JP2009053518A - Resist composition for electron beam, x-ray or euv and pattern-forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition which ensures reduced roughness and suppressed outgassing and a pattern-forming method using the resist composition, with respect to 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, and to provide a pattern-forming method that uses the photosensitive composition. <P>SOLUTION: The resist composition for an electron beam, X-ray or EUV contains a specific triarylsulfonium compound, having benzenesulfonic acid anions having specific substituents, and the pattern-forming method using the composition is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive composition whose properties change upon irradiation with actinic rays or radiation (electron beam, X-ray, EUV, UV, etc.), a compound used in the photosensitive composition, and the photosensitive composition. The present invention relates to the pattern forming method used. More specifically, a photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, a further photofabrication process, a lithographic printing plate, an acid curable composition, and the photosensitivity. The present invention relates to a compound used in a composition and a pattern forming method using the photosensitive composition.

  The chemically amplified resist composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and the acid-catalyzed reaction changes the solubility of the active radiation irradiated area and non-irradiated area in the developer. And a pattern forming material for forming a pattern on the substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed.

  A triphenylsulfonium salt is generally known as an acid generator that is a main constituent of a chemically amplified resist (see, for example, Patent Document 1).

  In addition, when an electron beam, X-ray, EUV light source or the like is used, exposure is performed under vacuum, so that low-boiling compounds such as solvents and resist materials decomposed by high energy volatilize and contaminate the exposure apparatus. Outgassing issues are becoming important. In recent years, various studies have been made on the reduction of outgas, and a radical trap that suppresses volatilization of a low-molecular compound by providing a topcoat layer (see, for example, Patent Document 2) or suppresses decomposition of a polymer. Various attempts such as adding an agent (see, for example, Patent Document 3) have been tried, and an contrivance for reducing outgas is also desired for an acid generator.

  As in Patent Documents 4 to 9, photoacid generators have been studied from various aspects.

  However, there are still many insufficient points, and a photosensitive composition that suppresses roughness and outgas is desired.

US Pat. No. 6,548,221 European Patent No. 1480078 specification US Pat. No. 6,680,157 JP 2006-78760 A JP 2006-171568 A JP 2005-37887 A Japanese Patent Laid-Open No. 2005-37888 US Published Patent Application No. 2007-0037091 JP 2006-215271 A

  The present invention provides an electron beam, X-ray or EUV resist composition having reduced roughness and suppressed outgas, and a pattern forming method using the resist composition.

The above problems have been solved by the following constitution of the sulfonium compound represented by the general formula (I).
(1) An electron beam, X-ray or EUV resist composition comprising a sulfonium compound (A) represented by the general formula (I).

In general formula (I),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent.
Z is a single bond or a divalent linking group.
R ^{14 to} R ¹⁸ each independently represents a hydrogen atom or a substituent. However, at least one of R ^{14 to} R ¹⁸ is an alkyl group or cycloalkyl group having 3 or more carbon atoms, and at least one of R ^{14 to} R ¹⁸ is an alkyl group or cyclohexane having 4 or more carbon atoms. It is an alkyl group.

(2) The resist composition for electron beam, X-ray or EUV according to (1) above, further comprising a resin which decomposes by the action of an acid and increases the solubility in an alkaline developer.
(3) The weight average molecular weight of the resin which decomposes by the action of an acid and increases the solubility in an alkali developer is 5000 or less, and is for electron beam, X-ray or EUV according to the above (2) Resist composition.
(4) The electron beam according to (2) or (3) above, wherein the repeating unit of the resin decomposes by the action of an acid and increases the solubility in an alkali developer, and has an aromatic group, X Resist composition for wire or EUV.

(5) The resist composition for electron beam, X-ray or EUV according to any one of the above (1) to (4), comprising a basic compound.
(6) The resist composition for electron beam, X-ray or EUV according to any one of the above (1) to (5), wherein the total solid content concentration is 0.2 to 4% by mass.
(7) A pattern forming method comprising a step of forming a resist film from the resist composition according to any one of (1) to (6) above, and exposing and developing the resist film.

  According to the present invention, it is possible to provide a resist composition excellent in roughness and outgas characteristics, and a pattern forming method using the resist composition.

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).

In the present invention, the compound (acid generator) that generates an acid upon irradiation with actinic rays or radiation useful for the photosensitive composition is a compound represented by the general formula (I) (hereinafter also referred to as an acid generator A1). ).
The photosensitive composition containing the acid generator A1 may be either a positive type or a negative type photosensitive composition.
The positive photosensitive composition of the present invention, more preferably the positive resist composition contains an acid generator (A) and a resin (B) that decomposes by the action of an acid and increases the solubility in an alkaline developer. If necessary, it further contains a dissolution inhibiting compound (E) having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer.

  The negative photosensitive composition of the present invention, more preferably the negative resist composition, is soluble in an alkaline developer by the action of an acid generator (A), a resin (C) soluble in an alkaline developer, and an acid. An acid cross-linking agent (D) that cross-links with other resins.

[1] Compound represented by general formula (I) (acid generator A1)

In general formula (I),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent.
Z is a single bond or a divalent linking group.
R ^{14 to} R ¹⁸ each independently represents a hydrogen atom or a substituent. However, at least one of R ^{14 to} R ¹⁸ is an alkyl group or cycloalkyl group having 3 or more carbon atoms, and at least one of R ^{14 to} R ¹⁸ is an alkyl group or cyclohexane having 4 or more carbon atoms. It is an alkyl 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. For example, a halogen atom, an alkyl group (cycloalkyl group, bicycloalkyl group, trimethyl group) Cycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, heterocyclic groups (also referred to as heterocyclic groups), cyano groups, nitro groups, carboxyl groups, 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, aminocarbonyl Amino group, alkoxycarbonylamino group, arylo Sicarbonylamino group, sulfamoylamino 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 Examples include a group, a ureido group, a boronic acid group (—B (OH) ₂ ), a phosphato group (—OPO (OH) ₂ ), a sulfato group (—OSO ₃ H), and other known substituents.

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.

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 a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, Aryl, cyano, carboxyl, alkoxy, aryloxy, acyloxy, carbamoyloxy, acylamino, aminocarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfamoylamino, alkyl And arylsulfonylamino group, alkylthio group, arylthio group, sulfamoyl group, alkyl and arylsulfonyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, imide group, silyl group, ureido It is.

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, an alkoxy group, an acyloxy group, an acylamino group, and an aminocarbonylamino group. , Alkoxycarbonylamino group, alkyl and arylsulfonylamino group, alkylthio group, sulfamoyl group, alkyl and arylsulfonyl group, alkoxycarbonyl group and carbamoyl 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 and an alkoxy group.

In general formula (I), at least one of R ^{1 to} R ¹³ preferably contains a proton donor group, and at least one of R ^{9 to} R ¹³ preferably contains a proton donor group.

