で他の環構造が縮環しているラクトン基を有する繰り返し単位を含有する。
（ｉｉ）樹脂（Ｂ）が、下記一般式（ＡＩＩ）で表される繰り返し単位を含有する。
（ｉｉｉ）樹脂（Ｂ）が、酸分解性基を有する繰り返し単位を２種含有する。

Ｒｂ₀は、水素原子、ハロゲン原子または炭素数１〜４のアルキル基を表す。
Ａｂは、−Ａｂ₁−ＣＯ₂−で表される２価の連結基を表す。
Ａｂ₁は、直鎖、分岐アルキレン基、単環または多環のシクロアルキレン基を表す。
Ｖは、下記一般式（ＬＣ１−１）〜（ＬＣ１−１６）の内のいずれかで示される構造を有する基を表す。

Ｒｂ₂は、炭素数１〜８のアルキル基、炭素数４〜７のシクロアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルコキシカルボニル基、カルボキシル基、ハロゲン原子、水酸基、シアノ基または酸分解性基である。ｎ_２は、０〜４の整数を表す。ｎ_２が２以上の時、複数存在する置換基Ｒｂ₂は、同一でも異なっていてもよく、また、複数存在する置換基Ｒｂ₂同士が結合して環を形成してもよい。
〔２〕
前記一般式（ＩＩ）において、Ｒｃがアダマンチル基を表すことを特徴とする〔１〕に記載のポジ型レジスト組成物。
〔３〕
前記樹脂（Ｂ）が、下記一般式（ＡＩ）で表される繰り返し単位を有することを特徴とする〔１〕又は〔２〕に記載のポジ型レジスト組成物。

一般式（ＡＩ）に於いて、
Ｘａ₁は、水素原子、メチル基、トリフルオロメチル基又はヒドロキシメチル基を表す。
Ｔは、単結合又は２価の連結基を表す。
Ｒｘ₁〜Ｒｘ₃は、それぞれ独立に、アルキル基又はシクロアルキル基を表す。
Ｒｘ₁〜Ｒｘ₃の少なくとも２つが結合して、シクロアルキル基を形成してもよい。
〔４〕
前記樹脂（Ｂ）が上記条件（ｉｉｉ）を満たし、かつ、前記一般式（ＡＩ）中のＲｘ_１〜Ｒｘ_３の少なくとも２つが結合して、単環のシクロアルキル基を形成することを特徴とする〔３〕に記載のポジ型レジスト組成物。
〔５〕
前記樹脂（ＨＲ）が、下記一般式（Ｆ２）〜（Ｆ４）で表される基を有することを特徴とする〔１〕〜〔４〕のいずれか１項に記載のポジ型レジスト組成物。

一般式（Ｆ２）〜（Ｆ４）中、
Ｒ₅₇〜Ｒ₆₈は、各々独立に、水素原子、フッ素原子、アルキル基、シクロアルキル基、またはアリール基を表す。但し、Ｒ₅₇〜Ｒ₆₁、Ｒ₆₂〜Ｒ₆₄およびＲ₆₅〜Ｒ₆₈のそれぞれにおいて、少なくとも１つは、フッ素原子又は少なくとも１つの水素原子がフッ素原子で置換されたアルキル基、シクロアルキル基、またはアリール基を表す。
Ｒ₆₂とＲ₆₃は、互いに連結して環を形成してもよい。
〔６〕
前記樹脂（ＨＲ）が、下記（ｘ）〜（ｚ）の群から選ばれる基を少なくとも１つ有していることを特徴とする〔１〕〜〔５〕のいずれか１項に記載のポジ型レジスト組成物。
（ｘ）アルカリ可溶性基、
（ｙ）アルカリ現像液の作用により分解し、アルカリ現像液中での溶解度が増大する基、
（ｚ）酸の作用により分解する基。
〔７〕
更に、溶剤としてプロピレングリコールモノメチルエーテルアセテートを含有する２種類以上の混合溶剤を含有することを特徴とする〔１〕〜〔６〕のいずれか１項に記載のポジ型レジスト組成物。
〔８〕
更に、溶剤としてプロピレンカーボネートを含有することを特徴とする〔１〕〜〔６〕のいずれか１項に記載のポジ型レジスト組成物。
〔９〕
〔１〕〜〔８〕のいずれか一項に記載のポジ型レジスト組成物により形成したレジスト膜。
〔１０〕
〔９〕に記載のレジスト膜を液浸露光する工程及び
該レジスト膜を現像する工程
を含むパターン形成方法。
本発明は上記の〔１〕〜〔１０〕に関するものであるが、以下、その他の事項についても記載した。
（１）（Ａ）下記一般式（Ｉ）で表される化合物、
（Ｂ）酸の作用によりアルカリ現像液に対する溶解度が増大する樹脂、及び、
（ＨＲ）フッ素原子及び珪素原子の少なくともいずれかを有する樹脂
を含有することを特徴とするポジ型レジスト組成物。 As a result of intensive studies to solve the above problems, the present inventor has reached the present invention shown below.
[1]
(A) a compound represented by the following general formula (I),
(B) a resin that satisfies at least one of the following conditions (i) to (iii) and whose solubility in an alkaline developer is increased by the action of an acid; and
(HR) A positive resist composition containing a resin having at least one of a fluorine atom and a silicon atom, which is different from the resin (B), wherein the amount of the resin (HR) added is The positive resist composition is 0.1 to 10% by mass based on the total solid content of the positive resist composition.

In the formula, X ⁺ represents an organic counter ion, and R represents a hydrogen atom or an organic group represented by the following formula (II).

