KR20160006113A - Method of forming resist pattern and resist composition - Google Patents

Abstract

The present invention relates to a method for forming a resist pattern including the processes of: forming a resist film by using a resist composition having solubility of a developer changed by acid generated by light exposure on a supporter; exposing light onto the resist film; and forming a resist pattern by developing the resist film. The resist composition contains an acidogenic agent, and the acidogenic agent includes a chemical compound (b1) having a sulfonium cation containing an ether group, and a chemical compound (b2) shown by the formula (b2). [R^21 refers to a ring type functional group capable of having a substitutional group. R^22 refers to F or a fluorinated alkyl group with carbon number C1-C5. Y^21 refers to a divalent connector containing a single bond or 0. V^21 refers to a single-bonded alkylene or fluorinated alkylene group. M′^(m＋) refers to an organic cation with the valence number of m.]

Description

METHOD FOR FORMING RESIST PATTERN AND RESIST COMPOSITION [0002]

The present invention relates to a resist pattern forming method and a resist composition.

In the lithography technique, for example, a resist film made of a resist material is formed on a substrate, and the resist film is subjected to selective exposure with radiation such as light, electron beam or the like through a mask having a predetermined pattern formed thereon, A step of forming a resist pattern of a predetermined shape on the resist film is carried out.

A resist material in which the exposed portion is changed to a property dissolving in the developing solution is referred to as a positive type and a resist material in which the exposed portion is changed into a property not dissolved in the developing solution is referred to as a negative type.

BACKGROUND ART [0002] In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, patterns are being rapidly miniaturized by advances in lithography technology.

As a method of micronization, generally, an exposure light source is shortened (made into a high energy). Specifically, conventionally, ultraviolet rays represented by g-line and i-line have been used, but at present, mass production of semiconductor devices using KrF excimer laser or ArF excimer laser is disclosed. Electron beams of shorter wavelength (higher energy) than those of these excimer lasers, EUV (extreme ultraviolet rays), and X-rays are also being studied.

Resist materials are required to have lithography characteristics such as sensitivity to an exposure light source and resolving ability to reproduce a pattern of fine dimensions.

Various lithography characteristics are affected by standing waves generated by the reflection of light on the surface of the substrate or resist film. Attempts have been made to suppress the influence of light scattered or reflected in various directions by, for example, the shape of the substrate surface such as a stepped substrate or the thickness of the resist film.

For example, Patent Document 1 discloses a method of controlling absorption of light by mixing a dye resin with a photoresist composition to reduce the influence of reflection on the surface of a substrate or a resist film.

Japanese Patent Application Laid-Open No. 10-186647

However, in the method described in Patent Document 1, there is a problem that deterioration of lithography characteristics such as deterioration of resolving power due to introduction of a dye resin occurs. In addition, there was a problem that the dye in the resist film sublimates during the baking treatment at the time of forming the resist film, thereby contaminating the baking plate.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a resist pattern forming method and a resist composition which have good lithography characteristics even when the reflectance of a support is high.

A first aspect of the present invention is a process for producing a resist film, comprising the steps of: forming a resist film on a support by using an acid to generate an acid upon exposure to light and changing the solubility in the developer by the action of an acid; And a step of developing the resist film to form a resist pattern, wherein the resist composition contains an acid generator and the acid generator is a compound having a sulfonium cation that contains an ether group (b1) represented by the following general formula (b1) and a compound (b2) represented by the following general formula (b2).

[Chemical Formula 1]

Wherein R ²¹ is a cyclic group which may have a substituent.

R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.

Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.

V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.

M ' ^{m +} is an organic cation of m.

A second aspect of the present invention is a resist composition which generates an acid by exposure and has a solubility in a developer changed by the action of an acid, wherein the resist composition contains an acid generator and the acid generator, A compound (b1) having a sulfonium cation and a compound (b2) represented by a general formula (b2) shown below.

(2)

Wherein R ²¹ is a cyclic group which may have a substituent.

R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.

Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.

V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.

M ' ^{m +} is an organic cation of m.

In the present specification and claims, the term " aliphatic " is defined as meaning a group, compound, or the like having no aromaticity as a relative concept to an aromatic.

The "alkyl group" is intended to include linear, branched, and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified.

The " alkylene group " includes straight-chain, branched-chain and cyclic divalent saturated hydrocarbon groups, unless otherwise specified. The alkyl group in the alkoxy group is also the same.

The "halogenated alkyl group" is a group in which a part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which a part or all of hydrogen atoms of an alkyl group or an alkylene group are substituted with a fluorine atom.

"Constituent unit" means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).

The term "structural unit derived from an acrylate ester" means a structural unit constituted by cleavage of an ethylenic double bond of an acrylate ester.

"Acrylic acid ester" is a compound in which a hydrogen atom at the carboxyl terminal end of acrylic acid (CH ₂ ═CH-COOH) is substituted with an organic group.

The acrylic acid ester may have a hydrogen atom bonded to the carbon atom at the? -Position thereof substituted with a substituent. The substituent (R ^? ) For substituting a hydrogen atom bonded to the carbon atom at the ^{? -Position} is an atom or a group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, Alkyl groups and the like. The carbon atom at the? -Position of the acrylate ester is a carbon atom to which a carbonyl group is bonded, unless otherwise specified.

Hereinafter, the acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the? -Position is substituted with a substituent is sometimes referred to as? -Substituted acrylate ester. In some cases, an acrylic acid ester and an alpha-substituted acrylic acid ester are collectively referred to as " (alpha-substituted) acrylic ester ".

The term " structural unit derived from vinylbenzoic acid or vinylbenzoic acid derivative " means a structural unit formed by cleavage of the ethylenic double bond of vinylbenzoic acid or vinylbenzoic acid derivative.

The term " vinylbenzoic acid derivative " means a vinylbenzoic acid in which hydrogen atoms at the alpha -position of vinylbenzoic acid are substituted with other substituents such as an alkyl group and a halogenated alkyl group, and derivatives thereof. Examples of the derivatives thereof include those obtained by substituting the hydrogen atom of the carboxyl group of the vinylbenzoic acid in which the hydrogen atom at the α-position may be substituted with an organic group and the benzene ring of vinylbenzoic acid in which the hydrogen atom at the α- A group having a substituent other than the above, and the like. The? Position (carbon atom at?) Refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.

The "styrene derivative" means that the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.

"Constituent unit derived from styrene" and "constituent unit derived from styrene derivative" means a constituent unit in which an ethylene double bond of styrene or a styrene derivative is cleaved.

The alkyl group as the substituent at the? -Position is preferably a linear or branched alkyl group, and more specifically, an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, Butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group).

Specific examples of the halogenated alkyl group as a substituent at the? -Position include a group in which a part or all of the hydrogen atoms of the "alkyl group as a substituent at the? -Position" are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.

Specific examples of the hydroxyalkyl group as the substituent at the? -Position include a group obtained by substituting a part or all of the hydrogen atoms of the "alkyl group as the substituent at the? -Position" with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

Includes the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH ₂ -) with a divalent group when describing "may have a substituent".

&Quot; Exposure " is a concept including the entire irradiation of radiation.

According to the present invention, it is possible to provide a resist pattern forming method and a resist composition having good lithography properties even when the reflectance of the substrate is high.

≪ Method of forming resist pattern &

A first aspect of the present invention is a process for producing a resist film, comprising the steps of: forming a resist film on a support by using an acid to generate an acid upon exposure to light and changing the solubility in the developer by the action of an acid; And a step of developing the resist film to form a resist pattern, wherein the resist composition contains an acid generator and the acid generator is a compound having a sulfonium cation that contains an ether group (b1) represented by the following general formula (b1) and a compound (b2) represented by the following general formula (b2).

(3)

Wherein R ²¹ is a cyclic group which may have a substituent.

R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.

Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.

V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.

M ' ^{m +} is an organic cation of m.

The resist pattern forming method of the present invention includes a step of forming a resist film on a support by using the resist composition of the present invention to be described later, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern do.

The resist pattern forming method of the present invention can be carried out, for example, as follows.

First, a resist composition of the present invention to be described later is applied on a support by a spinner or the like, and the bake (post-apply bake (PAB)) treatment is performed at a temperature of 80 to 150 캜 for 40 to 120 seconds, Is performed for 60 to 90 seconds to form a resist film.

Next, the resist film is exposed or exposed through a mask (mask pattern) having a predetermined pattern formed thereon by using an exposure apparatus such as KrF exposure apparatus, ArF exposure apparatus, electron beam lithography apparatus, EUV exposure apparatus, or the like (Post exposure bake (PEB)) treatment is performed for 40 to 120 seconds at a temperature of, for example, 80 to 150 캜, after performing selective exposure by drawing or the like by direct irradiation of electron beams not having a mask pattern interposed therebetween This is done for 60 to 90 seconds.

Next, the resist film is developed.

The developing treatment is carried out using a developing solution (organic developing solution) containing an alkaline developing solution in the case of the alkali developing process and an organic solvent in the case of the solvent developing process.

After the developing treatment, rinsing treatment is preferably carried out. In the case of the alkali development process, the rinse treatment is preferably performed using pure water, and in the case of the solvent development process, it is preferable to use a rinse solution containing an organic solvent.

In the case of the solvent developing process, a treatment for removing the developing solution or the rinsing liquid adhering to the pattern by the supercritical fluid may be performed after the developing treatment or the rinsing treatment.

After the development treatment or the rinsing treatment, drying is performed. In some cases, a baking process (post-baking) may be performed after the above developing process. In this manner, a resist pattern can be obtained.

In the present invention, the support is not particularly limited, and conventionally known ones can be used. However, when a support having a reflectance of 1.0% or more with respect to light having a wavelength of an exposure light source is used, an excellent effect is exhibited. In the present invention, the term " support " refers to a substrate on which an antireflection film described later is formed on a substrate to be described later.

Conventionally, a method of forming an antireflection film or the like is employed in order to suppress the influence of the standing wave generated by the reflection of light on the surface of a substrate or a resist film.

However, in the case of obtaining a desired pattern, the resist pattern may be formed on a support having a reflectance higher than the reflectance, which is usually lower than 1.0%, even if the amount of the formation material of the antireflection film is smaller than that of the antireflection film, May be desired.

In the present invention, in order to meet such various demands, a good resist pattern having excellent lithography characteristics can be formed even when a support having a reflectance of 1.0% or more with respect to the light of the wavelength of the exposure light source is used.

The reflectance can be calculated by a conventional method by measuring the optical refractive index (n value) and the light absorption rate (k value) when the support is irradiated with light of the exposure wavelength.

For example, when a KrF excimer laser is used as an exposure wavelength, the reflectance is measured by measuring the optical refractive index (n value) and the light absorption rate (k value) when the support is irradiated with light having a wavelength of 248 nm The method may be used.

In the present invention, excellent effects are exhibited when the reflectance of the support is 1.0% or more, more remarkably when the reflectance is 3.0% or more, more remarkably when the reflectance is 5.0% .

As the substrate, for example, there can be mentioned a substrate for an electronic part and a substrate having a predetermined wiring pattern formed thereon. More specifically, examples thereof include substrates made of metal such as silicon wafers, copper, chromium, iron and aluminum, and glass substrates. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold and the like can be used. A variety of stepped substrates can also be used.

Examples of the antireflection film include inorganic and / or organic films. The inorganic film may be an inorganic anti-reflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC) and an organic film such as a lower organic film in the multilayer resist method.

Here, the multi-layer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are formed on a substrate and the resist film formed on the upper resist film is used as a mask Patterning of a lower layer organic film is performed, and a pattern of a Gauss spectrum ratio can be formed. That is, according to the multilayer resist method, since the required thickness can be ensured by the lower organic film, the resist film can be made thinner and a fine pattern of a Gauss spectrum ratio can be formed.

In the multilayer resist method, basically, a method of forming a two-layer structure of an upper layer resist film and a lower layer organic film (two-layer resist method), and forming an intermediate layer (metal thin film or the like) of one or more layers between the upper resist film and the lower organic film (3-layer resist method).

