JP2009069630A - Photosensitive composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition for use in the production process of a semiconductor such as IC, in the production of a circuit substrate of liquid crystal, thermal head and the like or in other photofabrication processes, which has improved sensitivity, resolution, line edge roughness and pattern collapse, and to provide a pattern forming method using the same. <P>SOLUTION: The photosensitive composition comprises (A) a polymer which includes a repeating unit having a specific acetal structure and a repeating unit having another specific acetal structure and decomposes under an action of an acid to increase solubility in an alkali developer, and (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation. The pattern forming method uses this photosensitive composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive composition that can be suitably used for manufacturing semiconductor integrated circuit elements, integrated circuit manufacturing masks, printed wiring boards, liquid crystal panels, and the like, and a pattern forming method using the same.

  As the photosensitive composition, there is a chemically amplified photosensitive composition. The chemically amplified photosensitive composition generates an acid in an exposed area by irradiation with actinic light or radiation such as far ultraviolet light, and a reaction using this acid as a catalyst to react an active light or radiation irradiated part with a non-irradiated part. It is a pattern forming material for changing the solubility in a developer to form a pattern on a substrate.

As a chemically amplified photosensitive composition, Japanese Patent Application Laid-Open No. 2-19847 [Patent Document 1] discloses a resin in which the phenolic hydroxyl groups of poly (p-hydroxystyrene) are completely or partially protected with tetrahydropyranyl groups. There is disclosed a photoresist composition characterized by containing.
Similarly, JP-A-4-219757 [Patent Document 2] is characterized by containing a resin in which 20 to 70% of the phenolic hydroxyl groups of poly (p-hydroxystyrene) are substituted with acetal groups. A photoresist composition is disclosed.
Further, JP-A-5-249682 [Patent Document 3] discloses a photoresist composition using a similar acetal-protected resin.
JP-A-8-123032 [Patent Document 4] discloses a photoresist composition using a terpolymer containing a group substituted with an acetal group.
Further, JP-A-5-113667 [Patent Document 5], JP-A-6-266112 [Patent Document 6], JP-A-6-289608 [Patent Document 7], JP-A-7-209868 [Patent Document 6]. Reference 8] discloses a photoresist composition comprising hydroxystyrene and a (meth) acrylate copolymer.
JP-A-9-297396 [Patent Document 9] discloses a polymer having a group that can be decomposed by an acid, a radiation-sensitive acid generator, and a phenolic hydroxyl group in a compound having a phenolic hydroxyl group and a molecular weight of less than 1000. A photosensitive resin composition containing a compound obtained by acetalizing a hydrogen atom and an acid diffusion control material is described. It is described that this composition is excellent in resolving power of contact holes, cross-sectional shape, and focus tolerance.
However, the conventional chemical amplification type photosensitive composition has not necessarily achieved sufficient results in four points of sensitivity, resolution, line edge roughness, and pattern collapse.

JP-A-2-19847 JP-A-4-219757 JP-A-5-249682 JP-A-8-123032 JP-A-5-113667 JP-A-6-266112 JP-A-6-289608 JP-A-7-209868 JP-A-9-297396

  An object of the present invention is to provide a photosensitive composition improved in four points of sensitivity, resolution, line edge roughness and pattern collapse, and a pattern forming method using the same.

  The present invention has the following configuration.

  (1) (A) It has a repeating unit represented by the following general formula (I) and a repeating unit represented by the following general formula (II), and is decomposed by the action of an acid to be soluble in an alkali developer. A photosensitive composition comprising an increasing polymer and (B) a compound capable of generating an acid upon irradiation with an actinic ray or radiation.

In general formulas (I) and (II):
L represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group.
Z represents an alkyl group, a cycloalkyl group or an aralkyl group.
L ′ is the same as L.
W is the same as Z.
Z and L and W and L ′ may be bonded to each other to form a 5- or 6-membered ring.
However, Z and W are not the same.
R ₁ represents a hydrogen atom or a substituent.
R ₂ is the same as R ₁ .
However, R ₁ and R ₂ are not all hydrogen atoms.
R ₃ , R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom or a substituent.
a, b, c and d are 1 ≦ a, 1 ≦ b, 1 ≦ c, 1 ≦ d, and 2 ≦ (a + b) ≦ 5 and 2 ≦ (c + d) ≦ 5, respectively.

  (2) The photosensitive composition according to (1), wherein W is a group having a cycloalkyl group or an aryl group, and Z is an alkyl group.

  (3) W is C8 or more, and Z is C8 or less, The photosensitive composition as described in (1) or (2) characterized by the above-mentioned.

(4) The photosensitive composition according to any one of (1) to (3), which is exposed to X-rays, electron beams or EUV.

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

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

  (6) W is a group which has an alicyclic group or an aromatic group, The photosensitive composition in any one of (1)-(4) characterized by the above-mentioned.

  (7) The photosensitive composition according to any one of (1) to (4) and (6), further comprising a silicon-based and / or fluorine-based surfactant.

  (8) The photosensitive composition as described in any one of (1) to (4), (6) and (7), further comprising a basic compound.

  (9) The photosensitive composition as described in any one of (1) to (4) and (6) to (8), further comprising a solvent.

  The present invention can provide a photosensitive composition having high sensitivity, high resolution, low line edge roughness, and suppressed pattern collapse, and a pattern forming method using the same.

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

(A) A polymer having a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II), which is decomposed by the action of an acid to increase the solubility in an alkali developer. The photosensitive composition has a repeating unit represented by the following general formula (I) and a repeating unit represented by the following general formula (II), and is decomposed by the action of an acid to be soluble in an alkaline developer. (Hereinafter also referred to as “acid-decomposable polymer (A)”).

In general formulas (I) and (II):
L represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group.
Z represents an alkyl group, a cycloalkyl group or an aralkyl group.
L ′ is the same as L.
W is the same as Z.
Z and L and W and L ′ may be bonded to each other to form a 5- or 6-membered ring.
However, Z and W are not the same.
R ₁ represents a hydrogen atom or a substituent.
R ₂ is the same as R ₁ .
However, R ₁ and R ₂ are not all hydrogen atoms.
R ₃ , R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom or a substituent.
a, b, c and d are 1 ≦ a, 1 ≦ b, 1 ≦ c, 1 ≦ d, and 2 ≦ (a + b) ≦ 5 and 2 ≦ (c + d) ≦ 5, respectively.

Examples of the alkyl group of L, L ′, Z and W in the general formulas (I) and (II) include, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t -C1-C20 linear or branched alkyl groups, such as a butyl group, a pentyl group, a hexyl group, an octyl group, a dodecyl group, are mentioned.
Examples of the cycloalkyl group of L, L ′, Z and W include cycloalkyl groups having 3 to 20 carbon atoms such as a cyclopentyl group and a cyclohexyl group.

  Preferable substituents that the alkyl group and cycloalkyl group of L, L ′, Z and W may have include, for example, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a halogen atom, a nitro group, and an acyl group. Groups, acyloxy groups, acylamino groups, sulfonylamino groups, alkyl or cycloalkylthio groups, arylthio groups, aralkylthio groups, thiophenecarbonyloxy groups, thiophenemethylcarbonyloxy groups, heterocyclic residues such as pyrrolidone residues, etc. Preferably, it has 12 or less carbon atoms.

