JP2009192617A - Photosensitive composition, pattern forming method using the photosensitive composition and compound used for the photosensitive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition excellent in sensitivity, which ensures good pattern shape in normal exposure (dry exposure) and liquid immersion lithography, to provide a pattern forming method using the photosensitive composition, and to provide a compound used for the photosensitive composition. <P>SOLUTION: The photosensitive composition includes (A) a resin which has a repeating unit (a0) having a sulfonium structure corresponding to a compound represented by a specific general formula, and whose solubility in an alkali developer increases by the action of an acid. The compound for use in the photosensitive composition and the pattern forming method using the photosensitive composition are also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive composition whose properties change upon reaction with actinic rays or radiation, a pattern forming method using the photosensitive composition, and a compound used in the photosensitive composition. More specifically, a photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, a further photofabrication process, a lithographic printing plate, and an acid curable composition, the photosensitive composition The present invention relates to a pattern forming method using a photosensitive composition and a compound used in the photosensitive composition.

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

  In recent years, semiconductor devices have been increasingly densely and highly integrated. Therefore, further fine pattern processing has been required. In order to satisfy this need, the operating wavelength of an exposure apparatus used for photolithography has been increasingly shortened, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. It is becoming. For example, when a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component, and high sensitivity, high resolution, and good A good pattern compared to the conventional naphthoquinonediazide / novolak resin system.

  On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as the exposure light source, the compound having an aromatic group used in the case of KrF essentially exhibits a large absorption in the 193 nm region. An ArF excimer laser resist containing a resin having a highly transparent alicyclic hydrocarbon structure that cannot be used has been developed.

  Examples of the chemically amplified photosensitive composition for ArF excimer laser include, for example, a photosensitive composition containing a (meth) acrylate resin having a structure that decomposes by the action of an acid to generate a carboxylic acid in the side chain and a photoacid generator. Is mentioned. This is because an acid is generated from the photoacid generator by exposure, and a carboxylic acid is generated in the resin side chain by the action of the acid. This carboxylic acid increases the solubility of the photosensitive composition in an alkaline developer, and the exposed area is selectively removed by alkali development to form a fine pattern.

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

Examples of apparatuses in which this effect is applied to the transfer of a fine image pattern of a semiconductor element are introduced in Patent Document 1 (Japanese Patent Laid-Open No. 57-153433), Patent Document 2 (Japanese Patent Laid-Open No. 7-220990), and the like. Yes.
Recent progress in immersion exposure technology is described in Non-Patent Document 1 (SPIE Proc 4688, 11 (2002)), Non-Patent Document 2
(J. Vac. Sci. Tecnol. B 17 (1999)), Non-Patent Document 3 (SPIE Proc 3999, 2 (2000)), Patent Document 3 (International Publication No. 04-077158 pamphlet), etc. . In the case of using an ArF excimer laser as a light source, pure water (refractive index of 1.44 at 193 nm) is considered to be most promising as an immersion liquid in terms of handling safety, transmittance at 193 nm, and refractive index. When an F ₂ excimer laser is used as a light source, a solution containing fluorine has been studied from the balance between transmittance and refractive index at 157 nm. However, a sufficient product has not yet been seen in terms of environmental safety and refractive index. It has not been issued. From the degree of immersion effect and the degree of completeness of the resist, the immersion exposure technique is considered to be installed in the ArF exposure machine earliest.

  In addition, when a chemically amplified resist is applied to immersion exposure, the resist layer comes into contact with the immersion liquid at the time of exposure, so that the resist layer is altered and components that adversely affect the immersion liquid are leached from the resist layer. Has been pointed out. Patent Document 4 (International Publication No. 04-068242 pamphlet) describes an example in which resist performance is changed by immersing a resist for ArF exposure in water before and after exposure, and points to a problem in immersion exposure. Yes.

Various compounds have been found for the photoacid generator which is the main component of the chemically amplified photosensitive composition, and triarylsulfonium salts and arylalkylsulfonium salts (for example, Patent Document 5 (Japanese Patent Laid-Open No. 2000-2000)). No. 275845) and Patent Document 6 (Japanese Patent Laid-Open No. 10-48814) are disclosed.
As the acid to be generated, for example, in Patent Document 7 (Japanese Patent Laid-Open No. 2002-131897), Patent Document 8 (Japanese Patent Laid-Open No. 2003-149812), and Patent Document 9 (Japanese Patent Laid-Open No. 2005-266766), a specific acid is used. Fluorinated organic sulfonic acid is used.

  On the other hand, a photosensitive composition containing a resin having the photoacid generator structure in the side chain is also known, as described in Patent Document 10 (Patent Publication No. 07-0669640).

  However, sufficient resolution performance has not been obtained in some respects.

JP-A-57-153433 JP-A-7-220990 International Publication No. 04-077158 Pamphlet International Publication No. 04-068242 Pamphlet JP 2000-275845 A Japanese Patent Laid-Open No. 10-48814 JP 2002-131897 A JP 2003-149812 A JP 2005-266766 A International Publication No. 07-0669640 Pamphlet SPIE Proc 4688,11 (2002) J.Vac.Sci.Tecnol.B 17 (1999)

  An object of the present invention is to provide a photosensitive composition having good pattern shape and sensitivity not only in normal exposure (dry exposure) but also in immersion exposure, a pattern forming method using the photosensitive composition, and the photosensitivity. It is to provide a compound for use in a composition.

  The present invention is as follows.

[1]
(A) having a repeating unit (a0) having a sulfonium structure S ⁺ (Y ₁ ) (Y ₂ ) (Y ₃ ) corresponding to a compound represented by the following general formula (1), and alkali development by the action of an acid A photosensitive composition comprising a resin having increased solubility in a liquid.

In general formula (1),
Y ₁ , Y ₂ and Y ₃ each independently represents a heterocyclic aromatic group, an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group.
At least one of Y ₁ , Y ₂ and Y ₃ is a heterocyclic aromatic group. At least two of Y ₁ , Y ₂ and Y ₃ may be bonded to each other to form a ring.
At least one of Y ₁ , Y ₂ and Y ₃ has a substituent —A—Y.
A represents a single bond or a divalent organic group.
Y represents a group having a polymerizable group.
Z ⁻ represents a non-nucleophilic anion.
[2]
Z <-> in General formula (1) is chosen from a sulfonate anion, a carboxylate anion, an imido acid anion, or a methide acid anion, The photosensitive composition as described in [1] characterized by the above-mentioned.
[3]
The photosensitive composition as described in [1] or [2], wherein the heteroaromatic group in the general formula (1) has a hetero atom as a sulfur or nitrogen atom.
[4]
The photosensitive composition according to any one of [1] to [3], wherein Y in the general formula (1) is a group having an unsaturated bond capable of radical polymerization.
[5]
Y in the general formula (1) is selected from compounds having one addition-polymerizable unsaturated bond selected from acrylic acid ester, methacrylic acid ester, acrylamide, methacrylamide, allyl, vinyl, vinyl ether, and vinyl ester. The photosensitive composition according to any one of [1] to [3].
[6]
The heterocyclic aromatic group in the general formula (1) is any group selected from a thiophene group, a pyrrole group, an indole group, and a carbazole group. The photosensitive composition as described.
[7]
The sulfonium structure S ⁺ (Y ₁ ) (Y ₂ ) (Y ₃ ) in the general formula (1) is represented by the following general formulas (1a) to (1d) [1] to [6] The photosensitive composition according to any one of the above.