In the formula (II), Rc represents a monocyclic or polycyclic organic group having 3 to 30 carbon atoms which may contain a cyclic ether, a cyclic thioether, a cyclic ketone, a cyclic carbonate, a lactone or a lactam structure. Y is a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a hydrocarbon group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an acyl having 1 to 10 carbon atoms. Group, a C2-C10 alkoxycarbonyl group, a C2-C10 acyloxy group, a C2-C10 alkoxyalkyl group, or a C1-C8 halogenated alkyl group. When m = 0 to 6 and there are a plurality of Y, they may be the same as or different from each other. n = 1.
(I) The resin (B) contains a repeating unit having a lactone group in which another ring structure is condensed so as to form a bicyclo structure in a 5- to 7-membered ring lactone structure.
(Ii) The resin (B) contains a repeating unit represented by the following general formula (AII).
(Iii) The resin (B) contains two types of repeating units having an acid-decomposable group.

Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.
Ab represents a divalent linking group represented by —Ab ₁ —CO ₂ —.
Ab ₁ represents a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group.
V represents a group having a structure represented by any of the following general formulas (LC1-1) to (LC1-16).

Rb ₂ represents an alkyl group having 1 to 8 carbon atoms, cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a hydroxyl group, It is a cyano group or an acid-decomposable group. n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of substituents Rb ₂ may be the same or different, and a plurality of substituents Rb ₂ may be bonded to form a ring.
[2]
The positive resist composition as described in [1], wherein in the general formula (II), Rc represents an adamantyl group.
[3]
The positive resist composition as described in [1] or [2], wherein the resin ( B ) has a repeating unit represented by the following general formula (AI).

In general formula (AI),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group.
At least two of Rx _{1 to} Rx ₃ may be bonded to form a cycloalkyl group.
[4]
The resin (B) satisfies the above condition (iii), and at least two of Rx ₁ to Rx _{3 in} the general formula (AI) are bonded to form a monocyclic cycloalkyl group, The positive resist composition according to [3].
[5]
The positive resist composition according to any one of [1] to [4], wherein the resin (HR) has groups represented by the following general formulas (F2) to (F4).

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, a cycloalkyl group, or an aryl group. However, in each of _{R 57 ~R 61, R 62 ~R} 64 and R ₆₅ to R _68, at least one is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, a cycloalkyl group, Or represents an aryl group.
R ₆₂ and R ₆₃ may be connected to each other to form a ring .
[6]
The positive electrode according to any one of [1] to [5], wherein the resin (HR) has at least one group selected from the following groups (x) to (z): Type resist composition.
(X) an alkali-soluble group,
(Y) a group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer;
(Z) A group that decomposes by the action of an acid.
[7]
The positive resist composition according to any one of [1] to [6], further comprising two or more mixed solvents containing propylene glycol monomethyl ether acetate as a solvent.
[8]
Furthermore, propylene carbonate is contained as a solvent, The positive resist composition of any one of [1]-[6] characterized by the above-mentioned.
[9]
A resist film formed from the positive resist composition according to any one of [1] to [8].
[10]
[9] A pattern forming method comprising a step of immersion exposure of the resist film according to [9] and a step of developing the resist film.
The present invention relates to the above [1] to [10], but other matters are also described below.
(1) (A) a compound represented by the following general formula (I),
(B) a resin whose solubility in an alkaline developer is increased by the action of an acid, and
(HR) A positive resist composition comprising a resin having at least one of a fluorine atom and a silicon atom.

In the formula, X ⁺ represents an organic counter ion, and R represents a hydrogen atom or an organic group.

(2) The resin (HR) has at least one group represented by any one of the general formulas (F2) to (F4) and (CS-1) to (CS-3), The positive resist composition as described in (1).

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, a cycloalkyl group, or an aryl group. However, in each of _{R 57 ~R 61, R 62 ~R} 64 and R ₆₅ to R _68, at least one is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, a cycloalkyl group, Or represents an aryl group. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

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

(3) A repeating unit derived from an acrylate or methacrylate in which the resin (HR) has any one of the groups represented by the general formulas (F2) to (F4) and the general formulas (CS-1) to (CS-3) The positive resist composition as described in (2) above, which contains at least one of the above.
(4) The positive resist composition according to any one of (1) to (3), wherein the resin (B) contains a repeating unit containing a lactone structure.

(5) The positive resist composition according to any one of (1) to (4), wherein the resin (B) has an acid-decomposable group having a monocyclic or polycyclic structure.
(6) The content rate of resin (HR) is 0.1-10 mass% with respect to the total solid in a positive resist composition, Any one of said (1)-(5) Positive resist composition.

(7) The receding contact angle of water with respect to the resist film formed from the positive resist composition as described in any one of (1) to (6) above is 70 degrees or more. The positive resist composition according to any one of 6).
(8) A pattern forming method comprising a step of forming a resist film using the positive resist composition according to any one of (1) to (7), immersion exposure, and development. .

  According to the present invention, the exposure latitude is improved along with the collapse of the resist pattern, and the followability to the immersion liquid in the immersion exposure is good, and the positive resist composition and the resist composition are used. A pattern forming method can be provided.

Schematic diagram of water followability evaluation method

[1] (A) A compound represented by the general formula (I).
The compound represented by the general formula (I) contained in the positive resist composition of the present invention is a compound that generates an acid corresponding to the anion moiety in the general formula (I) upon irradiation with actinic rays or radiation.

