JP2010250263A - Method for forming resist pattern and resin composition for insolubilizing resist pattern used for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a resist pattern, with which a finer resist pattern with a controlled line width change can be formed readily and efficiently, while reducing the occurrence of damages. <P>SOLUTION: The method for forming a resist pattern includes a step (1) of forming an insolubilized resist pattern, by using a resin composition for insolubilizing a resist pattern, the composition containing a polymer having a repeating unit expressed by formula (1) (wherein R<SP>1</SP>represents a hydrogen atom, or the like, and R<SP>2</SP>represents a methylene group, or the like) and a solvent; a step (2) of forming a resist layer on a substrate, where the insolubilized resist pattern is formed and selectively exposing the resist layer; and a step (3) of forming a second resist pattern. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resist pattern forming method capable of easily and efficiently forming a finer resist pattern, and a resist pattern insolubilized resin composition used therein that can insolubilize a resist pattern.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, lithography technology capable of microfabrication at a level of 0.10 μm or less is required. In the conventional lithography process, near ultraviolet rays such as i-line are generally used as radiation, and it is said that fine processing at the subquarter micron level is extremely difficult with this near ultraviolet rays. Therefore, in order to enable fine processing at a level of 0.10 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, X-rays, and electron beams. Among these, KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm) are attracting attention.

  As a resist suitable for irradiation with such an excimer laser, a component having an acid-dissociable functional group and a component that generates acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “acid generator”) Many resists (hereinafter referred to as “chemically amplified resists”) that utilize the chemical amplification effect of the above have been proposed. As the chemically amplified resist, for example, a resist containing a resin having a t-butyl ester group of carboxylic acid or a t-butyl carbonate group of phenol and an acid generator has been proposed (for example, Patent Document 1). reference). In this resist, the t-butyl ester group or t-butyl carbonate group present in the resin is dissociated by the action of an acid generated by exposure, and the resin has an acidic group composed of a carboxyl group or a phenolic hydroxyl group. As a result, the phenomenon that the exposure region of the resist film becomes readily soluble in an alkali developer is utilized.

  In such a lithography process, further fine pattern formation (for example, a fine resist pattern having a line width of about 45 nm) will be required in the future. In order to achieve such a finer pattern formation, it is conceivable to shorten the light source wavelength of the exposure apparatus and increase the numerical aperture (NA) of the lens as described above. However, in order to shorten the light source wavelength, a new expensive exposure apparatus is required. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

  In recent years, a liquid immersion lithography (liquid immersion lithography) method has been disclosed as a lithography technique that can solve such problems (for example, see Patent Document 2). In this method, at the time of exposure, a liquid high refractive index medium (immersion exposure liquid) such as pure water or fluorine-based inert liquid having a predetermined thickness is formed on at least the resist film between the lens and the resist film on the substrate. It is a method of interposing. According to this method, a light source having the same exposure wavelength is used by replacing the exposure optical path space, which has conventionally been an inert gas such as air or nitrogen, with a liquid having a higher refractive index (n), such as pure water. However, as in the case of using a light source with a shorter wavelength or the case of using a high NA lens, high resolution is achieved and there is no reduction in the depth of focus. That is, according to this method, using a lens mounted on an existing apparatus, it is possible to realize a resist pattern that is low in cost, excellent in resolution, and excellent in depth of focus. It is being put to practical use.

  However, it is said that the above-described advancement of the exposure technique is limited to 45 nmhp, and technical development for the 32 nmhp generation that requires further fine processing is being carried out. In recent years, in accordance with the demand for higher complexity and higher density of such devices, a technique for patterning 32 nm LS by overlapping half-cycles of sparse line patterns or isolated trench patterns such as double patterning or double exposure has been proposed. (For example, refer nonpatent literature 1).

  In Non-Patent Document 1, a 32 nm line having a pitch of 1: 3 is formed and then processed by etching, and a 32 nm line having a pitch of 1: 3 is similarly formed at a position shifted by a half period from the first resist pattern. It is disclosed that it is formed and processed again by etching to finally form a 32 nm line with a 1: 1 pitch.

Japanese Patent Laid-Open No. 5-232704 JP-A-10-303114

SPIE 2006 Vol. 6153 6153K

  However, although there are proposals for several processes as described above, no proposals for more specific and practical methods and materials have been made yet.

  The present invention has been made in view of such problems of the prior art, and the problem is that the line width variation of the resist pattern to be formed can be controlled and is generated in the resist pattern. The object is to provide a resist pattern insolubilized resin composition capable of reducing damage.

  Another object of the present invention is to provide a resist pattern forming method capable of easily and efficiently forming a finer resist pattern whose line width variation is controlled while reducing the occurrence of damage. is there.

  As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention include a polymer having a specific repeating unit as a resist pattern insolubilized resin composition capable of insolubilizing a resist pattern, and a resist pattern curing action. It was found that the above-mentioned problems can be achieved by using a material improved in the invention, and the present invention has been completed.

  That is, according to the present invention, the following resist pattern forming method and resist pattern insolubilizing resin composition are provided.

  [1] A resist pattern insolubilized resin composition containing a polymer containing a repeating unit represented by the following general formula (1) and a solvent is applied onto a first resist pattern formed on a substrate, and baked. Alternatively, after UV curing, washing to insolubilize the first resist pattern in a developer and a radiation-sensitive resin composition to form an insolubilized resist pattern on the substrate (1); Using the radiation resin composition, a resist layer is formed on the substrate on which the insolubilized resist pattern is formed, the step (2) of selectively exposing the resist layer, and developing to form a second resist pattern. And a step (3) of forming a resist pattern.

In the general formula (1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² represents a single bond, a methylene group, or a linear or branched alkylene having 2 to 6 carbon atoms. Group or an alicyclic hydrocarbon group having 4 to 12 carbon atoms.

  [2] A resist pattern insolubilizing resin composition containing a polymer containing a repeating unit represented by the following general formula (1) and a solvent used in step (1) of the resist pattern forming method according to [1] above object.

In the general formula (1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² represents a single bond, a methylene group, or a linear or branched alkylene having 2 to 6 carbon atoms. Group or an alicyclic hydrocarbon group having 4 to 12 carbon atoms.

  [3] The resist pattern insolubilized resin composition according to [2], wherein the polymer further includes a repeating unit derived from a monomer represented by the following general formula (2).

In the general formula (2), R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and A is a single bond or a linear or branched alkylene group having 1 to 5 carbon atoms. , -NH-, -O-, -COO-, or -CONH-R ^5- , m is 1 or 2, and n is an integer of 0-2. R ⁵ represents a single bond or a linear, branched or cyclic divalent hydrocarbon group.

  [4] The resist pattern insolubilized resin composition according to [2] or [3], wherein the solvent is an alcohol solvent.

  According to the resist pattern forming method of the present invention, it is possible to easily and efficiently form a resist pattern with finer and controlled line width variation while reducing the occurrence of damage.

  The resist pattern insolubilized resin composition of the present invention has the effect of being able to control the line width variation of the resist pattern to be formed and to reduce damage occurring in the resist pattern.

It is sectional drawing which shows an example of the 1st resist pattern formed on the board | substrate. It is sectional drawing which shows an example of the state which made the 1st resist pattern the insolubilization resist pattern in process (1) of the resist pattern formation method concerning this invention. In the process (1) of the resist pattern formation method which concerns on this invention, it is a schematic diagram which shows an example of the state which used the 1st resist pattern as the insolubilized resist pattern. It is sectional drawing which shows an example of the state which formed the resist layer on the insolubilized resist pattern in the process (2) of the resist pattern formation method which concerns on this invention. It is a schematic diagram which shows an example of the state which formed the 2nd resist pattern in the process (3) of the resist pattern formation method concerning this invention. It is a schematic diagram which shows the other example of the state in which the 2nd resist pattern was formed in the process (3) of the resist pattern formation method concerning this invention. It is a schematic diagram which shows the further another example of the state in which the 2nd resist pattern was formed in process (3) of the resist pattern formation method concerning this invention. It is a side view which shows an example of the state which formed the 2nd resist pattern in the process (3) of the resist pattern formation method concerning this invention.

  Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

  In the present specification, “(meth) acrylic acid” means both acrylic acid and methacrylic acid. In the present specification, “(meth) acrylate” means both acrylate and methacrylate.

1. Resist pattern insolubilized resin composition:
The resist pattern insolubilized resin composition of the present invention (hereinafter also simply referred to as “insolubilized resin composition”) contains a polymer containing a repeating unit represented by the general formula (1) and a solvent. . Further, the insolubilized resin composition of the present invention is formed on the substrate by insolubilizing the first resist pattern with respect to the developer and the radiation-sensitive resin composition in “Step (1)” of the resist pattern forming method described later. It is used to form an insolubilized resist pattern. The details will be described below.

(Polymer)
(Repeating unit (1))
The polymer contained in the insolubilized resin composition of the present invention contains a repeating unit represented by the following general formula (1) (hereinafter also referred to as “repeating unit (1)”).

In the general formula (1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² represents a single bond, a methylene group, or a linear or branched alkylene having 2 to 6 carbon atoms. Group or an alicyclic hydrocarbon group having 4 to 12 carbon atoms. However, R ² may be an alkylene glycol group or an alkylene ester group.

In the general formula (1), preferable examples of the group represented by R ² include methylene group, ethylene group, 1,3-propylene group, 1,2-propylene group and other propylene groups, tetramethylene group, and pentane. Methylene group, hexamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group Saturated chain hydrocarbon groups such as 2-methyl-1,4-butylene group, methylidene group, ethylidene group, 1-propylidene group and 2-propylidene group; cyclobutylene groups such as 1,3-cyclobutylene group, 1 A cyclopentylene group such as 1,3-cyclopentylene group, a cyclohexylene group such as 1,4-cyclohexylene group, a cyclooctylene group such as 1,5-cyclooctylene group and the like having 3 to 10 carbon atoms. Monocyclic hydrocarbon ring groups such as chloralkylene groups; norbornylene groups such as 1,4-norbornylene groups and 2,5-norbornylene groups, adamantylene groups such as 1,5-adamantylene groups and 2,6-adamantylene groups Examples thereof include a crosslinked cyclic hydrocarbon ring group such as a 2-4 cyclic hydrocarbon ring group having 4 to 12 carbon atoms such as a group. Of these, a hydrocarbon group containing 2,5-norbornylene group, an ethylene group, and a propylene group are more preferable.

When R ² in the general formula (1) is a divalent alicyclic hydrocarbon group, the divalent alicyclic hydrocarbon group and a bis (trifluoromethyl) hydroxymethyl group (— between _{C (CF 3) 2 OH)} , it is preferable that the alkylene group having 1 to 4 carbon atoms is introduced as a spacer.

Preferable examples of the monomer (hereinafter, also referred to as “monomer (1)”) used for constituting the repeating unit (1) include (meth) acrylic acid (3,3,3-trifluoro- 2-trifluoromethyl-2-hydroxypropyl) ester, (meth) acrylic acid (4,4,4-trifluoro-3-trifluoromethyl-3-hydroxybutan-1-yl) ester, (meth) acrylic acid (5,5,5-trifluoro-4-trifluoromethyl-4-hydroxypentan-1-yl) ester, (meth) acrylic acid (5,5,5-trifluoro-4-trifluoromethyl-4- Hydroxypentan-2-yl) ester, (meth) acrylic acid (5- (3,3,3-trifluoro-2-trifluoromethyl-2-hydroxypropyl) bicyclo [2.2.1 Heptane-1-yl) ester, (meth) acrylic acid (8- (3,3,3-trifluoro-2-trifluoromethyl-2-hydroxypropyl) tetracyclo [6.2.1.1 ^{3, 6. 0,7} ] dodecan-1-yl) ester and the like. In addition, the polymer may contain only one type of repeating unit (1), or may contain two or more types of repeating units (1).

