JP5299031B2 - Radiation sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation sensitive resin composition which, as a chemically amplified resist, is high in transparency to radiation and superior in resolution and is not only superior in dry-etching resistance, sensitivity, and pattern shape or the like, but also remarkably improves the yield of semiconductor elements by suppressing the occurrence of development defects during microfabrication. <P>SOLUTION: The radiation sensitive resin composition includes a resin (A) including an acid dissociable group, a compound (B) which generates an acid by irradiation with active light or radiation, and a compound (C) which includes a cyclodextrin skeleton and a fluorine atom in a molecular structure and includes &le;6,000 average molecular weight calculated from<SP>1</SP>H NMR. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a polymer for semiconductor resist and a radiation-sensitive resin composition. More specifically, a chemically amplified resist useful for microfabrication using various types of radiation such as deep ultraviolet rays typified by KrF excimer lasers and ArF excimer lasers, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. The present invention relates to a radiation-sensitive resin composition and a semiconductor resist polymer that can be suitably used as a semiconductor resist.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, lithography technology capable of microfabrication at a level of 0.20 μm or less is required. The use of radiation having a shorter wavelength is being studied.
Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, X-rays, and electron beams. Among these, KrF excimer laser (wavelength 248 nm) Alternatively, an ArF excimer laser (wavelength 193 nm) has been attracting attention.

As a resist suitable for irradiation with such an excimer laser, a component having an acid-dissociable functional group and a component that generates acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “acid generator”). )) And a resist utilizing the chemical amplification effect (hereinafter referred to as “chemically amplified resist”) have been proposed.
In this resist, the acid-dissociable functional group present in the polymer is dissociated by the action of the acid generated by exposure, and the polymer has an acidic group. As a result, the exposed area of the resist film is reduced. This utilizes the phenomenon of being easily soluble in an alkali developer.

  In conventional chemically amplified resists, a phenolic polymer is often used for a resist using a KrF excimer laser, and a (meth) acrylate polymer having an aliphatic ring is used for a resist using an ArF excimer laser (patents). Reference 1). The selection of polymers and acid generators has improved resist performance such as dry etching resistance, sensitivity, resolution, pattern shape, etc., but the reason for worsening the yield of the resulting semiconductor elements as microfabrication progresses Therefore, development defects during resist pattern processing have become a major problem in recent years. Therefore, it is highly transparent to radiation represented by far-ultraviolet rays, and not only has excellent dry etching resistance, sensitivity, resolution, pattern shape, etc., but also does not cause development defects at the time of microfabrication, so that the semiconductor device can be manufactured at a high yield. Development of a chemically amplified radiation sensitive resin composition that can be produced is required.

JP-A-7-234511

  The present invention has been made in view of the above circumstances, has high transparency to radiation, is excellent not only in basic physical properties as a resist such as sensitivity and resolution, but also reduces development defects during microfabrication, and a semiconductor. An object of the present invention is to provide a radiation-sensitive resin composition object capable of producing an element with a high yield.

The radiation-sensitive resin composition of the present invention is (A) an acid dissociation having a structure represented by the following formula (3) as a repeating unit having a group that dissociates a protecting group with an acid and develops alkali solubility of the resin. Functional group-containing resin (hereinafter also simply referred to as “resin (A)”),
(B) a compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as “acid generator (B)”), and (C) has a cyclodextrin skeleton and a fluorine atom in the molecular structure, and , A compound having an average molecular weight of 6000 or less calculated from ¹ H NMR (hereinafter also referred to as “compound (C)”),
It is characterized by containing.

In the radiation-sensitive resin composition of the present invention, the compound (C) preferably has 3% by weight or more of fluorine atoms per molecule.
In the radiation-sensitive resin composition of the present invention, the compound (C) preferably has a structure represented by the following formula (1).

(In Formula (1), R ¹ is independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an acyl group having 2 to 20 carbon atoms, an aralkyl group, or an alkenyl group. And at least one of R ¹ is a group represented by the following formula (2), n is 6, 7 or 8.)

(In the formula (2), ^{R 2} is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an acyl group having 2 to 20 carbon atoms, an aralkyl group or an alkenyl group, R ³ Represents a perfluoroalkyl group having 1 to 10 carbon atoms, and * represents a bond.)

Further the radiation-sensitive resin composition of the present invention, the compound (C) is preferably 5% or more relative to the total R ¹ in the formula (1) is a group table by the formula (2).
Furthermore, in the radiation sensitive resin composition of the present invention, the content of the compound (C) is 0.01% by weight to 20% by weight when the content of the polymer (A) is 100% by weight. preferable.

  The radiation sensitive resin composition of the present invention is a chemically amplified resist that is sensitive to actinic radiation, particularly far ultraviolet rays typified by ArF excimer laser (wavelength 193 nm), and resist performance such as transparency to radiation, resolution, and sensitivity. It is extremely effective in reducing development defects, and can be used very favorably in the manufacture of semiconductor devices that are expected to be miniaturized in the future.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be specifically described. However, the present invention is not limited to the following embodiment, and is within the scope of the present invention without departing from the spirit of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on knowledge.

<Resin (A)>
The resin (A) in the present invention is an acid dissociable group, that is, a repeating unit having a group that causes the protecting group portion to dissociate by an acid and express the alkali solubility of the resin (hereinafter referred to as “repeating unit (A-1)”). ) Is essential, and preferably has a repeating unit having a lactone skeleton or a cyclic ester structure (hereinafter referred to as “repeating unit (A-2)”) in order to enhance alkali solubility.
The repeating unit (A-1) has a structure represented by the following formula (3).

(In Formula (3), R ³ is a hydrogen atom or a methyl group, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ⁵ And R ⁶ are each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or bonded to each other and bonded to each other. And a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms.)