(In the formula, X ⁺ represents an organic counter ion, and R represents a hydrogen atom or an organic group.)
In general formula (I), R represents a hydrogen atom or an organic group, preferably an organic group having 1 to 40 carbon atoms, more preferably an organic group having 3 to 20 carbon atoms. Most preferably, it is an organic group represented by II).
The organic group for R may have one or more carbon atoms. Preferably, the atom bonded to the oxygen atom in the ester bond represented by the general formula (I) is a carbon atom, such as an alkyl group, Examples include a cycloalkyl group, an aryl group, an aralkyl group, and a group having a lactone structure, and the chain may have a hetero atom such as an oxygen atom or a sulfur atom. These may have each other as a substituent, and may have a substituent such as a hydroxyl group, an acyl group, an acyloxy group, an oxy group (═O), or a halogen atom.

(In Formula (II), Rc represents a monocyclic or polycyclic organic group having 3 to 30 carbon atoms which may contain a cyclic ether, a cyclic thioether, a cyclic ketone, a cyclic carbonate, a lactone, or a lactam structure. Y Are a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a hydrocarbon group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an acyl group having 1 to 10 carbon atoms. Represents an alkoxycarbonyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 10 carbon atoms, an alkoxyalkyl group having 2 to 10 carbon atoms, and a halogenated alkyl group having 1 to 8 carbon atoms, and m = 0 to 6. When there are a plurality of Y, they may be the same or different, and n = 0 to 10.
The total number of carbon atoms constituting the R group represented by formula (II) is preferably 40 or less.
It is preferable that n = 0 to 3 and Rc is a monocyclic or polycyclic organic group having 7 to 16.
300-1000 are preferable, as for the molecular weight of the compound represented by general formula (I), 400-800 are more preferable, and 500-700 are the most preferable.

Examples of the organic counter ion of X ⁺ include a sulfonium cation and an iodonium cation.
In the compound of the general formula (I), as a preferred form, a compound represented by the general formula (Z _SC1 ) or the general formula (Z _IC1 ) can be exemplified.

In the general formula (Z _SC1 ), the definition and preferred range of R are the same as those in the general formula (I).
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z _SC1-1 ), (Z _SC1 -2) and (Z _SC1-3 ) which will be described later.

A compound having a plurality of structures represented by the general formula (Z _SC1 ) may also be used. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (Z _SC1), bound to at least one of R ₂₀₁ to R ₂₀₃ of another compound represented by the general formula (Z _SC1) It may be a compound having a structure.

More preferred (Z _SC1 ) components include the compounds (Z _SC1 -1), (Z _SC1 -2), and (Z _SC1 -3) described below.

The compound (Z _SC1-1 ) is an arylsulfonium compound in which at least one of R _{201 to} R _{203 in} the general formula (Z _SC1 ) is an aryl group, that is, a compound having arylsulfonium as a cation.
The definition and preferred range of R are the same as the definition in general formula (I).

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

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

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

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

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

Next, the compound (Z _SC1-2 ) will be described.
The definition and preferred range of R are the same as the definition in general formula (I).
The compound (Z _SC1 -2) is a compound in which R _{201 to} R ₂₀₃ in the formula (Z _SC1 ) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

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

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

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

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

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

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

The compound (Z _SC1 -3) is a compound represented by the following general formula (Z _SC1 -3), and is a compound having a phenacylsulfonium salt structure.

In the general formula (Z _SC1 -3),
The definition and preferred range of R are the same as the definition in general formula (I).
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

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

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

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

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

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

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

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

In the general formula (Z _IC1 )
The definition and preferred range of R are the same as the definition in general formula (I).
R ₂₀₄ to R ₂₀₅ 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 _205, more preferably a phenyl group. Aryl group R ₂₀₄ to R ₂₀₅ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R ₂₀₄ to R _205, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _205, cycloalkyl groups may have a substituent. Aryl group, an alkyl group R ₂₀₄ to R _205, the cycloalkyl group substituents which may have include an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

  Specific examples of the compound represented by formula (I) include the following compounds, but are not limited thereto.

The compound represented by the general formula (I) can be synthesized by a known method, for example, according to the method described in JP-A No. 2007-161707.
The compound represented by general formula (I) can be used 1 type or in combination of 2 or more types.
The content of the compound represented by the general formula (I) in the positive resist composition is preferably 0.1 to 20% by mass, more preferably 0.8%, based on the total solid content of the positive resist composition. It is 5-10 mass%, More preferably, it is 1-7 mass%.

[2] (A ′) Other Compound that Generates Acid upon Irradiation with Actinic Ray or Radiation The positive resist composition of the present invention contains other actinic rays or radiation together with the compound represented by the general formula (i). May contain a compound that generates an acid upon irradiation (hereinafter also referred to as a “combination acid generator”).
As the combined acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, irradiation of actinic ray or radiation used for micro resist, etc. The known compounds that generate an acid 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, such as US Pat. No. 3,849,137, German Patent No. No. 3914407, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, The compounds described in JP-A-62-153853 and 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, etc. can also be used.

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

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

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

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

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

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

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

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

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

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

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

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

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

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

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

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compounds, namely, compounds containing an arylsulfonium as a cation.

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

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

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

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

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

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

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

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

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

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

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

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

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Among the combined acid generators, particularly preferred examples are given below.

The combined acid generator can be used alone or in combination of two or more.
The content of the compound that generates an acid upon irradiation with actinic rays or radiation (acid generator) in the positive resist composition is 0.1 to 20% by mass based on the total solid content of the positive resist composition. More preferably, it is 0.5-10 mass%, More preferably, it is 1-7 mass%.
Moreover, 0.1-100 mass% of the total acid generator is preferable, and, as for the ratio of the compound represented by said Formula (I) among the acid generators in a positive resist composition, 20-100 mass% is more. Preferably, 50-100 mass% is especially preferable.