(Monomer (2))
The polymer contained in the insolubilized resin composition of the present invention is a repeating unit derived from hydroxy (meth) acrylanilide represented by the following general formula (2) (hereinafter also referred to as “repeating unit (2)”). It is preferable to include.

In the general formula (2), R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and A is a single bond or a linear or branched alkylene group having 1 to 5 carbon atoms. , -NH-, -O-, -COO-, or -CONH-R ^5- , m is 1 or 2, and n is an integer of 0-2. R ⁵ represents a single bond or a linear, branched or cyclic divalent hydrocarbon group. Note that —COO— and —CONH—R ⁵ — may be bonded in any direction. That is, for example, in the case of -COO-, any of a carbonyloxy group and an oxycarbonyl group may be bonded to the double bond carbon.

  In the general formula (2), among the groups represented by A, specific examples of the linear or branched alkylene group having 1 to 5 carbon atoms include a methylene group, an ethylene group, and a 1,3-propylene group. 1,2-propylene group, 1,4-butylene group, 1,3-butylene group, 1,2-butylene group, 1,5-pentylene group, 1,4-pentylene group, 1,3-pentylene group, Saturated chain hydrocarbon groups such as 1,2-pentylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 2,2-dimethyl-1,3-propylene group, etc. Can be mentioned.

Specific examples of the linear, branched or cyclic divalent hydrocarbon group among the groups represented by R ⁵ include a methylene group, an ethylene group, a 1,3-propylene group, and a 1,2-propylene. Group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group Group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, icosalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl -1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, ethylidene group, 1-pro Saturated chain hydrocarbon group such as pyridene group and 2-propylidene group; cyclobutylene group such as 1,3-cyclobutylene group, cyclopentylene group such as 1,3-cyclopentylene group, 1,4-cyclohexylene A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms, such as a cyclohexylene group such as a group, a cyclooctylene group such as a 1,5-cyclooctylene group, and the like; 1,4-norbornylene Carbon atoms having 2 to 4 cyclic carbon atoms including adamantylene groups such as 1,5-norbornylene groups such as 2,5-norbornylene groups, 1,5-adamantylene groups and 2,6-adamantylene groups Examples thereof include a bridged cyclic hydrocarbon ring group such as a hydrogen ring group. These monomers (2) can be used individually by 1 type or in combination of 2 or more types.

  The ratio of the repeating unit (2) contained in the polymer is preferably 10 to 90 mol%, more preferably 15 to 70 mol%, in 100 mol% of all repeating units. When the content ratio of the repeating unit (2) is less than 10 mol%, the number of reaction sites with the crosslinking component described later becomes too small, so that the resist pattern is less likely to shrink. On the other hand, if the content ratio of the repeating unit (2) is more than 90 mol%, the insolubilized resin composition may swell during development, and the space portion of the resist pattern may be buried. That is, when the ratio of the repeating unit (2) contained in the polymer is outside the above range, it may be difficult to control the line width variation of the insolubilized resist pattern formed using the insolubilized resin composition. .

(Other repeat units)
In the polymer, in addition to the repeating unit (1) and the repeating unit (2), a repeating unit derived from at least one selected from the group consisting of monomers (3) to (8) shown below ( Other repeating units) may be included.

(Monomer (3))
The monomer (3) is a styrene derivative represented by the following general formula (3).

In the general formula (3), R ⁶ is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkoxyl group having 1 to 8 carbon atoms, or 2 carbon atoms. -9 linear or branched alkoxycarbonyloxy group, a C6-C20 aryl group, or a C7-C20 aralkyl group is shown.

Specific examples of the linear or branched alkyl group having 1 to 8 carbon atoms among the groups represented by R ⁶ in the general formula (3) include a methyl group, an ethyl group, a 1-propyl group, 2-propyl group, 1-butyl group, 2-butyl group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 2-methyl-1-propyl group, 2,2-dimethyl-1-propyl group, etc. Can be mentioned.

Among the groups represented by R ⁶ in the general formula (3), specific examples of the linear or branched alkoxyl group having 1 to 8 carbon atoms include a t-butoxy group, an acetoxy group, an ethoxy group, and the like. Can be mentioned.

Specific examples of the linear or branched alkoxycarbonyloxy group having 2 to 9 carbon atoms among the groups represented by R ⁶ in the general formula (3) include a t-butoxycarbonyloxy group, methoxycarbonyl An oxy group etc. can be mentioned.

Among the groups represented by R ⁶ in the general formula (3), specific examples of the aryl group having 6 to 20 carbon atoms include a phenyl group and a naphthyl group.

Among the groups represented by R ⁶ in the general formula (3), specific examples of the aralkyl group having 7 to 20 carbon atoms include benzyl group, phenylethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group. Etc.

  The monomer (3) is preferably a styrene derivative having a specific functional group that can be converted to a phenolic hydroxyl group after copolymerization. Specific examples of such a styrene derivative having a specific functional group include p-acetoxystyrene, m-acetoxystyrene, α-methyl-p-acetoxystyrene, pt-butoxystyrene, pt-butoxycarbonyloxy. Examples thereof include styrene. These styrene derivatives can be used alone or in combination of two or more. In addition, after copolymerizing these styrene derivatives, if it hydrolyzes using hydrochloric acid etc., a specific functional group can be easily converted into a phenolic hydroxyl group.

  The ratio of the repeating unit derived from the monomer (3) contained in the polymer is preferably 5 to 65 mol%, more preferably 10 to 50 mol%, in 100 mol% of all repeating units.

(Monomer (4))
Specific examples of the monomer (4) include glycidyl methacrylate, glycidyl acrylate, (3-ethyl-3-oxetanyl) methyl methacrylate (trade name “OXMA”, manufactured by Ube Industries), 2-[(3,5- Dimethylpyrazolyl) carbonylamino] ethyl methacrylate (trade name “MOI-BP”, manufactured by Showa Denko KK), 2- [0- (1-methylpropylideneamino) carbonylamino] ethyl methacrylate (trade name “MOI-BM”, Showa Denko). In addition, these monomers (4) can be used individually by 1 type or in combination of 2 or more types.

  The ratio of the repeating unit derived from the monomer (4) contained in the polymer is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, based on 100 mol% of all repeating units. It is especially preferable that it is 40 mol%.

(Monomer (5))
Specific examples of the monomer (5) include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, glycerol mono Examples thereof include hydroxyalkyl (meth) acrylates such as methacrylate. Of these, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferable. In addition, these monomers (5) can be used individually by 1 type or in combination of 2 or more types.

  The ratio of the repeating unit derived from the monomer (5) contained in the polymer is preferably 5 to 65 mol%, more preferably 10 to 60 mol%, in 100 mol% of all repeating units.

(Monomer (6))
Specific examples of the monomer (6) include acrylic acid, methacrylic acid, crotonic acid, 2-succinoylethyl (meth) acrylate, 2-malenoylethyl (meth) acrylate, 2-hexahydrophthaloylethyl (meta ) Monocarboxylic acids such as acrylate, ω-carboxy-polycaprolactone monoacrylate, monohydroxyethyl phthalate, acrylic acid dimer, 2-hydroxy-3-phenoxypropyl acrylate, t-butoxy methacrylate, t-butyl acrylate; maleic acid And (meth) acrylic acid derivatives having a carboxyl group, including dicarboxylic acids such as fumaric acid, citraconic acid, mesaconic acid and itaconic acid. Of these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloylethyl methacrylate are preferable. In addition, these monomers (6) can be used individually by 1 type or in combination of 2 or more types.

  The ratio of the repeating unit derived from the monomer (6) contained in the polymer is preferably 5 to 65 mol%, more preferably 10 to 60 mol%, in 100 mol% of all repeating units.

  In addition, as a monomer (6), you may use a commercial item. Examples of commercially available products of ω-carboxy-polycaprolactone monoacrylate include trade name “Aronix M-5300” manufactured by Toagosei Co., Ltd. Moreover, as a commercial item of acrylic acid dimer, the Toagosei Co., Ltd. brand name "Aronix M-5600" etc. can be mentioned, for example. Furthermore, as a commercial item of 2-hydroxy-3-phenoxypropyl acrylate, for example, trade name “Aronix M-5700” manufactured by Toagosei Co., Ltd. can be exemplified.

(Monomer (7))
Specific examples of the monomer (7) include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, α-methyl-p-hydroxystyrene, α-methyl-m-hydroxystyrene, α-methyl-o. -Hydroxystyrene, 2-allylphenol, 4-allylphenol, 2-allyl-6-methylphenol, 2-allyl-6-methoxyphenol, 4-allyl-2-methoxyphenol, 4-allyl-2,6-dimethoxy Phenol, 4-allyloxy-2-hydroxybenzophenone, etc. can be mentioned. Of these, p-hydroxystyrene and α-methyl-p-hydroxystyrene are preferable. In addition, these monomers (7) can be used individually by 1 type or in combination of 2 or more types.

  The ratio of the repeating unit derived from the monomer (7) contained in the polymer is preferably 5 to 65 mol%, more preferably 5 to 50 mol%, based on 100 mol% of all repeating units. It is especially preferable that it is 45 mol%.

(Monomer (8))
Specific examples of the monomer (8) include linear or branched methacrylates or acrylates having 1 to 15 carbon atoms. Of these, propyl methacrylate and butyl methacrylate are preferable. These monomers (8) can be used individually by 1 type or in combination of 2 or more types.

  The ratio of the repeating unit derived from the monomer (8) contained in the polymer is preferably 5 to 70 mol%, more preferably 10 to 60 mol%, in 100 mol% of all repeating units.

  The suitable content rate of the repeating unit derived from each of the monomers (3) to (8) contained in the polymer is within the above range. When the content ratio of this repeating unit is lower than the above-mentioned respective preferable content ratios, there are too few reaction sites with the crosslinking component described later, and therefore there is a tendency that the resist pattern is less likely to shrink. On the other hand, if the content ratio of the repeating unit is higher than each of the above-mentioned preferable content ratios, the insolubilized resin composition may swell during development, and the resist pattern may be buried. That is, the line width of the insolubilized resist pattern formed using the insolubilized resin composition when the ratio of the repeating units derived from each of the monomers (3) to (8) contained in the polymer is outside the above range. It may be difficult to control the variation.

(Further other repeating units)
In addition to the above-mentioned repeating unit (1), repeating unit (2), and “other repeating unit” described above, the polymer includes the following in order to control the hydrophilicity and solubility of the insolubilized resin composition: The repeating unit (further other repeating unit) derived from the monomer (9) shown may be included.

(Monomer (9))
Examples of the monomer (9) include (meth) acrylic acid aryl esters, dicarboxylic acid diesters, nitrile group-containing polymerizable compounds, amide bond-containing polymerizable compounds, vinyls, allyls, and chlorine-containing polymerizable compounds. And conjugated diolefins. Specific examples of the monomer (9) include dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; (meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; (meth) acrylic acid esters such as t-butyl (meth) acrylate, 4,4,4-trifluoro-3-hydroxy-3-trifluoromethyl-1-methylbutan-1-yl (meth) acrylate; acrylonitrile, methacrylate Nitrile group-containing polymerizable compounds such as nitrile; Amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; Fatty acid vinyls such as vinyl acetate; Chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; 1,3-butadiene , Isoprene, 1,4-dimethylbutadiene, etc. It can be mentioned diolefins and the like. These monomers (9) can be used individually by 1 type or in combination of 2 or more types.

  Preferable examples of the monomer (9) include a compound represented by the following general formula (4).

In the general formula (4), R ^{7 to} R ⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group, and R ¹⁰ represents Represents a monovalent organic group, R ¹¹ represents a single bond or a divalent organic group having 1 to 20 carbon atoms, and B represents a single bond, an oxygen atom, a carbonyl group, a carbonyloxy group, or an oxycarbonyl. Indicates a group.

