JP7076207B2 - Resist pattern formation method - Google Patents

Description

The present invention relates to a resist pattern forming method.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed, and a development process is performed to form a resist pattern having a predetermined shape on the resist film. The process of performing is performed. A resist material whose exposed portion of the resist film changes to a characteristic that dissolves in a developing solution is called a positive type, and a resist material whose exposed portion of a resist film changes to a characteristic that does not dissolve in a developing solution is called a negative type.
In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, the pattern has been miniaturized due to advances in lithography technology. As a miniaturization method, generally, the wavelength of the exposure light source is shortened (energy is increased). Specifically, in the past, ultraviolet rays typified by g-rays and i-rays were used, but nowadays, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers is being carried out. Further, EUV (extreme ultraviolet), EB (electron beam), X-ray and the like having a shorter wavelength (high energy) than these excimer lasers are also being studied.

The resist material is required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing fine dimensional patterns.
Conventionally, as a resist material satisfying such a requirement, a chemically amplified resist composition containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component that generates an acid by exposure. Is used.
For example, when the developer is an alkaline developer (alkali development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkaline developer is increased by the action of an acid and acid generation. Those containing an agent component are generally used. When a resist film formed by using such a resist composition is selectively exposed at the time of forming a resist pattern, an acid is generated from an acid generator component in an exposed portion, and the action of the acid increases the polarity of the base resin. Then, the exposed portion of the resist film becomes soluble in the alkaline developer. Therefore, alkaline development forms a positive pattern in which the unexposed portion of the resist film remains as a pattern.
On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), when the polarity of the base resin increases, the organic developer is relatively developed. Since the solubility in the liquid is lowered, the unexposed portion of the resist film is dissolved and removed by the organic developing solution, and a negative resist pattern is formed in which the exposed portion of the resist film remains as a pattern. The solvent development process for forming a negative resist pattern in this way is sometimes called a negative development process.

So far, as the base resin of the chemically amplified resist composition, for example, polyhydroxystyrene (PHS) having high transparency with respect to KrF excimer laser (248 nm) and a resin in which the hydroxyl group thereof is protected by an acid dissociative dissolution inhibitory group. (PHS-based resin) has been used. Further, for example, for an ArF excimer laser (193 nm), a resin ((meth) acrylic resin) in which the hydroxyl group in the carboxy group of (meth) acrylic acid is protected by an acid dissociative dissolution inhibitory group has been used (for example,). See Patent Document 1).
The acid dissociative dissolution inhibitory group is represented by a so-called acetal group such as a chain ether group represented by a 1-ethoxyethyl group or a cyclic ether group represented by a tetrahydropyranyl group, and a tert-butyl group. A tertiary alkyl group, a tertiary alkoxycarbonyl group typified by a tert-butoxycarbonyl group and the like are mainly used.

In addition, a wide variety of acid generator components used in the chemically amplified resist composition have been proposed so far, for example, onium salt-based acid generators such as iodonium salt and sulfonium salt, and oxime sulfonate-based. Known acid generators, diazomethane acid generators, nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, disulfonic acid generators and the like.
Among these, onium salt-based acid generators are widely used, and those having onium ions such as triphenylsulfonium in the cation portion are mainly used. As the anion portion of this onium salt-based acid generator, a fluorinated alkyl sulfonic acid ion in which a part or all of the hydrogen atom of the alkyl sulfonic acid ion or its alkyl group is replaced with a fluorine atom or the like is generally used. ing.

By the way, at present, along with the high integration of LSI and the high speed of communication, it is required to increase the memory capacity, and the pattern is rapidly miniaturized. However, although lithography using electron beam or EUV aims to form a fine pattern of several tens of nm, there are still many problems such as low productivity, and there is a limit to the technique by microfabrication.
On the other hand, in addition to miniaturization, the development of a three-dimensional structure device for increasing the capacity of memory by stacking cells is being promoted.

Japanese Patent Application Laid-Open No. 2003-241385

In the manufacture of the above-mentioned three-dimensional structure device, a thick resist film having a higher film thickness than the conventional one, for example, having a film thickness of 7 μm or more is formed on the surface of the workpiece to form a resist pattern. It has a step of performing etching and the like. When a chemically amplified resist composition is used here, the thicker the resist film thickness, the more difficult it becomes to maintain the sensitivity during exposure. When an attempt is made to form a thick-film resist film using a conventional chemically amplified resist composition, there is a problem that a large amount of exposure is required and the sensitivity is lowered. Further, there is a problem that the resolution for development is lowered and it is difficult to obtain a desired resist pattern shape.

The present invention has been made in view of the above circumstances, and exhibits high sensitivity even when forming a thick resist film having a film thickness of 7 μm or more, and forms a pattern having a good shape. An object of the present invention is to provide a method for forming a resist pattern that can be formed.

In order to solve the above problems, the present invention has adopted the following configuration.
That is, in the resist pattern forming method of the present invention, a step (i) of forming a resist film having a thickness of 7 μm or more on a support using a resist composition, a step (ii) of exposing the resist film, and the exposure. A resist pattern forming method comprising a step (iii) of developing a resist film afterwards to form a resist pattern, wherein the resist composition generates an acid by exposure and becomes soluble in a developing solution by the action of the acid. It changes and is polar due to the action of the structural unit (a10) represented by the following general formula (a10-1), the structural unit (a4) containing an acid non-dissociable aliphatic cyclic group, and the action of an acid. It is characterized by containing a structural unit (a1) containing an acid-degradable group and a resin component (A1) having.

［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る。Ｙａ^ｘ１は、単結合又は２価の連結基である。Ｗａ^ｘ１は、（ｎ_ａｘ１＋１）価の芳香族炭化水素基である。ｎ_ａｘ１は、１～３の整数である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or divalent linking group. Wa ^x1 is an aromatic hydrocarbon group having a (n _ax1 + 1) valence. n _ax1 is an integer of 1 to 3. ]

According to the present invention, it is possible to provide a resist pattern forming method that exhibits high sensitivity and can form a pattern having a good shape even when forming a thick resist film having a film thickness of 7 μm or more. can.

In the present specification and claims, "aliphatic" is defined as a relative concept to aromatics and means non-aromatic groups, compounds and the like.
Unless otherwise specified, the "alkyl group" shall include linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The "alkyl halide group" is a group in which a part or all of the hydrogen atom of the alkyl group is substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which a part or all of the hydrogen atom of the alkyl group or the alkylene group is substituted with a fluorine atom.
The “constituent unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
When describing "may have a substituent", a case where a hydrogen atom (-H) is substituted with a monovalent group and a case where a methylene group ( _-CH2- ) is substituted with a divalent group. Including both.
"Exposure" is a concept that includes general irradiation of radiation.

The “constituent unit derived from the acrylic acid ester” means a structural unit formed by cleaving the ethylenic double bond of the acrylic acid ester.
The "acrylic acid ester" is a compound in which the hydrogen atom at the terminal of the carboxy group of acrylic acid (CH ₂ = CH-COOH) is replaced with an organic group.
In the acrylic acid ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α0 ) that replaces the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than the hydrogen atom, for example, an alkyl group having 1 to 5 carbon atoms and a halogenation having 1 to 5 carbon atoms. Examples thereof include an alkyl group. In addition, an itaconic acid diester in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and an α-hydroxyacrylic ester in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group modified with a hydroxyl group thereof are also available. It shall include. The carbon atom at the α-position of the acrylic acid ester is a carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified.
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. Further, the acrylic acid ester and the α-substituted acrylic acid ester may be collectively referred to as “(α-substituted) acrylic acid ester”. Further, acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as α-substituted acrylic acid. In addition, acrylic acid and α-substituted acrylic acid may be collectively referred to as “(α-substituted) acrylic acid”.

"Constituent unit derived from acrylamide" means a structural unit composed by cleavage of the ethylenic double bond of acrylamide.
In acrylamide, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, or one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. The carbon atom at the α-position of acrylamide is a carbon atom to which the carbonyl group of acrylamide is bonded, unless otherwise specified.
As the substituent for substituting the hydrogen atom bonded to the carbon atom at the α-position of acrylamide, the same group as the substituent at the α-position (substituent (R ^α0 )) mentioned as the substituent at the α-position in the α-substituted acrylic acid ester is used. Can be mentioned.

The “constituent unit derived from hydroxystyrene” means a structural unit composed by cleavage of the ethylenic double bond of hydroxystyrene. The “constituent unit derived from the hydroxystyrene derivative” means a structural unit formed by cleaving the ethylenic double bond of the hydroxystyrene derivative.
The term "hydroxystyrene derivative" is a concept including a hydrogen atom at the α-position of hydroxystyrene substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. As those derivatives, the hydrogen atom at the α-position may be substituted with a substituent. The hydrogen atom of the hydroxyl group of hydroxystyrene is substituted with an organic group; even if the hydrogen atom at the α-position is substituted with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group is bonded to a good hydroxystyrene benzene ring. The α-position (carbon atom at the α-position) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.
Examples of the substituent substituting the hydrogen atom at the α-position of hydroxystyrene include the same as those mentioned as the substituent at the α-position in the α-substituted acrylic acid ester.

The "constituent unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative" means a structural unit formed by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The term "vinyl benzoic acid derivative" is a concept including a hydrogen atom at the α-position of vinyl benzoic acid substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. As those derivatives, the hydrogen atom at the α-position may be substituted with a substituent. The hydrogen atom of the carboxy group of vinyl benzoic acid is substituted with an organic group; the hydrogen atom at the α-position is substituted with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. The α-position (carbon atom at the α-position) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.

The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Further, the alkyl halide group as the substituent at the α-position is specifically a group in which a part or all of the hydrogen atom of the above-mentioned "alkyl group as the substituent at the α-position" is substituted with a halogen atom. Be done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferable.
Further, as the hydroxyalkyl group as the substituent at the α-position, specifically, a group in which a part or all of the hydrogen atom of the above-mentioned "alkyl group as the substituent at the α-position" is substituted with a hydroxyl group can be mentioned. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, most preferably 1.

In the present specification and claims, there are some structures represented by chemical formulas in which an asymmetric carbon is present and an enantiomer or a diastereomer may be present. In the case, one formula is used to represent those isomers. These isomers may be used alone or as a mixture.

(Resist pattern forming method)
The resist pattern forming method of the present invention includes a step (i) of forming a resist film having a thickness of 7 μm or more on a support using a resist composition, a step (ii) of exposing the resist film, and after the exposure. It has a step (iii) of developing a resist film to form a resist pattern. In the resist pattern forming method of this aspect, a specific resist composition is selected in step (i).
The resist pattern forming method according to this aspect can be performed as follows, for example.

Step (i):
First, a specific resist composition described later is applied onto the support with a spinner or the like, and a bake (post-apply bake (PAB)) treatment is performed, for example, at 80 to 150 ° C., preferably 100 to 150 ° C. (more preferably). It is applied for 40 to 120 seconds, preferably 60 to 120 seconds (more preferably 80 to 100 seconds) under a temperature condition of more than 100 ° C. and 150 ° C. or lower to form a resist film having a film thickness of 7 μm or more.

Step (ii):
Next, the resist film is selectively exposed by exposure through a mask (mask pattern) on which a predetermined pattern is formed, for example, using an exposure apparatus or the like, and then baked (post-exposure bake (PEB)). )) The treatment is carried out under temperature conditions of, for example, 80 to 150 ° C., preferably 90 to 130 ° C. for 40 to 120 seconds, preferably 60 to 100 seconds.

Step (iii):
Next, the resist film after the exposure is developed. In the case of the alkaline developing process, the developing process is performed using an alkaline developing solution, and in the case of the solvent developing process, a developing solution containing an organic solvent (organic developing solution) is used.
After the development treatment, a rinsing treatment is preferably performed. In the case of the alkaline development process, the rinsing treatment is preferably a water rinse using pure water, and in the case of the solvent development process, it is preferable to use a rinsing solution containing an organic solvent.
In the case of the solvent development process, after the development treatment or the rinsing treatment, a treatment for removing the developing solution or the rinsing solution adhering to the pattern with a supercritical fluid may be performed.

Drying is performed after the development treatment or the rinsing treatment. In some cases, a baking process (post-baking) may be performed after the development process.
In this way, the resist pattern can be formed.

The support is not particularly limited, and conventionally known ones can be used, and examples thereof include a substrate for electronic components and a support having a predetermined wiring pattern formed therein. More specifically, a silicon wafer, a metal substrate such as copper, chromium, iron, or aluminum, a glass substrate, or the like can be mentioned. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold and the like can be used.
Further, the support may be one in which an inorganic film and / or an organic film is provided on the substrate as described above. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC) and an organic film such as a lower organic film in the multilayer resist method.
Here, in the multilayer resist method, at least one layer of an organic film (lower layer organic film) and at least one layer of a resist film (upper layer resist film) are provided on a substrate, and a resist pattern formed on the upper layer resist film is used as a mask. It is a method of patterning an 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 organic film, the resist film can be thinned and a fine pattern having a high aspect ratio can be formed.
The multilayer resist method basically includes a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film. It can be divided into a method of forming a multilayer structure having three or more layers provided with (metal thin film, etc.) (three-layer resist method).

The resist pattern forming method of this embodiment is a useful method for forming a high-thickness resist film, and the thickness of the resist film formed in the step (i) is 7 μm or more.
The film thickness of the resist film formed in the step (i) is more preferably 8 μm or more, particularly preferably 10 μm or more, and the upper limit of the film thickness is substantially 30 μm or less.