Examples of the alkyl group having a substituent include, for example, cyclohexylethyl group, alkyl or cycloalkylcarbonyloxymethyl group, alkyl or cycloalkylcarbonyloxyethyl group, arylcarbonyloxyethyl group, aralkylcarbonyloxyethyl group, alkyl or cycloalkyloxymethyl. Group, aryloxymethyl group, aralkyloxymethyl group, alkyl or cycloalkyloxyethyl group, aryloxyethyl group, aralkyloxyethyl group, alkyl or cycloalkylthiomethyl group, arylthiomethyl group, aralkylthiomethyl group, alkyl or cyclo Examples thereof include an alkylthioethyl group, an arylthioethyl group, an aralkylthioethyl group, and the like.

  The alkyl group and cycloalkyl group in these groups are not particularly limited, but may further have a substituent such as an alkyl group or an alkoxy group.

  Examples of the alkyl or cycloalkylcarbonyloxyethyl group include a cyclohexylcarbonyloxyethyl group, a t-butylcyclohexylcarbonyloxyethyl group, an n-butylcyclohexylcarbonyloxyethyl group, and the like.

  Aryl is not particularly limited, but generally includes those having 6 to 14 carbon atoms such as phenyl group, xylyl group, toluyl group, cumenyl group, naphthyl group, anthracenyl group, and further, alkyl group, cycloalkyl group, alkoxy group. You may have substituents, such as group. Examples of the aryloxyethyl group include a phenyloxyethyl group, a cyclohexylphenyloxyethyl group, and the like.

  Aralkyl is not particularly limited, and examples thereof include a benzyl group. Examples of the aralkylcarbonyloxyethyl group include a benzylcarbonyloxyethyl group.

  In the general formulas (I) and (II), examples of the aralkyl group of L, L ′, Z and W include those having 7 to 15 carbon atoms such as benzyl group and phenethyl group.

  Preferred examples of the substituent for the aralkyl group include an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acylamino group, a sulfonylamino group, an alkyl or cycloalkylthio group, an arylthio group, and an aralkylthio group. Examples of the aralkyl group having a substituent include an alkoxybenzyl group, a hydroxybenzyl group, and a phenylthiophenethyl group. The range of the number of carbon atoms of the substituent that the aralkyl group as L, L ′, Z or W may have is preferably 12 or less.

  Examples of the 5- or 6-membered ring formed by combining Z and L and W and L ′ with each other include a tetrahydropyran ring and a tetrahydrofuran ring.

In the present invention, in the acid-decomposable polymer (A), Z and W are not the same.
The case where Z and W are not the same includes the case where Z and W are both an alkyl group, a cycloalkyl group, or an aralkyl group and have different carbon numbers.
Also, in order for Z and W not to be the same, one of Z and L and W and L ′ are bonded to each other to form a 5- or 6-membered ring, and the other forms a 5- or 6-membered ring. The case of not doing is included.
In the present invention, it is preferable that W is a group having a cycloalkyl group or an aryl group, and Z is an alkyl group, assuming that Z and W are not the same. Thereby, the effect of the present invention becomes more remarkable. Here, as a cycloalkyl group, C5-C12 things, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecanyl group, are preferable. As the aryl group, those having 6 to 16 carbon atoms such as a phenyl group and a naphthyl group are preferable, and these groups further have a substituent such as a methylphenyl group and an ethylphenyl group. It may be. These cycloalkyl groups or aryl groups may be formed as a group corresponding to W by themselves, but may be bonded directly to an alkyl group (preferably having 1 to 5 carbon atoms) or via another linking group. Good. Examples of the group having a cycloalkyl group or an aryl group of W include phenoxyethyl group, cyclohexylphenoxyethyl group, cyclohexylthioethyl group, t-butylcyclohexylcarbonyloxyethyl group, n-butylcyclohexylcarbonyloxyethyl group, cyclohexanone-4- An yl-phenoxyethyl group, a cyclohexyl group, a cyclohexylethyl group, a phenethyl group and a benzyl group are preferred, and a cyclohexylethyl group is particularly preferred. An alkyl group or an aralkyl group can be further improved in edge roughness by introducing a bulky group such as a phenyl group or a cyclohexyl group at the terminal. As the alkyl group for Z, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an i-butyl group, and a t-butyl group are preferable, and an ethyl group is particularly preferable.
W preferably has 8 or more carbon atoms, and Z preferably has 8 or less carbon atoms.

  L and L ′ are preferably a hydrogen atom or an alkyl group (preferably having 1 to 5 carbon atoms), and more preferably a hydrogen atom or a methyl group.

The substituent for R ₁ and R ₂ is not particularly limited, and examples thereof include halogen atoms, alkyl groups, cycloalkyl groups (including bicycloalkyl groups and tricycloalkyl groups), alkenyl groups (cyclo Alkenyl group, bicycloalkenyl group), alkynyl group, aryl group, heterocyclic group (including heterocyclic group), cyano group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group , Acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including anilino group), ammonio group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, Sulfamoylamino group Alkyl, arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl Group, alkylthiocarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boron Examples include an acid group (—B (OH) ₂ ), a phosphato group (—OPO (OH) ₂ ), a sulfato group (—OSO ₃ H), and other known substituents.

As the substituent for R ₁ and R ₂ , an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an acyl group, an acyloxy group, an alkoxycarbonyl group, an alkylthiocarbonyl group, A cyano group, a nitro group, and a carboxyl group are mentioned.
The alkyl group is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, A pentyl group, an isopentyl group, a neopentyl group, a t-pentyl group, and the like can be given.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms, for example, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecanoyl group, an adamantyl group, or a norbornyl group. And boronyl group.
The alkenyl group is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.
The aryl group is preferably an aryl group having 6 to 18 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, and an n-butoxy group.
The aryloxy group is preferably an aryloxy group having 6 to 20 carbon atoms, and examples thereof include a phenoxy group.
The alkylthio group is preferably an alkylthio group having 1 to 5 carbon atoms, and examples thereof include a methylthio group, an ethylthio group, a propylthio group, an isopropylthio group, an n-butylthio group, an isobutylthio group, and a sec-butylthio group.
The acyl group is preferably an acyl group having 1 to 8 carbon atoms, and examples thereof include formyl group, acetyl group, propionyl group, butyryl group, valeryl group, pivaloyl group, and benzoyl group.
The acyloxy group is preferably an acyloxy group having 2 to 8 carbon atoms, and examples thereof include an acetoxy group, a propionyloxy group, a butyroxy group, a valeryloxy group, a pivaloyloxy group, a hexanoyloxy group, an octanoyloxy group, and a benzoyloxy group. Can do.
The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2 to 6 carbon atoms, and examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group.
The alkylthiocarbonyl group is preferably an alkylthiocarbonyl group having 2 to 6 carbon atoms, such as a methylthiocarbonyl group, an ethylthiocarbonyl group, a propylthiocarbonyl group, an isopropylthiocarbonyl group, an n-butylthiocarbonyl group, an isobutylthiocarbonyl group, A sec-butylthiocarbonyl group etc. can be mentioned.

In the present invention, R ₁ and R ₂ are not all hydrogen atoms, which means that at least one of R ₁ and R ₂ is a substituent.

One or both of R ₁ and R ₂ preferably have a carbonyl group.

R ₁ and R ₂ are preferably in the ortho position of the acetal group.

The substituent for R ₃ and R ₄ is not particularly limited and includes, for example, halogen atoms, alkyl groups (including cycloalkyl groups, bicycloalkyl groups, and tricycloalkyl groups), alkenyl groups (cyclo Alkenyl group, bicycloalkenyl group), alkynyl group, aryl group, heterocyclic group (also referred to as heterocyclic group), cyano group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, hetero Ring oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including anilino group), ammonio group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonyl Amino group, sulfamoyl Amino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, Alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group Examples include (—B (OH) ₂ ), phosphato group (—OPO (OH) ₂ ), sulfato group (—OSO ₃ H), and other known substituents.