The proton donor group in the present invention represents a group that can donate a hydrogen atom related to a hydrogen bond.
The proton donor group in the present invention, for example, an alcoholic hydroxyl _{group, -NH -, - NH 2,} -CONH -, - NHCO -, - SO 2 NH -, - NHSO 2 -, - SH , etc. with a group having a Yes, including these _{groups, -CONHCO -, - SO 2 NHCO} -, - SO 2 NHSO 2 - may be a group having a group, such as. It may be linear, or these groups may be included in the cyclic structure.
The alcoholic hydroxyl group means a hydroxyl group bonded to a carbon atom of an alkyl group.

When R ^{1 to} R ¹³ are substituents containing a proton donor group, R ^{1 to} R ¹³ are represented by —W—Y. Y is an alkyl group substituted with a proton donor group or an alkyl group having a proton donor group in the chain, and W is a single bond or a divalent linking group.

The alkyl group of Y is methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, 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. 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, and particularly preferably a single bond. is there.

When R ^{1 to} R ¹³ are substituents containing a proton donor group, the number of carbon atoms contained is preferably 2 to 10, more preferably 2 to 6, and particularly preferably 2 to 4. is there.
The substituent containing a proton donor group as R ^{1 to} R ¹³ may have two or more proton donor groups. The number of proton donor groups having a substituent including a proton donor group as R ^{1 to} R ¹³ is 1 to 6, preferably 1 to 3, and more preferably 1. It is preferable.
The number of proton donor groups possessed by the compound represented by the general formula (I) is 1 to 10, preferably 1 to 6, more preferably 1 in total for all of R ^{1 to} R ^13. From three to three.

Z represents a single bond or a divalent linking group, and 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 anion which the compound represented by general formula (I) has is an anion represented by the following general formula (X).

In general formula (X), R < ¹⁴ > -R < ¹⁸ > represents a hydrogen atom or a substituent each independently. However, at least one of R ^{14 to} R ¹⁸ is an alkyl group or cycloalkyl group having 3 or more carbon atoms, and at least one of R ^{14 to} R ¹⁸ is an alkyl group or cyclohexane having 4 or more carbon atoms. It is an alkyl group.

Examples of the alkyl group or cycloalkyl group having 4 or more carbon atoms of R ^{14 to} R ¹⁸ include n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, Nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl And boronyl group.
Specific examples of the alkyl group or cycloalkyl group having 3 or more carbon atoms of R ^{14 to} R ¹⁸ include propyl group, isopropyl group, cyclopropyl group in addition to the above specific examples of alkyl group or cycloalkyl group having 4 or more carbon atoms. The group can be mentioned.
The carbon number of the alkyl group or cycloalkyl group having 3 or 4 or more carbon atoms as R ^{14 to} R ¹⁸ is preferably 4 to 20, more preferably 4 to 12, particularly preferably 4 to 8.
R ¹⁴ , R ¹⁶ and R ¹⁸ have 3 or more carbon atoms, and one of them preferably has 4 or more carbon atoms, and particularly preferably R ¹⁶ has 4 or more carbon atoms.

The alkyl group or cycloalkyl group having 3 or more or 4 or more carbon atoms as R ^{14 to} R ¹⁸ may have a substituent. Examples of the substituent include a nitro group, a halogen atom (fluorine atom, chlorine Atom, bromine atom, iodine atom), carboxyl group, hydroxyl group, amino group, cyano group, alkoxy group, cycloalkyl group, aryl group, alkoxycarbonyl group, acyl group, alkoxycarbonyloxy group and the like. In addition, the cycloalkyl group as R < ¹⁴ > -R < ¹⁸ > may have an alkyl group as a cyclic substituent.
The number of carbon atoms of the substituent that the alkyl group or cycloalkyl group having 3 or more or 4 or more carbon atoms as R ^{14 to} R ¹⁸ may have is preferably 15 or less.
Note that the carbon number in the alkyl group or cycloalkyl group having 3 or more or 4 or more carbon atoms as R ^{14 to} R ¹⁸ does not include the carbon number of the substituent.

Other substituents as R ^{14 to} R ¹⁸ are not particularly limited, and examples thereof include a hydroxyl group, a nitro group, a halogen atom, and an alkoxy group.

  The total amount of the compound represented by the general formula (I) is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the resist composition. More preferably, it is 3-8 mass%.

  The molecular weight of the compound represented by the general formula (I) is preferably 1000 to 5000, particularly preferably 1500 to 4000, and particularly preferably 2000 to 3000.

The compound represented by the general formula (I) can be synthesized by a method in which a benzene derivative and a cyclic sulfoxide compound are condensed to form a sulfonium salt, and a protective group for a hydroxyl group is deprotected.
A synthesis method in the case of having a substituent containing a proton donor group on the benzene ring is shown below.

(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.
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.

  Although the specific example of a compound represented by general formula (I) below is shown, it is not limited to these.

[2] Compound that generates acid upon irradiation with actinic rays or radiation (acid generator A2)
The resist composition of the present invention may use other acid generators together with the acid generator A1. Hereinafter, another acid generator other than the acid generator A1 is referred to as an acid generator A2.
As the acid generator A2, a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization,
Known compounds that generate an acid upon irradiation with actinic rays or radiation used for photodecolorants, photochromic agents, or microresists of dyes, 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 to 30, preferably 1
~ 20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Z ⁻ represents a non-nucleophilic anion.

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

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

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

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

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

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

The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group , Hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 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 a compound (ZI-1) described later.
), (ZI-2) and (ZI-3).

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Examples of the 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.

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 Even more preferably, it is a sulfonium salt of fluorinated substituted alkane sulfonic acid, fluorine substituted benzene sulfonic acid or fluorine substituted imido acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, particularly preferred examples are given below.

The acid generator A2 can also be used alone or in combination of two or more.
The acid generator A2 is preferably 50% by mass or less, and more preferably 30% by mass with respect to the acid generator A1.

[3] Resin (B) which decomposes by the action of an acid and increases the solubility in an alkaline developer
Resins that are decomposed by an acid used in the positive resist composition of the present invention and have increased solubility in an alkaline developer have acid main chain or side chain, or both main chain and side chain. It is a resin having a group (acid-decomposable group) that decomposes by action to generate an alkali-soluble group. Among these, a resin having an acid-decomposable group in the side chain is more preferable.

A preferable group as the acid-decomposable group is a group in which a hydrogen atom of an alkali-soluble group such as a —COOH group or a —OH group is substituted with a group capable of leaving with an acid.
In the present invention, the acid-decomposable group is preferably an acetal group or a tertiary ester group.

  The base resin in the case where these acid-decomposable groups are bonded as side chains is an alkali-soluble resin having —OH or —COOH groups in the side chains. For example, the alkali-soluble resin mentioned later can be mentioned.

  The alkali dissolution rate of these alkali-soluble resins is preferably 170 A / second or more as measured with 0.261 N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferably, it is 330 A / second or more (A is angstrom).

  From this point of view, particularly preferred alkali-soluble resins are o-, m-, p-poly (hydroxystyrene) and copolymers thereof, hydrogenated poly (hydroxystyrene), halogen or alkyl-substituted poly (hydroxystyrene). Hydroxystyrene structural units such as a part of poly (hydroxystyrene), O-alkylated or O-acylated product, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, hydrogenated novolak resin, etc. An alkali-soluble resin containing a repeating unit having a carboxyl group such as (meth) acrylic acid or norbornenecarboxylic acid.