In the general formula (4), specific examples of the alkyl group having 1 to 10 carbon atoms represented by R ^{7 to} R ⁹ include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl. Group, octyl group, nonyl group, decyl group and the like. In R ^{7 to} R ⁹ in the general formula (4), it is preferable that R ⁷ and R ⁸ are both hydrogen atoms, and R ⁹ is a hydrogen atom or a methyl group.

R ¹⁰ in the general formula (4) is preferably a monovalent organic group containing a fluorine atom, more preferably a fluoroalkyl group having 1 to 20 carbon atoms, and fluoro having 1 to 4 carbon atoms. Particularly preferred is an alkyl group. Specific examples of the “fluoroalkyl group having 1 to 20 carbon atoms” include difluoromethyl group, perfluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2- Trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (tri Fluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl Group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoromethyl) -2,2,2-trifluoroethyl group, 2 (Perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,4 5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodeca Fluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, 2- (perfluoropentyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodeca Fluoroheptyl group, perfluorohexylmethyl group, perful Loheptyl group, 2- (perfluorohexyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6,7,7-tetradecafluorooctyl group, perfluoroheptyl Methyl group, perfluorooctyl group, 2- (perfluoroheptyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8- Hexadecafluorononyl group, perfluorooctylmethyl group, perfluorononyl group, 2- (perfluorooctyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6 , 7, 7, 8, 8, 9, 9-octadecafluorodecyl group, perfluorononylmethyl group, perfluorodecyl group, and the like.

  If the fluoroalkyl group has too many carbon atoms, the solubility in an aqueous alkali solution tends to be low, and thus it may be difficult to remove the unreacted insolubilized resin composition with a developer after thermosetting. For this reason, among the specific examples of the “fluoroalkyl group having 1 to 20 carbon atoms”, a perfluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group are preferable.

In the general formula (4), specific examples of the divalent organic group having 1 to 20 carbon atoms represented by R ¹¹ include a methylene group, an ethylene group, a 1,3-propylene group, and a 1,2-propylene group. , Tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group Hexadecamethylene group, heptacamethylene group, octadecamethylene group, nonadecamethylene group, insalene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl- 1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, ethylidene group Saturated chain hydrocarbon groups such as 1-propylidene group and 2-propylidene group; cyclobutylene groups such as 1,3-cyclobutylene group, cyclopentylene groups such as 1,3-cyclopentylene group, 1,4 A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms, including a cyclohexylene group such as a cyclohexylene group and a cyclooctylene group such as a 1,5-cyclooctylene group; 4 to 4 cyclic carbon atoms, including 4-norbornylene group, norbornylene group such as 2,5-norbornylene group, adamantylene group such as 1,5-adamantylene group, 2,6-adamantylene group, etc. Examples thereof include bridged cyclic hydrocarbon ring groups such as 20 hydrocarbon ring groups.

  Preferable examples of the compound represented by the general formula (4) (monomer (9)) include 2-((trifluoromethyl) sulfonylamino) ethyl methacrylate, 2-((trifluoromethyl) sulfonylamino) Examples include ethyl acrylate and compounds represented by the following formulas (4-1) to (4-6).

  The ratio of “another repeating unit” contained in the polymer is preferably 1 to 50 mol%, more preferably 2 to 30 mol%, and more preferably 2 to 20 mol% in 100 mol% of all repeating units. It is particularly preferred.

(Polymer preparation method)
The polymer uses, for example, a monomer component, a radical polymerization initiator such as hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, etc., if necessary, in the presence of a chain transfer agent, It can be prepared by polymerization in a suitable solvent.

  Examples of the solvent used for polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, norbornane. Cycloalkanes such as benzene, toluene, xylene, ethylbenzene, cumene and other aromatic hydrocarbons; chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide, chlorobenzene and other halogenated hydrocarbons; ethyl acetate, acetic acid n- Saturated carboxylic acid esters such as butyl, i-butyl acetate, methyl propionate and propylene glycol monomethyl ether acetate; alkyl lactones such as γ-butyrolactone; ethers such as tetrahydrofuran, dimethoxyethane and diethoxyethane; 2 Alkyl ketones such as butanone, 2-heptanone and methyl isobutyl ketone; cycloalkyl ketones such as cyclohexanone; alcohols such as 2-propanol, 1-butanol, 4-methyl-2-pentanol and propylene glycol monomethyl ether Can be mentioned. These solvents can be used alone or in combination of two or more.

  The temperature of the polymerization reaction is usually 40 to 120 ° C, and preferably 50 to 100 ° C. The polymerization reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

  The polymer has a high purity, that is, a low content of impurities such as halogen and metal, and the residual monomer component and oligomer component are below a predetermined value (for example, 0 by analysis by HPLC). .1% by mass or less). By using an insolubilized resin composition containing a polymer having a high purity, the process stability is improved and the resist pattern shape can be further refined.

  As a method for removing impurities such as metals from the polymer, (1) a method in which the metal in the polymerization solution is adsorbed using a zeta potential filter, and (2) the polymerization solution is washed with an acidic aqueous solution such as oxalic acid or sulfonic acid. By doing so, a method of removing the metal in a chelated state can be exemplified. Moreover, as a method of making the monomer component and oligomer component which remain | survive in a polymer into below a regulation value, (3) Liquid which removes the monomer component and oligomer component which remain | survives by combining water washing and a suitable solvent -Liquid extraction method, (4) Purification method in a solution state such as ultrafiltration that extracts and removes only components having a specific molecular weight or less, (5) The polymer is added to the poor solvent by dropping the polymerization solution into the poor solvent. And a reprecipitation method in which the remaining monomer components are removed, and (6) a purification method in a solid state such as washing the filtered polymer with a slurry poor solvent. In addition, you may perform these methods combining 2 or more.

(Physical properties of polymer)
The polystyrene-reduced mass average molecular weight (hereinafter also referred to as “Mw”) of the polymer measured by gel permeation chromatography (GPC) is usually 1,000 to 500,000, and 1,000 to 50,000. It is preferable that it is, and it is still more preferable that it is 1,000-20,000. If the Mw of the polymer is more than 500,000, it tends to be difficult to remove the unreacted insolubilized resin composition with a developer after thermosetting. On the other hand, when the Mw of the polymer is less than 1,000, it tends to be difficult to form a uniform coating film after coating.

(solvent)
The solvent contained in the insolubilized resin composition of the present invention can sufficiently dissolve the polymer contained in the insolubilized resin composition at the same time, and components such as crosslinking components and surfactants contained as necessary. If it is, it will not be restrict | limited. However, it is preferable that the solvent is difficult to dissolve the first resist pattern. Specific examples of such solvents include alcohol solvents, ether solvents, ketone solvents, ester solvents, water and the like. Of these, alcohol solvents are particularly preferable.

(Alcohol solvent)
The “alcohol solvent” may be a solvent containing only an alcohol or a solvent containing a small amount of a solvent other than an alcohol. As alcohol, C1-C8 monohydric alcohol is preferable. Specific examples of the alcohol include 1-propanol, isopropyl alcohol, 1-butanol, 2-butanol, t-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl- 3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, Examples include 1-heptanol, 2-heptanol, 2-methyl-2-heptanol, 2-methyl-3-heptanol and the like. Kill. Of these, 1-butanol, 2-butanol, and 4-methyl-2-pentanol are preferable. These alcohols can be used singly or in combination of two or more.

  The water content of the alcohol solvent is preferably 10% by mass or less, more preferably 3% by mass or less. When the water content of the alcohol solvent exceeds 10% by mass, the solubility of the polymer tends to decrease. The alcohol solvent is particularly preferably a non-aqueous solvent containing alcohol (an anhydrous alcohol solvent substantially free of water).

  In the case where an alcohol solvent is used as the solvent, the proportion of the alcohol solvent contained in the insolubilized resin composition is preferably 80% by mass or more, assuming that the entire insolubilized resin composition is 100% by mass, More preferably, it is at least mass%. When the content of the alcohol solvent is less than 80% by mass, components such as a polymer, a crosslinking component, and a surfactant tend not to be sufficiently dissolved. In addition, although it does not specifically limit about the upper limit of the content rate of alcohol solvent, It is preferable to set it as 99 mass% or less.

(Ether solvent)
The “ether solvent” may contain a trace amount of a solvent other than ether, in addition to a solvent containing only ether. Specific examples of ethers include cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl Examples thereof include alkyl ethers of polyhydric alcohols such as ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. These ethers can be used singly or in combination of two or more.

(Ketone solvent)
The “ketone solvent” may be a solvent containing only a ketone, or may contain a trace amount of a solvent other than a ketone. Specific examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol and the like.

(Ester solvent)
The “ester solvent” may be a solvent containing only an ester, or a solvent containing a small amount of a solvent other than an ester. Specific examples of the ester include ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, Examples include methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl acetate, butyl acetate and the like.

  In the case of using the above-mentioned alcohol solvent as the solvent, this alcohol solvent includes “other solvents” other than alcohol in order to adjust the coating property when coating on the first resist pattern. It may be. Specific examples of “other solvents” include the above-mentioned ether solvents, ketone solvents, ester solvents, and water, as well as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol monomethyl. Examples include alkyl ether acetates of polyhydric alcohols such as ether acetate; aromatic hydrocarbons such as toluene and xylene. Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, esters, and water are preferred.

  In the case where the “other solvent” is contained in the alcohol solvent, the ratio of the “other solvent” contained in the alcohol solvent is usually 30% by mass or less, assuming that the entire alcohol solvent is 100% by mass. Preferably it is 20 mass% or less. If the content ratio of “other solvent” is more than 30% by mass, the first resist pattern may be eroded, causing problems such as intermixing with the insolubilized resin composition. The first resist pattern may be filled. When the “other solvent” is water, the water content is preferably 10% by mass or less.

(Crosslinking component)
The insolubilized resin composition of the present invention may contain a crosslinking component as an optional component. A crosslinking component is a component which shows the effect | action which reacts with a polymer by the effect | action of an acid, or a crosslinking component, and hardens a polymer.

  The crosslinking component includes a compound having a group represented by the following general formula (5) (hereinafter also referred to as “crosslinking component (1)”) or a compound having two or more cyclic ethers as a reactive group (hereinafter referred to as “reactive group”). , Also referred to as “crosslinking component (2)”. In addition, it is also preferable that a crosslinking component contains both a crosslinking component (1) and a crosslinking component (2).

In the general formula (5), R ¹² and R ¹³ each independently represent a hydrogen atom or a group represented by the following general formula (6). However, at least one of R ¹² and R ¹³ is a group represented by the following general formula (6).

In the general formula (6), R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having 1 to 6 carbon atoms, or R ¹⁴ and R ¹⁵ represents a ring having 2 to 10 carbon atoms formed by bonding to each other. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

(Crosslinking component (1))
Examples of the crosslinking component (1) include compounds having a functional group such as an imino group, a methylol group, or a methoxymethyl group in the molecule. Specific examples of the crosslinking component (1) include all or part of active methylol groups such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, and (poly) methylolated urea. Examples thereof include nitrogen-containing compounds which are alkylated into alkyl ethers.

  Specific examples of the “alkyl group” when alkylating all or part of the active methylol group include a methyl group, an ethyl group, a butyl group, or a group obtained by mixing these.

  Further, the nitrogen-containing compound may contain an oligomer component partially self-condensed. Specific examples of such nitrogen-containing compounds include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril and the like.

