JP6539499B2 - Resist pattern formation method - Google Patents

Description

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

In the lithography technique, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to radiation such as light or electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern of a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property of being dissolved in the developer is referred to as a positive type, and a resist material in which the exposed portion is changed to a property not to be dissolved in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, miniaturization of patterns is rapidly progressing with advances in lithography technology.
Generally as a method of refinement | miniaturization, shortening of the wavelength (exposure) of the exposure light source is performed. Specifically, conventionally, ultraviolet rays represented by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has been started. In addition, electron beams with a wavelength (high energy) shorter than those of these excimer lasers, EUV (extreme ultraviolet), X-rays, and the like are also being studied.

  As a method of providing a finer pattern, a double patterning process has been proposed in which patterning is performed multiple times to form a resist pattern. According to the double patterning process, for example, the first resist pattern is formed on the support by patterning using the first resist composition, and then the first resist pattern is formed. By performing patterning on the support using the second resist composition, it is possible to form a resist pattern with higher resolution than a resist pattern formed by one patterning.

Further, in Patent Document 1, a first resist pattern is formed on a support, an SiO ₂ film is formed on the support on which the first resist pattern is formed, and etching is performed using the SiO ₂ film as a sacrificial film. And then removing the first resist pattern to form a second pattern of SiO ₂ film.

JP, 2013-164509, A

However, the method as described above has a problem that a plurality of exposures are required and the number of steps is large and processing is complicated, and there is still room for improvement in the method of forming a fine pattern.
The present invention has been made in view of the above circumstances, and provides a resist pattern forming method capable of forming a fine pattern, and a resist composition for forming a split pattern suitably used for the resist pattern forming method. To be an issue.

  According to a first aspect of the present invention, a positive resist composition is coated on a support, a positive resist film is formed, the positive resist film is exposed, alkali development is performed, and a first resist pattern is formed. A solution containing an acid or a thermal acid generator is coated on the support on which the first resist pattern is formed, and a step A of forming a first resist pattern, Step B of obtaining a structure including a first resist pattern and a first layer covering the resist pattern 1; heating the structure; and the action of an acid generated from the acid or the thermal acid generator; the first resist Step C of changing the solubility of the pattern in the developer, and developing the heated structure with an organic solvent to remove regions other than the region in which the solubility of the first resist pattern in the developer has changed, Split putter C. forming the resist pattern forming step, wherein the positive resist composition contains an acid diffusion control agent, and the acid diffusion control agent has an acid dissociation constant (pKa) of 3.0. It is a resist pattern formation method characterized by including the above acids.

  A second aspect of the present invention is a positive resist composition used in the method of forming a resist pattern according to the first aspect of the present invention, which generates an acid upon exposure to light, and acts on the developer by the action of the acid. It is a positive resist composition with increased solubility, and contains an acid diffusion controller, and the acid diffusion controller contains an acid having an acid dissociation constant (pKa) of 3.0 or more. Positive-working resist composition.

  According to the present invention, it is possible to provide a resist pattern formation method capable of forming a fine pattern, and a resist composition for split pattern formation suitably used for the resist pattern formation method.

It is a figure which shows the general | schematic process of 1st Embodiment of the resist pattern formation method of this invention. It is a figure which shows the general | schematic process of 2nd Embodiment of the resist pattern formation method of this invention.

In the present specification and claims, “aliphatic” is a concept relative to an aromatic and is defined to mean a group, a compound or the like having no aromaticity.
The term "alkyl group" is intended to include linear, branched and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified.
The "alkylene group" is intended to include a linear, branched and cyclic divalent saturated hydrocarbon group unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which 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 part or all of the hydrogen atoms of the alkyl group or the alkylene group are substituted with a fluorine atom.
The "constituent unit" means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
The “constituent unit derived from acrylic acid ester” means a constitutional unit formed by cleavage of the ethylenic double bond of acrylic acid ester.
The “acrylic ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ = CH—COOH) is substituted with an organic group.
In the acrylic ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted by a substituent. The substituent (R ^α ) for substituting the hydrogen atom bonded to the carbon atom at the α-position is an atom or a group other than a hydrogen atom, and is, for example, an alkyl group of 1 to 5 carbon atoms, a halogenation of 1 to 5 carbon atoms Alkyl groups, hydroxyalkyl groups and the like can be mentioned. In addition, the carbon atom of alpha-position of acrylic acid ester is a carbon atom which the carbonyl group has couple | bonded, unless there is particular notice.
Hereinafter, an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α position is substituted with a substituent may be referred to as an α-substituted acrylic acid ester. Moreover, an acrylic ester and an alpha substituted acrylic ester may be included and it may be called "(alpha substituted) acrylic ester."
The “constituent unit derived from hydroxystyrene derivative” means a constitutional unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
The term "hydroxystyrene derivative" is a concept including those in which a hydrogen atom at the alpha position of hydroxystyrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. As their derivatives, those in which the hydrogen atom of hydroxystyrene which may be substituted with a hydrogen atom at the alpha position is substituted with an organic group, or even if the hydrogen atom at the alpha position is substituted with a substituent What has substituents other than a hydroxyl group couple | bonded with the benzene ring of good hydroxystyrene, etc. are mentioned. The alpha position (carbon atom at the alpha position) refers to the carbon atom to which the benzene ring is bonded unless otherwise specified.
As a substituent which substitutes the hydrogen atom of alpha position of hydroxystyrene, the thing similar to what was mentioned as a substituent of alpha position in the above-mentioned alpha substitution acrylic acid ester is mentioned.
The “constituent unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative” means a constitutional unit formed by cleavage of an ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.
The "vinyl benzoic acid derivative" is a concept including those in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with an alkyl group, another substituent such as a halogenated alkyl group, and derivatives thereof. As their derivatives, those in which the hydrogen atom in the alpha position is substituted with an organic group and the hydrogen atom in the carboxy group of vinyl benzoic acid which may be substituted with a substituent, or the hydrogen atom in the alpha position is substituted with a substituent And those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid which may be mentioned. The alpha position (carbon atom at the alpha position) refers to the carbon atom to which the benzene ring is bonded unless otherwise specified.
The "styrene derivative" means that the hydrogen atom at the alpha position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
The “structural unit derived from styrene” and the “structural unit derived from a styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.
The alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (a methyl group, an ethyl group, a propyl group, an isopropyl group) , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
In addition, specific examples of the halogenated alkyl group as a substituent at the α-position include groups in which part or all of the hydrogen atoms of the above “alkyl group as a substituent at the α-position” are substituted with a halogen atom Be 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.
Further, specific examples of the hydroxyalkyl group as a substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as a substituent at the α-position” are substituted with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.
When it is described that "it may have a substituent", when substituting a hydrogen atom (-H) with a monovalent group and when substituting a methylene group (-CH _2- ) with a divalent group Including both.
"Exposure" is a concept that includes general radiation irradiation.

«Method for forming resist pattern»
According to a first aspect of the present invention, a positive resist composition is coated on a support, a positive resist film is formed, the positive resist film is exposed, alkali development is performed, and a first resist pattern is formed. A step A of forming the first layer, and a step B of forming a first layer by applying a solution containing an acid or a thermal acid generator so as to cover the first resist pattern; Heating the structure including the first resist pattern, and changing the solubility of the first resist pattern in a developer by the action of the acid in the first layer; And D) developing the first resist pattern with an organic solvent, removing the region other than the region where the solubility of the first resist pattern in the developing solution has changed, and forming a second resist pattern.
The positive resist composition used in the step A contains an acid diffusion controller component, and the acid diffusion controller component contains an acid having an acid dissociation constant (pKa) of 3.0 or more.
Hereinafter, the method for forming a resist pattern according to this aspect will be described with reference to the drawings.

First Embodiment
FIG. 1 shows a schematic process of the resist pattern forming method of the first embodiment. FIGS. 1A to 1D each show a cross section of a resist pattern.
In this embodiment, the composition contains an acid diffusion control agent containing an acid having an acid dissociation constant (pKa) of 3.0 or more, and a base component (A) whose solubility in an alkali developer is increased by the action of the acid. Positive resist compositions have been used.
First, as shown in FIG. 1A, a resist pattern 1P of line and space is formed on a support 1 using the positive resist composition (Step A).
Next, as shown in FIG. 1B, a solution containing an acid or a thermal acid generator is applied so as to cover resist pattern 1P, and a first layer covering first resist pattern 1P and this. The structure 3 which consists of 2 is obtained (process B).
Thereafter, the structure 3 is heated, and as shown in FIG. 1C, the solubility of the surface of the first resist pattern 1P in the developing solution is changed (step C).
Thereafter, organic solvent development is performed, and the portion indicated by 1Pb in FIG. 1C is removed, whereby the first resist pattern is divided into lines, spaces, and lines as shown in FIG. ), And a fine pattern (sometimes referred to as "split pattern") is formed (step D).

[Step A]
Step A is a step of applying a positive resist composition on a support to form a positive resist film, exposing the positive resist film, and alkali developing to form a first resist pattern. is there. The positive resist composition used in step A will be described later.
The formation of the positive resist film can be performed by a conventionally known method. Specifically, for example, a positive resist composition is coated on a support by a spinner or the like, and baked at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90 seconds (prebake By applying PAB))), a positive resist film can be formed.
The thickness of the positive resist film is not particularly limited, and is preferably in the range of 30 to 250 nm, and more preferably 50 to 150 nm.

The support is not particularly limited, and conventionally known ones can be used, and examples thereof include a substrate for an electronic component, and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon wafer, a metal substrate such as copper, chromium, iron, aluminum or the like, a glass substrate, etc. may be mentioned. As a material of the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
In addition, as the support, an inorganic and / or organic film may be provided on the substrate as described above. Examples of inorganic films include inorganic antireflective films (inorganic BARCs). Examples of the organic film include organic films such as an organic antireflective film (organic BARC) and a lower organic film in a multilayer resist method.
Here, in the multilayer resist method, at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and a resist pattern formed on the upper resist film is used as a mask. It is a method of patterning the lower organic film, and is said to be able to form a pattern with a high aspect ratio. That is, according to the multilayer resist method, since the required thickness can be secured by the lower layer organic film, the resist film can be thinned, and a fine pattern with a high aspect 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 (bilayer resist method), and one or more intermediate layers between the upper layer resist film and the lower layer organic film It is divided into the method (three-layer resist method) of forming a multilayer structure of three or more layers provided with (metal thin film etc.).

The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. It can be done using radiation. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV.

The exposure method of the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be a liquid immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lowermost lens of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state It is an exposure method.
As the immersion medium, a solvent having a refractive index which is larger than the refractive index of air and smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of the solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index 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 silicon-based solvent, a hydrocarbon-based solvent and the like.
Specific examples of the fluorine-based inert liquid include fluorine-based compounds 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 as main components. A liquid etc. are mentioned, The thing of 70-180 degreeC of boiling points is preferable, and the thing of 80-160 degreeC is more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range, since the medium used for immersion can be removed by a simple method after the completion of exposure.
As the fluorine-based inert liquid, particularly preferred is a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.
Furthermore, specifically, as the perfluoroalkylether compound, perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.) can be mentioned, and as the perfluoroalkylamine compound, perfluorotributylamine ( Boiling point 174 ° C.) can be mentioned.
Water is preferably used as the immersion medium from the viewpoints of cost, safety, environmental problems, versatility and the like.

  As an alkali developing solution used for alkali image development, 0.1-10 mass% tetramethyl ammonium hydroxide (TMAH) aqueous solution is mentioned, for example.

  The development processing can be carried out by a known development method, for example, a method of immersing the support in a developer for a fixed time (dip method), a developer is raised on the surface of the support by surface tension and rested for a fixed time Method (paddle method), method of spraying the developer on the surface of the support (spray method), coating the developer while scanning the developer coating nozzle at a constant speed on the support rotating at a constant speed The following method (dynamic dispensing method) and the like can be mentioned.

  The rinse process (washing process) using the rinse liquid can be implemented by the well-known rinse method. The method includes, for example, a method of continuously applying a rinse solution on a support rotating at a constant speed (rotation coating method), a method of immersing a support in a rinse solution for a certain time (dip method), a support surface And a method of spraying a rinse liquid (spray method).

[Step B]
In step B, a solution containing an acid or a thermal acid generator is applied on the support on which the first resist pattern is formed to cover the first resist pattern, and the first resist is coated. A structure comprising a pattern and a first layer covering the pattern is obtained.
In step B, a first layer formed by applying a solution containing an acid or a thermal acid generator is formed to be in contact with the pattern surface of the first resist pattern. Thereby, the solubility with respect to the developing solution of the pattern surface of a 1st resist pattern can be changed by the process C of subsequent.
In addition, the first layer formed by applying a solution containing an acid or a thermal acid generator exhibits solubility in an organic solvent used for organic solvent development.
The coating film thickness of the first layer is set to such an extent that the solubility of the upper surface of the first resist pattern in the organic solvent is not changed. The applied film thickness of the first layer is, for example, preferably 0.5 to 1.5, more preferably 0.8 to 1.4, and more preferably 0 to 1.5 relative to the pattern height of the first resist pattern. 9 to 1.2 are particularly preferred.
The solution containing the acid or thermal acid generator used in step B will be described later.

[Step C]
In step C, the structure is heated, and the solubility of the first resist pattern in an organic solvent is changed by the action of the acid or the acid generated from the thermal acid generator. The heat treatment in the step C may be, for example, baking treatment at 90 to 150 ° C. for 50 to 120 seconds.

By the step C, as shown in FIG. 1C, the solubility of the surface of the first resist pattern in the organic solvent is changed to form an organic solvent insoluble region 1Pa.
In the step A, the first resist pattern 1P is formed by alkaline development using a positive resist composition. That is, the first resist pattern is alkali insoluble.
In the step C, by heating the structure including the first resist pattern obtained in the steps A to B, an acid or an acid generated from a thermal acid generator is formed on the surface of the first resist pattern 1P. By acting on the base component (A), an organic solvent insoluble region 1 Pa in which the solubility in the organic solvent is reduced is formed. That is, the outside of the first resist pattern 1P is an insoluble region 1Pa with respect to the organic solvent, and the inside is a soluble region 1Pb with respect to the organic solvent.