  Preferred examples of the repeating unit having an acid-decomposable group in the present invention include t-butoxycarbonyloxystyrene, 1-alkoxyethoxystyrene, (meth) acrylic acid tertiary alkyl ester, and the like. Alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate are more preferred.

  The component (B) used in the present invention is decomposed with an acid into an alkali-soluble resin as disclosed in European Patent No. 254853, JP-A-2-25850, JP-A-3-223860, JP-A-4-251259, and the like. It is possible to obtain an alkali-soluble resin monomer having a group capable of being decomposed or reacting with an acid-decomposable group by copolymerization with various monomers.

When the positive resist composition of the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, high energy light (EUV, etc.) having a wavelength of 50 nm or less, the resin of component (B) has an aromatic group. It is preferable to contain the repeating unit which has, and it is especially preferable that it is resin (B1) which has a hydroxystyrene repeating unit. More preferably, hydroxystyrene / hydroxystyrene copolymer protected with an acid-decomposable group and hydroxystyrene / (meth) acrylic acid tertiary alkyl ester are preferred.
Specific examples of the resin (B1) are shown below, but are not limited thereto.

  In the above specific example, tBu represents a t-butyl group.

  The content of the group that can be decomposed by an acid is determined by the number of groups (B) that can be decomposed by an acid in the resin and the number of alkali-soluble groups that are not protected by a group capable of leaving by an acid (S). B + S). The content is preferably 0.01 to 0.7, more preferably 0.05 to 0.50, and still more preferably 0.05 to 0.40.

  As the resin (B1) containing a hydroxystyrene repeating unit, a resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the general formula (III) is particularly preferable.

R ₀₁ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group.
L ₁ and L ₂ may be the same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alicyclic group or an aromatic ring group which may contain an alkyl group, a cycloalkyl group, or a hetero atom.
At least two of Q, M, and L ₁ may combine to form a 5-membered or 6-membered ring.
A represents a halogen atom, a cyano group, an acyl group, an alkyl group, an alkoxy group, an acyloxy group, or an alkoxycarbonyl group.
m and n independently represent an integer of 1 to 4. However, m and n are not 0 at the same time.

  Moreover, as resin (B1) containing a hydroxystyrene repeating unit, the repeating unit represented by general formula (II), the repeating unit represented by general formula (III), and the repeating unit represented by general formula (IV) It may be a resin having In this case, m = n = 0 may be used.

R ₀₁ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group.
B represents a halogen atom, a cyano group, an acyl group, an alkyl group, an alkoxy group, an acyloxy group or an alkoxycarbonyl group.
p represents an integer of 0 to 5.

  The substituent that the benzene ring in the repeating unit represented by the general formula (II) has is a group (acid-decomposable group) that is decomposed by the action of an acid to generate a hydroxyl group (an alkali-soluble group). Hydroxystyrene units are produced, and the resin is a resin with increased solubility in an alkaline developer.

R ₀₁ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, and preferably has 20 or less carbon atoms.
The alkyl group or cycloalkyl group in R ₀₁ preferably has 20 or less carbon atoms, and is a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group. Hexyl group, cyclohexyl group, octyl group, dodecyl group and the like. These groups may have a substituent, for example, alkoxy group, hydroxyl group, halogen atom, nitro group, acyl group, acyloxy group, acylamino group, sulfonylamino group, alkylthio group, arylthio group, aralkylthio group, thiophene. Examples include carbonyloxy groups, thiophenemethylcarbonyloxy groups, and heterocyclic residues such as pyrrolidone residues, and those having 8 or less carbon atoms are preferred. CF ₃ group, alkoxycarbonylmethyl group, alkylcarbonyloxymethyl group, hydroxymethyl group, alkoxymethyl group and the like are more preferable.
Examples of the halogen atom for R ₀₁ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.
As the alkyl group contained in the alkoxycarbonyl group in R _01, the same alkyl groups represented by R ₀₁ are preferred.

The alkyl group as L ₁ and L ₂ is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group. An octyl group can be preferably mentioned.
The cycloalkyl group as L ₁ and L ₂ is, for example, a cycloalkyl group having 3 to 15 carbon atoms, and specifically, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group can be preferably exemplified.
The aryl group as L ₁ and L ₂ is, for example, an aryl group having 6 to 15 carbon atoms, and specific examples thereof include a phenyl group, a tolyl group, a naphthyl group, and an anthryl group.
The aralkyl group as L ₁ and L ₂ has, for example, 6 to 20 carbon atoms, and examples thereof include a benzyl group and a phenethyl group.

The divalent linking group as M contains, for example, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, —OCO—, —COO—, or —CON (R ₀ ) —, and a plurality thereof. A linking group. R ₀ is a hydrogen atom or an alkyl group.

The alkyl group and cycloalkyl group as Q are the same as the above groups as L ₁ and L ₂ .
As the alicyclic group or aromatic ring group which may contain a hetero atom as Q,
Examples of the cycloalkyl group and aryl group as L ₁ and L ₂ described above include 3 to 15 carbon atoms.
Examples of the alicyclic group or aromatic ring group containing a hetero atom include thiirane, cyclothiolane, thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, thiazole, pyrrolidone, and the like. Is a structure generally called a heterocycle (a ring formed from carbon and a heteroatom, or a ring formed from a heteroatom).

As a 5-membered or 6-membered ring that may be formed by combining at least two of Q, M, and L ₁ , at least two of Q, M, and L ₁ are combined to form, for example, a propylene group and a butylene group In this case, a 5-membered or 6-membered ring containing an oxygen atom is formed.

As the group represented by -M-Q, 1 to 30 carbon atoms, more preferably from 5 to 20 carbon atoms, for _{example, -OC (L 1) (L} 2) a group represented by O-M-Q The following may be mentioned.

The acyl group as A is, for example, an acyl group having 2 to 8 carbon atoms. Specifically, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, a pivaloyl group, a benzoyl group and the like can be preferably exemplified. .
The alkyl group as A is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, and an octyl group. Can be preferably mentioned.
The alkoxy group as A is, for example, the above alkoxy group having 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. .
Examples of the acyloxy group or alkoxycarbonyl group as A include groups corresponding to the above acyl group and alkoxy group.

  Each of the above groups may have a substituent, and preferred substituents include a hydroxyl group, a carboxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkoxy group (methoxy group, ethoxy group, Propoxy group, butoxy group, etc.). As for the cyclic structure, examples of the substituent further include an alkyl group (preferably having 1 to 8 carbon atoms).

  m and n independently represent an integer of 0 to 4. m and n are each preferably 0 to 2, and more preferably 1.

  Specific examples of the repeating unit represented by the general formula (II) are shown below, but are not limited thereto.

  Specific examples of the repeating unit represented by the general formula (III) are shown below, but are not limited thereto.

R ₀₁ in the general formula (IV) independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, preferably having 20 or less carbon atoms, The same as R ₀₁ in (II) or (III).
The acyl group, alkyl group, alkoxy group, acyloxy group or alkoxycarbonyl group as B in the general formula (IV) is the same as each group as A in the general formula (II).
p represents an integer of 1 to 5, preferably 0 to 2, and more preferably 1.