The wavelength to be used for exposure is not particularly limited and may be selected from the group consisting of ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB It can be carried out using radiation. In the present invention, the usefulness as KrF excimer laser, ArF excimer laser, EB or EUV is high, and particularly useful as KrF excimer laser.

The exposure method of the resist film may be a conventional exposure (dry exposure) or an immersion exposure (liquid immersion lithography) in an inert gas such as air or nitrogen.

The liquid immersion exposure is an exposure method in which the resist film and the lens at the lowermost position of the exposure apparatus are previously filled with a solvent (immersion medium) having a refractive index larger than the refractive index of air, and exposure (immersion exposure) is performed in this state.

As the immersion medium, a solvent which is larger than the refractive index of air and has a refractive index smaller than the refractive index of the exposed resist film is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.

Examples of the solvent that is larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicone-based solvent, and a hydrocarbon-based solvent.

Specific examples of the fluorine-based inert liquid include a liquid containing as a main component a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ and C ₅ H ₃ F ₇ , The boiling point is preferably 70 to 180 ° C, and more preferably 80 to 160 ° C. If the fluorine-based inert liquid has a boiling point in the above-mentioned range, it is preferable that the medium used for liquid immersion can be removed by a simple method after the end of exposure.

As the fluorine-based inert liquid, a perfluoroalkyl compound in which the hydrogen atoms of the alkyl group are all substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.

Specific examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C), and the perfluoroalkylamine compound includes perfluorotributyl Amine (boiling point 174 DEG C).

As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility and the like.

Examples of the alkali developing solution used in the developing treatment in the alkali development process include an aqueous solution of 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH).

The organic solvent contained in the organic developing solution used in the developing treatment in the solvent developing process may be any solvent as long as it can dissolve the base component (base component before exposure) of the resist composition and may be appropriately selected from known organic solvents. Specifically, a polar solvent such as a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent or an ether solvent and a hydrocarbon solvent may be used.

If necessary, known additives may be added to the organic developer. As the additive, for example, a surfactant can be mentioned. The surfactant is not particularly limited, and for example, an ionic or nonionic fluorine-based and / or silicone-based surfactant can be used.

When a surfactant is blended, the blending amount thereof is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, more preferably 0.01 to 0.5 mass%, based on the total amount of the organic developer.

The developing treatment can be carried out by a known developing method. For example, there is a method (dip method) of immersing the support in a developing solution for a predetermined time, a method of piling the developing solution on the surface of the support by surface tension, , A method of spraying a developer onto the surface of a support (spray method), a method of continuously extracting a developer while scanning a developer introducing nozzle at a constant speed on a support rotating at a constant speed (dynamic dispensing method), and the like .

The rinsing treatment (rinsing treatment) using the rinsing liquid can be carried out by a known rinsing method. Examples of the method include a method (rotation coating method) of continuously extracting the rinsing liquid on a support rotating at a constant speed, a method (dip method) of immersing the support in a rinsing liquid for a certain period of time, (Spray method), and the like.

Hereinafter, the resist composition used in the resist pattern forming method of the present invention will be described.

The resist composition used in the resist pattern forming method of the present invention is a resist composition which generates an acid by exposure and has a solubility in a developing solution changed by the action of an acid. The resist composition contains an acid generator, , A compound (b1) having an ether group-containing sulfonium cation and a compound (b2) represented by the general formula (b2).

In the present invention, the resist composition contains a resin component (hereinafter sometimes referred to as a "base component" or "(A) component") whose solubility in a developer varies depending on the action of an acid .

When a resist film is formed using such a resist composition and selectively exposed to the resist film, an acid is generated in the exposed portion, and the solubility of the component (A) in the developer is changed by the action of the acid, In the light portion, since the solubility of the component (A) in the developer is not changed, there is a difference in solubility in the developer between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, when the resist composition is a positive type, the exposed portion is dissolved and removed to form a positive resist pattern. When the resist composition is negative, the unexposed portion is dissolved and removed to form a negative A resist pattern is formed.

In the present specification, a resist composition for forming a positive resist pattern by dissolving and removing the exposed portion is referred to as a positive resist composition, and a negative resist composition for forming a negative resist pattern through dissolution and removal of the unexposed portion is referred to as a negative resist composition.

In the present invention, the resist composition may be a positive resist composition or a negative resist composition.

In the present invention, the resist composition may be used for an alkali developing process using an alkali developing solution for developing treatment at the time of forming a resist pattern, and a solvent developing process using an organic solvent (organic developing solution) Process.

In the present invention, the resist composition has acid-generating ability to generate an acid upon exposure, and the acid may be generated by exposure to the component (A) in addition to the acid generator contained in the resist composition.

Specifically, in the present invention, the resist composition may contain,

(1) the acid generator is an acid generator component (B) (hereinafter, referred to as " component (B) ") which generates an acid upon exposure to light, and component (A) ;

(2) The component (A) is a component that generates an acid upon exposure, and may further contain a component (B).

That is, in the case of the above (2), the component (A) becomes a base component which generates an acid by exposure and has a solubility in the developer changed by the action of an acid. (A) is a base component which generates an acid upon exposure to light and the solubility in a developer is changed by the action of an acid, the component (A) described later generates an acid by exposure, And is preferably a polymer compound whose solubility in a developing solution is changed by the action of an acid. As such a polymer compound, a resin having a constituent unit capable of generating an acid upon exposure can be used. As the constituent unit for generating an acid upon exposure, known ones can be used.

In the present invention, the resist composition is particularly preferably the case of the above (1).

≪ Acid Generator Component: Component (B) >

In the present invention, the resist composition comprises an acid generator component (hereinafter referred to as "component (B)") containing a compound (b1) having a sulfonium cation that contains an ether group and a compound (b2) Quot;).

[Chemical Formula 4]

Wherein R ²¹ is a cyclic group which may have a substituent.

R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.

Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.

V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.

M ' ^{m +} is an organic cation of m.

[Compound (b1)]

<Kationbu>

The compound (b1) "hereinafter sometimes simply referred to as" (b1) "is a compound having a sulfonium cation that contains an ether group.

In the present invention, (b1) may be a salt compound having a sulfonium cation that contains an ether group. Examples of the sulfonium cation that contains an ether group include cation represented by the following general formulas (b1-1-1) to (b1-1-3).

[Chemical Formula 5]

Wherein R ¹¹ to R ¹⁵ and R ²⁰ to R ²¹ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ¹¹ to R ¹⁵ , and R ²⁰ to R ²¹ , They may be bonded to each other to form a ring with the sulfur atom in the formula. Provided that at least one of R ¹¹ to R ¹³ , R ¹⁴ to R ¹⁵ and R ²⁰ to R ²¹ contains an ether group.

R ¹⁶ ~ R ¹⁷ each independently represents a hydrogen atom or an alkyl group having a carbon number of 1 ~ 5, R ¹⁹ is an aryl group which may have a substituent, an alkyl group, an alkenyl group, or -SO ₂ - is a group containing a cyclic, L ¹⁸ is -C (= O) - or -C (= O) represents a -O-, Y ³⁰ are, each independently, an aryl group, an alkylene group, or represents an alkenylene group, and x is 1 or 2, W is ³⁰ (x + 1).

As the aryl group in R ¹¹ to R ¹⁵ and R ²⁰ to R ²¹ , an unsubstituted aryl group having 6 to 20 carbon atoms can be mentioned, and a phenyl group or a naphthyl group is preferable.

The alkyl group in R ¹¹ to R ¹⁵ and R ²⁰ to R ²¹ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group in R ¹¹ to R ¹⁵ and R ²⁰ to R ²¹ preferably has 2 to 10 carbon atoms.

R ¹¹ ~ R ^15, and R ²⁰ ~ R substituent which may ²¹ have, R ¹¹ ~ R ^15, and R ²⁰ ~ R ^21, at least one of which, if it contains an ether group and, except for those, for example, A group represented by each of the following formulas (ca-r-1) to (ca-r-7) includes an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group,

The aryl group in the arylthio group as a substituent is the same as those exemplified for R ¹¹ , and specifically includes a phenylthio group or a biphenylthio group.

[Chemical Formula 6]

Wherein each R ' ²⁰¹ independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain-like alkyl group or a chain-like alkenyl group.

The cyclic group which may have a substituent of R ' ^{201 includes} the same groups as R ²¹ in the formula (b2) described later, and may be a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent Group may be the same as R ¹¹ in the above formula (b1-1-1), or may be a cyclic group which may have a substituent or a chain alkyl group which may have a substituent, 2). &Lt; / RTI &gt;

When R ¹¹ to R ¹⁵ and R ²⁰ to R ²¹ are bonded to each other to form a ring together with the sulfur atom in the formula, they may be heteroatoms such as a sulfur atom, an oxygen atom and a nitrogen atom, a carbonyl group, -SO-, SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N (R _N ) - (R _N is an alkyl group having 1 to 5 carbon atoms). As the ring to be formed, one ring containing the sulfur atom in the formula in the ring structure is preferably a ring of 3 to 10 atoms, inclusive of a sulfur atom, and particularly preferably a ring of 5 to 7 atoms. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, A thianthrene ring, a phenoxathiine ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring and the like.

Each of R ¹⁶ to R ¹⁷ independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When the alkyl group is an alkyl group, they may be bonded to each other to form a ring.

R ¹⁹ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO ₂ -containing cyclic group which may have a substituent.

As the aryl group in R ¹⁹ , an unsubstituted aryl group having 6 to 20 carbon atoms can be mentioned, and a phenyl group or a naphthyl group is preferable.

The alkyl group in R ¹⁹ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group in R ¹⁹ preferably has 2 to 10 carbon atoms.

Examples of the -SO ₂ -containing cyclic group which may have a substituent in R ¹⁹ include the same ones as the "-SO ₂ -containing cyclic group" of Ra ²¹ in the general formula (a2-1) described later , And a group represented by the general formula (a5-r-1) described later is preferable.

Y ³⁰ each independently represent an arylene group, an alkylene group or an alkenylene group.

The arylene group for Y ³⁰ includes a group obtained by removing one hydrogen atom from an aryl group exemplified as an aromatic hydrocarbon group in R ²¹ in the formula (b2) to be described later.

The alkylene group and alkenylene group in Y ³⁰ may be the same as the aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ in the general formula (a1-1) to be described later.

In the formula (b1-1-3), x is 1 or 2.

W ³⁰ is (x + 1), that is, a divalent or trivalent linking group.

As the divalent linking group in W ³⁰ , a divalent hydrocarbon group which may have a substituent is preferable, and the same hydrocarbon group as Ya ²¹ in the general formula (a2-1) described later can be exemplified. The bivalent linking group in W ³⁰ may be any of linear, branched, and cyclic, preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.

Examples of the trivalent linking group in the ³⁰ W, is in a divalent connecting group in the ³⁰ W additionally a hydrogen atom in the group, the divalent connecting group 1 removed, and the like groups bonded groups are the divalent connection. As the trivalent linking group in W ³⁰ , a group in which two carbonyl groups are bonded to an arylene group is preferable.

In the present invention, the cation unit of (b1) is preferably a cation unit represented by the general formula (b1-1-1).

The cation represented by the general formula (b1-1-1) is preferably a general formula (b1-1-1-1) or (b1-1-1-2) shown below.

(7)

Wherein R ⁴⁰¹ is a hydrocarbon group which may have a substituent, and R ⁴⁰² to R ⁴⁰⁴ are each a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, n ^b1 is an integer of 0 to 5, provided that at least one n ^b1 is 1. n ^b2 to n ^b4 are integers greater than or equal to zero.]

In the general formula (b1-1-1-1) or (b1-1-1-2), R ⁴⁰¹ represents a hydrocarbon group which may have a substituent, R ⁴⁰² to R ^{404 each} represent a hydrogen atom, an alkyl group, a halogen atom, A halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group or an arylthio group. n ^b1 is an integer of 0 to 5, provided that at least one n ^b1 is 1. n ^b2 to n ^b4 are an integer of 0 or more.