Examples of the alkyl group having 1 to 4 carbon atoms in the formula (3) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and a t-butyl group. Can do.
Examples of the alicyclic hydrocarbon group having 4 to 20 carbon atoms include groups derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; norbornane, tricyclodecane, tetracyclododecane, adamantane, and the like. And groups derived from polycyclic alicyclic hydrocarbons. These groups may be groups substituted by one or more of the aforementioned alkyl groups.

  Preferred monomers used for forming the repeating unit (A-1) include, for example, (meth) acrylic acid t-butyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-isopropyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester (Meth) acrylic acid 1-isopropyl-1-cyclohexyl ester, (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid 2-n-propyladamantyl-2-yl ester, (meth) a 2-Isopropyladamantyl-2-yl ester of lauric acid, 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid, 1- (adamantan-1-yl) -1- (meth) acrylic acid Examples include ethyl ethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylpropyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-ethylpropyl ester, and the like. it can.

The resin (A) may contain only one type of repeating unit (A-1) having an acid dissociable group, or may contain two or more types.
The content rate of this repeating unit (A-1) is 10-90 mol% normally, More preferably, it is 20-80 mol%, when all the repeating units in resin (A) are 100 mol%. If the content of the repeating unit (A-1) is less than 10 mol%, the solubility of the developer after exposure may be adversely affected and resolution may be deteriorated. Moreover, there exists a possibility that the adhesiveness to the board | substrate of the resist pattern obtained as it is 80 mol% or more may become inadequate.

  Among the repeating units (A-2), those having a lactone skeleton include repeating units represented by the following formulas (4-1) to (4-9).

(In the formula, R ⁴ is a hydrogen atom, a methyl group or a trifluoromethyl group, and R ^{5 to} R ⁷ are each independently a hydrogen atom, a substituted or unsubstituted linear or branched chain having 1 to 4 carbon atoms. An alkyl group, a substituted or unsubstituted linear or branched alkoxyl group having 1 to 4 carbon atoms or a substituted or unsubstituted linear or branched fluorinated alkyl group having 1 to 4 carbon atoms, A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 4 carbon atoms, —R ⁸ —O— or —R ⁸ —COO— (wherein R ⁸ represents a divalent carbon atom having 1 to 4 carbon atoms). X represents a methylene group, an ethylene group or —O—, and p, q, r and s are each independently an integer of 1 or 2.)

In these formulas, examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ^{5 to} R ⁷ , R ⁹ and R ¹⁰ described later include, for example, a methyl group, an ethyl group, n- Examples thereof include a propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a t-butyl group, and the like, as a linear or branched alkoxyl group having 1 to 4 carbon atoms. Examples include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group and the like. Examples of the linear or branched fluorinated alkyl group having 1 to 4 carbon atoms include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with fluorine atoms. Moreover, as a substituent of these groups, a hydroxyl group, an amino group, etc. are preferable.

Specific examples of a preferable monomer that gives the repeating unit (A-2) having a lactone skeleton include (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7. ] Non-2-yl ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) Acrylic acid-5-oxo-4-oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa- Tricyclo [5.2.1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, ( (Meth) acrylic acid-4- Toxicarbonyl-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] octa- 2-yl ester, (meth) acrylic acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran -4-yl ester, (meth) acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth ) Acrylic acid-4-propyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-3-yl Ester, (meth) acrylic acid-2,2-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic Acid-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran -3-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl -5-oxotetrahydrofuran-2-ylmethyl ester, (meth) a Like acrylic acid-4,4-dimethyl-5-oxo-tetrahydrofuran-2-yl methyl ester.

  Among the repeating units (A-2), those having a cyclic ester structure include repeating units represented by the following formulas (5-1) to (5-10).

Wherein R ⁴ is a hydrogen atom, a methyl group or a trifluoromethyl group, and R ⁹ and R ¹⁰ are each independently a hydrogen atom, a substituted or unsubstituted C 1-4 linear or branched An alkyl group, a substituted or unsubstituted linear or branched alkoxyl group having 1 to 4 carbon atoms or a substituted or unsubstituted linear or branched fluorinated alkyl group having 1 to 4 carbon atoms, A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 4 carbon atoms, —R ¹¹ —O— or —R ¹¹ —COO— (wherein R ¹¹ represents a divalent carbon atom having 1 to 4 carbon atoms). X represents a methylene group, an ethylene group or -O-, and t, u, v and w are each independently an integer of 0 or 1).

Resin (A) may contain only 1 type of this repeating unit (A-2), and may contain 2 or more types.
The content of the repeating unit (A-2) is preferably 5 to 85 mol%, more preferably 10 to 70 mol%, when all the repeating units in the resin (A) are 100 mol%. More preferably, it is 15-60 mol%. When the content of this repeating unit (A-2) is less than 5 mol%, developability and exposure margin tend to be deteriorated. On the other hand, when this content rate exceeds 85 mol%, there exists a tendency for the solubility to the solvent of resin (A) to deteriorate, and the resolution to deteriorate.

  The resin (A) in the present invention may contain one or more repeating units other than the repeating units (A-1) and (A-2) (hereinafter referred to as “other repeating units”).