  Specific examples of the repeating unit represented by the general formula (IV) are shown below, but are not limited thereto.

  The resin (B) may contain a repeating unit represented by the general formula (V).

Ra to Rc each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group or an alkyl group.
X ₁ represents a hydrogen atom or an organic group.

  The alkyl group as Ra to Rc is preferably an alkyl group having 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group.

The organic group as X ₁ preferably has 1 to 40 carbon atoms and may be an acid-decomposable group or a non-acid-decomposable group.

Examples of the non-acid-decomposable group include the same organic groups as those in the non-acid-decomposable group as R ₂ . (Because it is an organic group, halogen atoms are not included.)
Further, for example, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an alkyloxy group (excluding -O-tertiary alkyl), an acyl group, a cycloalkyloxy group, an alkenyloxy group, an aryloxy group, Examples thereof include an alkylcarbonyloxy group, an alkylamidomethyloxy group, an alkylamide group, an arylamidomethyl group, an arylamido group.
The non-acid-decomposable group is preferably an acyl group, an alkylcarbonyloxy group, an alkyloxy group, a cycloalkyloxy group, an aryloxy group, an alkylamidooxy group, or an alkylamido group, more preferably an acyl group or an alkylcarbonyl group. An oxy group, an alkyloxy group, a cycloalkyloxy group, and an aryloxy group;
In the non-acid-decomposable group, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, or a t-butyl group. As the alkyl group, those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferable, and as the alkenyl group, carbon number such as vinyl group, propenyl group, allyl group and butenyl group. Those having 2 to 4 carbon atoms are preferable, those having 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group are preferable as alkenyl groups, and phenyl group, xylyl group and toluyl group are preferable as aryl groups. And those having 6 to 14 carbon atoms such as cumenyl group, naphthyl group and anthracenyl group are preferable. As the alkoxy group, an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, an n-butoxy group, an isobutoxy group, and a sec-butoxy group is preferable.

As the organic group of the acid-decomposable group for X ₁ , for example, —C (R _11a ) (R _12a ) (R _13a ), —C (R _14a ) (R _15a ) (OR _16a ), —CO—OC ( R _11a ) (R _12a ) (R _13a ) can be mentioned.
R _{11a to} R _13a each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group. R _14a and R _15a each independently represents a hydrogen atom or an alkyl group. R _16a represents an alkyl group, a cycloalkyl group, an alkenyl group,
Represents an aralkyl group or an aryl group. Two of R _11a , R _12a and R _13a , or two of R _14a , R _15a and R _16a may be bonded to form a ring.
Note that a group having an acid-decomposable group can be introduced into X ₁ by modification. In this way, X ₁ introduced with the acid decomposable group is, for example, as follows.
-[C ( _R17a ) ( _R18a )] _p- CO-OC ( _R11a ) ( _R12a ) ( _R13a ) _R17a and _R18a each independently represents a hydrogen atom or an alkyl group. p is an integer of 1 to 4.

The organic group as X ₁ is preferably an acid-decomposable group having at least one cyclic structure selected from alicyclic, aromatic and bridged alicyclic, and an aromatic group (particularly a phenyl group). Or a structure containing an alicyclic or bridged alicyclic structure represented by the following general formulas (pI) to (pVI).

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{22 to} R ₂₅ Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

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

The alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

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

Examples of the substituent that the alicyclic hydrocarbon group may have include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Can be mentioned. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
The alkyl group, alkoxy group, and alkoxycarbonyl group may further have a substituent. Examples of such a substituent include an alkoxy group having 1 to 4 carbon atoms (methoxy group, ethoxy group, butoxy group). Group), hydroxy group, oxo group, alkylcarbonyl group (preferably 2 to 5 carbon atoms), alkylcarbonyloxy group group (preferably 2 to 5 carbon atoms), alkoxycarbonyl group (preferably 2 to 5 carbon atoms) And halogen atoms (chlorine atom, bromine atom, fluorine atom, etc.).

In addition, the resin (B) contains an alkali-soluble group such as a phenolic hydroxyl group, a carboxyl group, a sulfonic acid group, a hexafluoroisopropanol group (—C (CF ₃ ) ₂ ) in order to maintain good developability for an alkali developer. Other suitable polymerizable monomers may be copolymerized so that (OH) can be introduced, and other hydrophobic polymerizable monomers such as alkyl acrylates and alkyl methacrylates may be copolymerized to improve film quality. May be.

The content of the repeating unit represented by the general formula (II) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and particularly preferably 10 to 40 mol% in all repeating units constituting the resin. It is.
The content of the repeating unit represented by the general formula (III) is preferably 40 to 90 mol%, more preferably 45 to 80 mol%, particularly preferably 50 to 75 mol% in all repeating units constituting the resin. It is.

The content of the repeating unit represented by the general formula (IV) is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, particularly preferably 15 to 30 mol% in all repeating units constituting the resin. It is.
The content of the repeating unit represented by the general formula (V) is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, and particularly preferably 0 to 10 mol% in all repeating units constituting the resin. It is.

The content of the repeating unit having an alkali-soluble group such as a hydroxyl group, a carboxy group, or a sulfonic acid group is preferably 1 to 99 mol%, more preferably 3 to 95 mol%, particularly preferably in all repeating units constituting the resin. 5 to 90 mol%.
The content of the repeating unit having an acid-decomposable group is preferably 3 to 95 mol%, more preferably 5 to 90 mol%, and particularly preferably 10 to 85 mol% in all repeating units constituting the resin.

  Resins are synthesized by reacting a precursor of an acid-decomposable group with an alkali-soluble resin as described in European Patent No. 254,533, JP-A-2-258500, No. 3-223860 and No. 4-251259. It can be synthesized by a known synthesis method such as a method or a method of copolymerizing a monomer having an acid-decomposable group with various monomers.

The weight average molecular weight of the resin (B1) is preferably 5000 or less, more preferably 1,000 to 5,000, still more preferably 1,500 to 4,000, and particularly preferably, as a polystyrene conversion value by the GPC method. 2,000 to 3,000.
The dispersity (Mw / Mn) of the resin (B1) is preferably 1.0 to 3.0, more preferably 1.05 to 2.0, and even more preferably 1.1 to 1.7. .

  Moreover, you may use resin (B1) in combination of 2 or more types.

  Specific examples of the resin (B1) are shown below, but are not limited thereto.

  When irradiating the positive resist composition of the present invention with ArF excimer laser light, the resin of component (B) has a monocyclic or polycyclic alicyclic hydrocarbon structure, and is decomposed by the action of an acid. A resin (B2) that increases the solubility in an alkali developer is preferred.

Resin (B2) having a monocyclic or polycyclic alicyclic hydrocarbon structure, decomposed by the action of an acid, and increased in solubility in an alkali developer (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) ) Is selected from the group consisting of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and repeating units represented by the following general formula (II-AB) It is preferable that the resin has at least one selected from the above.

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In general formula (II-AB),
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

The general formula (II-AB) is represented by the following general formula (II-AB1) or general formula (II-
AB2) is more preferred.

In general formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA ′. —R ₁₇ ′ represents an alkyl group or a cycloalkyl group. At least two of R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
Here, R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.
n represents 0 or 1.