In FIG. 1C, the width (line width) of the organic solvent insoluble region 1Pa or the width (space width) of the organic solvent soluble region 1Pb corresponds to each composition (base component (A) of the positive resist composition used, The acid generator component can be controlled by the acid strength of the acid or acid generated from the thermal acid generator, the heating condition in the subsequent step D, and the like.
In addition, the pKa of the acid used in step C or the acid generated from the thermal acid generator, and the pKa of the acid contained in the acid diffusion control agent contained in the positive resist composition used to form the first resist pattern When the difference of is large, it is possible to form a split pattern having a narrow line width. Here, the line width of the split pattern refers to the width of the organic solvent insoluble region 1 Pa in the cross section of FIG. 1 (D).

[Step D]
Step D is a step of forming the split pattern by developing the heated structural body with an organic solvent and removing the region other than the region in which the solubility of the first resist pattern in the organic solvent has changed. In step D, the organic solvent insoluble region 1 Pb and the first layer 2 are removed by organic solvent development.
Thereby, a split pattern finer than the first resist pattern can be formed.
FIG. 1D shows the case where a split pattern of about 1: 1: 1 line: space: line is formed.

〔Organic solvent〕
The organic solvent used for development may be any solvent as long as it can dissolve the first layer 2, the developer soluble region 1Pb and a layer B1 containing an acid diffusion control agent described later, and can be appropriately selected from known organic solvents. it can. Specifically, ketone solvents, ester solvents, nitrile solvents and the like can be mentioned. As an ester solvent, butyl acetate is preferable. As a ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

  The ketone solvent is an organic solvent containing C—C (= O) —C in the structure. An ester solvent is an organic solvent which contains C-C (= O) -O-C in a structure. The alcohol-based solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and the "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. An amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure. Among organic solvents, an organic solvent containing a plurality of functional groups characterizing each of the above-mentioned solvents in the structure is also present, in which case it corresponds to any solvent type containing a functional group possessed by the organic solvent. It shall be. For example, diethylene glycol monomethyl ether is considered to correspond to both alcohol solvents and ether solvents in the above classification. The hydrocarbon-based solvent is a hydrocarbon solvent which is composed of hydrocarbons and does not have a substituent (a hydrogen atom and a group or atom other than a hydrocarbon group).

  Specific examples of each solvent include, as ketone solvents, for example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, Methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2- Heptanone) and the like.

  As ester solvents, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono acid Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene Recall monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-Methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Nthyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyruvine Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate And ethyl acid, methyl 3-methoxy propionate, ethyl 3-methoxy propionate, ethyl 3-ethoxy propionate, propyl 3-methoxy propionate and the like.

Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitryl and the like.
A known surfactant can be added as an additive to the organic developer as needed.

  The development processing using an organic developer can be carried out by a known development method, for example, a method of immersing a support in a developer for a certain time (dip method), surface tension of the developer on the support surface Method to raise up and stand still for a fixed time (paddle method), method to spray developer on the surface of support (spray method), scanning developer coating nozzle at constant speed on support rotating at constant speed The method (dynamic dispensing method) of continuing to paint a developing solution etc. are mentioned.

After the development processing, prior to drying, a rinse treatment can be performed using a rinse solution containing an organic solvent. By performing the rinse, a good pattern can be formed.
As the organic solvent used for the rinse solution, among the solvents mentioned as the organic solvent used for the development, for example, those which do not easily dissolve the resist pattern can be appropriately selected and used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is More preferred are alcohol solvents.
The alcohol solvent used for the rinse solution is preferably a C 6-8 monohydric alcohol, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol etc. Be Among these, 1-hexanol, 2-heptanol and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
One of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use with the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and 3% by mass or less. Is particularly preferred.
Known additives can be blended into the organic developer as required. Examples of the additive include surfactants. Examples of the surfactant include the same as those described above, preferably a nonionic surfactant, and more preferably a fluorine-based surfactant or a silicon-based surfactant.
When mix | blending surfactant, the compounding quantity is normally 0.001-5 mass% with respect to the whole quantity of rinse solution, 0.005-2 mass% is preferable, and 0.01-0.5 mass is preferable. % Is more preferable.
A rinse treatment (washing treatment) using a rinse solution can be carried out by a known rinse method, for example, a method of continuously applying a rinse solution onto a support rotating at a constant speed (rotation coating method), A method of immersing the support in the rinse solution for a certain time (dip method), a method of spraying the rinse solution on the surface of the support (spray method) and the like can be mentioned.

  According to the resist pattern forming method of the first embodiment, it is possible to form a second resist pattern (split pattern) obtained by dividing (splitting) the first resist pattern.

In the resist pattern formation method of the first embodiment, the acid diffusion controlling agent component contained in the positive resist composition used to form the first resist pattern formed in step A has an acid dissociation constant of 3.0. By including the above-mentioned acid, it is thought that it can contribute to refinement of the split pattern formed in step D, reduction of LWR, and the like.
In addition, since excessive deprotection can be suppressed on the surface of the first resist pattern, it is considered that it can contribute to miniaturization of the split pattern formed in step D, reduction of LWR, and the like.

Second Embodiment
FIG. 2 shows a schematic step of the resist pattern forming method of the second embodiment. 2A to 2D show cross sections, respectively. In this embodiment, the composition contains an acid diffusion control agent containing an acid having an acid dissociation constant (pKa) of 3.0 or more, and a base component (A) whose solubility in an alkali developer is increased by the action of the acid. Positive resist compositions have been used.
First, as shown in FIG. 2A, a resist pattern 1P of line and space is formed on the support 1 using the positive resist composition (step A).
Next, as shown in FIG. 2B, a solution containing an acid or a thermal acid generator is applied so as to cover resist pattern 1P, and a first layer covering first resist pattern 1P and this. The structure 3 which consists of 2 is obtained (process B).
Next, as shown in FIG. 2 (B1), a solution containing an acid diffusion control agent is applied so as to cover the structure 3 including the first resist pattern 1P and the first layer 2 covering the first resist pattern 1P. . As a result, as shown in FIG. 2 (B1), a layer B1 containing an acid diffusion control agent is formed on the structure 3.
Thereafter, the structure 3 and the layer B1 containing an acid diffusion control agent are heated to change the solubility of the surface of the first resist pattern 1P in the organic solvent as shown in FIG. 1 (C).
Thereafter, organic solvent development is performed, and the portion shown by 1Pb in FIG. 2C is removed, whereby the first resist pattern is divided into lines, spaces, and lines as shown in FIG. ), And a fine pattern (sometimes referred to as "split pattern") is formed (step D).

[Step (A), (B)]
The steps (A) and (B) shown in FIG. 2 can be performed by the same operations as the steps (A) and (B) in the first embodiment described above.
In the step (B) of the second embodiment, the coating thickness of the first layer is not particularly limited as long as at least a part of the first resist pattern is covered, but, for example, The pattern height is preferably 0.5 to 2.0, more preferably 0.8 to 1.6, and particularly preferably 0.9 to 1.4.

[Step B1]
The second embodiment has [Step B1] after [Step B].
Step B1 is a step of applying a solution containing an acid diffusion control agent so as to cover the first layer.
As shown in FIG. 2 (B1), a solution containing an acid diffusion control agent is applied so as to cover the structure 3 composed of the first resist pattern 1P and the first layer 2 covering the first resist pattern 1P. As a result, as shown in FIG. 2 (B1), a layer B1 containing an acid diffusion control agent is formed on the structure 3.
By forming the layer B1 containing an acid diffusion control agent, it is generated particularly from the acid or thermal acid generator contained in the first layer 2 formed in the above [Step B] on the first resist pattern 1P. The action of the acid on the base component (A) in the first resist pattern 1P is weakened. The solution containing the acid diffusion control agent is applied to cover the first layer 2 and may be mixed with a portion of the top of the first layer.

  By applying a solution containing an acid diffusion control agent to cover the first layer 2 in step B1, the first resist pattern of the acid in the first layer over the first resist pattern is applied. The acid generated from the acid or thermal acid generator in the first layer on the side of the first resist pattern can be made to act while suppressing the action on the base component (A) in 1P. Therefore, it is possible to control the solubility of the upper surface portion and the side wall portion of the first resist pattern in the developer. By this, pattern separation can be performed well, and a better split pattern can be formed.

[Step (C), (D)]
The steps (C) and (D) shown in FIG. 2 can be performed by the same operations as the steps (C) and (D) in the first embodiment described above.

  Hereinafter, each material used for the resist pattern formation method of this embodiment is demonstrated.

<Other Embodiments>
Although the case of forming a line and space pattern has been described in the first embodiment and the second embodiment, the present invention is not limited to this, and a dot pattern, a desired figure pattern, etc. are formed. It can also be done.

<Positive Resist Composition>
In Step A, the positive resist composition used to form the first resist pattern adopts a positive resist composition that generates an acid upon exposure to light and the solubility in an alkali developer increases by the action of the acid. it can.
The positive resist composition contains an acid diffusion control agent containing an acid having an acid dissociation constant of 3.0 or more.
In the following, the positive resist composition may be described as a "resist composition".

<Acid Diffusion Controller Component; (D) Component>
In the present embodiment, the “acid dissociation constant (pKa)” refers to one generally used as an index indicating the acid strength of a target substance. In the present specification, pKa is a value at a temperature condition of 25 ° C. Also, the pKa value can be determined by measurement according to a known method. In addition, calculated values using known software such as “ACD / Labs” (trade name, manufactured by Advanced Chemistry Development Co., Ltd.) can also be used.

In the present embodiment, the acid diffusion controller component preferably contains an acid having an acid dissociation constant (pKa) of 4.0 or more, more preferably 4.5 or more.
The acid dissociation constant (pKa) is preferably 10 or less, more preferably 8.0 or less.
The lower limit value and the upper limit value can be arbitrarily combined.

The component (D) acts as a quencher (acid diffusion control agent) which traps an acid.
The component (D) in the present embodiment is not particularly limited as long as it contains an acid having an acid dissociation constant (pKa) of 3.0 or more, and is a photodisintegrable base which is decomposed by exposure to lose acid diffusion controllability. It may be (D1) (hereinafter referred to as “component (D1)”), and even if it is a nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) not corresponding to the component (D1). Good.

[(D1) component]
By using the positive resist composition containing the component (D1), it is possible to improve the contrast between the exposed area and the non-exposed area when forming a resist pattern.
The component (D1) is not particularly limited as long as it is a compound which generates an acid having an acid dissociation constant (pKa) of 3.0 or more and is decomposed by exposure to lose acid diffusion controllability. A compound represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), a compound represented by the following general formula (d1-2) (hereinafter "(d1-2) component" And at least one compound selected from the group consisting of compounds represented by the following general formula (d1-3) (hereinafter referred to as "(d1-3) component").
The components (d1-1) to (d1-3) do not act as a quencher because they decompose in the exposed area and lose acid diffusion controllability (basicity), and act as a quencher in the unexposed area.

［一般式（ｄ１−１）〜（ｄ１−３）中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。ただし、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子には２つ以上のフッ素原子は結合していないものとする。Ｙｄ^１は単結合、または２価の連結基である。Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[In the general formulas (d1-1) to (d1-3), Rd ^{1 to} Rd ⁴ each independently represent a cyclic group which may have a substituent, or a chain alkyl group which may have a substituent, Or a chain-like alkenyl group which may have a substituent. However, it is assumed that two or more fluorine atoms are 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 ^{m +} is each independently an m-valent organic cation. ]

{(D1-1) ingredients}
Anion moiety In general formula (d1-1), Rd ¹ has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent It may be a chain-like alkenyl group, and examples thereof include the same as R ¹⁰¹ .
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A chain hydrocarbon group is preferable, and an aromatic hydrocarbon group which may have a substituent or an aliphatic cyclic group which may have a substituent is more preferable. As a substituent which these groups may have, a hydroxyl group, an oxygen atom, a fluorine atom or a fluorinated alkyl group is preferable.
The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.
The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.
As the chain hydrocarbon group, a chain alkyl group is preferable. The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and nonyl groups. Groups, linear alkyl groups such as decyl, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl And branched alkyl groups such as 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

When the chained alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the carbon number of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and 1 The fluorinated alkyl group of which -4 is more preferably may contain an atom other than a fluorine atom. As an atom other than a fluorine atom, an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom etc. are mentioned, for example.
Rd ¹ is preferably a fluorinated alkyl group in which a part or all of the hydrogen atoms constituting the linear alkyl group are substituted by a fluorine atom, and one of the hydrogen atoms constituting the linear alkyl group is preferred. It is preferable that they are all fluorinated alkyl groups (linear perfluoroalkyl groups) substituted with a fluorine atom.

  The preferable specific example of the anion part of a (d1-1) component is shown below. Moreover, the acid dissociation constant (pKa) of the acid generated from the compound which has the following anions is described collectively.

-Cation part In general formula (d1-1), Mm ⁺ is a m-valent organic cation.
The organic cation of M ^{m +} is not particularly limited, and examples thereof include the same ones as the cations represented by the general formulas (ca-1) to (ca-4), respectively, and The cation represented by 1) to (ca-1-63) is preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) ingredients}
Anion part In general formula (d1-2), Rd ² has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent. And an optionally substituted chain-like alkenyl group, and examples thereof include the same as R ¹⁰¹ .
However, two or more fluorine atoms are not bonded to carbon atoms 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 quenching ability of the component (D) is improved.
Rd ² is preferably an aliphatic cyclic group which may have a substituent, and is a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane or the like It is more preferable that it is a group obtained by removing one or more hydrogen atoms from camphor or the like.
The hydrocarbon group of Rd ² may have a substituent, and as the substituent, a hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the above formula (d1-1) can be mentioned The same as the substituent which may have is mentioned.

  The preferable specific example of the anion part of (d1-2) component is shown below. The acid dissociation constant (pKa) of the acid generated from the compound having the following anion is -1.0 to 10.0.

-Cation part In general formula (d1-2), Mm ⁺ is a m-valent organic cation, and is the same as Mm ⁺ in the said general formula (d1-1).
As the component (d1-2), one type may be used alone, or two or more types may be used in combination.

{(D1-3) ingredients}
Anion part In the general formula (d1-3), Rd ³ has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent It may be a chained alkenyl group which may be the same as R ^101, and is preferably a fluorine atom-containing cyclic group, a chained alkyl group or a chained alkenyl group. Among them, a fluorinated alkyl group is preferable, and the same fluorinated alkyl group as Rd ¹ is more preferable.