In the general formulas (1a) to (1d),
Ra ₁ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an acyl group.
Ra ₂ and Ra ₃ each independently represents an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group. Ra ₂ and Ra ₃ may be bonded to each other to form a ring.
When there are a plurality of Ra _{4 s} , each independently represents an organic group.
A and Y are synonymous with A and Y in the general formula (1).
m represents an integer of 0 to 3.
[8]
The photosensitive composition according to any one of [1] to [7], further comprising a surface hydrophobized resin (HR).
[9]
Furthermore, (C) The photosensitive composition in any one of [1]-[8] characterized by including the compound which decomposes | disassembles by the effect | action of an acid and generate | occur | produces an acid.
[10]
Resin (A) has a repeating unit which has a structure decomposed | disassembled by the effect | action of an acid, The photosensitive composition in any one of [1]-[9] characterized by the above-mentioned.
[11]
A pattern forming method comprising: forming a photosensitive film from the photosensitive composition according to any one of [1] to [10], and exposing and developing the photosensitive film.
[12]
A step of forming a photosensitive film with the photosensitive composition according to any one of [1] to [10], further forming a surface hydrophobic resin on the upper layer of the photosensitive film, and performing immersion exposure and development. A pattern forming method comprising:
[13]
A pattern forming method comprising: forming a photosensitive film from the photosensitive composition according to any one of [1] to [10], and performing immersion exposure and development on the photosensitive film.
[14]
The compound represented by General formula (1).

In general formula (1),
Y ₁ , Y ₂ and Y ₃ each independently represents a heterocyclic aromatic group, an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group.
At least one of Y ₁ , Y ₂ and Y ₃ is a heterocyclic aromatic group. At least two of Y ₁ , Y ₂ and Y ₃ may be bonded to each other to form a ring.
At least one of Y ₁ , Y ₂ and Y ₃ has a substituent —A—Y.
A represents a single bond or a divalent organic group. Y represents a group having a polymerizable group.
Z ⁻ represents a non-nucleophilic anion.

  Furthermore, the following structures are mentioned as a preferable embodiment of this invention.

  [15] The photosensitive composition according to any one of [1] to [10], further comprising (B) a compound that generates an acid upon irradiation with actinic rays or radiation.

  [16] The photosensitive composition as described in [15], wherein the compound as the component (B) is a sulfonium salt of fluorine-substituted alkanesulfonic acid, fluorine-substituted benzenesulfonic acid or fluorine-substituted imide acid.

  [17] The photosensitive composition as described in any one of [1] to [10], [15] and [16], wherein the resin as the component (A) has a fluorine atom in the main chain or side chain. .

  [18] The photosensitive composition as described in any one of [1] to [10] and [15] to [17], wherein the resin as the component (A) has a hexafluoroisopropanol structure.

  [19] The photosensitive composition as described in any one of [10] [1] to [10] and [15] to [18], wherein the resin as the component (A) has a hydroxystyrene structural unit.

  [20] The resin of component (A) has at least one repeating unit selected from 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate. [1]-[10], [15]-[19] The photosensitive composition as described.

  [21] The photosensitive composition as described in any one of [1] to [10] and [15] to [20], wherein the resin as the component (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure. object.

  [22] The resin of component (A) is at least one repeating unit selected from 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate, at least 1 having a lactone structure The photosensitive composition as described in (15), which has at least one type of repeating unit and at least one type of repeating unit having a hydroxyl group.

  [23] The photosensitive composition as described in any one of [1] to [10] and [15] to [22], wherein the resin as the component (A) further has a repeating unit having a carboxyl group.

  [24] The photosensitive composition as described in any one of [1] to [10] and [15] to [23], wherein the resin as component (A) has a silicon atom in the main chain or side chain.

  [25] The photosensitive composition as described in any one of [1] to [10] and [15] to [24], wherein the resin as the component (A) has a repeating unit having a lactone structure.

  [26] [1] to [10], [15] to [15], further comprising a dissolution inhibiting compound having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer. [25] The photosensitive composition according to any one of [25].

  [27] It further comprises a dissolution inhibiting compound having a molecular weight of 3000 or less, which is decomposed by the action of a resin soluble in an alkali developer and an acid to increase the solubility in the alkali developer [1]. -[10], The photosensitive composition in any one of [15]-[26].

  [28] The photosensitive layer according to any one of [1] to [10] and [15] to [27], further comprising a basic compound and / or fluorine and / or a silicon-based surfactant. Sex composition.

  [29] The basic compound has a compound selected from an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure and a pyridine structure, a hydroxyl group and / or an ether bond. [28] The photosensitive composition according to [28], which is an alkylamine derivative or an aniline derivative having a hydroxyl group and / or an ether bond.

  According to the present invention, a photosensitive composition having a good pattern shape and excellent sensitivity not only in normal exposure (dry exposure) but also in immersion exposure, a pattern forming method using the photosensitive composition, and the photosensitivity Compounds used in the compositions can be provided.

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

(A) Resin whose solubility in an alkaline developer is increased by the action of an acid The photosensitive composition of the present invention is a resin (hereinafter referred to as “resin (A)”) whose solubility in an alkaline developer is increased by the action of an acid. Contain).
In the present invention, (A) a resin whose solubility in an alkaline developer is increased by the action of an acid corresponds to a compound represented by the following general formula (1) (hereinafter sometimes referred to as “compound (1)”). Contains a repeating unit (a0).

In general formula (1),
Y ₁ , Y ₂ and Y ₃ each independently represents a heterocyclic aromatic group, an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group.
At least one of Y ₁ , Y ₂ and Y ₃ is a heterocyclic aromatic group. At least two of Y ₁ , Y ₂ and Y ₃ may be bonded to each other to form a ring.
At least one of Y ₁ , Y ₂ and Y ₃ has a substituent —A—Y.
A represents a single bond or a divalent organic group.
Y represents a group having a polymerizable group.
Z ⁻ represents a non-nucleophilic anion.

In Y ₁ , Y ₂ and Y ₃ in general formula (1), the heterocyclic aromatic group includes an aromatic group having a nitrogen atom, an aromatic group having a sulfur atom, and an aromatic group having an oxygen atom. An aromatic group having a sulfur atom or a nitrogen atom is preferable, an aromatic group having a nitrogen atom is most preferable, and storage stability is improved.