[3] (B) Resin whose solubility in an alkaline developer is increased by the action of an acid (B) The resin of the component is a resin (acid-decomposable resin) whose solubility in an alkaline developer is increased by the action of an acid. The resin has a group (hereinafter also referred to as “acid-decomposable group”) that is decomposed by the action of an acid to generate an alkali-soluble group in the main chain or side chain, or both of the main chain and side chain.
Alkali-soluble groups include phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) imides. Group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group, etc. Is mentioned.
Preferred alkali-soluble groups include carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
A preferable group as the acid-decomposable group is a group obtained by substituting the hydrogen atom of these alkali-soluble groups with a group capable of leaving with an acid.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.
The acid-decomposable group preferably has a monocyclic or polycyclic structure. Examples of the repeating unit having such an acid-decomposable group include -C (Rx ₁ ) (Rx ₂ ) () in the case where at least one of Rx _{1 to} Rx ₃ is a cycloalkyl group in the general formula (AI) described later. Examples of the structure represented by Rx ₃ ) include a monocyclic or polycyclic structure.

  The repeating unit having an acid-decomposable group contained in the component (B) resin is preferably a repeating unit represented by the following general formula (AI).

In general formula (AI),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group.
At least two of Rx _{1 to} Rx ₃ may be bonded to form a cycloalkyl group.

Examples of the divalent linking group for T include an alkylene group, —COO—Rt— group, —O—Rt— group, and the like. In the formula, Rt represents an alkylene group or a cycloalkylene group.
T is preferably a single bond or a —COO—Rt— group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a —CH ₂ — group or a — (CH ₂ ) ₃ — group.
The alkyl group of Rx _{1 to} Rx ₃ may be linear or branched, and is a carbon such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. The thing of number 1-4 is preferable.
The cycloalkyl group represented by Rx _{1 to} Rx ₃ may be monocyclic or polycyclic, and is a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, or a tetracyclododecanyl group. And a polycyclic cycloalkyl group such as an adamantyl group are preferred.
Examples of the cycloalkyl group formed by combining at least two of Rx _{1 to} Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, A polycyclic cycloalkyl group such as an adamantyl group is preferred.
It is preferable that Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to form the above-described cycloalkyl group.

  As for the content rate of the repeating unit which has an acid-decomposable group, 20-50 mol% is preferable with respect to all the repeating units in resin (B), More preferably, it is 25-45 mol%.

  Although the specific example of the repeating unit which has a preferable acid-decomposable group is shown below, this invention is not limited to this.

In the formula shown below, Xa ₁ represents H, CH ₃ , CF ₃ , or CH ₂ OH.

  The resin as the component (B) preferably further has a repeating unit having at least one group selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group.

  The repeating unit having a lactone group that can be contained in the component (B) resin will be described. Any lactone group can be used as long as it has a lactone structure, but it is preferably a 5- to 7-membered ring lactone structure, and forms a bicyclo structure or a spiro structure in the 5- to 7-membered ring lactone structure. The other ring structure is preferably condensed. It is more preferable to have a repeating unit having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). The lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and a specific lactone structure is used. This improves line edge roughness and development defects.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferably, they are a C1-C4 alkyl group, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring.

  Examples of the repeating unit having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AII).

In general formula (AII),
Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom. Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Preferred are a hydrogen atom, a methyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom and a methyl group are particularly preferred.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent linking group obtained by combining these. Preferably a single bond, -Ab ₁ -CO ₂ - is a divalent linking group represented by.
Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.
V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-16).

  The repeating unit having a lactone group usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

  The content of the repeating unit having a lactone group is preferably from 15 to 60 mol%, more preferably from 20 to 50 mol%, still more preferably from 30 to 50 mol%, based on all repeating units in the resin (B).

  Specific examples of the repeating unit having a lactone group are listed below, but the present invention is not limited thereto.

  Particularly preferred repeating units having a lactone group include the following repeating units. By selecting an optimal lactone group, the pattern profile and the density dependency are improved.

  The resin as the component (B) preferably has a repeating unit having a hydroxyl group or a cyano group. This improves the substrate adhesion and developer compatibility. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferred hydroxyl group or cyano group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferred.

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

  Examples of the repeating unit having a partial structure represented by the general formulas (VIIa) to (VIId) include the repeating units represented by the following general formulas (AIIa) to (AIId).

In the general formulas (AIIa) to (AIId),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₂ c to R ₄ c are in the general formula (VIIa) ~ (VIIc), same meanings as R ₂ c~R ₄ c.

  The content of the repeating unit having a hydroxyl group or a cyano group is preferably from 5 to 40 mol%, more preferably from 5 to 30 mol%, still more preferably from 10 to 25 mol%, based on all repeating units in the resin (B).

  Specific examples of the repeating unit having a hydroxyl group or a cyano group are given below, but the present invention is not limited thereto.

  The resin of component (B) preferably has a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, and an aliphatic alcohol (for example, hexafluoroisopropanol group) substituted with an electron-attracting group at the α-position. It is more preferable to have a repeating unit. By containing the repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. The repeating unit having an alkali-soluble group includes a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or an alkali in the main chain of the resin through a linking group. Either a repeating unit to which a soluble group is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is used at the time of polymerization and introduced at the end of the polymer chain, and the linking group is monocyclic or polycyclic. It may have a cyclic hydrocarbon structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  As for the content rate of the repeating unit which has an alkali-soluble group, 0-20 mol% is preferable with respect to all the repeating units in resin (B), More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

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

  As the repeating unit having at least one group selected from a lactone group, a hydroxyl group, a cyano group and an alkali-soluble group, more preferably, a repeating unit having at least two groups selected from a lactone group, a hydroxyl group, a cyano group and an alkali-soluble group Preferably, it is a repeating unit having a cyano group and a lactone group. Particularly preferred is a repeating unit having a structure in which a cyano group is substituted on the lactone structure of (LCI-4).