In the general formula (b1-1-1-1) or (b1-1-1-2), the hydrocarbon group which may have a substituent represented by R ⁴⁰¹ is preferably an alkyl group, and a linear or branched alkyl group , And more preferably a linear alkyl group. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 6 carbon atoms.

As R ⁴⁰¹ , for example, -CH ₂ -C (═O) -OR ⁵⁰¹ (R ⁵⁰¹ is a linear or branched alkyl group which may have a substituent or a cyclic group which may have a substituent .).

The linear or branched alkyl group for R &lt; ⁵⁰¹ &gt; includes the same groups as the linear or branched alkyl group described above for R &lt; ⁴⁰¹ &gt;.

The cyclic group in R ⁵⁰¹ includes a group obtained by removing one hydrogen atom from a monocycloalkane or polycycloalkane exemplified as a bivalent aliphatic hydrocarbon group in Va ¹ of the general formula (a1-1) to be described later, An adamantyl group, and a norbornyl group are preferable.

Also, R ⁴⁰¹ may be -CH ₂ -OR ⁵⁰² (R ⁵⁰² is a cyclic group). Examples of the cyclic group represented by R ⁵⁰² include an adamantyl group and a norbornyl group.

In the general formula (b1-1-1-1) or (b1-1-1-2), R ⁴⁰² to R ⁴⁰⁴ are preferably an alkyl group, preferably a linear alkyl group, and the number of carbon atoms Is preferably 1 to 10, more preferably 1 to 5.

In the general formula (b1-1-1-1) or (b1-1-1-2), n ^b1 to n ^b2 are preferably 1 to 2, and n ^b3 to n ^b4 are preferably 0.

In the general formula (b1-1-1-1) or (b1-1-1-2), and a plurality of R ⁴⁰¹ are be the same or different, n ^b1 is an integer from 0 to 5, the plurality of n ^b1 , At least one n ^b1 is 1.

Specific examples of the preferred cation represented by the general formula (b1-1-1) include cation represented by any of the following.

[Chemical Formula 8]

[Chemical Formula 9]

[Chemical formula 10]

G1 represents an integer of 1 to 5, g2 represents an integer of 0 to 20, and g3 represents an integer of 0 to 20.] [wherein, g1, g2 and g3 represent repeating numbers,

(11)

Wherein R &quot; ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as those exemplified as the substituent that R ¹¹ to R ¹⁵ and R ²⁰ to R ²¹ may have.]

[Compound (b1)]

<The Onion>

The anion moiety of (b1) is not particularly limited, and for example, an anion moiety represented by the following general formula (b-1) is preferable.

[Chemical Formula 12]

: Wherein R ¹⁰¹ is a chained alkyl group which may have a substituent or a chain-like alkenyl group which may have a substituent; R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group.]

In the formula (b-1), R ¹⁰¹ is a chain-like alkyl group which may have a substituent or a chain-like alkenyl group which may have a substituent.

(A chain alkyl group which may have a substituent in R &lt; ¹⁰¹ &gt;),

The chain alkyl group of R &lt; ¹⁰¹ &gt; may be either linear or branched.

The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, , A tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, a heneicosyl group and a docosyl group.

The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples thereof include 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, -Ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

(A chain type alkenyl group which may have a substituent in R ¹⁰¹ )

The chain type alkenyl group of R &lt; ¹⁰¹ &gt; may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, and most preferably 3 Is particularly preferable. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butyryl group. Examples of the branched-chain alkenyl group include a 1-methylpropenyl group and a 2-methylpropenyl group.

As the chain-like alkenyl group, the above-mentioned propenyl group is particularly preferable.

Examples of the substituent in the chain type alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, a group represented by R ²¹ in the formula (b2) A cyclic group and the like.

In the formula (b-1), Y ¹⁰¹ is a divalent linking group containing a single bond or an oxygen atom.

If the Y ¹⁰¹ 2-valent connecting group containing an oxygen atom, and Y is ^101, it may contain an atom other than an oxygen atom. Examples of the atoms other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: -O-), an ester bond (-C (= O) -O-), an oxycarbonyl group (-OC , A non-hydrocarbon-based oxygen atom-containing linking group such as an amide bond (-C (= O) -NH-), a carbonyl group (-C (= O) -) and a carbonate bond (-OC (= O) -O-); And combinations of the non-hydrocarbon-based oxygen atom-containing linking group and the alkylene group. The combination may further include a sulfonyl group (-SO ₂ -). Examples of the combination include a linking group represented by the following formulas (y-al-1) to (y-al-7).

[Chemical Formula 13]

Wherein V ' ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

The divalent saturated hydrocarbon group in V ' ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group in V ' ¹⁰¹ and V' ¹⁰² may be a linear alkylene group, a branched chain alkylene group, or a linear alkylene group.

V as an alkylene group in the ^"101 and V" ¹⁰² Specifically, a methylene group _{[-CH 2 -]; -CH (} CH 3) -, -CH (CH 2 CH 3) -, -C (CH 3) _{2 -, -C (CH 3)} (CH 2 CH 3) -, -C (CH 3) (CH 2 CH 2 CH 3) -, -C (CH 2 CH 3) 2 - a methylene group of the alkyl and the like; ethylene group _{[-CH 2 CH 2 -];} -CH (CH 3) CH 2 -, -CH (CH 3) CH (CH 3) -, -C (CH 3) 2 CH 2 -, -CH (CH 2 CH ₃₎ CH ₂ - alkyl group such as ethylene; trimethylene group (n- propylene _{group) [- CH 2 CH 2 CH} 2 -]; -CH (CH 3) CH 2 CH 2 -, -CH 2 CH (CH 3 ) CH ₂ -, tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -], -CH (CH ₃ ) CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ CH ₂ -, etc .; pentamethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -] and the like.

In addition, some of the methylene groups in the alkylene group in V ' ¹⁰¹ or V' ¹⁰² may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra ' ³ in the formula (a1-r-1) to be described later, and a cyclohexylene group, -Adamantylene group or a 2,6-adamantylene group is more preferable.

As Y ¹⁰¹ , a divalent linking group including an ester bond or an ether bond is preferable, and a linking group represented by the above formulas (y-al-1) to (y-al-5) is preferable.

In the formula (b-1), V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V ¹⁰¹ preferably have 1 to 4 carbon atoms. As the fluorinated alkyl group of the ¹⁰¹ V, a part or all of the hydrogen atoms of the alkylene group of the ¹⁰¹ V it may be substituted with a fluorine atom. Among them, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In the formula (b-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

As specific examples of the anion of the compound (b1), for example, when Y ¹⁰¹ is a single bond, a fluorinated alkylsulfonate anion such as trifluoromethanesulfonate anion or perfluorobutanesulfonate anion And when Y ¹⁰¹ is a divalent linking group containing an oxygen atom, an anion represented by any of the following formulas (an-1) and (an-3) may be mentioned.

[Chemical Formula 14]

[Wherein, R ^"101 is an alkyl group of chain which may have a substituent; R" ¹⁰³ is an alkenyl group of chain which may have a substituent; V ^"101 is a fluorinated alkyl group and; L" ¹⁰¹ is, -C (= O) - or -SO ₂ -, and; v "are each independently an integer of 0 ~ 3, q" is an integer from 1 to 20, each independently, n "is 0 or 1. ]

The chain alkyl group which may have a substituent in R &quot; ¹⁰¹ is preferably a group exemplified as the chain alkyl group in R &lt; ^{101 &} gt ;. The chain type alkenyl group which may have a substituent in R &quot; ¹⁰³ is preferably a group exemplified as a chain type alkenyl group in R &lt; ^{101 &} gt ;. V " ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, particularly preferably -CF ₂ -, -CF ₂ CF ₂ -, -CHFCF ₂ -, -CF (CF ₃ ) CF ₂ - -CH (CF ₃₎ CF ₂ - a.

In the present invention, the anion moiety and cation moiety of the compound (b1) may be arbitrarily combined with each other as described above.

In the present invention, it is preferable that the compound (b1) is a compound represented by the following general formula (b1-1).

[Chemical Formula 15]

[Wherein R ¹¹ to R ¹³ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. Provided that at least one of R ¹¹ to R ¹³ contains an ether group. R ¹¹ to R ¹³ may bond to each other to form a ring with the sulfur atom in the formula.

And R &lt; ^{41 &gt;} is a chain-like fluorinated alkyl group.

In the general formula (b1-1), R ¹¹ to R ¹³ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ¹¹ to R ¹³ are as described above. R ⁴¹ is a chain-like fluorinated alkyl group, preferably a fluorinated alkyl group having 1 to 10 carbon atoms, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms.

[Compound (b2)]

In the present invention, the acid generator contained in the resist composition contains the compound (b2) represented by the following general formula (b2).

[Chemical Formula 16]

Wherein R ²¹ is a cyclic group which may have a substituent.

R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.

Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.

V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.

M ' ^{m +} is an organic cation of m.

[Compound (b2)]

<The Onion>

In the general formula (b2), R ²¹ is a cyclic group which may have a substituent.

(A cyclic group which may have a substituent in R ²¹ )

The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

The aromatic hydrocarbon group for R ²¹ is preferably an aromatic hydrocarbon ring exemplified as a bivalent aromatic hydrocarbon group in Va ¹ of the general formula (a1-1) to be described later, or an aromatic hydrocarbon ring containing two or more aromatic rings, , And phenyl group and naphthyl group are preferable.

The cyclic aliphatic hydrocarbon group for R ²¹ is a monocycloalkane or polycycloalkane exemplified by a bivalent aliphatic hydrocarbon group represented by Va ¹ in the general formula (a1-1) to be described later, in which one hydrogen atom is removed, And an adamantyl group and a norbornyl group are preferable.

The cyclic hydrocarbon group for R ²¹ may include a hetero atom such as a heterocyclic ring and specifically includes a lactone group represented by the following formulas (a2-r-1) to (a2-r-7) containing cyclic group, each representing by the formula (a5-r-1) ~ (a5-r-4) to be described later -SO ₂ - containing cyclic groups, other than (r-hr-1) ~ (r- hr-16).

[Chemical Formula 17]

Examples of the substituent in the cyclic hydrocarbon group of R ²¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and a nitro group.

The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, , Ethoxy group is most preferable.

Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms such as groups in which some or all of hydrogen atoms such as methyl, ethyl, propyl, n-butyl and tert-butyl groups are substituted with the above halogen atoms .

It is more preferable that R ²¹ is a cyclic hydrocarbon group which may have a substituent. More specifically, a lactone-containing cyclic group represented by the general formula (a2-r-1) to (a2-r-7), respectively, which is obtained by removing at least one hydrogen atom from a phenyl group, a naphthyl group or a polycycloalkane, , And -SO ₂ -containing cyclic groups represented by the following general formulas (a5-r-1) to (a5-r-4).

In the general formula (b2), Y ²¹ is a divalent linking group containing a single bond or an oxygen atom. The description of Y ²¹ is the same as the description of the single bond or the divalent linking group containing an oxygen atom in Y ¹⁰¹ in the above formula (b-1).

In the general formula (b2), ²¹ V is a single bond, an alkylene group, or a fluorinated alkyl group.

The description of V ²¹ is the same as the description of V ¹⁰¹ in the above general formula (b-1).

In the general formula (b2), R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ²² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

As specific examples of the anion portion of the component (b2), for example, when Y ²¹ is a single bond, a fluorinated alkylsulfonate anion such as trifluoromethanesulfonate anion or perfluorobutanesulfonate anion And an anion represented by any one of the following formulas (an-1) to (an-3) when Y ²¹ is a divalent linking group containing an oxygen atom.

[Chemical Formula 18]

[Wherein, R ^"101 is an aliphatic cyclic group which may have a substituent, each represented by the above formula (r-hr-1) ~ (r-hr-6); R" 102 is may have a substituent (A5-r-1) to (a5-r-1), which are represented by the following general formulas (a2- r-4) each represent a -SO ₂ - containing cyclic group and; R ^"103 is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent; V" ¹⁰¹ is a fluorinated alkyl L " ¹⁰¹ is -C (═O) - or -SO ₂ -; v" is independently an integer of 0 to 3; q "is independently an integer of 1 to 20; n" Is 0 or 1.]