It is desirable that the heterocyclic aromatic group in Y ₁ , Y ₂ and Y ₃ does not have a heteroatom having an unshared electron pair that does not participate in π conjugation. The hetero atom having an unshared electron pair not involved in π conjugation is a hetero atom having a partial structure represented by the following formula, for example.

The partial structure shows basicity, and if the resin (A) has the partial structure, the acid generated by irradiation with actinic rays or radiation is neutralized and the sensitivity is lowered. High sensitivity can be maintained by having no hetero atom.
The number of heteroatoms contained in the heterocyclic aromatic group in Y ₁ , Y ₂ and Y ₃ is preferably 1 to 3, more preferably 1 or 2, particularly preferably 1. .
The heterocyclic aromatic group in Y ₁ , Y ₂ and Y ₃ is preferably an indole structure, a pyrrole structure or a structure in which an aromatic ring is condensed to pyrrole, a thiophene structure or a structure in which an aromatic ring is condensed to thiophene , More preferably a pyrrole group, an indole group, a carbazole group, and a thiophene group, particularly preferably an indole group and a thiophene group, and most preferably an indole group. By using a heterocyclic aromatic group which is an aromatic group having these hetero atoms, the transparency of the resist can be ensured.

The alkyl group in Y ₁ , Y ₂ and Y ₃ is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, for example, 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 Group, octadecyl group, nonadecyl group, eicosyl group and the like.
The cycloalkyl group in Y ₁ , Y ₂ and Y ₃ is preferably a cycloalkyl group having 3 to 20 carbon atoms, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group. And adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetracyclododecyl group, and androstanyl group.
As the aryl group in Y ₁ , Y ₂ and Y ₃ , an aryl group having 6 to 14 carbon atoms is preferable, and examples thereof include a phenyl group and a naphthyl group.
The alkenyl group in Y ₁ , Y ₂ and Y ₃ is preferably an alkenyl group having 2 to 15 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.

At least two of Y ₁ , Y ₂ and Y ₃ may be bonded to each other to form a ring. Examples of the group formed by combining these groups include an alkylene group having 3 to 8 carbon atoms, and the alkylene chain may have an oxygen atom or a sulfur atom.

The aromatic group, alkyl group, cycloalkyl group, aryl group and alkenyl group having a nitrogen atom in Y ₁ , Y ₂ and Y ₃ may further have a substituent. The aromatic group having a nitrogen atom, an alkyl group, a cycloalkyl group, an aryl group, and an alkenyl group may have an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group. , Fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, carboxyl group, nitro group, cyano group, alkoxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, arylcarbonyl group, alkylcarbonyl group, alkenylcarbonyl group, etc. be able to.

At least one of Y ₁ , Y ₂ and Y ₃ has a substituent —A—Y.
A represents a single bond or a divalent organic group.
The divalent linking group represented by A preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms.
Examples of the divalent linking group represented by A include an alkylene group, a cycloalkylene group, an arylene group, and combinations thereof, and the linking group may have an oxygen atom, a nitrogen atom, a sulfur atom, or the like. .
In the compound represented by the general formula (1), when A has a divalent linking group, a product produced by photolysis of a part of the sulfonium group is immediately converted into the light of the remaining undecomposed sulfonium group. Degradation is accelerated and sensitivity is greatly improved.
The divalent linking group represented by A may have a substituent, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, or a cycloalkyl group (preferably having 3 to 10 carbon atoms). ), An aryl group (preferably 6 to 14 carbon atoms), an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), Examples thereof include an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms) and an aminoacyl group (preferably having 2 to 10 carbon atoms). As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms).

Y represents a group having a polymerizable group.
The polymerizable group as Y is preferably a group having an unsaturated bond capable of radical polymerization. Y preferably has 1 to 20 carbon atoms, more preferably 2 to 10 carbon atoms. For example, acrylic acid ester, methacrylic acid ester, acrylamide, methacrylamide, vinyl, a group having an allyl structure, vinyl ether, vinyl ester And a group having a structure having one addition polymerizable unsaturated bond selected from the above. A group having an acrylic acid ester, methacrylic acid ester, acrylamide, methacrylamide, allyl, vinyl or vinyl ester structure having good copolymerization is preferable.

_{Two of} Y ₁ , Y ₂ and Y ₃ may be bonded to A to form an aromatic group having a hetero atom.

The aromatic group having a hetero atom in the compound (1) is an aromatic group having a hetero atom as at least one of Y ₁ , Y ₂ and Y _{3 in} the general formula (1). Alternatively, it may be an aromatic group having a hetero atom formed by the bond between two of Y ₁ , Y ₂ and Y ₃ and A.

一般式（１ａ）〜（１ｄ）に於いて、
Ｒａ_１は、水素原子、アルキル基、シクロアルキル基、アリール基又はアシル基を表す。
Ｒａ_２及びＲａ_３は、各々独立に、アルキル基、シクロアルキル基、アリール基又はアルケニル基を表す。Ｒａ_２及びＲａ_３は、互いに結合して環を形成してもよい。
Ｒａ_４は、複数個ある場合には各々独立に、有機基を表す。
Ａ及びＹは一般式（１）におけるＡ及びＹと同義である。
ｍは０〜３の整数を表す。 The sulfonium structure S ⁺ (Y ₁ ) (Y ₂ ) (Y ₃ ) in the general formula (1) is preferably represented by the following general formulas (1a) to (1d).

In the general formulas (1a) to (1d),
Ra ₁ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an acyl group.
Ra ₂ and Ra ₃ each independently represents an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group. Ra ₂ and Ra ₃ may be bonded to each other to form a ring.
When there are a plurality of Ra _{4 s} , each independently represents an organic group.
A and Y are synonymous with A and Y in the general formula (1).
m represents an integer of 0 to 3.