As the commercially available crosslinking component (1), the following trade names are as follows: Cymel 300, 301, 303, 350, 232, 235, 236, 238, 266, 267, 285. 1123, 1123-10, 1170, 370, 771, 272, 1172, 325, 327, 703, 712, 254, 253, 212, 1128, 701 202, 207 (manufactured by Nippon Cytec Co., Ltd.), Nicarak MW-30M, 30, 22, 24X, Nicarak MS-21, 11, 001, Nicarax MX-002, 730, 750 708, 706, 042, 035, 45, 410, 302, 202, Nicarak SM-651, 652, 653, 551, 45 , Nikaluck SB-401, 355, 303, 301, 255, 203, 201, Nicalack BX-4000, 37, 55H, Nicalack BL-60 (above, Sanwa Chemical Co., Ltd.), Aaron Oxetane OXT-101, 121, 221 (from Toagosei Co., Ltd.), OXTP, OXBP (from Ube Industries, Ltd.), and the like. Among them, Cymel 325, 327, 703, 712, 254, 253, 212, 1128, which corresponds to the compound in which R ¹² or R ¹³ is a hydrogen atom in the general formula (5), 701, 202 and 207 are preferable. These crosslinking components (1) can be used singly or in combination of two or more.

(Crosslinking component (2))
Specific examples of the crosslinking component (2) include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4- Epoxy) cyclohexane-m-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4'-epoxy-6'-methylcyclohexanecarboxylate, methylene bis (3,4-epoxycyclohexane), di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylene bis (3,4-epoxycyclohexanecarboxylate) .Epsilon.-caprolactone modified 3,4- Epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3,4- An epoxycyclohexyl group-containing compound such as epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate;

Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, Hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol Diglycidyl ether, polypropylene glycol Diglycidyl ether and other ethylene glycol, propylene group Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as coal and glycerin; diglycidyl esters of aliphatic long-chain dibasic acids; Glycidyl ethers; monoglycidyl ethers of polyether alcohols; glycidyl esters of higher fatty acids;

3,7-bis (3-oxetanyl) -5-oxanonane, 3,3 ′-(1,3- (2-methylenyl) propanediylbis (oxymethylene)) bis- (3-ethyloxetane), 1,4 -Bis ((3-ethyl-3-oxetanylmethoxy) methyl) benzene, 1,2-bis ((3-ethyl-3-oxetanylmethoxy) methyl) ethane, 1,3-bis ((3-ethyl-3- Oxetanylmethoxy) methyl) propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyl bis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis (3-ethyl-3-oxetanyl) Methyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, Cyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, dipe Taerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ) Ether, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether, ethylene oxide (EO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, propylene oxide (PO) modified bisphenol A bis (3 -Ethyl-3-oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-e Til-3-oxetanylmethyl) ether, EO-modified bisphenol F (3-ethyl-3-oxetanylmethyl) ether, and the like.

  In addition, as the commercially available crosslinking component (2), Aron Oxetane OXT-101, 121, 221 (above, manufactured by Toagosei Co., Ltd.), OXTP, OXBP, OXIPA (above, Ube Industries) For example). These commercial products are oxetane compounds having two or more oxetane rings in each molecule.

  Among the crosslinking components (2) described above, 1,6-hexanediol diglycidyl ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, and OXIPA are preferable. These crosslinking components (2) can be used singly or in combination of two or more.

(Surfactant)
The insolubilized resin composition of the present invention may contain a surfactant as an optional component. The inclusion of a surfactant is preferable because the coating property, antifoaming property, leveling property and the like of the insolubilized resin composition are improved.

  Specific examples of the surfactant are BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (and above, Dainippon Ink Chemical, Inc.) under the trade names below. Manufactured by Kogyo Co., Ltd.), FLORARD FC-135, FC-170C, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S -141, S-145 (above, manufactured by Asahi Glass), SH-28PA, -190, -193, SZ-6032, SF-8428 (above, manufactured by Toray Dow Corning Silicone), etc. An agent can be mentioned.

  When the surfactant is contained in the insolubilized resin composition, the content of the surfactant is preferably 5 parts by mass or less with respect to 100 parts by mass of the polymer.

2. Resist pattern formation method:
(Process (1))
In the step (1), for example, spin coating, casting coating, roll coating, etc. on a first resist pattern formed on a substrate such as a silicon wafer, a wafer coated with SiN or an organic antireflection film, or the like. The insolubilized resin composition is applied by appropriate application means. At this time, the insolubilized resin composition is applied so that the first resist pattern is covered.

  The method for forming the first resist pattern on the substrate is not particularly limited, and may be formed according to a general resist pattern forming method. Specifically, the first resist pattern is formed by the following method. Can do. First, a radiation-sensitive resin composition (hereinafter also referred to as “resist agent”) to be described later is applied onto a substrate by an appropriate application means such as spin coating, cast coating, roll coating or the like. Thereby, the 1st resist layer which consists of a resist agent can be formed. In addition, after apply | coating a resist agent, you may volatilize the solvent in a coating film by prebaking (PB) as needed. Although the prebaking heating conditions are appropriately selected depending on the composition of the resist agent, it is usually 30 to 200 ° C. for 30 to 120 seconds, and preferably 50 to 150 ° C. for 40 to 100 seconds.

  In order to maximize the potential of the resist agent, an organic or inorganic antireflection film is formed on the substrate as disclosed in, for example, Japanese Patent Publication No. 6-12458. Is preferred. In order to prevent the influence of basic impurities contained in the environmental atmosphere, it is also preferable to provide a protective film on the first resist layer as disclosed in, for example, JP-A-5-188598. . It is also preferable to perform both formation of the antireflection film and formation of the protective film.

  The formed first resist layer is selectively exposed, for example, by irradiating with radiation through a mask having a predetermined pattern to form a pattern latent image portion (portion that has become insoluble in alkali by exposure). The radiation used is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, etc., depending on the type of acid generator contained in the resist agent, but an ArF excimer laser (wavelength 193 nm). ) And KrF excimer laser (wavelength 248 nm) are preferred, and ArF excimer laser (wavelength 193 nm) is particularly preferred. The exposure conditions such as the exposure amount are appropriately selected according to the compounding composition of the resist agent and the type of additive. Furthermore, in this invention, it is preferable to perform heat processing (PEB) after exposure. By this PEB, the dissociation reaction of the acid dissociable group in the resin component can be smoothly advanced. The heating conditions for PEB are appropriately selected depending on the composition of the resin composition, but are usually 30 to 200 ° C. for 30 to 120 seconds, and preferably 50 to 170 ° C. for 40 to 100 seconds.

By developing the exposed first resist layer, the pattern latent image portion is exposed, and a positive first resist pattern having a predetermined line width L ₁ and having a predetermined space portion as shown in FIG. 1 is formed on the substrate 10. Examples of the developer that can be used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, the non-exposed portion tends to be easily dissolved in the developer. In addition, after developing using alkaline aqueous solution, generally it wash | cleans with water and dries.

  An organic solvent can also be added to the alkaline aqueous solution (developer). Examples of the organic solvent that can be added include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol , N-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol, and the like; tetrahydrofuran, dioxane Ethers such as ethyl acetate, n-butyl acetate, i-amyl acetate, aromatic hydrocarbons such as toluene and xylene, phenol, acetonylacetone, dimethylformamide, etc. That. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

  The addition amount of the organic solvent is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. When the addition amount of the organic solvent is more than 100 parts by volume with respect to 100 parts by volume of the alkaline aqueous solution, the developability may be deteriorated and the development residue in the exposed part may increase. An appropriate amount of a surfactant or the like can be added to the developer.

The insolubilized resin composition is applied onto the first resist pattern formed on the substrate, and is heated (baked) or UV cured, and then washed. By this heat treatment or UV curing, the first resist pattern is reacted with the applied insolubilized resin composition. Although heating conditions are suitably selected by the compounding composition of an insolubilized resin composition, it is 30-200 degreeC normally, and it is preferable that it is 50-170 degreeC. On the other hand, for UV curing, lamps such as Ar ₂ lamp, KrCl lamp, Kr ₂ lamp, XeCl lamp, Xe ₂ lamp (USHIO Inc.) can be used.

  If the development is carried out in the same manner as when the first resist pattern is formed after cooling appropriately, an insoluble film in which the surface of the first resist pattern 1 is made of an insolubilized resin composition as shown in FIGS. 5, an insolubilized resist pattern 3 that is a line-and-space pattern having a first line portion 1 a and a first space portion 1 b can be formed. The insoluble film 5 is insoluble or hardly soluble in the developer and a resist agent described later. Therefore, the insolubilized resist pattern 3 (first line portion 1a) covered with the insoluble film 5 is insoluble or hardly soluble in the resist agent. After development, the insolubilized resist pattern may be cured a plurality of times by heat treatment (PEB) or UV curing as necessary.

  The insolubilized first resist pattern 1 (insolubilized resist pattern 3) remains in the pattern shape even if the resist agent is applied, exposed and developed in the following steps (2) and (3). However, the pattern width may slightly change depending on the thickness of the applied insolubilized resin composition. In addition, you may perform this process (1) in multiple times as needed.

(Process (2))
In step (2), as shown in FIG. 4, a resist agent described later is applied onto the insolubilized resist pattern 3 formed on the substrate 10 by an appropriate application means such as spin coating, cast coating, roll coating or the like. Then, the second resist layer 12 made of a resist agent is formed. Then, you may pre-bake (PB) as needed. Next, as in the case of forming the first resist pattern, the second resist layer 12 and, if necessary, the space portion of the first resist pattern (insolubilized resist pattern 3) are selectively selected via a mask. Exposure. Note that heat treatment (PEB) may be further performed as necessary.

(Process (3))
In the step (3), a positive second resist pattern is formed by development. Through the above steps, a resist pattern having a configuration in which a first resist pattern (insolubilized resist pattern) and a second resist pattern are sequentially added on the substrate can be formed. If the resist pattern formed in this way is used, a semiconductor can be manufactured.

  In the above-described step (2), various resist patterns having a characteristic pattern arrangement can be finally formed by appropriately selecting a mask pattern used for selective exposure. For example, as shown in FIG. 5, when the insolubilized resist pattern 3 having the first line portion 1a and the first space portion 1b is formed, the mask pattern used in the exposure in the step (2) is selected to select the second pattern. The second line portion 2a of the second resist pattern 2 having the line portion 2a and the second space portion 2b can be formed in the first space portion 1b in parallel with the first line portion 1a.

  For example, as shown in FIG. 6, the second line of the second resist pattern 22 having the second line portion 22a and the second space portion 22b is selected by selecting a mask pattern used in the exposure in the step (2). If the portion 22a is formed in a grid pattern in the first space portion 1b, a resist pattern (contact hole pattern) having the contact hole 15 defined by the first line portion 1a and the second line portion 22a of the insolubilized resist pattern is formed. be able to.

  Further, for example, as shown in FIGS. 7 and 8, if the mask pattern used in the exposure in the step (2) is selected, the second resist pattern 32 having the second line portion 32a and the second space portion 32b is selected. The two line portions 32a can be formed on the first line portion 1a so as to intersect the first line portion 1a.

(Radiation sensitive resin composition)
The “radiation-sensitive resin composition (resist agent)” used in the resist pattern forming method of the present invention has an acid dissociable group dissociated by the action of an acid generated from an acid generator by exposure, The exposed portion of the resist having increased solubility in an alkali developer is dissolved and removed by the alkali developer, and a positive resist pattern can be obtained.

  In this specification, for the sake of convenience, the resist agent used for forming the first resist pattern is referred to as “first resist agent”, and the resist agent used for forming the second resist pattern is referred to as “second resist agent”. " Both the first resist agent and the second resist agent usually contain a resin having an acid dissociable group. Furthermore, as other components, a radiation-sensitive acid generator (hereinafter also referred to as “acid generator”) and a solvent are usually contained. Hereinafter, the details of the resist agent (second resist agent) used in the step (2) will be described, but the details of the first resist agent are the same, and the first resist agent and the second resist agent are the same. It may or may not be different. Hereinafter, the term “resist agent” means both “first resist agent” and “second resist agent”.

(Resin having an acid dissociable group)
The resin having an acid dissociable group is preferably a resin containing one or more repeating units represented by the following general formula (7).