In the general formulas (pI) to (pV), the alkyl group in R _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. , N-butyl group, sec-butyl group, t-butyl group and the like.

The cycloalkyl group in R _{11 to} R ₂₅ or the cycloalkyl group formed by Z and the carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These cycloalkyl groups may have a substituent.

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

These alkyl groups and cycloalkyl groups may further have a substituent. As further substituents for alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (2 to 2 carbon atoms). 6). The above alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have a substituent. Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pV) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

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

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

In the general formula (pA), R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. A single bond is preferable.
Rp1 represents any one of the general formulas (pI) to (pV).

  The repeating unit represented by the general formula (pA) is most preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Specific examples of the repeating unit represented by the general formula (pA) are shown below.

In the above structural formulas, Rx represents H, CH ₃ , CF ₃ or CH ₂ OH, and Rxa and Rxb each independently represents an alkyl group having 1 to 4 carbon atoms.

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

As the alkyl group for R ₁₁ ′ and R ₁₂ ′, a linear or branched alkyl group having 1 to 10 carbon atoms is preferable, for example, methyl group, ethyl group, n-propyl group, isopropyl group, linear group Or a branched butyl group, pentyl group, hexyl group, heptyl group, etc. are mentioned.

The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include those similar to the cycloalkyl groups represented by R _{12 to} R _{25 in} the general formulas (pI) to (pVI).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

  In the resin (B2), the group decomposed by the action of an acid is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV), a general formula (II- It can be contained in at least one repeating unit among the repeating unit represented by AB) and the repeating unit of the copolymerization component described later.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) are atomic groups for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

  The resin (B2) preferably has a repeating unit having a lactone group. As the lactone group, any group having a lactone structure can be used, but a group having a 5- to 7-membered ring lactone structure is preferred, and a bicyclo structure or spiro is added to the 5- to 7-membered ring lactone structure. Those in which other ring structures are condensed to form a structure are preferred. The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). . Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and a specific lactone structure is used. This improves line edge roughness and development defects.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n ₂ is 0 to
Represents an integer of 4. When n ₂ is an integer of 2 or more, a plurality of Rb ₂ may be the same or different, and a plurality of Rb ₂ may be bonded to form a ring.

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-16), R _{13 in the} above general formula (II-AB1) or (II-AB2) may be used. A group having a group represented by general formula (LC1-1) to (LC1-16) at least one of 'to R ₁₆ ' (for example, R _{5 of} -COOR ₅ is represented by formula (LC1-1) to ( And a repeating unit represented by the following general formula (AI).

In general formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Examples of the alkyl group for Rb ₀ include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, and a t-butyl group. The alkyl group for Rb ₀ may have a substituent. Preferable substituents that the alkyl group of Rb ₀ may have include, for example, a hydroxyl group and a halogen atom.

Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb0 is preferably a hydrogen atom or a methyl group.

Ab is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express. Preferably, it is a linking group represented by a single bond or -Ab ₁ -CO _2- .
Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl residue, an adamantyl residue, or a norbornyl residue.

  V represents a group represented by any one of the general formulas (LC1-1) to (LC1-16).

The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.
Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

The resin (B2) preferably has a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The polar group is preferably a hydroxyl group or a cyano group.
Here, the hydroxyl group as a polar group forms an alcoholic hydroxyl group.
Examples of the alicyclic hydrocarbon structure substituted with a polar group include structures represented by the following general formula (VIIa) or (VIIb).

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

  The group represented by the general formula (VIIa) is preferably a dihydroxy body or a monohydroxy body, and more preferably a dihydroxy body.

The repeating unit having a group represented by the general formula (VIIa) or (VIIb) includes at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2). Having the group represented by the above general formula (VIIa) or (VIIb) (for example, R _{5 in} —COOR ₅ represents a group represented by the general formula (VIIa) or (VIIb)), or the following general group Mention may be made of the repeating units of the formula (AIIa) or (AIIb).

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

  Specific examples of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group represented by the general formula (AIIa) or (AIIb) will be given below, but the present invention is not limited thereto.

  Resin (B2) may have a repeating unit represented by the following general formula (VIII).

In General Formula (VIII), Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

  The resin (B2) preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By having this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Any of the bonded repeating units is preferable, and the linking group may have a monocyclic or polycyclic hydrocarbon structure. Most preferred are acrylic acid and methacrylic acid.

  The resin (B2) may have a repeating unit having 1 to 3 groups represented by the following general formula (F1). This improves line edge roughness performance.

In general formula (F1), R _{50 to} R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
Rx represents a hydrogen atom or an organic group (preferably an acid-decomposable protecting group, an alkyl group, a cycloalkyl group, an acyl group, or an alkoxycarbonyl group).

The alkyl group of R _{50 to} R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, etc., preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl group or a trifluoromethyl group. be able to.
R _{50 to} R ₅₅ are preferably all fluorine atoms.

  Examples of the organic group represented by Rx include an acid-decomposable protective group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. , 1-alkoxyethyl group is preferable.

  Preferred examples of the repeating unit having a group represented by the general formula (F1) include a repeating unit represented by the following general formula (F2).

In General Formula (F2), Rx represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rx may have include a hydroxyl group and a halogen atom.
Fa represents a single bond or a linear or branched alkylene group, preferably a single bond.
Fb represents a monocyclic or polycyclic hydrocarbon group.
Fc represents a single bond or a linear or branched alkylene group, preferably a single bond or a methylene group.
F ₁ represents a group represented by the general formula (F1).
p ₁ is an integer of 1 to 3.

  The cyclic hydrocarbon group in Fb is preferably a cyclopentyl group, a cyclohexyl group, or a norbornyl group.

  Specific examples of the repeating unit having the structure of the general formula (F1) are shown below.

  Resin (B2) adjusts dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, such as resolution, heat resistance, and sensitivity, in addition to the above repeating structural units For this purpose, various repeating structural units can be included.

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

Thereby, the performance required for the resin (B2), in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

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

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

  In the resin (B2), the content molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required performance of the resist, resolving power, heat resistance, sensitivity. It is set appropriately in order to adjust etc.

The following are mentioned as a preferable aspect of resin (B2).
(1) What contains the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by said general formula (pI)-(pV) (side chain type). Those having a repeating unit of (meth) acrylate preferably having a structure of (pI) to (pV).
(2) Those having a repeating unit represented by formula (II-AB) (main chain type). However, in (2), for example, the following can be further mentioned.
(3) Those having a repeating unit represented by the general formula (II-AB), a maleic anhydride derivative structure and a (meth) acrylate structure (hybrid type).

  In the resin (B2), the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol% in all repeating structural units. is there.

  In the resin (B2), the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is preferably 25 to 70 mol% in all repeating structural units, More preferably, it is 35-65 mol%, More preferably, it is 40-60 mol%.

  In the resin (B2), the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 in all repeating structural units. ˜50 mol%.

In the resin (B2), the content of the repeating unit having a lactone group is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, still more preferably 25 to 60 mol% in all repeating structural units.
In the resin (B2), the content of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, even more preferably in all repeating structural units. Is 5 to 20 mol%.