The alkyl group, cycloalkyl group, aryl group and alkenyl group of Ra ₂ and Ra ₃ are the same as the alkyl group, cycloalkyl group, aryl group and alkenyl group of Y ₁ , Y ₂ and Y _{3 in} the general formula (1). It is the same thing.
Examples of the group formed by combining Ra ₂ and Ra ₃ with each other include an alkylene group having 3 to 8 carbon atoms, and the alkylene chain may have an oxygen atom or a sulfur atom.
The alkyl group of Ra ₁ is preferably a linear or branched alkyl group having 1 to 20 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, Pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl And may be further substituted, and may include an arylalkyl group.
The cycloalkyl group of Ra ₁ is preferably a cycloalkyl group having 3 to 20 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, an adamantyl group, a norbornyl group, an isobornyl group, A camphanyl group, a dicyclopentyl group, an α-pinel group, a tricyclodecanyl group, a tetracyclododecyl group, an androstanyl group, and the like can be given.
The aryl group of Ra ₁ is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.
The acyl group of Ra ₁ is preferably an acyl group having 2 to 20 carbon atoms, and examples thereof include a formyl group, an acetyl group, a propanoyl group, a butanoyl group, a pivaloyl group, and a benzoyl group.
Examples of the organic group for Ra ₄ include an alkyl group (preferably 1 to 20 carbon atoms), a cycloalkyl group (preferably 3 to 20 carbon atoms), an aryl group (preferably 6 to 10 carbon atoms), an alkoxy group ( Preferably 1 to 20 carbon atoms), acyl group (preferably 2 to 20 carbon atoms), acyloxy group (preferably 2 to 20 carbon atoms), fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, carboxyl group, Examples thereof include a nitro group, a cyano group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an arylcarbonyl group, an alkylcarbonyl group, and an alkenylcarbonyl group.
m represents an integer of 0 to 3, preferably 0 to 2, and more preferably 0 to 1.

  Hereinafter, although the specific example of a cation part in the compound represented by General formula (1) is given, this invention is not limited to this.

In the general formula (1), the non-nucleophilic anion represented by Z ⁻ is an organic anion or an inorganic anion, more preferably an organic anion having a carbon atom, and still more preferably a monovalent or divalent organic anion. Anion.
Specific examples of the non-nucleophilic anion represented by Z ⁻ include sulfonate anion, carboxylate anion, imido acid anion, methide acid anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. May include a sulfonate anion, a carboxylic acid anion, an imido acid anion, or a methide acid anion.

Preferable monovalent non-nucleophilic anions represented by Z ⁻ include non-nucleophilic organic anions represented by the following structural formula.

In the above structural formula,
Rb ₁ represents an organic group. The organic group represented by rb _1, preferably an organic group having 1 to 30 carbon atoms, e.g., alkyl group, cycloalkyl group, aryl group, or a plurality of these, a single bond, -O -, - CO ₂ -, - S -, - SO 3 -, - SO 2 N (Rc 1) - can be exemplified linked group a linking group such as. In the formula, Rc ₁ represents a hydrogen atom or an alkyl group.
Rb ₃ , Rb ₄ and Rb ₅ each independently represents an organic group. The organic group of Rb _3, Rb ₄ and Rb ₅ may be the same as the organic group of Rb _1, particularly preferably a perfluoroalkyl group having 1 to 4 carbon atoms.
Rb ₃ and Rb ₄ may be bonded to form a ring. Examples of the group formed by combining Rb ₃ and Rb ₄ include an alkylene group and an arylene group, and a perfluoroalkylene group having 2 to 4 carbon atoms is preferable.
The organic group of Rb ₁ and Rb _{3 to} Rb ₅ is preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.
Of the above structural formulas, (Z-1), (Z-3), and (Z-4) are most preferred, and this improves solvent solubility and sensitivity.

Z ^- include non-nucleophilic organic anions represented by the following structural formula as a non-nucleophilic anion preferably divalent represents.

In the above structural formula, Rb ₃ and Rb ₄ has the same meaning as Rb ₃ and Rb ₄ to a monovalent non-nucleophilic organic anion.
Rb ₂ represents a divalent linking group. Preferred examples of the divalent linking group for Rb ₂ include those in which one hydrogen atom is removed from the organic group in Rb ₁ to form a divalent linking group.

  Hereinafter, although the specific example of an anion part in the compound represented by General formula (1) is shown, this invention is not limited to this.

  Specific examples of the compound represented by the general formula (1) are listed in Table 1 below, but the present invention is not limited thereto.

Compound (1) is a novel compound.
Compound (1) is a heteroaromatic compound such as indole as described in Tetrahedron, 44 (11), 3261-3270, 1988 and J. Heterocycl. Chem., 30 (3), 617-622, 1993. A sulfonium skeleton is formed by reacting a compound with a sulfoxide compound such as diphenyl sulfoxide and tetramethylene sulfoxide in the presence of an acid condition or an activator such as an acid anhydride, and then, Japanese Patent Laid-Open No. 11-501909 or It can be easily synthesized using a salt exchange method with any anion described in No. 246786.

The content of the repeating unit (a0) having a sulfonium structure S ⁺ (Y ₁ ) (Y ₂ ) (Y ₃ ) corresponding to the compound represented by the general formula (1) is the total repeating unit in the resin (A). On the other hand, 1-60 mol% is preferable, More preferably, it is 1-50 mol%, More preferably, it is 5-40 mol%.

In the photosensitive composition of the present invention, the resin of component (A) is a group that decomposes into the main chain or side chain of the resin, or both of the main chain and side chain by the action of an acid to generate an alkali-soluble group ( Hereinafter, it is preferable to have a repeating unit having an “acid-decomposable group”.
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 resin of component (A) preferably has a repeating unit having an acid-decomposable group. The repeating unit having an acid-decomposable group 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 (straight or branched) or a cycloalkyl group (monocyclic or polycyclic).
At least two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).

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 is preferably an alkyl group having 1 to 4 carbon atoms 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.
Examples of the cycloalkyl group represented by Rx _{1 to} Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, polycyclic cycloalkyl groups such as norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. Groups 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 content of the repeating unit which has an acid-decomposable group, 20-50 mol% is preferable with respect to all the repeating units in a polymer, 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.

  The resin of component (A) 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 resin of component (A) preferably has a repeating unit having a lactone group.
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. Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent linking group obtained by combining these. Good film is a single bond, -Ab ₁ -CO ₂ - is a divalent linking group represented by. Ab ₁ is a linear, branched allene 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 polymer.

  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 the optimum lactone group, the pattern profile and the density dependence become good.

  The resin of component (A) 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 an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 with respect to all repeating units in the polymer. ˜25 mol%.

  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 (A) 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 content of the repeating unit which has an alkali-soluble group, 1-20 mol% is preferable with respect to all the repeating units in a polymer, 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 (A) may further have a repeating unit having an alicyclic hydrocarbon structure and not exhibiting 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 (A) includes 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.

Thereby, the performance required for the resin of component (A), in particular,
(1) Solubility in coating solvent
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Fine adjustment such as dry etching resistance can be performed.

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

  As the resin of component (A), 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 containing 0 to 30 mol% of a (meth) acrylate-based repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and further containing 0 to 20 mol% of another (meth) acrylate-based repeating unit. .

  When the photosensitive composition of the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, or high energy light beam (EUV, etc.) having a wavelength of 50 nm or less, the resin of component (A) is represented by the general formula (AI) In addition to the repeating unit represented by the formula, it is preferable to further have a hydroxystyrene-based repeating unit. More preferably, it has a hydroxystyrene-based repeating unit, a hydroxystyrene-based repeating unit protected with an acid-decomposable group, and an acid-decomposable repeating unit such as a (meth) acrylic acid tertiary alkyl ester.

