JP2013225025A - Pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern forming method.SOLUTION: The pattern forming method includes steps of: forming a resist film by applying to a support body a negative resist composition comprising a base component (A) that causes decrease in the solubility with an organic solvent by an action of an acid, and an acid generator component (B) that generates an acid by exposure; exposing the resist film; forming a resist pattern by developing the resist film by use of a developing solution containing the organic solvent; forming a layer containing a block copolymer having a plurality of types of blocks bonded to one another on the support body where the resist pattern is formed, and then inducing phase separation in the layer containing the block copolymer; and selectively removing a phase comprising at least one type of block in the plurality of types of blocks that constitute the block copolymer from the layer containing the block copolymer. The base component (A) does not include an ether-containing cyclic group.

Description

  The present invention relates to a method for forming a pattern using a phase separation structure of a block copolymer.

  In recent years, with the further miniaturization of large-scale integrated circuits (LSIs), a technique for processing more delicate structures is required. In response to such a demand, attempts have been made to form a finer pattern using a phase separation structure formed by self-assembly of block copolymers in which incompatible blocks are bonded to each other. (For example, refer to Patent Document 1).

  In order to use the phase separation of the block copolymer, it is essential to form the self-assembled nanostructure formed by the microphase separation only in a specific region and arrange it in a desired direction. In order to realize these position control and orientation control, methods such as grapho epitaxy for controlling the phase separation pattern by the guide pattern and chemical epitaxy for controlling the phase separation pattern by the difference in the chemical state of the substrate have been proposed. (For example, refer nonpatent literature 1).

  In order to realize the position control and the orientation control, a resist material containing a base material component such as a resin is used for forming the guide pattern. The resist material is classified into a positive type and a negative type. A resist material whose solubility in an exposed portion of a developer is increased is called a positive type, and a resist material whose solubility in an exposed portion of a developer is reduced is called a negative type. . At the time of forming a fine pattern using self-organization of a block copolymer, a negative development process has been proposed for a guide pattern. The negative development process is a process (hereinafter referred to as organic development) in which the positive chemically amplified resist composition is combined with a developer containing an organic solvent (hereinafter also referred to as “organic developer”). The process using the liquid is sometimes referred to as “solvent development process” or “solvent development negative process”. The positive chemically amplified resist composition increases the solubility in an alkaline developer by exposure, but at this time, the solubility in an organic solvent is relatively decreased. Therefore, in the solvent development negative process, the unexposed portion of the resist film is dissolved and removed by an organic developer to form a resist pattern (see, for example, Patent Document 2).

JP 2008-36491 A JP 2009-025723 A

Proceedings of SPIE, Volume 7637, 76370G-1 (2010).

  Conventionally, a resist pattern using a negative resist composition containing a crosslinking agent has been used as a guide pattern using a solvent-developed negative process in which a negative chemically amplified resist composition and an organic developer are combined. Has been proposed. The resist composition in which the crosslinking agent is blended needs a heat treatment step for crosslinking. If a resist composition not having a crosslinking agent can be used, one step in pattern formation can be omitted. In addition, there are many resist compositions on the market that do not contain a crosslinking agent or the like, and there is a need to use a commercially available resist composition.

  The present invention has been made in view of the above circumstances, and a solvent-developed negative resist composition having no crosslinking agent is used as a guide pattern when forming a fine pattern utilizing self-organization of a block copolymer. It is an object of the present invention to provide a pattern forming method.

The pattern forming method of the present invention is a solvent-developed negative resist containing a base component (A) whose solubility in an organic solvent is reduced by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. A step of forming a resist film by applying the composition onto a support, a step of exposing the resist film, and developing the resist film using a developer containing the organic solvent to form a resist pattern Forming a layer containing a block copolymer in which a plurality of types of blocks are bonded on a support on which the resist pattern is formed, and then phase-separating the layer containing the block copolymer; and A step of selectively removing a phase composed of at least one of a plurality of types of blocks constituting the block copolymer in the containing layer; When, a pattern forming method characterized by having a. The base component (A) does not have a 3 to 7-membered ether ring-containing cyclic group.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent that replaces the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydroxy group. An alkyl group etc. are mentioned. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
Hereinafter, an acrylate 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 acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.
“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. The derivatives include those in which the hydrogen atom at the α-position may be substituted with a substituent, the hydrogen atom of the hydroxyl group of hydroxystyrene substituted with an organic group, and the hydrogen atom at the α-position substituted with a substituent. Examples include those in which a substituent other than a hydroxyl group is bonded to a good benzene ring of hydroxystyrene. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those mentioned as the substituent at the α-position in the α-substituted acrylic ester.
The “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit configured by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including a compound in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those obtained by substituting the hydrogen atom of the carboxy group of vinyl benzoic acid with an organic group, which may be substituted with a hydrogen atom at the α-position, and the hydrogen atom at the α-position 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 (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
“Styrene” is a concept that includes styrene and those in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.
The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, when forming a fine pattern using self-organization of a block copolymer, a pattern can be formed using a solvent-developed negative resist composition having no crosslinking agent as a guide pattern. .

It is a schematic process drawing explaining the example of an embodiment of the pattern formation method of the present invention.

  The pattern forming method of the present invention will be described with reference to FIG. In the pattern forming method of the present invention, the support can be obtained by, for example, the step (1) of applying a base agent on the substrate 11 and forming the layer 12 made of the base agent. The pattern forming method of the present invention includes a step (2) of forming a resist pattern 14 on a support using a solvent development negative resist composition, and a layer 13 containing a block copolymer in which a plurality of types of blocks are bonded. A step (3) of forming a phase copolymer on the layer 13 containing the block copolymer after the resist pattern 14 is formed on the support, and a plurality of layers constituting the block copolymer among the layers 13 containing the block copolymer. And a step (4) of selectively removing the phase 13a composed of at least one of the types of polymers.

  Hereinafter, embodiments of the pattern forming method of the present invention will be specifically described with reference to the drawings. However, the present invention is not limited to this.

[Step (1)]
The substrate 11 is not particularly limited as long as it is not dissolved or mixed when a base agent or a block copolymer is applied, and a conventionally known substrate can be used as a substrate for an electronic component.
For example, a silicon substrate, a metal substrate made of metal such as gold, copper, chromium, iron, and aluminum; a metal oxide substrate formed by oxidizing the metal; a glass substrate, a polymer film (polyethylene, polyethylene terephthalate, polyimide, benzocyclobutene) Etc.). Further, the size and shape of the substrate 11 are not particularly limited. The substrate does not necessarily have a smooth surface, and substrates of various materials and shapes can be selected as appropriate. For example, a substrate having a curved surface, a flat plate having an uneven surface, and a substrate having various shapes such as a flake shape can be used.

The substrate 11 may be a substrate in which an inorganic and / or organic film is provided on the substrate as described above, and is preferably a substrate in which an organic film is provided. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).
The inorganic film can be formed, for example, by coating an inorganic antireflection film composition such as a silicon-based material on a substrate and baking.
The organic film is, for example, a material for forming an organic film in which a resin component or the like constituting the film is dissolved in an organic solvent is applied onto a substrate with a spinner or the like, preferably 200 to 300 ° C., preferably 30 to 300. It can be formed by baking for 2 seconds, more preferably 60 to 180 seconds. The organic film forming material used at this time does not necessarily require sensitivity to light or an electron beam, such as a resist film, and may or may not have such sensitivity. Good. Specifically, resists and resins generally used in the manufacture of semiconductor elements and liquid crystal display elements can be used.
In addition, the organic film forming material can be etched, particularly dry-etched so that the organic film can be formed by etching the organic film using a block copolymer pattern to transfer the pattern to the organic film. A material capable of forming an organic film is preferable. Among these, a material capable of forming an organic film capable of etching such as oxygen plasma etching is preferable. Such an organic film forming material may be a material conventionally used for forming an organic film such as an organic BARC. Examples include the ARC series manufactured by Brewer Science, the AR series manufactured by Rohm and Haas, and the SWK series manufactured by Tokyo Ohka Kogyo.
Here, since the base agent has a substrate interaction group, the substrate 11 and the layer 12 made of the base agent can be satisfactorily used even when the substrate 1 provided with the organic film as described above is used. The layers 12 made of the base agent can be made strong and have excellent adhesion.

Further, the surface of the substrate 11 may be cleaned in advance. By cleaning the substrate surface, the subsequent neutralization reaction treatment may be performed satisfactorily.
As the cleaning treatment, a conventionally known method can be used, and examples thereof include oxygen plasma treatment, ozone oxidation treatment, acid-alkali treatment, and chemical modification treatment.