Other monomers that form the repeating unit include, for example, (meth) acrylic acid-bicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-bicyclo [2.2.2]. Oct-2-yl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] dec-7-yl ester, (meth) acrylic acid-tetracyclo [6.2.1.13 ^{, 6} . 0 ^2,7 ] dodec-9-yl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] dec-1-yl ester, (meth) acrylic acid-tricyclo [3.3. ^1.1,7 ] dec-2-yl ester, dicyclopentenyl (meth) acrylate, adamantylmethyl (meth) acrylate, carboxynorbornyl (meth) acrylate, carboxytricyclodecacate (meth) acrylate (Meth) acrylic acid esters having a bridged hydrocarbon skeleton such as nyl, carboxytetracycloundecanyl (meth) acrylate;

Styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2-t-butoxycarbonylethyloxy) styrene 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene, 2-hydroxy-α-methylstyrene, 3-hydroxy-α-methylstyrene, 4-hydroxy-α-methylstyrene, 2-methyl-3-hydroxystyrene 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene, 2,4,6- Trihydroxystyrene, 4-t-butoxystyrene, 4-t Butoxy-α-methylstyrene, 4- (2-ethyl-2-propoxy) styrene, 4- (2-ethyl-2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- ( 1-ethoxyethoxy) -α-methylstyrene, phenyl (meth) acrylate, benzyl (meth) acrylate, acenaphthylene, 5-hydroxyacenaphthylene, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-hydroxy-6 Vinylnaphthalene, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, 1-naphthylmethyl (meth) acrylate, 1-anthryl (meth) acrylate, 2-anthryl (meth) acrylate, 9-anthryl (meth) Acrylate, 9-anthrylmethyl (meth) acrylate, 1-vinyl Compounds having an aromatic hydrocarbon skeleton such as lupyrene;

  Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 1-methyl (meth) acrylate Propyl, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, ( (Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 4-methoxycyclohexyl, (meth) acrylic acid 2-cyclopentyloxycarbonylethyl, (meth) acrylic acid 2-cyclohexyloxycarbonylethyl, (meth) 2- (4-Methoxycyclohexyl) acrylic acid No bridged hydrocarbon skeleton such as aryloxycarbonyl ethyl (meth) acrylate;

  α-hydroxymethyl acrylate esters such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate; (meth) acrylonitrile , Α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesaconitrile, citraconitrile, itaconnitrile, and other unsaturated nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide , Fumaramide, mesaconamide, citraconic amide, itaconic amide, etc .; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinyl Other nitrogen-containing vinyl compounds such as lysine and vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, etc. Unsaturated carboxylic acids (anhydrides); 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, Carboxyl group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as (meth) acrylic acid 4-carboxycyclohexyl;

1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, methylene glycol Di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di (meth) Acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate, 1,3-bis (2 -Hydroxypropyl) benzenedi ( It can be mentioned polyfunctional monomer motor) acrylate and the like.
The resin (A) in the present invention may contain one or more of these other repeating units regardless of the type.

  In addition, the resin (A) in the present invention is, for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit, radicals such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can manufacture by superposing | polymerizing in a suitable solvent using a polymerization initiator in presence of a chain transfer agent as needed.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, Cycloalkanes such as norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene; ethyl acetate Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, Ethers such as diethoxyethanes It can be mentioned. These solvents can be used alone or in admixture of two or more.
The reaction temperature in the above polymerization is usually 40 to 150 ° C., preferably 50 to 120 ° C., and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

Moreover, Mw by GPC method of resin (A) in this invention is although it does not specifically limit, Preferably it is 1,000-100,000, More preferably, it is 1,000-30,000, More preferably, it is 1,000-20. , 000. If the Mw of the resin (A) is less than 1,000, the heat resistance when used as a resist tends to decrease. On the other hand, if the Mw exceeds 100,000, the developability of the resist tends to decrease.
Moreover, ratio (Mw / Mn) of Mw of resin (A) and Mn by GPC method is normally 1-5, Preferably it is 1-3.

Moreover, in resin (A), content of the low molecular-weight component derived from the monomer used when preparing this resin (A) is 0.1 with respect to 100 mass% of this resin in conversion of solid content. It is preferably at most mass%, more preferably at most 0.07 mass%, still more preferably at most 0.05 mass%. When this content is 0.1% by mass or less, it is possible to reduce the amount of the eluate in the immersion exposure liquid such as water that is in contact with the immersion exposure. Furthermore, foreign matters are not generated in the resist during resist storage, and coating unevenness does not occur during resist application, and the occurrence of defects during resist pattern formation can be sufficiently suppressed.
Examples of the low molecular weight component derived from the monomer include a monomer, a dimer, a trimer, and an oligomer, and can be a component having an Mw of 500 or less. The components having an Mw of 500 or less can be removed by the following purification method. The amount of the low molecular weight component can be analyzed by high performance liquid chromatography (HPLC) of the resin.
In addition, resin (A) is so preferable that there is little content of impurities, such as a halogen and a metal, Thereby, the sensitivity at the time of setting it as a resist, resolution, process stability, a pattern shape, etc. can be improved further.
Examples of the purification method of the resin (A) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation, etc. Can be mentioned.

  Moreover, in this invention, resin (A) can be used individually or in mixture of 2 or more types.

<Acid generator (B)>
The acid generator (B) in the present invention generates an acid by irradiation such as exposure, and the acid contained in the repeating unit (A-1) present in the resin component by the action of the acid generated by exposure. The dissociable group is dissociated (the protecting group is eliminated). As a result, the exposed portion of the resist film becomes readily soluble in an alkali developer, and has a function of forming a positive resist pattern.
As such an acid generator (B), what contains the compound (henceforth "compound (6)") represented by following formula (6) is preferable.

(Wherein R ¹² represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or A linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms, wherein R ¹³ is a linear or branched alkyl group or alkoxyl group having 1 to 10 carbon atoms, or 1 to 10 carbon atoms; A linear, branched, or cyclic alkanesulfonyl group, wherein R ¹⁴ is independently a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group, or a substituted group. An optionally substituted naphthyl group, or two R ¹⁴ bonded to each other to form a divalent group having 2 to 10 carbon atoms, k is an integer of 0 to 2, X ⁻ represents the formula: R ¹⁵ C _n F _2n SO ₃ ⁻ , R ¹⁵ SO ₃ ⁻ (wherein R ¹⁵ represents a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and n is an integer of 1 to 10) Or an anion represented by the following formula (7-1) or (7-2), and j is an integer of 0 to 10.)