R ₃ and R ₄ are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

The substituent for R ₅ and R ₆ is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec- A butyl group etc. can be mentioned.
R ₅ and R ₆ are preferably a hydrogen atom or a methyl group.

  The acid-decomposable polymer (A) is represented by 5 to 60 mol% (preferably 5 to 30 mol%) of the repeating unit represented by the general formula (I) and the general formula (II) in all repeating units. It is preferable to have 20 to 80 mol% (preferably 40 to 80 mol%) of repeating units, and may have other repeating units as necessary. The content ratio ((I) :( II)) of the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II) in the acid-decomposable polymer (A) is preferably 0. .10: 1 to 1: 0.10, more preferably 0.25: 1 to 1: 0.25.

  The acid-decomposable polymer (A) preferably has a repeating unit represented by the following general formula (III).

In general formula (III):
R ₇ and R ₈ each independently represents a hydrogen atom or a substituent.
e and f are 1 ≦ e, 1 ≦ f, and 2 ≦ (e + f) ≦ 5, respectively.

In the general formula (III), R ₇ is the same as R ₁ in the general formula (I), and R ₈ is the same as R _{3 in} the general formula (I). It is.

  The acid-decomposable polymer (A) preferably has 20 to 80 mol% (preferably 40 to 80 mol%) of the repeating unit represented by the general formula (III) in all repeating units.

  The acid-decomposable polymer (A) of the present invention comprises, for example, a polymer having a phenolic hydroxyl group, preferably dissolved in an organic solvent, and after dehydrating water in the system by a technique such as azeotropic distillation, It can be obtained by adding an alkyl vinyl ether compound and an acid catalyst to perform an acetalization reaction and introducing a desired acetal group into a phenolic hydroxyl group.

The polymer having a phenolic hydroxyl group is preferably a polymer of hydroxystyrenes, and may be a copolymer with an acid-decomposable (meth) acrylate such as t-butyl acrylate or t-butyl methacrylate.
The polymer of hydroxystyrenes is preferably a polymer of hydroxystyrene having a substituent, or a copolymer of hydroxystyrene having a substituent and hydroxystyrene. Examples of the substituent include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an acyl group, an acyloxy group, an alkoxycarbonyl group, an alkylthiocarbonyl group, a cyano group, a nitro group, A carboxyl group is mentioned.

  In order to adjust the alkali solubility of the acid-decomposable polymer (A), a non-acid-decomposable group can be introduced into the polymer having a phenolic hydroxyl group. Non-acid-decomposable groups can be introduced by copolymerizing styrenes, non-acid-decomposable (meth) acrylic esters, non-acid-decomposable (meth) acrylic amides, hydroxystyrenes, A method of protecting the hydroxyl group with a non-acid-decomposable substituent is preferred.

  As a substituent of the non-acid-decomposable group, an acetyl group, a mesyl group, a toluenesulfonyl group and the like are preferable, but not limited thereto.

  Examples of the styrenes include styrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, iodostyrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, methoxystyrene, ethoxystyrene, phenylstyrene, t-butylstyrene, t -Butoxystyrene and the like can be mentioned, and styrene, methylstyrene, t-butylstyrene, and t-butoxystyrene are particularly preferable.

  Examples of the non-acid-decomposable (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, and glycidyl (meth) acrylate. , Benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, and the like.

  Non-acid-decomposable (meth) acrylic acid amides include (meth) acrylic acid amide, (meth) acrylic acid phenylamide, (meth) acrylic acid isopropylamide and the like.

  Furthermore, examples of the copolymerizable monomer include maleic acid derivatives, maleic anhydride derivatives, (meth) acrylonitrile, vinyl pyrrolidone, vinyl pyridine, and vinyl acetate.

  As described above, a copolymer component and / or a non-acid-decomposable group is added to the polymer having a phenolic hydroxyl group as long as the alkali solubility of the acid-decomposable polymer (A) is adjusted and the alkali developability is not impaired. Although it is possible to introduce, in general, among the components constituting the polymer having a phenolic hydroxyl group, the hydroxystyrene component occupies 60 mol% or more, preferably 70 mol% or more of dry etching resistance and sensitivity. Desirable in terms.

  The weight average molecular weight of the above-mentioned trunk polymer (polymer having a phenolic hydroxyl group) can be measured as a polystyrene-equivalent molecular weight (Mw) by gel permeation chromatography (GPC), preferably 500 to 200,000. 500 to 30,000 is more preferable, and 500 to 4,000 is particularly preferable. By setting the molecular weight to 200,000 or less, it is possible to prevent the tendency that the solubility is inferior and the resolution decreases, and by setting the molecular weight to 500 or more, it is possible to prevent the tendency of the pattern collapse performance to deteriorate. .

As the alkyl vinyl ether compound used in the acetalization reaction, the following general formula (A)
Is desirable.
R ¹ —O—CH═CH ₂ General Formula (A)
In the formula, R ¹ represents an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl which may have a substituent. Represents a group.

The alkyl group which may have a substituent for R ¹ is preferably 1 to 20 carbon atoms, more preferably 1 to 18 carbon atoms, which may be linear or branched, For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, i-pentyl group, t-pentyl group, n- Hexyl group, i-hexyl group, t-hexyl group, n-heptyl group, i-heptyl group, t-heptyl group, n-octyl group, i-octyl group, t-octyl group, n-nonyl group, i- Nonyl group, t-nonyl group, n-decyl group, i-decyl group, t-decyl group, n-undecyl group, i-undecyl group, n-dodecyl group, i-dodecyl group, n-tridecyl group, i- Tridecyl group, n-tetradecyl group, i-tetradecyl group , N-pentadecyl group, i-pentadecyl group, n-hexadecyl group, i-hexadecyl group, n-heptadecyl group, i-heptadecyl group, n-octadecyl group, i-octadecyl group, n-nonadecyl group, i-nonadecyl group Etc. These alkyl groups may be substituted by the substituent shown below.

The cycloalkyl group which may have a substituent for R ¹ is preferably a cycloalkyl group having 3 to 20 carbon atoms, more preferably a cycloalkyl group having 3 to 18 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, Cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, cyclotridecyl, cyclotridecyl, cyclotetradecyl, cyclopentadecyl, cyclohexyl Sadecyl group, cycloheptadecyl group, cyclooctadecyl group, cyclononadecyl group, 4-cyclohexylcyclohexyl group, 4-n-hexylcyclohexyl group, pentanylcyclohexyl group, hexyloxycyclohexyl group, pentanyloxycyclohexyl group, etc. It is possible. These cycloalkyl groups may be substituted with the substituents shown below.