The method for applying the base agent on the substrate 11 to form the layer 12 made of the base agent is not particularly limited, and can be formed by a conventionally known method.
For example, the layer 12 made of the base agent can be formed by applying the base agent onto the substrate 11 by a conventionally known method such as spin coating or using a spinner to form a coating film and drying it. Details of the base agent will be described later.
As a method for drying the coating film, it is sufficient if the organic solvent contained in the base material can be volatilized, and examples thereof include a baking method.
The baking temperature is preferably 80 to 300 ° C, more preferably 100 to 270 ° C, and further preferably 120 to 250 ° C. The baking time is preferably 30 to 500 seconds, and more preferably 60 to 240 seconds.
By providing the base material layer 12 on the surface of the substrate 11, the surface of the substrate 11 is neutralized, and among the layer 13 made of a block copolymer provided on the upper layer, only the phase made of a specific block is in contact with the substrate surface. Can be suppressed. As a result, it is possible to form a cylinder structure, a dot structure, a gyroid structure, or the like that is freely oriented with respect to the substrate surface by phase separation of the layer 13 containing the block copolymer.

(Base material)
The base agent is not particularly limited as long as it has affinity for any of a plurality of types of blocks constituting the layer 13 made of a block copolymer, but a film made of a resin composition can be used.
The resin composition used as the base agent can be appropriately selected from conventionally known resin compositions used for thin film formation, depending on the type of block constituting the block copolymer. The resin composition used as the base agent may be a thermopolymerizable resin composition or a photosensitive resin composition. Moreover, the composition which can form patterns, such as a positive resist composition and a negative resist composition, may be sufficient.
In addition, the layer 12 made of the base material may be a non-polymerizable film. For example, siloxane-based organic monomolecular films such as phenethyltrichlorosilane, octadecyltrichlorosilane, and hexamethyldisilazane can also be suitably used as the neutralized film.

As such a base agent, for example, a composition containing a resin containing all of the constituent units of each block constituting the block copolymer and a constituent unit having high affinity with each block constituting the block copolymer are included. Examples thereof include a composition containing a resin.
For example, when a PS-PMMA block copolymer is used, a resin containing both a structural unit derived from styrene and a structural unit derived from methyl methacrylate as a resin contained in the base agent; PS such as an aromatic ring It is preferable to use a resin or the like that includes both a portion having high affinity and a portion having high affinity to PMMA such as a functional group having high polarity.

Examples of the resin including both a structural unit derived from styrene and a structural unit derived from methyl methacrylate include a random copolymer obtained by random polymerization of styrene and methyl methacrylate.
As a resin including both a part having high affinity with PS and a part having high affinity with PMMA, for example, as a monomer, it is obtained by polymerizing at least a monomer having an aromatic ring and a monomer having a polar substituent. Resin.
As a monomer having an aromatic ring, one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And monomers having a heteroaryl group in which some of the carbon atoms constituting the ring of these groups are substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom.
In addition, examples of the monomer having a highly polar substituent include hydroxyalkyl in which a part of hydrogen atoms of a trimethoxysilyl group, a trichlorosilyl group, a carboxy group, a hydroxyl group, a cyano group, an amino group, and an alkyl group are substituted with a fluorine atom. And monomers having a group or the like.
In addition, as a compound containing both a site having high affinity with PS and a site having high affinity with PMMA, a compound containing both an aryl group such as phenethyltrichlorosilane and a highly polar substituent, an alkylsilane compound, etc. Examples include compounds containing both an alkyl group and a highly polar substituent.

[Step (2)]
<Resist pattern formation (graphoepitaxy)>
In the present invention, as shown in FIG. 1, a base material is applied on a substrate 11 and a layer 12 made of the base material is formed (neutralization treatment), and then a layer made of the base material. A resist pattern 14 is formed on the surface of 12 (neutralized film). Thereby, after the layer 13 containing the block copolymer is formed, it is possible to control the arrangement structure of the phase separation structure according to the shape and surface characteristics of the resist pattern 14. Such a resist pattern 14 functions as a guide pattern.

Specifically, first, a solvent development negative resist composition described later is applied onto a support with a spinner or the like, and baking (post-apply bake (PAB)) treatment is performed at a temperature of 80 to 150 ° C., for example, at 40 to 40 ° C. A resist film is formed by applying for 120 seconds, preferably 60 to 90 seconds.
Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, or a mask pattern. After performing selective exposure by drawing or the like by direct irradiation with an electron beam without passing through, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 Apply for ~ 90 seconds.
Next, the resist film is developed using a developer containing an organic solvent.
A rinse treatment is preferably performed after the development treatment. The rinsing process is preferably performed using a rinsing liquid containing an organic solvent.
Drying is performed after development or rinsing. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern can be obtained.

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

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be 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. It is an 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.
As a solvent having a refractive index larger than that of air and smaller than that of the resist film, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility and the like.

  The organic solvent used in the developer in the solvent development process is not particularly limited as long as it can dissolve the base material component (A) (base material component (A) before exposure), and can be appropriately selected from known organic solvents. . Specific examples include ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, nitrile solvents, and other polar solvents, hydrocarbon solvents, and the like. A solvent or a nitrile solvent is preferred.

  The ketone solvent is an organic solvent containing C—C (═O) —C in the structure. The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. The amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure. Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification. Further, the hydrocarbon solvent is a hydrocarbon solvent made of hydrocarbon and having no substituent (a group or atom other than a hydrogen atom and a hydrocarbon group).

  Specific examples of each solvent include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, Methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methylamylketone (2- Heptanone) and the like.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, 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 Recall monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Nethyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyruvin Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate Examples include ethyl acid, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.
As the ester solvent, a solvent represented by the general formula (1) described later or a solvent represented by the general formula (2) described later is preferably used, and a solvent represented by the general formula (1) is used. More preferably, alkyl acetate is more preferably used, and butyl acetate is most preferably used.

  Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.

  A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.

  Development processing using an organic developer can be carried out by a known development method, for example, a method in which a support is immersed in the developer for a certain period of time (dip method), or a surface tension of the developer on the surface of the support. A method that swells and rests for a certain period of time (paddle method), a method of spraying developer on the surface of the support (spray method), and a developer coating nozzle that scans at a constant speed on a support that rotates at a constant speed. For example, there is a method of continuously applying the developer (dynamic dispensing method).

After the developing treatment, before the drying, a rinsing treatment can be performed using a rinsing liquid containing an organic solvent. By rinsing, a good pattern can be formed.
As the organic solvent used in the rinsing liquid, for example, organic solvents that are difficult to dissolve the resist pattern among the organic solvents mentioned as the organic solvent used in the organic developer can be used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. 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, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. Examples of the surfactant include those described above, and nonionic surfactants are preferable, and fluorine-based surfactants or silicon-based surfactants are 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 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.
The rinsing treatment (washing treatment) using the rinsing liquid can be carried out by a known rinsing method. For example, the rinsing liquid is continuously applied onto a support rotating at a constant speed (rotary coating method). A method of immersing the support in a rinsing solution for a certain time (dip method), a method of spraying a rinsing solution on the surface of the support (spray method), and the like.

In this invention, after forming a resist pattern using a solvent-development negative resist composition, it is preferable to expose at least the resist residual part and to perform PEB. Here, the “resist remaining portion” refers to a resist film remaining on the substrate after development and resist pattern formation, for example, a line portion in a line and space pattern. By exposing the resist residue, the negative resist composition of the resist residue is completely deprotected, and the solubility in an organic solvent for dissolving the block copolymer, which will be described later, is further reduced. As a result, damage to the resist residue due to the organic solvent, which becomes a problem when the block copolymer is applied to the resist pattern, can be suppressed.
The exposure is the same as described above, but it is sufficient that it is performed at least on the remaining resist portion, may be performed only on the remaining resist portion using a mask, or the entire surface may be exposed.

  The height of the resist pattern from the substrate surface (or neutralized film surface) is preferably equal to or greater than the thickness of the layer 13 containing a block copolymer formed on the substrate surface. The height of the resist pattern from the substrate surface (or the neutralized film surface) is preferably adjusted as appropriate according to the thickness of the resist film formed by applying a solvent-developable negative resist composition for forming the resist pattern. .

  The solvent-developed negative resist composition for forming a resist pattern is compatible with any of the polymers constituting the block copolymer from among the solvent-developed negative resist compositions used for the formation of resist patterns and modifications thereof. Can be selected and used as appropriate. Examples of the resist composition include a solvent-developed negative resist composition that generates an acid upon exposure and has a reduced solubility in a developer due to the action of the acid. Details of the solvent developing negative resist composition will be described later.

  In addition, after a layer containing a block copolymer is formed on the substrate surface on which the resist pattern is formed, heat treatment is performed to cause phase separation. In the present invention, the layer 13 containing a block copolymer can be subjected to a phase separation treatment at a relatively low temperature by containing a compound described later, so that a solvent-developed negative resist composition having no crosslinking agent is used as a resist pattern. Can be used.