In General Formula (d1-3), Rd ⁴ may be a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A good chained alkenyl group, including the same as R ¹⁰¹ .
Among them, an alkyl group which may have a substituent, an alkoxy group, an alkenyl group and a cyclic group are preferable.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group And tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with 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 as the alkoxy group having 1 to 5 carbon atoms, specifically, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, n- Examples include butoxy and tert-butoxy. Among these, methoxy and ethoxy are preferable.

The alkenyl group in Rd ⁴ includes the same ones as the above-mentioned R ^101, and a vinyl group, propenyl group (allyl group), 1-methylpropenyl group and 2-methylpropenyl group are preferable. These groups may further have an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms as a substituent.

Examples of the cyclic group for Rd ⁴ include the same as the above R ^101, and one or more hydrogen atoms are removed from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. Preferred is an alicyclic group, or an aromatic group such as a phenyl group or a naphthyl group. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in the organic solvent, whereby the lithography properties are improved. In addition, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics become good.

In general formula (d1-3), Yd ¹ is a single bond or a divalent linking group.
The divalent linking group in Y d ¹ is not particularly limited, and may be a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a hetero atom And the like. Each of which include the same ones as exemplified in the description of the divalent linking group for Ya ²¹ in the general formula (a2-1).
As Yd ¹ , a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof is preferable. The alkylene group is more preferably a linear or branched alkylene group, and still more preferably a methylene group or an ethylene group.

  The preferable specific example of the anion part of (d1-3) component is shown below. The acid dissociation constant (pKa) of the acid generated from the compound having the following anion is 3.0 to 10.0.

-Cation part In general formula (d1-3), Mm ⁺ is a m-valent organic cation, and is the same as Mm ⁺ in the said general formula (d1-1).
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

As the component (D1), any one of the components (d1-1) to (d1-3) may be used alone, or two or more thereof may be used in combination.
In the embodiment, a compound represented by the above general formula (d1-1) or (d1-3) is preferable, and a compound represented by the above general formula (d1-3) is more preferable.
The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass with respect to 100 parts by mass of the component (A) described later. More preferably, it is 8 parts by mass.
When the content of the component (D1) is equal to or more than the preferable lower limit value, a split pattern with fine dimensions can be easily obtained. On the other hand, it can contribute to reduction of LWR of a split pattern, etc. as it is below an upper limit.

  The manufacturing method of said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.

((D2) ingredient)
The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as the component (D2)) which does not correspond to the component (D1).
The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and has an acid dissociation constant (pKa) of 3.0 or more and does not correspond to the component (D1). Any of known ones may be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines, and compounds having an acid dissociation constant (pKa) of 3.0 or more are preferable.
The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.
Examples of the aliphatic amine, at least one hydrogen atom of ammonia NH _3, amines substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (the alkyl amine or alkyl alcohol amines) or a cyclic amine.

The cyclic amine includes, for example, a heterocyclic compound containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Further, as the component (D2), an aromatic amine may be used.

The component (D2) may be used alone or in combination of two or more.
The component (D2) is used usually in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A) described later. By setting it in the above-mentioned range, the resist pattern shape, the stability over time of placing, etc. are improved.

<Other ingredients>
In the present embodiment, the positive resist composition is, in addition to the component (D), a base component (A) (hereinafter also referred to as “component (A)”) in which the solubility in an alkali developer is increased by the action of acid. .) Is used. In addition, the positive resist composition may contain optional components other than the component (D) and the component (A) as required. Examples of the optional components include an acid generator component (B) which generates an acid upon exposure, a specific compound (E), a fluorine additive (F) and the like.

  When a positive resist film is formed using such a positive resist composition and the resist film is selectively exposed, an acid is generated in the exposed area, and the action of the acid causes the alkali of the component (A) to be generated. While the solubility in the developer increases, the solubility of the component (A) in the alkali developer does not change in the unexposed area, so that the solubility difference in the developer between the exposed area and the unexposed area occurs . Therefore, when the resist film is subjected to alkali development, the exposed portion is dissolved and removed to form a positive resist pattern. This positive resist pattern is soluble in organic solvents.

In the present embodiment, the positive resist composition has an acid generating ability to generate an acid upon exposure, and the component (A) may generate an acid upon exposure, and the component is blended separately from the component (A). The added additive components may generate an acid upon exposure.
Specifically, in the present embodiment, the positive resist composition is
(1) may contain an acid generator component (B) (hereinafter referred to as "component (B)") which generates an acid upon exposure to light;
(2) The component (A) may be a component that generates an acid upon exposure to light;
(3) The component (A) may be a component that generates an acid upon exposure to light, and may further contain a component (B).
That is, in the case of the above (2) and (3), the component (A) becomes "a base component which generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid". When the component (A) is a base component which generates an acid upon exposure and the solubility in a developer increases by the action of the acid, the component (A1) described later generates an acid upon exposure, and It is preferable that it is a polymer compound whose solubility in a developer increases by the action of an acid. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. Known structural units can be used as structural units that generate an acid upon exposure.
In the present embodiment, the positive resist composition is particularly preferably the case of the above (1).

<(A) component>
In the present embodiment, the “base component” is an organic compound having a film forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, it is easy to form a nano-level photosensitive resin pattern.
Organic compounds used as a base component are roughly classified into non-polymers and polymers.
As the non-polymer, one having a molecular weight of 500 or more and less than 4,000 is usually used. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4,000.
As the polymer, one having a molecular weight of 1,000 or more is usually used. Hereinafter, the term "resin" refers to a polymer having a molecular weight of 1000 or more.
As a molecular weight of a polymer, the weight average molecular weight of polystyrene conversion by GPC (gel permeation chromatography) shall be used.
As the component (A), a resin may be used, a low molecular weight compound may be used, and these may be used in combination.
The component (A) is such that the solubility in an alkali developer is increased by the action of an acid.
In the present embodiment, the component (A) may generate an acid upon exposure.

In the present embodiment, the component (A) preferably contains a polymer compound (A1) whose solubility in an alkaline developer is increased by the action of an acid. It is preferable that the polymer compound (A1) has a structural unit containing an acid-degradable group whose polarity is increased by the action of an acid (hereinafter sometimes referred to as “structural unit (a1)”).
In addition to the structural unit (a1), the polymer compound (A1) has a —SO ₂ — containing cyclic group, a lactone containing cyclic group, a carbonate containing cyclic group, or a heterocyclic group other than these. It is preferable to have a unit (Hereinafter, it may be called "constituent unit (a2).").

(Constituent unit (a1))
The structural unit (a1) is a structural unit containing an acid-degradable group whose polarity is increased by the action of an acid.
The "acid-degradable group" is a group having acid-degradability which can cleave at least a part of bonds in the structure of the acid-degradable group by the action of an acid.
Examples of the acid-degradable group whose polarity is increased by the action of an acid include, for example, a group which is decomposed by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group _(-SO 3 H) and the like. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-degradable group include groups in which the polar group is protected by an acid dissociative group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid dissociative group).
Here, the "acid dissociable group" is
(I) A group having an acid dissociability that can cleave the bond between the acid dissociable group and the atom adjacent to the acid dissociable group by the action of an acid, or
(Ii) A group capable of cleaving a bond between the acid dissociable group and an atom adjacent to the acid dissociable group by further causing a decarboxylation reaction after partial bond cleavage is caused by the action of an acid ,
Say both sides.
The acid dissociable group constituting the acid decomposable group is required to be a group having a polarity lower than that of the polar group generated by the dissociation of the acid dissociable group, whereby the acid dissociable group is formed by the action of an acid. When dissociates, a polar group having a polarity higher than that of the acid-dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) is increased. As the polarity increases, the solubility in the developer relatively changes, and when the developer is an organic developer, the solubility decreases.

The acid dissociable group is not particularly limited, and those which have been proposed as acid dissociable groups of base resins for chemically amplified resists can be used.
Among the above polar groups, as an acid dissociable group for protecting a carboxy group or a hydroxyl group, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal type acid dissociable Group) may be mentioned.

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基、Ｒａ’^３は炭化水素基、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。＊は結合手を意味する。］

[Wherein, Ra ′ ¹ and Ra ′ ² are a hydrogen atom or an alkyl group, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ is bonded to any of Ra ′ ¹ and Ra ′ ² to form a ring Good. * Means a bond. ]

In the general formula (a1-r-1), examples of the alkyl group of Ra ′ ¹ and Ra ′ ² include, as a substituent which may be bonded to the carbon atom at the α position, in the explanation of the α-substituted acrylic acid ester. The same alkyl groups as mentioned above can be mentioned, with a methyl group or an ethyl group being preferred, and a methyl group being most preferred.

The ra ^'3 hydrocarbon group is preferably an alkyl group having 1 to 20 carbon atoms, the alkyl group is more preferably 1 to 10 carbon atoms; preferably a linear or branched alkyl group, specifically, Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group And 2,2-dimethylpropyl and 2,2-dimethylbutyl groups.

When Ra ′ ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, or may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cyclooctane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from polycycloalkane is preferable, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferable, and specifically, adamantane , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When it becomes an aromatic hydrocarbon group, specifically, an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene or the like as the contained aromatic ring; carbon atoms constituting the aromatic hydrocarbon ring And aromatic heterocycles partially substituted with heteroatoms; and the like. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, as the aromatic hydrocarbon group, a group (aryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring; a group in which one hydrogen atom of the aryl group is substituted with an alkylene group (for example, And arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc .; and the like. The carbon number of the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

When Ra ′ ³ combines with 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 tetrahydropyranyl group, tetrahydrofuranyl group and the like.

  As an acid dissociative group which protects a carboxy group among the said polar groups, the acid dissociative group represented by the following general formula (a1-r-2) is mentioned, for example (following formula (a1-r-2) Among the acid dissociable groups represented by), those composed of alkyl groups are hereinafter sometimes referred to as "tertiary alkyl ester type acid dissociable groups" for convenience.

［一般式（ａ１−ｒ−２）中、Ｒａ’^４〜Ｒａ’^６は炭化水素基であり、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。＊は結合手を意味する。］

[In formula (a1-r-2), Ra '4 ~Ra' 6 is a hydrocarbon group, Ra ^'5, Ra' ⁶ may be bonded to each other to form a ring. * Means a bond. ]

Examples of the hydrocarbon group Ra ^'4 ~Ra' ⁶ include the same as the Ra ^'3. Ra ^'4 is preferably an alkyl group having 1 to 5 carbon atoms. When Ra ′ ⁵ and Ra ′ ⁶ bond to each other to form a ring, groups represented by general formula (a1-r2-1) shown below can be mentioned.
On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by general formula (a1-r2-2) shown below can be mentioned.

［一般式（ａ１−ｒ２−１）又は（ａ１−ｒ２−２）中、Ｒａ’^１０は炭素数１〜１０のアルキル基、Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基、Ｒａ’^１２〜Ｒａ’^１４は、それぞれ独立に炭化水素基を示す。＊は結合手を意味する。］

[Formula (a1-r2-1) or in (a1-r2-2), Ra ' 10 is an alkyl group having 1 to 10 carbon atoms, Ra' ¹¹ aliphatic cyclic together with the carbon atom to which Ra ^'10 is bonded The group which forms a group, and Ra ′ ^{12 to} Ra ′ ¹⁴ each independently represent a hydrocarbon group. * Means a bond. ]

In the general formula (a1-r2-1), the alkyl group of the alkyl group having 1 to ¹⁰ carbon atoms of Ra′10 is a linear or branched form of Ra ′ ³ in the general formula (a1-r-1) The groups mentioned as the alkyl group are preferred. In the general formula (a1-r2-1), the aliphatic cyclic group formed by Ra ′ ¹¹ is preferably the group mentioned as the cyclic alkyl group of Ra ′ ³ in the general formula (a1-r-1).

In the formula (a1-r2-2), it is preferable that Ra is ^'12 and Ra' ¹⁴ each independently represents an alkyl group having 1 to 10 carbon atoms, the alkyl group, the general formula (a1-r-1) The group mentioned as the linear or branched alkyl group of Ra ′ ^{3 in} the above is more preferable, the linear alkyl group having 1 to 5 carbon atoms is more preferable, and a methyl group or an ethyl group is more preferable. Particularly preferred.
In the general formula (a1-r2-2), Ra ′ ¹³ is a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group of Ra ′ ³ in the general formula (a1-r-1) Is preferred. Among these, the groups mentioned as the cyclic alkyl group of Ra ′ ³ are more preferable.

  Specific examples of the group represented by the general formula (a1-r2-1) will be given below. In the following formulas, "*" indicates a bond.

  Specific examples of the group represented by the general formula (a1-r2-2) will be given below.

  Moreover, as an acid dissociable group which protects a hydroxyl group among the said polar groups, the acid dissociable group represented by the following general formula (a1-r-3) (hereinafter, for convenience, “tertiary alkyloxycarbonyl acid” Sometimes referred to as "dissociable group".

［一般式（ａ１−ｒ−３）中、Ｒａ’^７〜Ｒａ’^９はアルキル基を示す。＊は結合手を意味する。］

[In the formula (a1-r-3), Ra '7 ~Ra' 9 is an alkyl group. * Means a bond. ]

In the formula (a1-r-3), Ra '7 ~Ra' 9 is preferably an alkyl group having 1 to 5 carbon atoms, 1 to 3 is more preferable.
Further, the total carbon number of each alkyl group is preferably 3 to 7, more preferably 3 to 5 and most preferably 3 to 4.

  The structural unit (a1) is a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and an acid whose polarity is increased by the action of an acid. Structural units containing degradable groups; Structural units in which at least a part of hydrogen atoms in the hydroxyl groups of structural units derived from hydroxystyrene or hydroxystyrene derivatives are protected by a substituent containing the acid decomposable group; vinylbenzoic acid or The structural unit etc. with which at least one copy of the hydrogen atom in -C (= O) -OH of the structural unit derived from a vinyl benzoic acid derivative was protected by the substituent containing the said acid-degradable group etc. are mentioned.

Among the above, as the structural unit (a1), a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent is preferable.
As the structural unit (a1), structural units represented by general formula (a1-1) or (a1-2) shown below are preferable.