  The resin of component (B) may further have a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, diamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and cyclohexyl (meth) acrylate repeating units.

  In addition to the above repeating structural unit, the resin of component (B) is dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, such as resolution, heat resistance, and sensitivity. Various repeating structural units can be included for the purpose of adjusting the above.

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

  As a result, the performance required for the resin of component (B), in particular, (1) solubility in coating solvent, (2) film forming property (glass transition point), (3) alkali developability, (4) film slipping Fine adjustments such as (hydrophobicity and alkali-soluble group selection), (5) adhesion of the unexposed part to the substrate, and (6) dry etching resistance are possible.

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

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

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

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

  As the resin of component (B), preferably, all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units. Although it can be used, the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units. More preferably, the (meth) acrylate repeating unit having an acid-decomposable group represented by the general formula (AI) is 20 to 50 mol%, the (meth) acrylate repeating unit having a lactone group is 20 to 50 mol%, It is a copolymer having 5 to 30 mol% of (meth) acrylate-based repeating units having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and further containing 0 to 20 mol% of other (meth) acrylate-based repeating units. .

  Preferred examples of the repeating unit having an acid-decomposable group include t-butoxycarbonyloxystyrene, 1-alkoxyethoxystyrene, a repeating unit of (meth) acrylic acid tertiary alkyl ester, and the like. The repeating unit by 2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate is more preferable.

The resin of component (B) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

The weight average molecular weight of the component (B) resin is preferably 1,000 to 200,000, more preferably 2,000 to 20,000, and still more preferably 3,000 as a polystyrene-converted value by the GPC method. ˜15,000, particularly preferably 3,000 to 10,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The degree of dispersion (molecular weight distribution) is usually 1 to 3, preferably 1 to 2.6, more preferably 1 to 2, and particularly preferably 1.4 to 1.7. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.

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

  The resin of the component (B) of the present invention preferably further contains a repeating unit represented by the general formula (IX) that has neither a hydroxyl group nor a cyano group.

In general formula (IX), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. Ra is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.

The cyclic structure possessed by R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include cycloalkenyl having 3 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like, and cycloalkyl groups having 3 to 12 carbon atoms and cyclohexenyl group. Groups. Preferable monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferable examples include a cyclopentyl group and a cyclohexyl group.

The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group, and examples of the ring assembly hydrocarbon group include a bicyclohexyl group and a perhydronaphthalenyl group. As the bridged cyclic hydrocarbon ring, for example, bicyclic such as pinane, bornane, norpinane, norbornane, bicyclooctane ring (bicyclo [2.2.2] octane ring, bicyclo [3.2.1] octane ring, etc.) Hydrocarbon rings and tricyclic hydrocarbon rings such as homobredan, adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.1.1 ^2,5 ] undecane ring, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, and tetracyclic hydrocarbon rings such as perhydro-1,4-methano-5,8-methanonaphthalene ring. The bridged cyclic hydrocarbon ring includes a condensed cyclic hydrocarbon ring such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydroindene. A condensed ring in which a plurality of 5- to 8-membered cycloalkane rings such as a phenalene ring are condensed is also included.

Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo [5,2,1,0 ^2,6 ] decanyl group, and the like. More preferable examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

  These alicyclic hydrocarbon groups may have a substituent, and preferred substituents include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino group protected with a protecting group, and the like. It is done. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and the substituent that may further have a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino protected with a protecting group The group can be mentioned.

  Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups. 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl groups, etc., aliphatic acyl groups having 1 to 6 carbon atoms, alkoxycarbonyl Examples of the group include an alkoxycarbonyl group having 2 to 4 carbon atoms.

The content of the repeating unit represented by the general formula (IX) having neither a hydroxyl group nor a cyano group is preferably from 0 to 40 mol%, more preferably based on all repeating units in the resin (B). 0 to 20 mol%.
Specific examples of the repeating unit represented by the general formula (IX) are shown below, but the present invention is not limited thereto.

[4] (HR) Resin having at least one of fluorine atom and silicon atom The positive resist composition of the present invention comprises a resin (HR) having at least one of fluorine atom and silicon atom (hereinafter, hydrophobic resin ( HR)). Thereby, hydrophobic resin (HR) is unevenly distributed on the resist film surface layer, and when exposed through an immersion liquid such as water, the receding contact angle of the resist film surface with respect to the immersion liquid when used as a resist film is improved, The followability of the immersion liquid can be improved. It is preferable that the hydrophobic resin (HR) does not have an alkali-soluble group as described later and does not have alkali solubility.
The receding contact angle of the resist film is preferably 60 ° to 90 °, more preferably 70 ° to 85 °. The addition amount can be adjusted and used as appropriate so that the receding contact angle of the resist film falls within the above range, but is preferably 0.1 to 10% by mass based on the total solid content of the positive resist composition, More preferably, it is 0.1-5 mass%.
Hydrophobic resin (HR) is ubiquitous at the interface as described above, but unlike a surfactant, it does not necessarily have a hydrophilic group in the molecule, and polar / nonpolar substances are mixed uniformly. There is no need to contribute.
The receding contact angle is the contact angle measured when the contact line at the droplet-substrate interface recedes, and is useful for simulating the ease of droplet movement under dynamic conditions. It is generally known. In simple terms, it can be defined as the contact angle when the droplet interface recedes when the droplet discharged from the needle tip is deposited on the substrate and then sucked into the needle again. It can be measured by using a contact angle measuring method generally called an expansion / contraction method.
In the immersion exposure process, the immersion head needs to move on the wafer following the movement of the exposure head to scan the wafer at high speed to form the exposure pattern. In this case, the contact angle of the immersion liquid with respect to the resist film is important, and the resist is required to follow the high-speed scanning of the exposure head without remaining droplets.