[Process (3)]
First, the layer 13 containing a block copolymer is formed on the substrate surface. Specifically, a block copolymer dissolved in an applicable organic solvent is applied to the surface of the substrate 11 on which the layer 12 and the layer 14 made of a base agent are formed using a spinner or the like.
The organic solvent for dissolving the block copolymer will be described later.

The thickness of the layer 13 containing the block copolymer formed on the substrate surface depends on the molecular weight (polymer period) of the block copolymer, and is generally applied in the range of 0.5 to 4.0 times the polymer period.
In the present invention, the thickness of the layer 13 containing the block copolymer may be sufficient to cause phase separation, and the lower limit of the thickness is not particularly limited, but the strength of the nanostructure, the nanostructure Considering the uniformity of the substrate on which the body is formed, it is preferably 3 nm or more, more preferably 5 nm or more.

The phase separation of the layer 13 containing the block copolymer is performed after the formation of the layer 13 containing the block copolymer, thereby forming a phase separation structure in which at least a part of the substrate surface is exposed by selective removal of the block copolymer in a subsequent process. Let The temperature of the heat treatment is preferably higher than the glass transition temperature of the layer 13 containing the block copolymer to be used and lower than the thermal decomposition temperature. For example, when the block copolymer is PS-PMMA (Mw: 18k-18k), heat treatment is preferably performed at 160 to 270 ° C. for 30 to 3600 seconds. In the present invention, the layer containing the block copolymer contains a compound described later, so that the glass transition temperature is low, and the heat treatment can be performed at a relatively low temperature.
The heat treatment is preferably performed in a gas having low reactivity such as nitrogen.

[Step (4)]
In the step (4), a pattern is formed by selectively removing the phase 13a composed of at least one block of a plurality of types of blocks constituting the block copolymer from the layer 13 including the block copolymer. To do.
Specifically, the phase of the layers 13 containing the block copolymer on a substrate after the separation structure was formed, to selectively remove at least some of the blocks of the phase in consisting of block P _B (low molecular weight) . By pre selectively removing portions of the block P _B, results enhanced dissolution in a developer, tends to selectively remove than the phase 13b to phase 13a consisting of block P _B is formed of a block P _A .

Such selective removal process does not affect relative block P _A, if a process capable of decomposing and removing the block P _B, is not particularly limited, the technique used for the removal of the resin film from within, according to the type of block P _a and P _B block can be performed appropriately selected. Also, when the pre-neutralization film is formed on the substrate surface, the neutralization film is also removed as well as phase consisting block P _B. Examples of such removal treatment include oxygen plasma treatment, ozone treatment, UV irradiation treatment, thermal decomposition treatment, and chemical decomposition treatment.

  Although the substrate on which the pattern 13b is formed by phase separation of the layer 13 containing the block copolymer as described above can be used as it is, the shape of the polymer nanostructure on the substrate can be changed by further heat treatment. It can also be changed. The temperature of the heat treatment is preferably higher than the glass transition temperature of the block copolymer used and lower than the thermal decomposition temperature. The heat treatment is preferably performed in a gas having low reactivity such as nitrogen.

<Block copolymer>
A block copolymer is a polymer in which a plurality of types of blocks are bonded. There may be two types of blocks constituting the block copolymer, or three or more types. In the present invention, the plural types of blocks constituting the block copolymer are not particularly limited as long as they are combinations in which phase separation occurs, but are preferably combinations of blocks that are incompatible with each other. Moreover, it is preferable that the phase which consists of at least 1 type block in the multiple types of block which comprises a block copolymer is a combination which can be selectively removed easily rather than the phase which consists of other types of block.

  As the block copolymer, for example, a block copolymer in which a block containing a structural unit derived from styrene or a derivative thereof and a block containing a structural unit derived from a (meth) acrylate ester are combined; from styrene or a derivative thereof A block copolymer comprising a block containing a structural unit derived from a block containing a structural unit derived from siloxane or a derivative thereof; and a block containing a structural unit derived from an alkylene oxide and a (meth) acrylate And a block copolymer in which a block containing a structural unit derived from is bonded.

  Examples of the (meth) acrylic acid ester include those in which a substituent such as an alkyl group or a hydroxyalkyl group is bonded to the carbon atom of (meth) acrylic acid. Examples of the alkyl group used as a substituent include a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, ( Nonyl methacrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, anthracene (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid 3, Examples include 4-epoxycyclohexylmethane and (meth) acrylic acid propyltrimethoxysilane.

  Examples of the styrene derivative include 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-t-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-t-butoxystyrene, 4-hydroxystyrene, 4-nitrostyrene, 3-nitrostyrene, 4-chlorostyrene, 4-fluorostyrene, 4-acetoxyvinylstyrene, vinylcyclohexane, 4-vinylbenzyl chloride, 1- Examples thereof include vinyl naphthalene, 4-vinyl biphenyl, 1-vinyl-2-pyrrolidone, 9-vinyl anthracene, vinyl pyridine and the like.

Examples of the siloxane derivative include dimethylsiloxane, diethylsiloxane, diphenylsiloxane, methylphenylsiloxane, and the like.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, isopropylene oxide, and butylene oxide.

  In the present invention, it is preferable to use a block copolymer in which a block containing a structural unit derived from styrene or a derivative thereof and a block containing a structural unit derived from a (meth) acrylic ester are combined. Specifically, polystyrene-polymethyl methacrylate (PS-PMMA) block copolymer, polystyrene-polyethyl methacrylate block copolymer, polystyrene- (poly-t-butyl methacrylate) block copolymer, polystyrene-polymethacrylic acid block copolymer, polystyrene-poly. Examples thereof include a methyl acrylate block copolymer, a polystyrene-polyethyl acrylate block copolymer, a polystyrene- (poly-t-butyl acrylate) block copolymer, and a polystyrene-polyacrylic acid block copolymer. In the present invention, it is particularly preferable to use a PS-PMMA block copolymer.

The mass average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of each block constituting the block copolymer is not particularly limited as long as it is a size capable of causing phase separation. To 500,000 are preferable, 10,000 to 400,000 are more preferable, and 20,000 to 300,000 are more preferable.
Further, the dispersity (Mw / Mn) of the block copolymer is preferably 1.0 to 3.0, more preferably 1.0 to 1.5, and still more preferably 1.0 to 1.2. In addition, Mn shows a number average molecular weight.

In the following, among the blocks constituting the block copolymer, after the block P _A blocks not be selectively removed in step, the blocks are selectively removed as P _B block. For example, after phase-separating a layer containing PS-PMMA block copolymer, a phase composed of PMMA is selectively removed by performing oxygen plasma treatment, hydrogen plasma treatment, or the like on the layer. In this case, PS is a block _{P A,} PMMA is _{P B} block.

In the present invention, phase is selectively removed (i.e., P _B of blocks phase 13a) the shape and size of the component ratio or the blocks constituting the block copolymer is defined by the molecular weight of the block copolymer. For example, by a relatively small component ratio per volume of the block P _B occupied in the block copolymer, forming a cylindrical structure phase 13a consisting of block P _B into phase 13b consisting of P _A block is present in the cylindrical Can be made. On the other hand, by the component ratio per volume of the block P _B and P _A block occupied in the block copolymer to the same extent, and the phase 13a of phase 13b and P _B block consisting of block P _A stacked alternately A lamellar structure can be formed. In addition, the size of each phase can be increased by increasing the molecular weight of the block copolymer.

The layer containing the block copolymer preferably contains a component (B ″) having a vapor pressure at 20 ° C. of 0.05 hPa or less and a freezing point of 25 ° C. or less. Here, “vapor pressure at 20 ° C.” The term “pressure” refers to the pressure of the vapor phase that is in equilibrium with the liquid phase or the solid phase at 20 ° C.
By using a compound having a specific vapor pressure as the component (B ″), it is possible to reduce the glass transition temperature (Tg) of the layer composed of the block copolymer in the pattern forming method of the present invention, and at a relatively low temperature. Even when annealing is performed, a good pattern can be formed. The vapor pressure at 20 ° C. of the component (B ″) is not particularly limited as long as it is 0.05 hPa or less, but from 0 hPa Is greater than 0.04 hPa, preferably greater than 0 hPa, more preferably less than 0.03 hPa, more preferably greater than 0 hPa and less than 0.01 hPa.