The wavelength used for exposure is not particularly limited, and may be ArF excimer laser, KrF excimer laser, F2 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 pattern forming method according to this aspect is a particularly suitable method when the resist film is irradiated with KrF excimer laser light in the step (ii).

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lens at the lowest position 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. This is the exposure method.
As the immersion medium, a solvent having a refractive index 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 such a 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, and a hydrocarbon-based solvent.
Specific examples of the fluorinated inert liquid include a fluorinated compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, those having a boiling point of 70 to 180 ° C., and more preferably those having a boiling point of 80 to 160 ° C. When the fluorine-based inert liquid has a boiling point in the above range, it is preferable because the medium used for immersion can be removed by a simple method after the end of exposure.
As the fluorine-based inert liquid, a perflooloalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perflooloalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
Further, specifically, as the perfluoroalkyl ether compound, perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.) can be mentioned, and as the perfluoroalkylamine compound, perfluorotributylamine (perfluorotributylamine) can be mentioned. Boiling point 174 ° C.) can be mentioned.
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility and the like.

Examples of the alkaline developer used in the developing process in the alkaline developing process include a 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used in the developing process in the solvent developing process may be any known organic solvent as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specific examples thereof include ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, polar solvents such as ether solvents, hydrocarbon solvents and the like.
The ketone solvent is an organic solvent containing CC (= O) -C in its structure. The ester solvent is an organic solvent containing CC (= O) -OC in its structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in its structure. The "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. The nitrile-based solvent is an organic solvent containing a nitrile group in its structure. The amide-based solvent is an organic solvent containing an amide group in its structure. The ether solvent is an organic solvent containing COC in its structure.
Among the organic solvents, there are organic solvents containing a plurality of functional groups that characterize each of the above solvents in the structure, but in that case, the organic solvent corresponds to any solvent type containing the functional groups of the organic solvent. It shall be. For example, diethylene glycol monomethyl ether shall fall under any of the alcohol-based solvents and ether-based solvents in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent which is composed of a hydrocarbon which may be halogenated and has no substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
Among the above, the organic solvent contained in the organic developer is preferably a polar solvent, preferably a ketone solvent, an ester solvent, a nitrile solvent and the like.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexanone, phenylacetone and methylethylketone. , Methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methylamylketone (2-heptanone) and the like. Among these, methylamylketone (2-heptanone) is preferable as the ketone solvent.

Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxy acetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol mono. 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 glycol 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 － Propyl, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, propionic acid Ethyl, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate , Propyl-3-methoxypropionate and the like. Among these, butyl acetate is preferable as the ester solvent.

Examples of the nitrile-based solvent include acetonitrile, propionitril, valeronitrile, butyronitril and the like.

A known additive can be added to the organic developer, if necessary. Examples of the additive include a surfactant. The surfactant is not particularly limited, and for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant can be used. As the surfactant, a nonionic surfactant is preferable, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.% With respect to the total amount of the organic developer. 5% by mass is more preferable.

The developing process can be carried out by a known developing method. For example, a method of immersing a support in a developing solution for a certain period of time (dip method), a method of raising the developing solution on the surface of the support by surface tension and allowing it to stand still for a certain period of time. (Paddle method), spraying the developer on the surface of the support (spray method), applying the developer on the support rotating at a constant speed while scanning the developing solution ejection nozzle. Examples include a method of continuing (dynamic dispensing method).

As the organic solvent contained in the rinse solution used for the rinse treatment after the development process in the solvent development process, for example, among the organic solvents listed as the organic solvents used in the organic developer, those that do not easily dissolve the resist pattern are appropriately selected. Can be used. Usually, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent and an ether solvent is used. Among these, at least one selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent and an amide solvent is preferable, and at least one selected from an alcohol solvent and an ester solvent is more preferable. Alcoholic solvents are preferred, and alcoholic solvents are particularly preferred.
The alcohol solvent used in the rinsing solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples thereof include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol and the like. Be done. Among these, 1-hexanol, 2-heptanol and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be used in combination. Further, it may be used by mixing with an organic solvent other than the above or water. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and further preferably 3% by mass, based on the total amount of the rinsing liquid. The following are particularly preferred.
A known additive can be added to the rinse solution, if necessary. Examples of the additive include a surfactant. Examples of the surfactant include the same as described above, and a nonionic surfactant is preferable, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, preferably 0.01 to 0.5% by mass, based on the total amount of the rinse liquid. % Is more preferable.

The rinsing treatment (cleaning treatment) using the rinsing liquid can be carried out by a known rinsing method. Examples of the rinsing treatment method include a method of continuously spraying the rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in the rinsing liquid for a certain period of time (dip method), and the like. Examples thereof include a method of spraying a rinse liquid on the surface of the support (spray method).

<Resist composition>
In the resist pattern forming method of the present invention described above, a specific resist composition is used in step (i).
Such a specific resist composition generates an acid by exposure, and the solubility in a developing solution is changed by the action of the acid. Examples of this resist composition include embodiments containing a base material component (A) (hereinafter, also referred to as “component (A)”) whose solubility in a developing solution is changed by the action of an acid.

The resist composition of the present embodiment is suitable for forming a resist pattern for exposure with KrF excimer laser light.
Further, the resist composition of the present embodiment is useful as a resist agent for forming a resist film having a high film thickness on a support, and is suitable for forming a resist film having a film thickness of 7 μm or more. be.

When a resist film is formed using the resist composition of the present embodiment and selective exposure is performed to the resist film, an acid is generated in the exposed portion of the resist film, and the component (A) is generated by the action of the acid. While the solubility of the resist film in the developing solution changes, the solubility of the component (A) in the developing solution does not change in the unexposed portion of the resist film, so that the resist film is developed between the exposed portion and the unexposed portion. There is a difference in solubility in the liquid. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and if the resist composition is a negative type, the resist film is not formed. The exposed portion is melted and removed to form a negative resist pattern.

In the present specification, a resist composition in which a resist film exposed portion is melted and removed to form a positive resist pattern is referred to as a positive resist composition, and a negative resist pattern in which a resist film unexposed portion is melted and removed is referred to as a positive resist composition. The resist composition to be formed is referred to as a negative resist composition.
The resist composition of the present embodiment may be a positive resist composition or a negative resist composition.
Further, the resist composition of the present embodiment may be used for an alkaline developing process in which an alkaline developing solution is used for the developing process at the time of forming a resist pattern, and a developing solution (organic developing solution) containing an organic solvent in the developing process. It may be for a solvent developing process using.
That is, the resist composition of the present embodiment is a "positive resist composition for an alkali developing process" that forms a positive resist pattern in an alkali developing process, and is a "solvent developing" that forms a negative resist pattern in a solvent developing process. It is a negative resist composition for processing.

The resist composition of the present embodiment has an acid-generating ability to generate an acid by exposure, and the component (A) may generate an acid by exposure, and is added separately from the component (A). The agent component may generate an acid upon exposure.
Specifically, the resist composition of the embodiment may contain (1) an acid generator component (B) (hereinafter referred to as "(B) component") that generates an acid by exposure; (2) The component (A) may be a component that generates an acid by exposure; the component (3) (A) is a component that generates an acid by exposure and further contains the component (B). May be.
That is, in the case of the above (2) or (3), the component (A) is "a base material component that generates an acid by exposure and whose solubility in a developing solution is changed by the action of the acid". When the component (A) is a base material component that generates an acid by exposure and whose solubility in a developing solution changes due to the action of the acid, the component (A1) described later generates an acid by exposure and the solubility in the developer changes. It is preferably a polymer compound whose solubility in a developing solution changes due to the action of an acid. As such a polymer compound, a copolymer having a structural unit that generates an acid upon exposure can be used. Examples of the structural unit that generates an acid by exposure include known ones.
The resist composition of this embodiment is particularly preferably the case of (1) above.

≪ (A) component ≫
The component (A) is a base material component whose solubility in a developing solution changes due to the action of an acid.
In the present invention, the "base material component" is an organic compound having a film-forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, it becomes easy to form a nano-level resist pattern.
Organic compounds used as base material components are roughly classified into non-polymers and polymers.
As the non-polymer, one having a molecular weight of 500 or more and less than 4000 is usually used. Hereinafter, the term "small molecule compound" means a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, a polymer having a molecular weight of 1000 or more is usually used. Hereinafter, the term "resin", "polymer compound" or "polymer" means a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-equivalent weight average molecular weight by GPC (gel permeation chromatography) shall be used.

The component (A) in the resist composition of the present embodiment contains a resin component (A1) (hereinafter, also referred to as “component (A1)”) whose solubility in a developing solution is changed by the action of an acid.
As the component (A), at least the component (A1) is used, and other high molecular weight compounds and / or low molecular weight compounds may be used in combination with the component (A1).

The component (A1) in the present embodiment includes a structural unit (a10) represented by the general formula (a10-1) described later, a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group, and an acid. It has a structural unit (a1) containing an acid-degradable group whose polarity is increased by the action of the above. The component (A1) may have other structural units, if necessary, in addition to the structural unit (a10), the structural unit (a4), and the structural unit (a1).

In the resist composition of the present embodiment, since the structural unit (a1) contains an acid dissociable group, the polarity of the resin component changes before and after exposure by using the component (A1), and only in the alkaline development process. However, even in the solvent development process, good development contrast can be obtained between the exposed portion and the unexposed portion of the resist film.

When the alkaline developing process is applied, the component (A1) is sparingly soluble in an alkaline developer before exposure. For example, when an acid is generated from the component (B) by exposure, the polarity is increased by the action of the acid. It increases and the solubility in an alkaline developer increases. Therefore, in the formation of the resist pattern, when the resist composition is selectively exposed to the resist film obtained by applying the resist composition on the support, the resist film exposed portion changes from sparingly soluble to alkaline developing solution to soluble. On the other hand, since the unexposed portion of the resist film remains sparingly soluble in alkali, a positive resist pattern is formed by alkaline development.
On the other hand, when a solvent developing process is applied, the component (A1) is highly soluble in an organic developer before exposure, and for example, when an acid is generated from the component (B) by exposure, the action of the acid Increases the polarity and reduces the solubility in an organic developer. Therefore, in the formation of the resist pattern, when the resist composition is selectively exposed to the resist film obtained by applying the resist composition on the support, the resist film exposed portion becomes soluble to sparingly soluble in the organic developing solution. On the other hand, since the unexposed portion of the resist film remains soluble and does not change, a negative resist pattern is formed by developing with an organic developer.

-About the structural unit (a10):
The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

［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る。Ｙａ^ｘ１は、単結合又は２価の連結基である。Ｗａ^ｘ１は、（ｎ_ａｘ１＋１）価の芳香族炭化水素基である。ｎ_ａｘ１は、１～３の整数である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or divalent linking group. Wa ^x1 is an aromatic hydrocarbon group having a (n _ax1 + 1) valence. n _ax1 is an integer of 1 to 3. ]

In the formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms of R 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, or n-. Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms of R is a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable from the viewpoint of industrial availability.

In the formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.
As the divalent linking group in Ya ^x1 , for example, a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom are preferable.

A divalent hydrocarbon group that may have a substituent:
When Ya ^x1 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

An aliphatic hydrocarbon group in Ya ^x1 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, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

... Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and carbon. The number 1 to 4 is more preferable, and the number of carbons 1 to 3 is most preferable.
As the 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- ], tetramethylene group [-(CH ₂ ) _4- ], pentamethylene group [-(CH ₂ ) _5- ] and the like can be mentioned.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -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 -etc. Alkyl methylene groups;- CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -C (CH ₂ ) CH ₃ ) ₂ -CH ₂ -etc. Alkylethylene groups; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ -etc. Alkyltrimethylene groups; -CH (CH ₃ ) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH _2- , −CH ₂ CH (CH ₃ ) CH ₂ CH _2- and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

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

... An aliphatic hydrocarbon group containing a ring in the structure As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group may contain a substituent containing a hetero atom in the ring structure. (A group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, the cyclic fat. Examples thereof include a group in which a group hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same groups 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 may be a polycyclic group or a monocyclic group. As the 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 thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically. Examples thereof include adamantan, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

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, an alkyl halide group, a hydroxyl group, a carbonyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are most preferable.
As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group are more preferable. The methoxy group and the ethoxy group are most preferable.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include a group in which a part or all of the hydrogen atom of the alkyl group is substituted with the halogen atom.
The cyclic aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom as a part of the carbon atom constituting the ring structure. As the substituent containing the heteroatom, —O—, —C (= O) —O—, —S—, —S (= O) _2- , —S (= O) ₂ -O— are preferable.

