JP2010044164A - Resist pattern-forming method and positive-type radiation-sensitive composition used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist pattern-forming method which easily, efficiently forms finer resist patterns. <P>SOLUTION: The resist pattern-forming method includes: (1) a process in which a resin composition, which makes a resist pattern insoluble, is applied to a first resist pattern, and development is carried out after baking or UV curing, and the first resist pattern is made to be an insoluble resist pattern having a plurality of first line parts and first space parts; (2) a process in which resist layers formed in the first space parts by using a positive-type radiation-sensitive resin composition are selectively subjected to exposure via a mask; and (3) a process in which development is carried out to form second line parts in the first space parts, and a second resist pattern is formed, the second resist pattern having the first line parts, the second line parts, and one or more second space parts whose widths (W<SB>2</SB>) are over 0% and at most 30% of the widths (W<SB>1</SB>) of the first space parts, the second space parts being formed between the first and second line parts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for forming a fine resist pattern using a resin composition capable of insolubilizing a resist pattern, and a positive radiation-sensitive resin composition used therefor.

  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. However, in the conventional lithography process, near-ultraviolet rays such as i-rays are generally used as radiation, and it is said that fine processing at a 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, an X-ray, an electron beam, and the like. Among these, a KrF excimer laser (wavelength 248 nm) is particularly preferable. ) Or ArF excimer laser (wavelength 193 nm) has been 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 an acid upon irradiation with radiation (hereinafter also referred to as “exposure”) (hereinafter referred to as “acid generator”) Many resists using the chemical amplification effect (hereinafter also referred to as “chemically amplified resist”) have been proposed. As the chemically amplified resist, for example, a resist containing a resin having a tert-butyl ester group of carboxylic acid or a tert-butyl carbonate group of phenol and an acid generator has been proposed (see, for example, Patent Document 1). ). In this resist, the tert-butyl ester group or tert-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 exposed 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 fine pattern formation of less than 45 nm, 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, a new expensive exposure apparatus is required to shorten the light source wavelength. 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.

  Recently, as a lithography technique capable of solving such a problem, a method called an immersion exposure (liquid immersion lithography) method has been reported (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 a fluorine-based inert liquid having a predetermined thickness on at least the resist film between the lens and the resist film on the substrate. Is to intervene. In this method, a light source having the same exposure wavelength can be 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. Similar to 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. If such immersion exposure is used, it is possible to realize the formation of a resist pattern that is low in cost, excellent in high resolution, and excellent in depth of focus, using a lens mounted on an existing apparatus. It has attracted a great deal of attention and is being put to practical use.

  However, it is said that the extension of the above-described 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, with the demand for higher complexity and higher density of such devices, a technique for patterning 32 nm LS by sparse line patterns such as double patterning or double exposure or by overlapping half-cycles of isolated trench patterns has been proposed. (For example, refer nonpatent literature 1).

  In one of the proposed examples, a 32 nm line with a 1: 3 pitch is formed and then processed by etching, and at a position shifted by a half cycle from the first resist pattern, the pitch is similarly 1: 3. A 32 nm line is formed and processed again by etching. As a result, a 32 nm line having a pitch of 1: 1 is finally formed. However, although there are proposals for several processes as described above, no proposals for more specific and practical methods have yet been made.

Japanese Patent Laid-Open No. 5-232704 JP-A-10-303114 SPIE 2006 Vol. 6153 6153K

  The present invention has been made in view of such problems of the prior art, and the problem is that a resist pattern forming method capable of easily and efficiently forming a finer resist pattern, Another object of the present invention is to provide a positive radiation sensitive resin composition used in this resist pattern forming method.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors formed a resist layer in a space portion of a resist pattern insolubilized with a developer using a predetermined resin composition, and formed the resist layer Furthermore, it discovered that the said subject could be achieved by exposing and developing, and came to complete this invention.