  In addition, since the freezing point of the component (B ″) is 25 ° C. or less, the component (B ″) becomes a liquid compound at room temperature of at least about 25 ° C. When a layer containing a block copolymer is formed thereon, a layer containing a block copolymer having good properties can be formed. The freezing point of the component (B ″) is not particularly limited as long as it is 25 ° C. or lower, but is preferably 20 ° C. or lower, more preferably 10 ° C. or lower, and even more preferably 0 ° C. or lower. The temperature at which a liquid phase substance maintains an equilibrium state with a solid phase at a standard atmospheric pressure of 1013.25 hPa.

  Further, as the component (B ″), the static surface tension is preferably 30 mN / m or more, more preferably 30 to 65 mN / m, and further preferably 30 to 50 mN / m. When the target surface tension is 30 mN / m or more, the layer containing the block copolymer containing the component (B ″) becomes dense. In particular, in the case of forming a layer containing a block copolymer on a support having a resist pattern, the static surface tension is small, so that the layer containing the block copolymer easily enters a fine void in the resist pattern. This is preferable because a fine pattern faithful to the resist pattern can be obtained. Here, “static surface tension” refers to a static surface tension measured by a dropping method at 20 ° C.

  Specific examples of the component (B ″) as described above include alcohols such as benzyl glycol, glycerin, phenyl diglycol, and benzyl diglycol, and esters such as triacetin, and phenyl diglycol is particularly preferable.

  The mass average molecular weight (Mw) of the component (B ″) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 600 or less, more preferably 50 to 600, and more preferably 100 to 600. It is more preferably 600. By setting the molecular weight within the above range, good heat fluidity can be obtained even at a low temperature.

As the component (B ″), one type may be used alone, or two or more types may be used in combination. When a plurality of types of the component (B ″) are used in combination, alcohols and esters A combination is preferred.
The content of the component (B ″) in the pattern forming method of the present invention is not particularly limited, but the ratio of the component (B ″) to the total of the component (B ″) and the component (C ″) described later. Is preferably 0.1 to 40% by mass, more preferably 0.3 to 35% by mass, and even more preferably 0.6 to 30% by mass.
The total amount of the (B ″) component and the (C ″) component in the layer containing the block copolymer is not particularly limited, and the concentration at which the layer containing the block copolymer can be applied to a support or the like. However, the solid content concentration including the component (A) is preferably 0.1 to 30% by mass, and preferably 0.3 to 25% by mass. Is more preferable, and 0.6 to 20% by mass is further preferable.

The (C ″) component that may be included in the layer containing the block copolymer is not particularly limited as long as it is an organic solvent that does not correspond to the component (B ″), and dissolves each component to be used. Any one can be used as long as it can be made into a uniform solution, and any one or more of conventionally known solvents for dissolving a polymer compound can be appropriately selected and used.
As the component (C ″), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Any one of conventionally known solvents for chemically amplified resists can be used. Or it can select and use 2 or more types suitably.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, List aromatic organic solvents such as phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. Can do.
In addition, as the component (C), it is preferable to select an organic solvent in which the difference in SP value (ΔSP value) from the SP value of the component (B) is in the range of 0 to 5, and the ΔSP value is 0 to 0. More preferably, it is 2.5. Here, the “SP value” is a solubility parameter, and the smaller the difference (ΔSP value) in SP value between the component (B) and the component (C), the better the compatibility and the better the pattern. .
The component (C ″) may be used alone or as a mixed solvent of two or more.
Especially, 1 or more types chosen from the group which consists of 2-heptanone, PGMEA, EL, and (gamma) -butyrolactone are preferable.

  In addition to the block copolymer, the layer containing the block copolymer may further contain an additive having a miscibility, for example, an additional resin for improving the performance of the layer composed of a base agent, for improving the coating property. A surfactant, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, a sensitizer, a base proliferating agent, a basic compound, and the like can be appropriately added and contained.

Solvent development negative resist composition <component (A)>
The solvent-developed negative resist composition used in the pattern forming method of the present invention generates a base component (hereinafter referred to as component (A)) whose solubility in an organic solvent is reduced by the action of an acid and an acid upon exposure. It contains an acid generator component (hereinafter referred to as component (B)), and component (A) does not have a 3- to 7-membered ether-containing cyclic group. Since the component (A) does not have a 3- to 7-membered ether-containing cyclic group, a heating step for imparting heat resistance to the resist pattern becomes unnecessary, and heat treatment for phase separation can be performed at a low temperature. It can be used for pattern formation using a block copolymer.
Here, the “ether-containing cyclic group” means a cyclic group containing a structure (cyclic ether) in which carbon of a cyclic hydrocarbon is substituted with oxygen.

In the present invention, the “base material component” means an organic compound having a film forming ability.
As the base material component, an organic compound having a molecular weight of 500 or more is usually used. When the molecular weight is 500 or more, it has a sufficient film forming ability and can easily form a nano-level resist pattern.
“Organic compounds having a molecular weight of 500 or more” are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. In the present specification and claims, “polymer compound” refers to a polymer having a molecular weight of 1000 or more.
In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight determined by GPC (gel permeation chromatography).

(Structural unit (a1))
The component (A) preferably contains the structural unit (a1). The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
Here, “acid-dissociable group” means
(I) an acid-dissociable group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, or
(Ii) a group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after partial bond cleavage by the action of an acid Both.
The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer changes relatively, and when the developer is an organic developer, the solubility decreases.

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

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

[Wherein, Ra ′ ¹ and Ra ′ ² are hydrogen atoms or alkyl groups, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ may be bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. Good. ]

In formula (a1-r-1), Ra ′ ¹ and Ra ′ ² are exemplified as substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester described above. Examples thereof include the same as the alkyl group, preferably a methyl group or an ethyl group, and most preferably a methyl group.

The hydrocarbon group for Ra ′ ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms; a linear or branched alkyl group is preferable, specifically , Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group 2,2-dimethylpropyl group, 2,2, -dimethylbutyl group and the like can be mentioned.
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, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

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

［式中、Ｒａ’^４〜Ｒａ’^６は炭化水素基であり、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。］

[Wherein, Ra ′ ^{4 to} Ra ′ ⁶ are hydrocarbon groups, and Ra ′ ⁵ and Ra ′ ⁶ may be bonded to each other to form a ring. ]

As the hydrocarbon group for Ra ′ ^{4 to} Ra ′ ^6, the same groups as those described above for Ra ′ ³ can be mentioned. Ra ′ ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. In the case where Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, a group represented by general formula (a1-r2-1) shown below can be given.

［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を示す。］

[Wherein, Ra ′ ¹⁰ represents an alkyl group having 1 to ¹⁰ carbon atoms, and Ra ′ ¹¹ represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ra ¹⁰ is bonded. ]

  Specific examples of the formula (a1-r2-1) are given below.

  Examples of the acid dissociable group for protecting the hydroxyl group among the polar groups include, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as “tertiary alkyloxycarbonyl acid for convenience”). Sometimes referred to as a “dissociable group”).

［式中、Ｒａ’^７〜Ｒａ’^９はアルキル基を示す。］

[Wherein, Ra ′ ^{7 to} Ra ′ ⁹ represent an alkyl group. ]

In formula (a1-r-3), Ra ′ ^{7 to} Ra ′ ⁹ are preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 groups.
Moreover, it is preferable that the total carbon number of each alkyl group is 3-7, it is more preferable that it is 3-5, and it is most preferable that it is 3-4.

  The structural unit (a1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and an acid whose polarity is increased by the action of an acid. A structural unit containing a decomposable group; a structural unit in which at least a part of hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group; vinylbenzoic acid or Examples include a structural unit in which at least a part of hydrogen atoms in —C (═O) —OH of a structural unit derived from a vinylbenzoic acid derivative is protected by a substituent containing the acid-decomposable group.

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

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１は２価の炭化水素基であり、ｎ_ａ１はそれぞれ独立に０〜２であり、
Ｒａ^１は上記式（ａ１−ｒ−１）〜（ａ１−ｒ−２）で表される酸解離性基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group, n _a1 is independently 0 to 2,
Ra ¹ is an acid dissociable group represented by the above formulas (a1-r-1) to (a1-r-2). ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, or 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 part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.
The hydrocarbon group for Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specific 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.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. 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 preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic 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 those described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferred and 6-10 is most preferred. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; a part of carbon atoms constituting the aromatic hydrocarbon ring is hetero Aromatic heterocycles substituted with atoms; and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
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) ) In which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group in which one hydrogen atom is further removed from the aryl group in the group); and the like. The alkylene group (the 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.
Specific examples of the formula (a1-1) are shown below.

  The proportion of the structural unit (a1) in the component (A) is preferably from 20 to 80 mol%, more preferably from 20 to 75 mol%, more preferably from 25 to 70 mol%, based on all structural units constituting the component (A). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when a solvent-developed negative resist composition is used, and the lithography properties such as sensitivity, resolution, and LWR are also improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.