Aromatic hydrocarbon group in Ya ^x1 The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings. A group obtained by removing two hydrogen atoms from (for example, biphenyl, fluorene, etc.); one of the hydrogen atoms of the group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring. Hydrogen from an aryl group in an arylalkyl group such as a group substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group). A group from which one atom is further removed) and the like can be mentioned. The alkylene group bonded to the aryl group or the heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the aromatic hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are most preferable.
Examples of the alkoxy group, the halogen atom and the alkyl halide group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

-A divalent linking group containing a heteroatom:
When Ya ^x1 is a divalent linking group containing a heteroatom, the preferred linking groups are -O-, -C (= O) -O-, -C (= O)-, and -OC. (= 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-, general formula-Y ²¹ -O-Y ^22- , -Y ²¹ -O-, -Y ^21- C (= O) -O-, -C (= O) -OY ²¹ -,-[Y ²¹ -C (= O) -O] _{m "} -Y ^22- , -Y ²¹ -OC ( = O) -Y ^22- or -Y ²¹ -S (= O) ₂ -O-Y ^22- [In the formula, Y ²¹ and Y ²² each have an independent substituent. It is also a good divalent hydrocarbon group, where O is an oxygen atom and m "is an integer of 0-3. ] And so on.
The divalent linking group containing the hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). )-, The H may be substituted with a substituent such as an alkyl group or an acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
General 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-, -Y ²¹ - ^OC (= O) -Y ^{22- or -Y 21 -} S (= O) ₂ -O-Y ²² -Medium, Y ²¹ and Y ²² are divalent hydrocarbon groups which may independently have a substituent. The divalent hydrocarbon group is mentioned in the description as the divalent linking group. (A divalent hydrocarbon group which may have a substituent) is mentioned.
As ^Y21 , 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 alkyl methylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- , m" is an integer of 0 to 3, preferably an integer of 0 to 2. 0 or 1 is more preferred, and 1 is particularly preferred. That is, the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- is represented by the formula-Y ²¹ -C ⁽ = O) -OY 22-. A group is particularly preferable. Among them, a group represented by the formula- (CH ₂ ) _a' -C (= O) -O- (CH ₂ ) b'-is preferable. In the formula, _a'is 1 to 10 Is an integer of 1 to 8, preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b'is an integer of 1 to 10 and 1 to 8. An integer is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable.

Ya ^x1 includes a single bond, an ester bond [-C (= O) -O-], an ether bond (-O-), -C (= O) -NH-, and a linear or branched alkylene group. , Or a combination thereof, and a single bond is particularly preferable.

In the formula (a10-1), Wa ^x1 is an aromatic hydrocarbon group having a (n _ax1 + 1) valence.
Examples of the aromatic hydrocarbon group in Wa ^x1 include a group obtained by removing (n _ax1 + 1) hydrogen atoms from the aromatic ring. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

In the formula (a10-1), n _ax1 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

Hereinafter, specific examples of the structural units represented by the general formula (a10-1) will be shown.
In the formula below, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a10) contained in the component (A1) may be one kind or two or more kinds.
Among the above, the structural unit (a10) is preferably a structural unit containing a hydroxystyrene skeleton, and particularly preferably a structural unit represented by the following general formula (a10-1-0).

［式中、Ｒ^ｓｔは、水素原子又はメチル基を表す。ｍ_０１は１～３の整数を表す。］

[In the formula, R ^st represents a hydrogen atom or a methyl group. m ₀₁ represents an integer of 1 to 3. ]

The ratio of the constituent unit (a10) in the component (A1) is preferably 40 to 80 mol%, preferably 45 to 75 mol%, based on the total (100 mol%) of all the constituent units constituting the component (A1). Is more preferable, and 50 to 70 mol% is particularly preferable.
By setting the ratio of the structural unit (a10) to be equal to or higher than the lower limit of the preferred range, the sensitivity, development characteristics, effect of suppressing the occurrence of defects, etc. are further improved, while the ratio is set to be equal to or lower than the upper limit of the preferred range. This further improves lithography characteristics such as dimensional uniformity.

-About the structural unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociative aliphatic cyclic group.
Since the component (A1) has a structural unit (a4), the light transmittance of the resist film is enhanced as compared with the case where the component has a structural unit containing an aromatic cyclic group. Further, the dry etching resistance of the formed resist pattern is improved, and in addition, the hydrophobicity of the component (A) is enhanced. The improvement of hydrophobicity contributes to the improvement of resolution, resist pattern shape, etc., particularly in the case of resist pattern formation by a solvent developing process.
The "acid non-dissociative cyclic group" in the structural unit (a4) is the acid when an acid is generated in the resist composition by exposure (for example, when an acid is generated from the component (B) described later). It is a cyclic group that remains in the constituent unit as it is without dissociation even if it acts.

The acid non-dissociable aliphatic cyclic group in the structural unit (a4) may be a monocyclic group, a polycyclic group, or a monocyclic group, and is preferable.
As the monocyclic group here, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. As the monocycloalkane, those having 3 to 8 carbon atoms are more preferable, those having 5 to 8 carbon atoms are further preferable, and specific examples thereof include cyclopentane, cyclohexane and cyclooctane. As the polycyclic group here, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically, adamantane. Examples thereof include norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The monocyclic group and the polycyclic group may each have, for example, a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

Examples of the structural unit (a4) include 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, a structural unit derived from acrylamide, and the like. 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.

A specific example of the structural unit (a4) is shown below.
In the formula below, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a4) contained in the component (A1) may be one kind or two or more kinds.
Among the above, the structural unit (a4) is preferably a structural unit that is acid non-dissociative and contains a monocyclic aliphatic cyclic group, and any of the above chemical formulas (a4-7) to (a4-10). At least one selected from the group consisting of the structural units represented by is more preferable.

The proportion of the constituent unit (a4) in the component (A1) is preferably 1 to 50 mol% with respect to the total (100 mol%) of all the constituent units constituting the component (A1), 2 to 2 to. 50 mol% is more preferable, and 5 to 45 mol% is even more preferable.
By setting the ratio of the structural unit (a4) to be equal to or higher than the lower limit of the above-mentioned preferable range, the light transmittance of the resist film is further enhanced, and the sensitivity and the resolution are further improved. On the other hand, by setting the value to or less than the upper limit of the above-mentioned preferable range, it becomes easy to balance with other constituent units.

-About the structural 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.
An "acid-degradable group" is a group having an acid-degradable property in which at least a part of the bonds in the structure of the acid-degradable group can be cleaved by the action of an acid.
Examples of the acid-degradable group whose polarity is increased by the action of an acid include a group which is decomposed by the action of an acid to form a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (-SO _3H ) and the like. Among these, a polar group containing —OH in the structure (hereinafter, may be referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specifically, the acid-degradable group includes a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).
Here, the "acid dissociative group" is (i) a group having an acid dissociative property in which the bond between the acid dissociative group and an atom adjacent to the acid dissociative group can be cleaved by the action of an acid. Alternatively, (ii) after a part of the bond is cleaved by the action of the acid, a further decarbonation reaction occurs, so that the bond between the acid dissociative group and the atom adjacent to the acid dissociative group is cleaved. It refers to both the basis to be obtained.
The acid dissociative group constituting the acid-degradable group needs to be a group having a lower polarity than the polar group produced by the dissociation of the acid dissociative group, whereby the acid dissociative group is affected by the action of the acid. When is dissociated, a polar group having a higher polarity than the acid dissociative group is generated and the polarity is increased. As a result, the polarity of the entire (A1) component increases. As the polarity increases, the solubility in the developer changes relatively, the solubility increases when the developer is an alkaline developer, and the solubility increases when the developer is an organic developer. Decrease.

Examples of the acid dissociable group include those proposed as an acid dissociable group of a base resin for a chemically amplified resist composition.
Specifically, as the acid dissociative group of the base resin for the chemically amplified resist composition, the "acetal type acid dissociative group" and the "tertiary alkyl ester type acid dissociative group" described below are described below. Examples include "group" and "tertiary alkyloxycarbonyl acid dissociable group".

-Acetal-type acid dissociative group:
Among the polar groups, the acid dissociable group that protects the carboxy group or the hydroxyl group is, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal type acid dissociative group”). There are times.).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子又はアルキル基であり、Ｒａ’^３は炭化水素基であって、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。］

[In the formula, ^Ra'1 and ^Ra'2 are hydrogen atoms or alkyl groups, ^Ra'3 is ^a hydrocarbon group, and ^Ra'3 is bonded to either Ra'1 or ^Ra'2 to form a ring. May be formed. ]

In the formula (a1-r-1), it is preferable that at ^{least one} of Ra'1 and Ra'2 is a hydrogen atom, and it is more preferable that both are hydrogen atoms.
When ^Ra'1 or ^Ra'2 is an alkyl group, the alkyl group includes the alkyl group mentioned as a substituent that may be bonded to the carbon atom at the α-position in the above description of the α-substituted acrylic acid ester. The same can be mentioned, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group and the like can be mentioned, and the methyl group or the ethyl group can be mentioned. More preferably, a methyl group is particularly preferable.

In the formula (a1-r-1), examples of the hydrocarbon group of ^Ra'3 include a linear or branched alkyl group or a cyclic hydrocarbon group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group and the like. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

The branched-chain alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group and the like, and an isopropyl group is preferable.

When ^Ra'3 is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically. Examples include adamantan, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group of ^Ra'3 is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, as the aromatic hydrocarbon group in ^Ra'3 , a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle; two or more aromatic rings. A group obtained by removing one hydrogen atom from an aromatic compound (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or the aromatic heterocycle is substituted with an alkylene group (for example, a benzyl group). , Penetyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group and other arylalkyl groups) and the like. The carbon number of the alkylene group bonded to the aromatic hydrocarbon ring or the aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

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

-A tertiary alkyl ester type acid dissociative group:
Among the above polar groups, examples of the acid dissociative group that protects the carboxy group include an acid dissociative group represented by the following general formula (a1-r-2).
Of the acid dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may be hereinafter referred to as "tertiary alkyl ester type acid dissociable groups" for convenience. ..

［式中、Ｒａ’^４～Ｒａ’^６はそれぞれ炭化水素基であって、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。］

[In the formula, ^Ra'4 to ^Ra'6 are hydrocarbon groups, respectively, and ^Ra'5 and ^Ra'6 may be bonded to each other to form a ring. ]

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

［式中、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。］

[In the formula, Ra'10 is an alkyl group having 1 to ¹⁰ carbon atoms, ^Ra'11 is a group forming an aliphatic cyclic group together with a carbon atom to which ^Ra'10 is bonded, and ^Ra'12 to ^Ra'14 are groups, respectively. Independently indicates a hydrocarbon group. ]

In the formula (a1-r2-1), the alkyl group having 1 to ¹⁰ carbon atoms of Ra'10 is mentioned as the linear or branched alkyl group of ^Ra'3 in the formula (a1-r-1). Groups are preferred. In the formula (a1-r2-1), the aliphatic cyclic group formed together with the carbon atom to which ^Ra'11 and ^Ra'10 are bonded is the monocyclic group of ^Ra'3 in the formula (a1-r-1). Alternatively, the group listed as the aliphatic hydrocarbon group which is a polycyclic group is preferable, and the group listed as the aliphatic hydrocarbon group which is a monocyclic group is more preferable.

In the formula (a1-r2-2), ^Ra'12 and ^Ra'14 are preferably alkyl groups having 1 to 10 carbon atoms independently, and the alkyl groups are in the formula (a1-r-1). The group listed as the linear or branched alkyl group of ^Ra'3 is more preferable, the linear alkyl group having 1 to 5 carbon atoms is more preferable, and the methyl group or the ethyl group is particularly preferable. preferable.
In the formula (a1-r2-2), ^Ra'13 is a linear or branched alkyl group, monocyclic group exemplified as the hydrocarbon group of ^Ra'3 in the formula (a1-r-1). Alternatively, it is preferably an aliphatic hydrocarbon group which is a polycyclic group. Among these, the group mentioned as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of ^Ra'3 is more preferable.

Specific examples of the group represented by the above formula (a1-r2-1) are given below. * Indicates a bond (hereinafter the same in the present specification).

Specific examples of the group represented by the above formula (a1-r2-2) are given below.

・ Tertiary alkyloxycarbonylic acid dissociative group:
Among the polar groups, the acid dissociable group that protects the hydroxyl group is, for example, an acid dissociative group represented by the following general formula (a1-r-3) (hereinafter, for convenience, “tertiary alkyloxycarbonylic acid dissociative group”. ") Can be mentioned.

［式中、Ｒａ’^７～Ｒａ’^９はそれぞれアルキル基である。］

[In the formula, ^Ra'7 to ^Ra'9 are alkyl groups, respectively. ]

In the formula (a1-r-3), ^Ra'7 to ^Ra'9 are preferably alkyl groups having 1 to 5 carbon atoms, respectively, and more preferably 1 to 3 carbon atoms.
The total carbon number of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

Among the above, the acid-degradable group in the constituent unit (a1) is preferably a group containing an alicyclic group because it is more degradable by the action of an acid, and an acid dissociable group containing an alicyclic group. A group in which a polar group (carboxy group, hydroxyl group, amino group, sulfo group, etc.) is protected is more preferable. Among these, the acid-decomposable group in the structural unit (a1) is represented by the above general formula (a1-r2-1) because the resolution is improved and a pattern having a better shape is likely to be formed. A group containing an acid dissociative group is preferable, and a group containing an acid dissociative group represented by the following general formula (a1-r2-11) is more preferable.

［式中、Ｒａ’^１０は、炭素数１～１０の炭化水素基である。Ｒａ”^１１は、Ｒａ’^１０が結合した炭素原子と共に単環式の脂肪族環式基を形成する基である。＊は結合手である。］

[In the formula, Ra'10 is a hydrocarbon group having 1 to ¹⁰ carbon atoms. Ra " ¹¹ is a group that forms a monocyclic aliphatic cyclic group together with the carbon atom to which Ra ^'10 is bonded. * Is a bond.]