  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 (A) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and 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 photosensitive composition of the present invention. Thereby, the generation of particles during storage can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As 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 ° C to 100 ° C.

The weight average molecular weight of the component (A) 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. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, or viscosity is increased and film forming property is deteriorated. Can be prevented.
The degree of dispersion (molecular weight distribution) is usually 1 to 3, preferably 1 to 2, and more preferably 1.1 to 2.5. 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 photosensitive composition of the present invention, the blending amount of the resin as the component (A) in the entire composition is preferably 0.1 to 99% by mass based on the total solid content of the resist composition. Preferably it is 0.2-50 mass%.
In the present invention, the resin of component (A) may be used alone or in combination.

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

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

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

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

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

In 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, boronyl group and the like.

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

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Among acid generators, particularly preferred examples are given below.

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

(C) Compound represented by general formula (I) that decomposes by the action of an acid to generate an acid The photosensitive composition of the present invention is decomposed by the action of an acid represented by the following general formula (I) And a compound capable of generating an acid (hereinafter also referred to as “acid proliferating agent”).

In general formula (I),
R ₁ represents an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group or an aryloxy group.
R ₂ represents an alkyl group or a cycloalkyl group.
R ₁ and R ₂ may combine to form a monocyclic or polycyclic hydrocarbon structure.
R ₃ and R ₄ each independently represents a hydrogen atom or an alkyl group.
R ₅ represents a group capable of leaving by the action of an acid.
X is, -SO ₂ -, - SO- or an -CO-.
Z represents a residue of an organic acid represented by ZH.

In the general formula (I), the alkyl group represented by R ₁ , R ₂ , R ₃ and R ₄ is preferably an alkyl group having 1 to 8 carbon atoms, specifically a methyl group, an ethyl group or a propyl group. Isopropyl group, butyl group, octyl group and the like.
As the cycloalkyl group for R ₁ and R _2, a cycloalkyl group having 4 to 10 carbon atoms is preferable, and specifically, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, an adamantyl group, a boronyl group, Examples include an isobornyl group, a tricyclodecanyl group, a dicyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, and a tetracyclododecanyl group.
The alkoxy group of R ₁ is preferably a linear or branched alkoxy group having 1 to 30 carbon atoms, such as methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group. T-butoxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like.
The aryl group of R ₁ is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.
The aryloxy group for R ₁ is preferably an aryloxy group having 6 to 20 carbon atoms, and examples thereof include a phenoxy group.
The monocyclic or polycyclic cyclic hydrocarbon structure formed by combining R ₁ and R ₂ is preferably a cyclic hydrocarbon structure having 3 to 15 carbon atoms, such as a cyclopentanone structure, a cyclohexanone structure, a norbornanone structure, A cyclic hydrocarbon structure having an oxo group such as an adamantanone structure can be given.
Each of the above groups may have a substituent. Examples of the substituent that each of the above groups may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a cycloalkyl group (preferably having 3 to 20 carbon atoms), and an aryl group (preferably carbon). Number 6 to 14), an alkoxy group (preferably 1 to 20 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 20 carbon atoms), and the like. As for the group having a cyclic structure such as a cycloalkyl group or an aryl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20).

Examples of the group capable of leaving by the action of an acid of R ₅ include groups represented by the following general formula (pI) to general formula (pV), and include monocyclic or polycyclic alicyclic hydrocarbon structures. A group having

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

In the general formulas (pI) to (pV), the alkyl group of R _{11 to} R ₂₅ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, n -Propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like can be mentioned.
The cycloalkyl group or the cycloalkyl group formed by Z and the carbon atom in R _{12 to} R ₂₅ may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25.
Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.
These alkyl groups and cycloalkyl groups may have a further substituent. As further substituents of these alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers) 2-6). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The organic acid of ZH is preferably sulfonic acid, carboxylic acid, imide acid, or methide acid.

  Z is preferably a group represented by the following structural formula.

In the above structural formula,
Rb ₁ represents an organic group. The organic group of Rb ₁ is preferably an organic group having 1 to 30 carbon atoms. For example, an alkyl group, a cycloalkyl group, an aryl group, or a plurality of these are a single bond, —O—, —CO ₂ —, —S. Examples include groups linked by a linking group such as —, —SO ₃ —, and —SO ₂ N (Rc ₁ ) —. In the formula, Rc ₁ represents a hydrogen atom or an alkyl group.
Rb ₃ , Rb ₄ and Rb ₅ each independently represents an organic group. The organic group of Rb _3, Rb ₄ and Rb ₅ may be the same as the organic group of Rb _1, particularly preferably a perfluoroalkyl group having 1 to 4 carbon atoms.
Rb ₃ and Rb ₄ may be bonded to form a ring. Examples of the group formed by combining Rb ₃ and Rb ₄ include an alkylene group and an arylene group, and a perfluoroalkylene group having 2 to 4 carbon atoms is preferable.
The organic group of Rb ₁ and Rb _{3 to} Rb ₅ is preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.

  The general formula (I) is preferably the following general formula (Ia) or (Ib).

In general formulas (Ia) and (Ib):
R ₁ represents an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group or an aryloxy group.
R ₂ represents an alkyl group or a cycloalkyl group.
R ₁ and R ₂ may combine to form a monocyclic or polycyclic hydrocarbon structure.
R ₃ and R ₄ each independently represents a hydrogen atom or an alkyl group.
X is, -SO ₂ -, - SO- or an -CO-.
Z represents a residue of an organic acid represented by ZH.
Ry _{1 to} Ry ₃ each independently represents an alkyl group or a cycloalkyl group. At least two of Ry _{1 to} Ry ₃ may combine to form a monocyclic or polycyclic hydrocarbon structure. However, at least one of Ry _{1 to} Ry ₃ represents a cycloalkyl group, or at least two of Ry _{1 to} Ry ₃ are bonded to form a monocyclic or polycyclic cyclic hydrocarbon structure. .
Ry ₄ represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Ry ₅ represents a cycloalkyl group.
Ry ₄ and Ry ₅ may combine to form a monocyclic or polycyclic hydrocarbon structure.