In the general formula (7), R ¹⁷ represents hydrogen or a methyl group, and a plurality of R ¹⁸ are independently (i) a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or A derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms (provided that at least one of R ¹⁸ is a monovalent polycyclic hydrocarbon group having 7 to 20 carbon atoms or a derivative thereof) Or (ii) a divalent polycyclic hydrocarbon group having 4 to 20 carbon atoms, each of which is formed by bonding any two of R ¹⁸ to each other, each containing a bonded carbon atom, or The remaining R ¹⁸ represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof.

In the general formula (7), a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ¹⁸ and any two R ¹⁸ bonded to each other are used to form 4 to 4 carbon atoms. Specific examples of the 20 divalent alicyclic hydrocarbon groups are derived from cycloalkanes such as norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, and the like. A group consisting of an alicyclic ring; a group consisting of these alicyclic rings is, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1- Examples include a group substituted with one or more linear, branched, or cyclic alkyl groups having 1 to 4 carbon atoms such as a methylpropyl group and a t-butyl group. Of these, a group composed of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane and cyclohexane, and a group obtained by substituting these with the above alkyl group are preferable.

In the general formula (7), specific examples of the derivative of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ¹⁸ include a hydroxyl group; a carboxyl group; an oxo group (that is, ═O Group); hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3 A hydroxyalkyl group having 1 to 4 carbon atoms such as -hydroxybutyl group and 4-hydroxybutyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1 -C1-C4 alkoxyl groups such as methylpropoxy group and t-butoxy group; cyano group; cyanomethyl group, 2-cyanoethyl group, 3-cyano The group which has 1 or more types of substituents, such as C2-C5 cyanoalkyl groups, such as a propyl group and 4-cyanobutyl group, can be mentioned. Of these, a group having a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, or a cyanomethyl group is preferable.

In the general formula (7), specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ¹⁸ include a methyl group, an ethyl group, an n-propyl group, i- A propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned. Of these, a methyl group and an ethyl group are preferable.

In the general formula (7), specific examples of the group represented by “—C (R ¹⁸ ) ₃ ” include groups represented by the following general formulas (7a) to (7e) and the following formula (7f). The group represented by these can be mentioned.

In the general formulas (7a) to (7e), R ¹⁹ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, and m is 0 or 1.

  Specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1- Examples thereof include a methylpropyl group and a t-butyl group. Of these, a methyl group and an ethyl group are preferable.

In the general formula (7), the portion represented by “—COOC (R ¹⁸ ) ₃ ” is a portion that is dissociated by the action of an acid to form a carboxyl group and becomes an alkali-soluble portion. This “alkali-soluble site” is a group that becomes an anion (alkali-soluble) by the action of an alkali. On the other hand, an “acid-dissociable group” is a group in which an alkali-soluble site is protected with a protecting group, and is a group that is not “alkali-soluble” until the protecting group is removed with an acid.

  The resin having an acid-dissociable group is a resin that is itself insoluble in alkali or hardly soluble in alkali, but becomes alkali-soluble by the action of an acid. Here, “alkali insoluble or hardly alkali soluble” means development conditions for forming a resist pattern using a resist layer comprising a resist agent containing a resin having a repeating unit represented by the general formula (7). Thus, when a film made of only the resin containing the repeating unit represented by the general formula (7) is processed (but not exposed), 50% or more of the initial film thickness of the film remains after the processing. Refers to nature. On the other hand, “alkali-soluble” refers to a property in which 50% or more of the initial film thickness of the film is lost after the same treatment.

(Method for preparing resin having acid-dissociable group)
Resins having an acid-dissociable group include monomer components containing a polymerizable unsaturated monomer corresponding to a desired repeating unit, hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, etc. Can be prepared by polymerization in a suitable solvent in the presence of a chain transfer agent, if necessary.

  Examples of the solvent used for polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, norbornane. Cycloalkanes such as benzene, toluene, xylene, ethylbenzene, cumene and other aromatic hydrocarbons; chlorobutanes, bromohexanes, dichloroethanes, halogenated hydrocarbons such as hexamethylene dibromide, chlorobenzene; ethyl acetate, Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ethers such as tetrahydrofuran, dimethoxyethanes and diethoxyethane; methanol, ethanol, 1-propanol, 2-propanol, 1- Butanol, 2-pig Alcohol, isobutanol, 1-pentanol, 3-pentanol, 4-methyl-2-pentanol, o-chlorophenol, 2- (1-methylpropyl) phenol, etc .; acetone, 2-butanone, Mention may be made of ketones such as 3-methyl-2-butanone, 4-methyl-2-pentanone, 2-heptanone, cyclopentanone, cyclohexanone and methylcyclohexanone. These solvents can be used alone or in combination of two or more.

  Moreover, the reaction temperature in said superposition | polymerization is 40-150 degreeC normally, it is preferable that it is 50-120 degreeC, and reaction time is 1-4 hours normally, and it is preferable that it is 1-24 hours.

  A resin having an acid-dissociable group is more preferable as the content of impurities such as halogen and metal is smaller because sensitivity, resolution, process stability, pattern profile, and the like can be improved. Examples of the purification method of the resin having an acid dissociable group include chemical purification methods such as washing with water and liquid-liquid extraction, and these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. A combined method and the like can be given.

  It is preferable that the ratio of the low molecular weight component which has a monomer as a main component contained in resin which has an acid dissociable group is 0.1 mass% or less in conversion of solid content with respect to the whole resin. The content ratio of the low molecular weight component can be measured, for example, by high performance liquid chromatography (HPLC).

(Physical property value of resin having acid dissociable group)
The polystyrene-reduced mass average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the resin having an acid dissociable group is usually 1,000 to 500,000, and 1,000 to 100,000. It is preferable that it is 1,000-50,000. When Mw is less than 1,000, the heat resistance of the resist pattern to be formed tends to decrease. On the other hand, if the Mw exceeds 500,000, the developability tends to be lowered. Further, the ratio (Mw / Mn) of Mw of the resin having an acid dissociable group and the polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is preferably 1 to 5, More preferably, it is 1-3.

(Acid generator)
The resist agent preferably contains an acid generator that has a structure represented by the following general formula (8) and is decomposed by exposure. By containing an acid generator in the resist agent, an acid is generated by exposure, the acid-dissociable group is dissociated, the exposed region of the resist layer becomes alkali-soluble, and a resist pattern can be formed.

In the general formula (8), R ²⁰ represents a linear or branched alkyl group or alkoxyl group having 1 to 10 carbon atoms, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. Indicates a group. R ²¹ represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or 2 carbon atoms. -11 linear or branched alkoxycarbonyl group is shown.

In the general formula (8), R ^{22 s} may be independently of each other a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group, or a substituted group. It may be a good naphthyl group, or two R ^22s may be bonded to each other to form a divalent group having 2 to 10 carbon atoms. In addition, the formed bivalent group may be substituted. k is an integer of 0 to 2, and X ⁻ is a general formula: R ²³ C _n F _2n SO ₃ ⁻ (wherein R ²³ is a fluorine atom or an optionally substituted carbon atom having 1 to 12 carbon atoms. An anion represented by a hydrogen group, n is an integer of 1 to 10), and q is an integer of 0 to 10 (preferably an integer of 0 to 2).

In the general formula (8), examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ²⁰ , R ²¹ , and R ²² include a methyl group, an ethyl group, and an n-propyl group. I-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group , 2-ethylhexyl group, n-nonyl group, n-decyl group and the like. Of these, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

In the general formula (8), examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms represented by R ²⁰ and R ²² include a methoxy group, an ethoxy group, an n-propoxy group, and an i-propoxy group. Group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyl An oxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group, etc. can be mentioned. Of these, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group and the like are preferable.

In the general formula (8), examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms represented by R ²¹ include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, i- Propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, Examples include n-heptyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like. Of these, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

In the general formula (8), examples of the linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms represented by R ²⁰ include a methanesulfonyl group, an ethanesulfonyl group, and an n-propanesulfonyl group. N-butanesulfonyl group, t-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group, n -Nonanesulfonyl group, n-decanesulfonyl group, cyclopentanesulfonyl group, cyclohexanesulfonyl group, etc. can be mentioned. Of these, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable. Moreover, q is preferably 0-2.

In the general formula (8), examples of the optionally substituted phenyl group represented by R ²² include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, and 2,3-dimethylphenyl. Group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl Group, 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group and the like; linear, branched or cyclic alkyl having 1 to 10 carbon atoms A phenyl group substituted by a group; these phenyl group or alkyl-substituted phenyl group can be converted into a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxy group; Examples include a group substituted with at least one group such as an alkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Examples of the alkoxyl group among the substituents for the phenyl group and the alkyl-substituted phenyl group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, 1 -A linear, branched or cyclic alkoxyl group having 1 to 20 carbon atoms such as a methylpropoxy group, a t-butoxy group, a cyclopentyloxy group and a cyclohexyloxy group.

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

Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, A linear, branched, or cyclic alkoxycarbonyloxy group having 2 to 21 carbon atoms such as cyclopentyloxycarbonyl group and cyclohexyloxycarbonyl can be exemplified. In the general formula (8), the optionally substituted phenyl group represented by R ²² includes a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, a 4-t -A butoxyphenyl group and the like are preferable.

In the general formula (8), examples of the optionally substituted naphthyl group represented by R ²² include 1-naphthyl group, 2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 4 -Methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 6-methyl-1-naphthyl group, 7-methyl-1-naphthyl group, 8-methyl-1- Naphthyl group, 2,3-dimethyl-1-naphthyl group, 2,4-dimethyl-1-naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6-dimethyl-1-naphthyl group, 2,7 -Dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4-dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl group, 3,6-dimethyl-1-naphthyl Group, 3,7-dimethyl-1-naphthyl group, 3 , 8-dimethyl-1-naphthyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group, 2-naphthyl group, 1-methyl- A naphthyl group such as a 2-naphthyl group, a 3-methyl-2-naphthyl group, and a 4-methyl-2-naphthyl group; a naphthyl substituted with a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms Group; one or more of these naphthyl groups or alkyl-substituted naphthyl groups are substituted with at least one group such as hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, alkoxycarbonyloxy group, etc. And the like. Specific examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, and alkoxycarbonyloxy group among these substituents include the groups exemplified for the aforementioned phenyl group and alkyl-substituted phenyl group.

In the general formula (8), the optionally substituted naphthyl group represented by R ²² includes a 1-naphthyl group, a 1- (4-methoxynaphthyl) group, a 1- (4-ethoxynaphthyl) group, 1 -(4-n-propoxynaphthyl) group, 1- (4-n-butoxynaphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n- And propoxynaphthyl) group and 2- (7-n-butoxynaphthyl) group.

In the general formula (8), the divalent group having 2 to 10 carbon atoms formed by bonding two R ²² to each other is a 5-membered or 6-membered group together with the sulfur atom in the general formula (8). Groups that form a ring, preferably a 5-membered ring (ie, a tetrahydrothiophene ring) are desirable. Examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. Group, alkoxycarbonyloxy group and the like. Incidentally, as the R ²² in the general formula (8), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, 1-naphthyl group, tetrahydrothiophene two R ²² are taken together with the attached to a sulfur atom each other to form a ring structure A divalent group or the like that forms is preferable.

  As the cation moiety in the general formula (8), triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-t-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, di-4-fluorophenyl- Phenylsulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl-diphenylsulfonium cation, 4-methanesulfonylphenyl-diphenylsulfonium cation, 4-cyclohexanesulfonyl-diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation, 1- Naphthyldiethylsulfonium cation, 1- (4-hydroxynaphthyl) dimethylsulfonium cation, 1- (4-methyl) Naphthyl) dimethylsulfonium cation, 1- (4-methylnaphthyl) diethylsulfonium cation, 1- (4-cyanonaphthyl) dimethylsulfonium cation, 1- (4-cyanonaphthyl) diethylsulfonium cation, 1- (3,5-dimethyl -4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthyl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthyl) Tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation, 2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthyl) tetrahydrothi Fe cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) can be exemplified tetrahydrothiophenium cation, or the like.