［一般式（ａ１−１）又は（ａ１−２）中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１はエーテル結合、ウレタン結合、又はアミド結合を有していてもよい２価の炭化水素基であり、ｎ_ａ１は０〜２であり、Ｒａ^１は上記一般式（ａ１−ｒ−１）〜（ａ１−ｒ−２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３であり、Ｒａ^２は上記一般式（ａ１−ｒ−１）または（ａ１−ｒ−３）で表される酸解離性基である。］

[In general formula (a1-1) or (a1-2), R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ¹ is a divalent hydrocarbon group which may have an ether bond, a urethane bond or an amide bond, n _a1 is 0 to 2 and Ra ¹ is the above general formula (a1-r-1) It is an acid dissociative group represented by-(a1-r-2). Wa ¹ is an n _a2 + 1-valent hydrocarbon group, n _a2 is 1 to 3, and Ra ² is an acid dissociation represented by the above general formula (a1-r-1) or (a1-r-3) It is a sex group. ]

In the general formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, A propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like can be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are 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 of 1 to 5 carbon atoms, or a fluorinated alkyl group of 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable in terms of industrial availability.
The hydrocarbon group of Va ¹ 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 bivalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specifically, as the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like can be mentioned.
Further, Va ¹ includes ^{one in which the} divalent hydrocarbon group is 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, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
As a linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 - ; alkylethylene groups such as - _{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 An alkylethylene group such as CH ₃ ) ₂ -CH _2- ; an alkyltrimethylene group such as -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH _2- ; -CH (CH ₃ ) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. As an alkyl group in an alkyl alkylene group, a C1-C5 linear alkyl group is preferable.

As an aliphatic hydrocarbon group which contains a ring in the said structure, alicyclic hydrocarbon group (The group which remove | eliminated two hydrogen atoms from the aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group are linear or branched Examples thereof include a group bonded to the end of a linear aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferable, and specifically, adamantane , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, and still more preferably 5 to 20 carbon atoms. 15 is particularly preferred, and 6 to 10 is most preferred. However, the carbon number does not include the carbon number in the substituent.
Specifically as an aromatic ring which an aromatic hydrocarbon group has, aromatic hydrocarbon rings, such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene etc; some carbon atoms which comprise the said aromatic hydrocarbon ring are hetero And aromatic hetero rings substituted by atoms; and the like. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, as the aromatic hydrocarbon group, a group in which two hydrogen atoms are removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom is removed from the aromatic hydrocarbon ring (aryl group And arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group etc. And the like. Groups in which one hydrogen atom is further removed from the aryl group in the group) and the like. The carbon number of the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the general formula (a1-2), the n _a2 + 1-valent hydrocarbon group 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, which may be saturated or unsaturated, and is preferably saturated. As the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group The group which combined the aliphatic hydrocarbon group which contains a ring in a structure is mentioned, The same group as Va ¹ of the above-mentioned general formula (a1-1) is mentioned specifically ,.
The n _a2 +1 valence is preferably 2 to 4 and more preferably 2 or 3.

  As the structural unit represented by General Formula (a1-2), a structural unit represented by General Formula (a1-2-01) shown below is particularly preferable.

In the general formula (a1-2-01), Ra ² is an acid dissociable group represented by the general formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. R is as defined above.
Hereinafter, specific examples of the structural unit represented by General Formula (a1-1) or (a1-2) will be shown. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  The proportion of the structural unit (a1) in the component (A) is preferably 20 to 80 mol%, more preferably 20 to 75 mol%, and 25 to 70 mol% with respect to all the structural units constituting the component (A). Is more preferred. By setting the lower limit value or more, lithography properties such as sensitivity, resolution and LWR are also improved. Further, by setting the upper limit value or less, it is possible to balance with other constituent units.

(Constituent unit (a2))
The structural unit (a2) is a structural unit having a —SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group or a heterocyclic group other than these.
In the structural unit (a2), the —SO ₂ -containing cyclic group, the lactone-containing cyclic group, the carbonate-containing cyclic group or the heterocyclic group other than these is used when the component (A) is used to form a resist film. And is effective in enhancing the adhesion of the resist film to the substrate.
In addition, when the above-mentioned structural unit (a1) contains in the structure thereof a —SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group or a heterocyclic group other than these, the structural unit The above corresponds to the structural unit (a2), but such a structural unit corresponds to the structural unit (a1) 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).

［一般式（ａ２−１）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｙａ^２１は単結合または２価の連結基であり、Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１は−ＳＯ_２−含有環式基、ラクトン含有環式基、カーボネート含有環式基又はこれら以外の複素環式基である。］

[In the general formula (a2-1), R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms, or a halogenated alkyl group of 1 to 5 carbon atoms, and Ya ²¹ represents a single bond or a divalent linking group And La ²¹ is -O-, -COO-, -CON (R ')-, -OCO-, -CONHCO- or -CONHCS-, and R' is a hydrogen atom or a methyl group. However, when La ²¹ is —O—, Ya ²¹ does not become —CO—. Ra ²¹ is a —SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group or a heterocyclic group other than these. ]

The divalent linking group for Ya ²¹ is not particularly limited, and preferred examples thereof include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

The hydrocarbon group as a divalent linking group which may have a substituent 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, and specifically, the above-mentioned general formula (a1) Groups exemplified for Va ¹ in -1) can be mentioned.

  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 of 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

As the aliphatic hydrocarbon group containing a ring in the above structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (2 hydrogen atoms are removed from an aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched fatty acid And the like interposed in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group, specifically include groups exemplified in Va ¹ in the above general 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, a carbonyl group and the like.
The alkyl group as the substituent is preferably an alkyl group having a carbon number of 1 to 5, 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 a carbon number of 1 to 5, and is preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, methoxy And ethoxy groups are most preferred.
As a halogen atom as the said substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
As a halogenated alkyl group as said substituent, the group by which one part or all part of the hydrogen atom of the said alkyl group was substituted by the said halogen atom is mentioned.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. The substituent containing a hetero atom, -O -, - C (= O) -O -, - S -, - S (= O) 2 -, - S (= O) 2 -O- are preferred.

Examples of the divalent aromatic hydrocarbon group as the hydrocarbon group, specifically include exemplified groups Va ¹ in the above general formula (a1-1).
In the aromatic hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted by a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted by a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group and the like.
The alkyl group as the substituent is preferably an alkyl group having a carbon number of 1 to 5, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
As the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent, those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group can be mentioned.

The hetero atom in the bivalent linking group containing hetero atom The hetero atom in the bivalent linking group containing hetero atom is atoms other than a carbon atom and a hydrogen atom, for example, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom etc. are mentioned. Be

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred as the linking group are —O—, —C (= O) —O—, —C (= O) —, —O—C. (= O) -O-, -C (= O) -NH-, -NH-, -NH-C (= NH)-(H may be substituted with a substituent such as an alkyl group or an acyl group _{.), - S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - C (= O) -O -, - C (= O) -O - Y 21, [Y 21 -C (= O) -O] m '-Y 22 - or ^-Y 21 -O-C (= A group represented by the formula O) -Y ^22-wherein Y ²¹ and Y ²² each independently represent a divalent hydrocarbon group which may have a substituent, and O is an oxygen atom, m 'is an integer of 0-3. Etc.
When the divalent linking group containing a hetero atom is —C (= O) —NH—, —NH—, —NH—C (= NH) —, H is a substituent such as an alkyl group or acyl. It may be substituted. The substituent (such as an alkyl group or an acyl group) 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 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21, - [Y 21 -C ( _{= O) -O] m '-Y} 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{in, Y 21} and ^{Y 22} each independently have a substituent It is a good bivalent hydrocarbon group. As this bivalent hydrocarbon group, the thing similar to "the bivalent hydrocarbon group which may have a substituent" mentioned by the description as said bivalent coupling group is mentioned.
As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group of 1 to 5 carbon atoms, more preferably a linear alkyl group of 1 to 3 carbon atoms, and most preferably a methyl group.
Formula ^{- [Y 21 -C (= O} ) -O] m '-Y 22 - In the group represented by, m' is an integer of 0 to 3, preferably an integer of 0 to 2, 0 Or 1 is more preferable, and 1 is particularly preferable. In other words, the formula ^- Examples of the group represented by the formula ^{-Y 21 -C (= O) -O} -Y 22 - - [Y 21 -C (= O) -O] m '-Y 22 represented by Groups are particularly preferred. Among them, the formula _{- (CH 2) a '-C} (= O) -O- (CH 2) b' - a group represented by are preferred. 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, still 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, still more preferably 1 or 2, and most preferably 1.

In this embodiment, Ya ²¹ is a single bond, or an ester bond [-C (= O) -O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof Is preferred.

In the general formula (a2-1), Ra ²¹ is a —SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group or a heterocyclic group other than these.

And _- "-SO 2 containing cyclic group", -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO 2 _- sulfur atom (S) is in It is a cyclic group that forms a part of the ring skeleton of the cyclic group. The ring containing -SO _{2-in the} ring skeleton is counted as the first ring, and in the case of only this ring, it is a monocyclic group, and in the case of having another ring structure, a polycyclic group regardless of its structure It is called. The —SO ₂ -containing cyclic group may be monocyclic or polycyclic.
The -SO ₂ -containing cyclic group is, in particular, a cyclic group containing -O-SO ₂ -in its ring skeleton, ie -O-S- in -O-SO ₂ -is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed. More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子またはアルキル基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｎ’は０〜２の整数である。］

[Wherein, each of Ra ^'51 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano group R ′ ′ is a hydrogen atom or an alkyl group; A ′ ′ is an oxygen atom or an alkylene group having 1 to 5 carbon atoms which may contain a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is 0 to 2 Is an integer of ]

In the general formulas (a5-r-1) to (a5-r-4), A ′ ′ is the same as A ′ ′ in general formulas (a2-r-1) to (a2-r-7) described later. . Alkyl group in ra ^'51, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR ", - OC (= O) R", The hydroxyalkyl group, described below general formula (a2-r-1) ~ ( is the same as a2-r-7) in the Ra ^'21.

  Specific examples of the groups represented by general formulas (a5-r-1) to (a5-r-4) will be given below. "Ac" in a formula shows an acetyl group.

In the embodiment, when the structural unit (a2) contains a —SO ₂ — containing cyclic group, among the above, the group represented by the general formula (a5-r-1) is preferable, and the chemical formula (r− selected from the group consisting of a group represented by any of sl-1-1), (r-sl-1-18), (r-sl-3-1) and (r-sl-4-1); It is more preferable to use at least one of them, and the group represented by the chemical formula (r-sl-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 ring skeleton thereof. The lactone ring is counted as the first ring, and when it has only a lactone ring, it is a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone-containing cyclic group is not particularly limited, and any group can be used. Specifically, groups represented by general formulas (a2-r-1) to (a2-r-7) shown below can be mentioned. Hereinafter, "*" represents a bond.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子またはアルキル基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｎ’は０〜２の整数であり、ｍ’は０または１である。］

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

In the general formulas (a2-r-1) to (a2-r-7), A ′ ′ is an oxygen atom (—O—) or a sulfur atom (—S—) and may have 1 to 5 carbon atoms As the alkylene group having 1 to 5 carbon atoms in A ′ ′, a linear or branched alkylene group is preferable, and a methylene group, an ethylene group, an n-propylene group, An isopropylene group etc. are mentioned. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— intervenes in the terminal of the alkylene group or between carbon atoms, such as —O—CH _{2 -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like. As A ′ ′, an alkylene group of 1 to 5 carbon atoms or —O— is preferable, an alkylene group of 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable. Ra ′ ²¹ is each independently an alkyl group or alkoxy A halogen atom, a halogenated alkyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano group.
The alkyl group in ra ^'21, preferably an alkyl group having 1 to 5 carbon atoms.
The alkoxy group in the ra ^'21, preferably an alkoxy group having 1 to 6 carbon atoms.
The alkoxy group is preferably linear or branched. Specifically, groups of the the Ra 'group and an oxygen atom mentioned as the alkyl group in ²¹ (-O-) are linked and the like.
As the halogen atom in ra ^'21, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom is preferable.
'Examples of the halogenated alkyl group for ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. The halogenated alkyl group is preferably a fluorinated alkyl group, particularly preferably a perfluoroalkyl group.
R ′ ′ is a hydrogen atom or an alkyl group, and the alkyl group of R ′ ′ is preferably an alkyl group having 1 to 5 carbon atoms.

  Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) will be given below.

  In the embodiment, the structural unit (a2) is preferably a group represented by the general formula (a2-r-1) or (a2-r-2), respectively, and the chemical formula (r-lc-1-1) Or a group represented by (r-lc-2-7) is more preferable.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (−O) —O— in its ring skeleton. The carbonate ring is counted as the first ring, and in the case of only the carbonate ring, it is a monocyclic group, and when it has another ring structure, it is referred to as a polycyclic group regardless of its structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
The carbonate ring-containing cyclic group is not particularly limited, and any group can be used. Specifically, groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) can be mentioned.

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子またはアルキル基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子でありｑ’は０または１である。ｐ’は、０〜３の整数である。］

[ ^Wherein , each of Ra ' ^{x 31} independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano group R ′ ′ is a hydrogen atom or an alkyl group; A ′ ′ is an oxygen atom or an alkylene group having 1 to 5 carbon atoms which may contain a sulfur atom, an oxygen atom or a sulfur atom, and q ′ is 0 or 1 is there. p 'is an integer of 0-3. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ′ ′ is the same as A ′ ′ in the general formula (a2-r-1).
Alkyl group in ra ^'31, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR ", - OC (= O) R", The hydroxyalkyl group, each of the general formulas (a2-r-1) ~ ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.

  Specific examples of the groups represented by formulas (ax3-r-1) to (ax3-r-3) will be given below.

  The "heterocyclic group" other than the above refers to a cyclic group containing one or more atoms other than carbon in addition to carbon, and the chemical formulas (r-hr-1) to (r-hr-16) described later And heterocyclic groups, nitrogen-containing heterocyclic groups, etc. The nitrogen-containing heterocyclic group includes a cycloalkyl group having 3 to 8 carbon atoms which may be substituted by one or two oxo groups. Preferred examples of the nitrogen-containing cycloalkyl group include 2,5-dioxopyrrolidine and a group in which one or more hydrogen atoms have been removed from 2,6-dioxopiperidine.

The structural unit (a2) of the component (A) may be of one type or of two or more types.
When the component (A) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% with respect to the total of all structural units constituting the component (A), The content is more preferably 5 to 70 mol%, further preferably 10 to 65 mol%, and particularly preferably 10 to 60 mol%. By setting the content to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the content to the upper limit value or less, balance with other structural units can be achieved, and various lithography properties and patterns are obtained. The shape is good.