(Structural unit (a2))
The component (A) preferably further has a structural unit (a2) containing a lactone-containing cyclic group in addition to the structural unit (a1). The lactone cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A) is used for forming the resist film.
In addition, when the structural unit (a1) includes a lactone-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). However, such a structural unit is included in the structural unit (a1). Applicable and not applicable to the structural unit (a2).

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone-containing cyclic group in the structural unit (a2) is not particularly limited, and any lactone-containing cyclic group can be used. Specific examples include those represented by the following general formulas (a2-r-1) to (a2-r-7).

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

[Wherein, Ra ′ ²¹ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is 0 to 2 It is an integer and m ′ is 0 or 1. ]

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

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

(Structural unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (except for those corresponding to the structural units (a1) and (a2) described above).
When the component (A) has the structural 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, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom.
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. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.
The structural unit (a3) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group A structural unit is preferred.
The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid 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. 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), the formula ( The structural unit represented by a3-3) is preferred.

[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。]

[Wherein, R is as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In 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 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

The structural unit (a3) contained in the component (A) may be one type or two or more types.
In the component (A), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all the structural units constituting the component (A). 5 to 25 mol% is more preferable.
By setting the proportion of the structural unit (a3) to the lower limit value or more, the effect of including the structural unit (a3) can be sufficiently obtained, and by setting the proportion of the structural unit (a3) to the upper limit value or less, balance with other structural units can be obtained. It becomes easy.

The component (A) may contain other structural units (a4) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group is preferable. Examples of the cyclic group include those similar to those exemplified for the structural unit (a1), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those having the structures of the following general formulas (a4-1) to (a4-6). In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

［式中、Ｒ^αは前記と同じである。］

[Wherein, R ^α is the same as defined above. ]

  When the structural unit (a4) is contained in the component (A), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A). 10 to 20 mol% is more preferable.

Structural unit (a5)
The component (A) preferably further contains a structural unit (a5) containing a —SO ₂ -containing cyclic group. The —SO ₂ — containing cyclic group of the structural unit (a5) is effective for enhancing the adhesion of the resist film to the substrate when the component (A) is used for forming the resist film.
In addition, when the structural unit (a1) includes a —SO ₂ — containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a5). It corresponds to a1) and does not correspond to the structural unit (a5).
Here, the “—SO ₂ -containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, specifically, a sulfur atom in —SO ₂ — ( S) is a cyclic group that forms part of the ring skeleton of the cyclic group. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton A cyclic group containing a sultone ring to be formed is preferable. More specific examples of the —SO ₂ — containing cyclic group include structural units represented by the following general formulas (a5-r-1) to (a5-r-4).

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

[Wherein, Ra ′ ⁵¹ independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is 0 to 2 It is an integer. ]

In general formulas (a5-r-1) to (a5-r-4), A ″ represents an oxygen atom (—O—) or a sulfur atom (—S—), and may have 1 to 5 carbon atoms. The alkylene group having 1 to 5 carbon atoms in A ″ is preferably a linear or branched alkylene group, a methylene group, an ethylene group, an n-propylene group, An isopropylene group etc. are mentioned.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ⁵¹ , the —SO ₂ — containing cyclic group is as described above. Examples of the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group mentioned as the substituents that may be included are the same.
Specific examples of cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4) are shown below. In the formula, “Ac” represents an acetyl group.

As the —SO ₂ — containing cyclic group, among the above, a group represented by the general formula (a5-r-1) is preferable, and the chemical formulas (r-sl-1-1) and (r-sl— It is more preferable to use at least one selected from the group consisting of groups represented by 1-18), (r-sl-3-1) and (r-sl-4-1), The group represented by sl-1-1) is most preferred.

The structural unit (a5) is not particularly limited as long as it has a —SO ₂ — containing cyclic group, but may be a structural unit represented by the general formula (a5-1). preferable.

<Acid generator component; (B) component>
The component (B) is an acid generator component that generates an acid upon exposure.
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１０１は置換基を有していてもよい環式基、又は、置換基を有していてもよい鎖状のアルキル基若しくはアルケニル基であり、Ｙ^１０１は単結合または酸素原子を含む２価の連結基であり、Ｖ^１０１は単結合、アルキレン基、またはフッ素化アルキレン基である。
Ｒ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基であり、Ｒ^１０４、Ｒ^１０５は、それぞれ独立に、炭素数１〜１０のアルキル基またはフッ素化アルキル基であり、互いに結合して環を形成していてもよい。Ｍ^ｍ＋はｍ価の有機カチオンである。］

[Wherein, R ¹⁰¹ represents a cyclic group which may have a substituent, or a chain-like alkyl group or alkenyl group which may have a substituent, and Y ¹⁰¹ represents a single bond or an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group.
R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, and R ¹⁰⁴ and R ¹⁰⁵ are each independently an alkyl group having 1 to 10 carbon atoms or a fluorinated alkyl group, and are bonded to each other. A ring may be formed. M ^{m +} is an m-valent organic cation. ]

{Anion part}
The cyclic group which may have a substituent of R ¹⁰¹ may be a cyclic aliphatic hydrocarbon group (aliphatic cyclic group), or an aromatic hydrocarbon group (aromatic cyclic group). It may be a heterocycle containing a heteroatom in the ring.
Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aryl group obtained by removing one hydrogen atom from a monocycloalkane or polycycloalkane mentioned for the divalent aliphatic hydrocarbon group, and an adamantyl group and a norbornyl group are preferable.
Examples of the aromatic hydrocarbon group for R ¹⁰¹ include the aromatic hydrocarbon ring mentioned for the divalent aromatic hydrocarbon group, or an aryl group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings. A phenyl group and a naphthyl group are preferred.
Specific examples of the heterocyclic ring for R ¹⁰¹ include a lactone-containing cyclic group represented by the above general formulas (a2-r-1) to (a2-r-7), and the above general formula (a5-r-1) to (a5-r-4) represented by -SO ₂ - containing cyclic group, heterocycles include other below.

The cyclic aliphatic hydrocarbon group, aromatic hydrocarbon group and heterocyclic ring of R ¹⁰¹ may have a substituent. Here, the hydrocarbon ring or heterocycle has a substituent means that part or all of the hydrogen atoms bonded to the ring structure of the hydrocarbon ring or heterocycle are substituted with atoms or groups other than hydrogen atoms. Say.
Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a nitro group.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group. An ethoxy group is most preferred.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, or the like A group in which all the halogen atoms are substituted is exemplified.

The chain alkyl group for 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, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

The alkenyl group for R ¹⁰¹ preferably has 2 to 10 carbon atoms, preferably 2 to 5, more preferably 2 to 4, and particularly preferably 3. For example, a vinyl group, a propenyl group (allyl group), a butynyl group, etc. are mentioned. Among the above, a propenyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include, for example, the same alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, oxygen atom (═O), nitro as the substituent of the above cyclic group. Group, amino group; the above cyclic groups and the like.

In the present invention, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane, lactone-containing cyclic groups represented by a2-r-1) to (a2-r-7), —SO ₂ — represented by general formulas (a5-r-1) to (a5-r-4) above Containing cyclic groups, etc. are preferred.

The divalent linking group containing an oxygen atom of Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
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 amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group. A sulfonyl group (—SO ₂ —) may be further linked to the combination.
Examples of the combination, for ^{example, -V 105 -O -, - V} 105 -O-C (= O) -, - C (= O) -O-V 105 -O-C (= O) -, - SO _2- O—V ¹⁰⁵ —O—C (═O) —, —V ¹⁰⁵ —SO ₂ —O—V ¹⁰⁶ —O—C (═O) — (wherein V ^{105 to} V ¹⁰⁶ are each independently alkylene. Group.) And the like.
The alkylene group for V ^{105 to} V ¹⁰⁶ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Examples of the alkylene group include the same alkylene groups as those described above for V ¹⁰³ and V ¹⁰⁴ .
Q ^′ is preferably a divalent linking group containing an ester bond or an ether bond, and among them, —V ¹⁰⁵ —O—, —V ¹⁰⁵ —O—C (═O) — or —C (═O) — O—V ¹⁰⁵ —O—C (═O) — is preferable.

^Examples of the alkylene group for V ¹⁰¹ include the same alkylene groups as those described above for V ¹⁰³ and V ^104, and preferably have 1 to 5 carbon atoms.
^Examples of the fluorinated alkylene group for V ¹⁰¹ include those in which part or all of the hydrogen atoms constituting the alkylene group for V ¹⁰³ and V ¹⁰⁴ are substituted with fluorine atoms. It is preferable that it is C1-C5, and 1-2 is more preferable.

Examples of the fluorinated alkyl group having 1 to 5 carbon atoms of R ¹⁰² include groups in which some or all of the hydrogen atoms constituting the alkyl group having 1 to 5 carbon atoms are substituted with fluorine atoms.