In the general formula (8), the “—C _n F _2n —” group in the anion represented by X ⁻ (general formula: R ²³ C _n F _2n SO ₃ ⁻ ) is a perfluoroalkylene group having n carbon atoms. However, the perfluoroalkylene group may be linear or branched. Note that n is preferably 1, 2, 4, or 8.

The optionally substituted good C1-12 hydrocarbon group represented by R ^23, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a bridged alicyclic hydrocarbon group. Specific examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group. N-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl group Etc.

  Preferable examples of preferred anion sites in the general formula (8) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hepta. -2-yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, and the like.

  The acid generator having the structure represented by the general formula (8) can be used alone or in combination of two or more.

(Other acid generators)
As the resist agent, “other acid generators” other than the acid generators described above can be used. Examples of “other acid generators” include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, and the like.

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

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

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

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

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

  Among these “other acid generators”, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta. 2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, Bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2, 2-te Lafluoroethanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, trifluoromethanesulfonylbicyclo [2.2.1] Hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2 2.1] hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfur Nilbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro- n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid Imidotrifluoromethanesulfonate and the like are preferable. These “other acid generators” can be used singly or in combination of two or more.

  It is also preferable to use together the acid generator having the structure represented by the general formula (8) and “other acid generator”. When “other acid generator” is used in combination, the ratio of “other acid generator” used is the sum of the acid generator having the structure represented by the general formula (8) and “other acid generator”. Is usually 80% by mass or less, preferably 60% by mass or less.

(solvent)
The resist agent is preferably prepared by dissolving various components including a resin having an acid dissociable group in a solvent.

  The solvent is preferably at least one selected from the group consisting of propylene glycol monomethyl ether acetate, 2-heptanone, and cyclohexanone (hereinafter also referred to as “solvent (1)”).

  Further, a solvent other than the solvent (1) (hereinafter, also referred to as “other solvent”) can be used alone or mixed with the solvent (1).

  Specific examples of other solvents include propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl ether acetate, propylene glycol mono-i -Propylene glycol monoalkyl ether acetates such as butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3-dimethyl-2-butanone, 2-octanone, etc. Branched ketones;

Cyclic ketones such as cyclopentanone, 3-methylcyclopentanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-hydroxypropionic acid n-propyl, i-propyl 2-hydroxypropionate, n-butyl 2-hydroxypropionate, i-butyl 2-hydroxypropionate, sec-butyl 2-hydroxypropionate, t-butyl 2-hydroxypropionate, etc. Alkyl 2-hydroxypropionates; in addition to alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate,

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

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

  When the solvent (1) and another solvent are used in combination as the solvent, the proportion of the other solvent is usually 50% by mass or less, preferably 30% by mass or less, and preferably 25% by mass with respect to the total solvent. % Or less is more preferable.

  The amount of the solvent contained in the resist agent is such that the total solid content contained in the resist agent is usually 2 to 70% by mass, and preferably 4 to 25% by mass, The amount is more preferably 4 to 10% by mass.

  The resist agent is prepared by dissolving each component in a solvent so that the total solid content concentration is in the above-described numerical range to obtain a uniform solution, and then filtering with a filter having a pore size of about 0.02 μm, for example. be able to.

(Acid diffusion control agent)
The resist agent preferably contains an acid diffusion control agent. The acid diffusion control agent is a component having an action of controlling a diffusion phenomenon of an acid generated from an acid generator by exposure in a resist layer and suppressing an undesirable chemical reaction in a non-exposed region. By blending such an acid diffusion control agent, the storage stability of the resist agent is improved, the resolution of the resist is further improved, and due to fluctuations in the holding time (PED) from exposure to heat treatment after exposure. A change in the line width of the resist pattern can be suppressed, and a composition having extremely excellent process stability can be obtained. As the acid diffusion controller, it is preferable to use a nitrogen-containing organic compound or a photodisintegratable base.

(Nitrogen-containing organic compounds)
Examples of the nitrogen-containing organic compound include a compound represented by the following general formula (10) (hereinafter, also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter, “ Nitrogen-containing compound (II) ”, polyamino compounds having three or more nitrogen atoms in the same molecule and polymers thereof (hereinafter collectively referred to as“ nitrogen-containing compound (III) ”), amide group-containing compounds , Urea compounds, nitrogen-containing heterocyclic compounds, and the like.

In the general formula (10), a plurality of R ²⁴ are independently of each other a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group, a substituted or unsubstituted aryl group, or a substituted group. Or an unsubstituted aralkyl group is shown.

  Examples of the nitrogen-containing compound (I) include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Di (cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine , Tri-n-nonylamine, tri-n-decylamine, cyclohexyl Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine and tricyclohexylamine; substituted alkylamines such as 2,2 ′, 2 ″ -nitrotriethanol; aniline, N-methylaniline, N, N-dimethylaniline 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-t-butyl-N-methylaniline, N-phenyldiethanolamine Aromatic amines such as 2,6-diisopropylaniline are preferred.

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

  As the nitrogen-containing compound (III), for example, polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer and the like are preferable.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt- Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)-( -)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbonyl Perazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′- Diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N ′, N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N′-di-t-butoxycarbonyl- 1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di -T-butoxycarbonyl-1,10-diaminodecane, N, N'-di-t-butoxycarbonyl-1,12-diaminododecane, N, '-Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenz In addition to Nt-butoxycarbonyl group-containing amino compounds such as imidazole and Nt-butoxycarbonylpyrrolidine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethyl Acetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like are preferable.

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc. are preferred. Examples of the nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2- Imidazoles such as methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine , Nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, pyridines such as 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2-hydroxyethyl ) In addition to piperazines such as piperazine, pyra , Pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3 -(N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like are preferable.

(Photodegradable base)
A photodegradable base is an onium salt compound that loses basicity upon decomposition by exposure. Specific examples of such an onium salt compound include a sulfonium salt compound represented by the following general formula (11) and an iodonium salt compound represented by the following general formula (12).

In the general formulas (11) and (12), R ²⁵ and R ²⁶ each independently represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. Z ⁻ represents OH ⁻ , R ²⁷ —COO ⁻ , R ²⁷ —SO ₃ ^— (wherein R ²⁷ represents an alkyl group, an aryl group, or an alkaryl group), or represented by the following general formula (13). An anion to be produced.

  In the general formula (13), p represents 0 or 1.

  The above acid diffusion control agents can be used singly or in combination of two or more. The compounding amount of the acid diffusion controller is usually 15 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the resin having an acid dissociable group. If the compounding amount of the acid diffusion controller is more than 15 parts by mass, the sensitivity of the resist agent tends to decrease. If the amount of the acid diffusion control agent is less than 0.001 part by mass, the shape and dimensional fidelity of the resist pattern may be lowered depending on the process conditions.

(Additive)
Various additives such as a surfactant, a sensitizer, and an aliphatic additive can be blended with the resist agent as necessary.

  A surfactant is a component that exhibits an effect of improving coating properties, striation, developability, and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. Nonionic surfactants such as polyethylene glycol distearate; hereinafter referred to as KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (above, manufactured by Tochem Products), Megafax F171, F173 (above, manufactured by Dainippon Ink and Chemicals), Florad FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( As mentioned above, Asahi Glass Co., Ltd.) can be mentioned. These surfactants can be used alone or in combination of two or more. The compounding quantity of surfactant is 2 mass parts or less normally with respect to 100 mass parts of resin which has an acid dissociable group.

  The sensitizer absorbs radiation energy and transmits the energy to the acid generator, thereby increasing the amount of acid generated, and has the effect of improving the apparent sensitivity of the resist agent. Have. Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used individually by 1 type or in combination of 2 or more types. Further, by blending a dye or a pigment, the latent image in the exposed area can be visualized, and the influence of halation during exposure can be reduced. Furthermore, adhesiveness with a board | substrate can be improved by mix | blending an adhesion aid. The compounding quantity of a sensitizer is 50 mass parts or less normally with respect to 100 mass parts of resin which has an acid dissociable group.

Examples of the alicyclic additive that can be added to the resist agent include an alicyclic additive having an acid dissociable group and an alicyclic additive having no acid dissociable group. Such an alicyclic additive is a component having an effect of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Specific examples of the alicyclic additive include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone Ester, 1,3-adamantane dicarboxylate di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2,5- Adamantane derivatives such as dimethyl-2,5-di (adamantylcarbonyloxy) hexane; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxy Ethyl, deoxycholic acid -Deoxycholic acid esters such as oxocyclohexyl, deoxycholic acid tetrahydropyranyl, deoxycholic acid mevalonolactone ester; lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2 -Lithocholic acid esters such as cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, Alkyl carboxylic acid esters such as di-t-butyl adipate; 3- (2-hydroxy-2,2-bis (trifluoromethyl) ethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane and the like.

  These alicyclic additives can be used alone or in combination of two or more. The compounding quantity of an alicyclic additive is 50 mass parts or less normally with respect to 100 mass parts of resin which has an acid dissociable group, Preferably it is 30 mass parts or less. When the blending amount of the alicyclic additive is more than 50 parts by mass with respect to 100 parts by mass of the resin having an acid dissociable group, the heat resistance as a resist tends to decrease. Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Mass average molecular weight (Mw) and number average molecular weight (Mn)]: GPC columns manufactured by Tosoh Corporation (two product names “G2000HXL”, one product name “G3000HXL”, one product name “G4000HXL”) are used. , Flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of 40 ° C. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

  [Remaining ratio of low molecular weight component (%)]: Using a trade name “Inertsil ODS-25 μm column” (4.6 mmφ × 250 mm) manufactured by GL Sciences, flow rate: 1.0 mL / min, elution solvent: acrylonitrile / It was measured by high performance liquid chromatography (HPLC) under the analysis condition of 0.1% phosphoric acid aqueous solution. The “low molecular weight component” refers to a component having a monomer as a main component, more specifically, a component having a molecular weight of less than 1,000, preferably a component having a molecular weight equal to or less than that of the trimer.

[ ¹³ C-NMR analysis]: A trade name “JNM-EX400” manufactured by JEOL Ltd. was used, and analysis was performed using DMSO as a measurement solvent.

  [Evaluation of pattern]: Using a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi Keiki Co., Ltd.), the first resist pattern remains in the insolubilized resist pattern formed on the evaluation substrate B. The case where the first resist pattern disappeared was evaluated as “X”. Further, for the second resist pattern formed on the evaluation substrate C, a line-and-and-so pattern is formed between the insolubilized resist patterns formed on the evaluation substrate B so as to have a 50 nm line / 100 nm pitch (50 nm 1 L / 1 S). The case where a space pattern was additionally formed was evaluated as “◯”, and (i) the insolubilized resist pattern disappeared, (ii) the second resist pattern was not formed, or (iii) the second resist pattern was formed. Even when the insolubilized resist pattern was undissolved, it was evaluated as “x”. When a contact hole pattern having a 90 nm hole / 240 nm pitch as shown in FIG. 6 was formed, it was evaluated as “◯ (hole)”.

  [Evaluation of CD variation]: When the evaluation substrate C was formed, the variation in the line width of the insolubilized resist pattern was evaluated as “◎” when the variation in the line width was 2 nm or less, and “◯” when the variation in the insolubilization resist pattern was more than 2 nm and 6 nm or less And those with a size exceeding 6 nm were evaluated as “x”.