  The fluorine atom or silicon atom in the hydrophobic resin (HR) may be contained in the main chain of the resin or may be substituted on the side chain.

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

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

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

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoromethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 1,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -C (CF _{3) 2} OH is preferred.
The resin (HR) preferably contains at least one repeating unit derived from an acrylate or methacrylate having a group represented by any one of the general formulas (F2) to (F4).

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

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

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents an alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L _{3 to} L ₅ each independently represents a single bond or a divalent linking group. As the divalent linking group, an alkylene group, a phenylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a ureylene group is used alone or in combination of two or more groups. Combinations are listed.
n represents an integer of 1 to 5.
The resin (HR) preferably contains at least one repeating unit derived from an acrylate or methacrylate having a group represented by any one of the general formulas (CS-1) to (CS-3).

Hereinafter, although the specific example of the repeating unit which has group represented by general formula (CS-1)-(CS-3) is given, this invention is not limited to this. In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .

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

(X) Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) ( Alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) ) And a methylene group.
Preferred alkali-soluble groups include fluorinated alcohol groups (preferably hexafluoroisopropanol), sulfonimide groups, and bis (carbonyl) methylene groups.

Examples of the repeating unit having an alkali-soluble group (x) include a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a main group of the resin via a linking group. Examples include repeating units in which an alkali-soluble group is bonded to the chain. Furthermore, a polymerization initiator or a chain transfer agent having an alkali-soluble group can be used at the time of polymerization to be introduced at the end of the polymer chain. Is also preferable.
The content of the repeating unit having an alkali-soluble group (x) is preferably from 1 to 50 mol%, more preferably from 3 to 35 mol%, still more preferably from 5 to 20 mol%, based on all repeating units in the polymer.

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

(Y) Examples of the group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer include a group having a lactone structure, an acid anhydride group, an acid imide group, and the like, and preferably a lactone A group having a structure.
As the repeating unit having a group (y) that is decomposed by the action of an alkali developer and increases the solubility in the alkali developer, an alkali is added to the main chain of the resin, such as a repeating unit of an acrylate ester or a methacrylate ester. A polymerization initiator having a repeating unit to which a group (y) that decomposes by the action of the developer and increases the solubility in an alkali developer is bonded, or a group (y) that increases the solubility in an alkali developer And a chain transfer agent used at the time of polymerization are preferably introduced at the end of the polymer chain.
The content of the repeating unit having a group (y) whose solubility in an alkali developer is increased is preferably 1 to 40 mol%, more preferably 3 to 30 mol%, still more preferably based on all repeating units in the polymer. 5 to 15 mol%.

  Specific examples of the repeating unit having a group (y) that increases the solubility in an alkali developer include the same repeating units as those having a lactone structure exemplified for the resin of the component (B).

  In the hydrophobic resin (HR), examples of the repeating unit having a group (z) that is decomposed by the action of an acid include the same repeating units having an acid-decomposable group as mentioned for the resin of the component (B). . In the hydrophobic resin (HR), the content of the repeating unit having a group (z) that is decomposed by the action of an acid is preferably 1 to 80 mol%, more preferably 10 to 10%, based on all repeating units in the polymer. 80 mol%, more preferably 20 to 60 mol%.

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

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

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

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

  The weight average molecular weight of the hydrophobic resin (HR) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and even more preferably 2,000 to 15,000. is there.

  As for the hydrophobic resin (HR), it is preferable that the residual monomer and oligomer components are 0 to 10% by mass, more preferably, as in the resin of the component (B), there are few impurities such as metals. Is more preferably 0 to 5% by mass and 0 to 1% by mass. Thereby, a resist having no change over time such as foreign matter in liquid or sensitivity can be obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 5, more preferably 1 to 3, and still more preferably from the viewpoints of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is the range of 1-2.

  As the hydrophobic resin (HR), various commercially available products can be used, or they can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The concentration of the reaction is 5 to 50% by mass, preferably 30 to 50% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

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

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

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

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

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

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

  Specific examples of the hydrophobic resin (HR) are shown below. Table 1 below shows the molar ratio of the repeating units in each resin (corresponding to each repeating unit in order from the left), the weight average molecular weight, and the degree of dispersion.

[5] Solvent Examples of the solvent that can be used in preparing the positive resist composition by dissolving the above-described components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate ester, Organic solvents such as alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds that may contain rings (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, alkyl pyruvates, etc. Can be mentioned.

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

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

  Examples of the cyclic lactone include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, and γ-octano. Preferred are iclactone and α-hydroxy-γ-butyrolactone.

  Examples of the monoketone compound which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2 -Methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-hexen-2-one 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3- Methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcycloheptanone, 3-methyl Preferred is cycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.
Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.
As a solvent which can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid -2- (2-ethoxyethoxy) ethyl and propylene carbonate are mentioned.
In the present invention, the above solvents may be used alone or in combination of two or more.

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

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

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

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

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

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

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

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

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

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

  These basic compounds are used alone or in combination of two or more.

  The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of the total solid of a positive resist composition, Preferably it is 0.01-5 mass%.

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

[7] Surfactant The positive resist composition of the present invention preferably further contains a surfactant, and a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant, It is more preferable to contain either one or two or more surfactants having both fluorine atoms and silicon atoms.

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

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

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

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

  These surfactants may be used alone or in several combinations.

  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).

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

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

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

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

[9] Dissolution-inhibiting compound having a molecular weight of 3000 or less, which decomposes by the action of an acid to increase the solubility in an alkali developer, and increases the solubility in an alkali developer by the action of an acid, having a molecular weight of 3000 or less As a dissolution inhibiting compound (hereinafter also referred to as “dissolution inhibiting compound”), a cholic acid containing an acid-decomposable group described in Proceeding of SPIE, 2724,355 (1996) is used in order not to lower the permeability of 220 nm or less. Alicyclic or aliphatic compounds containing acid-decomposable groups such as derivatives are preferred. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the component (B) resin.