  The component (A1) may have the following structural unit (a3) and the structural unit (a4) in addition to the structural units (a1) and (a2).

(Constituent unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (with the exception of those corresponding to the structural units (a1) and (a2) described above).
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is enhanced, which is considered to contribute to the improvement of the resolution.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom, with a hydroxyl group being particularly preferable.
As an aliphatic hydrocarbon group, a C1-C10 linear or branched hydrocarbon group (preferably alkylene group) and cyclic aliphatic hydrocarbon group (cyclic group) are mentioned. The cyclic group may be a monocyclic group or a polycyclic group. For example, in the resin for a resist composition for ArF excimer laser, it can be appropriately selected and used from those proposed in large numbers. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group or an alkyl group is substituted with a fluorine atom Is more preferred. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, tricycloalkane, tetracycloalkane or the like. Specific examples thereof include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane. Among these polycyclic groups, groups in which two or more hydrogen atoms are removed from adamantane, groups in which two or more hydrogen atoms are removed from norbornane, and groups in which two or more hydrogen atoms are removed from tetracyclododecane are Industrially preferred.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.
The structural unit (a3) is a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and contains a polar group-containing aliphatic hydrocarbon group Constituent units are preferred.
As the structural unit (a3), 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, it is derived from hydroxyethyl ester of acrylic acid Structural unit is preferable, and when the hydrocarbon group is a polycyclic group, a structural unit represented by the following general formula (a3-1), a structural unit represented by the general formula (a3-2), The structural unit represented by general formula (a3-3) is mentioned as a preferable thing.

［一般式（ａ３−１）〜（ａ３−３）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。］

[In general formulas (a3-1) to (a3-3), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and j is an integer of 1 to 3] K is an integer of 1 to 3, t 'is an integer of 1 to 3, l is an integer of 1 to 5, and s is an integer of 1 to 3. ]

In the general formulas (a3-1) to (a3-3), the description of R is the same as above.
In the general formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group be bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group be bonded to the 3rd position of the adamantyl group.
j is preferably 1, and particularly preferably, the hydroxyl group is bonded to the 3-position of the adamantyl group.

In the general formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.
In general formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. As for these, it is preferable that 2- norbornyl group or 3- norbornyl group is couple | bonded with the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5 or 6 position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be of one type or of two or more types.
The proportion of the structural unit (a3) in the component (A1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the resin component (A1). Preferably, 5 to 25 mol% is more preferable.
By setting the ratio of the structural unit (a3) to the lower limit value or more, an effect by containing the structural unit (a3) is sufficiently obtained, and by setting the ratio to the upper limit value or less, balance with other structural units is balanced. It will be easier.

(Constituent unit (a4))
The structural unit (a4) is a structural unit containing a non-acid dissociable cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. In addition, the hydrophobicity of the component (A1) is enhanced. The improvement of the hydrophobicity is considered to contribute to the improvement of the resolution, the resist pattern shape and the like particularly in the case of organic solvent development.
The “non-acid-dissociable cyclic group” in the structural unit (a4) is, when an acid is generated from the component (B) described later, upon exposure, it does not disassociate even if the acid acts and does not dissociate in the structural unit. It is a remaining cyclic group.
As the structural unit (a4), for example, a structural unit derived from an acrylic acid ester containing a non-acid dissociable aliphatic cyclic group is preferable. The cyclic group may be, for example, the same one as exemplified in the case of the structural unit (a1), and for an ArF excimer laser, for a KrF excimer laser (preferably for an ArF excimer laser), etc. A large number of materials conventionally known as those used for the resin component of the resist composition of the present invention can be used.
Particularly, at least one 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 any of the following general formulas (a4-1) to (a4-7).

［式（ａ４−１）〜（ａ４−７）中、Ｒ^αは、水素原子、メチル基またはトリフルオロメチル基を示す。］

[In Formula (a4-1) to (a4-7), R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. ]

The structural unit (a4) contained in the component (A1) may be of one type or of two or more types.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all structural units constituting the component (A1), It is more preferable that it is 10-20 mol%.

  The component (A1) is preferably a copolymer having (a1) and (a2).

The component (A1) is obtained by polymerizing a monomer for deriving each constitutional unit, for example, by known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. be able to.
In addition, for the component (A1), for example, a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C (CF ₃ ) ₂ -OH is used in combination at the time of the above polymerization. -C (CF ₃ ) ₂ -OH group may be introduced to Thus, a copolymer in which a hydroxyalkyl group is introduced in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom has reduced development defects and LER (line edge roughness: uneven unevenness of the line sidewall). Is effective in reducing the

  In the present embodiment, the weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion by gel permeation chromatography) is not particularly limited, 1000 to 50000 is preferable, and 1500 to 30000 is more preferable. 2000 to 20000 are most preferred. When it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is above the lower limit of this range, the dry etching resistance and the resist pattern cross-sectional shape are good.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
25 mass% or more is preferable with respect to the total mass of a base material component (A), as for the ratio of the (A1) component in a base material component (A), 50 mass% is more preferable, 75 mass% is more preferable, and 100 It may be mass%. When the proportion is 25% by mass or more, the lithography properties are further improved.

In the present embodiment, as the component (A), one type may be used alone, or two or more types may be used in combination.
In the present embodiment, the content of the component (A) may be adjusted in accordance with the thickness of the resist film to be formed.

<Acid generator component; (B) component>
In the present embodiment, the resist composition may contain an acid generator component (B) (hereinafter referred to as component (B)) which generates an acid upon exposure. The component (B) is not particularly limited, and those which have been proposed as acid generators for chemically amplified resists can be used.
Examples of such an acid generator include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and diazomethanes such as poly (bissulfonyl) diazomethanes. There are various types such as an acid generator, a nitrobenzyl sulfonate-based acid generator, an iminosulfonate-based acid generator, and a disulfone-based acid generator. Among them, it is preferable to use an onium salt-based acid generator.

  As the onium salt-based acid generator, for example, a compound represented by the following general formula (b-1) (hereinafter also referred to as “component (b-1)”), a compound represented by general formula (b-2) A compound (hereinafter also referred to as “component (b-2)”) or a compound represented by general formula (b-3) (hereinafter also referred to as “component (b-3)”) can be used.

［一般式（ｂ−１）〜（ｂ−３）中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０６〜Ｒ^１０７のいずれか２つは、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。Ｍ’^ｍ＋はｍ価の有機カチオンである。］

[In the general formulas (b-1) to (b-3), R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ may each independently have a cyclic group which may have a substituent, or a substituent] It is a chained alkyl group or a chained alkenyl group which may have a substituent. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. Any two of R ^{106 to} R ¹⁰⁷ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group of 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ^{101 to} V ¹⁰³ each independently represent a single bond, an alkylene group, or a fluorinated alkylene group. L ^{101 to} L ¹⁰² each independently represent a single bond or an oxygen atom. L ^{103 to} L ¹⁰⁵ are each independently a single bond, -CO- or -SO _2- . M ' ^{m +} is an m-valent organic cation. ]

{Anion part}
Anion part of component (b-1) In the general formula (b-1), R ¹⁰¹ is a cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent Or a chain-like alkenyl group which may have a substituent.

(Cyclic group optionally having substituent (s) for R ¹⁰¹ )
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 in R ¹⁰¹ is an aromatic compound containing the aromatic hydrocarbon ring mentioned for the divalent aromatic hydrocarbon group in Va ¹ of the general formula (a1-1), or two or more aromatic rings. And an aryl group from which one hydrogen atom has been removed, and is preferably a phenyl group or a naphthyl group.
The cyclic aliphatic hydrocarbon group in R ¹⁰¹ is ^one in which one hydrogen atom has been removed from the monocycloalkane or polycycloalkane listed as the divalent aliphatic hydrocarbon group in Va ¹ of the general formula (a1-1). And adamantyl group and norbornyl group are preferable.
In addition, the cyclic hydrocarbon group in R ¹⁰¹ may contain a hetero atom such as a heterocyclic ring, and more specifically, each of them is represented by the general formulas (a2-r-1) to (a2-r-7). Lactone-containing cyclic group to be substituted, -SO ₂ -containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4) respectively, and the other chemical formulas (r-hr-1) And heterocyclic groups listed in (1) to (r-hr-16).

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group and the like.
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.
As an alkoxy group as a substituent, a C1-C5 alkoxy group is preferable, and a methoxy group, an ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert-butoxy group is more preferable, and methoxy is preferable. And ethoxy groups are most preferred.
As a halogen atom as a substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
As a halogenated alkyl group as a substituent, a part or all of hydrogen atoms, such as an alkyl group having 1 to 5 carbon atoms, such as methyl group, ethyl group, propyl group, n-butyl group, tert-butyl group, etc. The group substituted by the halogen atom is mentioned.

(A chain-like alkyl group which may have a substituent in R ¹⁰¹ )
The linear alkyl group of R ¹⁰¹ may be 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. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl Groups, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group and the like.
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. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methyl pentyl group, 2-methyl pentyl group, 3-methyl pentyl group, 4-methyl pentyl group etc. are mentioned.

(Acyclic alkenyl group optionally having substituent (s) for R ¹⁰¹ )
The linear alkenyl group of R ¹⁰¹ may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 and still more preferably 2 to 4 carbon atoms. Is particularly preferred. As a linear alkenyl group, a vinyl group, propenyl group (allyl group), butynyl group etc. are mentioned, for example. As a branched alkenyl group, 1-methyl propenyl group, 2-methyl propenyl group etc. are mentioned, for example.
Among the above, a propenyl group is particularly preferable as the chained alkenyl group.

Examples of the substituent in the chain 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, and a cyclic group in R ¹⁰¹ It can be mentioned.

Among them, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, it is represented by a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from polycycloalkane, and the general formulas (a2-r-1) to (a2-r-7). A lactone-containing cyclic group, an -SO ₂ -containing cyclic group represented by any of the above general formulas (a5-r-1) to (a5-r-4), and the like are preferable.

In general formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, the Y ¹⁰¹ may contain an atom other than the oxygen atom. As an atom other than an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom etc. are mentioned, for example.
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 (-O-C (= O Non-hydrocarbons such as)-), amide bond (-C (= O) -NH-), carbonyl group (-C (= O)-), carbonate bond (-O-C (= O) -O-) etc And oxygen atom-containing linking groups of the system; combinations of such non-hydrocarbon oxygen atom-containing linking groups and alkylene groups, and the like. A sulfonyl group (—SO ₂ —) may be further linked to the combination. As the said combination, the linking group respectively represented by the following general formula (y-al-1)-(y-al-7) is mentioned, for example.

［一般式（ｙ−ａｌ−１）〜（ｙ−ａｌ−７）中、Ｖ’^１０１は単結合または炭素数１〜５のアルキレン基であり、Ｖ’^１０２は炭素数１〜３０の２価の飽和炭化水素基である。］

[In general formula (y-al-1)-(y-al-7), V ' ¹⁰¹ is a single bond or a C1-C5 alkylene group, V' ¹⁰² is a C1-C30 bivalent] Is a saturated hydrocarbon group of ]

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 or a branched alkylene group, and a linear alkylene group is preferable.
Specific examples of the alkylene group as V ′ ¹⁰¹ and V ′ ¹⁰² include methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, and —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 - ; alkylethylene groups such as 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 ) alkyl ethylene group such as CH _2- ; 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 - and the like alkyl trimethylene group; tetramethylene _{[-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 - alkyl tetramethylene group and the like; pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like.
Moreover, a part of methylene group in the said alkylene group in V ' ¹⁰¹ or V' ¹⁰² may be substituted by the C5-C10 bivalent aliphatic cyclic group. The aliphatic cyclic group is preferably a divalent group in which one hydrogen atom is further removed from the cyclic aliphatic hydrocarbon group of Ra ′ ^{3 in} the formula (a1-r-1), and a cyclohexylene group 1,5-adamantylene group or 2,6-adamantylene group is more preferable.

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

In general formula (b-1), V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group in V ¹⁰¹ and the fluorinated alkylene group preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group in V ¹⁰¹ include groups in which part or all of hydrogen atoms of the alkylene group in V ¹⁰¹ are 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 general 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, and more preferably a fluorine atom.

Specific examples of the anion moiety of the general component (b-1), for example, Y ¹⁰¹ may be a single bond, include fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion; Y ¹⁰¹ When is a divalent linking group containing an oxygen atom, anions represented by any of the following general formulas (an-1) to (an-3) can be mentioned.

［式中、Ｒ”^１０１は、置換基を有していてもよい脂肪族環式基、前記化学式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−６）でそれぞれ表される基、又は置換基を有していてもよい鎖状のアルキル基であり；Ｒ”^１０２は、置換基を有していてもよい脂肪族環式基、前記一般式（ａ２−ｒ−１）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基であり；Ｒ”^１０３は、置換基を有していてもよい芳香族環式基、置換基を有していてもよい脂肪族環式基、又は置換基を有していてもよい鎖状のアルケニル基であり；Ｖ”^１０１は、フッ素化アルキレン基であり；Ｌ”^１０１は、−Ｃ（＝Ｏ）−又は−ＳＯ_２−であり；ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｎ”は０または１である。］

[Wherein, R ′ ′ ¹⁰¹ is an aliphatic cyclic group which may have a substituent, a group represented by any one of the chemical formulas (r-hr-1) to (r-hr-6), or a substituted group R ′ ′ ¹⁰² is an aliphatic cyclic group which may have a substituent, and the above-described general formulas (a2-r-1) to (a2-). a lactone-containing cyclic group represented by r-7) or a —SO ₂ — containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively; R ′ ′ ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkenyl group which may have a substituent by ^{and; V "101} is an fluorinated alkylene ^{group; L" 101} is, -C (= O) - or -SO ₂ - a and; v "each independently Is an integer of 0 to 3, q "are each independently an integer of 1 to 20, n" is 0 or 1. ]

The aliphatic cyclic group which may have a substituent of R ′ ′ ¹⁰¹ , R ′ ′ ¹⁰² and R ′ ′ ¹⁰³ is preferably the group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ above. Examples of the substituent include those similar to the substituents which may substitute the cyclic aliphatic hydrocarbon group for R ¹⁰¹ .

The aromatic cyclic group which may have a substituent in R ′ ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ described above. And the same as the substituent which may substitute the aromatic hydrocarbon group in R ¹⁰¹ .