The aryl group which may have a substituent for R ¹ is preferably an aryl group having 6 to 30 carbon atoms, preferably 6 to 25 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, Ethylphenyl group, propylphenyl group, methoxyphenyl group, ethoxyphenyl group, propyloxyphenyl group, 4-cyclopentylphenyl group, 4-cyclohexylphenyl group, 4-cycloheptenylphenyl group, 4-cyclooctanylphenyl group, 2 -Cyclopentylphenyl group, 2-cyclohexylphenyl group, 2-cycloheptenylphenyl group, 2-cyclooctanylphenyl group, 3-cyclopentylphenyl group, 3-cyclohexylphenyl group, 3-cycloheptenylphenyl group, 3-cyclo Octanylphenyl group, 4-cyclopentyloxy Enyl group, 4-cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentylphenyl group, 4-n-hexylphenyl group, 4-n-heptenylphenyl group, 4-n-octanylphenyl group, 2-n-pentylphenyl group, 2-n-hexylphenyl group, 2-n-heptenylphenyl group , 2-n-octanylphenyl group, 3-n-pentyl Phenyl group, 3-n-hexylphenyl group, 3-n-heptenylphenyl group, 3-n-octanylphenyl group, 2,6-di-isopropylphenyl group, 2,3-di-isopropylphenyl group, 2 , 4-di-isopropylphenyl group, 3,4-di-isopropylphenyl group, 3,6-di-t-butylphenyl group, 2,3-di-t-butylphenyl group, 2,4-di-t -Butylphenyl group, 3,4-di-t-butylphenyl group, 2,6-di-n-butylphenyl group, 2,3-di-n-butylphenyl group, 2,4-di-n-butyl Phenyl group, 3,4-di-n-butylphenyl group, 2,6-di-i-butylphenyl group, 2,3-di-i-butylphenyl group, 2,4-di-i-butylphenyl group 3,4-di-i-butylphenyl group, 2,6-di-t Amylphenyl group, 2,3-di-t-amylphenyl group, 2,4-di-t-amylphenyl group, 3,4-di-t-amylphenyl group, 2,6-di-i-amylphenyl Group, 2,3-di-i-amylphenyl group, 2,4-di-i-amylphenyl group, 3,4-di-i-amylphenyl group, 2,6-di-n-pentylphenyl group, 2,3-di-n-pentylphenyl group, 2,4-di-n-pentylphenyl group, 3,4-di-n-pentylphenyl group, 4-adamantylphenyl group, 2-adamantylphenyl group, 4- Isobornylphenyl group, 3-isobornylphenyl group, 2-isobornylphenyl group, 4-cyclopentyloxyphenyl group, 4-cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooct Nyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentyloxyphenyl group, 4-n-hexyloxyphenyl group, 4-n-heptenyloxyphenyl group, 4-n -Octanyloxyphenyl group, 2-n-pentyloxyphenyl group, 2-n-hexyloxyphenyl group, 2-n-heptenyloxyphenyl group, 2-n-octanyloxyphenyl group, 3-n-pentyl An oxyphenyl group, a 3-n-hexyloxyphenyl group, 3-n-heptenyloxyphenyl group, 3-n-octanyloxyphenyl group, 2,6-di-isopropyloxyphenyl group, 2,3-di-isopropyloxyphenyl group, 2,4-di-isopropyloxy Phenyl group, 3,4-di-isopropyloxyphenyl group, 2,6-di-t-butyloxyphenyl group, 2,3-di-t-butyloxyphenyl group, 2,4-di-t-butyloxy Phenyl group, 3,4-di-t-butyloxyphenyl group, 2,6-di-n-butyloxyphenyl group, 2,3-di-n-butyloxyphenyl group, 2,4-di-n- Butyloxyphenyl group, 3,4-di-n-butyloxyphenyl group, 2,6-di-i-butyloxyphenyl group, 2,3-di-i-butyloxyphenyl group, 2,4-di- i-Butyloxy Phenyl group, 3,4-di-i-butyloxyphenyl group, 2,6-di-t-amyloxyphenyl group, 2,3-di-t-amyloxyphenyl group, 2,4-di-t- Amyloxyphenyl group, 3,4-di-t-amyloxyphenyl group, 2,6-di-i-amyloxyphenyl group, 2,3-di-i-amyloxyphenyl group, 2,4-di- i-amyloxyphenyl group, 3,4-di-i-amyloxyphenyl group, 2,6-di-n-pentyloxyphenyl group, 2,3-di-n-pentyloxyphenyl group, 2,4- Di-n-pentyloxyphenyl group, 3,4-di-n-pentyloxyphenyl group, 4-adamantyloxyphenyl group, 3-adamantyloxyphenyl group, 2-adamantyloxyphenyl group, 4-isoboronyloxy Eniru group, 3-isobornyl oxyphenyl group, 2-isobornyl oxyphenyl group, and the like. These aryl groups may be substituted by the substituent shown below.

The aralkyl group which may have a substituent of R ¹ is preferably an aralkyl group having 7 to 30 carbon atoms, more preferably 8 to 25 carbon atoms, such as a phenylethyl group, a tolylphenylethyl group, a cycloalkyl group. Silylphenylethyl group, ethylphenylethyl group, propylphenylethyl group, 4-cyclopentylphenylethyl group, 4-cyclohexylphenylethyl group, 4-cycloheptenylphenylethyl group, 4-cyclooctanylphenylethyl group, 2-cyclopentyl Phenylethyl group, 2-cyclohexylphenylethyl group, 2-cycloheptenylphenylethyl group, 2-cyclooctanylphenylethyl group, 3-cyclopentylphenylethyl group, 3-cyclohexylphenylethyl group, 3-cycloheptenylphenylethyl Group, 3-sik Octanylphenylethyl group, 4-cyclopentyloxyphenylethyl group, 4-cyclohexyloxyphenylethyl group, 4-cycloheptenyloxyphenylethyl group, 4-cyclooctanyloxyphenylethyl group, 2-cyclopentyloxyphenylethyl group, 2-cyclohexyloxyphenylethyl group, 2-cycloheptenyloxyphenylethyl group, 2-cyclooctanyloxyphenylethyl group, 3-cyclopentyloxyphenylethyl group, 3-cyclohexyloxyphenylethyl group, 3-cycloheptenyloxy Phenylethyl group, 3-cyclooctanyloxyphenylethyl group, 4-n-pentylphenylethyl group, 4-n-hexylphenylethyl group, 4-n-heptenylphenylethyl group, 4-n-octanyl Phenylethyl group, 2-n-pentylphenylethyl group, 2-n-hexylphenylethyl group, 2-n-heptenylphenylethyl group, 2-n-octanylphenylethyl group, 3-n-pentylphenylethyl group 3-n-hexylphenylethyl group, 3-n-heptenylphenylethyl group, 3-n-octanylphenylethyl group, 2,6-diisopropylphenylethyl group, 2,3-diisopropylphenylethyl group Group, 2,4-di-isopropylphenylethyl group, 3,4-di-isopropylphenylethyl group, 2,6-di-t-butylphenylethyl group, 2,3-di-t-butylphenylethyl group, 2,4-di-t-butylphenylethyl group, 3,4-di-t-butylphenylethyl group, 2,6-di-n-butylphenylethyl group, , 3-Di-n-butylphenylethyl group, 2,4-di-n-butylphenylethyl group, 3,4-di-n-butylphenylethyl group, 2,6-di-i-butylphenylethyl group 2,3-di-i-butylphenylethyl group, 2,4-di-i-butylphenylethyl group, 3,4-di-i-butylphenylethyl group, 2,6-di-t-amylphenyl Ethyl group, 2,3-di-t-amylphenylethyl group, 2,4-di-t-amylphenylethyl group, 3,4-di-t-amylphenylethyl group, 2,6-di-i- Amylphenylethyl group, 2,3-di-i-amylphenylethyl group, 2,4-di-i-amylphenylethyl group, 3,4-di-i-amylphenylethyl group, 2,6-di- n-pentylphenylethyl group, 2,3-di-n-pentyl Enylethyl group, 2,4-di-n-pentylphenylethyl group, 3,4-di-n-pentylphenylethyl group, 4-adamantylphenylethyl group, 3-adamantylphenylethyl group, 2-adamantylphenylethyl group, 4-isobornylphenylethyl group, 3-isobornylphenylethyl group, 2-isobornylphenylethyl group, 4-cyclopentyloxyphenylethyl group, 4-cyclohexyloxyphenylethyl group, 4-cycloheptenyloxyphenyl Ethyl group, 4-cyclooctanyloxyphenylethyl group, 2-cyclopentyloxyphenylethyl group, 2-cyclohexyloxyphenylethyl group, 2-cycloheptenyloxyphenylethyl group, 2-cyclooctanyloxyphenylethyl group, 3 -Cyclopentyl Oxyphenylethyl group, 3-cyclohexyloxyphenylethyl group, 3-cycloheptenyloxyphenylethyl group, 3-cyclooctanyloxyphenylethyl group, 4-n-pentyloxyphenylethyl group, 4-n-hexyloxy Phenylethyl group, 4-n-heptenyloxyphenylethyl group, 4-n-octanyloxyphenylethyl group, 2-n-pentyloxyphenylethyl group, 2-n-hexyloxyphenylethyl group, 2-n- Heptenyloxyphenylethyl group, 2-n-octanyloxyphenylethyl group, 3-n-pentyloxyphenylethyl group, 3-n-hexyloxyphenylethyl group, 3-n-heptenyloxyphenylethyl group, 3 -N-octanyloxyphenylethyl group, 2,6-diisopro Ruoxyphenylethyl group, 2,3-di-isopropyloxyphenylethyl group, 2,4-di-isopropyloxyphenylethyl group, 3,4-diisopropyloxyphenylethyl group, 2,6-di-t-butyl Oxyphenylethyl group, 2,3-di-t-butyloxyphenylethyl group, 2,4-di-t-butyloxyphenylethyl group, 3,4-di-t-butyloxyphenylethyl group, 2,6 -Di-n-butyloxyphenylethyl group, 2,3-di-n-butyloxyphenylethyl group, 2,4-di-n-butyloxyphenylethyl group, 3,4-di-n-butyloxyphenyl group Ethyl group, 2,6-di-i-butyloxyphenylethyl group, 2,3-di-i-butyloxyphenylethyl group, 2,4-di-i-butyloxyphenyl Ethyl group, 3,4-di-i-butyloxyphenylethyl group, 2,6-di-t-amyloxyphenylethyl group, 2,3-di-t-amyloxyphenylethyl group, 2,4-di -T-amyloxyphenylethyl group, 3,4-di-t-amyloxyphenylethyl group, 2,6-di-i-amyloxyphenylethyl group, 2,3-di-i-amyloxyphenylethyl group 2,4-di-i-amyloxyphenylethyl group, 3,4-di-i-amyloxyphenylethyl group, 2,6-di-n-pentyloxyphenylethyl group, 2,3-di-n -Pentyloxyphenylethyl group, 2,4-di-n-pentyloxyphenylethyl group, 3,4-di-n-pentyloxyphenylethyl group, 4-adamantyloxyphenylethyl group, 3-adama Ntyloxyphenylethyl group, 2-adamantyloxyphenylethyl group, 4-isoboronyloxyphenylethyl group, 3-isoboronyloxyphenylethyl group, 2-isoboronyloxyphenylethyl group, or the above alkyl Examples thereof include those substituted with methyl group, propyl group, butyl group and the like. These aralkyl groups may be substituted by the substituents shown below.