  When the positive resist composition of the present invention is exposed with a KrF excimer laser or irradiated with an electron beam, it preferably contains a structure in which the phenolic hydroxyl group of the phenol compound is substituted with an acid-decomposable group. As a phenol compound, what contains 1-9 phenol frame | skeleton is preferable, More preferably, it contains 2-6 pieces.

  The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution inhibiting compound is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, based on the total solid content of the positive resist composition.

  Specific examples of the dissolution inhibiting compound are shown below, but the present invention is not limited thereto.

[10] Other additives In the positive resist composition of the present invention, if necessary, a dye, a plasticizer, a photosensitizer, a light absorber, and a compound that promotes solubility in a developer (for example, A phenol compound having a molecular weight of 1000 or less, an alicyclic compound having a carboxyl group, or an aliphatic compound) can be contained.

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

[11] Pattern formation method Resolution is achieved by filling a liquid (immersion medium) having a higher refractive index than air between the resist film and the lens during exposure to actinic rays or radiation and performing exposure (immersion exposure). Can be increased.
The positive resist composition of the present invention is suitable for patterning by such immersion exposure.

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

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

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

The positive resist composition of the present invention is preferably used at a film thickness of 30 to 250 nm, more preferably at a film thickness of 30 to 200 nm, from the viewpoint of improving resolution. Such a film thickness can be obtained by setting the total solid content concentration in the positive resist composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The total solid content concentration in the positive resist composition is generally 1 to 10% by mass, more preferably 1 to 8.0% by mass, and still more preferably 1.0 to 6.0% by mass.

  The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows. The pore size of the filter used for filter filtration is preferably 0.1 microns or less, more preferably 0.05 microns or less, and even more preferably 0.03 microns or less made of polytetrafluoroethylene, polyethylene, or nylon.

For example, a positive resist composition is coated on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit element by an appropriate coating method such as a spinner or a coater, and dried to form a resist film. Form.
The resist film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, etc., preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 200 nm. Far ultraviolet light, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, etc., ArF excimer laser, F ₂ excimer laser, EUV (13 nm ) Is preferred.

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

In the development step, an alkaline developer is used as follows. Examples of the alkali developer for the positive resist composition include inorganic hydroxides 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, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide Alkaline aqueous solutions of cyclic amines such as quaternary ammonium salts such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, the content of this invention is not limited by this. In addition, Example 5, 7, 9, 12, 14, 16, and 17 shall be read as a reference example, respectively.

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

In the same manner as in Synthesis Example 1, acid-decomposable resins (2) to (18) were synthesized.
Table 1 below shows the structures of the acid-decomposable resins (1) to (18), the molar ratio of repeating units in each resin (in order from the left in the structural formula), the weight average molecular weight, and the degree of dispersion.

Synthesis Example 2 Synthesis of Resin (HR-17) 47.2 g of hexafluoroisopropyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in propylene glycol monomethyl ether acetate to prepare 170 g of a solution having a solid content concentration of 20% by mass. To this solution was added 8 mol% (3.68 g) of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd., and this was heated to 80 ° C. over 4 hours under a nitrogen atmosphere, 20.0 g of propylene glycol monomethyl ether acetate. It was dripped in. After completion of dropping, the reaction solution was stirred for 2 hours to obtain a reaction solution (1). After completion of the reaction, the reaction solution (1) was cooled to room temperature and dropped into a 20 times amount of a mixed solvent of methanol / water = 8/1. The separated oily compound was recovered by decantation to obtain 24.1 g of the target resin (HR-17).
The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 4400, and the degree of dispersion was 1.3.
Each of the resins (HR) shown in Table 2 was synthesized in the same manner as in Synthesis Example 2 above.

[Examples and Comparative Examples]
<Resist preparation>
The components shown in Table 2 below were dissolved in a solvent to prepare a solution having a total solid content concentration of 6% by mass, and this was filtered through a polyethylene filter having a pore size of 0.1 μm to prepare a positive resist solution. The prepared positive resist composition was evaluated by the following method, and the results are shown in the same table. In addition, about each component in the same table, the ratio when using two or more is a mass ratio.
The amount of the resin (HR) added is mass% with respect to the total solid content of the positive resist composition.

[Image performance test]
[Exposure conditions]
This condition is to form a resist pattern by an immersion exposure method using pure water.
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 78 nm. The positive resist composition prepared thereon was applied and baked at 130 ° C. for 60 seconds to form a resist film having a thickness of 250 nm. The obtained wafer was subjected to pattern exposure using an ArF excimer laser immersion scanner (NA 0.85). Ultra pure water was used as the immersion liquid. Thereafter, the mixture was heated at 100 ° C. for 60 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsed with pure water, and spin-dried to obtain a resist pattern.

[Pattern collapse evaluation]
When the line width of a line pattern formed by increasing the exposure amount from the optimum exposure amount is set as the optimal exposure amount and the exposure amount for reproducing the line and space mask pattern having a line width of 85 nm is reduced. Defined with line width that resolves without falling down. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur and the resolution is higher.

[Exposure latitude (EL)]
The exposure amount that reproduces a line-and-space mask pattern with a line width of 85 nm is set as the optimal exposure amount, and when the exposure amount is changed, an exposure amount width that allows the pattern size to be 85 nm ± 10% is obtained, and this value is the optimal exposure Divided by the amount and expressed as a percentage. The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure latitude (EL).