R ¹⁰⁴ and R ¹⁰⁵ are each independently an alkyl group having 1 to 10 carbon atoms or a fluorinated alkyl group, and may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably linear or branched (fluorinated) alkyl groups. The (fluorinated) alkyl group has 1 to 10 carbon atoms, preferably 1 to 7 carbon atoms, and more preferably 1 to 3 carbon atoms. The number of carbon atoms of the (fluorinated) alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible because of good solubility in a resist solvent within the above carbon number range.
Further, in the (fluorinated) alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the transparency to high energy light and electron beams of 200 nm or less. This is preferable because of improved properties.
The proportion of fluorine atoms in the (fluorinated) alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are replaced with fluorine atoms. Perfluoroalkylene group or perfluoroalkyl group.

  Specific examples of the anion moiety represented by the formula (b-1) include anions represented by any of the following formulas (b1) to (b9).

［式中、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^１０７は置換基であり、ｎ１〜ｎ６はそれぞれ独立に０または１であり、ｖ０〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ¹⁰⁷ is a substituent, n1 to n6 are each independently 0 or 1, v0 to v6 are each independently an integer of 0 to 3, w1 to w6 are each independently an integer of 0 to 3, and Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —. , R ⁹⁴ and R ⁹⁵ are each independently an alkylene group having 1 to 5 carbon atoms, and m is an integer of 0 or 1.]

In the formula, the alkylene group in Q ″, R ⁹⁴ and R ⁹⁵ is preferably a methylene group.
^Examples of the substituent for R ¹⁰⁷ include the same groups as those described above for R ¹⁰¹ , which may substitute a part of the hydrogen atoms bonded to the ring structure of the cyclic group.
Code (r1 and r2, W1 to W6) attached to R ¹⁰⁷ when is an integer of 2 or more, plural ^{by R 107} in the compound may be the same, respectively, it may be different.

{Cation part}
M ^{m +} is an m-valent organic cation.
The m-valent organic cation in M ^{m +} is not particularly limited. For example, an organic cation conventionally known as a cation moiety such as an onium-based acid generator of a resist composition can be used.
The m-valent organic cation is preferably a sulfonium cation or an iodonium cation, and those represented by the following general formulas (ca-1) to (ca-4) are particularly preferable.

［式中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜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のいずれか２つ、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、
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。］

[Wherein, R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and any one of R ^{201 to} R ²⁰³ R ^{206 to} 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,
L ²⁰¹ represents —C (═O) — or —C (═O) O—,
Y ²⁰¹ each independently 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. ]

As the aryl group in R ²⁰¹ to R ^207, and ^R 210 ^{to R 212,} include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.

The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² is a chain / cyclic alkyl group, preferably having 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² preferably has 2 to 10 carbon atoms.

Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, an oxo group (═O), a cyano group, an amino group, Examples include aryl groups and substituents represented by the following formulas (ca-r-1) to (ca-r-7).

［式中、Ｒ’^２０１はそれぞれ独立に、水素原子、炭素数１〜３０の炭化水素基である。］

[Wherein, R ′ ²⁰¹ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ]

The hydrocarbon group for R ′ ^{201 is the same as} the cyclic group which may have a substituent for R ^{101 and} the chain alkyl group and alkenyl group which may have a substituent.
^{R 201 ~R 203, R 206 ~R} 207, R 211 ~R 212 , when bonded to each other to form a ring with the sulfur atom, a sulfur atom, an oxygen atom, or a hetero atom such as nitrogen atom, carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. You may couple | bond through the functional group of.
As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable.
Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, that is, a divalent or trivalent linking group.
Examples of the divalent linking group for W ^201, but are not limited to, divalent hydrocarbon group which may have a substituent group, and a divalent linking group containing a hetero atom as preferred.

(Divalent hydrocarbon group which may have a substituent)
The hydrocarbon group as the divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specific 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.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 5 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. 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 preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxo group (═O).

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those 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 polycyclic or monocyclic. As the monocyclic aliphatic 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 aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, Examples include norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

The aromatic hydrocarbon group as the divalent hydrocarbon group is a divalent hydrocarbon group having at least one aromatic ring and may have a substituent. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. 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 a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group as the divalent hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); A group in which two hydrogen atoms have been removed from an aromatic compound (for example, biphenyl, fluorene, etc.) containing one aromatic ring; a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or hetero group) A group in which one of the hydrogen atoms of the aryl group 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, etc. Group in which one hydrogen atom is further removed from the aryl group in the arylalkyl group); and the like. The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
The aromatic hydrocarbon group may or may not have a substituent. For example, a hydrogen atom bonded to an aromatic ring of the aromatic group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O). As the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group that replaces the hydrogen atom bonded to the aromatic ring, the alkyl group and alkoxy described above as the substituent of the hydrogen atom bonded to the cyclic aliphatic hydrocarbon group, respectively. Group, halogen atom, and halogenated alkyl group.

(Divalent linking group containing a hetero atom)
The hetero atom in the “divalent linking group containing a hetero atom” of the W ²⁰¹ is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
Examples of the divalent linking group containing a hetero atom include -O-, -C (= O) -O-, -C (= O)-, -O-C (= O) -O-, -C (= O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, —S (═O) _{2 -O -, - NH-C} (= O) -, = N-, the formula ^{-Y A -O-Y B -,} - [Y A -C (= O) -O] m '-Y B - , —C (═O) —O—Y ^B — or —Y ^A —O—C (═O) —Y ^B —, wherein Y ^A and Y ^B are each independently a substituent. Is a divalent hydrocarbon group which may have, O is an oxygen atom, and m ′ is an integer of 0-3. ] Etc. are mentioned.
When W ²⁰¹ is —NH—, H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, aryl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Y ^A and Y ^B are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as the "substituted divalent hydrocarbon group which may have a" in W ²⁰¹ above.
The Y ^A, preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, a linear alkylene group is more preferred, a methylene group or an ethylene group having 1 to 5 carbon atoms, especially preferable.
Y ^B is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, 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 ^A —C (═O) —O] _{m ′} —Y ^B —, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ^A —C (═O) —O] _{m ′} —Y ^B — is represented by the formula —Y ^A —C (═O) —O—Y ^B —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.
As the divalent linking group containing a hetero atom, a linear group having an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, is preferable, and the above formula —Y ^A —O—Y ^B —, ^A group represented by — [Y ^A —C (═O) —O] _{m ′} —Y ^B — or —Y ^A —O—C (═O) —Y ^B — is more preferable.

Among the above, as the divalent linking group of W ²⁰¹ , in particular, a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom is included. preferable. Among these, a linear or branched alkylene group or a divalent linking group containing an ester bond (—C (═O) —O—) is preferable.

^Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from a divalent linking group, a group in which a divalent linking group is further bonded to a divalent linking group, and the like. Examples of the divalent linking group include the same divalent linking group of the W ^201. The trivalent linking group in W ²⁰¹ is preferably a group in which three carbonyl groups are combined with an arylene group.

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

［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。］

[Wherein, g1, g2, and g3 represent 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、Ｒｄは水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[Wherein, Rd is a hydrogen atom or a substituent, and the substituent is the same as the substituent that may be possessed by R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² . ]

As the organic cation in M ^{m +,} the organic cation represented by the formula (c-1) or (c-3) is preferable.

As the oxime sulfonate acid generator, an oxime sulfonate acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chem. 18] to [Chem. 19]), International Publication An oxime sulfonate-based acid generator disclosed in the pamphlet of No. 04/074242 (Examples 1 to 40 on pages 65 to 86) can be preferably used.
As the diazomethane acid generator, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, as for content of (B) component in a solvent development negative resist composition, 1-50 mass parts is more preferable, and 1-40 Part by mass is more preferable. By forming the content of the component (B) within the above range, pattern formation is sufficiently performed. Moreover, when each component of a solvent development negative resist composition is melt | dissolved in the organic solvent, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<Basic compound component; (D) component>
The component (D) is a basic compound component, and acts as an acid diffusion control agent, that is, a quencher that traps acid generated from the component (B) by exposure. In the present invention, the “basic compound” refers to a compound that is relatively basic with respect to the component (B). (D) component in this invention contains the basic compound component (D1) (henceforth "(D1) component") which has a fluorine atom.