  Further substituents for the above groups include hydroxyl groups, halogen atoms (fluorine, chlorine, bromine, iodine), nitro groups, cyano groups, the above alkyl groups, methoxy groups, ethoxy groups, hydroxyethoxy groups, propoxy groups, hydroxy groups. Propoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, alkoxy group such as t-butoxy group, alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, aralkyl group such as benzyl group, phenethyl group, cumyl group , Aralkyloxy group, formyl group, acetyl group, butyryl group, benzoyl group, cyanyl group, acyl group such as valeryl group, acyloxy group such as butyryloxy group, alkenyl group, vinyloxy group, propenyloxy group, allyloxy group, butenyloxy Alkenyloxy groups such as groups above It can be mentioned aryl group, an aryloxy group such as phenoxy group, aryloxycarbonyl group such as benzoyloxy group.

  These substituents may further have a substituent.

  Specific examples of the compound represented by the general formula (A) include, for example, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, n-hexyl vinyl ether, benzyl vinyl ether, Examples include cyclohexyl ethyl vinyl ether, phenoxy ethyl vinyl ether, cyclohexyl phenoxy ethyl vinyl ether, 4-carbonyl cyclohexyl phenoxy ethyl vinyl ether, t-butyl cyclohexyl carbonyloxy ethyl vinyl ether, cyclohexyl thioethyl vinyl ether, n-butyl cyclohexyl carbonyloxy ethyl vinyl ether, etc. Between the phenolic hydroxyl groups in the polymer As long as it causes the acetal reaction, but it is not limited to those described above. Among the above, ethyl vinyl ether, cyclohexyl ethyl vinyl ether, t-butyl vinyl ether, isopropyl vinyl ether, and cyclohexyl vinyl ether are preferable, and ethyl vinyl ether, cyclohexyl ethyl vinyl ether, and t-butyl vinyl ether are more preferable.

  The amount of the two or more alkyl vinyl ether compounds used in the reaction is preferably 5 mol% to 95 mol%, more preferably 10 mol, based on the phenolic hydroxyl group in the polymer having a phenolic hydroxyl group. % To 60 mol%, more preferably 15 mol% to 50 mol%.

  The organic solvent used in the reaction is not particularly limited as long as it is an inert solvent, and examples thereof include propylene glycol methyl ether acetate (PGMEA), 2-heptanone, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, and tetrahydrofuran. be able to. Of these, PGMEA and 2-heptanone are preferable.

  The reaction solvent is usually used in an amount of 100 to 1000 parts by weight with respect to 100 parts by weight of the polymer having a phenolic hydroxyl group.

  The acid-decomposable polymer (A) can be used alone or in combination of two or more. Also, a combination of acid decomposable polymers (A) synthesized from polymers having two or more phenolic hydroxyl groups having different molecular weights and composition ratios of polymers having phenolic hydroxyl groups, and two or more acid decompositions having different acetal protection rates Combinations of the functional polymers can also be selected to exhibit sensitivity, resolution, profile, and other resist characteristics.

  The acid-decomposable polymer (A) is synthesized by dissolving a polymer having a phenolic hydroxyl group in the organic solvent (a solvent inert to the acetalization reaction) shown above, and performing vacuum distillation or the like as necessary. Water is removed, and two or more alkyl vinyl ether compounds are added. Two or more alkyl vinyl ether compounds may be added simultaneously or sequentially. The acetalization reaction proceeds by adding an acidic catalyst.

  As the acid catalyst, either an inorganic acid or an organic acid can be used. The organic acid is preferable because it has no residual metal impurities, and p-toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt, and the like are more preferable.

  For the purpose of stopping the acetalization reaction, neutralization with a base compound is preferably performed. If this neutralization is not performed, there is a possibility that an acid remains and impairs the storage stability of the resist. The basic compound to be used is not particularly limited as long as the acid as the added catalyst is neutralized and the salt is removed in the water washing step. Among these, organic base compounds are preferable because they have no residual metal impurities, and specific examples include triethylamine, trimethylamine, pyridine, aminopyridine, piperazine, imidazole, and the like, and triethylamine and pyridine are particularly preferable.

  After the acetalization reaction is completed and neutralized, it is preferable to remove the salt remaining in the system using ultrapure water or the like.

  The weight average molecular weight of the acid-decomposable polymer (A) is preferably 500 to 4,000.

  Specific examples of the acid-decomposable polymer (A) include the following, but the present invention is not limited thereto.

  The content of the acid-decomposable polymer (A) in the composition is usually 70 to 98% by weight, preferably 75 to 96% by weight, more preferably based on the weight of the total solid content of the composition. Is 80 to 96% by weight.

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

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

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

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

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

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 5 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group ( Preferable examples include 2 to 7 carbon atoms, an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably 2 to 7 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 the substituent of these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, and an alkylthio group, and an alkyl group substituted with a fluorine atom is preferable.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
Z ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of Z ^{− in} formula (ZI).