In the formula (a1-r2-11), the alkyl group having 1 to ¹⁰ carbon atoms of Ra'10 is mentioned as the linear or branched alkyl group of ^Ra'3 in the formula (a1-r-1). Groups are preferred.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group and the like. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched-chain alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group and the like, and an isopropyl group is preferable.

In the formula (a1-r2-11), the aliphatic cyclic group formed together with the carbon atom to which Ra " ¹¹ and ^Ra'10 are bonded is the monocyclic group of ^Ra'3 in the formula (a1-r-1). The group listed as the aliphatic hydrocarbon group is preferable.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

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, a structural unit derived from acrylamide, hydroxystyrene or hydroxy. -C (= O) of the structural unit in which at least a part of the hydrogen atom in the hydroxyl group of the structural unit derived from the styrene derivative is protected by an acid dissociative group, vinyl benzoic acid or the structural unit derived from the vinyl benzoic acid derivative. Examples thereof include structural units in which at least a part of hydrogen atoms in -OH is protected by an acid dissociative group.

Among the above, the structural unit (a1) is preferably 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.
Preferred specific examples of such a structural unit (a1) include a structural unit represented by the following general formula (a1-1) or general formula (a1-2).

［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る。Ｖａ^１はエーテル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は上記式（ａ１－ｒ－１）又は（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は上記式（ａ１－ｒ－１）又は（ａ１－ｒ－３）で表される酸解離性基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond, n _a1 is 0 to 2, and Ra ¹ is the above formula (a1-r-1) or (a1-r-2). It is an acid dissociable group represented by. Wa ¹ is a n _a2 + 1 valent hydrocarbon group, _{na 2} is 1 to 3, and Ra ² is an acid dissociative group represented by the above formula (a1-r-1) or (a1-r-3). It is the basis. ]

In the above formula (a1-1), the alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group or an ethyl group. , Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable from the viewpoint of industrial availability.

In the above formula (a1-1), the divalent hydrocarbon group in Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specifically, the aliphatic hydrocarbon group includes a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ -(CH ₂ ) _3- ], tetramethylene group [-(CH ₂ ) _4- ], pentamethylene group [-(CH ₂ ) _5- ] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -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 -etc. Alkyl methylene groups;- CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -C (CH ₂ ) CH ₃ ) ₂ -CH ₂ -etc. Alkylethylene groups; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ -etc. Alkyltrimethylene groups; -CH (CH ₃ ) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH _2- , −CH ₂ CH (CH ₃ ) CH ₂ CH _2- and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

As the aliphatic hydrocarbon group containing a ring in the structure, an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from the alicyclic hydrocarbon ring) and an alicyclic hydrocarbon group are linear or branched. Examples thereof include a group bonded to the terminal of a chain-shaped aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group.
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 a polycyclic type or a monocyclic type. As the 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 thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically adamantan. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. .. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are heterogeneous. Examples thereof include aromatic heterocycles substituted with atoms. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group). ) Is a group in which one of the hydrogen atoms is substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group and the like. A group in which one hydrogen atom is further removed from the aryl group in the group) and the like can be mentioned. The carbon number of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the above formula (a1-2), the _na2 + 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, and may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and a linear or branched aliphatic hydrocarbon group. Examples thereof include a group combined with an aliphatic hydrocarbon group containing a ring in the structure.
_{The na2} + 1 valence is preferably 2 to 4 valences, more preferably 2 or 3 valences.

Specific examples of the structural units represented by the above formula (a1-1) are shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

Specific examples of the structural units represented by the above formula (a1-2) are shown below.

As the structural unit (a1), the structural unit represented by the above general formula (a1-1) is more preferable, and among these, the structural unit represented by the general formula (a1-1) is used. A structural unit in which Ra ¹ is an acid dissociative group represented by the above formula (a1-r2-11) is particularly preferable.

The structural unit (a1) contained in the component (A1) may be one kind or two or more kinds.
The ratio of the constituent unit (a1) in the component (A1) is preferably 5 to 20 mol%, more preferably 7 to 20 mol%, based on all the constituent units (100 mol%) constituting the component (A1). 10 to 20 mol% is more preferable.
By setting the ratio of the structural unit (a1) to be equal to or higher than the lower limit of the above-mentioned preferable range, a resist pattern can be easily obtained, the resolution is further improved, and a pattern having a good shape is easily formed. Become. Further, by setting the value to the upper limit or less, it is possible to balance with other constituent units.

・ About other structural units:
The component (A1) may have other structural units, if necessary, in addition to the structural unit (a10), the structural unit (a4), and the structural unit (a1).
As other structural units, for example, a structural unit (a2) containing a lactone-containing cyclic group, a _—SO2 -containing cyclic group or a carbonate-containing cyclic group; a structural unit containing a polar group-containing aliphatic hydrocarbon group (a3). ) (However, those corresponding to the constituent unit (a1) or the constituent unit (a2) are excluded); the constituent unit derived from styrene or a derivative thereof can be mentioned.

・ ・ Structural unit (a2)
The component (A1) contains a lactone-containing cyclic group, a _—SO2 -containing cyclic group or a carbonate, as required, in addition to the structural unit (a10), the structural unit (a4) and the structural unit (a1). It may have a structural unit (a2) including a cyclic group.
The lactone-containing cyclic group, _-SO2 -containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) adheres to the substrate of the resist film when the component (A1) is used for forming the resist film. It is effective in enhancing sex. Further, by having the structural unit (a2), in the alkaline developing process, the solubility of the resist film in the alkaline developer is enhanced at the time of development.

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (= O) —in its ring skeleton. The lactone ring is counted as the first ring, and when it has only a lactone ring, it is called 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.
As the lactone-containing cyclic group in the structural unit (a2), any one can be used without particular limitation. Specifically, the groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

［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又はシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基である。Ａ”は酸素原子（－Ｏ－）もしくは硫黄原子（－Ｓ－）を含んでいてもよい炭素数１～５のアルキレン基、酸素原子又は硫黄原子である。ｎ’は０～２の整数であり、ｍ’は０又は１である。］

[In the formula, ^Ra'21 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano. Group; R "is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ -containing cyclic group. A" is an oxygen atom (-O-) or a sulfur atom. It is an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom which may contain (—S—). n'is an integer of 0 to 2 and m'is 0 or 1. ]

In the formulas (a2-r-1) to (a2-r-7), the alkyl group in ^Ra'21 is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
As the alkoxy group in ^Ra'21 , an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, the group in which the alkyl group mentioned as the alkyl group in ^Ra'21 and the oxygen atom (—O—) are linked can be mentioned.
Examples of the halogen atom in ^Ra'21 include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
Examples of the alkyl halide group in ^Ra'21 include a group in which a part or all of the hydrogen atom of the alkyl group in ^Ra'21 is replaced with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In -COOR "and -OC (= O) R" in Ra ^'21 , R "is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or _-SO2 -containing cyclic group. Is.
The alkyl group in "R" may be linear, branched or cyclic, and the number of carbon atoms is preferably 1 to 15.
When R "is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R "is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and even more preferably 5 to 10 carbon atoms. Specifically, a fluorine atom. Alternatively, a group obtained by removing one or more hydrogen atoms from a monocycloalkane that may or may not be substituted with a fluorinated alkyl group; a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. Examples thereof include a group obtained by removing one or more hydrogen atoms from the group. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane; Examples thereof include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as cyclodecane and tetracyclododecane.
Examples of the lactone-containing cyclic group in "R" include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group in "R" is the same as the carbonate-containing cyclic group described later, and specifically, the groups represented by the general formulas (ax3-r-1) to (ax3-r-3), respectively. Can be mentioned.
The _—SO2 -containing cyclic group in R ”is the same as the _−SO2 -containing cyclic group described later, and specifically, the general formulas (a5-r-1) to (a5-r-4). The groups represented by are listed below.
The hydroxyalkyl group in ^Ra'21 is preferably one having 1 to 6 carbon atoms, and specific examples thereof include a group in which at least one hydrogen atom of the alkyl group in ^Ra'21 is substituted with a hydroxyl group. ..

In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A "is a linear or branched alkylene group. An alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include the terminal or carbon of the alkylene group. Examples include groups with -O- or -S- intervening between atoms, such as -O-CH _2- , -CH ₂ -O-CH _2- , -S-CH _2- , -CH ₂ -SCH. ₂ − and the like can be mentioned. As A ”, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

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

The "-SO ₂ -containing cyclic group" refers to a cyclic group containing a ring containing -SO _2- in its ring skeleton, and specifically, the sulfur atom (S) in -SO _2- A cyclic group that forms part of the cyclic skeleton of the cyclic group. A ring containing -SO _2- in its ring skeleton is counted as the first ring, and if it is only the ring, it is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of its structure. It is called. -SO ₂ -The contained cyclic group may be a monocyclic group or a polycyclic group.
-SO ₂ -containing cyclic groups are particularly cyclic groups containing -O-SO ₂ -in their cyclic skeleton, that is, -OS- in -O-SO _2- is part of the cyclic skeleton. It is preferable that it is a cyclic group containing a sultone ring forming the above.
-SO ₂ -Containing cyclic groups include, more specifically, groups represented by the following general formulas (a5-r-1) to (a5-r-4), respectively.

［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又はシアノ基である。Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基である。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、酸素原子又は硫黄原子である。ｎ’は０～２の整数である。］

[In the formula, ^Ra'51 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano. It is the basis. R "is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a _-SO2 -containing cyclic group. A" may contain an oxygen atom or a sulfur atom and has 1 carbon atom. ~ 5 alkylene groups, oxygen atoms or sulfur atoms. n'is an integer of 0 to 2. ]

In the general formulas (a5-r-1) to (a5-r-2), A "is a general formula (a2-r-2), (a2-r-3), (a2-r-5). It is the same as A "inside.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR ", -OC (= O) R", and hydroxyalkyl group in Ra ^'51 are the above-mentioned general formulas (a2-r-1) to (1), respectively. The same as those mentioned in the description of ^Ra'21 in a2-r-7) can be mentioned.
Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are given below. "Ac" in the formula indicates an acetyl group.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (= O) —O— in its cyclic skeleton. The carbonate ring is counted as the first ring, and when it has only a carbonate ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
As the carbonate ring-containing cyclic group, any one can be used without particular limitation. Specifically, the 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又はシアノ基である。Ｒ”は、水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基である。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、酸素原子又は硫黄原子である。ｐ’は０～３の整数であり、ｑ’は０又は１である。］

[In the formula, ^Ra'x31 are independently hydrogen atom, alkyl group, alkoxy group, halogen atom, alkyl halide group, hydroxyl group, -COOR ", -OC (= O) R", hydroxyalkyl group or cyano. It is the basis. R "is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a _-SO2 -containing cyclic group. A" is the number of carbon atoms which may contain an oxygen atom or a sulfur atom. It is an alkylene group of 1 to 5, an oxygen atom or a sulfur atom. p'is an integer from 0 to 3, and q'is 0 or 1. ]

In the general formulas (ax3-r-2) to (ax3-r-3), A "is a general formula (a2-r-2), (a2-r-3), (a2-r-5). It is the same as A "inside.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR ", -OC (= O) R", and hydroxyalkyl group in Ra ^'31 are the above-mentioned general formulas (a2-r-1) to (1), respectively. The same as those mentioned in the description of ^Ra'21 in a2-r-7) can be mentioned.
Specific examples of the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are given below.

As the structural unit (a2), 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.
A preferable specific example of the structural unit (a2) is a structural unit represented by the following general formula (a2-1).

［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る。Ｙａ^２１は、単結合又は２価の連結基である。Ｌａ^２１は－Ｏ－、－ＣＯＯ－、－ＣＯＮ（Ｒ’）－、－ＯＣＯ－、－ＣＯＮＨＣＯ－又は－ＣＯＮＨＣＳ－であり、Ｒ’は水素原子又はメチル基を示す。但し、Ｌａ^２１が－Ｏ－の場合、Ｙａ^２１は－ＣＯ－にはならない。Ｒａ^２１は、ラクトン含有環式基、－ＳＯ_２－含有環式基又はカーボネート含有環式基である。］

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

In the formula (a2-1), R is the same as described above.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable from the viewpoint of industrial availability.

In the above formula (a2-1), the divalent linking group of Ya ²¹ is not particularly limited, but is a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom. Etc. are mentioned as suitable ones.

Examples of the divalent hydrocarbon group in Ya ²¹ include the same groups as those mentioned in the description of the divalent hydrocarbon group in Va ¹ in the above-mentioned formula (a1-1). Examples of the substituent that the divalent hydrocarbon group in Ya ²¹ may have include an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a halogen atom, an alkyl halide group having 1 to 5 carbon atoms, and a hydroxyl group. , A carbonyl group and the like.