R have a substituent in "which may chain substituted at ¹⁰¹ alkyl group, wherein preferably a group exemplified as chain alkyl group in R ¹⁰¹ .R" ¹⁰³ The chain-like alkenyl group is also preferably the group exemplified as the chain-like alkenyl group in R ¹⁰¹ above. V ′ ′ ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably —CF ₂ —, —CF ₂ CF ₂ —, —CHFCF ₂ —, —CF (CF ₃ ) CF ₂ — _{, -CH (CF 3) CF 2} - is.

Anion part of component (b-2) In the general formula (b-2), each of R ¹⁰⁴ and R ¹⁰⁵ independently has a cyclic group which may have a substituent, and a substituent It is also a chain-like alkyl group or a chain-like alkenyl group which may have a substituent, and examples thereof include the same as R ¹⁰¹ in the general formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ each are preferably a linear alkyl group which may have a substituent, and is a linear or branched alkyl group or a linear or branched fluorinated alkyl group Is more preferred.
It is preferable that carbon number of this chain | strand-shaped alkyl group is 1-10, More preferably, it is C1-C7, More preferably, it is C1-C3. The carbon number of the linear alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible because the solubility in a resist solvent is also good within the above-mentioned range of carbon numbers. Further, in the chain alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, and the high energy light and electron beams of 200 nm or less. It is preferable because the transparency is improved. The proportion of fluorine atoms in the linear alkyl group, ie, the fluorination ratio, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted by fluorine atoms. Perfluoroalkyl group.
In the general formula (b-2), each of V ¹⁰² and V ¹⁰³ independently represents a single bond, an alkylene group or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in the general formula (b-1) The thing is mentioned.
In the general formula (b-2), L ^{101 to} L ¹⁰² each independently represent a single bond or an oxygen atom.

· Anion part of component (b-3) In the general formula (b-3), each of R ^{106 to} R ¹⁰⁸ independently has a cyclic group which may have a substituent, and a substituent It is also a chain-like alkyl group or a chain-like alkenyl group which may have a substituent, and examples thereof include the same as R ¹⁰¹ in the general formula (b-1).
L ^{103 to} L ¹⁰⁵ are each independently a single bond, -CO- or -SO _2- .

{Cation part}
In the general formulas (b-1), (b-2) and (b-3), M ' ^{m +} is an m-valent organic cation, preferably a sulfonium cation or an iodonium cation, and The cations represented by formulas (ca-1) to (ca-4) are particularly preferred.

［一般式（ｃａ−１）〜（ｃａ−４）中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１１〜Ｒ^２１２は、それぞれ独立に置換基を有していてもよいアリール基、アルキル基またはアルケニル基を表し、Ｒ^２０１〜Ｒ^２０３、Ｒ^２０６〜Ｒ^２０７、Ｒ^２１１〜Ｒ^２１２は、相互に結合して式中のイオウ原子と共に環を形成してもよい。Ｒ^２０８〜Ｒ^２０９はそれぞれ独立に水素原子または炭素数１〜５のアルキル基を表し、Ｒ^２１０は置換基を有していてもよいアリール基、アルキル基、アルケニル基、又は−ＳＯ_２−含有環式基であり、Ｌ^２０１は−Ｃ（＝Ｏ）−または−Ｃ（＝Ｏ）−Ｏ−を表し、Ｙ^２０１は、それぞれ独立に、アリーレン基、アルキレン基またはアルケニレン基を表し、ｘは１または２であり、Ｗ^２０１は（ｘ＋１）価の連結基を表す。］

[In the general formulas (ca-1) to (ca-4), each of R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent] R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ and R ^{211 to} R ²¹² may be mutually bonded to form a ring with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon ^{atoms, R 210} is an optionally substituted aryl group, an alkyl group, an alkenyl group, or -SO ₂ - containing L ²⁰¹ represents a cyclic group, L ²⁰¹ represents —C (= O) — or —C (、 O) —O—, Y ²⁰¹ represents each independently an arylene group, an alkylene group or an alkenylene group, and x represents And W ²⁰¹ represents a (x + 1) -valent linking group. ]

As the aryl group in R ²⁰¹ to R ^207, and ^R 211 ^{to R 212,} include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.
The alkyl group of R ²⁰¹ to R ^207, and ^R 211 ^{to R 212,} a chain or cyclic alkyl group, preferably from 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 which 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 and an arylthio group. And groups represented by general formulas (ca-r-1) to (ca-r-7) shown below.
The aryl group in the arylthio group as a substituent is the same as that described for R ¹⁰¹ , and specific examples thereof include a phenylthio group or a biphenylthio group.

［一般式（ｃａ−ｒ−１）〜（ｃａ−ｒ−７）中、Ｒ’^２０１はそれぞれ独立に、水素原子、置換基を有していてもよい環式基、鎖状のアルキル基、または鎖状のアルケニル基である。］

[In the general formulas (ca-r-1) to (ca-r-7), each of R ' ²⁰¹ independently represents a hydrogen atom, a cyclic group which may have a substituent, or a chain alkyl group, Or a linear alkenyl group. ]

The cyclic group which may have a substituent of R ′ ^201, the chain-like alkyl group which may have a substituent, or the chain-like alkenyl group which may have a substituent is In addition to the same groups as R ¹⁰¹ in the general formula (b-1), the above-mentioned general groups may be substituted cyclic groups which may have a substituent or a chain alkyl group which may have a substituent. The same acid dissociable group represented by the formula (a1-r-2) can also be mentioned.

When R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ and R ^{211 to} R ²¹² are mutually bonded to form a ring with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom or a nitrogen atom, carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. May be bonded via a functional group of As the ring to be formed, one ring containing a sulfur atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring, including a sulfur atom, and particularly preferably a 5- to 7-membered ring preferable. 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, thianthrene ring, phenoxathiin ring, tetrahydrofuran Thiophenium rings, tetrahydrothiopyranium rings and the like can be mentioned.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms are preferred, and combined if mutually serving as alkyl ring May be formed.

R ²¹⁰ may have 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 substituent -SO ₂ - containing cyclic group.
As an aryl group in R ^210, a C6-C20 unsubstituted aryl group is mentioned, A phenyl group and a naphthyl group are preferable.
The alkyl group in R ²¹⁰ is preferably a linear 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) above And the group represented by the above general formula (a5-r-1) is preferable.

Each Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkenylene group.
The arylene group in Y ²⁰¹ is a group in which one hydrogen atom is removed from the aryl group exemplified as the aromatic hydrocarbon group in R ¹⁰¹ in the general formula (b-1) above.
Examples of the alkylene group and the alkenylene group in Y ²⁰¹ include the same as the aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ in the general formula (a1-1).

In the general formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, ie, a divalent or trivalent linking group.
Examples of the divalent linking group for W ^201, a divalent hydrocarbon group which may have a substituent is preferably a hydrocarbon group similar to Ya ²¹ in the general formula (a2-1) can be exemplified. The divalent linking group in W ²⁰¹ may be linear, branched or 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. As an arylene group, a phenylene group, a naphthylene group, etc. are mentioned, A phenylene group is especially preferable.
^Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like It can be mentioned. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

  Specific examples of suitable cations represented by General Formula (ca-1) include cations represented by the following Formulas (ca-1-1) to (ca-1-63).

［式（ｃａ−１−３４）〜（ｃａ−１−３６）中、ｇ１、ｇ２、ｇ３は繰返し数を示し、ｇ１は１〜５の整数であり、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

[In the formulas (ca-1-34) to (ca-1-36), g1, g2 and g3 represent the number of repetitions, g1 is an integer of 1 to 5, and g2 is an integer of 0 to 20, g3 is an integer of 0-20. ]

［式（ｃａ−１−５８）中、Ｒ”^２０１は水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[In Formula (ca-1-58), R ′ ′ ²⁰¹ is a hydrogen atom or a substituent, and the substituent may be a substituent that the R ^{201 to} R ²⁰⁷ and the R ^{210 to} R ²¹² may have. It is the same as that mentioned as

  Specific examples of suitable cations represented by the general formula (ca-3) include cations represented by the following general formulas (ca-3-1) to (ca-3-6).

  Specific examples of suitable cations represented by the general formula (ca-4) include cations represented by the following chemical formulas (ca-4-1) to (ca-4-2).

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
In the present embodiment, when the resist composition contains the component (B), the content of the component (B) is preferably 0.5 to 60 parts by mass, and 1 to 50 parts by mass with respect to 100 parts by mass of the component (A). A part is more preferable, and 1-40 mass parts is further more preferable. By setting the content of the component (B) in the above range, pattern formation is sufficiently performed. In addition, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is obtained, and storage stability is preferably improved.

[Specific compound (E)]
In the present embodiment, an organic carboxylic acid, an oxo acid of phosphorus, and a derivative thereof are used as optional components in the resist composition for the purpose of preventing sensitivity deterioration and improving resist pattern shape, storage stability over time, and the like. And at least one compound (E) (hereinafter referred to as component (E)) selected from the group consisting of
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 phosphorus oxo acids include phosphoric acid, phosphonic acid and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of derivatives of oxo acids of phosphorus include esters in which a hydrogen atom of the above oxo acid is substituted with a hydrocarbon group, and examples of the hydrocarbon group include alkyl groups having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like can be mentioned.
Examples of derivatives of phosphoric acid include phosphoric acid di-n-butyl ester, phosphoric acid esters such as phosphoric acid diphenyl ester, and the like.
Examples of derivatives of phosphonic acid include phosphonic acid dimethyl ester, phosphonic acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid esters such as phosphonic acid dibenzyl ester, and the like.
Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
As the component (E), one type may be used alone, or two or more types may be used in combination.
Component (E) is used usually in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of component (A).

[(F) component]
In the present embodiment, the resist composition may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film.
Examples of the component (F) include, for example, JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226. The fluorine-containing polymer compounds described can be used.
More specific examples of the component (F) include polymers having a structural unit (f1) represented by the following general formula (f1-1). As the polymer, a polymer (homopolymer) consisting only of a structural unit (f1) represented by the following general formula (f1-1); a structural unit (f1) represented by the following general formula (f1-1) A copolymer of the structural unit (a1), a structural unit (f1) represented by the following general formula (f1-1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit ( It is preferable that it is a copolymer with a1). Here, as the structural unit (a1) to be copolymerized with the structural unit (f1) represented by the following general formula (f1-1), 1-ethyl-1-cyclooctyl (meth) acrylate or the above general formula The structural unit represented by (a1-2-01) is preferable.

［一般式（ｆ１−１）中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｒｆ^１０２およびＲｆ^１０３はそれぞれ独立して水素原子、ハロゲン原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基を表し、Ｒｆ^１０２およびＲｆ^１０３は同じであっても異なっていてもよい。ｎｆ^１は１〜５の整数であり、Ｒｆ^１０１はフッ素原子を含む有機基である。］

[In general formula (f1-1), R is a hydrogen atom, an alkyl group of 1 to 5 carbon atoms, or a halogenated alkyl group of 1 to 5 carbon atoms. 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. It may be different. nf ¹ is an integer of ¹ to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom. ]

In general formula (f1-1), R is as defined above. As R, a hydrogen atom or a methyl group is preferable.
As a halogen atom of Rf ¹⁰² and Rf ¹⁰³ in general formula (f1-1), a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, Especially a fluorine atom is preferable. Examples of the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and ^{Rf 103,} the same alkyl group of 1 to 5 carbon atoms in the R, and a methyl group or an ethyl group is preferred. As the halogenated alkyl group of 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ , specifically, a group in which part or all of hydrogen atoms of the above-mentioned alkyl group of 1 to 5 carbon atoms are substituted with a halogen atom is It can be mentioned. 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, as Rf ¹⁰² and Rf ¹⁰³ , a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom, a fluorine atom, a methyl group or an ethyl group is preferable.
In General Formula (f1-1), nf ¹ is an integer of ¹ to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In the general 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 linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, and more preferably 1 to 15 carbon atoms. And 1 to 10 carbon atoms are particularly preferred.
Moreover, as for the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the said hydrocarbon group are fluorinated, It is more preferable that 50% or more is fluorinated, 60% or more Fluorination is particularly preferable because the hydrophobicity of the resist film at the time of immersion exposure is increased.
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 And -CH ₂ -CH ₂ -CF ₃ and -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are most preferable.

1000-50000 are preferable, as for the weight average molecular weight (Mw) (the polystyrene conversion standard by gel permeation chromatography) of (F) component, 5000-40000 are more preferable, and 10000-30000 are the most preferable. When it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is above the lower limit of this range, the dry etching resistance and the resist pattern cross-sectional shape are good.
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.

As the component (F), one type may be used alone, or two or more types may be used in combination.
Component (F) is used usually in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of component (A).

  In the present embodiment, the resist composition may further contain additives which are optionally miscible, for example, an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent. An agent, a dye, etc. can be suitably added and contained.

[(S) component]
In the present embodiment, 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 component can be used as long as it can dissolve each component to be used to form a uniform solution, and any one of conventionally known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone (2-heptanone), methyl isopentyl ketone, etc. ethylene glycol, diethylene glycol, propylene glycol, Polyhydric alcohols such as propylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, the above polyhydric alcohols or compounds having the ester bond Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane; Esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl Ether, diphenylether, dibenzylether, phenetole, butylphenylether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene And aromatic organic solvents such as dimethyl sulfoxide (DMSO).
These organic solvents may be used alone or in combination of two or more.
Among them, PGMEA, PGME, γ-butyrolactone, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The compounding ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, etc., but is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be in the range.
More specifically, in the case of blending EL or cyclohexanone 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. . Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably 1: 9-9: 1, More preferably, 2: 8-8: 2, More preferably, 3: 7-7: It is three.
In addition, as the component (S), mixed solvents of at least one selected from PGMEA and EL and γ-butyrolactone are also preferable. In this case, the mass ratio of the former and the latter is preferably 70:30 to 95: 5 as the mixing ratio.
The amount of the component (S) to be used is not particularly limited, and can be appropriately set according to the applied film thickness, at a concentration that can be applied to a substrate or the like. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

«A solution containing an acid or thermal acid generator»
A solution containing an acid or a thermal acid generator used in the present embodiment will be described. The solution containing an acid or a thermal acid generator includes, for example, one obtained by dissolving an acid or a thermal acid generator (hereinafter, these are also referred to as “acid component”) and a base component in a solvent.