[(D1) component]
The component (D1) in the present invention is not particularly limited as long as it is relatively basic with respect to the component (B), but includes a compound composed of a cation part and an anion part. Preferably, it contains a photoreactive quencher, more preferably a compound (d1) represented by the following general formula (d1) (hereinafter referred to as component (d1)), a compound represented by the following general formula (d2) ( d2) containing at least one compound selected from the group consisting of (hereinafter referred to as component (d2)) and compound (d3) represented by the following general formula (d3) (hereinafter referred to as component (d3)). Is more preferable. The “photoreactive quencher” does not act as a quencher in the exposed part, but acts as a quencher in the unexposed part.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい炭化水素基である。ただし、式（ｄ２）において、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はアルキレン基又はアリーレン基であり、Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

^Wherein, Rd 1 ^{~Rd 4} is a hydrocarbon group which may have a substituent. However, in the formula (d2), it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom.
Yd ¹ is an alkylene group or an arylene group, and M ^{m +} is each independently an m-valent organic cation. ]

[(D1) component]
Anion formula (d1), Rd ¹ represents a hydrocarbon group which may have a substituent.
The hydrocarbon group which may have a substituent of Rd ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the aliphatic hydrocarbon group of X in component (B) And the same as the aromatic hydrocarbon group.
Among them, the hydrocarbon group which may have a substituent of Rd ¹ is an aromatic hydrocarbon group which may have a substituent, or an aliphatic cyclic group which may have a substituent. A phenyl group or naphthyl group which may have a substituent; one or more hydrogen atoms are removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. More preferably, it is a group.

Further, the hydrocarbon group which may have a substituent of Rd ¹ is preferably a linear, branched, or alicyclic alkyl group, or a fluorinated alkyl group.
The linear, branched or alicyclic alkyl group of Rd ¹ preferably has 1 to 10 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, Linear alkyl group such as hexyl group, heptyl group, octyl group, nonyl group, decyl group, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group A branched alkyl group such as 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, norbornyl group And alicyclic alkyl groups such as an adamantyl group.

The fluorinated alkyl group for Rd ¹ may be linear or cyclic, but is preferably linear or branched.
1-11 are preferable, as for carbon number of a fluorinated alkyl group, 1-8 are more preferable, and 1-4 are more preferable. Specifically, for example, a part or all of a linear alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Or a branched chain such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, or a 3-methylbutyl group. And a group in which some or all of the hydrogen atoms constituting the alkyl group are substituted with fluorine atoms.
The fluorinated alkyl group for Rd ¹ may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Among them, the fluorinated alkyl group for Rd ¹ is preferably a group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms. It is preferable that all the hydrogen atoms which comprise are the group (perfluoroalkyl group) substituted by the fluorine atom.

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

-Cation part In Formula (d1), M ^<+> is an organic cation.
Although it does not specifically limit as an organic cation of M ^<+> , For example, the cation part represented by the said Formula (ca-1)-(ca-4) is mentioned.
As the component (d1), one type may be used alone, or two or more types may be used in combination.

[(D2) component]
Anion formula (d2), Rd ² is a hydrocarbon group of 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have a substituent of Rd ² may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and in the formula (b1), Examples are the same as the aliphatic hydrocarbon group and aromatic hydrocarbon group of X.
Among them, the hydrocarbon group which may have a substituent of Rd ² is preferably an aliphatic cyclic group which may have a substituent, such as adamantane, norbornane, isobornane, tricyclodecane, It is more preferably a group obtained by removing one or more hydrogen atoms from tetracyclododecane, camphor or the like (which may have a substituent).
The hydrocarbon group for Rd ² may have a substituent, and examples of the substituent include the same as X in the component (B). However, in Rd ² , the carbon adjacent to the S atom in SO ₃ ^— is not fluorine-substituted. Since SO ₃ ^— and a fluorine atom are not adjacent to each other, the anion of the component (d2) becomes an appropriate weak acid anion, and the quenching ability of the component (D) is improved.
Preferred specific examples of the anion moiety of the component (d2) are shown below.

· Cation In formula (d2), ^{M +} is the same as ^{M +} in the formula (d1) in.
As the component (d2), one type may be used alone, or two or more types may be used in combination.

[(D3) component]
Anion formula (d3), Rd ⁴ is an organic group.
The organic group of Rd ⁴ is not particularly limited, but an alkyl group, an alkoxy group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 is a hydrogen atom, and has 1 to 5 carbon atoms. Or an alkyl group having 1 to 5 carbon atoms), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group).
The alkyl group of Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group of Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are most preferable.

When Rd ⁴ is —O—C (═O) —C (R ^C2 ) ═CH ₂ , R ^C2 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. is there.
The alkyl group having 1 to 5 carbon atoms in R ^C2 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n -Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like can be mentioned.
The halogenated alkyl group in R ^C2 is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R ^C2 is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fluorinated alkyl group having 1 to 3 carbon atoms, and is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

When Rd ⁴ is —O—C (═O) —R ^C3 , R ^C3 is a hydrocarbon group.
The hydrocarbon group for R ^C3 may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Specific examples of the hydrocarbon group for R ^C3 include the same hydrocarbon groups as those for X in the component (B).
Among them, as the hydrocarbon group of R ^C3 , an alicyclic group in which one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like, Aromatic groups such as phenyl group and naphthyl group are preferred. When R ^C3 is an alicyclic group, the solvent-developed negative resist composition dissolves well in an organic solvent, so that the lithography properties are improved. Further, when R ^C3 is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

Among them, as Rd ⁴ , —O—C (═O) —C (R ^C2 ′) ═CH ₂ (R ^C2 ′ is a hydrogen atom or a methyl group), or —O—C (═O ) -R ^C3 ′ (R ^C3 ′ is an aliphatic cyclic group).

In formula (d3), Yd ¹ represents a linear, branched or cyclic alkylene group or an arylene group.
Yd ¹ linear, the branched or cyclic alkylene group or arylene group, among the divalent linking group W ²⁰¹ in formula (ca-4), "linear or branched Examples thereof include the same as “aliphatic hydrocarbon group”, “cyclic aliphatic hydrocarbon group”, and “aromatic hydrocarbon group”.
Among these, Yd ¹ is preferably an alkylene group, more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

In the formula (d3), Rd ³ is a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom of Rd ³ is preferably a fluorinated alkyl group, and more preferably the same as the fluorinated alkyl group of Rd ¹ .
Preferred specific examples of the anion moiety of the component (d3) are shown below.

· Cation In formula (d3), ^{M +} is the same as ^{M +} in the formula (d1) in.
As the component (d3), one type may be used alone, or two or more types may be used in combination.

The component (D1) may contain only one of the above components (d1) to (d3), or may contain two or more in combination.
The total content of the components (d1) to (d3) is preferably 0.5 to 10.0 parts by mass with respect to 100 parts by mass of the component (A), and 0.5 to 8.0 parts by mass. It is more preferable that it is 1.0 to 8.0 parts by mass. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

(Production method of component (D1))
The production method of the component (d1) and the component (d2) in the present invention is not particularly limited, and can be produced by a known method.
Further, the production method of the component (d3) is not particularly limited. For example, when Rd ⁴ in the formula (d3) is a group having an oxygen atom at the terminal bonded to Yd ¹ , the following general formula By reacting the compound (i-1) represented by the formula (i-1) with the compound (i-2) represented by the following general formula (i-2), the following general formula (i-3) The compound (i-3) represented by the formula (d3) is reacted with the compound (i-3) and Z ⁻ M ⁺ (i-4) having the desired cation M ^+. The compound (d3) represented by these is manufactured.

［式中、Ｒ^２、Ｙ^３、Ｒｆ、Ｍ^＋は、それぞれ、前記一般式（ｄ３）中のＲｄ^４、Ｙｄ^１、Ｒｄ^３、Ｍ^＋と同じである。Ｒ^２ａはＲ^２から末端の酸素原子を除いた基であり、Ｚ⁻は対アニオンである。］

[Wherein, R ² , Y ³ , Rf, and M ⁺ are the same as Rd ⁴ , Yd ¹ , Rd ³ , and M ^{+ in the} general formula (d3), respectively. R ^2a is a group obtained by removing a terminal oxygen atom from R ² , and Z ⁻ is a counter anion. ]

First, compound (i-1) and compound (i-2) are reacted to obtain compound (i-3).
In these formulas, R ² is the same as described above, and R ^2a is a group obtained by removing a terminal oxygen atom from R ² . In formula (i-2), Y ³ and Rf are the same as described above.
As compound (i-1) and compound (i-2), commercially available compounds may be used or synthesized.
The method for obtaining compound (i-3) by reacting compound (i-1) with compound (i-2) is not particularly limited. For example, compound (i-) can be obtained in the presence of an appropriate acid catalyst. After reacting 2) and compound (i-1) in an organic solvent, the reaction mixture can be washed and recovered.

The acid catalyst in the said reaction is not specifically limited, For example, toluenesulfonic acid etc. are mentioned, The usage-amount is about 0.05-5 mol with respect to 1 mol of compounds (i-2).
The organic solvent in the above reaction may be any material that can dissolve the compound (i-1) and the compound (i-2) as raw materials, and specifically includes toluene and the like. It is preferable that it is 0.5-100 mass parts with respect to (i-1), and it is more preferable that it is 0.5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-2) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, per 1 mol of compound (i-1).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-1) and the compound (i-2), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.