Preferred divalent linking groups containing a heteroatom in Ya ²¹ are, for example, —O—, —C (= O) —O—, —C (= O) −, —OC (= 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-, general 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- , -Y ²¹ -OC (= O) -Y ²² -or -Y ²¹ -S (= O) ₂ -O-Y ²² -group [In the formula, Y ²¹ and Y ²² may each have an independent substituent 2 It is a valent hydrocarbon group, O is an oxygen atom, and m "is an integer of 0 to 3. ] And so on.
The divalent linking group containing the hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). In the case of −, the H may be substituted with a substituent such as an alkyl group or an acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
General 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-, -Y ²¹ - ^OC (= O) -Y ^{22- or -Y 21 -} S (= O) ₂ -O-Y ²² -Medium, Y ²¹ and Y ²² are divalent hydrocarbon groups which may independently have a substituent. The divalent hydrocarbon group is mentioned in the description as the divalent linking group. (A divalent hydrocarbon group which may have a substituent) is mentioned.
As ^Y21 , 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 alkyl methylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- , m" is an integer of 0 to 3, preferably an integer of 0 to 2, and 0. Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- is represented by the formula-Y ²¹ -C ⁽ = O) -OY 22-. A group is particularly preferable. Among them, a group represented by the formula- (CH ₂ ) _a' -C (= O) -O- (CH ₂ ) b'-is preferable. In the formula, _a'is 1 to 1 to. It is an integer of 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 and 1 to 8. Is preferred, an integer of 1 to 5 is more preferred, 1 or 2 is even more preferred, and 1 is most preferred.

The Ya ²¹ is preferably a single bond, an ester bond [-C (= O) -O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof. ..

In the formula (a2-1), La ²¹ is -O-, -COO-, -CON (R')-, -OCO-, -CONHCO- or -CONHCS-.
R'indicates a hydrogen atom or a methyl group.
However, when La ²¹ is -O-, Ya ²¹ is not -CO-.

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, a _—SO2 -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, _-SO2 -containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ are represented by the above-mentioned general formulas (a2-r-1) to (a2-r-7), respectively. The groups to be represented, the groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively, and the groups represented by the general formulas (ax3-r-1) to (ax3-r-3), respectively. Groups are preferred.
Among them, Ra ²¹ is preferably a lactone-containing cyclic group or a _—SO2 -containing cyclic group, and the general formulas (a2-r-1), (a2-r-2), (a2-r-6) or The groups represented by (a5-r-1) are more preferable. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r- One of the groups represented by lc-6-1), (r-sl-1-1), and (r-sl-1-18) is more preferable.

The structural unit (a2) contained in the component (A1) may be one kind or two or more kinds.
When the component (A1) has a constituent unit (a2), the ratio of the constituent unit (a2) is 1 to 80 mol% with respect to the total (100 mol%) of all the constituent units constituting the (A1) component. It is preferably 3 to 70 mol%, more preferably 5 to 60 mol%, still more preferably 10 to 50 mol%.
When the ratio of the structural unit (a2) is not less than the lower limit of the preferable range, the effect of containing the constitutional unit (a2) can be sufficiently obtained, while it is not more than the upper limit of the preferable range. And other structural units can be balanced, and various lithography characteristics and pattern shapes are improved.

・ ・ Structural unit (a3)
The component (A1) has a constituent unit (a10), a constituent unit (a4), and a constituent unit (a3) containing a polar group-containing aliphatic hydrocarbon group, if necessary, in addition to the constituent unit (a10), the constituent unit (a4), and the constituent unit (a1). It may be used (however, excluding those corresponding to any of the above-mentioned structural unit (a0), structural unit (a1), and structural unit (a2)).
Since the component (A1) has the constituent unit (a3), the hydrophilicity of the component (A) is increased, which contributes to the improvement of the resolution.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, a hydroxyalkyl group in which a part of the hydrogen atom of the alkyl group is replaced with a fluorine atom, and the like, and a hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected and used, for example, from a large number of proposed resins for resist compositions for ArF excimer lasers. 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 the hydrogen atom of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom. Is more preferable. Examples of the polycyclic group include a group obtained by removing two or more hydrogen atoms from a bicycloalkane, a tricycloalkane, a tetracycloalkane, or the like. Specific examples thereof include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are a group in which two or more hydrogen atoms are removed from adamantan, a group in which two or more hydrogen atoms are removed from norbornan, and a group in which two or more hydrogen atoms are removed from tetracyclododecane. Industrially preferable.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any 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 a polar group-containing aliphatic hydrocarbon group is used. Containing structural 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 the hydroxyethyl ester of acrylic acid. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), and the formula ( The structural unit represented by a3-3) is preferably mentioned.

［式中、Ｒは前記と同じであり、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 the formula, R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t'is an integer of 1 to 3, and l is an integer of 1 to 5. And s is an integer of 1 to 3. ]

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

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

In the formula (a3-3), t'is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to 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 one type or two or more types.
When the component (A1) has a constituent unit (a3), the ratio of the constituent unit (a3) is 1 to 50 mol% with respect to the total (100 mol%) of all the constituent units constituting the component (A1). It is preferably 3 to 40 mol%, more preferably 5 to 30 mol%, and particularly preferably 10 to 30 mol%.
By setting the ratio of the structural unit (a3) to a preferable lower limit value or more, the resolution is further enhanced in the resist pattern formation. On the other hand, when the value is not more than the preferable upper limit value, it becomes easy to balance with other constituent units.

.. Constituent unit derived from styrene or its derivative (constituent unit (st))
The term "styrene" includes styrene and those in which the hydrogen atom at the α-position of styrene is substituted with a substituent such as an alkyl group or an alkyl halide group. Examples of the alkyl group as the substituent here include an alkyl group having 1 to 5 carbon atoms, and examples of the halogenated alkyl group as the substituent include an alkyl halide group having 1 to 5 carbon atoms.
Examples of the "styrene derivative" include those in which a substituent is bonded to a benzene ring of styrene in which a hydrogen atom at the α-position may be substituted with a substituent.
The α-position (carbon atom at the α-position) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.
“Constituent unit derived from styrene” and “constituent 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 structural unit (st) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a constituent unit (st), the ratio of the constituent unit (st) is 1 to 30 mol% with respect to the total (100 mol%) of all the constituent units constituting the (A1) component. It is preferably 3 to 20 mol%, and more preferably 3 to 20 mol%.

In the resist composition of the present embodiment, the resin component which is the component (A1) has a structural unit (a10), a structural unit (a4), and a structural unit (a1), and one kind of polymer is used alone. It may be used in combination of two or more kinds.
Preferred (A1) components include a copolymer having a constituent unit (a10), a constituent unit (a4), and a constituent unit (a1), among which the constituent unit (a10) and the constituent unit (a4) are configured. A copolymer composed of the unit (a1) is particularly preferable.

The weight average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography (GPC)) of the component (A1) is preferably 5000 to 30000, more preferably 6000 to 25000, and even more preferably 10000 to 20000.
When the Mw of the component (A1) is not more than the upper limit of the above-mentioned preferable range, it becomes easy to prevent the viscosity of the resist composition from becoming too high. In addition, if it has sufficient solubility in a resist solvent to be used as a resist and is at least the lower limit of the above-mentioned preferable range, a high-thickness resist film is easily formed. In addition, the dry etching resistance and the cross-sectional shape of the resist pattern are improved.
The dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.5 to 2.5. .. Mn indicates a number average molecular weight.

The component (A1) includes, for example, a monomer for inducing a structural unit (a10) (a monomer in which at least a part of hydrogen atoms in a hydroxyl group bonded to a benzene ring is protected), a monomer for inducing a structural unit (a4), and a monomer. A monomer for inducing the structural unit (a1) and, if necessary, a monomer for inducing other structural units are dissolved in a polymerization solvent, wherein, for example, azobisisobutyronitrile (AIBN) and dimethyl azobisisobutyrate (for example). It can be produced by adding a radical polymerization initiator such as V-601) to polymerize, and then carrying out a deprotection reaction.
At the time of polymerization, for example, by using a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C (CF ₃ ) ₂ -OH in combination, -C (CF ₃ ) is used at the end. ₂ -OH groups may be introduced. In this way, the copolymer in which the hydroxyalkyl group in which a part of the hydrogen atom of the alkyl group is replaced with the fluorine atom is introduced can reduce development defects and LER (line edge roughness: non-uniform unevenness of the line side wall). It is effective in reducing the amount of hydrogen.

As the component (A1) contained in the resist composition, one kind may be used alone, or two or more kinds may be used in combination.
The ratio of the component (A1) to the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 75% by mass or more, and 100% by mass with respect to the total mass of the component (A). May be. When the ratio of the component (A1) is equal to or higher than the lower limit of the above-mentioned preferable range, the sensitivity is improved, the resolution is excellent, the dimensional uniformity (CDU) in the support surface (Shot) and other lithography characteristics are excellent. It becomes easy to form a resist pattern having a different shape.

The component (A) in the resist composition of the present embodiment is a resin component whose solubility in a developing solution is changed by the action of an acid, and may contain a resin component other than the component (A1).
The content of the component (A) in the resist composition of the present embodiment may be appropriately adjusted according to the resist film thickness to be formed and the like.

≪Other ingredients≫
The resist composition of the present embodiment may further contain other components other than the component (A) in addition to the component (A) described above. Examples of other components include the following components (B), (D), (E), (F), and (S).

-Regarding the acid generator component (B) The resist composition of the present embodiment may further contain an acid generator component (hereinafter referred to as "(B) component") in addition to the component (A).
The component (B) is not particularly limited, and those previously proposed as an acid generator for a chemically amplified resist can be used.
Examples of such an acid generator include onium salt-based acid generators such as iodonium salt and sulfonium salt, oxime sulfonate-based acid generators; bisalkyl or bisarylsulfonyldiazomethanes, and diazomethane-based poly (bissulfonyl) diazomethanes. Acid generators; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, disulfon-based acid generators, and various other substances can be mentioned. Of these, it is preferable to use an onium salt-based acid generator.

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

［式中、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、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^１０２はフッ素原子又は炭素数１～５のフッ素化アルキル基である。Ｙ^１０１は単結合又は酸素原子を含む２価の連結基である。Ｖ^１０１～Ｖ^１０３はそれぞれ独立に単結合、アルキレン基又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又は酸素原子である。Ｌ^１０３～Ｌ^１０５はそれぞれ独立に単結合、－ＣＯ－又は－ＳＯ_２－である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[In the formula, R ¹⁰¹ and R ¹⁰⁴ to R ¹⁰⁸ each have a cyclic group which may independently have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group that may be present. R ¹⁰⁴ and R ¹⁰⁵ may be coupled to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ are independently single bonds, alkylene groups or fluorinated alkylene groups, respectively. L ¹⁰¹ to L ¹⁰² are independently single bonds or oxygen atoms, respectively. L ¹⁰³ to L ¹⁰⁵ are independently single bonds, -CO- or -SO _2- . m is an integer of 1 or more, and M'm ⁺ is an m-valent onium cation. ]

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

Cyclic group which may have a substituent:
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. Aliphatic hydrocarbon groups mean hydrocarbon groups that do not have aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aromatic hydrocarbon group in R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and 6 to 6 carbon atoms. 10 is the most preferable. However, the carbon number does not include the carbon number in the substituent.
Specifically, as the aromatic ring of the aromatic hydrocarbon group in R ¹⁰¹ , benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of carbon atoms constituting these aromatic rings was substituted with a hetero atom. Examples include aromatic heterocycles. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ is a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and one of the hydrogen atoms in the aromatic ring is an alkylene group. Examples thereof include a group substituted with (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group and a 2-naphthylethyl group). The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

Examples of the cyclic aliphatic hydrocarbon group in R ¹⁰¹ include an aliphatic hydrocarbon group containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an alicyclic hydrocarbon ring) and an alicyclic hydrocarbon group are linear or branched. Examples thereof include a group bonded to the end of a chain-shaped aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like.
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 a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among them, the polycycloalkane is a polycycloalkane having a polycyclic skeleton of a crosslinked ring system such as adamantan, norbornane, isobornane, tricyclodecane, and tetracyclododecan; a fused ring system such as a cyclic group having a steroid skeleton. Polycycloalkanes having a polycyclic skeleton of are more preferred.

Among them, as the cyclic aliphatic hydrocarbon group in R ¹⁰¹ , a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from a polycycloalkane is more preferable. Preferably, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and carbon. The number 1 to 4 is more preferable, and the number of carbon atoms 1 to 3 is particularly preferable.
As the 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- ], tetramethylene group [-(CH ₂ ) _4- ], pentamethylene group [-(CH ₂ ) _5- ] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -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 -etc. Alkyl methylene groups;- CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -C (CH ₂ ) CH ₃ ) ₂ -CH ₂ -etc. Alkylethylene groups; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ -etc. Alkyltrimethylene groups; -CH (CH ₃ ) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH _2- , −CH ₂ CH (CH ₃ ) CH ₂ CH _2- and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Further, the cyclic hydrocarbon group in R ¹⁰¹ may contain a hetero atom such as a heterocycle. Specifically, the lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively, and the general formulas (a5-r-1) to (a5-r-). Examples thereof include a _—SO2 -containing cyclic group represented by 4) and a heterocyclic group represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively.

Examples of the substituent in the cyclic group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, a carbonyl group, a nitro group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are most preferable.
As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group are more preferable, and methoxy. Groups and ethoxy groups are most preferred.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
As the alkyl halide group as a substituent, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are described above. Examples include groups substituted with halogen atoms.
The carbonyl group as a substituent is a group that substitutes the methylene group ( _-CH2- ) constituting the cyclic hydrocarbon group.