The aliphatic cyclic group which may have a substituent group of R " ¹⁰¹ , R" ¹⁰² and R " ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in R ²¹ . The substituent may be the same as the substituent which may be substituted for the cyclic aliphatic hydrocarbon group in R &lt; ²¹ &gt;.

The aromatic cyclic group which may have a substituent in R &quot; ¹⁰³ is preferably a group exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group for R &lt; ^{21 &} gt ;. The substituent may be the same as the substituent which may be substituted with the aromatic hydrocarbon group in R ²¹ .

Specific examples of the anion moiety of the compound (b2) are shown below.

[Chemical Formula 19]

[Compound (b2)]

<Kationbu>

In the formula (b2), M ' ^{m +} is preferably an organic cation of m valence, and among them, sulfonium cation or iodonium cation is preferable, and the following general formulas (ca-1) to Particularly preferred are the cations represented respectively.

[Chemical Formula 20]

^Wherein R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ²¹¹ To R &lt; ²¹² &gt; may bond together to form a ring with the sulfur atom in the formula. R ²⁰⁸ ~ R ²⁰⁹ each independently represents a hydrogen atom or an alkyl group having a carbon number of 1 ~ 5, R ²¹⁰ is an aryl group which may have a substituent, an alkyl group, an alkenyl group, or -SO ₂ - and containing cyclic group, L ²⁰¹ is -C (= O) - or -C (= O) represents a -O-, Y ²⁰¹ each independently, an aryl group, an alkylene group or alkenylene group, and x is 1 or 2, W is ²⁰¹ (x + 1).

As the aryl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² , an unsubstituted aryl group having 6 to 20 carbon atoms can be mentioned, and a phenyl group or a naphthyl group is preferable.

The alkyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² preferably has 2 to 10 carbon atoms.

Examples of the substituent that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, r-1) to (ca-r-7).

The aryl group in the arylthio group as a substituent is the same as those exemplified for R ²¹ , and specifically includes a phenylthio group or a biphenylthio group.

[Chemical Formula 21]

Wherein each R ' ²⁰¹ independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain-like alkyl group or a chain-like alkenyl group.

The cyclic group which may have a substituent of R ' ²⁰¹ , the chain alkyl group which may have a substituent, or the chain-like alkenyl group which may have a substituent may be represented by R ¹⁰¹ in the above formula (b-1) in addition to b2) being in the same groups as in R ^21, an acid dissociable group represented by formula (a1-r-2) to be described later as an alkyl chain which may have a cyclic group or a substituent which may have a substituent the same Also,

When R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ²¹¹ to R ²¹² are bonded to each other to form a ring together with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom or a nitrogen atom, -SO-, -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N (R _N ) - (R _N is an alkyl group having 1 to 5 carbon atoms) You can. As the ring to be formed, one ring containing the sulfur atom in the formula in the ring structure is preferably a ring of 3 to 10 atoms, inclusive of a sulfur atom, and particularly preferably a ring of 5 to 7 atoms. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, A thianthrene ring, a phenoxathiine ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring and the like.

Each of R ²⁰⁸ to R ²⁰⁹ independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When the alkyl group is an alkyl group, they may be bonded to each other to form a ring.

R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO ₂ -containing cyclic group which may have a substituent.

As the aryl group in R ²¹⁰ , an unsubstituted aryl group having 6 to 20 carbon atoms can be mentioned, and a phenyl group and a naphthyl group are preferable.

The alkyl group in R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group in R ²¹⁰ preferably has 2 to 10 carbon atoms.

The -SO ₂ -containing cyclic group which may have a substituent in R ²¹⁰ is the same as the "-SO ₂ -containing cyclic group" of Ra ²¹ in the general formula (a2-1) described later , And a group represented by the following general formula (a5-r-1) is preferable.

Y ²⁰¹ each independently represent an arylene group, an alkylene group or an alkenylene group.

The arylene group for Y ²⁰¹ includes a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group for R ²¹ in the formula (b2).

The alkylene group and alkenylene group in Y ²⁰¹ may be the same as the aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ in the general formula (a1-1) to be described later.

In the above formula (ca-4), x is 1 or 2.

W ²⁰¹ is (x + 1), that is, a divalent or trivalent linking group.

As the divalent linking group in W ²⁰¹ , a divalent hydrocarbon group which may have a substituent is preferable, and the same hydrocarbon group as Ya ²¹ in the general formula (a2-1) described later can be exemplified. The bivalent linking group in W ²⁰¹ may be any of linear, branched, and cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.

Examples of the trivalent linking group in W ^201, is in a divalent connecting group in the above ²⁰¹ W of additional hydrogen atoms in the group, the divalent connecting group 1 removed, and the like groups bonded groups are the divalent connection. As the trivalent linking group in W ²⁰¹ , a group in which two carbonyl groups are bonded to an arylene group is preferable.

Specific examples of preferred cation represented by the formula (ca-1) include cation represented by the following formulas (ca-1-1) to (ca-1-63).

[Chemical Formula 22]

(23)

&Lt; EMI ID =

G1 represents an integer of 1 to 5, g2 represents an integer of 0 to 20, and g3 represents an integer of 0 to 20.] [wherein, g1, g2 and g3 represent repeating numbers,

(25)

Wherein R ²⁰¹ is a hydrogen atom or a substituent and the substituent is the same as those exemplified as the substituent which R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have.

Specific examples of preferred cation represented by the above formula (ca-3) include cation represented by the following formulas (ca-3-1) to (ca-3-6).

(26)

Specific examples of preferred cation represented by the above formula (ca-4) include cation represented by the following formulas (ca-4-1) to (ca-4-2).

(27)

[Compound (b3)]

In the present invention, the component (B) preferably contains a compound (b3) having a diazomethylene disulfonyl skeleton. Examples of the compound (b3) include diazomethylene disulfonyldicyclohexane.

In the component (B), the compounding ratio of the compound (b1) to the compound (b2) is preferably 1.0 to 2.0 parts by mass, more preferably 1.2 to 1.7 parts by mass, relative to 1 part by mass of the compound (b1) More preferably from 1.2 to 1.5 parts by mass.

By setting the blending ratio, the resist pattern shape can be made good.

In the resist composition of the present invention, the content of the component (B) is preferably from 0.5 to 60 parts by mass, more preferably from 1 to 50 parts by mass, further preferably from 1 to 40 parts by mass, per 100 parts by mass of the component (A) . By setting the content of the component (B) within the above range, sufficient pattern formation can be achieved. Further, when each component of the resist composition is dissolved in an organic solvent, a homogeneous solution can be obtained and storage stability is improved, which is preferable.

&Lt; Resin component: (A) component &gt;

In the present invention, it is preferable that the resist composition contains at least one resin selected from the group consisting of a novolak resin, a polyhydroxystyrene resin, and an acrylic resin.

[Novolac resin]

The novolak resin is not particularly limited and may be selected arbitrarily from among those conventionally proposed for use in a resist composition, and preferably, an aromatic hydroxy compound and an aldehyde and / or a ketone are condensed And a novolak resin obtained by reacting the above-mentioned novolac resin.

Examples of the aromatic hydroxy compound used in the synthesis of the novolak resin include phenols such as phenols, cresols such as m-cresol, p-cresol, o-cresol and the like; Methylphenol, o-ethylphenol, 2,3,5-trimethylphenol, 2,3, 5-trimethylphenol, Butylphenol, 2-tert-butylphenol, 2-tert-butylphenol-4-methylphenol and 2-tert-butylphenol Alkoxyphenols such as p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol and m-propoxyphenol, o- isopropenylphenol, 2-methyl-4-isopropenylphenol, 2-ethyl-4-isopropenylphenol and the like, arylphenols such as phenylphenol and the like, 4,4'- Polybasic acids such as bisphenol A, resorcinol, hydroquinone, pyrogallol, etc. There may be mentioned a hydroxy-phenol, etc. These may be used alone or in combination of two or more.

Examples of the aldehydes used in the synthesis of novolac resins include aldehydes such as formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, butylaldehyde, trimethylacetaldehyde, acrolein, crotonaldehyde, cyclohexanaldehyde, furfural, Methylbenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, o-hydroxybenzaldehyde, p-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, Benzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde and cinnamic acid aldehyde. These may be used alone or in combination of two or more.

Among these aldehydes, it is preferable to use formaldehyde for easy access. Particularly, in view of good heat resistance, it is preferable to use formaldehyde in combination with hydroxybenzaldehyde such as o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, and p-hydroxybenzaldehyde.

The ketones used for the synthesis of the novolak resin include, for example, acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone and the like. These may be used alone or in combination of two or more.

Furthermore, the above-mentioned aldehydes and ketones may be suitably used in combination. The novolac resin can be produced by condensation reaction of the aromatic hydroxy compound and aldehydes and / or ketones in the presence of an acidic catalyst by a known method. As the acid catalyst at this time, hydrochloric acid, sulfuric acid, formic acid, oxalic acid, paratoluenesulfonic acid, and the like can be used.

The Mw of the component (A) before being protected by the acid dissociable, dissolution inhibiting group is preferably in the range of 2,000 to 50,000, and the weight average molecular weight (Mw) of the novolak resin (converted to polystyrene by gel permeation chromatography (GPC) More preferably from 3,000 to 20,000, and still more preferably from 4,000 to 15,000. When the Mw is 2000 or more, the negative resist composition is dissolved in an organic solvent and coated on the substrate, and when it is 50000 or less, the resolution is good.

In the present invention, it is preferable that the novolac resin is subjected to treatment for fractionating and removing low molecular weight substances. As a result, the heat resistance is further improved.

Examples of the low-molecular weight compound used in the present invention include, among the monomers such as aromatic hydroxy compounds, aldehydes and ketones used for the synthesis of the novolak resin, residual monomers remaining unreacted, dimer , Tri-molecular-bonded trimers (such as monomers and 2 to 3 nuclei).

The fractionation treatment method of the low molecular weight substance is not particularly limited and includes, for example, a method of refining using an ion exchange resin, a method of separating the low molecular weight substance by a known separating operation using a poor solvent (alcohol etc.) Can be used. According to the former method, it is possible to remove an acid component or a metal component together with a low molecular weight component.

The yield in the fractional removal treatment of such a low molecular weight compound is preferably in the range of 50 to 95 mass%.

If it is 50 mass% or more, the difference in dissolution rate between the exposed portion and the unexposed portion increases, and the resolution is good. On the other hand, if it is 95 mass% or less, the effect of performing fractional removal can be sufficiently obtained.

The content of the low molecular weight compound having Mw of 500 or less is preferably 15% or less, preferably 12% or less, on the GPC chart. When it is 15% or less, the effect of improving the heat resistance of the resist pattern is exhibited, and the effect of suppressing the amount of the sublimate generated during the heat treatment is exhibited.

[Polyhydroxy styrene resin]

As the polyhydroxystyrene resin, a resin having a constituent unit derived from hydroxystyrene (hereinafter sometimes referred to as a polyhydroxystyrene (PHS) resin) is also preferably used. By using such a resin, a high-resolution pattern can be formed.

In addition, since the microfabrication can be performed even in the case of a thick film, it is possible to form a pattern with a high aspect ratio, and as a result, resistance to dry etching is improved.

Here, the term "hydroxystyrene" refers to hydroxystyrene and hydrostyrene in which the hydrogen atom bonded to the carbon atom at the α-position of the hydroxystyrene is substituted with another substituent such as a halogen atom, an alkyl group, a halogenated alkyl group, A benzene ring in which a substituent as described above is bonded to the benzene ring, etc.). The number of hydroxyl groups bonded to the benzene ring of hydroxystyrene is preferably an integer of 1 to 3, more preferably 1. The? -Position (carbon atom at? -Position) of hydroxystyrene is a carbon atom to which a benzene ring is bonded, unless otherwise specified.

The term "structural unit derived from hydroxystyrene" means a structural unit composed of an ethylene double bond of hydroxystyrene formed by cleavage.