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

[1] (1) A resist pattern insolubilizing resin composition containing a hydroxyl group-containing resin and an alcohol solvent is applied on the first resist pattern, and after baking or UV curing, development is performed, and the first resist is developed. (2) the positive radiation sensitivity, wherein the pattern is an insolubilized resist pattern having a plurality of first line portions and first space portions insoluble in the developer and the positive radiation sensitive resin composition; Forming a resist layer at least in the first space using a resin composition, and selectively exposing the formed resist layer through a mask; and (3) developing the first space. Forming a second line part in the part, the width (W ₂ ) formed between the first line part, the second line part, and the first line part and the second line part, in front Forming a second resist pattern having one or more second space portion is 30% or less than 0% of the width of the first space portion (W _1),
A resist pattern forming method comprising:

[2] (1) A resist pattern insolubilized resin composition containing a hydroxyl group-containing resin and an alcohol solvent is applied onto the first resist pattern, and after baking or UV curing, development is performed, and the first resist is developed. (2) the positive radiation sensitivity, wherein the pattern is an insolubilized resist pattern having a plurality of first line portions and first space portions insoluble in the developer and the positive radiation sensitive resin composition; Forming a resist layer at least in the first space using a resin composition, and selectively exposing the formed resist layer through a mask; and (3) developing the first space. Forming a second line part in the part, the width (W ₂ ) formed between the first line part, the second line part, and the first line part and the second line part, in front Forming a second resist pattern having a second space portion is 0-30% of the first space portion of the width (W _1), used in the step of a method of forming a resist pattern having a (2), A positive radiation sensitive resin composition containing a resin having a repeating unit represented by the following general formula (1).

In the general formula (1), R ¹ represents hydrogen or a methyl group, and a plurality of R ² are independently of each other a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, Or a C1-C4 linear or branched alkyl group is shown. (I) at least one of R ² is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof; or (ii) any two R ² are bonded to each other. And a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing carbon atoms to which each is bonded, and the remaining R ² is a straight chain having 1 to 4 carbon atoms Alternatively, it is a branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof.

  According to the resist pattern forming method of the present invention, a finer resist pattern can be easily and efficiently formed.

  Further, the positive radiation sensitive resin composition of the present invention is suitably used in an intermediate step of the above-described resist pattern forming method capable of easily and efficiently forming a finer resist pattern.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention. Hereinafter, the “first positive radiation sensitive resin composition” and the “second positive radiation sensitive resin composition” are also simply referred to as “first resist agent” and “second resist agent”, respectively. The “resist pattern insolubilized resin composition” is also simply referred to as “insolubilized resin composition”.

((1) Process)
In the step (1), a resist pattern insolubilized resin composition containing a hydroxyl group-containing resin and an alcohol solvent is applied onto the first resist pattern, developed after baking or UV curing, Is an insolubilized resist pattern having a plurality of first line portions and a plurality of first space portions that are insoluble in the developer and the positive-type radiation-sensitive resin composition. The first resist pattern is formed on a substrate such as a silicon wafer or a wafer coated with SiN or an organic antireflection film, for example, by a suitable application means such as spin coating, cast coating, roll coating, or the like. A resist layer (first resist layer) is formed by applying a radiation resin composition (first positive radiation-sensitive resin composition), and the first resist layer thus formed is selectively exposed through a mask. Then, it can be formed by developing.

  After applying the first resist agent on the substrate, the solvent in the coating film may be volatilized by pre-baking (PB) if necessary. Although the prebaking heating conditions are appropriately selected depending on the composition of the first resist agent, they are usually 30 to 200 ° C, preferably 50 to 150 ° C.

  In order to maximize the potential of the first resist agent, an organic or inorganic antireflection film is formed on the substrate as disclosed in, for example, Japanese Patent Publication No. 6-12458. It ’s good to leave. 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 required region of the formed first resist layer is exposed 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 first resist agent, but ArF excimer laser ( Far ultraviolet rays typified by a wavelength of 193 nm) and KrF excimer laser (wavelength 248 nm) are preferred, and an ArF excimer laser (wavelength 193 nm) is particularly preferred. In addition, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a 1st resist agent, the kind of additive, etc. 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, preferably 50 to 170 ° C.

  By developing the exposed first resist layer, the pattern latent image portion is exposed, and a positive first resist pattern 1 having a predetermined space portion as shown in FIG. 1 is formed on the substrate 10. The 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.

An insolubilized resin composition is applied onto the first resist pattern formed according to the above-described procedure by an appropriate application means such as spin coating, cast coating, or roll coating. At this time, the insolubilized resin composition is applied so that the first resist pattern is covered. After applying the insolubilized resin composition, heat treatment (baking) or UV curing is performed. 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, they are 30-200 degreeC normally, Preferably 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 it develops after cooling suitably, as shown in FIG.2 and FIG.3, the surface of the 1st resist pattern 1 was coat | covered with the insoluble film | membrane 5 which consists of a resin composition, and the 1st line part 1a and 1st The insolubilized resist pattern 3 that is a line-and-space pattern having a plurality of space portions 1b can be formed. The insolubilized resist pattern 3 (first line portion 1a) to be formed is insoluble or hardly soluble in the developer and the positive radiation-sensitive resin composition (second resist agent) used in the step (2). It is. 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 when the second 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 (1) process in multiple times as needed.