General formulas (ZII) and (ZIII) in a phenyl group, 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.

  Examples of the compound that generates an acid upon irradiation with actinic rays or radiation that can be used 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.

  The compound that generates an acid upon irradiation with actinic rays or radiation is more preferably a compound represented by the following general formula (PI).

In general formula (PI),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent.
Za is a single bond or a divalent linking group.
X ⁻ represents a counter anion.

At least one of R ^{1 to} R ¹³ is preferably a substituent containing an alcoholic hydroxyl group.
An alcoholic hydroxyl group represents a hydroxyl group bonded to a carbon atom of an alkyl group.

When R ^{1 to} R ¹³ are substituents containing an alcoholic hydroxyl group, R ^{1 to} R ¹³ are represented by —W—Y. Y is an alkyl group substituted with a hydroxyl group, and W is a single bond or a divalent linking group.

As the alkyl group of Y, 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 Preferably ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group and sec-butyl group, more preferably ethyl group, propyl group and isopropyl group. Y particularly preferably contains a —CH ₂ CH ₂ OH structure.

  The divalent linking group represented by W is not particularly limited, and examples thereof include an alkoxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acylamino group, an aminocarbonylamino group, Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, alkylthio group, arylthio group, sulfamoyl group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxy Examples thereof include a divalent group in which an arbitrary hydrogen atom in a monovalent group such as a carbonyl group, an alkoxycarbonyl group, or a carbamoyl group is replaced with a single bond.

  W is preferably a single bond, an alkoxy group, an acyloxy group, an acylamino group, an alkyl and arylsulfonylamino group, an alkylthio group, an alkylsulfonyl group, an acyl group, an alkoxycarbonyl group, and any hydrogen atom in the carbamoyl group replaced with a single bond. It is a divalent group, more preferably a divalent group in which any hydrogen atom in a single bond, acyloxy group, alkylsulfonyl group, acyl group or alkoxycarbonyl group is replaced with a single bond.

When R ^{1 to} R ¹³ are substituents containing an alcoholic hydroxyl group, the number of carbon atoms contained is preferably 2 to 10, more preferably 2 to 6, and particularly preferably 2 to 4. .
The substituent containing an alcoholic hydroxyl group as R ^{1 to} R ¹³ may have two or more alcoholic hydroxyl groups. The number of alcoholic hydroxyl groups having a substituent containing an alcoholic hydroxyl group as R ^{1 to} R ¹³ is 1 to 6, preferably 1 to 3, and more preferably 1. preferable.
The number of alcoholic hydroxyl groups possessed by the compound represented by formula (PI) is preferably 1 to 10, more preferably 1 to 6, more preferably ^{1 to} R ^{13 in} total. The number is preferably 1 to 3.

When R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are each independently a hydrogen atom or a substituent, and any substituent may be used without any particular limitation. Atoms, alkyl groups (including cycloalkyl groups, bicycloalkyl groups, and tricycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, and heterocyclic groups (referred to as heterocyclic groups) Cyano group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group ( Anilino group), ammonio group, acylamino group, aminocarbonyl group Group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and aryl Sulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino Group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (—B (OH) ₂ ), phosphato group (—OPO (OH) ₂ ), sulfato group (—OSO ₃ H), and other known ones Substituents are mentioned as examples.

In addition, two adjacent R ^{1 to} R ¹³ may be combined to form a ring (aromatic or non-aromatic hydrocarbon ring or heterocyclic ring. These may be further combined to form a polycyclic fused ring. For example, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine Ring, pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, Phenanthridine ring, acridine ring, Ntororin ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, a phenothiazine ring and a phenazine ring.) May also be formed.

When R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are preferably a hydrogen atom or a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group ( (Including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, cyano groups, carboxyl groups, alkoxy groups, aryloxy groups, acyloxy groups, carbamoyloxy groups, acylamino groups, aminocarbonylamino groups, alkoxycarbonylamino groups , Aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, alkylthio group, arylthio group, sulfamoyl group, alkyl and arylsulfonyl group, aryloxycarbonyl group, alkoxycarbonyl , A carbamoyl group, an imido group, a silyl group, a ureido group.

When R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are more preferably a hydrogen atom or a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), a cyano group. , Alkoxy group, acyloxy group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, alkyl and arylsulfonylamino group, alkylthio group, sulfamoyl group, alkyl and arylsulfonyl group, alkoxycarbonyl group and carbamoyl group.
Further, when R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are particularly preferably a hydrogen atom or an alkyl group (including a cycloalkyl group, a bicycloalkyl group and a tricycloalkyl group), a halogen atom, An alkoxy group;

In general formula (PI), preferably at least one of R ^{1 to} R ¹³ contains an alcoholic hydroxyl group, more preferably at least one of R ^{9 to} R ¹³ contains an alcoholic hydroxyl group.

Za represents a single bond or a divalent linking group. Examples of the divalent linking group include an alkylene group, an arylene group, a carbonyl group, a sulfonyl group, a carbonyloxy group, a carbonylamino group, a sulfonylamide group, an ether group, and a thioether. Group, amino group, disulfide group, acyl group, alkylsulfonyl group, —CH═CH—, —C≡C—, aminocarbonylamino group, aminosulfonylamino group, etc., which may have a substituent. These substituents are the same as the substituents shown for R ^{1 to} R ¹³ above. Z preferably has a single bond, alkylene group, arylene group, ether group, thioether group, amino group, —CH═CH—, —C≡C—, aminocarbonylamino group, aminosulfonylamino group, etc. A substituent, more preferably a single bond, an ether group or a thioether group, particularly preferably a single bond.

The compound represented by the general formula (PI) has a counter anion X ⁻ . As an anion, an organic anion is desirable. An organic anion represents an anion containing at least one carbon atom. Furthermore, the organic anion is preferably a non-nucleophilic 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.
Examples of the non-nucleophilic anion include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.
Examples of the non-nucleophilic sulfonate anion include an alkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion. Examples of the non-nucleophilic carboxylate anion include an alkylcarboxylate anion, an arylcarboxylate anion, and an aralkylcarboxylate anion.

The alkyl moiety in the alkyl sulfonate anion may be an alkyl group or a cycloalkyl group, and preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, such as a methyl group or an ethyl group. 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 aryl group in the aryl 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.
Examples of the substituent of the alkyl group, cycloalkyl group and aryl group in the alkyl sulfonate anion and aryl 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 1 to 5 carbon atoms), cycloalkyl group (preferably 3 to 15 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), alkoxycarbonyl group (preferably May include 2 to 7 carbon atoms, an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably 2 to 7 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 alkyl moiety in the alkylcarboxylate anion include the same alkyl group and cycloalkyl group as in the alkylsulfonate anion. Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate 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.

Examples of the alkyl group, cycloalkyl group, aryl group and aralkyl group substituent in the alkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom, alkyl group as in the arylsulfonate anion, A cycloalkyl group, an alkoxy group, an alkylthio group, etc. can be mentioned. 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 the substituent for these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, and an alkylthio group.
Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

The counter anion X ⁻ of the compound represented by the general formula (PI) is preferably a sulfonate anion, more preferably an aryl sulfonic acid.
Specific examples of counter anions include methane sulfonate anion, trifluoromethane sulfonate anion, pentafluoroethane sulfonate anion, heptafluoropropane sulfonate anion, perfluorobutane sulfonate anion, perfluorohexane sulfonate anion, perfluoro. Octane sulfonate anion, pentafluorobenzene sulfonate anion, 3,5-bistrifluoromethylbenzene sulfonate anion, 2,4,6-triisopropylbenzene sulfonate anion, perfluoroethoxyethane sulfonate anion, 2, 3, 5 , 6-tetrafluoro-4-dodecyloxybenzenesulfonate anion, p-toluenesulfonate anion, 2,4,6-trimethylbenzenesulfonate anion, and the like.