[Acid (acid component (T0))]
In the present embodiment, the “acid” itself is acidic and acts as a proton donor (hereinafter sometimes referred to as “acid component (T0)”). As such (T0) component, the acid which has not formed the salt is mentioned.
Examples of the component (T0) include acid components such as fluorinated alkyl group-containing carboxylic acids, higher fatty acids, higher alkyl sulfonic acids, higher alkyl aryl sulfonic acids and camphor sulfonic acids.

As the fluorinated alkyl group-containing carboxylic acid, for example, C ₁₀ F ₂₁ COOH and the like can be mentioned.
Examples of the higher fatty acids include higher fatty acids having an alkyl group having 8 to 20 carbon atoms, and specific examples include dodecanoic acid, tetradecanoic acid, and stearic acid.
The alkyl group having 8 to 20 carbon atoms may be linear or branched, and a phenylene group or an oxygen atom may be interposed in the chain, or hydrogen in the alkyl group A part of the atoms may be substituted by a hydroxyl group or a carboxy group.
Examples of higher alkyl sulfonic acids include sulfonic acids having an alkyl group having an average carbon number of preferably 9 to 21, and more preferably 12 to 18, and specifically, decanesulfonic acid, dodecanesulfonic acid, tetradecanesulfonic acid And pentadecanesulfonic acid and stearic acid sulfonic acid.
Examples of higher alkyl aryl sulfonic acids include alkyl benzene sulfonic acids and alkyl naphthalene sulfonic acids having an alkyl group preferably having an average carbon number of 6 to 18, and more preferably 9 to 15, and specifically, dodecyl benzene sulfone. The acids include decyl naphthalene sulfonic acid.

  Examples of other acid components include alkyl diphenyl ether disulfonic acids having an alkyl group preferably having an average carbon number of 6 to 18, and more preferably 9 to 15, and specific examples include dodecyl diphenyl ether disulfonic acid and the like.

[Thermal acid generator (acid component (T1))]
The thermal acid generator (hereinafter sometimes referred to as "acid component (T1)") is a component that generates an acid upon heating. So far, onium salt-based acid generators such as iodonium salts and sulfonium salts; oxime sulfonate-based acid generators; bisalkyls or bisarylsulfonyldiazomethanes; poly (bis) A wide variety of products are known such as diazomethane-based acid generators such as sulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators; iminosulfonate-based acid generators; disulfone-based acid generators. These acid generator components, which are also known as photoacid generators, also function as thermal acid generators. Therefore, as an acid generator component that can be used in the present embodiment, any one of conventionally known acid generators for chemically amplified resist compositions can be used.
Especially, as an acid component (T1), the compound represented by either of following General formula (T1-1)-(T1-3) is preferable.

［一般式（Ｔ１−１）〜（Ｔ１−３）中、Ｒｔ^１０１、Ｒｔ^１０４〜Ｒｔ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒｔ^１０４、Ｒｔ^１０５は、相互に結合して環を形成していてもよい。Ｒｔ^１０６〜Ｒｔ^１０７のいずれか２つは、相互に結合して環を形成していてもよい。Ｒｔ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基である。Ｙｔ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖｔ^１０１〜Ｖｔ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌｔ^１０１〜Ｌｔ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌｔ^１０３〜Ｌｔ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。Ｒｔ^３０１〜Ｒｔ^３０４は、それぞれ独立に、水素原子又は炭素数１〜１２の直鎖状、分岐鎖状若しくは環状のフッ素化アルキル基である。Ｒｔ^３０１〜Ｒｔ^３０３は、相互に結合して式中の窒素原子と共に環を形成していてもよい。］

[In the general formulas (T1-1) to (T1-3), Rt ¹⁰¹ and Rt ^{104 to} Rt ¹⁰⁸ may each independently have a cyclic group which may have a substituent or a substituent] It is a chained alkyl group or a chained alkenyl group which may have a substituent. Rt ¹⁰⁴ and Rt ¹⁰⁵ may be bonded to each other to form a ring. Any two of Rt ^{106 to} Rt ¹⁰⁷ may be bonded to each other to form a ring. Rt ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Yt ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. Vt ^{101 to} Vt ¹⁰³ each independently represent a single bond, an alkylene group, or a fluorinated alkylene group. Lt ^{101 to} Lt ¹⁰² each independently represent a single bond or an oxygen atom. Lt ^{103 to} Lt ¹⁰⁵ are each independently a single bond, -CO- or -SO _2- . Rt ^{301 to} Rt ³⁰⁴ each independently represent a hydrogen atom or a linear, branched or cyclic fluorinated alkyl group having 1 to 12 carbon atoms. Rt ^{301 to} Rt ³⁰³ may be bonded to each other to form a ring with the nitrogen atom in the formula. ]

{Anion part}
· Anion part of (T1-1) component In the general formula (T1-1), Rt ¹⁰¹ is a cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent Or a chain-like alkenyl group which may have a substituent.
In the general formula (T1-1), the description of Rt ^{101 is the same} as the description of R ¹⁰¹ in the general formula (b-1).

In general formula (T1-1), Yt ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
The description of Yt ¹⁰¹ in General Formula (T1-1) is the same as the description of Y ^{101 in} General Formula (b-1).

In general formula (T1-1), Vt ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group in Vt ¹⁰¹ and the fluorinated alkylene group preferably have 1 to 4 carbon atoms. As the fluorinated alkylene group for Vt ^101, some or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms in the vt ^101. Among them, Vt ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In General Formula (T1-1), Rt ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Rt ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

Specific examples of the anion moiety of the component (T1-1) include, for example, when Yt ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion and perfluorobutane sulfonate anion, etc. are mentioned; Yt ¹⁰¹ is When it is a bivalent coupling group containing an oxygen atom, the anion represented by either of the said General Formula (an-1)-(an-3) is mentioned.

-Anion part of (T1-2) component In general formula (T1-2), Rt ¹⁰⁴ and Rt ¹⁰⁵ each independently have a cyclic group which may have a substituent, and a substituent. A chain-like alkyl group which may be substituted or a chain-like alkenyl group which may have a substituent, each of which is similar to Rt ¹⁰¹ in the general formula (T1-1). However, Rt ¹⁰⁴ and Rt ¹⁰⁵ may be bonded to each other to form a ring.
Rt ¹⁰⁴ and Rt ¹⁰⁵ each are preferably a linear alkyl group which may have a substituent, and is a linear or branched alkyl group, or a linear or branched fluorinated alkyl group Is more preferred.
It is preferable that carbon number of this chain | strand-shaped alkyl group is 1-10, More preferably, it is C1-C7, More preferably, it is C1-C3. The carbon number of the linear alkyl group of Rt ¹⁰⁴ and Rt ¹⁰⁵ is preferably as small as possible because the solubility in a resist solvent is also good within the above-mentioned range of carbon numbers. Further, in the chain alkyl group of Rt ¹⁰⁴ and Rt ^105, the larger the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, and the high-energy light or electron beam of 200 nm or less. It is preferable because the transparency is improved. The proportion of fluorine atoms in the linear alkyl group, ie, the fluorination ratio, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted by fluorine atoms. Perfluoroalkyl group.
In general formula (T1-2), Vt ¹⁰² and Vt ¹⁰³ each independently represent a single bond, an alkylene group, or a fluorinated alkylene group, and each is the same as Vt ¹⁰¹ in general formula (T1-1) The thing is mentioned.
In the general formula (T1-2), Lt ^{101 to} Lt ¹⁰² each independently represent a single bond or an oxygen atom.

· Anion part of (T1-3) component In the general formula (T1-3), Rt ^{106 to} Rt ¹⁰⁸ each independently have a cyclic group which may have a substituent, and have a substituent A chain-like alkyl group which may be substituted or a chain-like alkenyl group which may have a substituent, each of which is similar to Rt ¹⁰¹ in the general formula (T1-1).
Lt ^{103 to} Lt ¹⁰⁵ are each independently a single bond, -CO- or -SO _2- .

{Cation part}
In the cation moiety of the general formulas (T1-1) to (T1-3), Rt ^{301 to} Rt ³⁰⁴ each independently represent a hydrogen atom or a linear, branched or cyclic fluorinated group having 1 to 12 carbon atoms It is an alkyl group. Rt ^{301 to} Rt ³⁰³ may be bonded to each other to form a ring with the nitrogen atom in the formula. As the ring to be formed, one ring containing a nitrogen atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring, including a nitrogen atom, and particularly preferably a 5- to 7-membered ring preferable. As a specific example of the ring formed, a pyridine ring etc. are mentioned, for example. Hereafter, the preferable specific example of the cation part of a compound represented by general formula (T1-1)-(T1-3) is enumerated.

  As a suitable thing of an acid component (T1), the compound represented by the said General formula (T1-1) is preferable, As an anion part of a compound represented by the said General formula (T1-1), the said Formula ( The anion moiety represented by an-1) is preferred.

  In the embodiment, as the acid component (T1), a compound (T1) -1 shown below is preferable.

As the solution containing an acid or a thermal acid generator, the above-mentioned acid components (T0) or (T1) may be used alone or in combination of two or more. Among them, the acid component (T1) is preferable.
The content of the acid component (T0) or (T1) in the solution containing the acid or thermal acid generator in the present embodiment is 0.1 to 5 parts by mass with respect to 100 parts by mass of the below-mentioned base component (Tp). Part is preferable, 0.15 to 3 parts by mass is more preferable, and 0.15 to 1.5 parts by mass is more preferable.

[Base component (Tp)]
In the present embodiment, a substrate component which is preferably included in a solution containing an acid or a thermal acid generator will be described. The base material component that the solution containing the acid or thermal acid generator preferably has may be described as "base component (Tp)". The base component (Tp) improves the coatability of the solution containing an acid or a thermal acid generator and can be removed in organic solvent development in step D, that is, particularly a base component that dissolves in an organic solvent. It is not limited.
In the present embodiment, the base component (Tp) preferably includes a polymer compound (Tp1) including a structural unit having a hydrocarbon group which may have a substituent. As a structural unit which has a hydrocarbon group which may have a substituent, the structural unit represented by the following general formula (Tp) -1 is mentioned, for example.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｒｔｐは置換基を有していてもよい炭化水素基である。ｎ_ｔｐは０又は１である。］

Wherein R is a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms, and Rtp is a hydrocarbon group which may have a substituent. n _tp is 0 or 1. ]

In the general formula (Tp) -1, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and the explanation for R in the general formula (a1-1) In the same formula (Tp) -1, R is preferably a hydrogen atom or a methyl group.
In general formula (Tp) -1, Rtp is a hydrocarbon group which may have a substituent.

As a hydrocarbon group in Rtp, a C1-C20 alkyl group, a C1-C10 alkyl group; a linear or branched alkyl group is mentioned. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1 -Diethyl propyl group, 2, 2- dimethyl propyl group, 2, 2- dimethyl butyl group etc. are mentioned.
When Rtp is a cyclic hydrocarbon group, it may be aliphatic or aromatic, may be polycyclic, or may be monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cyclooctane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from polycycloalkane is preferable, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferable, and specifically, adamantane , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When Rtp is an aromatic hydrocarbon group, specific examples of the aromatic ring to be contained include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene and the like; carbon constituting the aromatic hydrocarbon ring And aromatic heterocycles in which a part of the atoms is substituted with a heteroatom. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, as the aromatic hydrocarbon group, a group (aryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring; a group in which one hydrogen atom of the aryl group is substituted with an alkylene group (for example, And arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc .; and the like. The carbon number of the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

Rtp 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, a carbonyl group and the like.
The alkyl group as the substituent is preferably an alkyl group having a carbon number of 1 to 5, 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 a carbon number of 1 to 5, and is preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, methoxy And ethoxy groups are most preferred.
As a halogen atom as the said substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
As a halogenated alkyl group as said substituent, the group by which one part or all part of the hydrogen atom of the said alkyl group was substituted by the said halogen atom is mentioned.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. The substituent containing a hetero atom, -O -, - C (= O) -O -, - S -, - S (= O) 2 -, - S (= O) 2 -O- are preferred.

The structural unit represented by the general formula (Tp) -1 is derived from a structural unit ((Tp) -1-1) containing a polar group-containing aliphatic hydrocarbon group having a polar group as a substituent, and hydroxystyrene Structural unit ((Tp) -1-2), structural unit derived from styrene ((Tp) -1-3), structural unit containing a linear or cyclic aliphatic hydrocarbon group ((Tp) -1 -4) and the structural unit ((Tp) -1-5) derived from vinyl alcohol are mentioned as a preferable thing.
In the embodiment, as the structural unit (Tp) -1-1, a structural unit (a3) containing the above-mentioned polar group-containing aliphatic hydrocarbon group is preferable, and in particular, the structural unit (a3-1) or The structural unit represented by a3-3) is preferable.
Examples of the structural unit (Tp) -1-2 include structural units represented by general formula (Tp) -1-2-1 shown below. As the structural unit (Tp) -1-3, structural units represented by general formula (Tp) -1-3-1 shown below can be mentioned.

［一般式（Ｔｐ）−１−２−１中、Ｒ^ｓｔは水素原子またはメチル基を表し、ｍ_０１は１〜３の整数を表す。］

[In general formula (Tp) -1-2-1, R ^st represents a hydrogen atom or a methyl group, and m ₀₁ represents an integer of 1 to 3. ]

［一般式（Ｔｐ）−１−３−１中、Ｒ^ｓｔは水素原子又はメチル基を表し、Ｒ^０１は炭素数１〜５のアルキル基を表し、ｍ_０２は０または１〜３の整数を表す。］

[In the general formula (Tp) -1-3-1, 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 is an integer of 0 or 1 to 3] Represent. ]

In the above general formula (Tp) -1-2-1, R ^st is a hydrogen atom or a methyl group, preferably a hydrogen atom.
m ₀₁ is an integer of 1 to 3; Among these, m ₀₁ is preferably 1.
The position of the hydroxyl group may be any of o-position, m-position and p-position, but since m is 1 and has a hydroxyl group at p-position, as it is easily available and inexpensive. preferable. When m ₀₁ is 2 or 3, arbitrary substitution positions can be combined.

In the above general formula (Tp) -1-3-1, R ^st is a hydrogen atom or a methyl group, preferably a hydrogen atom.
The above R ⁰¹ is a linear or branched alkyl group having 1 to 5 carbon atoms, and is methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl And neopentyl groups. Industrially, a methyl group or an ethyl group is preferable.