The proportion of the constitutional unit derived from hydroxystyrene in the PHS resin is preferably 50 to 100 mol%, more preferably 80 to 100 mol% with respect to the total of all the constituent units constituting the PHS resin . Specific examples of the PHS-based resin include polyhydroxystyrene, hydroxystyrene-styrene copolymer, and the like.

Examples of the hydroxystyrene-styrene copolymer include a copolymer having a constituent unit (ps1) represented by the following general formula (I) and a constituent unit (ps2) represented by the following general formula (II)

(28)

(Wherein R ^st represents a hydrogen atom or a methyl group, and m ₀₁ represents an integer of 1 to 3)

[Chemical Formula 29]

(Wherein R ^st represents a hydrogen atom or a methyl group, R ⁰¹ represents an alkyl group having 1 to 5 carbon atoms, and m ₀₂ represents 0 or an integer of 1 to 3.)

In the structural unit (ps1) represented by the general formula (I), R ^st is preferably a hydrogen atom or a methyl group, and is preferably a hydrogen atom.

m ₀₁ is an integer of 1 to 3; Of these, m ₀₁ is preferably 1.

The position of the hydroxyl group may be any of o-position, m-position and p-position, but it is preferable that m is 1 and also has a hydroxyl group at the p-position in view of availability and low cost. When m ₀₁ is 2 or 3, arbitrary substitution positions can be combined.

In the structural unit (ps2) represented by the general formula (II), R ^st is preferably a hydrogen atom or a methyl group, and is preferably a hydrogen atom.

R ⁰¹ is a linear or branched alkyl group having 1 to 5 carbon atoms and is preferably a linear or branched alkyl group having 1 to 5 carbon atoms which may have a substituent such as a methyl group, an ethyl group, Neopentyl group and the like. Industrially, a methyl group or an ethyl group is preferable.

M ₀₂ is 0 or an integer of 1 to 3; Of these, m ₀₂ is preferably 0 or 1, and particularly preferably 0 for industrial use.

When m ₀₂ is 1, the substitution position of R 1 may be any of o-, m-, and p-, and when m ₀₂ is 2 or 3, arbitrary substitution positions may be combined can do.

As the PHS-based resin, 3 to 40 mol% of the hydrogen atoms of the hydroxyl groups of the polyhydroxystyrene may be replaced with alkali-insoluble groups, thereby reducing the alkali solubility.

It is preferable that 5 to 30 mol% of the hydrogen atoms of the hydroxyl groups of the constituent unit (ps1) in the copolymer having the constituent unit (ps1) and the constituent unit (ps2) are substituted with an alkali insoluble group, A material having reduced solubility may be used.

Here, the "alkali insoluble group" is a substituent which lowers the alkali solubility of the unsubstituted alkali-soluble resin and includes, for example, tertiary alkoxycarbonyl groups such as tert-butoxycarbonyl group and tert-amyloxycarbonyl group, , a n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.

The mass average molecular weight of the PHS resin is preferably 1000 to 10000, and more preferably 2000 to 4000 when KrF excimer laser and / or electron beam are used for the mix-and-match.

[Acrylic resin]

As the acrylic resin, a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid, a structural unit containing a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ -containing cyclic group ( (a2) (excluding those corresponding to the above-mentioned structural units (a1)), structural units (a3) containing a polar group-containing aliphatic hydrocarbon group , A structural unit (a4) containing an acid-dissociable cyclic group, and the like.

As the structural unit (a1), resins containing the structural units represented by the following general formulas (a1-1) to (a1-2) may be used.

(30)

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond, a urethane bond or an amide bond, n _a1 are each independently 0 to 2, Ra ¹ is a group represented by the following formulas (a1-r-1) to -2). &Lt; / RTI &gt; Wa ¹ is a monovalent hydrocarbon group, n _a2 +1, n _a2 is 1 ~ 3, Ra ² is an acid dissociable group represented by the following formula (a1-r-1) or (a1-r-3). ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched chain, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n- A tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable because of industrial availability.

The divalent hydrocarbon group of Va &lt; ¹ &gt; may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is preferably saturated.

More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in the structure.

As Va ¹ , the above-mentioned divalent hydrocarbon group may be bonded via an ether bond, a urethane bond or an amide bond.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH ₂ -], an ethylene group [- (CH ₂ ) ₂ -], a trimethylene group [- CH ₂ ) ₃ -], tetramethylene group [- (CH ₂ ) ₄ -], pentamethylene group [- (CH ₂ ) ₅ -] and the like.

As the aliphatic hydrocarbon group branched, with preferably an alkylene group of branched, and _{specifically, -CH (CH 3) -,} -CH (CH 2 CH 3) -, -C (CH 3) 2 -, _{-C (CH 3) (CH 2} CH 3) -, -C (CH 3) (CH 2 CH 2 CH 3) -, -C (CH 2 CH 3) 2 - a methylene group, such as alkyl; -CH (CH _{3) CH 2 -, -CH (} CH 3) CH (CH 3) -, -C (CH 3) 2 CH 2 -, -CH (CH 2 CH 3) CH 2 -, -C (CH 2 CH 3) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH (CH ₃ ) CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ -, and the like; -CH (CH ₃ ) CH ₂ CH _And alkyltetramethylene groups such as ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ CH ₂ -, and the like. As the alkyl group in the alkyl alkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Examples of the aliphatic hydrocarbon group having a ring in the structure include alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), alicyclic hydrocarbon groups in which alicyclic hydrocarbon groups are bonded to the ends of a linear or branched aliphatic hydrocarbon group And a group in which an alicyclic hydrocarbon group is introduced in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same ones as described above.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, and the like. The polycyclic alkyd hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from the polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples thereof include adamantane, norbornane, isobor Trichlorosilane, tetrachlorododecane, tetracyclododecane, and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.

The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, 6 to 10 is most preferable. Provided that the number of carbon atoms does not include the number of carbon atoms in the substituent.

Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene and phenanthrene; aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom ; And the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group), one of the hydrogen atoms of the group (aryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring is an alkylene group A hydrogen atom in the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, A group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.), and the like. The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the formula (a1-2), the hydrocarbon group of n _a2 +1 valency in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and is usually saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, a ring-containing aliphatic hydrocarbon group, or a combination of a linear or branched aliphatic hydrocarbon group and a ring-containing aliphatic hydrocarbon group And specifically a group identical to Va ^{1 in the} above-mentioned formula (a1-1) can be mentioned.

The above-mentioned n _a2 + 1 is preferably 2 to 4, more preferably 2 or 3.

(31)

Wherein Ra ' ¹ and Ra' ² are each a hydrogen atom or an alkyl group, Ra ' ³ is a hydrocarbon group, and Ra' ³ is any of Ra ' ¹ and Ra' ² to form a ring. An acid-dissociable group represented by the general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid dissociable group" for convenience)

Examples of the alkyl group represented by Ra ' ¹ and Ra' ^{2 in} the formula (a1-r-1) include the same alkyl groups exemplified as substituent groups which may be bonded to the carbon atom at the α- And a methyl group or an ethyl group is preferable, and a methyl group is most preferable.

The hydrocarbon group of Ra ' ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and is preferably a linear or branched alkyl group. Specific examples thereof include a methyl group, Propyl group, isopropyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 2-dimethylpropyl group, 2,2-dimethylbutyl group and the like.

When Ra ' ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, and may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from the monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, and cyclooctane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from the polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobor Trichlorosilane, tetrachlorododecane, tetracyclododecane, and the like.

In the case where the aromatic hydrocarbon group is an aromatic ring, specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, etc. Part of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms Aromatic heterocyclic rings, and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group include a group in which one hydrogen atom is removed from the aromatic hydrocarbon ring (an aryl group), a group in which one hydrogen atom of the aryl group is substituted with an alkylene group (for example, a benzyl group, Butyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl and 2-naphthylethyl), and the like. The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

When Ra ' ³ is bonded to any of Ra' ¹ and Ra ' ² to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

Examples of the acid dissociable group for protecting a carboxyl group in the polar group include an acid dissociable group represented by the following general formula (a1-r-2) (an acid dissociable group represented by the following formula (a1-r-2) Quot; tertiary alkyl ester-type acid-dissociable group &quot; for convenience).

(32)

[In the formula, Ra ' ⁴ to Ra' ⁶ are hydrocarbon groups, and Ra ' ⁵ and Ra' ⁶ may combine with each other to form a ring.]

Ra ^'4 ~ Ra' as the hydrocarbon group of ⁶ are the same and the Ra ^'3. Ra ' ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. When Ra ' ⁵ and Ra' ⁶ are bonded to each other to form a ring, there may be mentioned groups represented by the following general formula (a1-r2-1).

On the other hand, when Ra ' ⁴ to Ra' ⁶ do not bond to each other and are independent hydrocarbon groups, there may be mentioned groups represented by the following general formula (a1-r2-2).

(33)

[Wherein, Ra ^'10 is a carbon number of alkyl group of 1 ~ 10, Ra'^11's, a group forming an aliphatic ring form together with the carbon atom ¹⁰ is bonded, Ra, Ra ¹² ~ Ra ^'14 are each independently a hydrocarbon Group.]

Equation (a1-r2-1) of the, exemplified as the "Ra in the alkyl group is formulas (a1-r-1) of the alkyl group having 1 to ¹⁰ 10 ^'3 linear or branched alkyl group of Ra One period is preferable. In the formula (a1-r2-1), preferred is exemplified as the alkyl group of cyclic 'Ra of the aliphatic cyclic group for ¹¹ the construction, expression (a1-r-1)' 3 Ra.

Equation (a1-r2-2) of, Ra ', and Ra ^{12' 14} Ra is ³ 'of the each independently preferably an alkyl group of 1 to 10 carbon atoms, and the alkyl group has the formula (a1-r-1) Is more preferably a straight chain or branched alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group.

Equation (a1-r2-2) of, Ra is preferably a linear, branched or cyclic alkyl group exemplified as the hydrocarbon groups of ^{3, 13,} formula (a1-r-1) Ra of the ' Do.

Among them, it is more preferable that R &lt; ³ &gt; is a group exemplified as a cyclic alkyl group.

Specific examples of the formula (a1-r2-1) are shown below. In the following formulas, &quot; * &quot;

(34)

Specific examples of the formula (a1-r2-2) are shown below.

(35)

Examples of the acid-dissociable group for protecting the hydroxyl group in the polar group include an acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as "tertiary alkyloxycarbonyl acid dissociable group" ).

(36)

Wherein Ra ' ⁷ to Ra' ⁹ represent an alkyl group.

In the formula (a1-r-3), Ra ' ⁷ to Ra' ⁹ are preferably an alkyl group having 1 to 5 carbon atoms, more preferably 1 to 3.

The total number of carbon atoms in each alkyl group is preferably from 3 to 7, more preferably from 3 to 5, and most preferably from 3 to 4.

As the above-mentioned formula (a1-2), a constituent unit represented by the following general formula (a1-2-01) is particularly preferable.

(37)

In the formulas (a1-2-01), Ra ² is an acid dissociable group represented by the formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, more preferably 1. R is the same as above.

Specific examples of the formula (a1-1) are shown below. In the following formulas, R ^? Is a hydrogen atom, a methyl group or a trifluoromethyl group.

(38)

[Chemical Formula 39]

(40)

(41)

(42)

Specific examples of the formula (a1-2) are shown below.

(43)

The proportion of the structural unit (a1) in the component (A) is preferably from 20 to 80 mol%, more preferably from 20 to 75 mol%, and still more preferably from 25 to 70 mol%, based on the total structural units constituting the component (A) % Is more preferable. By setting it to the lower limit value or more, lithography characteristics such as sensitivity, resolution, and LWR are improved. In addition, it is possible to achieve balance with other constituent units by making the content equal to or lower than the upper limit.

(The constituent unit (a2))

The structural unit (a2) is a structural unit containing a -SO ₂ -containing cyclic group, a carbonate-containing cyclic group or a -SO ₂ -containing cyclic group.