Chain-like alkyl group which may have a substituent:
The chain-like alkyl group of R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group and a tetradecyl group. Examples thereof include a group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group and a docosyl group.
The branched-chain 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, Examples thereof include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

Chain alkenyl group which may have a substituent:
The chain alkenyl group of R ¹⁰¹ may be either linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and preferably 2 to 4 carbon atoms. More preferably, 3 carbon atoms is particularly preferable. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butynyl group and the like. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, a 2-methylpropenyl group and the like.
Among the above, as the chain alkenyl group, a linear alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group in R ¹⁰¹ . 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, for example, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; the above general formulas (a2-r-1) to (a2-r-7), respectively. The lactone-containing cyclic group to be used; the _—SO2 -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively, is preferable.

In 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. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms and the like.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: -O-), an ester bond (-C (= O) -O-), and an oxycarbonyl group (-OC (= O-). )-), Amid bond (-C (= O) -NH-), carbonyl group (-C (= O)-), carbonate bond (-OC (= O) -O-) and other non-hydrocarbons. Oxygen atom-containing linking group of the system; Examples thereof include a combination of the oxygen atom-containing linking group of the non-hydrocarbon system and an alkylene group. A sulfonyl group (-SO _2- ) may be further linked to this combination. Examples of the divalent linking group containing such an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7).

［式中、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 the formula, ^V'101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and ^V'102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms. ]

The divalent saturated hydrocarbon group in ^V'102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and an alkylene group having 1 to 5 carbon atoms. Is more preferable.

The alkylene group in ^V'101 and ^V'102 may be a linear alkylene group or a branched chain alkylene group, and a linear alkylene group is preferable.
Specific examples of the alkylene group in ^V'101 and ^V'102 are methylene group [-CH ₂ -];-CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, -C (CH ₃ ). _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) ₂ -etc. Alkyl methylene group; 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 ) Alkylethylene 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 ) Alkyltrimethylene groups such as CH _2- ; Tetramethylene groups [-CH ₂ CH ₂ CH ₂ CH _2- ]; -CH (CH ₃ ) CH ₂ CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ Alkyltetramethylene groups such as CH _2- ; pentamethylene groups [-CH ₂ CH ₂ CH ₂ CH ₂ CH _2- ] and the like can be mentioned.
Further, a part of the methylene group in the alkylene group in ^V'101 or ^V'102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic ring-type group is a cyclic aliphatic hydrocarbon group in R ¹⁰¹ in the above formula (b-1) (monocyclic alicyclic hydrocarbon group, polycyclic alicyclic hydrocarbon group). A divalent group obtained by removing one hydrogen atom from the group is preferable, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferable.

As Y ¹⁰¹ , a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and they are represented by the above formulas (y-al-1) to (y-al-5), respectively. Linking groups are more preferred.

In formula (b-1), V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and the fluorinated alkylene group in V ¹⁰¹ preferably have 1 to 4 carbon atoms. Examples of the fluorinated alkylene group in V ¹⁰¹ include a group in which a part or all of the hydrogen atom of the alkylene group in V ¹⁰¹ is 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 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 portion of the component (b-1) include fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutane sulfonate anion when Y ¹⁰¹ is a single bond ^; When it is a divalent linking group containing an oxygen atom, an anion represented by any of the following 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”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、ｔ”は１～３の整数であり、ｎ”は０または１である。］

[In the formula, R " ¹⁰¹ is an aliphatic ring-type group which may have a substituent, a group represented by the above formulas (r-hr-1) to (r-hr-6), or a substituent, respectively. A chain alkyl group which may have a group; R " ¹⁰² is an aliphatic cyclic group which may have a substituent, said general formulas (a2-r-1) to (a2-). The lactone-containing cyclic group represented by r-7) or the _-SO2 -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 alkenyl group which may have a substituent. V "is an independently integer of 0 to 3, q" is independently an integer of 1 to 20, t "is an integer of 1 to 3, and 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 in R ¹⁰¹ . Examples of the substituent include the same substituents which may replace the cyclic aliphatic hydrocarbon group in R ¹⁰¹ .

The aromatic cyclic group which may have a substituent in R " ¹⁰³ is preferably a group exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group in R ^101. The substituent is preferably a group. , The same as the substituent which may replace the aromatic hydrocarbon group in R ¹⁰¹ .

The chain-like alkyl group which may have a substituent in R " ¹⁰¹ is preferably a group exemplified as the chain-like alkyl group in R ^101. It has a substituent in R " ¹⁰³ . The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ .

-In the anion part formula (b-2) of the component (b-2), R ¹⁰⁴ and R ¹⁰⁵ may independently have a substituent, even if they have a cyclic group or a substituent. Examples thereof include a good chain-like alkyl group or a chain-like alkenyl group which may have a substituent, and the same as R ¹⁰¹ in the formula (b-1), respectively. However, R ¹⁰⁴ and R ¹⁰⁵ may be coupled to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain-like alkyl group which may have a substituent, and are a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. Is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. The carbon number of the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range. Further, in the chain-like alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ , the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the stronger the acid strength, and the higher the energy resistance to high-energy light and electron beams of 200 nm or less. It is preferable because it improves transparency. The ratio of fluorine atoms in the chain-shaped alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. It is a perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² are independently single bonds or oxygen atoms, respectively.

-In the anion part formula (b-3) of the component (b-3), R ¹⁰⁶ to R ¹⁰⁸ may independently have a substituent, even if they have a cyclic group or a substituent. Examples thereof include a good chain-like alkyl group or a chain-like alkenyl group which may have a substituent, respectively, similar to R ¹⁰¹ in the formula (b-1).
L ¹⁰³ to L ¹⁰⁵ are each independently single-bonded, -CO- or -SO _2- .

{Cation part}
In the formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, M'm ⁺ is an m-valent onium cation, and sulfonium cations and iodonium cations are preferable. Can be mentioned. For example, it is particularly preferable that M'm ⁺ is an organic cation represented by the following general formulas (ca-1) to (ca-5), respectively.

［式中、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ルキル基、置換基を有していてもよいアルケニル基、又は置換基を有していてもよい－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 formula, R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² each represent an aryl group, an alkyl group or an alkenyl group which may independently have a substituent, and represent R ²⁰¹ to R ²⁰³ and R ²⁰⁶ to R 206. R ²⁰⁷ and R ²¹¹ to R ²¹² may be bonded to each other to form a ring together 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, and R ²¹⁰ is an alkyl group which may have a substituent and an alkenyl group which may have a substituent. , Or a _—SO2 -containing cyclic group which may have a substituent, L ²⁰¹ represents —C (= O) − or —C (= O) —O—, and Y ²⁰¹ is, respectively. Independently, it represents an arylene group, an alkylene group or an alkenylene group, x is 1 or 2, and W ²⁰¹ represents a (x + 1) -valent linking group. ]

Examples of the aryl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² preferably has 2 to 10 carbon atoms.
Substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have include, for example, an alkyl group, a halogen atom, an alkyl halide group, a carbonyl group, a cyano group, an amino group, an aryl group, and the following. Groups represented by the formulas (ca-r-1) to (ca-r-8) can be mentioned.

［式中、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、置換基を有していてもよい鎖状のアルキル基、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る。］

[In the formula, each ^R'201 independently has a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group which may be used. ]

The cyclic group which may have a substituent of ^R'201 , the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent may be described above. In addition to the same as R ¹⁰¹ in the formula (b-1) of the above, examples of the cyclic group which may have a substituent or the chain alkyl group which may have a substituent are described above. The same as the acid dissociable group represented by the formula (a1-r-2) of (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 bonded to each other to form a ring together with the sulfur atom in the formula, heteroatomic atoms such as sulfur atom, oxygen atom, and nitrogen atom, and heteroatomic atoms such as sulfur atom, oxygen atom, and nitrogen atom are formed. Carbonyl group, -SO-, -SO _2- , -SO _3- , -COO-, -CONH- or _-N (RN)-(the _RN is an alkyl group having 1 to 5 carbon atoms), etc. It may be bonded via the functional group of. As the ring to be formed, one ring containing a sulfur atom in its ring skeleton, including the sulfur atom, is preferably a 3- to 10-membered ring, and particularly preferably a 5- to 7-membered ring. preferable. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxatiin ring, tetrahydro. Examples thereof include a thiophenium ring and a tetrahydrothiopyranium ring.

R ²⁰⁸ to R ²⁰⁹ independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable, and when they are alkyl groups, they are bonded to each other. A ring may be formed.

R ²¹⁰ is an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a _—SO2 -containing cyclic group which may have a substituent.
The alkyl group in R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²¹⁰ preferably has 2 to 10 carbon atoms.
In R ²¹⁰ , the —SO _{2 -} containing cyclic group which may have a substituent is represented by the above general formulas (a5-r-1) to (a5-r-4), respectively. -Similar to the contained cyclic group can be mentioned, and among these, " _-SO2 -containing polycyclic group" is preferable, and the group represented by the general formula (a5-r-1) is more preferable.

In the above formulas (ca-4) and (ca-5), Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkenylene group, respectively.
Examples of the arylene group in Y ²⁰¹ include a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in R ¹⁰¹ in the above formula (b-1).
Examples of the alkylene group and the alkaneylene group in Y ²⁰¹ include a chain alkyl group in R ¹⁰¹ in the above formula (b-1) and a group obtained by removing one hydrogen atom from the group exemplified as the chain alkenyl group. ..

In the above formula (ca-4) and formula (ca-5), x is 1 or 2.
W ²⁰¹ is a (x + 1) valence, i.e., a divalent or trivalent linking group.
As the divalent linking group in W ²⁰¹ , a divalent hydrocarbon group which may have a substituent is preferable, and it has a substituent similar to Ya ²¹ in the above general formula (a2-1). Examples thereof include divalent hydrocarbon groups which may be used. The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, and is preferably cyclic. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
Examples of the trivalent linking group in W ²⁰¹ 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. Can be mentioned. As the trivalent linking group in W ²⁰¹ , a group in which two carbonyl groups are bonded to an arylene group is preferable.

Specific examples of suitable cations represented by the above formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-129).

［式中、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 formula, g1, g2, and g3 indicate the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

［式中、Ｒ”^２０１は水素原子又は置換基であって、該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 the formula, R " ²⁰¹ is a hydrogen atom or a substituent, and the substituents are the same as those listed as the substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have. Is.]

Specific examples of the suitable cation represented by the formula (ca-2) include diphenyliodonium cation, bis (4-tert-butylphenyl) iodonium cation and the like.

Specific examples of suitable cations represented by the above formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-5).

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

Further, as the cation represented by the above formula (ca-5), the cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferable.

Among the above, the cation portion [( ^{M'm +} ) _{1 / m} ] is preferably a cation represented by the general formula (ca-1), and more preferably a monophenyl type cation.
Further, as a preferable cation portion [( ^{M'm +} ) _{1 / m} ], a monophenyl type cation represented by the following general formula (ca-1-0) can be mentioned.

［式中、Ｒ^ｂ１は、置換基を有してもよいアリール基である。Ｒ^ｂ２及びＲ^ｂ３は、それぞれ独立に、脂肪族炭化水素基である。Ｒ^ｂ２とＲ^ｂ３とは相互に結合して環構造を形成していてもよい。Ｌ^ｂ１、Ｌ^ｂ２及びＬ^ｂ３は、それぞれ独立に、２価の連結基又は単結合である。］

[In the formula, R ^b1 is an aryl group which may have a substituent. R ^b2 and R ^b3 are independently aliphatic hydrocarbon groups. R ^b2 and R ^b3 may be coupled to each other to form a ring structure. L ^b1 , L ^b2 and L ^b3 are independently divalent linking groups or single bonds, respectively. ]

In the above formula (ca-1-0), R ^b1 is an aryl group which may have a substituent, and is the same as the aryl group which may have a substituent in R ²⁰¹ to R ²⁰³ . That is, examples of the aryl group in R ^b1 include an aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable. Examples of the substituent that R ^b1 may have include an alkyl group, a halogen atom, an alkyl halide group, a carbonyl group, a cyano group, an amino group and an aryl group, and the above formulas (ca-r-1) to ( The groups represented by ca-r-8) can be mentioned.

In the above formula (ca-1-0), R ^b2 and R ^b3 are independently aliphatic hydrocarbon groups. The aliphatic hydrocarbon group in R ^b2 and R ^b3 may be chain-like or cyclic, and examples thereof include a chain-like or cyclic alkyl group and an alkenyl group.
As the chain or cyclic alkyl group here, those having 1 to 30 carbon atoms are preferable.
The alkenyl group here preferably has 2 to 10 carbon atoms.

R ^b2 and R ^b3 may be coupled to each other to form a ring structure. When they are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatomic atoms such as sulfur atom, oxygen atom and nitrogen atom, carbonyl group, -SO-, -SO _2- , -SO _3- , -COO It may be bonded via a functional group such as-, -CONH- or _-N (RN)-(the _RN is an alkyl group having 1 to 5 carbon atoms). As the ring to be formed, one ring containing a sulfur atom in its ring skeleton, including the sulfur atom, is preferably a 3- to 10-membered ring, and particularly preferably a 5- to 7-membered ring. preferable. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxatiin ring, tetrahydro. Examples thereof include a thiophenium ring and a tetrahydrothiopyranium ring.

In the above formula (ca-1-0), L ^b1 , L ^b2 and L ^b3 are independently divalent linking groups or single bonds, respectively.
The divalent linking groups in L ^b1 , L ^b2 and L ^b3 are independently -C (= O)-, -C (= O) -O-, -OC (= O)-, and Aliren. Examples include a group, an alkylene group, an alkenylene group and the like.