In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. 99 mol% with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon represented by (pV) and the repeating unit represented by the above general formula (II-AB) The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.
The resin (B2) is preferably one in which all of the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units may be methacrylate, all of the repeating units may be acrylate, or a mixture of methacrylate / acrylate, but the acrylate repeating unit is preferably 50 mol% or less of the total repeating units.

  More preferably, the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 25 to 50%, the repeating unit having the lactone structure is 25 to 50%, and the polarity is A ternary copolymer having 5 to 30% of repeating units having an alicyclic hydrocarbon structure substituted with a group, or a repeating unit having a structure represented by a carboxyl group or general formula (F1) It is a quaternary copolymer having 20%.

The resin (B2) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as that used in the resist composition of the present invention. Thereby, the generation of particles during storage can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50 to 100 ° C.

The weight average molecular weight of the resin of component (B) is preferably 1,000 to 200,000 as a polystyrene conversion value by the GPC method. By making the weight average molecular weight 1,000 or more, heat resistance and dry etching resistance can be improved, and by making the weight average molecular weight 200,000 or less, developability can be improved. And since a viscosity becomes low, film forming property can be improved. The molecular weight is more preferably 1,500 to 50,000, and still more preferably 2,000 to 30,000. By adjusting the molecular weight, it is possible to achieve both heat resistance, resolution, development defects, and the like of the composition.
The dispersity (Mw / Mn) of the component (B) resin is preferably 1.0 to 3.0, more preferably 1.0 to 2.5, and still more preferably 1.0 to 1.6. It is. The line edge roughness performance can be improved by adjusting the degree of dispersion to an appropriate range.

  In the positive resist composition of the present invention, the blending amount of the resin of the component (B) according to the present invention in the entire composition is preferably 40 to 99.9% by mass, more preferably 50 to 99 in the total solid content. It is 80 mass%, More preferably, it is 80-96 mass%.

[4] Resin soluble in alkali developer (C)
Hereinafter, it is also referred to as “component (C)” or “alkali-soluble resin”.
The alkali dissolution rate of the alkali-soluble resin is preferably 20 A / second or more as measured with 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferably, it is 200 A / second or more (A is angstrom).

  Examples of the alkali-soluble resin used in the present invention include novolak resin, hydrogenated novolak resin, acetone-pyrogalol resin, o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene, hydrogenated polyhydroxystyrene, and halogen. Alternatively, alkyl-substituted polyhydroxystyrene, hydroxystyrene-N-substituted maleimide copolymer, o / p- and m / p-hydroxystyrene copolymer, partially O-alkylated product of hydroxyl group of polyhydroxystyrene (for example, 5- 30 mol% O-methylated product, O- (1-methoxy) ethylated product, O- (1-ethoxy) ethylated product, O-2-tetrahydropyranylated product, O- (t-butoxycarbonyl) methylated product, etc.) Or O-acylated product (for example, 5 to 30 mol) O-acetylated product, O- (t-butoxy) carbonylated product, etc.), styrene-maleic anhydride copolymer, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, carboxyl group-containing methacrylic acid Examples thereof include, but are not limited to, resins and derivatives thereof, and polyvinyl alcohol derivatives.

Particularly preferred alkali-soluble resins are novolak resins and o-polyhydroxystyrene,
m-polyhydroxystyrene, p-polyhydroxystyrene and copolymers thereof, alkyl-substituted polyhydroxystyrene, partially O-alkylated or O-acylated product of polyhydroxystyrene, styrene-hydroxystyrene copolymer, α -A methylstyrene-hydroxystyrene copolymer.

  The novolak resin is obtained by subjecting a predetermined monomer as a main component to addition condensation with an aldehyde in the presence of an acidic catalyst.

  The weight average molecular weight of the alkali-soluble resin is generally 2000 or more, preferably 5000 to 200000, and more preferably 5000 to 100,000.

  Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.

  These (C) alkali-soluble resins in the present invention may be used in combination of two or more.

The amount of the alkali-soluble resin used is generally 40 to 97 with respect to the total solid content of the composition.
It is 60 mass%, Preferably it is 60-90 mass%.

[5] Dissolution inhibitor (D) having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer.
Hereinafter, it is also referred to as “component (D)” or “dissolution inhibitor compound”.
(D) As a dissolution-inhibiting compound having a molecular weight of 3000 or less that decomposes by the action of an acid and increases its solubility in an alkaline developer, the transmittance of 220 nm or less is not lowered, so Proceeding of SPIE, 2724,355 (1996) An alicyclic or aliphatic compound containing an acid-decomposable group is preferred, such as a cholic acid derivative containing an acid-decomposable group described in 1). Examples of the acid-decomposable group and alicyclic structure are the same as those described above for the alicyclic hydrocarbon-based acid-decomposable resin.

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

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

The addition amount of the dissolution inhibiting compound is preferably 3 to 50% by mass with respect to the total solid content of the composition.
More preferably, it is 5 to 40% by mass.

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

[6] Acid crosslinking agent (E) that crosslinks with the alkali-soluble resin by the action of an acid
Hereinafter, it is also referred to as “component (E)” or “crosslinking agent”.
A crosslinking agent is used in the negative resist composition of the present invention.

Any crosslinking agent can be used as long as it is a compound that crosslinks a resin soluble in an alkaline developer by the action of an acid, but the following (1) to (3) are preferred.
(1) Hydroxymethyl, alkoxymethyl, and acyloxymethyl forms of phenol derivatives.
(2) A compound having an N-hydroxymethyl group, an N-alkoxymethyl group, or an N-acyloxymethyl group.
(3) A compound having an epoxy group.

  The alkoxymethyl group preferably has 6 or less carbon atoms, and the acyloxymethyl group preferably has 6 or less carbon atoms.

  Of these crosslinking agents, particularly preferred are listed below.

In the formula, L ^{1 to} L ⁸ may be the same or different and each represents a hydrogen atom, a hydroxymethyl group, a methoxymethyl group, an ethoxymethyl group, or an alkyl group having 1 to 6 carbon atoms.
The crosslinking agent is generally used in an added amount of 3 to 70% by mass, preferably 5 to 50% by mass in the total solid content of the resist composition.

[7] Basic compound (F)
The resist composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating.

  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 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, 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.

In the formula, 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, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  Further, at least one nitrogen-containing compound selected from an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group can be exemplified. .

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

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

  The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound or ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. Etc. The substitution position of the substituent may be any of the 2-6 positions. The number of substituents may be any in the range of 1 to 5.

It is preferable to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  In the amine compound having a sulfonic acid ester group and the ammonium salt compound having a sulfonic acid ester group, the sulfonic acid ester group may be any of alkyl sulfonic acid ester, cycloalkyl group sulfonic acid ester, and aryl sulfonic acid ester. In the case of an alkyl sulfonate ester, the alkyl group has 1 to 20 carbon atoms, in the case of a cycloalkyl sulfonate ester, the cycloalkyl group has 3 to 20 carbon atoms, and in the case of an aryl sulfonate ester, the aryl group has 6 carbon atoms. ~ 12 are preferred. Alkyl sulfonic acid ester, cycloalkyl sulfonic acid ester, and aryl sulfonic acid ester may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid. An ester group is preferred.