(Wherein R ¹⁶ is, independently of each other, a linear or branched fluorinated alkyl group having 1 to 10 carbon atoms, or S in which two R ¹⁶ are bonded to each other and bonded to each other) You may form a C2-C10 cyclic structure with an atom.)]

In the formula (6), examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ¹² , R ¹³ and R ¹⁴ include a methyl group, an ethyl group, an n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group and the like can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

  Examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group , N-decyloxy group and the like. Of these alkoxyl groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

  Examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms include, for example, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, 2 -Methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, n-octyloxy A carbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group, etc. can be mentioned. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms of R ¹³ include, for example, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a tert. -Butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n-nonanesulfonyl group, n-decanesulfonyl Group, cyclopentanesulfonyl group, cyclohexanesulfonyl group and the like. Of these alkanesulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

  Moreover, as j, 0-2 are preferable.

In the formula (6), examples of the optionally substituted phenyl group represented by R ¹⁴ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 2,3-dimethylphenyl group, 2, 4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4- Substituted with a phenyl group such as ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms Phenyl group; these phenyl group or alkyl-substituted phenyl group can be substituted with hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group. It can be exemplified group, an alkoxycarbonyl group, or the like group substituted with at least one group of one or more such alkoxycarbonyloxy groups.

  Among the substituents for the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1- Examples thereof include a linear, branched or cyclic alkoxyl group having 1 to 20 carbon atoms such as a methylpropoxy group, a t-butoxy group, a cyclopentyloxy group and a cyclohexyloxy group.

Examples of the alkoxyalkyl group include 2 to 21 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. And linear, branched or cyclic alkoxyalkyl groups.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, and a 1-methylpropoxycarbonyl group. , T-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like, and straight chain, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms.

  Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as cyclopentyloxycarbonyl group and cyclohexyloxycarbonyl.

Examples of the optionally substituted naphthyl group for R ¹⁴ include 1-naphthyl group, 2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 6-methyl-1-naphthyl group, 7-methyl-1-naphthyl group, 8-methyl-1-naphthyl group, 2,3-dimethyl -1-naphthyl group, 2,4-dimethyl-1-naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6-dimethyl-1-naphthyl group, 2,7-dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4-dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl group, 3,6-dimethyl-1-naphthyl group, 3,7-dimethyl- 1-naphthyl group, 3,8-dimethyl-1-na Tyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group, 2-naphthyl group, 1-methyl-2-naphthyl group, 3-methyl A naphthyl group substituted with a naphthyl group such as a 2-naphthyl group or 4-methyl-2-naphthyl group or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms; these naphthyl group or alkyl Examples include a group in which a substituted naphthyl group is substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Can do.

The divalent group having 2 to 10 carbon atoms formed by bonding two R ¹⁴ to each other is preferably a 5- or 6-membered ring, particularly preferably a 5-membered ring, together with the S atom in the formula (6). It is desirable to form a ring (that is, a tetrahydrothiophene ring).

Examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxy group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. Examples thereof include a carbonyl group and an alkoxycarbonyloxy group.
As R ¹⁴ in the formula (6), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ¹⁶ are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom. A divalent group or the like is preferable.

The —C _n F _2n — group in the case where X ⁻ in formula (6) is R ¹⁵ C _n F _2n SO ₃ ^— is a perfluoroalkylene group having n carbon atoms, but this group is linear Or may be branched. Here, n is preferably 1, 2, 4 or 8.
Further, examples of the hydrocarbon group which may having 1 to 12 carbon atoms which may be substituted in R ^15, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a bridged alicyclic hydrocarbon group.
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group N-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl group Etc.

R ¹⁶ in the case where X ⁻ is an anion represented by the above formula (7-1) or (7-2) has fluorine atoms independent of each other and has 1 to 10 carbon atoms. It may be a linear or branched alkyl group, or two R ¹⁶ may be bonded to each other to have a fluorine atom and be a divalent organic group having 2 to 10 carbon atoms, In that case, the divalent organic group may have a substituent.
In the formula (7-1) or (7-2), when R ¹⁶ is a linear or branched alkyl group having 1 to 10 carbon atoms, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group Group, nonafluorobutyl group, dodecafluoropentyl group, perfluorooctyl group and the like.
When R ¹⁶ is a divalent organic group having 2 to 10 carbon atoms, a tetrafluoroethylene group, a hexafluoropropylene group, an octafluorobutylene group, a decafluoropentylene group, an undecafluorohexylene group, etc. Can be mentioned.

Accordingly, preferred anions X ⁻ in the above formula (6) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hepta. 2-yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, the following formula (8-1) to And anions represented by (8-7).

  Preferred examples of the formula (6) include triphenylsulfonium trifluoromethanesulfonate, tri-tert-butylphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium. Trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate,

  Triphenylsulfonium perfluoro-n-butanesulfonate, tri-tert-butylphenylsulfonium perfluoro-n-butanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-butanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium per Fluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-butanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-butanesulfonate,

  Triphenylsulfonium perfluoro-n-octane sulfonate, tri-tert-butylphenylsulfonium perfluoro-n-octane sulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-octane sulfonate, 4-methanesulfonylphenyl-diphenylsulfonium per Fluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-octane sulfonate,

  Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2 .1] Hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl)- 1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoro Ethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2. ] Hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1,2,2-tetrafluoroethanesulfonate,

  Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1-difluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 4-methanesulfonylphenyl -Diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- ( Bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroeta Sulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2′-yl) -1,1-difluoroethanesulfonate, represented by the following formulas B1 to B15 And the like.

  In the present invention, compound (6) can be used alone or in combination of two or more.