Examples of the arylene group in L ^b1 , L ^b2 and L ^b3 include a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in R ¹⁰¹ in the above formula (b-1). That is, two hydrogen atoms are removed from the aromatic ring (benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle in which some of the carbon atoms constituting these aromatic rings are replaced with heteroatoms, etc.). Benzene can be mentioned.
The alkylene group or alkenylene group in L ^b1 , L ^b2 and L ^b3 is a chain alkyl group in R ¹⁰¹ in the above formula (b-1), and a hydrogen atom is further added from the group exemplified as the chain alkenyl group. Excluded groups are mentioned. That is, a group obtained by removing one hydrogen atom from a linear alkyl group having 1 to 20 carbon atoms and a group obtained by removing one hydrogen atom from a branched alkyl group having 3 to 20 carbon atoms. Can be mentioned.

L ^b1 is preferably a single bond because the acid generation efficiency due to exposure is further enhanced.

The cation portion of the component (B) is more preferably a cation represented by the following general formula (ca-1-01) or a cation represented by the general formula (ca-1-02). Particularly preferred is a cation represented by the general formula (ca-1-01).

［式中、Ｒ^ｂ１１及びＲ^ｂ１２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である。Ｌ^ｂ１１は、－Ｃ（＝Ｏ）－または－Ｃ（＝Ｏ）－Ｏ－である。Ｒ^ｂ１２１及びＲ^ｂ１２２は、それぞれ独立に、水素原子又は炭素数１～５のアルキル基である。ｎｂ１は、１～３の整数である。ｎｂ２は、１～３の整数である。］

[In the formula, R ^b11 and R ^b12 are aryl groups which may independently have a substituent. L ^b11 is -C (= O)-or -C (= O) -O-. R ^b121 and R ^b122 are independently hydrogen atoms or alkyl groups having 1 to 5 carbon atoms. nb1 is an integer of 1 to 3. nb2 is an integer of 1 to 3. ]

In the above formula, R ^b11 and R ^b12 are the same as R ^b1 in the above formula (ca-1-0), respectively. Of these, an unsubstituted aryl group is preferable. Preferred aryl groups include phenyl groups and naphthyl groups.
Each of R ^b121 and R ^b122 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom, a methyl group or an ethyl group is preferable, and a hydrogen atom is more preferable.
nb1 is an integer of 1 to 3, preferably 1 or 2, and more preferably 2.
nb2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

As the cation represented by the general formula (ca-1-01), the cations represented by the above chemical formulas (ca-1-104) to (ca-1-129) are preferable, and among these, the cations represented by the chemical formula (ca-1-129) are preferable. A cation represented by ca-1-104) and a cation represented by the chemical formula (ca-1-105) (when R " ²⁰¹ is a hydrogen atom) are more preferable.
As the cation represented by the general formula (ca-1-02), the cation represented by the above chemical formula (ca-1-102) and the cation represented by the chemical formula (ca-1-103) are preferable.

As the component (B), the above-mentioned acid generator may be used alone or in combination of two or more.
As the component (B) in the present embodiment, a compound represented by the following general formula (b-1-0) is particularly preferable.

［式中、Ｒ^１０１、Ｙ^１０１、Ｖ^１０１及びＲ^１０２は、前記式（ｂ－１）中のＲ^１０１、Ｙ^１０１、Ｖ^１０１及びＲ^１０２とそれぞれ同様である。Ｒ^ｂ１１及びｎｂ１は、前記式（ｃａ－１－０１）中のＲ^ｂ１１及びｎｂ１とそれぞれ同様である。］

[In the formula, R ¹⁰¹ , Y ¹⁰¹ , V ¹⁰¹ and R ¹⁰² are the same as R ¹⁰¹ , Y ¹⁰¹ , V ¹⁰¹ and R ¹⁰² in the formula (b-1), respectively. R ^b11 and nb1 are the same as R ^b11 and nb1 in the above formula (ca-1-01), respectively. ]

When the resist composition contains the component (B), the content of the component (B) is preferably 0.5 to 7 parts by mass, more preferably 1 to 4 parts by mass with respect to 100 parts by mass of the component (A). 1 to 3 parts by mass is more preferable.
By setting the content of the component (B) in the above range, pattern formation is sufficiently performed. Further, when each component of the resist composition is dissolved in an organic solvent, a uniform solution can be easily obtained, and the storage stability of the resist composition is improved, which is preferable. Further, by setting the content of the component (B) to be equal to or higher than the lower limit of the above-mentioned preferable range, the light transmittance of the resist film can be easily increased and the sensitivity can be easily increased.

-About the acid diffusion control agent component (D) In the resist composition of the present embodiment, in addition to the component (A) or in addition to the components (A) and (B), the acid diffusion control agent component ( Hereinafter, it may contain "(D) component"). The component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition.
The component (D) may be a photodisintegrating base (D1) (hereinafter referred to as “component (D1)”) that is decomposed by exposure and loses acid diffusion controllability, and includes a component (D1) that does not correspond to the component (D1). It may be a nitrogen organic compound (D2) (hereinafter referred to as “(D2) component”).

-Regarding the component (D1) By using a resist composition containing the component (D1), it is possible to improve the contrast between the exposed portion and the unexposed portion of the resist film when forming a resist pattern.
The component (D1) is not particularly limited as long as it decomposes by exposure and loses acid diffusion controllability, and is a compound represented by the following general formula (d1-1) (hereinafter, “(d1-1) component”). The compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component") and the compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-d1-) component"). 3) One or more compounds selected from the group consisting of "components") are preferable.
The components (d1-1) to (d1-3) do not act as a quencher in the exposed portion of the resist film because they decompose and lose the acid diffusion controllability (basic), and act as a quencher in the unexposed portion. do.

［式中、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、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る。但し、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フッ素原子は結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。ｍは１以上の整数であって、Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[In the formula, Rd ¹ to Rd ⁴ have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. It is an alkenyl group of. However, it is assumed that the fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or divalent linking group. m is an integer of 1 or more, and M ^{m +} is an independently m-valent organic cation. ]

{(D1-1) component}
... In the anion part formula (d1-1), Rd ¹ has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. These are chain-like alkenyl groups which may be present, and examples thereof include the same groups as R ¹⁰¹ in the above formula (b-1).
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 alkyl group is preferred. Substituents that these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, and the above general formulas (a2-r-1) to (a2-r-). Examples thereof include a lactone-containing cyclic group represented by 7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, an alkylene group may be used as a substituent, and the substituent in this case is represented by the above formulas (y-al-1) to (y-al-5), respectively. Linking groups are preferred.
As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The chain-like alkyl group preferably has 1 to 10 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and the like. Linear alkyl groups such as nonyl group and decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl Examples thereof include branched alkyl groups such as a group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms. , 1 to 4 carbon atoms are more preferable. The fluorinated alkyl group may contain an atom other than the fluorine atom. Examples of the atom other than the fluorine atom include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms, and the hydrogen atom constituting the linear alkyl group is preferable. It is particularly preferable that it is a fluorinated alkyl group (linear perfluoroalkyl group) in which all are substituted with a fluorine atom.

A preferable specific example of the anion portion of the component (d1-1) is shown below.

... In the cation part equation (d1-1), M ^{m +} is an organic cation having an m valence.
As the organic cation of M ^{m +} , the same cations as those represented by the general formulas (ca-1) to (ca-5) are preferably mentioned, and are represented by the general formula (ca-1). Cations are more preferable, and cations represented by the above formulas (ca-1-1) to (ca-1-129) are even more preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) component}
... In the anion part formula (d1-2), Rd ² has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group which may be used, and examples thereof include the same group as R ¹⁰¹ in the above formula (b-1).
However, it is assumed that the fluorine atom is not bonded (fluorine-substituted) to the carbon atom adjacent to the S atom in Rd ² . As a result, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the quenching ability as the component (D) is improved.
Rd ² is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantan, norbornan, isobornan, tricyclodecane, tetracyclododecane and the like (may have a substituent); one from camphor and the like. It is more preferable that the group is a group excluding the above hydrogen atom.
The hydrocarbon group of Rd ² may have a substituent, and the substituent may be a hydrocarbon group (aromatic hydrocarbon group, aliphatic ring-type group) in Rd ¹ of the above formula (d1-1). Examples thereof include the same substituents that the chain-like alkyl group) may have.

A preferable specific example of the anion portion of the component (d1-2) is shown below.

... In the cation part formula (d1-2), M ^{m +} is an m-valent organic cation, which is the same as M ^{m +} in the above 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) component}
... In the anion part formula (d1-3), Rd ³ has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be present, and the same group as R ¹⁰¹ in the above formula (b-1) can be mentioned, and a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl can be mentioned. It is preferably a group. Of these, a fluorinated alkyl group is preferable, and the same group as the fluorinated alkyl group of Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ may have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group, and examples thereof include the same group as R ¹⁰¹ in the above formula (b-1).
Of these, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group, which may have a substituent, are preferable.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or an isobutyl group. , Tert-Butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atom 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 specifically, the alkoxy group having 1 to 5 carbon atoms is a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, or n-. Examples thereof include a butoxy group and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferable.

Examples of the alkenyl group in Rd ⁴ include the same group as R ¹⁰¹ in the above formula (b-1), and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group and a 2-methylpropenyl group are preferable. These groups may further have an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms as a substituent.

The cyclic group in Rd ⁴ is the same as that of R ¹⁰¹ in the above formula (b-1), and is derived from cycloalkanes such as cyclopentane, cyclohexane, adamantan, norbornan, isobornan, tricyclodecane, and tetracyclododecane. An alicyclic group excluding one or more hydrogen atoms, or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, so that the lithography characteristics are improved. Further, when Rd ⁴ is an aromatic group, the resist composition has excellent light absorption efficiency, and the sensitivity and lithography characteristics are good.

In formula (d1-3), Yd ¹ is a single bond or divalent linking group.
The divalent linking group in Yd ¹ is not particularly limited, but includes a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent and a hetero atom 2 Examples include the linking group of valuations. Each of these includes a divalent hydrocarbon group and a hetero atom which may have a substituent, which are mentioned in the description of the divalent linking group in Ya ²¹ in the above formula (a2-1). The same as the divalent linking group can be mentioned.
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

A preferable specific example of the anion portion of the component (d1-3) is shown below.

... In the cation part formula (d1-3), M ^{m +} is an m-valent organic cation, which is the same as M ^{m +} in the above 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), only one of the above components (d1-1) to (d1-3) may be used, or two or more of them may be used in combination.
When the resist composition contains the component (D1), the content of the component (D1) is preferably 0.5 to 10 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A). It is more preferably 8 parts by mass, and even more preferably 1 to 8 parts by mass.
When the content of the component (D1) is at least a preferable lower limit value, particularly good lithography characteristics and a resist pattern shape can be easily obtained. On the other hand, when it is not more than the upper limit, the sensitivity can be maintained well and the throughput is also excellent.

(D1) Ingredient manufacturing method:
The method for producing the component (d1-1) and the component (d1-2) is not particularly limited, and the component (d1-1) and the component (d1-2) can be produced by a known method.
The method for producing the component (d1-3) is not particularly limited, and is produced in the same manner as that described in, for example, US2012-0149916.

-Regarding the component (D2) As the acid diffusion control agent component, a nitrogen-containing organic compound component (hereinafter referred to as "(D2) component") that does not correspond to the above component (D1) may be contained.
The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines are preferable, and among them, secondary aliphatic amines and tertiary aliphatic amines are more 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 include an amine (alkylamine or alkylalcoholamine) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms, or a cyclic amine.
Specific examples of alkylamines and alkylalcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di. Dialkylamines such as -n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine and other trialkylamines; diethanolamine, triethanolamine, diisopropanolamine, tri Alkyl alcohol amines such as isopropanolamine, di-n-octanolamine and tri-n-octanolamine can be mentioned. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of the cyclic amine include a heterocyclic compound containing a nitrogen atom as a heteroatom. The heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine) or a polycyclic compound (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine, piperazine and the like.
The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specifically, 1,5-diazabicyclo [4.3.0] -5-nonen and 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane and the like can be mentioned.

Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, and tris {2. -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy) Ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like can be mentioned, with triethanolamine triacetate being preferred.

Further, as the component (D2), an aromatic amine may be used.
Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or a derivative thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine and the like.

The component (D2) may be used alone or in combination of two or more.
When the resist composition contains the component (D2), the component (D2) is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). Within the above range, the shape of the resist pattern, stability over time, and the like are improved.

-For at least one compound (E) selected from the group consisting of an organic carboxylic acid and a phosphorus oxo acid and a derivative thereof, the resist composition of the present embodiment includes prevention of sensitivity deterioration, a resist pattern shape, and drawing. At least one compound (E) selected from the group consisting of an organic carboxylic acid, a phosphorus oxo acid and a derivative thereof, as an arbitrary component, for the purpose of improving the stability over time, etc. ") Can be contained.
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 suitable.
Examples of the oxo acid of phosphorus include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the derivative of phosphorus oxo acid include an ester in which the hydrogen atom of the oxo acid is replaced with a hydrocarbon group, and examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. Examples include 15 aryl groups.
Examples of the phosphoric acid derivative include phosphoric acid esters such as phosphoric acid di-n-butyl ester and phosphoric acid diphenyl ester.
Examples of the phosphonic acid derivative include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the derivative of phosphinic acid include phosphinic acid ester and phenylphosphinic acid.
As the component (E), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (E), the component (E) is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A).