The -SO ₂ -containing cyclic group of the constituent unit (a2) is effective for enhancing the adhesion of the resist film to the substrate when the component (A) is used for forming a resist film.

In the present invention, the component (A) preferably contains the structural unit (a2).

When the structural unit (a1) includes a -SO ₂ -containing cyclic group in its structure, the structural unit also corresponds to the structural unit (a2) , And does not correspond to the structural unit (a2).

The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

(44)

Wherein R ²¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, Y ²¹ is a single bond or a divalent linking group, La ²¹ is -O-, -COO-, -CON R ') -, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. Provided that when La ²¹ is -O-, then Ya ²¹ is not -CO-. Ra ²¹ is a -SO ₂ -containing cyclic group, a lactone-containing cyclic group or a carbonate-containing cyclic group.]

The divalent linking group of Ya ²¹ is not particularly limited, and preferred examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a heteroatom.

(Bivalent hydrocarbon group which may have a substituent)

The hydrocarbon group as a divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in the structure. Specifically, the aliphatic hydrocarbon group represented by Va (Va) in the formula (a1-1) ^{1. &} Lt; / RTI &gt;

The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a substituent group containing a hetero atom in the ring structure, A group in which a hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, or a group in which the cyclic aliphatic hydrocarbon group is introduced in the midst of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same ones as described above.

The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

Specific examples of the cyclic aliphatic hydrocarbon group include the groups represented by Va ¹ in the above-mentioned formula (a1-1).

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group and a carbonyl group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and is preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, a n-butoxy group or a tert- , Ethoxy group is most preferable.

Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

Examples of the halogenated alkyl group as the substituent include groups in which a part or all of the hydrogen atoms of the alkyl group are substituted with the halogen atom.

The cyclic aliphatic hydrocarbon group may be substituted with a substituent group in which a part of the carbon atoms constituting the cyclic structure contains a hetero atom. The substituent containing the heteroatom is preferably -O-, -C (= O) -O-, -S-, -S (= O) _2- or -S (= O) ₂ -O-.

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include the groups exemplified by Va ¹ in the above-mentioned formula (a1-1).

In the aromatic hydrocarbon group, the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

Examples of the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

(A divalent linking group containing a hetero atom)

The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom.

When Y ^{&lt; a} &gt; is a divalent linking group containing a heteroatom, preferable examples of the linking group include -O-, -C (= O) -O-, -C (= O) -, -OC -, -C (= O) -NH-, -NH-, -NH-C (= NH) - (H may be substituted with a substituent such as an alkyl group or an acyl group) = O) ₂ -, -S (= O) ₂ -O-, a group represented by the formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C (= O) = O) -O- Y ²¹ , [Y ²¹ -C (= O) -O] _{m '} -Y ²² - or -Y ²¹ -OC (= O) -Y ²² - ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m 'is an integer of 0 to 3, and the like.

When the above-mentioned divalent linking group containing a heteroatom is -C (= O) -NH-, -NH- or -NH-C (= NH) -, the H may be substituted with a substituent such as an alkyl group or acyl . The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

Formula ^{-Y 21 -OY 22 -, -Y 21} -O-, -Y 21 -C (= O) -O-, -C (= O) -OY 21, - [Y 21 -C (= O) - O] _{m '-Y} ²² - or ^{-Y 21 -OC (= O) -Y} 22 - of, Y ²¹ and Y ²² are, each independently, a divalent hydrocarbon group which may have a substituent. The divalent hydrocarbon group may be the same as the "divalent hydrocarbon group which may have a substituent" exemplified in the description of the divalent linking group.

Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, particularly preferably a methylene group or an ethylene group.

Y ²² is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

In the group represented by the formula - [Y ²¹ -C (═O) -O] _{m '} -Y ²² -, m' is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1 , And 1 is particularly preferable. In short, as the group represented by the formula - [Y ²¹ -C (═O) -O] _{m '} -Y ²² -, a group represented by the formula -Y ²¹ -C (═O) -OY ²² - is particularly preferable. Among them, a group represented by the formula - (CH ₂ ) _{a '} -C (═O) -O- (CH ₂ ) _b' - is preferable. In the formula, a 'is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b 'is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.

In the present invention, Ya ^{21 is preferably a} single bond or an ester bond [-C (═O) -O-], an ether bond (-O-), a linear or branched alkylene group or a combination thereof .

In the formula (a2-1), Ra ²¹ is -SO ₂ - containing a cyclic group.

The "-SO ₂ -containing cyclic group" refers to a cyclic group containing a ring containing -SO ₂ - in the ring skeleton, and more specifically, the sulfur atom (S) in -SO ₂ - Is a cyclic group that forms part of the ring backbone of the ring. A ring containing -SO ₂ - in the ring skeleton is counted as the first ring, and in the case of only the ring, a monocyclic group or, in the case of having a further ring structure, it is called a polycyclic group regardless of its structure . The -SO ₂ -containing cyclic group may be monocyclic or polycyclic.

-SO as a hydrocarbon group of annular in R ¹ ₂ - containing cyclic group, in particular, those in the ring skeleton -O-SO ₂ - type ring containing group, i.e. -O-SO ₂ - in -OS- Is a cyclic group containing a sultone ring which forms part of the ring backbone. Specific examples of the -SO ₂ -containing cyclic group include the groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[Chemical Formula 45]

R &lt; ⁵¹ &gt; each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR &quot;, -OC (= O) R &quot;, a hydroxyalkyl group or a cyano group; Is an alkylene group, an oxygen atom or a sulfur atom of 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, and n 'is an integer of 0 to 2.]

In the general formulas (a5-r-1) to (a5-r-4), A "is the same as A" in the general formulas (a2-r-1) to (a2-r-7) described later. An alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR in ^{Ra '51 ", -OC (=} O) R", hydroxy alkyl group, the formula to be described later (a2-r-1) ~ (a2- is the same as r-7) of the Ra ^'21.

Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are described below. "Ac" in the formula represents an acetyl group.

(46)

(47)

(48)

As the -SO ₂ -containing cyclic group, the group represented by the general formula (a5-r-1) is preferable and the group represented by the general formulas (r-sl-1-1) at least one member selected from the group consisting of (r-sl-3-1) and (r-sl-4-1) 1) is most preferable.

The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C (═O) - in the cyclic skeleton. When a lactone ring is counted as the first ring, only a lactone ring is referred to as a monocyclic type group, and in the case of a further ring structure, it is referred to as a polycyclic type regardless of its structure. The lactone-containing cyclic group may be monocyclic or polycyclic.

The lactone-containing cyclic group as the cyclic hydrocarbon group for R ¹ is not particularly limited, and any cyclic group can be used. Specific examples thereof include groups represented by the following general formulas (a2-r-1) to (a2-r-7). Hereinafter, &quot; * &quot;

(49)

[Wherein, Ra ^'21 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ", -OC (= O ) R", hydroxy group or cyano group, and; R " An alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, n 'is an integer of 0 to 2, m' is 0 or 1, 1.]

In the general formulas (a2-r-1) to (a2-r-7), A "represents an alkyl group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) An oxygen atom, or a sulfur atom. The alkylene group having 1 to 5 carbon atoms in A "is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which -O- or -S- is interposed between the terminal or carbon atom of the alkylene group, for example, -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ - and the like. A "is preferably an alkylene group of 1 to 5 carbon atoms or -O-, more preferably an alkylene group of 1 to 5 carbon atoms, and most preferably a methylene group. Ra ^'21 are each independently, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR ", -OC (= O ) R", hydroxy group or cyano group.

Ra 'The alkyl group of the ^21, the alkyl group of 1 to 5 carbon atoms are preferred. Ra 'as the alkoxy group in ^21, is preferably an alkoxy group having 1 to 6 carbon atoms.

The alkoxy group is preferably a linear or branched chain. Specifically, there is a group with an oxygen atom (-O-) exemplified as the alkyl group in the above-mentioned Ra ^'21 include groups attached.

Ra 'The halogen atom in the ^21, and a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom is preferable.

Ra 'as the halogenated alkyl group in the ^21, wherein Ra' may be a group in which some or all of the hydrogen atoms of the alkyl group in ²¹ with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

Specific examples of the groups represented by the general formulas (a2-r-1) to (a2-r-7) are described below.

(50)

The "carbonate-containing cyclic group" means a cyclic group containing a ring (carbonate ring) containing -O-C (═O) -O- in the cyclic skeleton thereof. When the carbonate ring is counted as the first ring and only the carbonate ring has a monocyclic group and further another ring structure, the polycyclic group is called a polycyclic group regardless of its structure. The carbonate-containing cyclic group may be monocyclic or polycyclic.

As the cyclic hydrocarbon group containing cyclic hydrocarbon group in R ¹ , any cyclic group may be used without particular limitation. Specific examples thereof include groups represented by the following formulas (ax3-r-1) to (ax3-r-3).

(51)

[Wherein, Ra ^'x31 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxyl, -COOR ", -OC (= O ) R", hydroxy group or cyano group, and; R " Is an alkylene group, an oxygen atom or a sulfur atom of 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, and q 'is 0 or 1.]

A "in the general formulas (ax3-r-1) to (ax3-r-3) is the same as A" in the general formula (a2-r-1).

Ra ^'31 alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR in ", -OC (= O) R ", as the hydroxy group, respectively, the formula (a2-r-1) ~ (a2- r-7) are the same as those exemplified in the in Ra ^'21 described.

Specific examples of the groups represented by formulas (ax3-r-1) to (ax3-r-3) are described below.

(52)

Among them, the lactone-containing cyclic group is preferably a group represented by the general formula (a2-r-1) or (a2-r-2), more preferably a group represented by the formula (r-lc-1-1) .

The constituent unit (a2) of the component (A) may be one kind or two or more kinds.

When the component (A) has the structural unit (a2), the proportion of the structural unit (a2) is preferably from 1 to 80 mol%, more preferably from 5 to 5 mol% based on the total of all structural units constituting the component (A) To 70 mol%, more preferably 10 mol% to 65 mol%, and particularly preferably 10 mol% to 60 mol%. The effect of containing the constituent unit (a2) can be sufficiently obtained by setting the amount to not less than the lower limit, and when it is not more than the upper limit value, balance with other constituent units can be obtained, and various lithographic characteristics and pattern shapes are improved.

(The constituent unit (a3))

The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (except those corresponding to the structural units (a1) and (a2) described above).

The component (A) has the constituent unit (a3), so that the hydrophilicity of the component (A) increases, contributing to improvement in the resolution.

As the polar group, a hydroxyl group, a cyano group, a carboxyl group, a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group are substituted with a fluorine atom, and the like are exemplified.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) or a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, in the resin for a resist composition for an ArF excimer laser, a large number of proposed ones can be appropriately selected and used. The cyclic group is preferably a polycyclic group, more preferably 7 to 30 carbon atoms.

Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, a tricycloalkane, a tetracycloalkane or the like. Specific examples thereof include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isoborane, tricyclodecane and tetracyclododecane. Among these polycyclic groups, groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane are industrially preferable .

The constituent unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group.

As the structural unit (a3), a structural unit containing a polar group-containing aliphatic hydrocarbon group as a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the? -Position may be substituted with a substituent is preferable.

When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit (a3) is preferably a structural unit derived from a hydroxyethyl ester of acrylic acid, When the group is a cyclic group, preferred examples include a structural unit represented by the following formula (a3-1), a structural unit represented by the formula (a3-2), and a structural unit represented by the formula (a3-3)

(53)

Wherein R is as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, 1 is an integer of 1 to 5, s is It is an integer from 1 to 3.]

In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3-position and the 5-position of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

j is preferably 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of adamantyl group.

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or the 6-position of the norbornyl group.

In formula (a3-3), t 'is preferably 1. l is preferably 1. s is preferably 1. In these, it is preferable that a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxyl group of acrylic acid. It is preferable that the fluorinated alkyl alcohol is bonded to the 5th or 6th position of the norbornyl group.

The constituent unit (a3) contained in the component (A) may be one kind or two or more kinds.

The proportion of the structural unit (a3) in the component (A) is preferably from 5 to 50 mol%, more preferably from 5 to 40 mol%, based on the total of all the structural units constituting the resin component (A) , More preferably from 5 to 25 mol%.