In formula (Ia) and _{(Ib), R 1 ~R 4} , X and Z are in the general formula (I), the same meanings as R ₁ to R _4, X and Z.
The alkyl group of Ry _{1 to} Ry ₄ may be either a linear alkyl group or a branched alkyl group, and may have a substituent. Preferred linear and branched alkyl groups have 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl groups. And preferably a methyl group or an ethyl group.
Examples of the cycloalkyl group of Ry _{1 to} Ry ₅ include a monocyclic cycloalkyl group having 3 to 8 carbon atoms and a polycyclic cycloalkyl group having 7 to 14 carbon atoms, and has a substituent. Also good. Preferred examples of the monocyclic cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cyclopropyl group. Preferred examples of the polycyclic cycloalkyl group include an adamantyl group, a norbornane group, a tetracyclododecanyl group, a tricyclodecanyl group, and a diamantyl group.
The monocyclic hydrocarbon structure formed by combining at least two members out of Ry _{1 to} Ry ₃ is preferably a cyclopentane structure or a cyclohexane structure. The polycyclic hydrocarbon structure formed by combining at least two of Ry _{1 to} Ry ₃ is preferably an adamantane structure, a norbornane structure, or a tetracyclododecane structure.
Examples of the monocyclic or polycyclic hydrocarbon structure formed by combining Ry ₄ and Ry ₅ include a tetramethylene oxide ring structure, a pentamethylene oxide ring structure, and a hexamethylene oxide ring structure. .
Each of the above groups may have a substituent. Examples of the substituent that each of the above groups may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a cycloalkyl group (preferably having 3 to 20 carbon atoms), and an aryl group (preferably carbon). Number 6 to 14), an alkoxy group (preferably 1 to 20 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 20 carbon atoms), and the like. As for the group having a cyclic structure such as a cycloalkyl group or an aryl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20).

The compound represented by general formula (I) that decomposes by the action of an acid to generate an acid is a novel compound.
The compound represented by the general formula (I) that decomposes and generates an acid by the action of an acid is first a method of condensing an ester compound under a basic condition or a method of reacting an alcohol with a diketene (Synthesis, 1989, 387). -388), or by reacting acetoacetate with chloromethyl ether, and then synthesizing an α-substituted acetate which is an active methylene compound, J. Am. Chem. Soc. 1998, 120, 37-45 Can be synthesized by sequentially performing monoalkylation of active methylene and hydroxymethylation of active methylene, followed by reaction with sulfonic acid chloride under a base.

  Hereinafter, although the specific example of an acid growth agent is given, this invention is not limited to this.

  The content of the acid proliferating agent in the photosensitive composition of the present invention is preferably 0.1 to 20.0 mass%, more preferably 0.1 to 10.0 mass%, based on the solid content of the composition. is there.

Solvents Solvents that can be used when preparing the photosensitive composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, lactate alkyl esters, and alkoxypropionate alkyls. And organic solvents such as cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds which may contain rings (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates and alkyl pyruvates. it can.

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

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

  Examples of the cyclic lactone 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 that 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.

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

In general formulas (A) to (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring.

About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
The alkyl groups in these general formulas (A) to (E) are more preferably unsubstituted.

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

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, 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. ] Undec-7-ene. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, tris (methoxyethoxyethyl) amine, N-phenyldiethanolamine and the like. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

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

These basic compounds are used alone or in combination of two or more.
The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of solid content of a positive resist composition, Preferably it is 0.01-5 mass%.

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

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

When the photosensitive composition of the present invention contains the above-mentioned surfactant, it provides a resist pattern with less sensitivity and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. Is 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 F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189 , F113, F110, F177, F120, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei 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, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, the copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

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

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

  These surfactants may be used alone or in several combinations.

  The amount of the surfactant used is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on the total amount of the photosensitive composition (excluding the solvent).

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

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

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

  The content of the carboxylic acid onium salt in the composition is 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. %.

Dissolution-inhibiting compound having a molecular weight of 3000 or less that decomposes by the action of an acid to increase the solubility in an alkali developer. Dissolution-inhibiting compound having a molecular weight of 3000 or less that decomposes by the action of an acid to increase the solubility in an alkali developer. (Hereinafter, also referred to as “dissolution inhibitor compound”), such as a cholic acid derivative containing an acid-decomposable group described in ProceedingofSPIE, 2724,355 (1996), in order not to lower the permeability of 220 nm or less. An alicyclic or aliphatic compound containing an acid-decomposable group is preferred. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the component (A) resin.

  When exposing the photosensitive composition of this invention with a KrF excimer laser, or irradiating with an electron beam, what contains the structure which substituted the phenolic hydroxyl group of the phenol compound by the acid-decomposable group is preferable. 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 solid content of the photosensitive composition.

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

Other Additives In the photosensitive composition of the present invention, a dye, a plasticizer, a photosensitizer, a light absorber, and a compound that promotes solubility in a developer (for example, a molecular weight of 1000 or less) are included in the photosensitive composition of the present invention. A phenol compound, an alicyclic compound having a carboxyl group, or an aliphatic compound).

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.

Pattern Formation Method The photosensitive composition of the present invention is preferably used at a film thickness of 30 to 250 nm, more preferably at a film thickness of 30 to 200 nm, from the viewpoint of improving resolution. Such a film thickness can be obtained by setting the solid content concentration in the photosensitive 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 photosensitive 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 photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the above mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

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

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 1. Far ultraviolet light having a wavelength of 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ Excimer laser, EUV (13 nm), and electron beam are preferable.

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

  Exposure (immersion exposure) may be performed by filling a liquid (an immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred.

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist 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 is desirably 18.3 MQcm or more, the TOC (organic substance concentration) is desirably 20 ppb or less, and deaeration treatment is desirably performed.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive for increasing the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

When the resist film made of the photosensitive composition of the present invention is exposed through an immersion medium, a hydrophobic resin (HR) can be further added as necessary. As a result, hydrophobic resin (HR) is unevenly distributed on the surface of the resist film, and when the immersion medium is water, the receding contact angle of the resist film surface with respect to the water when used as a resist film is improved, and the followability of immersion water is improved. Can be made. As the hydrophobic resin (HR), any resin can be used as long as the receding contact angle on the surface can be improved by adding it, but a resin having at least one of a fluorine atom and a silicon atom is preferable. The receding contact angle of the resist film is preferably 60 ° to 90 °, more preferably 70 ° or more. The addition amount can be adjusted 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 photosensitive composition. 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 in a dynamic state. 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. Generally, it can be measured using a contact angle measurement method 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 becomes important, and the resist is required to have the capability of following the high-speed scanning of the exposure head without leaving 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 or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having a carbon number of 1 ~ 4). 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.

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 a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. As the divalent linking group, an alkylene group, a phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a urea group is used alone or in combination of two or more groups. A combination is mentioned.
n represents an integer of 1 to 5.

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

Furthermore, the hydrophobic resin (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 group having 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. It is preferable to use a repeating unit in which an alkali-soluble group is bonded to the chain, and further introduce a polymerization initiator or chain transfer agent having an alkali-soluble group at the end of the polymer chain at the time of polymerization.
The content of the repeating unit having an alkali-soluble group (x) is preferably from 1 to 50 mol%, more preferably from 3 to 35 mol%, still more preferably from 5 to 20 mol%, based on all repeating units in the polymer.

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

(Y) Examples of the group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer include a group having a lactone structure, an acid anhydride, an acid imide group, and the like, and preferably a lactone group It is.
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 (A).