  Examples of the radiation sensitive acid generator other than the compound (6) that can be used as the acid generator (B) (hereinafter referred to as “other acid generator”) include, for example, an onium salt compound, A halogen-containing compound, a diazoketone compound, a sulfone compound, a sulfonic acid compound, and the like can be given. Examples of these other acid generators include the following.

Onium salt compounds:
Examples of the onium salt compound include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.
Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta-2. -Yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis ( 4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2- Te La tetrafluoroethane sulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

Halogen-containing compounds:
Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound.
Specific examples of halogen-containing compounds include (trichloromethyl such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine. ) -S-triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

Diazo ketone compounds:
Examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like.
Specific examples of the diazo ketone include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2, naphthoquinonediazide of 2,3,4,4′-tetrahydroxybenzophenone. -4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane Examples include 2-naphthoquinonediazide-5-sulfonic acid ester.

Sulfone compounds:
Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds of these compounds.
Specific examples of the sulfone compound include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like.

Sulfonic acid compounds:
Examples of the sulfonic acid compounds include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates.
Specific examples of the sulfonic acid compounds include benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept- 5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2 .1] Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2. 1] Hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyl Xyl) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic imidononafluoro-n-butanesulfonate, 1,8-naphthalenedicarboxylic Examples include acid imido perfluoro-n-octane sulfonate.

  Among these other acid generators, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta- 2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-Butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2 -Tetraph Oro ethanesulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethane sulfonate,

Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2 1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate and the like are preferable.
These other acid generators can be used alone or in admixture of two or more.

In the present invention, the total amount of the compound (6) and other acid generator used is usually 0.1 to 100 parts by mass of the resin (A) from the viewpoint of ensuring the sensitivity and developability as a resist. 20 parts by mass, preferably 0.5 to 10 parts by mass. In this case, if the total amount used is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, when the total amount used exceeds 20 parts by mass, the transparency to radiation is lowered, and it tends to be difficult to obtain a rectangular resist pattern.
Moreover, the usage-amount of other acid generators is 80 mass% or less normally with respect to 100 mass% of the sum total of the acid generator 1 and another acid generator, Preferably it is 60 mass% or less.

<Compound (C)>
The compound (C) is a compound having a cyclodextrin skeleton and a fluorine atom in the molecular structure, and is a component having an action of suppressing development defect generation at the time of resist fine processing.
The compound (C) may be a mixture of two or more compounds having different structures, and the average molecular weight is 6000 or less, preferably 1000 to 4000. The average molecular weight of the compound (C) can be calculated and calculated based on the composition determined from the ratio of the integral value of the proton of the cyclodextrin skeleton and the proton of the substituent, using ¹ H-NMR.
Moreover, it is preferable that a compound (C) has 3 weight% or more of fluorine atoms with respect to 1 molecule, More preferably, it is 10 weight% or more.

The compound (C) preferably has a structure represented by the above formula (1). In the above formula (1), the alkyl group represented by R ¹ or R ² may have a substituent, preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and in the alkyl chain. You may have an oxygen atom, a sulfur atom, and a nitrogen atom. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group And a branched alkyl group such as a linear alkyl group such as isopropyl group, isobutyl group, t-butyl group, neopentyl group, and 2-ethylhexyl group. More preferred are methyl group, ethyl group, n-propyl group, n-butyl group, and tert-butyl group.
R ^1, the aryl group as R ^2, may have a substituent and is preferably an aryl group having 6 to 14 carbon atoms, for example, R ¹ to phenyl group, a naphthyl ^group, R ² The acyl group as may have a substituent and is preferably an acyl group having 1 to 10 carbon atoms, and examples thereof include a formyl group, an acetyl group, a propionyl group, a butyryl group, and a pareryl group. .
The aralkyl group as R ¹ and R ² is preferably an aralkyl group having 7 to 20 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a naphthylmethyl group, and a naphthylethyl group.
Examples of the alkenyl group as R ¹ and R ² include a group having a double bond at an arbitrary position of the alkyl group. Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C10) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 10).
n represents an integer of 6 to 8. The compounds having n of 6, 7, and 8 are α-, β-, and γ-cyclodextrin, respectively.

<Nitrogen-containing compound (D)>
The radiation-sensitive resin composition of the present invention preferably contains a nitrogen-containing compound (D) as an additive. The nitrogen-containing compound (D) is a component that controls the diffusion phenomenon of the acid generated from the acid generator upon exposure in the resist film and suppresses an undesirable chemical reaction in the non-exposed region. By mix | blending such an acid diffusion control agent, the storage stability of the radiation sensitive resin composition obtained improves. In addition, the resolution as a resist is further improved, and it is possible to suppress changes in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to post-exposure heat treatment, and an extremely excellent process stability. Things are obtained.

Examples of the nitrogen-containing compound (D) include tertiary amine compounds, other amine compounds, amide group-containing compounds, urea compounds, and other nitrogen-containing heterocyclic compounds.
Examples of the tertiary amine compound include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n-butylamine Di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. (Cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, Tri-n-nonylamine, tri-n-decylamine, cyclohex Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine, tricyclohexylamine; substituted alkylamines such as 2,2 ′, 2 ″ -nitrotriethanol; aniline, N-methylaniline, N, N— Dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N- Phenyldiethanolamine, 2,6-diisopropylaniline and the like are preferable.

  Examples of the other amine compounds include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl ester Benzene], bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like are preferable.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, and Nt. -Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)- (-)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxy Piperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbo Lupiperazine, Nt-butoxycarbonylpiperidine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt- Butoxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N'- Di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycal Nyl-1,12-diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N , N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like are preferable.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n-butyl. Thiourea and the like are preferable.

  Examples of the other nitrogen-containing heterocyclic compounds include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl- Imidazoles such as 2-methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4- Pyridines such as phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2 Piperazine such as -hydroxyethyl) piperazine In addition, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetyl Preferred are morpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like.