((2) Process)
In the step (2), as shown in FIG. 4, the second positive radiation sensitive radiation 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. The photosensitive resin composition (second resist agent) is applied, and the second resist layer 12 made of the second resist agent is formed at least in the first space portion 1b. Thereafter, as in the case where the first resist layer is formed, pre-baking (PB) may be performed as necessary. Next, as in the case of forming the first resist pattern, selective exposure is performed through a mask having a predetermined opening pattern. Note that heat treatment (PEB) may be further performed as necessary.

  At the time of exposure, for example, as shown in FIG. 4, in the second resist layer 12 formed in the first space portion 1b, a region having a predetermined width from the side surface of the first line portion 1a is set as an exposure region, and other regions are set as the exposure region. A non-exposed area is assumed. In addition, as shown in FIG. 4, you may expose the area | region corresponding to the upper surface of the 1st line part 1a.

((3) Process)
In step (3), development is performed in the same manner as in step (1) to form a second line portion in the first space portion. As a result, the first line portion 1a, the second line portion 2a, and the second space portion 2b formed between the first line portion 1a and the second line portion 2a as shown in FIGS. The positive type second resist pattern 2 can be formed. By the above steps, as shown in FIGS. 5 and 6, the width (W ₂ ) exceeds 0% of the width W ₁ of the first space part and is 30% or less, preferably more than 0% and 25%. In the following, it is possible to form one or more second space portions 2b that are more preferably more than 0% and 20% or less. If the resist pattern formed in this way is used, a semiconductor can be manufactured.

In the step (2), a resist pattern in a desired arrangement state can be formed by appropriately selecting an opening pattern of a mask used for selective exposure. Specifically, when the width W ₁ of the first space portion is, for example, 2 to 1000 nm, preferably 10 to 800 nm, and more preferably 10 to 750 nm, the width W ₂ of the second space portion is usually 1 It can be set to ˜999 nm, preferably 1 to 799 nm, more preferably 1 to 749 nm.

  In addition, in FIG. 5, although the example which formed the 2nd line part 2a high compared with the 1st line part 1a is shown, the thickness of the 2nd resist layer formed at (2) process is set arbitrarily Therefore, the height of the second line portion 2a and the height of the first line portion 1a can be made uniform (the same).

(Resist pattern insolubilized resin composition)
The insolubilized resin composition used in step (1) of the present invention is capable of insolubilizing the first resist pattern with respect to the developer and the positive radiation sensitive resin composition. This insolubilized resin composition contains a resin having a hydroxyl group and an alcohol solvent.

(Resin having a hydroxyl group)
Resin having a hydroxyl group contained in the insolubilized resin composition (hereinafter also referred to as “hydroxyl group-containing resin”) is a hydroxyl group (—OH) derived from at least one selected from the group consisting of alcohols, phenols, and carboxylic acids. It is preferable that it is resin containing the structural unit which has).

  The hydroxyl group-containing resin is obtained by copolymerizing a monomer component including a monomer having at least one hydroxyl group selected from the group consisting of alcoholic hydroxyl groups, hydroxyl groups derived from organic acids such as carboxylic acids, and phenolic hydroxyl groups. Can be obtained. Specific examples of the monomer having an alcoholic hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, Mention may be made of hydroxyalkyl (meth) acrylates such as glycerol monomethacrylate. Of these, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferable. These monomers can be used individually by 1 type or in combination of 2 or more types. The proportion of the monomer having an alcoholic hydroxyl group is usually 5 to 90 mol%, preferably 10 to 60 mol%, based on all monomers constituting the hydroxyl group-containing resin.

  Specific examples of monomers having a hydroxyl group derived from an organic acid such as carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, 2-succinoloylethyl (meth) acrylate, and 2-malenoylethyl (meth) acrylate. 2-hexahydrophthaloylethyl (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate, monohydroxyethyl acrylate phthalate, acrylic acid dimer, 2-hydroxy-3-phenoxypropyl acrylate, t-butoxy methacrylate, t- Examples thereof include monocarboxylic acids such as butyl acrylate; (meth) acrylic acid derivatives having a carboxyl group, including dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid. Of these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloylethyl methacrylate are preferable. These monomers can be used individually by 1 type or in combination of 2 or more types. Moreover, the usage-amount of these monomers is 5-90 mol% normally with respect to all the monomers which comprise a hydroxyl-containing resin, Preferably it is 10-60 mol%.