(Synthesis Example 1: Resin (A-1))
The compound represented by the following formula (L-1) 53.93 g (50 mol%), the compound represented by the following formula (L-2) 10.69 g (10 mol%), and the following formula (L-3) 35.38 g (40 mol%) of the resulting compound was dissolved in 200 g of 2-butanone, and 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to prepare a monomer solution. A 1000 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes, then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. A cooled polymerization solution was put into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powdery polymer (resin (A-1)) (74 g, yield). 74%). Mw of the obtained resin (A-1) was 6,900, Mw / Mn was 1.70, and the residual ratio of low molecular weight components was 0.03%. Moreover, as a result of ¹³ C-NMR analysis, the obtained resin (A-1) has a repeating unit represented by the following formula (A-1), and the content (mol%) of each repeating unit. Was a / b / c = 53.0 / 9.8 / 37.2.

(Synthesis Example 2: Resin (A-2))
Instead of the compound represented by the formula (L-2), 39.14 g (37 mol%) of the compound represented by the following formula (L-4) was used, which was represented by the formula (L-1). The same procedure as in Synthesis Example 1 except that 50.16 g (50 mol%) of the compound used and 10.70 g (13 mol%) of the compound represented by the formula (L-3) were used were used. To obtain a polymer (resin (A-2)) (78 g, yield 78%). Mw of the obtained resin (A-2) was 5,200, Mw / Mn was 1.62, and the residual ratio of low molecular weight components was 0.03%. Moreover, as a result of ¹³ C-NMR analysis, the obtained resin (A-2) has a repeating unit represented by the following formula (A-2), and the content (mol%) of each repeating unit. Was a / b / c = 50.0 / 37.0 / 13.0.

(Synthesis Example 3: Resin (A-3))
Instead of the compound represented by the formula (L-2), 9.72 g (10 mol%) of the compound represented by the following formula (L-5) was used, which was represented by the formula (L-1). The same procedure as in Synthesis Example 1 except that 54.51 g (50 mol%) of the compound used and 35.76 g (40 mol%) of the compound represented by the formula (L-3) were used were used. To obtain a polymer (resin (A-3)) (71 g, yield 71%). Mw of the obtained resin (A-3) was 8,100, Mw / Mn was 1.69, and the residual ratio of the low molecular weight component was 0.04%. Moreover, as a result of ¹³ C-NMR analysis, the obtained resin (A-3) has a repeating unit represented by the following formula (A-3), and the content of each repeating unit (mol%). Was a / b / c = 53.6 / 9.8 / 36.6.

(Synthesis Example 4: Resin (A-4))
Instead of the compound represented by the formula (L-2), 24.42 g (15 mol%) of a compound represented by the following formula (L-6) was used, which was represented by the formula (L-3). In place of the compound, 30.40 g (40 mol%) of the compound represented by the following formula (L-7) was used, and 45.18 g (45 mol%) of the compound represented by the formula (L-1) was used. ) A polymer (resin (A-4)) was obtained in the same manner as in Synthesis Example 1 except that it was used (75 g, yield 75%). Mw of the obtained resin (A-4) was 6,100, Mw / Mn was 1.73, and the residual ratio of low molecular weight components was 0.04%. As a result of ¹³ C-NMR analysis, the obtained resin (A-4) has a repeating unit represented by the following formula (A-4), and the content (mol%) of each repeating unit. Was a / b / c = 44.1 / 15.5 / 40.4.

(Synthesis Example 5: Resin (A-5))
Instead of the compound represented by the formula (L-2), 35.6 g (35 mol%) of the compound represented by the formula (L-4) was used, which was represented by the formula (L-3). In place of the compound, 16.17 g (15 mol%) of the compound represented by the following formula (L-8) was used, and 48.23 g (50 mol%) of the compound represented by the formula (L-1) was used. ) A polymer (resin (A-5)) was obtained in the same manner as in Synthesis Example 1 except that it was used (72 g, yield 72%). Mw of the obtained resin (A-5) was 8,200, Mw / Mn was 1.78, and the residual ratio of low molecular weight components was 0.03%. As a result of ¹³ C-NMR analysis, the obtained resin (A-5) has a repeating unit represented by the following formula (A-5), and the content (mol%) of each repeating unit. Was a / b / c = 50.0 / 36.9 / 13.1.

(Preparation of resist agent)
Using the resins (A-1) to (A-5) synthesized in Synthesis Examples 1 to 5, the acid generator, the acid diffusion controller, and the solvent, the first resist agent (1) according to the formulation shown in Table 1 To (7) and second resist agents (8) to (12) were prepared. The types of acid generator, acid diffusion controller and solvent used are shown below.

<Acid generator>
(D-1): 4-Nonafluoro-n-butylsulfonyloxyphenyldiphenylsulfonium nonafluoro-n-butanesulfonate (D-2): Triphenylsulfonium nonafluoro-n-butanesulfonate (D-3): Triphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate (D-4): triphenylsulfonium 2- (bicyclo [2.2.1] Heptan-2-yl) -1,1-difluoroethanesulfonate

<Acid diffusion control agent>
(E-1): (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol Nt-butoxycarbonylpyrrolidine (E-2): triphenylsulfonium salicylate (E-3 ): Triphenylsulfonium 10-camphorsulfonate

<Solvent>
(F-1): Propylene glycol monomethyl ether acetate (F-2): γ-butyrolactone

(Synthesis Example 6: Polymer (B-1))
1,1,1-trifluoro-2-hydroxy-2- (trifluoromethyl) pent-4-yl methacrylate (hereinafter referred to as “monomer (m-1)” represented by the following formula (m-1) 50.00 g) and 1.57 g of dimethyl 2,2′-azobisisobutyrate (MAIB) were dissolved in 50 g of methyl ethyl ketone (MEK) to prepare a solution. The prepared solution was dropped into a reaction vessel containing 50 g of MEK over 1 hour under reflux conditions (82 ° C.), and then a polymerization reaction was performed for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer (B-1) was obtained from the obtained MIBC solution (yield 70%). Mw of the obtained polymer (B-1) was 10,000, and Mw / Mn was 1.51.

(Synthesis Example 7: Polymer (B-2))
39.78 g of monomer (m-1), 10.22 g of pt-butoxystyrene (hereinafter also referred to as “monomer (m-2)”) represented by the following formula (m-2), and A solution was prepared by dissolving 1.27 g of AIBN in 50 g of MEK. The prepared solution was dropped into a reaction vessel containing 50 g of MEK over 1 hour under reflux conditions (82 ° C.), and then a polymerization reaction was performed for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-2) was obtained from the obtained MIBC solution (yield 66%). Mw of the obtained polymer (B-2) was 10,500, and Mw / Mn was 1.52. Moreover, as a result of ¹³ C-NMR analysis, the ratio (mol%) of repeating units derived from the respective monomers contained in the obtained polymer (B-2) was (m−1) / (m -2) = 70.5 / 29.5.

(Synthesis Example 8: Polymer (B-3))
Monomer (m-1) 47.45 g, glycidyl methacrylate (hereinafter also referred to as “monomer (m-3)”) 2.55 g represented by the following formula (m-3), and AIBN 2.94 g A solution was prepared by dissolving in 50 g of MEK. The prepared solution was dropped into a reaction vessel containing 50 g of MEK over 1 hour under reflux conditions (82 ° C.), and then a polymerization reaction was performed for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-3) was obtained from the obtained MIBC solution (yield 70%). Mw of the obtained polymer (B-3) was 12,500, and Mw / Mn was 1.51. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-3) as a result of ¹³ C-NMR analysis is (m-1) / (m -3) = 88.2 / 11.8.

(Synthesis Example 9: Polymer (B-4))
A solution was prepared by dissolving 39.74 g of monomer (m-1) and 0.95 g of AIBN in 33.33 g of MEK. A reaction in which 10.26 g of 4-hydroxymethacrylanilide (hereinafter also referred to as a monomer “(m-4)”) represented by the following formula (m-4) and 66.67 g of MEK were added to the prepared solution. After dropping into the vessel under reflux conditions (82 ° C.) over 1 hour, a polymerization reaction was carried out for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-4) was obtained from the obtained MIBC solution (yield 72%). Mw of the obtained polymer (B-4) was 15,500, and Mw / Mn was 1.51. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-4) as a result of ¹³ C-NMR analysis is (m−1) / (m -4) = 88.2 / 11.8.

(Synthesis Example 10: Polymer (B-5))
44.61 g of monomer (m-1), 5.39 g of butyl methacrylate represented by the following formula (m-5) (hereinafter also referred to as “monomer (m-5)”), and 0.93 g of AIBN A solution was prepared by dissolving in 66.67 g of MEK. The prepared solution was dropped into a reaction vessel containing 33.33 g of MEK over 1 hour under reflux conditions (82 ° C.), and then a polymerization reaction was performed for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-5) was obtained from the obtained MIBC solution (yield 68%). Mw of the obtained polymer (B-5) was 17,000, and Mw / Mn was 1.52. Moreover, as a result of ¹³ C-NMR analysis, the ratio (mol%) of repeating units derived from the respective monomers contained in the obtained polymer (B-5) was (m−1) / (m −5) = 80.2 / 19.8.

(Synthesis Example 11: Polymer (B-6))
42.03 g of monomer (m-1), 7.97 g of hydroxyethyl methacrylate represented by the following formula (m-6) (hereinafter also referred to as “monomer (m-6)”), and 0.84 g of AIBN Was dissolved in 66.67 g of MEK to prepare a solution. The prepared solution was dropped into a reaction vessel containing 33.33 g of MEK over 1 hour under reflux conditions (82 ° C.), and then a polymerization reaction was performed for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-6) was obtained from the obtained MIBC solution (yield 72%). Mw of the obtained polymer (B-6) was 15,800, and Mw / Mn was 1.50. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-6) as a result of ¹³ C-NMR analysis was (m−1) / (m −6) = 70.5 / 29.5.

(Synthesis Example 12: Polymer (B-7))
40.71 g of monomer (m-1), 9.29 g of tridecyl methacrylate (hereinafter also referred to as “monomer (m-7)”) represented by the following formula (m-7), and 1.14 g of AIBN Was dissolved in 66.67 g of MEK to prepare a solution. The prepared solution was dropped into a reaction vessel containing 33.33 g of MEK over 1 hour under reflux conditions (82 ° C.), and then a polymerization reaction was performed for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-7) was obtained from the obtained MIBC solution (yield 70%). Mw of the obtained polymer (B-7) was 15,000, and Mw / Mn was 1.52. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-7) as a result of ¹³ C-NMR analysis was (m−1) / (m −7) = 79.5 / 29.5.

(Synthesis Example 13: Polymer (B-8))
A solution was prepared by dissolving 43.01 g of monomer (m-1) and 1.50 g of AIBN in 33.33 g of MEK. The prepared solution was dropped into a reaction vessel containing 6.99 g of a compound represented by the following formula (m-8) and 66.67 g of MEK over 1 hour under reflux conditions (82 ° C.) for 3 hours. A polymerization reaction was performed. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-8) was obtained from the obtained MIBC solution (yield 76%). Mw of the obtained polymer (B-8) was 13,500, and Mw / Mn was 1.68. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-8) as a result of ¹³ C-NMR analysis was (m−1) / (m −8) = 82.3 / 17.7.

(Synthesis Example 14: Polymer (B-9))
A solution was prepared by dissolving 39.70 g of the monomer (m-1) and 1.58 g of AIBN in 33.33 g of MEK. The prepared solution was dropped into a reaction vessel containing 10.30 g of the compound represented by the following formula (m-9) and 66.67 g of MEK over 1 hour under reflux conditions (82 ° C.) for 3 hours. A polymerization reaction was performed. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-9) was obtained from the obtained MIBC solution (yield 76%). Mw of the obtained polymer (B-9) was 12,800, and Mw / Mn was 1.60. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-9) as a result of ¹³ C-NMR analysis was (m−1) / (m −9) = 71.7 / 28.3.