When the proportion of the structural unit (a3) is at least the lower limit value, the effect of incorporating the structural unit (a3) is sufficiently obtained. When the proportion is at most the upper limit, balance with other structural units becomes easy.

(Constituent unit (a4))

The structural unit (a4) is a structural unit containing an acidic cyclic group. When the component (A) has the structural unit (a4), dry etching resistance of the formed resist pattern is improved. Further, the hydrophobicity of the component (A) is increased. It is considered that the improvement of the hydrophobicity contributes to the improvement of the resolution and the shape of the resist pattern, especially in the case of organic solvent development.

The "acid-dissociable cyclic group" in the constituent unit (a4) is an acid-dissociable cyclic group in which when an acid is generated from a component (B) described later by exposure, to be.

As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an aliphatic cyclic group of acid-labile groups is preferable. The cyclic group may, for example, be the same as those exemplified above for the structural unit (a1), and examples thereof include a resist such as ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser) A number of conventionally known ones used as the resin component of the composition can be used.

Particularly, at least one member selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group and a norbornyl group is preferable from the viewpoint of industrial availability and the like. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7).

(54)

[Wherein R ^{? Represents} a hydrogen atom, a methyl group or a trifluoromethyl group]

The constituent unit (a4) contained in the component (A) may be one type or two or more types.

When the constituent unit (a4) is contained in the component (A), the proportion of the constituent unit (a4) is preferably from 1 to 30 mol%, more preferably from 10 to 30 mol% based on the total constituent units constituting the component By mole to 20% by mole.

The component (A) may be a copolymer obtained by arbitrarily combining (a1) to (a4).

The component (A) is obtained by polymerizing monomers which derive each constituent unit by, for example, known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate have.

Further, (A) component, by using at the time of the polymerization, for example, by combined use of a chain transfer agent such as _{HS-CH 2 -CH 2 -CH 2} -C (CF 3) 2 -OH, -C at the terminal ( CF ₃ ) ₂ -OH group may be introduced. As described above, a copolymer into which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced is effective for reduction of development defects and reduction of LER (line edge roughness: uneven irregularity of line side wall).

In the present invention, the weight average molecular weight (Mw) of the component (A) (based on polystyrene conversion by gel permeation chromatography) is not particularly limited and is preferably from 1,000 to 50,000, more preferably from 1,500 to 30,000 , And most preferably from 2,000 to 20,000. If it is below the upper limit of the range, there is a solubility in a resist solvent sufficient for use as a resist. If the lower limit of the above range is exceeded, the dry etching resistance and the cross-sectional shape of the resist pattern are favorable.

In the resist composition of the present invention, the component (A) may be used alone or in combination of two or more.

The resin or the content of the component (A) in the resist composition of the present invention may be adjusted according to the required resist properties to be formed, but it is preferable to employ a polyhydroxystyrene resin.

&Lt; Basic compound component: (D) component &gt;

The resist composition of the present invention may further contain, in addition to the component (A) or the component (A) and the component (B), an acid diffusion control agent component (hereinafter also referred to as "component (D) do.

The component (D) acts as a quencher (acid diffusion control agent) for trapping an acid generated by exposure from the component (B) or the like.

The component (D) in the present invention may be a photo-degradable base (D1) which is decomposed by exposure to lose its acid diffusion controllability (hereinafter referred to as "component (D1)") (Hereinafter referred to as &quot; component (D2) &quot;).

[Component (D1)] [

(D1), it is possible to improve the contrast between the exposed portion and the non-exposed portion when forming a resist pattern.

The component (D1) is not particularly limited as long as it is decomposed by exposure to lose acid diffusion controllability, and a compound represented by the following general formula (d1-1) (hereinafter referred to as a "component (d1-1) A compound represented by the following general formula (d1-2) (hereinafter referred to as a "component (d1-2)") and a compound represented by the following general formula (d1-3) ) Is preferable.

(d1-1) to (d1-3) do not act as a quencher and act as a quencher in the unexposed portion because they dissolve in the exposed portion and lose acid diffusion controllability (basicity).

(55)

[Wherein, Rd Rd ¹ ~ ⁴ is an alkenyl group of chain which may have a cyclic group which may have a substituent, an alkyl chain which may have a substituent, or a substituent. It is to be noted that the fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. M ^&lt; ^{m + &gt;} are each independently an m-valent organic cation.

{(D1-1) component}

· Anonymous

Formula (d1-1) of, Rd ¹ is an alkenyl group which may have a chain-like alkyl group, or a substituent of the chain which may have a cyclic group, substituents may have a substituent, the same groups as R ¹⁰¹ have.

Among them, Rd ^{1 is preferably} an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like hydrocarbon group which may have a substituent. The substituent which these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.

The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.

The aliphatic cyclic group is more preferably a group obtained by removing at least one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.

The chain type hydrocarbon group is preferably a chain type alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms and specifically includes straight chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, Chain alkyl group having 1 to 4 carbon atoms, such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2- methylbutyl, 3- methylbutyl, Methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

When the above chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably from 1 to 11, more preferably from 1 to 8, still more preferably from 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atoms other than the fluorine atom include an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms and the fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms A linear perfluoroalkyl group).

Preferred examples of the anion moiety of the component (d1-1) are shown below.

(56)

· Kattenbu

In the formula (d1-1), M ^{m +} is an organic cation of m.

The organic cation of M ^{m +} is not particularly limited, and examples thereof include the same cations represented by the general formulas (ca-1) to (ca-4) 1) to (ca-1-63) are preferable.

The component (d1-1) may be used singly or in combination of two or more.

{(D1-2) component}

· Anonymous

Formula (d1-2) of, Rd ² is an alkenyl group of chain which may have a ring which may have a substituent group type group, an alkyl group of chain which may have a substituent, or a substituent, and R ¹⁰¹ include the same .

Provided that a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² (not substituted with fluorine). As a result, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the hardenability of the component (D) is improved.

Rd ² is preferably an aliphatic cyclic group which may have a substituent, and a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. More preferably a group obtained by removing one or more hydrogen atoms from Campa and the like.

The hydrocarbon group of Rd ² may have a substituent, and the substituent may be the same as the substituent which the hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the formula (d1-1) may have .

Preferred examples of the anion moiety of the component (d1-2) are shown below.

(57)

· Kattenbu

In the formula (d1-2), M ^{m +} is an organic cation of ^m, and is the same as M ^{m +} in the formula (d1-1).

The component (d1-2) may be used singly or in combination of two or more.

{(D1-3) component}

· Anonymous

Formula (d1-3) of, Rd ³ is an alkenyl group which may have a chain-like alkyl group, or a substituent of the chain which may have a cyclic group, substituents may have a substituent, the same groups as R ¹⁰¹ And is preferably a cyclic group containing a fluorine atom, a chain-like alkyl group, or a chain-like alkenyl group. Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group of Rd ¹ is more preferable.

Formula (d1-3) of, Rd is ^4, and alkenyl groups of chain which may have a ring which may have a substituent group type group, an alkyl group of chain which may have a substituent, or a substituent, and R ¹⁰¹ include the same .

Among them, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which may have a substituent are preferable.

The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Part of the hydrogen atoms of the alkyl group Rd is ⁴ may be substituted by a hydroxyl group, a cyano group or the like.

The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso- Butoxy group, and tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferable.

The alkenyl group in Rd ⁴ may be the same as those described above for R ¹⁰¹ , preferably a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group or a 2-methylpropenyl group. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

The cyclic group in Rd ⁴ includes the same groups as those described above for R ^21, and the cyclic group in the cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane An alicyclic group in which at least one hydrogen atom is removed, or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, and lithography characteristics are improved. When Rd ⁴ is an aromatic group, the resist composition is excellent in light absorption efficiency in lithography using EUV or the like as an exposure light source, and sensitivity and lithography characteristics are improved.

In the formula (d1-3), Yd ¹ is a single bond, or a divalent connecting group.

The divalent linking group in Yd ¹ is not particularly limited, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. These are the same as those exemplified in the explanation of the divalent linking group of Ya ²¹ in the formula (a2-1).

Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, more preferably a methylene group or an ethylene group.

Preferred examples of the anion moiety of the component (d1-3) are shown below.

(58)

[Chemical Formula 59]

· Kattenbu

In the formula (d1-3), M ^{m +} is an organic cation of ^m, and is the same as M ^{m +} in the formula (d1-1).

The component (d1-3) may be used singly or in combination of two or more.

As the component (D1), any one of the components (d1-1) to (d1-3) may be used, or two or more components may be used in combination.

The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and further preferably 1 to 8 parts by mass with respect to 100 parts by mass of the component (A).

When the content of the component (D1) is a preferable lower limit value or more, particularly good lithography characteristics and resist pattern shapes are obtained. On the other hand, if it is less than the upper limit value, the sensitivity can be kept good and the throughput is also excellent.

The method for producing the above components (d1-1) and (d1-2) is not particularly limited and can be produced by a known method.

The content of the component (D1) is preferably 0.5 to 10.0 parts by mass, more preferably 0.5 to 8.0 parts by mass, and further preferably 1.0 to 8.0 parts by mass with respect to 100 parts by mass of the component (A). When the lower limit of the above range is exceeded, particularly good lithographic properties and resist pattern shapes are obtained. Below the upper limit of the above range, the sensitivity can be kept good and the throughput is excellent.

(Component (D2))

The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as a component (D2)) which does not correspond to the component (D1).

The component (D2) is not particularly limited as long as it functions as an acid diffusion control agent and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, especially secondary aliphatic amines and tertiary aliphatic amines are preferred.

The aliphatic amine is an amine having at least one aliphatic group, and the aliphatic group preferably has 1 to 12 carbon atoms.

Examples of the aliphatic amine include an amine (alkylamine or alkyl alcohol amine) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms, or a cyclic amine.

Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; monoalkylamines such as diethylamine, di- , Dialkylamines such as di-n-heptylamine, di-n-octylamine and dicyclohexylamine; aliphatic amines such as trimethylamine, triethylamine, tri-n-propylamine, Trialkylamines such as triethylamine, triethylamine, triethylamine, n-hexylamine, triethylamine, triethylamine, And alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine and tri-n-octanolamine. Of these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

As the cyclic amine, there can be mentioned, for example, heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).

Specific examples of the aliphatic monocyclic amine include piperidine, piperazine and the like.

As the aliphatic polycyclic amines, the number of carbon atoms is preferably from 6 to 10, and specific examples include 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] Undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

Examples of other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) Amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} Tris [2- {2- (2-hydroxyethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine may be used.

Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N -tet-butoxycarbonylpyrrolidine and the like.

(D2) may be used alone or in combination of two or more.

The component (D2) is usually used in a range of 0.01 to 5.0 parts by mass based on 100 parts by mass of the component (A). By setting the resistivity to the above range, the resist pattern shape, time-course stability after exposure, and the like are improved.

The component (D) may be used singly or in combination of two or more kinds.

When the resist composition of the present invention contains the component (D), the amount of the component (D) is preferably 0.1 to 15 parts by mass, more preferably 0.3 to 12 parts by mass, relative to 100 parts by mass of the component (A) More preferably 0.5 to 12 parts by mass. When the lower limit of the above range is exceeded, lithographic characteristics such as LWR are further improved when the resist composition is used. In addition, a better resist pattern shape can be obtained. Below the upper limit of the above range, the sensitivity can be kept good and the throughput is excellent.

<Optional ingredients>

[Component (E)] [

In the present invention, for the purpose of preventing the deterioration of sensitivity, and improving the resist pattern shape and time-course stability after exposure, the resist composition may contain, as optional components, an organic carboxylic acid, (Hereinafter referred to as a component (E)) selected from the group consisting of the compounds (A) and (B).

As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are preferable.

Examples of the phosphoric acid include phosphoric acid, phosphonic acid, and phosphinic acid. Of these, phosphonic acid is particularly preferable.

Examples of the derivative of the oxo acid of phosphorus include ester in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, .

Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.

Examples of the phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester and phosphonic acid dibenzyl ester.

Examples of derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid.

The component (E) may be used alone or in combination of two or more.

The component (E) is usually used in a range of 0.01 to 5.0 parts by mass based on 100 parts by mass of the component (A).

[Component (F)] [

In the present invention, the resist composition may contain a fluorine additive (hereinafter referred to as "component (F)") to impart water repellency to the resist film.

Examples of the component (F) include, for example, those described in JP-A No. 2010-002870, JP-A No. 2010-032994, JP-A No. 2010-277043, JP-A No. 2011-13569, Fluorinated polymer compounds described in JP-A-2011-128226 can be used.

More specifically, as the component (F), a polymer having a structural unit (f1) represented by the following formula (f1-1) may be mentioned. Examples of the polymer include a polymer (homopolymer) composed only of the structural unit (f1) represented by the following formula (f1-1), a structural unit (f1) represented by the following formula (f1-1) Is preferably a copolymer of the structural unit (f1) represented by the following formula (f1-1), the structural unit derived from acrylic acid or methacrylic acid, and the aforementioned structural unit (a1). Examples of the structural unit (a1) copolymerized with the structural unit (f1) represented by the following formula (f1-1) include 1-ethyl-1-cyclooctyl (meth) acrylate, Is preferable.

(60)

Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf ¹⁰² and Rf ¹⁰³ may be the same or different, They may be the same or different. nf ¹ is an integer of 1 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom.]

In the formula (f1-1), R is the same as the above. As R, a hydrogen atom or a methyl group is preferable.

Examples of the halogen atom of Rf ¹⁰² and Rf ^{103 in} the formula (f1-1) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include the same groups as those for the alkyl group having 1 to 5 carbon atoms for R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include groups in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable. Among them, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and are preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group.

In the formula (f1-1), ¹ nf is an integer from 1 to 5, more preferably an integer of 1 to 3 is preferable, 1 or 2;

In the formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.

The hydrocarbon group containing a fluorine atom may be any one of a linear chain, a branched chain and a cyclic group. The number of carbon atoms is preferably from 1 to 20, more preferably from 1 to 15, Particularly preferred.

In the hydrocarbon group containing a fluorine atom, it is preferable that at least 25% of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably at least 50% of the fluorine atoms are fluorinated, and more preferably at least 60% Is particularly preferable in that the hydrophobicity of the resist film upon immersion exposure is high.

Among them, a fluorinated hydrocarbon group having 1 to 5 carbon atoms is particularly preferable as Rf ¹⁰¹ , and a methyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH (CF ₃ ) ₂ , -CH ₂ - CH ₂ -CF ₃ , -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are most preferred.

The weight average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography) of the component (F) is preferably from 1,000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. If it is below the upper limit of the range, there is a solubility in a resist solvent sufficient for use as a resist. If the lower limit of the above range is exceeded, the dry etching resistance and the cross-sectional shape of the resist pattern are favorable.

The dispersion degree (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

The component (F) may be used alone or in combination of two or more.

The component (F) is usually used in a proportion of 0.5 to 10 parts by mass based on 100 parts by mass of the component (A).

In the present invention, the resist composition may further contain miscible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, a halation inhibitor, It can be appropriately added and contained.

[Component (S)] [

In the present invention, the resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as component (S)).

As the component (S), any one that can dissolve each component to be used and make it a homogeneous solution may be used. Any one of conventionally known solvents for chemically amplified resists may be appropriately selected and used .

For example, lactones such as? -Butyrolactone, ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone (2-heptanone), methyl isopentyl ketone, Polyhydric alcohols such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; polyhydric alcohols such as polyhydric alcohols such as diethylene glycol monoacetate, diethylene glycol monoacetate, Derivatives of polyhydric alcohols such as alcohols or compounds having an ether bond such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, monoalkyl ether or monophenyl ether of compounds having an ester bond Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) is preferred); cyclic ethers such as dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate Benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene , Aromatic organic solvents such as cymene and mesitylene, dimethylsulfoxide (DMSO) and the like.

These organic solvents may be used alone or in combination of two or more.

Among them, PGMEA, PGME,? -Butyrolactone and EL are preferable.

A mixed solvent in which PGMEA and a polar solvent are mixed is also preferable. The compounding ratio (mass ratio) may be suitably determined in consideration of the compatibility of the PGMEA and the polar solvent, and is preferably within the range of 1: 9 to 9: 1, more preferably 2: 8 to 8: 2 desirable.

More specifically, when EL or cyclohexanone is blended as a polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. When PGME is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, still more preferably 3: 7: 3.

Further, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and? -Butyrolactone is also preferable. In this case, as the mixing ratio, the mass ratio of the former to the latter is preferably 70:30 to 95: 5.

The amount of the component (S) to be used is not particularly limited and is appropriately set in accordance with the thickness of the coating film at a concentration applicable to a substrate or the like. In general, the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

The resist composition of the present invention may further contain miscible additives such as an additive resin for improving the performance of a resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, a halation inhibitor, Can be added and contained.

According to the resist pattern forming method and the resist composition of the present invention, a resist pattern having good lithography characteristics can be formed even when a support having a high reflectivity such as a stepped substrate is employed. The reason is presumed as follows.

In the present invention, since the compound (b1) contains an ether group (i.e., an oxygen atom) in the cation portion, it is considered that the polarity increases and is uniformly distributed in the resist film. Therefore, it is presumed that the shape of the column when the focus is changed is maintained. It is also considered that the anion portion of (b1) is small and the diffusion length of the acid is in a tendency toward long diffusion. As a result, it is presumed that the acid generated in the exposed portion diffuses and the roughness of the side wall is reduced.

In (b2), the anion portion has a cubic bulky structure with a large volume. Therefore, it is presumed that the diffusion of the anion (acid) is chemically and physically inhibited.

In the present invention, it is presumed that (b1) and (b2) act synergistically to form a resist pattern having good lithography characteristics even when the reflectance of the support is high.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

&Lt; Preparation of resist composition &gt;

Each component shown in Table 1 was mixed and dissolved to prepare a resist composition.

The abbreviations in the above table have the following meanings. The numerical value in [] is the compounding amount (parts by mass).

(A) -1: The following polymer compound (A) -1.

(B-1) to (B-2), (B-11)

The following compounds (B-1) to (B-2), (B-11), (B-21) to (B-22) and (B-3).

(D) -1: trioctylamine.

(E) -1: Salicylic acid.

(S) -1: mixed solvent of PGMEA / PGME / ethyl lactate (mass ratio 50/25/25).

(61)

(62)

&Lt; Formation of resist pattern &

A known organic antireflection film composition was applied on an 8-inch silicon wafer using a spinner and baked on a hot plate at 205 DEG C for 60 seconds and dried to form an organic antireflection film having a thickness of 120 nm, Barrier coating substrate.

The n value (optical refractive index) and the k value (light absorption rate) of the substrate coated with the organic anti-reflection film were measured, and the reflectance was calculated therefrom. As a result, The reflectance was 6.6%.

Subsequently, the resist compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were applied on the organic anti-reflective coating film-applied substrate using a spinner, and prebake (preliminary baking) on a hot plate at 120 DEG C for 90 seconds PAB) treatment was carried out and dried to form a resist film having a film thickness of 277 nm.

Then, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through each mask pattern (binary mask) using an exposure apparatus NSR-S205C (NA = 0.751 / 2 annular manufactured by Nikon Corporation).

Next, an alkali development was carried out for 60 seconds at 23 占 폚 using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).

Thereafter, post exposure baking treatment (PEB) was performed at 120 캜 for 90 seconds.

As a result, the following patterns were formed, respectively.

Pattern 1: Space and line (SL) pattern with a space width of 120 nm and a pitch width of 260 nm

Pattern 2: Space and line pattern with a space width of 120 nm and a pitch width of 1650 nm

Pattern 3: Line and space (LS) pattern with a line width of 120 nm and a pitch width of 1760 nm

[Evaluation of optimum exposure dose (Eop)] [

The optimum exposure dose Eop (mJ / cm &lt; 2 &gt;) at which the LS pattern of the target size is formed was obtained by the above-described method of forming a resist pattern. The results are shown in Table 2 as &quot; Sensitivity (mJ / cm 2) &quot;.

[Evaluation of shape]

The LS pattern was observed with a line SEM (scanning electron microscope, acceleration voltage 800 V, trade name: S-9220, manufactured by Hitachi, Ltd.) in the resist pattern formation. The results are shown in Table 2 as &quot; shape of pattern side wall &quot; or &quot; shape of pattern tower &quot;.

In Table 2, &quot; Shape of pattern side wall &quot; indicates that the pattern side wall is smooth and excellent in rectangularity, and &amp; cir &amp;

In the following Table 2, &quot; shape of pattern tower &quot; indicates that the shape collapse of the tower was shown as x, and that the shape of the tower was not collapsed.

Evaluation of depth of focus (DOF)

The depth of focus DOF in the formation of the resist pattern was evaluated.

In the Eop, the focus was appropriately shifted up and down, and a resist pattern was formed in the same manner as in the resist pattern formation in Examples 1 to 3 and Comparative Examples 1 to 3, and a range in which the shape of the SL pattern or LS pattern was obtained (Nm) of the depth of focus. The results are shown in Table 2.

As shown in the above results, when the resist patterns of Examples 1 to 3 were used to form a resist pattern, the resist pattern formed using the resist compositions of Comparative Examples 1 to 3 had a better pattern shape, A good pattern of DOF was also formed.

Claims (8)

A step of forming an acid on the support by exposure to light and forming a resist film by using a resist composition which is changed in solubility in a developing solution by the action of an acid; a step of exposing the resist film; A method for forming a resist pattern, the method comprising:
Wherein the resist composition contains an acid generator and the acid generator comprises a compound (b1) having a sulfonium cation that contains an ether group and a compound (b2) represented by the following formula (b2) Wherein the resist pattern is a resist pattern.
[Chemical Formula 1]

Wherein R ²¹ is a cyclic group which may have a substituent.
R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.
Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.
V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.
M ' ^{m +} is an organic cation of m. The method according to claim 1,
Wherein the compound (b1) is a compound represented by the following general formula (b1-1).
(2)

[Wherein R ¹¹ to R ¹³ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. Provided that at least one of R ¹¹ to R ¹³ contains an ether group. R ¹¹ to R ¹³ may bond to each other to form a ring with the sulfur atom in the formula.
And R &lt; ^{41 &gt;} is a chain-like fluorinated alkyl group. The method according to claim 1,
Wherein a reflectance of the support with respect to light having a wavelength of an exposure light source is 1.0% or more. 4. The method according to any one of claims 1 to 3,
Wherein the resist composition contains at least one resin selected from the group consisting of a novolak resin, a polyhydroxystyrene resin, and an acrylic resin. A resist composition which generates an acid upon exposure and which has a solubility in a developer changed by the action of an acid,
Wherein the acid generator comprises a compound (b1) having a sulfonium cation in an ether group and a compound (b2) represented by the following general formula (b2).
(3)

Wherein R ²¹ is a cyclic group which may have a substituent.
R ²² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.
Y ²¹ is a single bond or a divalent linking group containing an oxygen atom.
V ²¹ is a single bond, an alkylene group, or a fluorinated alkylene group.
M ' ^{m +} is an organic cation of m. 6. The method of claim 5,
Wherein the compound (b1) is a compound represented by the following general formula (b1-1).
[Chemical Formula 4]

[Wherein R ¹¹ to R ¹³ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. Provided that at least one of R ¹¹ to R ¹³ contains an ether group. R ¹¹ to R ¹³ may bond to each other to form a ring with the sulfur atom in the formula.
And R &lt; ^{41 &gt;} is a chain-like fluorinated alkyl group. The method according to claim 6,
Wherein the resist composition is used for forming a resist pattern on a support having a reflectance of 1.0% or more with respect to light having a wavelength of an exposure light source. 8. The method according to any one of claims 5 to 7,
A novolak resin, a polyhydroxystyrene resin, and an acrylic resin.