  In the hydrophobic resin (HR), examples of the repeating unit having a group (z) that is decomposed by the action of an acid are the same as the repeating unit having an acid-decomposable group listed for the resin of the component (A). . 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.

  The hydrophobic resin (HR), like the resin of the component (A), naturally has few impurities such as metals, and the residual monomer or oligomer component is preferably 0 to 10% by mass, more preferably. 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 photosensitive composition of the present invention. Thereby, the generation of particles during storage can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As 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 contacted to precipitate a resin (step a), the resin is separated from the solution (step b), and dissolved again in the solvent to obtain a resin solution A. (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. The following table shows the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), weight average molecular weight, and degree of dispersion.

In order to prevent the photosensitive film from coming into direct contact with the immersion liquid between the photosensitive film of the photosensitive composition of the present invention and the immersion liquid, an immersion liquid hardly soluble film (hereinafter referred to as “topcoat”) is also used. May be provided). The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the top coat is preferably a polymer that does not contain abundant aromatics. Specifically, the polymer contains a hydrocarbon polymer, an acrylate polymer, polymethacrylic acid, polyacrylic acid, polyvinyl ether, and silicon. Examples thereof include a polymer and a fluorine-containing polymer. The aforementioned hydrophobic resin (HR) is also suitable as a top coat. From the viewpoint of contaminating the optical lens when impurities are eluted from the top coat into the immersion liquid, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

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

  The top coat is preferably not mixed with the photosensitive film and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, the solvent used for the topcoat is preferably a non-water-soluble medium that is hardly soluble in the solvent used for the photosensitive composition. Furthermore, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

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

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

[Synthesis example]
Synthesis Example of Compound A-12 10.0 g (85.4 mmol) of Indol and 13.0 g (85.4 mmol) of 4-Chloromethylstyrene were dissolved in 100 mL of DMF and cooled with ice, and then potassium butoxide (Potassium tert. -Butoxide) 11.5 g (102.5 mmol) was added. The mixture was stirred for 0.5 hour under ice-cooling, and further stirred at 50 ° C. for 2 hours. 200 mL of ethyl acetate was added, the organic layer was washed successively with saturated brine twice and water twice, the organic layer was dried over sodium sulfate, and a brown oil 1- (4-vinylbenzyl) -1H-indole ( 1- (4-vinylbenzyl) -1H-indole) 22.0 g was obtained. 7.00 g (30 mmol) of this brown oil and 6.25 g (60 mmol) of tetramethylene sulfoxide were dissolved in 80 mL of chloroform, and this was cooled to −30 ° C. under a nitrogen stream. To this solution, 18.9 g (90 mmol) of trifluoroacetic anhydride was added dropwise over 0.5 hours. The mixture was warmed to room temperature and reacted for 1 hour. To this was added 30.4 g (90 mmol) of potassium nonafluorobutanesulfonate in 100 mL of acetonitrile / 20 mL of water. After stirring for 3 hours, the chloroform phase was washed with water and concentrated to obtain the desired brown oil (18.9 g).
¹ H-NMR (400 MHz, CDCl ₃ ) δ 2.49 (m, 2H), 2.77 (m, 2H), 3.71 (m, 2H), 4.05 (m, 2H), 5.25 (d, 1H), 5.71 (d , 1H), 6.67 (m, 1H), 7.20-7.22 (m, 2H), 7.32-7.38 (m, 4H), 7.45-7.47 (m, 1H), 7.62-7.64 (m, 1H), 8.37 (s , 1H)
19F-NMR (400 MHz, CDCl ₃ ) δ -126 (s, 2F), -122 (s, 2F), -115 (s, 2F), -81 (s, 3F)

  Other compounds represented by the general formula (1) were synthesized in the same manner.

Polymer Synthesis Example Synthesis of Resin (P-1) Under a nitrogen stream, 12.39 g of propylene glycol monomethyl ether acetate was placed in a three-necked flask and heated to 80 ° C. To this, 6.69 g of norbornane lactone methacrylate, 2.37 g of 3-hydroxyadamantyl methacrylate, 7.31 g of 1-ethylcyclopentyl methacrylate, 12.43 g of compound (A-12), 406 mg of 1-dodecanethiol, initiator V- A solution prepared by dissolving 498 mg of 65 (manufactured by Wako Pure Chemical Industries, Ltd.) in 111.5 g of propylene glycol monomethyl ether acetate was added dropwise over 6 hours. After completion of the 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 methanol 1400 ml / water 100 ml over 20 minutes. The precipitated powder was collected by filtration and dried to obtain 20.9 g of Resin (P-1). The weight average molecular weight of the obtained resin was 13500 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.4.

Synthesis of Resin (P-6) Under a nitrogen stream, 4.10 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 4-oxa-5-oxo-6-cyanotricyclo [4.2.1.0 <3.7>] non-2-yl 2-methylprop-2-enoate (4-oxa-5-oxo-6-cyanotricyclo [4.2 .1.0 <3.7>] non-2-yl 2-methylprop-2-enoate) 9.92 g, 3,5-dihydroxy-1-adamantyl 2-methylprop-2-enoate 2- methylprop-2-enoate) 2.53 g, cyclohexylpropan-2-yl methacrylate 8.44 g, compound (A-12) 6.21 g, initiator V-601 (manufactured by Wako Pure Chemical) A solution prepared by dissolving 1.85 g in 36.9 g of cyclohexanone was added dropwise over 6 hours. After completion of the 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 1000 ml of hexane / 100 ml of ethyl acetate over 20 minutes, and the precipitated powder was collected by filtration. The obtained powder was dissolved in 100 ml of methyl ethyl ketone and dropped into a mixed solution of 1000 ml of methanol / 100 ml of water over 20 minutes, and the precipitated powder was collected by filtration. When dried, 10.5 g of Resin (P-6) was obtained. The weight average molecular weight of the obtained resin was 5600 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.4.

  Other resins were synthesized in the same manner.

  Regarding the resins (P-1) to (P-25) of the component (A) used in the examples, the monomers, composition ratios, weight average molecular weights, and dispersities used in the respective synthesis are shown in Table 3 below.

Examples 1-25 and Comparative Examples 1-5
<Resist preparation>
The components shown in Table 4 below were dissolved in a solvent, and a solution with a solid content of 5% by mass was prepared for each, and this was filtered through a 0.1 μm polyethylene filter to prepare a photosensitive composition. The prepared photosensitive composition was evaluated by the following method, and the results are shown in Table 4. About each component in a table | surface, ratio when using multiple is mass ratio.
In Table 4, when the photosensitive composition contained a hydrophobic resin (HR), the addition form was marked as “addition”. When the photosensitive composition does not contain a hydrophobic resin (HR) and a topcoat protective film containing a hydrophobic resin (HR) is formed on the upper layer after forming a photosensitive film, the addition form is expressed as “ TC ".