  The compound represented by the general formula (PI) is a method in which a benzene derivative containing a hydroxyl group protected by a protecting group as a substituent and a cyclic sulfoxide compound are condensed to form a sulfonium salt, and the protecting group of the hydroxyl group is deprotected. Can be synthesized.

(In the figure, W is a divalent linking group, R is an alkylene group, and P is a protecting group.)

Examples of acids used for the reaction of sulfoniumation include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, p-ethylbenzenesulfonic acid, Nonafluorobutanesulfonic acid and the like can be mentioned, and the conjugate base of the acid used becomes the anion of sulfonium. Examples of the condensing agent used in the sulfoniumation reaction include acid anhydrides, such as trifluoroacetic acid anhydride, polyphosphoric acid, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, p-toluenesulfonic acid anhydride, nona. Examples include strong acid anhydrides such as fluorobutanesulfonic anhydride, tetrafluorosuccinic anhydride, hexafluoroglutaric anhydride, chlorodifluoroacetic anhydride, pentafluoropropionic anhydride, heptafluorobutanoic anhydride.
Examples of the hydroxyl-protecting group P include ethers and esters, and examples include methyl ether, aryl ether, benzyl ether, acetic acid ester, benzoic acid ester, and carbonic acid ester.
The counter anion X ⁻ can be converted into a desired anion by passing through an ion exchange resin and adding a conjugate acid of the target anion.

Of the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are more preferable.
Further, as a compound that generates an acid by radiation of actinic rays or radiation, a compound that generates an acid having one sulfonic acid group or imide group is preferable, and a compound that generates monovalent perfluoroalkanesulfonic acid, more preferably, Or a compound generating an aromatic sulfonic acid substituted with a monovalent fluorine atom or a group containing a fluorine atom, or a compound generating an imido acid substituted with a monovalent fluorine atom or a group containing a fluorine atom is there. 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 the compounds that generate an acid upon irradiation with actinic rays or radiation, 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.

Basic Compound The photosensitive composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating.

  Preferable structures include structures represented by the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, And R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

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

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

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

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

  When the photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development defects can be obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A small resist pattern can be provided.

  Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.

Examples of commercially available surfactants that can be used include EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, and R08. (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of fluorine and / or silicon surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the photosensitive composition (excluding the solvent). is there.

Antioxidant The photosensitive composition of the present invention preferably contains an antioxidant.
The antioxidant is for preventing the organic material from being oxidized in the presence of oxygen.

  The antioxidant is not particularly limited as long as it is effective in preventing the oxidation of commonly used plastics, for example, a phenolic antioxidant, an antioxidant made of an organic acid derivative, and a sulfur-containing agent. Antioxidants, phosphorus antioxidants, amine antioxidants, antioxidants composed of amine-aldehyde condensates, antioxidants composed of amine-ketone condensates, and the like. Of these antioxidants, phenol antioxidants and antioxidants composed of organic acid derivatives are used as antioxidants in order to exhibit the effects of the present invention without reducing the function of the resist. Is preferred.

Here, as the phenolic antioxidant, substituted phenols such as 1-oxy-3-methyl-4-isopropylbenzene, 2,6-di-tert-butylphenol, 2,6-di-tert- Butyl-4-ethylphenol, 2,6-di-
Tert-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-tert-butylphenol, butylhydroxyanisole, 2- (1-methylcyclohexyl) -4,6-dimethylphenol, 2,4 -Dimethyl-6-tert-butylphenol, 2-methyl-4,6-dinonylphenol, 2,6
-Di-tert-butyl-α-dimethylamino-p-cresol, 6- (4-
Hydroxy-3,5-di-tert-butylanilino) 2,4-bisoctyl-thio-1,3,5-triazine, n-octadecyl-3- (4'-hydroxy-3 ', 5' -Di-tert-butyl-phenyl) propionate, octylated phenol, aralkyl-substituted phenols, alkylated-p-cresol, hindered phenol, etc., bis, tris, polyphenols such as 4, 4'- Dihydroxy diphenyl, methylene bis (dimethyl-4,6-phenol), 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis- (4 -Methyl-6-cyclohexyl-phenol), 2,2'-methylene-bis- (4- Ethyl-6-tert-butylphenol), 4,4'-methylene-bis- (2,6-di-tert-butylphenol), 2,2'-methylene-bis- (6-alphamethyl-benzyl-p -Cresol), methylene-bridged polyhydric alkylphenols, 4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2, 2 '-Dihydroxy-3,3'-di- (α-methylcyclohexyl) -5,5'-dimethyldiphenylmethane, alkylated bisphenol, hindered bisphenol, 1,3,5-trimethyl-2,4,6-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl) ben Tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tetrakis- [methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) Propionate] Examples include methane.

  Preferable specific examples of the antioxidant used in the present invention include 2,6-di-t-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-t-butylphenol, and 2,2′-methylenebis. (4-methyl-6-t-butylphenol), butylhydroxyanisole, t-butylhydroquinone, 2,4,5-trihydroxybutyrophenone, nordihydroguaiaretic acid, propyl gallate, octyl gallate, lauryl gallate, And isopropyl citrate. Of these, 2,6-di-t-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-t-butylphenol, butylhydroxyanisole, and t-butylhydroquinone are preferred, and 2,6-di- -T-Butyl-4-methylphenol or 4-hydroxymethyl-2,6-di-t-butylphenol is more preferred.

The content of the antioxidant is preferably 1 ppm or more in the photosensitive composition.
More preferably, it is at least p pm, even more preferably at least 10 pp pm, even more preferably at least 50 pp pm, and 10 0 pp pm
It is still more preferable that it is above, and it is especially preferable that it is 1 0 0-1 0 0 0 0 pp m. A plurality of antioxidants may be mixed and used.

Organic Solvent The photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent.

  Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

(Ia) Ketone solvent The solvent used in the present invention is preferably a solvent having at least one ketone structure.
Examples of the solvent having a ketone structure include a chain ketone solvent and a cyclic ketone solvent, and a compound having a total carbon number of 5 to 8 is preferable because of good coatability.
Examples of chain ketone solvents include 2-heptanone, methyl ethyl ketone, and methyl isobutyl ketone, with 2-heptanone being preferred.
Examples of the cyclic ketone solvent include cyclopentanone, 3-methyl-2-cyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, cycloheptanone, cyclooctanone, and isophorone. Are cyclohexanone and cycloheptanone.

The solvent is preferably used as a solvent having a ketone structure alone or as a mixed solvent with other solvents. Examples of the solvent to be mixed (combined solvent) include propylene glycol monoalkyl ether carboxylate, alkyl lactate, propylene glycol monoalkyl ether, alkyl alkoxypropionate, and lactone compound.
Examples of the propylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate and the like.
Examples of the alkyl lactate include methyl lactate and ethyl lactate.
Examples of the propylene glycol monoalkyl ether include propylene glycol monomethyl ether and propylene glycol monoethyl ether.
Examples of the alkyl alkoxypropionate include methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, and ethyl ethoxypropionate.
Examples of the lactone compound include γ-butyrolactone.

  Preferred examples of the combined solvent include propylene glycol monoalkyl ether carboxylate, alkyl lactate, and propylene glycol monoalkyl ether. More preferable examples of the combined solvent include propylene glycol monomethyl ether acetate.