(Synthesis Example 15: Polymer (B-10))
A solution was prepared by dissolving 23.28 g of the monomer (m-10) represented by the following formula and 1.77 g of AIBN in 33.33 g of MEK. The prepared solution was dropped into a reaction vessel containing 26.72 g of monomer (m-4) and 66.67 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. It was. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with MIBC, and a polymer (B-10) was obtained from the obtained MIBC solution (yield 69%). Mw of the obtained polymer (B-10) was 17,100, and Mw / Mn was 1.72. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-10) as a result of ¹³ C-NMR analysis was (m-10) / (m -4) = 34.2 / 65.8.

(Synthesis Example 16: Polymer (B-11))
31.30 g of monomer (m-1), 41.47 g of monomer (m-4), 27.23 g of monomer (m-5), and 3.93 g of azobisisobutyronitrile (AIBN) The solution was put into a reaction vessel containing 300 g of isopropyl alcohol (IPA) and dissolved, and a polymerization reaction was carried out under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 200 g of ethyl acetate, 140 g of methanol and 140 g of IPA were added and stirred, and 600 g of water was added thereto and allowed to stand for 3 hours. The precipitated resin component was collected and solvent-substituted with MIBC, and a polymer (B-11) was obtained from the obtained MIBC solution (yield 82%). Mw of the obtained polymer (B-11) was 15,500, and Mw / Mn was 2.13. Moreover, as a result of ¹³ C-NMR analysis, the ratio (mol%) of repeating units derived from the respective monomers contained in the obtained polymer (B-11) was (m−1) / (m -4) / (m-5) = 20.2 / 43.8 / 36.0.

(Synthesis Example 17: Polymer (B-12))
16.65 g of monomer (m-1), 55.17 g of monomer (m-4), 28.17 g of monomer (m-5), and 4.18 g of AIBN were charged into a reaction vessel containing 300 g of IPA. The solution was dissolved and subjected to a polymerization reaction under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 200 g of ethyl acetate, 140 g of methanol and 140 g of IPA were added and stirred, and 600 g of water was added thereto and allowed to stand for 3 hours. The precipitated resin component was collected and solvent-substituted with MIBC, and a polymer (B-12) was obtained from the obtained MIBC solution (yield 85%). Mw of the obtained polymer (B-12) was 14,500, and Mw / Mn was 1.95. Moreover, as a result of ¹³ C-NMR analysis, the ratio (mol%) of repeating units derived from the respective monomers contained in the obtained polymer (B-12) was (m−1) / (m -4) / (m-5) = 10.5 / 55.8 / 33.7.

(Synthesis Example 18: Polymer (B-13))
Monomer (m-1) 23.73 g, monomer (m-3) 19.11 g, monomer (m-4) 57.17 g, and AIBN 4.41 g were charged into a reaction vessel containing IPA 300 g. The solution was dissolved and subjected to a polymerization reaction under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 200 g of ethyl acetate, 140 g of methanol and 140 g of IPA were added and stirred, and 600 g of water was added thereto and allowed to stand for 3 hours. The precipitated resin component was collected and solvent-substituted with MIBC, and a polymer (B-13) was obtained from the obtained MIBC solution (yield 85%). Mw of the obtained polymer (B-13) was 13,800, and Mw / Mn was 1.83. Moreover, the ratio (mol%) of the repeating unit derived from each monomer contained in the obtained polymer (B-13) as a result of ¹³ C-NMR analysis was (m−1) / (m -3) / (m-4) = 14.7 / 26.5 / 58.8.

Example 1
100 parts of the polymer (B-1), 30 parts of the crosslinking component (C-1), and 2620 parts of the solvent (F-3) were mixed and stirred for 3 hours, and then filtered through a filter with a pore size of 0.03 μm to insolubilize. A resin composition (A) was prepared.

(Examples 2 to 25)
Insolubilized resin compositions (B) to (Y) were prepared by the same operation as in Example 1 except that the formulation shown in Table 2 was used. In addition, the kind of crosslinking component and solvent used are shown below.

<Crosslinking component>
C-1: Product name “Nikarak MX-750” (manufactured by Nippon Carbide)
C-2: Pentaerythritol tetraacrylate C-3: Trade name “OXIPA” (manufactured by Ube Industries)
C-4: Pentaerythritol triacrylate

<Solvent>
F-3: 1-butanol F-4: 4-methyl-2-pentanol

(Reference Example 1)
A 12-inch silicon wafer was spin-coated with a lower antireflection film (trade name “ARC29A”, manufactured by Brewer Science) using a trade name “CLEAN TRACK ACT12” (manufactured by Tokyo Electron), and then PB (205 (C, 60 seconds) to form a 77 nm-thickness coating film. Using the trade name “CLEAN TRACK ACT12”, spin coat the first resist agent (1), PB (115 ° C., 60 seconds), and then cool (23 ° C., 30 seconds) to coat 150 nm thick. A film was formed. Next, using an ArF immersion exposure apparatus (trade name “XT1250i”, manufactured by ASML), NA: 0.85, Outer / Inner = 0.89 / 0.59 Annular optical conditions, 50 nm line / 200 nm pitch The exposure was carried out through a mask having a mask size of. After PEB (115 ° C., 60 seconds) on a hot plate of the trade name “CLEAN TRACK ACT12”, it was cooled (23 ° C., 30 seconds), and 2.38% tetramethylammonium hydroxide was used with the LD nozzle of the developing cup. Paddle development (30 seconds) was performed using the aqueous solution as a developer, and rinsed with ultrapure water. The substrate A for evaluation on which the first resist pattern was formed was obtained by spin-drying by shaking off at 2000 rpm for 15 seconds.

  The insolubilized resin composition (A) prepared in Example 1 was spin-coated on the first resist pattern of the obtained evaluation substrate A using the trade name “CLEAN TRACK ACT12” to obtain a film thickness of 150 nm. After application, PB before washing (130 ° C., 60 seconds) was performed. Using the product name “CLEAN TRACK ACT12”, cooling with a cooling plate at 23 ° C. for 30 seconds, and then using a LD nozzle of the developing cup with a 2.38% tetramethylammonium hydroxide aqueous solution as a developer for paddle development (60 seconds) And rinsed with ultrapure water. Spin-drying was performed by shaking off at 2000 rpm for 15 seconds. After cleaning, PB (165 ° C., 90 seconds) was performed to obtain an evaluation substrate B (1) on which an insolubilized resist pattern was formed.

(Reference Examples 2-37)
A substrate for evaluation B on which an insolubilized resist pattern was formed by the same operation as in Reference Example 1 except that the first resist agent and the insolubilized resin composition shown in Table 3 were used and the conditions shown in Table 3 were used. 2) to (37) were obtained. However, in Reference Examples 13 to 16, 21 to 24, and 37, the first resist pattern was formed with a 150 nm line / 240 nm pitch.

(Reference Examples 38 to 40)
Evaluation board | substrate A was obtained by operation similar to the reference example 1 except having used each 1st resist agent shown in Table 3, and having set it as the conditions shown in Table 3. FIG. The obtained evaluation substrate A was used as it was as the evaluation substrates B (38) to (40) without being treated with the insolubilized resin composition.

(Example 26)
On the insolubilized resist pattern of the evaluation substrate B (1), the second resist agent (8) was spin-coated using a trade name “CLEAN TRACK ACT12”, PB (100 ° C., 60 seconds), and then cooled ( 23 ° C. for 30 seconds) to form a coating film having a thickness of 150 nm. Using an ArF immersion exposure apparatus, the space of the insolubilized resist pattern through a mask having a mask size of 50 nm line / 200 nm pitch under the optical conditions of NA: 0.85 and Outer / Inner = 0.89 / 0.59 Annular The part was exposed. After PEB (95 ° C., 60 seconds) on a hot plate of the trade name “CLEAN TRACK ACT12”, it was cooled (23 ° C., 30 seconds), and 2.38% tetramethylammonium hydroxide was used in the LD nozzle of the developing cup. Paddle development (30 seconds) was performed using the aqueous solution as a developer, and rinsed with ultrapure water. The substrate for evaluation C on which the second resist pattern was formed was obtained by spin-drying by shaking off at 2000 rpm for 15 seconds. The evaluation of the pattern of the obtained substrate for evaluation C was “◯”, and the evaluation of CD variation was “◯”.

(Examples 27 to 62)
Using each evaluation substrate B obtained in Reference Examples 2 to 37 and the second resist agent described in Table 4, respectively, except that the conditions shown in Table 4 were used, the same operation as in Example 26 described above, Each evaluation substrate C on which the second resist pattern was formed was obtained. However, in Examples 38 to 41, 46 to 49, and 62, the second resist pattern was formed at a 150 nm line / 240 nm pitch so that a contact hole pattern as shown in FIG. It formed so that it might intersect with the insolubilization resist pattern formed in 16, 21, 24, or 37, and each evaluation board | substrate C was obtained. Table 4 shows the evaluation of the pattern of each evaluation substrate C obtained and the evaluation of CD fluctuation.

(Comparative Examples 1-3)
Using evaluation substrates B (38) to (40) obtained in Reference Examples 38 to 40 (those not treated with the insolubilized resin composition), Table 4 was formed on the first resist pattern of each evaluation substrate B. Each evaluation substrate C was manufactured by the same operation as in Example 26 except that the second resist pattern was formed under the conditions shown in FIG. Table 4 shows the evaluation of the pattern of the obtained substrate for evaluation C and the evaluation of CD fluctuation.

  From the results shown in Table 4, it is clear that line width fluctuations during pattern formation can be controlled by using the insolubilized resin compositions of Examples 1 to 25 (Examples 26 to 62).

  The resist pattern forming method of the present invention is a method that is very suitably employed in the field of microfabrication represented by the manufacture of integrated circuit elements that are expected to be increasingly miniaturized in the future.

1: first resist pattern, 1a: first line portion, 1b: first space portion, 2, 22, 32: second resist pattern, 2a, 22a, 32a: second line portion, 2b, 22b, 32b : Second space part, 3a: third line part, 3b: third space part, 3: insolubilized resist pattern, 5: insoluble film, 10: substrate, 12: resist layer, 15: contact hole.

Claims (4)

On the first resist pattern formed on the substrate, a resist pattern insolubilized resin composition containing a polymer containing a repeating unit represented by the following general formula (1) and a solvent is applied and baked or UV cured. Thereafter, washing and insolubilizing the first resist pattern with respect to the developer and the radiation-sensitive resin composition to form an insolubilized resist pattern on the substrate (1);
Using the radiation sensitive resin composition, forming a resist layer on the substrate on which the insolubilized resist pattern is formed, and selectively exposing the resist layer;
And a step (3) of developing to form a second resist pattern.

(In the general formula (1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² represents a single bond, a methylene group, a linear or branched chain having 2 to 6 carbon atoms. Represents an alkylene group or an alicyclic hydrocarbon group having 4 to 12 carbon atoms.) A resist pattern insolubilized resin composition containing a polymer containing a repeating unit represented by the following general formula (1) and a solvent, which is used in step (1) of the resist pattern forming method according to claim 1.

(In the general formula (1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² represents a single bond, a methylene group, a linear or branched chain having 2 to 6 carbon atoms. Represents an alkylene group or an alicyclic hydrocarbon group having 4 to 12 carbon atoms.) The resist pattern insolubilized resin composition according to claim 2, wherein the polymer further contains a repeating unit derived from a monomer represented by the following general formula (2).

(In the general formula (2), R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and A represents a single bond or a linear or branched alkylene having 1 to 5 carbon atoms. groups, -NH -, - O -, - COO-, or ^{-CONH-R 5} -. indicates, m is 1 or 2, n represents an integer of 0 to 2 provided that, ^{R 5} represents a single bond, or A linear, branched or cyclic divalent hydrocarbon group is shown.)   The resist pattern insolubilized resin composition according to claim 2 or 3, wherein the solvent is an alcohol solvent.

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