It is preferable to have at least one oxyalkylene group between the sulfonate group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  The amine compound having a phenoxy group is prepared by reacting a primary or secondary amine having a phenoxy group with a haloalkyl ether by heating, and then adding an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide or tetraalkylammonium. It can be obtained by extraction with an organic solvent such as ethyl acetate or chloroform. Alternatively, after reacting by heating a primary or secondary amine and a haloalkyl ether having a phenoxy group at the end, an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide, or tetraalkylammonium is added, and then ethyl acetate, It can be obtained by extraction with an organic solvent such as chloroform.

  These basic compounds are used alone or in combination of two or more. However, when the amount of component (B) used is 0.05% by mass or more, the basic substance may or may not be used. When using a basic compound, the amount of its use is 0.001-10 mass% normally based on solid content of a resist composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

[8] Fluorine-based and / or silicon-based surfactant (G)
The resist composition of the present invention further includes any one of fluorine-based and / or silicon-based surfactants (fluorine-based surfactants and silicon-based surfactants, surfactants containing both fluorine atoms and silicon atoms). Or it is preferable to contain 2 or more types.

  When the resist composition of the present invention contains fluorine and / or a silicon-based surfactant, when using an exposure light source of 250 nm or less, particularly 220 nm or less, good sensitivity and resolution, and less adhesion and development defects. A 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-based 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 resist composition (excluding the solvent). .

[9] Organic solvent (H)
The resist 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 are used, and the solid content concentration is usually 0.05 to 20% by mass, preferably 0.1 to 8% by mass, and more. Preferably, 0.2 to 4% by mass of a resist composition is prepared.

[10] Other additives (I)
If necessary, the resist composition of the present invention further contains a dye, a plasticizer, a surfactant other than the component (G), a photosensitizer, a compound that promotes solubility in a developer, and the like. Can do.

  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.

  A 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 the component (B) or the resin of the component (C). 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, a surfactant other than the above (G) fluorine-based and / or silicon-based surfactant 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.

[11] Pattern formation method (J)
The resist 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, a photosensitive composition is formed by applying and drying a resist composition on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by an appropriate application method such as a spinner or a coater. To do. In addition, a known antireflection film can be applied in advance.
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.

(Immersion exposure)
When the resist composition of the present invention is subjected to immersion exposure, the resist composition is preferably used at a film thickness of 30 to 250 nm, more preferably at a film thickness of 30 to 100 nm, from the viewpoint of improving resolution. It is preferable. Such a film thickness can be obtained by setting the solid content concentration in the resist composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The total solid concentration in the resist composition is generally 1 to 10% by mass, more preferably 1 to 8% by mass, and still more preferably 1.0 to 6.0% by mass.

When the resist composition of the present invention is subjected to immersion exposure, the resist composition is prepared by dissolving the above components in a predetermined organic solvent, preferably the above mixed solvent, and applying the solution on a predetermined support as follows. Use.
That is, the resist composition can be formed to an arbitrary thickness (usually 30 to 500 nm) by an appropriate coating method such as a spinner or a coater on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements. ). After application, the resist film is washed with immersion water as necessary. The washing time is usually 5 seconds to 5 minutes.
Subsequently, the resist composition applied by spin or baking is dried to form a photosensitive film (hereinafter also referred to as a resist film), and then passed through a mask or the like for pattern formation, and exposed (immersed) through immersion water. Exposure). For example, the exposure is performed in a state where the space between the resist film and the optical lens is filled with the immersion liquid. Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally. After exposure, the resist film is washed with immersion water as necessary. The time is usually 5 seconds to 5 minutes. Subsequently, spin or / and baking is preferably performed, and development and rinsing are performed to obtain a good pattern. It is preferable to perform the said baking, and baking temperature is 30-300 degreeC normally. The time from the exposure to the baking process should be short.
Here, the exposure light is preferably far ultraviolet rays having a wavelength of 250 nm or less, more preferably 220 nm or less. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), and X-rays.
Incidentally, it is considered that the change in performance observed when the resist is applied to immersion exposure is derived from the contact of the resist surface with the immersion liquid.

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

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

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

In order to prevent the resist film from coming into direct contact with the immersion liquid between the resist film made of the resist composition of the present invention and the immersion liquid, an immersion liquid hardly soluble film (hereinafter also referred to as “top coat”) is provided. It may be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers.

When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.
The resolution is improved when there is no difference in refractive index between the topcoat and the immersion liquid. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the immersion liquid, so that the top coat for ArF immersion exposure is close to the refractive index of water (1.44). Is preferred. A thin film is more preferable from the viewpoint of transparency and refractive index.

When an organic solvent is used as the immersion liquid, it is preferable to use a water-soluble top coat.

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

<Synthesis of Compound (P-3)>
(1) Synthesis of dibenzothiophene-S-oxide 20.0 g of dibenzothiophene was suspended in 80.0 ml of trifluoroacetic acid at room temperature. Thereto, 12.4 ml of 30% aqueous hydrogen peroxide was slowly added dropwise while cooling with ice so that the reaction temperature was maintained at around 60 ° C. After the addition, the reaction solution is stirred at room temperature for 30 minutes. After the reaction, the reaction solution is added to 1000 ml of water to precipitate crystals. The crystals are filtered and washed with water. The obtained crystals were recrystallized with ace and nitrile to obtain 19.2 g of dibenzothiophene-S-oxide.
¹ H-NMR (400 MHz, CDCl ₃ ) σ7.51 (t, 2H), 7.59 (t, 2H), 7.81 (d, 2H), 8.00 (d, 2H)

(2) Synthesis of 5- (4- (2-hydroxyethyl) phenyl) benzothiophenium 2,6-diisopropyl-4-cyclohexyl benzene sulfonate dibenzo synthesized in (1) above under ice cooling Add 10.0 g of thiophene-S-oxide into diphosphorus pentoxide / methanesulfonic acid = 9/1 (30 g) and add 10 ml of 2-phenylethyl acetate. After stirring at room temperature for 6 hours, pour into ice water. The resulting aqueous solution is filtered and 23 g of potassium iodide is added. The precipitated crystals are collected by filtration to obtain 11.1 g of 5- (4- (2-acetoxyethyl) phenyl) dibenzothiophenium iodide. 11.1 g of the obtained 5- (4- (2-acetoxyethyl) phenyl) dibenzothiophenium iodide is dissolved in 200 ml of methanol, and 10.7 g of tetramethylammonium hydroxide (20% aqueous solution) is added. After stirring at room temperature for 2 hours, 13.8 g of 2,6-diisopropyl-4-cyclohexylbenzenebenzenesulfonic acid is added, and the mixture is further stirred at room temperature for 30 minutes. Further, 3.9 g of silver acetate is added to the reaction solution and stirred at room temperature for 1 hour. After filtering the reaction solution, the mother liquor is distilled off under reduced pressure. The obtained crystals are dissolved in chloroform and washed three times with water. Chloroform was distilled off under reduced pressure and recrystallized with ethyl acetate / acetate and nitrile = 5/1. This gives 5- (4- (2-hydroxyethyl) phenyl) benzothiophenium 2,6-diisopropyl-4-cyclohexyl benzene sulfonate P-3 (7.1 g).
NMR: δ 1.20 (d, 6H), 1.26 (tt, 1H), 1.37-1.47 (m, 4H), 1.75 (dm, 1H), 1.80-1.88 (m, 4H), 2.49 (tt, 1H), 2.78 (m, 2H), 3.71 (t, 2H), 4.68 (m, 2H), 7.02 (s, 2H), 7.29 (d, 2H), 7.51 (t, 2H), 7.64 (d, 2H), 7.76 (t, 2H), 8.14 (d, 2H), 8.22 (d, 2H)

<Resin synthesis>
The following resin E-1 was synthesized as follows. Other resins were synthesized in the same manner.