-Regarding the fluorine additive component (F) The resist composition of the present embodiment may contain a fluorine additive component (hereinafter referred to as "(F) component") in order to impart water repellency to the resist film. ..
Examples of the component (F) are described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226. Fluorine-containing polymer compounds can be used.
More specifically, as the component (F), a polymer having a structural unit (f1) represented by the following formula (f1-1) can be mentioned. The polymer is a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); the structural unit (a1) containing an acid-degradable group whose polarity is increased by the action of an acid. ) And the constituent unit (f1); a copolymer of the constituent unit (f1), a constituent unit derived from acrylic acid or methacrylic acid, and the constituent unit (a1) is preferable. Here, as the preferred structural unit (a1) copolymerized with the structural unit (f1), for example, 1-methyl, a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate. -1-Constituent units derived from adamantyl (meth) acrylate.

［式中、Ｒは前記と同様であり、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 the formula, R is the same as described above, and Rf ¹⁰² and Rf ¹⁰³ independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, respectively. Rf ¹⁰² and Rf ¹⁰³ may be the same or different. nf ¹ is an integer of 1 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom. ]

In the formula (f1-1), R bonded to the carbon atom at the α-position is the same as described above. As R, a hydrogen atom or a methyl group is preferable.
In the formula (f1-1), examples of the halogen atom of Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include the same as the above-mentioned alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferable. Examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Be done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, 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 the 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 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 has preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. , 1 to 10 carbon atoms are particularly preferable.
Further, in the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more is fluorinated, and 60% or more is fluorinated. It is particularly preferable that it is fluorinated because the hydrophobicity of the resist film during immersion exposure is increased.
Among them, as Rf ¹⁰¹ , a fluorinated hydrocarbon group having 1 to 6 carbon atoms is more preferable, and a trifluoromethyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , and -CH (CF ₃ ) are more preferable. ) ₂ , -CH ₂ -CH ₂ -CF ₃ , -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are particularly preferable.

The weight average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the component (F) is preferably 1000 to 50,000, more preferably 5000 to 40,000, and most preferably 10,000 to 30,000. When it is not more than the upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is more than the lower limit of this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good.
The dispersity (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.
When the resist composition contains the component (F), the component (F) is usually used in a ratio of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

-Regarding the organic solvent component (S) The resist composition of the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter, may be referred to as "(S) component").
The component (S) may be any component as long as it can dissolve each component to be used to form a uniform solution, and any conventionally known solvent for the chemically amplified resist composition may be appropriately used. It can be selected and used.
For example, as the component (S), lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, Polyhydric alcohols such as dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, the polyhydric alcohols or the compounds having the ester bond. Derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether and compounds having an ether bond such as monophenyl ether [among these, propylene glycol monomethyl ether acetate ( PGMEA), propylene glycol monomethyl ether (PGME)]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, Esters such as methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene , Aromatic organic solvents such as simene and mesityrene, dimethylsulfoxide (DMSO) and the like can be mentioned.
The component (S) may be used alone or as a mixed solvent of two or more kinds.
Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.

Further, a mixed solvent in which PGMEA and a polar solvent are mixed is also preferable. The compounding ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, but is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferably within the range.
More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. .. When PGME is blended as the polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, and even more preferably 3: 7 to 7 :. It is 3. Further, a mixed solvent of PGMEA, PGME and cyclohexanone is also preferable.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is 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) used is not particularly limited, and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the component (S) is used so that the solid content concentration of the resist composition is in the range of 20 to 55% by mass, preferably 30 to 45% by mass.

In the resist composition of the present embodiment, an additive which is more miscible as desired, for example, an additional resin for improving the performance of the resist film, a surfactant (for example, a fluorosurfactant), and a solution are dissolved. Inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes and the like can be appropriately added and contained.

The resist pattern forming method according to the present embodiment described above is a useful method for forming a high-thickness resist film having a film thickness of 7 μm or more, and is carried out using a specific resist composition. By using a specific resist composition, that is, a resist composition containing a resin component (A1) having a structural unit (a10), a structural unit (a4), and a structural unit (a1), a high-thickness resist film is used. Light transmission is enhanced. As a result, even when a high-thickness resist film having a film thickness of 7 μm or more is formed, high sensitivity and resolution are improved, and a resist pattern having a good shape can be formed. ..

In addition, according to such a resist pattern forming method, the solubility in a developing solution is improved by using the above-mentioned specific resist composition. As a result, the occurrence of defects can be suppressed, and the stability of the pattern dimensions can be improved. Further, according to such a resist pattern forming method, sufficient etching resistance is maintained.

Such a resist pattern forming method is useful for manufacturing a three-dimensional structure device, and is a method suitable for processing a multi-stage staircase structure (superposition, etc.). By applying the resist pattern forming method of the present invention, stacking of memory films (three-dimensionalization, manufacture of large-capacity memory) can be realized with high accuracy.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

<Preparation of resist composition>
Each component shown in Table 1 was mixed and dissolved to prepare resist compositions (1) to (6) (all having a solid content concentration of 40% by mass).

In Table 1, each abbreviation has the following meaning. The value in [] is the blending amount (part by mass).
(A) -1: A polymer compound represented by the following chemical formula (A1) -1. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.5. ¹³ The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR is the structural unit (a101) / structural unit (a41) / structural unit (a11) = 50/35. / 15.

(A) -2: A polymer compound represented by the following chemical formula (A1) -1. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.5. ¹³ The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR is the structural unit (a101) / structural unit (a41) / structural unit (a11) = 65/20. / 15.

(A) -3: Polymer compound represented by the following chemical formula (A1) -1. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.5. ¹³ The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR is the structural unit (a101) / structural unit (a41) / structural unit (a11) = 70/15. / 15.

(A) -4: Polymer compound represented by the following chemical formula (A1) -1. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.5. ¹³ The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR is the structural unit (a101) / structural unit (a41) / structural unit (a11) = 40/45. / 15.

(A) -5: A polymer compound represented by the following chemical formula (A1) -1. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.5. ¹³ The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR is the structural unit (a101) / structural unit (a41) / structural unit (a11) = 80/5. / 15.

(A) -6: A polymer compound represented by the following chemical formula (A2) -1. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.5. ¹³ The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR is the structural unit (a101) / structural unit (st1) / structural unit (a12) = 65/20. / 15.

(B) -1: An acid generator composed of a compound represented by the following chemical formula (B) -1.

(D) -1: Tri-n-pentylamine.
(E) -1: Phenylphosphoous acid (phosphorous acid).
(Add) -1: Fluorine-based surfactant, trade name "R-40" manufactured by DIC Corporation.
(S) -1: Propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 5/5 (mass ratio).

<Formation of resist pattern (I)>
(Examples 1 to 3)
Step (i):
The resist compositions (1) to (3) are each applied to an 8-inch silicon wafer using a coater, prebaked (PAB) at 130 ° C. for 90 seconds on a hot plate, and dried. A resist film having a film thickness of 15 μm was formed.
Step (ii):
Next, a KrF excimer laser (248 nm) was applied to the resist film by a KrF exposure apparatus NSR-S203B (manufactured by Nikon; NA (numerical aperture) = 0.68, σ = 0.40) with a mask pattern (6%). It was selectively irradiated via halftone).
Then, a post-exposure heating (PEB) treatment was performed at 110 ° C. for 90 seconds.
Step (iii):
Next, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developing solution, alkaline development was performed at 23 ° C. for 60 seconds. rice field.
Then, using pure water, a water rinse was performed for 30 seconds, and then shake-off drying was performed.

(Comparative Example 1)
A resist pattern was formed in the same manner as in Examples 1 to 3 except that the resist composition (6) was used.

As a result of the above-mentioned resist pattern formation (I), in each of the examples, an isolated line pattern having a space width of 5 μm (hereinafter referred to as “IS pattern”) was formed on the resist film.

[sensitivity]
The optimum exposure amount Eop (mJ / cm ² ) when the IS pattern of the target size was formed by the formation (I) of the resist pattern described above was obtained and used as the sensitivity. This is shown in Table 2 as "Eop (mJ / cm ² )".

[Shape of resist pattern]
The shape of the IS pattern formed by the above-mentioned resist pattern formation (I) was observed by a length measuring SEM (scanning electron microscope, acceleration voltage 800V, trade name: SU-8000, manufactured by Hitachi High-Technologies, Inc.) and described below. The evaluation results are shown in Table 2 as "shape" according to the evaluation criteria of. Evaluation criteria ○: Tapered shape ×: Top-round shape

From the results shown in Table 2, according to the resist pattern forming methods of Examples 1 to 3 to which the present invention is applied, high sensitivity is exhibited even when forming a resist film having a film thickness of 15 μm, and It is recognized that a pattern with a good shape can be formed.
On the other hand, in the resist pattern forming method of Comparative Example 1, which is outside the scope of the present invention, the sensitivity was low and the shape was also poor.

<Formation of resist pattern (II)>
(Examples 4 to 8)
Step (i):
The resist compositions (1) to (5) are each applied to an 8-inch silicon wafer using a coater, prebaked (PAB) at 130 ° C. for 90 seconds on a hot plate, and dried. A resist film having a film thickness of 15 μm was formed.
Step (ii):
Next, a KrF excimer laser (248 nm) was applied to the resist film by a KrF exposure apparatus NSR-S203B (manufactured by Nikon; NA (numerical aperture) = 0.68, σ = 0.40) with a mask pattern (6%). It was selectively irradiated via halftone).
Then, a post-exposure heating (PEB) treatment was performed at 110 ° C. for 90 seconds.
Step (iii):
Next, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developing solution, alkaline development was performed at 23 ° C. for 60 seconds. rice field.
Then, using pure water, a water rinse was performed for 30 seconds, and then shake-off drying was performed.

As a result of the above-mentioned resist pattern formation (II), in each of the examples, an isolated line pattern having a space width of 3 μm (hereinafter referred to as “IS pattern”) was formed on the resist film.

[Defect (number of defects)]
For the IS pattern formed by the above-mentioned resist pattern formation (II), the total number of defects in the wafer (total number of defects) was measured using a surface defect observation device (manufactured by KLA Tencol Co., Ltd., product name: KLA2371).
The number of wafers used for such measurement was two for each example, and the average value was adopted as the total number of defects (total number of defects) in the wafer. Then, according to the following evaluation criteria, the evaluation results are shown in Table 3 as "Defect".
Evaluation criteria ◎: Number of defects 200 or less ○: Number of defects more than 200 and less than 300 △: Number of defects 300 or more

[Dimensional uniformity (CDU) in the wafer surface (Shot)]
Regarding the IS pattern formed by the above-mentioned resist pattern formation (II), the IS pattern (scanning electron microscope, acceleration voltage 300V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation) was used. 7 × 15 shot) was observed from the sky, and the space width in the IS pattern (38 points in the shot) was measured. A triple value (3σ) of the standard deviation (σ) calculated from the measurement results was obtained. The smaller the value of 3σ thus obtained, the higher the dimensional (CD) uniformity of the space width formed on the resist film.
Then, according to the following evaluation criteria, the evaluation results are shown in Table 3 as "CDU".
Evaluation criteria ◎: 3σ value is 60 nm or less ○: 3σ value is more than 60 nm and less than 70 nm △: 3σ value is 70 nm or more

From the results shown in Table 3, it is confirmed that the resist pattern forming methods of Examples 4 to 8 to which the present invention is applied reduce the occurrence of defects and have high dimensional (CD) uniformity. In particular, it is recognized that these effects are further enhanced when the resist compositions (1), (2) and (3) are used (particularly, when the resist composition (2) is used).

Claims (4)

A step (i) of forming a resist film having a thickness of 7 μm or more on a support using a resist composition, a step (ii) of exposing the resist film, and developing the resist film after the exposure to form a resist pattern. A resist pattern forming method having a forming step (iii).
The resist composition generates an acid by exposure, and the solubility in the developing solution changes due to the action of the acid. The structural unit (a10) represented by the following general formula (a10-1) and the acid. It contains a resin component (A1) having a structural unit (a4) containing a non-dissociable aliphatic cyclic group and a structural unit (a1) containing an acid-degradable group whose polarity is increased by the action of an acid .
A method for forming a resist pattern, wherein the acid-degradable group in the structural unit (a1) contains an acid-dissociative group represented by the following general formula (a1-r2-11) .

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or divalent linking group. Wa ^x1 is an aromatic hydrocarbon group having a (n _ax1 + 1) valence. n _ax1 is an integer of 1 to 3. ]

[In the formula, Ra'10 is a hydrocarbon group having 1 to 10 carbon atoms ^. Ra " ¹¹ is a group that forms a monocyclic aliphatic cyclic group together with the carbon atom to which Ra '10 is bonded. * Is a bond. ^] The resist pattern forming method according to claim 1 , wherein the content ratio of the structural unit (a10) is 45 to 75 mol% with respect to all the structural units (100 mol%) constituting the resin component (A1). The resist pattern formation according to claim 1 or 2 , wherein the content ratio of the structural unit (a1) is 5 to 20 mol% with respect to all the structural units (100 mol%) constituting the resin component (A1). Method. The resist pattern forming method according to any one of claims 1 to 3 , wherein in the step (ii), the resist film is irradiated with KrF excimer laser light.