Next, the obtained compound (i-3) and the compound (i-4) are reacted to obtain the compound (d1-3).
In formula (i-4), M ⁺ is the same as described above, and Z ⁻ is a counter anion.
The method of reacting compound (i-3) and compound (i-4) to obtain compound (d1-3) is not particularly limited. For example, the compound is obtained in the presence of a suitable alkali metal hydroxide. It can be carried out by dissolving (i-3) in a suitable organic solvent and water, adding compound (i-4) and reacting with stirring.

The alkali metal hydroxide in the above reaction is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide and the like. About 3 mol is preferable.
Examples of the organic solvent in the above reaction include solvents such as dichloromethane, chloroform, and ethyl acetate, and the amount used is preferably 0.5 to 100 parts by mass with respect to compound (i-3). More preferably, it is 5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-4) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, relative to 1 mol of compound (i-3).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-3) and the compound (i-4), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.
After completion of the reaction, the compound (d3) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof. it can.

The structure of the compound (d3) obtained as described above is as follows: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass It can be confirmed by a general organic analysis method such as analysis (MS) method, elemental analysis method or X-ray crystal diffraction method.

  The content of the component (D1) is preferably 0.5 to 10.0 parts by mass and more preferably 0.5 to 8.0 parts by mass with respect to 100 parts by mass of the component (A). 1.0 to 8.0 parts by mass is even more preferable. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

[(D2) component]
(D) component may contain the other basic compound component (henceforth (D2) component) which does not correspond to the said (D1) component.
The component (D2) is particularly limited as long as it is a compound that is relatively basic with respect to the component (B), acts as an acid diffusion controller, and does not fall under the component (D1). It may be used arbitrarily from known ones. Of these, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol 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 , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

  Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, 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, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine may be used.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

(D2) A component may be used independently and may be used in combination of 2 or more type.
(D2) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
When the solvent development negative resist composition contains the component (D), the component (D) is preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the component (A), and 0.3 More preferably, it is -12 mass parts, and it is further more preferable that it is 0.5-12 mass parts. When it is at least the lower limit of the above range, lithography properties such as roughness are further improved when a solvent-developed negative resist composition is used. Further, a better resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

<Optional component>
[(E) component]
Solvent-developed negative resist compositions include organic carboxylic acids and phosphorus oxoacids and their derivatives as optional components for the purpose of preventing sensitivity deterioration and improving resist pattern shape and stability over time. At least one compound (E) selected from the group (hereinafter referred to as component (E)) 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 phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

[(S) component]
The solvent-developed negative resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as the (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol Polyhydric alcohols such as: ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate and the like compounds having an ester bond, the polyhydric alcohols or monomethyl ether of the compound having an ester bond , Monoalkyl ethers such as monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and lactic acid Esters such as methyl, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, Diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. An aromatic organic solvent, dimethyl sulfoxide (DMSO), etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be 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. . Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
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 mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

[Production of polymer compounds 1 to 4]
Polymer compounds 1 to 4 were synthesized by a conventional method using the following monomers (1) to (8) for deriving structural units constituting each polymer compound in the molar ratio shown in Table 1. The molecular weight (Mw) and molecular weight dispersion (Mw / Mn) of the obtained polymer compound are also shown in Table 1.

  Each component shown in Table 2 was mixed and dissolved to prepare a solvent-developed negative resist composition.

Each abbreviation in Table 2 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1 to (A) -4: The above polymer compounds 1 to 4.
(B) -1 to (B) -3: The following compounds (B-1) to (B-3).
(C) -1: The following compound (C-1).
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: PGMEA.
(S) -2: cyclohexanone.

[Formation of resist pattern]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed.
Next, a resin composition (styrene / methacrylic acid 3,4-epoxycyclohexylmethane / methacrylic acid) adjusted to a concentration of 0.5 to 1.0 mass% using PGMEA as a base agent on the organic antireflection film. A propyltrimethoxysilane acid = 75/20/5 copolymer having a molecular weight of 40,000) is applied using a spinner, baked at 250 ° C. for 1 minute, and dried to form a base material having a film thickness of 10 nm. A layer was formed on the substrate.
Then, the resist composition of each example is applied onto the layer made of the base agent using a spinner, and on the hot plate, the resists 1 to 3 are 105 ° C. for 60 seconds, and the resist 4 is 80 ° C. for 60 seconds. A pre-bake (PAB) treatment was performed under the conditions described above and dried to form a resist film having a thickness of 100 nm.
Next, ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon; NA (numerical aperture) = 1.07, Cross pole (in / out = 0.78 / 0.97) with Polano), ArF excimer laser, Irradiated. The resists 1 to 3 were subjected to PEB treatment at 95 ° C. for 60 seconds, and the resist 4 was subjected to PEB treatment at 125 ° C. for 60 seconds. Paddle development was performed for 16 seconds with butyl acetate at 23 ° C., and then shaken and dried. Subsequently, the resists 1 to 3 were post-baked on a hot plate at 100 ° C. for 1 minute, and the resist 4 was 200 ° C. for 300 seconds.
As a result, in Examples 1-2, and 5, a 1: 1 line and space (LS) pattern having a line width of 95 nm and a pitch width of 95 nm was formed on the resist film. In Examples 3 to 4, 6 and Reference Example 1, a hole pattern having a hole diameter of 85 nm was formed on the resist film.

Then, the composition shown in Table 3 was spin-coated on the substrate on which the resist pattern was formed under the condition that the film thickness was 20 nm on the silicon substrate.
Thereafter, a heat treatment was performed at a temperature and time shown in Table 3 under a nitrogen stream to form a phase separation structure. The substrate on which phase separation is formed is subjected to oxygen plasma treatment (200 mL / min, 40 Pa, 40 ° C., 200 W, 20 seconds) using TCA-3822 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) to selectively select a phase composed of PMMA. The surface of the obtained substrate was observed with a scanning electron microscope SU8000 (manufactured by Hitachi High-Technologies Corporation). For Examples 1-2, 5 and 5 in which a 1: 1 line and space (LS) pattern having a line width of 14 nm and a pitch width of 14 nm was formed, in Examples 3 to 4, and 6, on the resist film, A case where a hole pattern with a hole diameter of 20 nm was formed was marked as ◯. The results are shown in Table 3.

Each abbreviation in Table 2 has the following meaning.
(BP) -1: Block copolymer of PS-PMMA (Mw = 18000-18000, Mw / Mn = 1.07).
(BP) -2: Block copolymer of PS-PMMA (Mw = 45000-20000, Mw / Mn = 1.07).

  From the above results, using a resist pattern of a solvent-developed negative resist composition having no 3- to 7-membered ether-containing cyclic group, a solvent-developed negative type having a 3- to 7-membered ether-containing cyclic group A phase separation pattern equivalent to that obtained when the resist pattern of the resist composition was used could be formed.

11 ... substrate, a layer consisting of 12 ... undercoat agent, 14 ... resist pattern, a layer containing 13 ... block copolymer, a phase consisting of 13a ... _{P B} block, phase consisting 13b ... _{P A} block

Claims (4)

A base material component (A) whose solubility in an organic solvent is reduced by the action of an acid and a solvent-developed negative resist composition containing an acid generator component (B) that generates an acid upon exposure are coated on a support. And forming a resist film,
Exposing the resist film;
Developing the resist film using a developer containing the organic solvent to form a resist pattern;
Forming a layer containing a block copolymer to which a plurality of types of blocks are bonded on a support on which the resist pattern is formed, and then phase-separating the layer containing the block copolymer;
A step of selectively removing a phase consisting of at least one of a plurality of types of blocks constituting the block copolymer from the layer containing the block copolymer, and a pattern forming method comprising:
The pattern forming method, wherein the substrate component (A) does not have a 3- to 7-membered ether-containing cyclic group.   A layer containing the block copolymer, a block copolymer in which a plurality of types of blocks are bonded, a compound having a vapor pressure at 20 ° C. of 0.05 hPa or less and a freezing point of 25 ° C. or less, and an organic solvent not corresponding to the compound The pattern formation method of Claim 1 formed using the composition containing these.   The pattern formation method according to claim 2, wherein the molecular weight of the compound having a vapor pressure at 20 ° C. of 0.05 hPa or less and a freezing point of 25 ° C. or less is 600 or less.   The pattern forming method according to claim 2 or 3, wherein a static surface tension of a compound having a vapor pressure at 20 ° C of 0.05 hPa or less and a freezing point of 25 ° C or less is 30 mN / m or more.

Images