By mixing the ketone solvent and the combined solvent, substrate adhesion, developability, DOF, and the like are improved.
The ratio (mass ratio) of the ketone solvent and the combined solvent is preferably 10/90 to 95/5, more preferably 20/80 to 80/20, still more preferably 30/70 to 70/30.

Moreover, you may mix the high boiling point solvent of 200 degreeC or more of boiling points, such as ethylene carbonate and a propylene carbonate, from a viewpoint of improving film thickness uniformity and development defect performance.
The addition amount of these high-boiling solvents is usually 0.1 to 15% by mass, preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass in the total solvent.

  In the present invention, the solvent is used alone, preferably two or more kinds of solvents, and the solid content concentration is usually 1 to 20% by mass, preferably 1 to 10% by mass, more preferably 1 to 10% by mass. An 8% by weight photosensitive composition is prepared.

  If necessary, the photosensitive composition of the present invention further promotes solubility in surfactants other than dyes, plasticizers, fluorine-based and / or silicon-based surfactants, photosensitizers, and developers. A compound etc. can be contained.

  The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.

  The preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, more preferably 5 to 30% by mass with respect to the resin of component (C) or the resin of component (E). 50 mass% or less is preferable at the point of development residue suppression and the pattern deformation prevention at the time of image development.

  Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to methods described in, for example, JP-A-4-1222938, JP-A-2-28531, U.S. Pat. No. 4,916,210, European Patent 219294, and the like. Can be easily synthesized.

  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.

  In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.

  These surfactants may be added alone or in some combination.

(Pattern formation method)
The photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.

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) and developed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid 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.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ excimer laser, EUV (13 nm) An electron beam is preferred.

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

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

Synthesis Example 1 (Synthesis of polymer (RB-4) 3-oxoethyl-4-acetoxystyrene 40.42 g (1.0 mol), 4-acetoxystyrene 16.22 g, polymerization initiator V-601 (sum) 0.23 g (0.001 mol) of Kojun Pharmaceutical Co., Ltd. was dissolved in 200 g of ethylene glycol monoethyl ether acetate and dropped into the system at 80 ° C. over 4 hours under a nitrogen gas atmosphere. After stirring for 2 hours, the reaction solution was allowed to cool to room temperature and dropped into 3 L of hexane to precipitate a polymer.The filtered solid was dissolved in 200 ml of acetone, dropped again into 5 L of hexane, and the filtered solid was dried under reduced pressure. As a result, 48.14 g of 3-oxoethyl-4-acetoxystyrene / 4-acetoxystyrene copolymer was obtained.

  40.00 g of the copolymer obtained above, 40 ml of methanol, 100 ml of 1-methoxy-2-propanol and 1.5 ml of concentrated hydrochloric acid were added to the reaction vessel, heated to 80 ° C. and stirred for 5 hours. The reaction solution was allowed to cool to room temperature and dropped into 3 L of distilled water. The filtered solid was dissolved in 200 ml of acetone, dropped again into 3 L of distilled water, and the filtered solid was dried under reduced pressure to obtain 29.31 g of polymer (P-1). The weight average molecular weight by GPC was 8000, and the molecular weight dispersity (Mw / Mn) was 1.35.

  In a reaction vessel, 20.00 g of the polymer (P-1) was dissolved in 100 g of PGMEA, this solution was decompressed to 60 ° C. and 20 mmHg, and about 20 g of the solvent was distilled off together with water remaining in the system. The mixture was cooled to 0 ° C., 1.10 g of cyclohexyl ethyl vinyl ether, 0.80 g of ethyl vinyl ether and 0.02 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 2 hours. Thereafter, 0.03 g of triethylamine was added for neutralization, and 300 g of ethyl acetate and 100 g of water were added for washing operation three times. Thereafter, the amount of the solvent was adjusted to obtain a 30% by mass polymer solution. The weight average molecular weight by GPC was 9500, the molecular weight dispersity was 1.35, and the acetal protection rate of phenolic OH was 14.1% from 1H and 13C-NMR analysis.

  The polymers used in the following examples were synthesized in the same manner as in Synthesis Example 1 except that the monomers and vinyl ethers used were changed.

Examples 1-13 and Comparative Examples 1-2
The components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content concentration of 6.5% by mass. This solution was filtered through a 0.1 μm polytetrafluoroethylene filter to obtain a resist solution.

  Using a spin coater, the resist solution prepared as described above is uniformly applied on a silicon wafer that has been subjected to hexamethyldisilazane treatment, and is heated and dried at 120 ° C. for 90 seconds to form a resist film having a thickness of 0.15 μm. Formed. The resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.

[sensitivity]
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.). The minimum irradiation energy when resolving a 150 nm line (line: space = 1: 1) was defined as sensitivity.

[resolution]
The line size (line: space = 1: 1) in which separation resolution is recognized even when a part of the pattern is tilted is used as the limit resolution size at the irradiation dose showing the above sensitivity, and this is the resolution. Defined.

[Line edge roughness (LER)]
The distance from the reference line where there should be an edge using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.) at any 30 points in the length direction of 50 μm of the 150 nm line pattern at the irradiation dose showing the sensitivity described above. Was measured, the standard deviation was obtained, and 3σ was calculated. A smaller value means better performance.

[Dimension before collapse]
The pattern size (line: space = 1: 1) in which separation resolution was observed without any pattern collapse at the above-mentioned exposure doses was defined as the pre-fall dimension, and an index of the degree of collapse suppression. It was. A smaller value means better performance.

  Abbreviations used in Table 1 are shown below.

  [polymer]

[Basic compounds]
N-1: Trioctylamine N-2: 1,5-diazabicyclo [4.3.0] -5-nonene N-3: 2,4,6-triphenylimidazole

[Surfactant]
W-1: Megafuck F176 (manufactured by Dainippon Ink & Chemicals, Inc.)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
W-3: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-4: Polyoxyethylene lauryl ether

[solvent]
S-1: Propylene glycol monomethyl ether acetate S-2: Propylene glycol monomethyl ether S-3: Ethyl lactate S-4: Cyclohexanone

From Table 1, it can be seen that the photosensitive composition of the present invention is superior to the composition of the comparative example in all of sensitivity, resolution, LER, and pattern collapse performance.

Claims (5)

(A) A polymer having a repeating unit represented by the following general formula (I) and a repeating unit represented by the following general formula (II), which is decomposed by the action of an acid to increase the solubility in an alkali developer. And (B) a photosensitive composition comprising a compound capable of generating an acid upon irradiation with actinic rays or radiation.
In general formulas (I) and (II):
L represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group.
Z represents an alkyl group, a cycloalkyl group or an aralkyl group.
L ′ is the same as L.
W is the same as Z.
Z and L and W and L ′ may be bonded to each other to form a 5- or 6-membered ring.
However, Z and W are not the same.
R ₁ represents a hydrogen atom or a substituent.
R ₂ is the same as R ₁ .
However, R ₁ and R ₂ are not all hydrogen atoms.
R ₃ , R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom or a substituent.
a, b, c and d are 1 ≦ a, 1 ≦ b, 1 ≦ c, 1 ≦ d, and 2 ≦ (a + b) ≦ 5 and 2 ≦ (c + d) ≦ 5, respectively.   2. The photosensitive composition according to claim 1, wherein W is a group having a cycloalkyl group or an aryl group, and Z is an alkyl group.   W is C8 or more, and Z is C8 or less, The photosensitive composition of Claim 1 or 2 characterized by the above-mentioned.   The photosensitive composition according to claim 1, wherein the photosensitive composition is exposed with X-rays, electron beams or EUV.   A pattern forming method comprising: forming a photosensitive film from the photosensitive composition according to claim 1; and exposing and developing the photosensitive film.