  An example of a commercial product of ω-carboxy-polycaprolactone monoacrylate is “Aronix M-5300” manufactured by Toagosei Co., Ltd. Moreover, as a commercial item of an acrylic acid dimer, there exists a brand name "Aronix M-5600" by Toagosei Co., Ltd., for example. Furthermore, as a commercial item of 2-hydroxy-3-phenoxypropyl acrylate, there is a trade name “Aronix M-5700” manufactured by Toagosei Co., Ltd., for example.

  Specific examples of the monomer having a phenolic hydroxyl group 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 -Dimethoxyphenol, 4-allyloxy-2-hydroxybenzophenone, etc. can be mentioned. Of these, p-hydroxystyrene and α-methyl-p-hydroxystyrene are preferable.

  Moreover, as a monomer which has a phenolic hydroxyl group, the monomer which has an amide bond (it has an amide group) in the molecule | numerator is preferable. Preferable examples of such a monomer include a monomer represented by the following general formula (2).

In the general formula (2), R ³ and R ⁵ represent hydrogen or a methyl group, and R ⁴ represents a single bond or a linear or cyclic divalent hydrocarbon group. Specific examples of R ⁴ include methylene group, ethylene group, propylene group (1,3-propylene group, 1,2-propylene group), tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group. Group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptacamethylene group, octadecamethylene group, nonacamethylene group 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 -Saturated chain hydrocarbon groups such as methyl-1,4-butylene group, ethylidene group, propylidene group, 2-propylidene group , Cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, cyclohexylene groups such as 1,4-cyclohexylene groups, 1,5-cyclooctylene groups A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms including a cyclooctylene group such as 1, nornorylene group such as 1,4-norbornylene group and 2,5-norbornylene group, 1,5 -Mention may be made of a bridged cyclic hydrocarbon ring group such as a 2-4 cyclic hydrocarbon ring group having 4 to 30 carbon atoms such as an adamantylene group such as an adamantylene group or a 2,6-adamantylene group. it can. In addition, as a monomer represented by the said General formula (5), p-hydroxymethacrylanilide is preferable. The proportion of the monomer having a phenolic hydroxyl group represented by the general formula (5) is usually 30 to 95 mol%, preferably 40 to 90 mol, based on all monomers constituting the hydroxyl group-containing resin. %.

  In addition, the monomer (specific functional group containing monomer) which has a specific functional group which can be converted into a phenolic hydroxyl group after copolymerization can also be copolymerized. Specific examples of the specific functional group-containing monomer include p-acetoxystyrene, α-methyl-p-acetoxystyrene, p-benzyloxystyrene, p-tert-butoxystyrene, and p-tert-butoxycarbonyloxystyrene. , P-tert-butyldimethylsiloxystyrene and the like. If the resin obtained by copolymerizing these specific functional group-containing monomers is subjected to appropriate treatment such as hydrolysis using hydrochloric acid or the like, the specific functional group is easily converted into a phenolic hydroxyl group. be able to. The proportion of the specific functional group-containing monomer is usually 5 to 90 mol%, preferably 10 to 80 mol%, based on all monomers constituting the hydroxyl group-containing resin.

  The proportion of these monomers having an alcoholic hydroxyl group, monomers having a hydroxyl group derived from an organic acid such as carboxylic acid, and monomers having a phenolic hydroxyl group are all monomers constituting the hydroxyl group-containing resin. On the other hand, each is usually within the above-mentioned range. When the content ratio of the structural unit having a hydroxyl group is too small, there are too few reaction sites with a crosslinking component described later, and thus the resist pattern does not easily shrink. On the other hand, if the content ratio of the structural unit having a hydroxyl group is too large, the resist pattern may be buried due to swelling during development.

  The hydroxyl group-containing resin is preferably a resin having a repeating unit represented by the following general formula (3).

In the general formula (3), R ⁶ represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxyl group having 1 to 8 carbon atoms. R ⁶ is preferably a tert-butyl group, an acetoxy group, or a 1-ethoxyethoxy group, and particularly preferably a tert-butyl group. The repeating unit represented by the general formula (3) can be formed by copolymerizing a styrene derivative as a monomer. A preferred styrene derivative used as a monomer at this time is tert-butoxystyrene.