In a reaction vessel, 162.2 g (1.0 mol) of 4-acetoxystyrene (Honshu Chemical) was dissolved in 400 ml of tetrahydrofuran, and nitrogen gas was allowed to flow through the system while stirring. Thereto, 23.0 g (0.1 mol) of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the reaction solution was heated to 65 ° C. After stirring with heating for 10 hours, the reaction solution was allowed to cool to room temperature and dropped into 5 L of hexane to precipitate the polymer. The filtered solid was dissolved in 600 ml of acetone, dropped again into 5 L of hexane, and the filtered solid was dried under reduced pressure to obtain 150.6 g of a (3-methoxy-4-acetoxystyrene)-(4-acetoxystyrene) copolymer. It was.
To the reaction vessel, 130 g of the polymer obtained above, 500 ml of methanol, 500 ml of 1-methoxy-2-propanol, 2.0 ml of concentrated hydrochloric acid and 30 ml of distilled water were added, 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 120 ml of acetone, dropped again into 3 L of distilled water, and the filtered solid was dried under reduced pressure to obtain 75.1 g of polymer 1a. The weight average molecular weight by GPC was 3500, and the molecular weight dispersity was 1.51.

In a reaction vessel, 30 g of the polymer 1a obtained above was dissolved in 100 g of PGMEA, this solution was decompressed to 60 mm 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 20 ° C., 18.35 g of 2- (4-cyclohexyl) phenoxyethyl vinyl ether and 1.0 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 1 hour. Thereafter, 1.16 g of triethylamine was added for neutralization, and 40 g of ethyl acetate and 40 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 of this polymer by GPC was 4000, the molecular weight dispersity was 1.55, and the composition ratio was 70/30 in order from the left of the figure from ¹ H and ¹³ C-NMR analysis.

Other resins were synthesized in the same manner.
The structure, molecular weight, and dispersity of the resin (B) used in the examples are shown. The number on the right side of the repeating unit represents the molar ratio.

E-1: weight average molecular weight; 3000, dispersity; 1.52
E-2: weight average molecular weight; 2500, dispersity; 1.60
E-3: weight average molecular weight; 2500, dispersity; 1.64
E-4: weight average molecular weight; 3000, dispersity; 1.52
E-5: weight average molecular weight; 2500, dispersity; 1.60
E-6: weight average molecular weight; 2500, dispersity; 1.64
E-7: weight average molecular weight; 3000, dispersity; 1.57
E-8: weight average molecular weight; 2200, dispersity; 1.55
E-9: weight average molecular weight; 3500, dispersity; 1.54
E-10: weight average molecular weight; 2500, dispersity; 1.64

[EUV exposure: Examples 1 to 11 and Comparative Example 1]
The components shown in Table 1 are dissolved in a solvent, and this is filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a positive resist solution having a solid content concentration of 3.0% by mass, and evaluated as follows. It was. In addition, the addition amount of surfactant is 0.1 mass% with respect to the total solid in a resist solution.

<Resist evaluation>
The prepared positive resist solution is uniformly coated on a silicon substrate subjected to hexamethyldisilazane treatment using a spin coater, and is heated and dried on a hot plate at 120 ° C. for 60 seconds to form a 70 nm resist film. Formed.

[Sensitivity and γ value]
The obtained resist film was subjected to surface exposure using EUV light (wavelength 13 nm) while changing the exposure amount by 0.5 mJ in the range of 0 to 10.0 mJ, and further baked at 110 ° C. for 90 seconds. Then, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure amount was measured to obtain a sensitivity curve.
In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. The larger the γ value, the better the dissolution contrast.

[Roughness]
The line width is measured using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.) at any 32 points in the length direction of 10 μm of the 50 nm line pattern at the radiation amount showing the above sensitivity, and the standard deviation is calculated. The 3σ was calculated.

[Outgas performance: Film thickness fluctuation rate after exposure]
Irradiate a dose of 2.0 times the dose (mJ / cm ² ) with the sensitivity determined by performing surface exposure with EUV light, measure the film thickness after exposure (before post-heating), and use the following formula: From this, the rate of change from the unexposed film thickness was determined.
Film thickness variation rate (%) = [(film thickness at unexposed−film thickness after exposure) / film thickness at unexposed] × 100

  The evaluation results are shown in Table 1 below.

The symbols for each component are as follows.
[Acid generator]
The acid generator is exemplified above.

  The acid generator (A-1) used in the comparative example is the following compound.

[Basic compounds]
C-1: 2,4,5-triphenylimidazole C-2: Triphenylsulfonium acetate C-3: N-hydroxyethylpiperidine C-4: 2,6-diisopropylaniline C-6: Tripentylamine C-10 : N-phenyldiethanolamine

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

〔solvent〕
A1: Propylene glycol monomethyl ether acetate B1: Propylene glycol monomethyl ether

  From the results of Table 1, it can be seen that the resist composition of the present invention is superior in roughness and outgas performance in comparison with the composition of the comparative example in the property evaluation by irradiation with EUV light.

  In the resist composition of the present invention, similar results can be obtained in patterning by KrF and electron beam exposure and also as a negative resist composition.

Claims (7)

A resist composition for electron beam, X-ray or EUV, comprising a compound represented by formula (I).
In general formula (I),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent.
Z is a single bond or a divalent linking group.
R ^{14 to} R ¹⁸ each independently represents a hydrogen atom or a substituent. However, at least one of R ^{14 to} R ¹⁸ is an alkyl group or cycloalkyl group having 3 or more carbon atoms, and at least one of R ^{14 to} R ¹⁸ is an alkyl group or cyclohexane having 4 or more carbon atoms. It is an alkyl group.   2. The resist composition for electron beam, X-ray or EUV according to claim 1, further comprising a resin which decomposes by the action of an acid and increases the solubility in an alkaline developer.   3. The resist composition for electron beam, X-ray or EUV according to claim 2, wherein the weight average molecular weight of the resin decomposed by the action of an acid and increased in solubility in an alkaline developer is 5000 or less.   The resist composition for electron beam, X-ray or EUV according to claim 2 or 3, which has an aromatic group in the repeating unit of the resin which is decomposed by the action of an acid and increases the solubility in an alkali developer. object.   The resist composition for electron beam, X-ray or EUV according to claim 1, comprising a basic compound.   6. The resist composition for electron beam, X-ray or EUV according to claim 1, wherein the total solid content concentration is 0.2 to 4% by mass.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 1; and exposing and developing the resist film.