The nitrogen-containing compound (D) can be used alone or in combination of two or more.
The amount of the acid diffusion controller [nitrogen-containing compound (D)] is usually 15 parts by mass or less, preferably 10 parts by mass or less, more preferably 5 parts by mass or less with respect to 100 parts by mass of the resin (A). It is. In this case, when the compounding amount of the acid diffusion controller exceeds 15 parts by mass, the sensitivity as a resist tends to decrease. If the amount of the acid diffusion controller is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

<Solvent (E)>
The radiation-sensitive resin composition of the present invention is usually dissolved in a solvent so that the total solid content concentration is usually 1 to 50% by mass, preferably 1 to 25% by mass. A composition solution is prepared by filtering with a filter having a pore size of about 0.2 μm.

  Examples of the solvent (E) include 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3- Linear or branched ketones such as dimethyl-2-butanone, 2-heptanone, 2-octanone; cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, Cyclic ketones such as isophorone; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl Propylene glycol monoalkyl ether acetates such as ether acetate, propylene glycol mono-i-butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; methyl 2-hydroxypropionate, 2-hydroxypropionic acid Ethyl, 2-hydroxypropionate n-propyl, 2-hydroxypropionate i-propyl, 2-hydroxypropionate n-butyl, 2-hydroxypropionate i-butyl, 2-hydroxypropionate sec-butyl, 2-hydroxy Alkyl 2-hydroxypropionates such as t-butyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Methyl propionate, other 3-alkoxy propionic acid alkyl such as ethyl 3-ethoxypropionate,

  n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether , Propylene glycol monoethyl Ether, propylene glycol mono-n-propyl ether, toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, Ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol Cole monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, etc. Can do.

Among these, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone and the like are preferable. .
These solvents (E) can be used alone or in admixture of two or more.

<Additive (F)>
In addition to the compound (C) and the nitrogen-containing compound (D), various additives such as alicyclic additives, surfactants, sensitizers, and the like are included in the radiation-sensitive resin composition of the present invention. Can be blended.

The said alicyclic additive is a component which shows the effect | action which further improves dry etching tolerance, a pattern shape, adhesiveness with a board | substrate, etc.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α. -Butyrolactone ester, 1,3-adamantane dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane; t-butyl deoxycholic acid, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, 2-deoxycholic acid 2- Cyclohexyloxyethyl, deoxy Deoxycholic acid esters such as 3-oxocyclohexyl cholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester of deoxycholic acid; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, Lithocholic acid esters such as 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, tetrahydropyranyl lithocholic acid, mevalonolactone ester of lithocholic acid; dimethyl adipate, diethyl adipate, dipropyl adipate, din adipate - butyl, alkyl carboxylic acid esters such as adipate t- butyl or 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^{2, 5} 1 ^7,10 ] dodecane and the like. These alicyclic additives can be used alone or in admixture of two or more.

The surfactant is a component having an action of improving coating properties, striation, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd.), Megafax F171, F173 (manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC430, FC431 ( Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-105, SC-106 (Asahi Glass Co., Ltd.) And the like. These surfactants can be used alone or in admixture of two or more.

The sensitizer absorbs radiation energy and transmits the energy to the acid generator (B), thereby increasing the amount of acid produced. The radiation-sensitive resin composition It has the effect of improving the apparent sensitivity.
Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used alone or in admixture of two or more.
In addition, by blending a dye or pigment, the latent image of the exposed area can be visualized, and the influence of halation during exposure can be alleviated, and by blending an adhesion aid, adhesion to the substrate can be improved. it can.
Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like.

<Method for forming resist pattern>
The radiation sensitive resin composition of the present invention is particularly useful as a chemically amplified resist. In the above chemically amplified resist, the acid-dissociable group in the resin (A) is dissociated by the action of the acid generated from the acid generator by exposure to generate a carboxyl group. The solubility in the developer is increased, and the exposed portion is dissolved and removed by the alkali developer, and a positive resist pattern is obtained.
When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the resin composition solution is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating, cast coating, or roll coating. A resist film is formed by coating on a substrate such as a wafer, and this resist is formed so that a predetermined resist pattern is formed after a heat treatment (hereinafter referred to as “PB”) in some cases. Expose the coating. The radiation used at that time is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, etc., depending on the type of acid generator used. ArF excimer laser Far ultraviolet rays represented by (wavelength 193 nm) or KrF excimer laser (wavelength 248 nm) are preferable, and ArF excimer laser (wavelength 193 nm) is particularly preferable.
Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of additive, etc. In the present invention, it is preferable to perform heat treatment (PEB) after exposure. By PEB, the dissociation reaction of the acid dissociable group in the resin component proceeds smoothly. The heating condition of PEB varies depending on the composition of the radiation sensitive resin composition, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  In the present invention, in order to maximize the potential of the radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12252 (Japanese Patent Laid-Open No. 59-93448), etc. An organic or inorganic antireflection film may be formed on the substrate to be formed. Further, in order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the resist film as disclosed in, for example, JP-A-5-188598. Further, in order to prevent the acid generator and the like from flowing out of the resist film in immersion exposure, a liquid immersion protective film is provided on the resist film as disclosed in, for example, JP-A-2005-352384. You can also. These techniques can be used in combination.

  Next, the exposed resist film is developed to form a predetermined resist pattern. Examples of the developer used for this development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propyl. Amine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo -An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. In this case, if the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer, which is not preferable.

Further, for example, an organic solvent can be added to the developer composed of the alkaline aqueous solution. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, and n-propyl. Alcohols such as alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane Esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide. These organic solvents can be used alone or in admixture of two or more. The amount of the organic solvent used is preferably 100% by volume or less with respect to the alkaline aqueous solution. In this case, when the amount of the organic solvent used exceeds 100% by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed area increases. An appropriate amount of a surfactant or the like can be added to the developer composed of the alkaline aqueous solution.
In addition, after developing with the developing solution which consists of alkaline aqueous solution, generally it wash | cleans with water and dries.

  Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Here, the part is based on mass unless otherwise specified.

Each measurement and evaluation in each of the following synthesis examples was performed in the following manner.
(1) Mw and Mn
Gel permeation based on monodisperse polystyrene using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation under the analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. It was measured by an association chromatography (GPC). Further, the degree of dispersion Mw / Mn was calculated from the measurement results.
^{(2) 13} C-NMR analysis of ¹³ C-NMR analysis Each resin using Nippon Denshi Co. "JNM-EX270", was measured.
(3) Amount of low molecular weight component derived from monomer Using an Intersil ODS-25 μm column (4.6 mmφ × 250 mm) manufactured by GL Science, a flow rate of 1.0 ml / min, elution solvent acrylonitrile / 0.1% phosphoric acid aqueous solution Measurement was performed by high performance liquid chromatography (HPLC) under the analysis conditions described above.
In addition, the ratio (mass%) of this component amount is a value with respect to the case where the whole resin is 100 mass%.

Hereinafter, each synthesis example will be described.
Each monomer used for the synthesis of the resin (A) is shown below as formulas (M-1) to (M-6).

Synthesis Example 1 <Synthesis of Resin (A-1)>
Monomer (M-1) 33.57 g (40 mol%), monomer (M-5) 11.99 g (10 mol%) and monomer (M-6) 55.44 g (50 mol%) ) Was dissolved in 200 g of 2-butanone, and a monomer solution containing 4.10 g of dimethylazobisisobutyronitrile was prepared. A 500 ml three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. . After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 1500 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 300 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (80 g, yield 80%). .
As for this polymer, Mw is 6700, Mw / Mn = 1.6, and as a result of ¹³ C-NMR analysis, each repeat derived from monomers (M-1), (M-5), and (M-6) The copolymer had a unit content of 40:10:50 (mol%). This polymer is referred to as “resin (A-1)”. In addition, content of the low molecular weight component derived from each monomer in resin (A-1) was 0.03 mass% with respect to 100 mass% of this polymer.

Synthesis Example 2 <Synthesis of Resin (A-2)>
11.54 g (14 mol%) of the monomer (M-2), 39.21 g (37 mol%) of the monomer (M-4) and 49.25 g (49 mol%) of the monomer (M-6) ) Was dissolved in 200 g of 2-butanone, and a monomer solution charged with 3.98 g of dimethylazobisisobutyronitrile was prepared, and a 500 ml three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. . After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 1500 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 300 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (78 g, yield 78%). .
As for this polymer, Mw is 6400, Mw / Mn = 1.6, ¹³ C-NMR analysis shows that each repeat derived from monomers (M-2), (M-4), and (M-6) The copolymer had a unit content of 14:37:49 (mol%). This polymer is referred to as “resin (A-2)”. In addition, content of the low molecular weight component derived from each monomer in resin (A-2) was 0.03 mass% with respect to 100 mass% of this polymer.

Synthesis Example 3 <Synthesis of Resin (A-3)>
43.08 g (50 mol%) of the monomer (M-1) and 56.92 g (50 mol%) of the monomer (M-6) were dissolved in 200 g of 2-butanone, and further dimethylazobisisobutyro A monomer solution charged with 4.21 g of nitrile was prepared, and a 500 ml three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 1500 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 300 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (83 g, yield 83%). .
This polymer has Mw of 7000, Mw / Mn = 1.5, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the monomers (M-1) and (M-6) is 50: The copolymer was 50 (mol%). This polymer is referred to as “resin (A-3)”. In addition, content of the low molecular-weight component derived from each monomer in resin (A-3) was 0.03 mass% with respect to 100 mass% of this polymer.

Synthesis Example 4 <Synthesis of Resin (A-4)>
11.30 g (15 mol%) of the monomer (M-1), 38.93 g (35 mol%) of the monomer (M-4) and 49.77 g (50 mol%) of the monomer (M-6) ) Was dissolved in 200 g of 2-butanone, and a monomer solution charged with 3.60 g of dimethylazobisisobutyronitrile was prepared, and a 500 ml three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. . After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 1500 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 300 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (81 g, 81% yield). .
This polymer has Mw of 5600, Mw / Mn = 1.6, and as a result of ¹³ C-NMR analysis, each repeating unit derived from monomers (M-1), (M-4) and (M-6) Was a copolymer having a content of 15:35:50 (mol%). This polymer is referred to as “resin (A-4)”. In addition, content of the low molecular-weight component derived from each monomer in resin (A-4) was 0.03 mass% with respect to 100 mass% of this polymer.

<Preparation of radiation-sensitive resin composition>
The resin (A), the acid generator (B), the compound (C), the nitrogen-containing compound (D) and the solvent (E) are mixed at the ratio shown in Table 1, and the radiation-sensitive resin composition in the examples and comparative examples. A product was prepared.

Details of the acid generator (B), the compound (C), the nitrogen-containing compound (D) and the solvent (E) shown in Table 1 are shown below. In the table, “part” is based on mass unless otherwise specified.
<Acid generator (B)>
(B-1): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-tetrafluoro-n-butanesulfonate (B-2): 1- (4- Butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-.tetrafluoro-n-butanesulfonate (B-3): triphenyl Sulfonium-nonafluoro-n-butanesulfonate

<Compound C>
(C-1): A compound having a structure represented by the following formula (1 ′) and having 33% of all R substituted by the following formula (2) (average molecular weight 2115).
(C-2) A compound having a structure represented by the following formula (1 ′) and having 43% of all R substituted by the following formula (2) (average molecular weight 2394).
The average molecular weight of the compound (C) is determined from the ratio of the integral value of the proton of the cyclodextrin skeleton and the proton of the substituent using “JNM-FX200, 500 type (500 MH)” manufactured by JEOL Ltd. as ¹ H-NMR. It calculated from the calculated | required composition.