[Evaluation of receding contact angle]
The prepared positive resist composition was spin-coated on a silicon wafer and baked on a hot plate to form a 150 nm resist film. The receding contact angle of water droplets (measurement temperature: 25 ° C.) was measured by the expansion / contraction method of a dynamic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). An initial droplet size of 35 μL was sucked at a speed of 6 L / sec for 5 seconds, and a value with a stable dynamic contact angle during suction was defined as a receding contact angle.

[Water followability evaluation]
The prepared positive resist composition was applied onto a silicon wafer and baked at 120 ° C. for 60 seconds to form a 160 nm resist film. Next, as shown in FIG. 1, pure water 2 was filled between the resist-coated substrate 1 and the quartz glass substrate 3 coated with the obtained positive resist composition.
In this state, the quartz glass substrate 3 was moved (scanned) in parallel to the surface of the resist-coated substrate 1, and the state of the pure water 2 following it was visually observed. Gradually increase the scan speed of the quartz glass substrate 3 and evaluate the water followability by obtaining the limit scan speed at which the pure water 2 cannot follow the scan speed of the quartz glass substrate 3 and water droplets begin to remain on the receding side. went. The case where the limit scanning speed was 500 mm / second or more was evaluated as “◯”, the case where it exceeded 300 mm / second and less than 500 mm / second was evaluated as “Δ”, and the case where it was 300 mm / second or less was evaluated as “X”. As this limit scan speed is larger, water can follow a higher scan speed, and the water followability on the resist film is better.

The symbols in Table 2 are as follows.
The acid generator corresponds to that exemplified above.

N-1: N, N-dibutylaniline N-2: N, N-dihexylaniline N-3: 2,6-diisopropylaniline N-4: tri-n-octylamine N-5: N, N-dihydroxyethyl Aniline N-6: 2,4,5-triphenylimidazole N-7: Tris (methoxyethoxyethyl) amine N-8: 2-phenylbenzimidazole

W-1: Megafac F176 (Dainippon Ink Chemical Co., Ltd., fluorine-based)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd., fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd., silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF656 (manufactured by OMNOVA, fluorine-based)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)

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

1 resist coated substrate 2 pure water 3 quartz glass substrate

Claims (10)

(A) a compound represented by the following general formula (I),
(B) a resin that satisfies at least one of the following conditions (i) to (iii) and whose solubility in an alkaline developer is increased by the action of an acid; and
(HR) A positive resist composition containing a resin having at least one of a fluorine atom and a silicon atom, which is different from the resin (B), wherein the amount of the resin (HR) added is The positive resist composition is 0.1 to 10% by mass based on the total solid content of the positive resist composition.

In the formula, X ⁺ represents an organic counter ion, and R represents a hydrogen atom or an organic group represented by the following formula (II).

In the formula (II), Rc represents a monocyclic or polycyclic organic group having 3 to 30 carbon atoms which may contain a cyclic ether, a cyclic thioether, a cyclic ketone, a cyclic carbonate, a lactone or a lactam structure. Y is a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a hydrocarbon group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an acyl having 1 to 10 carbon atoms. Group, a C2-C10 alkoxycarbonyl group, a C2-C10 acyloxy group, a C2-C10 alkoxyalkyl group, or a C1-C8 halogenated alkyl group. When m = 0 to 6 and there are a plurality of Y, they may be the same as or different from each other. n = 1.
(I) The resin (B) contains a repeating unit having a lactone group in which another ring structure is condensed so as to form a bicyclo structure in a 5- to 7-membered ring lactone structure.
(Ii) The resin (B) contains a repeating unit represented by the following general formula (AII).
(Iii) The resin (B) contains two types of repeating units having an acid-decomposable group.

Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.
Ab represents a divalent linking group represented by —Ab ₁ —CO ₂ —.
Ab ₁ represents a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group.
V represents a group having a structure represented by any of the following general formulas (LC1-1) to (LC1-16).

Rb ₂ represents an alkyl group having 1 to 8 carbon atoms, cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a hydroxyl group, It is a cyano group or an acid-decomposable group. n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of substituents Rb ₂ may be the same or different, and a plurality of substituents Rb ₂ may be bonded to form a ring.   2. The positive resist composition according to claim 1, wherein in the general formula (II), Rc represents an adamantyl group. The positive resist composition according to claim 1, wherein the resin ( B ) has a repeating unit represented by the following general formula (AI).

In general formula (AI),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group.
At least two of Rx _{1 to} Rx ₃ may be bonded to form a cycloalkyl group. The resin (B) satisfies the above condition (iii), and at least two of Rx ₁ to Rx _{3 in} the general formula (AI) are bonded to form a monocyclic cycloalkyl group, The positive resist composition according to claim 3. The positive resist composition according to claim 1, wherein the resin (HR) has groups represented by the following general formulas (F2) to (F4).

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, a cycloalkyl group, or an aryl group. However, in each of _{R 57 ~R 61, R 62 ~R} 64 and R ₆₅ to R _68, at least one is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, a cycloalkyl group, Or represents an aryl group.
R ₆₂ and R ₆₃ may be connected to each other to form a ring . The positive resist according to claim 1, wherein the resin (HR) has at least one group selected from the following groups (x) to (z): Composition.
(X) an alkali-soluble group,
(Y) a group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer;
(Z) A group that decomposes by the action of an acid.   The positive resist composition according to claim 1, further comprising two or more mixed solvents containing propylene glycol monomethyl ether acetate as a solvent.   The positive resist composition according to claim 1, further comprising propylene carbonate as a solvent.   A resist film formed from the positive resist composition according to claim 1. A pattern forming method including a step of immersion exposure of the resist film according to claim 9 and a step of developing the resist film.

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