The above m ₀₂ is an integer of 0 or 1 to 3. Among these, m ₀₂ is preferably 0 or 1, and particularly preferably 0 from the industrial viewpoint.
When m ₀₂ is 1, the substitution position of R ⁰¹ may be any of o-position, m-position and p-position, and further, when m ₀₂ is 2 or 3, any substitution may be performed. The positions can be combined.

  As the structural unit (Tp) -1-4, a structural unit represented by any one of the above-mentioned general formulas (a4-1) to (a4-7), or a structural unit represented by the following general formula (Tp) -4-1 The structural unit represented is mentioned.

［一般式（Ｔｐ）−１−４−１中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｒｔｐ^０４は、炭素数１〜１０の直鎖状のアルキル基である。］

[In the general formula (Tp) -1-4-1, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rtp ⁰⁴ has 1 to 10 carbon atoms Is a linear alkyl group of ]

As a high molecular compound (Tp1) which a base material component (Tp) contains, the structural unit represented by said (Tp) -1-2-1, and the structural unit represented by said (Tp) -1-3-1 Copolymers thereof, copolymers of the structural units represented by (Tp) -1-2 and the structural units represented by (Tp) -1-3, and in (Tp) -1-1 The copolymer containing 2 or more types of the structural unit represented, and the copolymer containing 2 or more types of the structural unit represented by said (Tp) -1-4 are mentioned as a preferable thing.
By setting it as said base-material component (Tp), it can prevent that melt | dissolution of a 1st resist pattern and a 1st layer and the layer containing an acid diffusion control agent mixing altogether. In addition to this, in organic solvent development in a later step, solubility in the organic solvent can be made favorable.

  As the solution containing an acid or a thermal acid generator, the above-mentioned base component (Tp) may be used singly or in combination of two or more.

〔solvent〕
In the present embodiment, a solvent (hereinafter sometimes referred to as “solvent (Ts)”) that is preferably contained in a solution containing an acid or a thermal acid generator will be described. In step B, a solution containing an acid or a thermal acid generator is applied to cover the first resist pattern to form a first layer. For this reason, the solvent (Ts) contained in the solution containing an acid or a thermal acid generator is preferably a solvent which does not dissolve the first resist pattern.
Specifically, it is preferable to use water, an ether-based solvent or a linear monovalent alcohol having 1 to 10 carbon atoms.
The ether solvent is an organic solvent containing C—O—C in the structure. Examples include diethyl ether, 1- (isopentyloxy) -3-methylbutane, diisopropyl ether, tetrahydrofuran and the like.
The alcohol solvent is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol, 4- 4- Methylpentan-2-ol, 2-methylbutan-1-ol and the like can be mentioned. Among these, 4-methyl-2-pentanol or 2-methylbutan-1-ol is more preferable.

  The amount of the solvent (Ts) to be used is not particularly limited, and is appropriately set according to the applied film thickness at a concentration that can be applied onto the first resist pattern. Generally, it is used such that the solid content concentration of the solution containing the acid or thermal acid generator is in the range of 0.1 to 10% by mass, preferably 1 to 5% by mass.

[A solution containing an acid diffusion control agent]
The solution containing the acid diffusion control agent used in step B1 (hereinafter sometimes referred to as "solution (Q1)") is not particularly limited as long as it can control the action of an acid.
As the solution (Q1), it is possible to use one in which an acid diffusion control agent and a base component (Qp) are dissolved in a solvent.

The acid diffusion control agent contained in the solution (Q1) is not particularly limited as long as it acts as a quencher for trapping the acid of the acid component in the first layer. In the present embodiment, it is preferable to adopt the nitrogen-containing organic compound component described as the component (D2) in the resist composition.
Among them, alkylamines are preferable, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine and tri-n-octylamine are particularly preferable.
The acid diffusion control agent may be an ionic nitrogen-containing organic compound component, and a cation moiety represented by the following general formula (Cd), and an anion moiety represented by the above general formula (d1-1), The compound which consists of is preferable.

［一般式（Ｃｄ）中、Ｒｄ^ｃ１〜Ｒｄ^ｃ３は、それぞれ独立に、置換基を有していてもよいアルキル基である。］

[In general formula (Cd), Rd ^{c1 to} Rd ^c3 each independently represent an alkyl group which may have a substituent. ]

In the general formula (Cd), Rd ^{c1 to} Rd ^c3 are each independently an alkyl group which may have a substituent. As Rd ^{c1 to} Rd ^c3 , each independently, a linear alkyl group of 1 to 5 carbon atoms is preferable.

As the solution (Q1), one type of acid diffusion control agent described above may be used alone, or two or more types may be used in combination.
In a solution containing an acid diffusion control agent in the present embodiment, the content of the acid diffusion control agent is preferably 10 to 30 parts by mass, and 12 to 25 parts by mass with respect to 100 parts by mass of a base component (Qp) described later. Is more preferable, and 15 to 20 parts by mass is further preferable.

[Base material component (Qp)]
It is preferable that the suitable base-material component (Qp) which solution (Q1) contains contains the said high molecular compound (Tp1).
As the base component (Qp), a copolymer of a structural unit represented by the above general formula (Tp) -1-2 and a structural unit represented by the above general formula (Tp) -1-3, the above general A copolymer containing two or more structural units represented by the formula (Tp) -1-4, a structural unit represented by the above general formula (Tp) -1-1, and the above general formula (Tp) -1 A copolymer with the structural unit represented by 4 is mentioned as a preferable thing.
By using the above-mentioned base material component (Qp), it is considered that the dissolution of the first resist pattern and the overall mixing of the first layer with the layer containing the acid diffusion control agent can be prevented. In addition to this, in organic solvent development in a later step, it is considered that the solubility in the organic solvent can be made good.

  As the solution (Q1), the above-mentioned base components (Qp) may be used alone or in combination of two or more.

In the present embodiment, the solvent (Ts) and the solvent (Qs) listed above may be the same or different.
If different, for example, a monohydric alcohol solvent may be selected as the solvent (Ts), and an ether solvent may be employed as the solvent (Qs), and a monohydric alcohol solvent may be employed as the solvent (Ts) A solvent may be selected, and an ether solvent may be adopted as the solvent (Qs), water may be selected as the solvent (Ts), and an ether solvent may be adopted as the solvent (Qs). A monovalent alcohol solvent may be selected as Ts), and water may be adopted as the solvent (Qs).

  The amount of the solvent (Qs) to be used is not particularly limited, and is appropriately set according to the applied film thickness, at a concentration that can be applied onto the first layer. In general, the solid content concentration of the solution (Q1) is used in the range of 0.1 to 10% by mass, preferably 1 to 5% by mass.

«Positive resist composition for split pattern formation»
A second aspect of the present embodiment is a resist composition used in the method for forming a resist pattern according to the first aspect of the present invention, which generates an acid upon exposure to light, and is soluble in a developer by the action of the acid. A resist composition for forming a split pattern, comprising: an acid diffusion control agent, wherein the acid diffusion control agent contains an acid having an acid dissociation constant of 3.0 or more. It is a thing.
The description of the resist composition for forming a split pattern according to the second aspect of the present embodiment is the same as the explanation regarding the resist composition described in the step A in the method for forming a resist pattern according to the first aspect of the present invention. .

  The resist composition for forming a split pattern of the present embodiment can be suitably used for the formation of a so-called split pattern, which is a fine pattern obtained by dividing the first resist pattern.

  EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to the following examples.

<< Preparation of positive resist composition >>
The positive resist compositions 1 to 6 shown in the following Table 1 (described as "resist compositions 1 to 6" in the following table) were respectively prepared.

In the above Table 1, each symbol has the following meaning. The numerical value in [] means the compounding amount (parts by mass).
-(A) -1: Following high molecular compound (A) -1.
(B) -1: The following compound (B) -1:
-(D) -1-(D) -6: Following compound (D) -1-(D) -6.
-(F) -1: Following high molecular compound (F) -1.
(E) -1: salicylic acid.
A mixed solvent of (S) -1: PGMEA / PGME / cyclohexanone = 45/30/25 (mass ratio).
(S) -2: γ-butyrolactone.

«Preparation of solution containing acid»
100 parts by mass of the following polymer compound (AP) -1, 40 parts by mass of the following compound (T) -1, 17000 parts by mass of a solvent (4-methyl-2-pentanol) are mixed, and a solution containing an acid component Was prepared.

<< Preparation of a solution containing an acid diffusion control agent >>
A solution containing an acid diffusion control agent was prepared by mixing 100 parts by mass of the following polymer compound (BP) -1, 20 parts by mass of trioctylamine, and 10000 parts by mass of a solvent (isoamyl ether).

<Formation of resist pattern>
«Test Examples 1 to 6»
Using the positive resist compositions 1 to 6 of each example prepared above, a split pattern was formed by the method for forming a resist pattern of the embodiment shown in FIG. The resist pattern formation methods using the positive resist compositions 1 to 6 were referred to as Test Examples 1 to 6, respectively. Among Test Examples 1 to 6, Test Examples 1 to 3 are to which the present invention is applied.

[Step A]
An organic antireflection film composition "ARC 29A" (trade name, manufactured by Brewer Science Inc.) is applied on a 12-inch silicon wafer using a spinner, baked on a hot plate at 205 ° C. for 60 seconds, and dried. As a result, an organic antireflective film having a film thickness of 89 nm was formed as a support.
Next, the positive resist compositions 1 to 6 obtained above are coated on the organic antireflective film using a spinner, respectively, and prebaked (PAB) on a hot plate at a temperature of 110 ° C. for 60 seconds. The treatment was performed and dried to form a resist film having a film thickness of 90 nm.
Next, an ArF excimer laser (193 nm) is selected for the resist film through a mask pattern (binary mask; mask size 59 nm) using an exposure apparatus NSR-S609B (manufactured by Nikon Corporation, NA = 1.07 Dipole with polano). Irradiated.
Next, alkaline development was performed for 10 seconds at 23.degree. C. using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
Thereafter, a post-exposure bake (PEB) at 85 ° C. for 60 seconds was performed.
As a result, a first resist pattern of a line and space pattern of 118 nm pitch / 73 nm line (hereinafter referred to as “LS pattern”) was formed.

[Step B]
A solution containing the acid obtained above is applied using a spinner on the silicon wafer obtained in [Step A] and on which the first resist pattern is formed, so as to cover the first resist pattern ( A structure consisting of a first resist pattern and a first layer covering the first resist pattern was obtained (1500 rpm).

[Step B1]
A solution containing an acid diffusion control agent was applied by spin coating so as to cover the structure obtained in the above [Step B].

[Step C]
The structure to which the solution containing an acid diffusion control agent was applied in the step B1 was baked at 110 ° C. for 60 seconds.

[Step D]
After the day of [Step C], the baked structure was subjected to an organic solvent development treatment for 13 seconds using butyl acetate. Thereby, a split pattern was formed.

  The following evaluation was performed about the formed split pattern.

[Evaluation of pattern dimensions]
The split pattern formed above is observed from the sky above the pattern by a CD-SEM (scanning electron microscope, accelerating voltage 300 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation), and about 100 points in the split pattern Each line width (nm) was measured. The results are shown in Table 2 below as "CD (nm)".
Here, the line width refers to the width of the organic solvent insoluble region 1 Pa in the cross section of the pattern shown in FIG. 2 (D).

[Evaluation of pattern height]
About the said split pattern, pattern height (nm) of each line was measured by length measurement SEM (scanning electron microscope, 300 V of acceleration voltages, brand name: S-9380, Hitachi High-Technologies company make). The results are shown in Table 2 below as “pattern height (nm)”.
In addition, the pattern height here means the height of the organic solvent insoluble area | region 1 Pa in the pattern cross section shown by FIG. 2 (D).

[Evaluation of LWR (Line Wise Roughness)]
For the split pattern formed above, 3σ, which is a measure showing LWR, was determined.
“3σ” is the top surface of the line (developer insoluble region 1 Pa in the cross section of the pattern shown in FIG. 2D) by a scanning electron microscope (accelerating voltage 800 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation) The 400 line positions are measured in the longitudinal direction in the visual direction, and the triple value (3σ) (unit: nm) of the standard deviation (σ) obtained from the measurement results is shown.
As the value of 3σ is smaller, the roughness of the line sidewall is smaller, which means that a split pattern with a more uniform width is obtained. The results are shown in Table 2 as "LWR (nm)".

  As shown in Table 2 above, a split pattern formed using the positive resist composition of Test Examples 1 to 3 containing an acid diffusion control agent component containing an acid having an acid dissociation constant (pKa) of 3.0 or more The pattern dimensions were fine, and the pattern height and LWR were also good.

DESCRIPTION OF SYMBOLS 1 ... support body, 1P ... 1st resist pattern, 2 ... 1st layer, 3 ... structure, B1 ... layer, 1Pa ... organic developing solution insoluble area | region, 1Pb ... organic developing solution soluble area

Claims (2)

Applying a positive resist composition on a support to form a positive resist film, exposing the positive resist film, and alkali developing to form a first resist pattern;
On the support on which the first resist pattern is formed, a solution containing an acid or a thermal acid generator is applied so as to cover the first resist pattern, and the first resist pattern and this are then Step B of obtaining a structure including a first layer to be coated;
Applying a solution containing an acid diffusion control agent so as to cover the structure B1;
A step C of heating the structure after the step B1 and changing the solubility of the first resist pattern in an organic solvent by the action of the acid generated from the acid or the thermal acid generator;
And D. a step D of forming a split pattern by developing the heated structural body with an organic solvent and removing a region other than the region where the solubility of the first resist pattern in the organic solvent has changed. Forming method,
The positive resist composition contains an acid diffusion control agent,
The resist pattern formation method, wherein the acid diffusion control agent contains an acid having an acid dissociation constant (pKa) of 3.0 or more. The acid diffusion control agent having an acid dissociation constant (pKa) containing 3.0 or more acids, comprising a compound represented by any one of the following general formula (d1-1) ~ (d1-3), claim 1 the resist pattern forming method according to.

[In the general formulas (d1-1) to (d1-3), Rd ^{1 to} Rd ⁴ each independently represent a cyclic group which may have a substituent, or a chain alkyl group which may have a substituent, Or a chain-like alkenyl group which may have a substituent. However, it is assumed that two or more fluorine atoms are 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 ^{m +} is each independently an m-valent organic cation. ]

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