Image performance test (Exposure conditions (1) Normal dry exposure)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The positive resist composition prepared thereon was applied and baked at 130 ° C. for 60 seconds to form a 120 nm resist film. Using the obtained wafer ArF excimer laser scanner (manufactured by ASML, PAS5500 / 1100, NA0.75), the film was exposed through a 6% halftone mask with a 65 nm 1: 1 line and space pattern. Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.

(Exposure conditions (2) Normal immersion exposure)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The positive resist composition prepared thereon was applied and baked at 130 ° C. for 60 seconds to form a 120 nm resist film. The obtained wafer was exposed through a 6% halftone mask having a 65 nm 1: 1 line and space pattern using an ArF excimer laser immersion scanner (PAS5500 / 1250i, NA0.85, manufactured by ASML). Ultra pure water was used as the immersion liquid. Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.

When the addition form of the surface hydrophobizing resin (HR) was “TC”, the following operation was performed after forming the resist film.
<Method for forming topcoat layer>
On the resist film, a surface hydrophobized resin (HR) shown in Table 5 was dissolved in a solvent, applied with a spin coater, and the wafer was heated and dried at 115 ° C. for 60 seconds to form a 0.05 μm top coat layer. At this time, the top coat application unevenness was observed, and it was confirmed that it was uniformly applied without application unevenness.
Abbreviations for solvents are as follows.
SL-1; 2-ethylbutanol SL-2; perfluorobutyltetrahydrofuran

sensitivity:
The exposure amount (mJ / cm ² ) at which the 1: 1 line and space pattern was resolved was defined as sensitivity. A smaller value indicates better performance.

Pattern shape:
The exposure amount that reproduces a line-and-space 1/1 with a mask size of 130 nm was taken as the optimal exposure amount, and the profile at the optimal exposure amount was observed with a scanning electron microscope (SEM).

  The symbols in the table are as follows.

[Basic compounds]
TPI: 2,4,5-triphenylimidazole TPSA: triphenylsulfonium acetate DIA: 2,6-diisopropylaniline DCMA: dicyclohexylmethylamine TPA: tripentylamine TBAH: tetrabutylammonium hydroxide TMEA: tris (methoxyethoxyethyl) Amine PEA: N-phenyldiethanolamine TOA: Trioctylamine DBN: 1,5-diazabicyclo [4.3.0] non-5-ene PBI: 2-phenylbenzimidazole
DHA: N, N-dihexylaniline

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF656 (manufactured by OMNOVA, fluorine-based)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)

〔solvent〕
A1: Propylene glycol monomethyl ether acetate A2: 2-heptanone A3: Cyclohexanone A4: γ-Butyrolactone B1: Propylene glycol monomethyl ether B2: Ethyl lactate B3: Propylene carbonate

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

  From the results in Table 4, it can be seen that the photosensitive composition of the present invention has good pattern shape and sensitivity not only in normal exposure (dry exposure) but also in immersion exposure.

Claims (14)

(A) having a repeating unit (a0) having a sulfonium structure S ⁺ (Y ₁ ) (Y ₂ ) (Y ₃ ) corresponding to a compound represented by the following general formula (1), and alkali development by the action of an acid A photosensitive composition comprising a resin having increased solubility in a liquid.

In general formula (1),
Y ₁ , Y ₂ and Y ₃ each independently represents a heterocyclic aromatic group, an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group.
At least one of Y ₁ , Y ₂ and Y ₃ is a heterocyclic aromatic group. At least two of Y ₁ , Y ₂ and Y ₃ may be bonded to each other to form a ring.
At least one of Y ₁ , Y ₂ and Y ₃ has a substituent —A—Y.
A represents a single bond or a divalent organic group.
Y represents a group having a polymerizable group.
Z ⁻ represents a non-nucleophilic anion.   2. The photosensitive composition according to claim 1, wherein Z − in the general formula (1) is selected from a sulfonate anion, a carboxylate anion, an imido acid anion, or a methide acid anion.   The photosensitive composition according to claim 1 or 2, wherein the heteroaromatic group in the general formula (1) has a hetero atom which is a sulfur or nitrogen atom.   The photosensitive composition according to claim 1, wherein Y in the general formula (1) is a group having an unsaturated bond capable of radical polymerization.   Y in the general formula (1) is selected from compounds having one addition polymerizable unsaturated bond selected from acrylic acid ester, methacrylic acid ester, acrylamide, methacrylamide, allyl, vinyl, vinyl ether, vinyl ester. The photosensitive composition according to any one of claims 1 to 3.   The heterocyclic aromatic group in the general formula (1) is any group selected from a thiophene group, a pyrrole group, an indole group, and a carbazole group. Photosensitive composition. The sulfonium structure S ⁺ (Y ₁ ) (Y ₂ ) (Y ₃ ) in the general formula (1) is represented by the following general formulas (1a) to (1d): The photosensitive composition in any one of 6.

In the general formulas (1a) to (1d),
Ra ₁ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an acyl group.
Ra ₂ and Ra ₃ each independently represents an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group. Ra ₂ and Ra ₃ may be bonded to each other to form a ring.
When there are a plurality of Ra _{4 s} , each independently represents an organic group.
A and Y are synonymous with A and Y in the general formula (1).
m represents an integer of 0 to 3.   The photosensitive composition according to claim 1, further comprising a surface hydrophobizing resin (HR).   The photosensitive composition according to claim 1, further comprising (C) a compound capable of decomposing by the action of an acid to generate an acid.   Resin (A) has a repeating unit which has a structure decomposed | disassembled by the effect | action of an acid, The photosensitive composition in any one of Claims 1-9 characterized by the above-mentioned.   A pattern forming method comprising forming a photosensitive film from the photosensitive composition according to claim 1, and exposing and developing the photosensitive film.   A process comprising forming a photosensitive film from the photosensitive composition according to claim 1, further forming a surface hydrophobic resin on the photosensitive film, immersion exposure, and developing. A pattern forming method characterized by the above.   A pattern forming method comprising: forming a photosensitive film from the photosensitive composition according to claim 1, and subjecting the photosensitive film to immersion exposure and development. The compound represented by General formula (1).

In general formula (1),
Y ₁ , Y ₂ and Y ₃ each independently represents a heterocyclic aromatic group, an alkyl group, a cycloalkyl group, an aryl group or an alkenyl group.
At least one of Y ₁ , Y ₂ and Y ₃ is a heterocyclic aromatic group. At least two of Y ₁ , Y ₂ and Y ₃ may be bonded to each other to form a ring.
At least one of Y ₁ , Y ₂ and Y ₃ has a substituent —A—Y.
A represents a single bond or a divalent organic group. Y represents a group having a polymerizable group.
Z ⁻ represents a non-nucleophilic anion.