<Nitrogen-containing compound (D)>
(D-1): Nt-butoxycarbonyl-4-hydroxypiperidine <Solvent (E)>
(E-1): Propylene glycol monomethyl ether acetate (E-2): Cyclohexanone (E-3): Gamma-butyrolactone

<Evaluation of radiation-sensitive resin composition>
Various evaluation was performed as follows about each radiation sensitive resin composition of an Example and a comparative example. These evaluation results are shown in Table 2.

<Sensitivity>
When exposure is performed with an ArF light source, a silicon wafer having an ARC29 (Nissan Chemical Industries Co., Ltd.) film having a film thickness of 770 mm is formed on the wafer surface, and each composition solution is placed on a substrate with a clean track ACT8 (manufactured by Tokyo Electron). ) Using a Nikon ArF excimer laser exposure apparatus “S306C” (opening) on a resist film having a thickness of 0.12 μm formed by spin coating on a hot plate under the conditions shown in Table 2. And exposure through a mask pattern (using a 6% halftone mask). Thereafter, PEB was performed using Clean Track ACT8 (manufactured by Tokyo Electron) under the conditions shown in Table 2, followed by development with an aqueous 2.38% tetramethylammonium hydroxide solution at 25 ° C. for 60 seconds, washing with water, and drying. Thus, a positive resist pattern was formed. At this time, an exposure amount such that a line and space pattern (1L1S) having a diameter of 0.075 μm in the mask becomes a size having a diameter of 0.075 μm was set as the optimum exposure amount, and this optimum exposure amount was set as the sensitivity.

<Resolution>
The dimension (diameter) of the smallest resist pattern that can be resolved at the optimum exposure dose was taken as the resolution.

<EL (exposure margin)>
Using a silicon wafer having an ARC29 (Nissan Chemical Industries Co., Ltd.) film with a film thickness of 770 mm on the wafer surface, each composition solution was applied onto the substrate by spin coating using a clean track ACT8 (manufactured by Tokyo Electron). Using a Nikon ArF excimer laser exposure apparatus “S306C” (numerical aperture 0.78) on a resist film having a film thickness of 0.12 μm formed by performing PB on a hot plate under the conditions shown in Table 2 Exposure was carried out at a predetermined exposure amount through a pattern (using a 6% halftone mask). Thereafter, PEB was performed using Clean Track ACT8 (manufactured by Tokyo Electron) under the conditions shown in Table 2, and then developed with a 2.38% tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds and washed with water. Then, a positive resist pattern [line and space pattern (1L1S, diameter 0.075 μm)] was formed.
At this time, the line pattern size was plotted when the exposure amount was changed in steps of 1.0 mJ / cm ^{2 in} the range of 45 to 65 mJ / cm ² , and the inclination was EL (nm / mJ). .

<Development defects>
The development defect generated in the unexposed area of the positive resist pattern [line and space pattern (1L1S, diameter 0.075 μm)] was observed with an optical microscope for the presence and extent, and further, KLA Tencor Co., Ltd. Evaluation was carried out according to the following procedure using a KLA defect inspection apparatus made by the manufacturer. Evaluation procedure using a KLA defect inspection apparatus: By using a KLA defect inspection apparatus with sensitivity set so that a defect having a size of 0.15 μm or more can be detected, observation is performed in an array mode, and a comparison image and a pixel unit are overlapped. The total number of defects per cluster and uncluster wafers extracted from the resulting differences was measured.

  As is clear from Table 2, the radiation-sensitive resin composition of the present invention, as a chemically amplified resist, has high transparency to radiation and excellent resolution, as well as resistance to dry etching, sensitivity, and pattern shape. Not only is it excellent, it can suppress development defects during microfabrication and can significantly improve the yield of semiconductor elements, and it can be used very suitably in the field of semiconductor elements where further miniaturization is expected in the future. Can do.

Claims (5)

(A) an acid-dissociable group-containing resin having a structure represented by the following formula (3) as a repeating unit having a group that dissociates a protecting group by an acid and expresses alkali solubility of the resin;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation, and (C) a cyclodextrin skeleton and a fluorine atom in the molecular structure, and an average molecular weight calculated from ¹ H NMR is 6000 or less. Compound,
A radiation-sensitive resin composition comprising:

(In Formula (3), R ³ is a hydrogen atom or a methyl group, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ⁵ And R ⁶ are each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or bonded to each other and bonded to each other. And a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms.) The radiation-sensitive resin composition according to claim 1, wherein the compound (C) has 3% by weight or more of fluorine atoms relative to one molecule. (C) compounds, characterized by having a structure represented by the following formula (1), the radiation-sensitive resin composition according to any one of claims 1-2.

(In Formula (1), R ¹ is independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an acyl group having 2 to 20 carbon atoms, an aralkyl group, or an alkenyl group. And at least one of R ¹ is a group represented by the following formula (2), n is 6, 7 or 8.)

(In the formula (2), ^{R 2} is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an acyl group having 2 to 20 carbon atoms, an aralkyl group or an alkenyl group, R ³ Represents a perfluoroalkyl group having 1 to 10 carbon atoms, and * represents a bond.) (C) compounds, characterized in that more than 5% relative to the total R ¹ in Formula (1) is a group table in equation (2), the radiation-sensitive resin composition according to claim 3 . The content of (C) the compound is 0.01% by weight to 20% by weight when the content of (A) the acid dissociable group-containing resin is 100% by weight. The radiation sensitive resin composition of any one of these .