  For the purpose of controlling the hydrophilicity and solubility of the hydroxyl group-containing resin, other monomers can be copolymerized. Specific examples of “other monomers” include (meth) acrylic acid aryl esters, dicarboxylic acid diesters, nitrile group-containing polymerizable compounds, amide bond-containing polymerizable compounds, vinyls, allyls, and chlorine-containing polymerizations. Compound, conjugated diolefin, and the like. More specifically, dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; aryl (meth) acrylates such as phenyl (meth) acrylate and benzyl (meth) acrylate; styrene, α-methylstyrene , M-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene, pt-butoxystyrene and other aromatic vinyls; t-butyl (meth) acrylate, 4,4,4-trifluoro-3 -(Meth) acrylic acid esters such as hydroxy-1-methyl-3-trifluoromethyl-1-butyl (meth) acrylate; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide Bond-containing polymerizable compound; vinyl acetate, etc. Fatty vinyls, vinyl chloride, chlorine-containing polymerizable compounds such as vinylidene chloride; 1,3-butadiene, isoprene, may be used conjugated diolefins such as 1,4-dimethyl butadiene. These monomers can be used individually by 1 type or in combination of 2 or more types.

  Further, specific examples of the “other monomers” include compounds represented by the following general formula (4).

In said general formula (4), R <^7> , R < ⁸ > and R < ⁹ > show a hydrogen atom, a C1-C10 alkyl group, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group mutually independently. . In the general formula (4), A represents a single bond, an oxygen atom, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, and B represents a single bond or a divalent organic group having 1 to 20 carbon atoms. R ²⁰ represents a monovalent organic group.

Among the groups represented by R ⁷ , R ⁸ and R ⁹ in the general formula (4), the alkyl group having 1 to 10 carbon atoms includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, A hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, etc. can be mentioned. Preferred R ⁷ and R ⁸ are hydrogen atoms, and preferred R ⁹ is a hydrogen atom or a methyl group.

In the general formula (4), R ¹⁰ is a monovalent organic group, preferably a monovalent organic group containing a fluorine atom. R ¹⁰ is preferably a fluoroalkyl group having 1 to 20 carbon atoms, and more preferably a fluoroalkyl group having 1 to 4 carbon atoms.

  Specific examples of the fluoroalkyl group having 1 to 20 carbon atoms include a difluoromethyl group, a perfluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl)- 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 (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perf) Olopropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5 -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-dodecafluorohexyl group Perfluoropentylmethyl group, perfluorohexyl group, 2- (perfluoropentyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoroheptyl group , Perfluorohexylmethyl group, perfluoroheptyl Group, 2- (perfluorohexyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6,7,7-tetradecafluorooctyl group, perfluoroheptylmethyl Group, perfluorooctyl group, 2- (perfluoroheptyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8-hexa Decafluorononyl 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 can be mentioned.

  Among the specific examples of the fluoroalkyl group having 1 to 20 carbon atoms, when the fluoroalkyl group has an excessively large carbon number, the solubility in an alkaline aqueous solution tends to be low. For this reason, a perfluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group are preferable among the specific examples of the fluoroalkyl group having 1 to 20 carbon atoms.

  Among the groups represented by B in the general formula (4), examples of the divalent organic group having 1 to 20 carbon atoms include a methylene group; an ethylene group; a 1,3-propylene group and a 1,2-propylene group. Propylene group; tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, penta Decamethylene group, hexadecamethylene group, heptacamethylene 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, methylidene group, Saturated chain hydrocarbon groups such as a tylidene group, a propylidene group and a 2-propylidene group; a cyclobutylene group such as a 1,3-cyclobutylene group; a cyclopentylene group such as a 1,3-cyclopentylene group; 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. And 30 cyclic ring hydrocarbon ring groups such as a hydrocarbon ring group.

  Preferred examples of the “other monomer” represented by the general formula (4) include 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate, 2-(((trifluoromethyl And) sulfonyl) amino) ethyl-1-acrylate and compounds represented by the following formulas (4-1) to (4-6).

  The use ratio of the “other monomer” represented by the general formula (4) is usually 1 to 50 mol%, preferably 2 to 30 mol%, based on all monomers constituting the hydroxyl group-containing resin. More preferably, it is 2 to 20 mol%.

(Alcohol solvent)
The alcohol solvent contained in the insolubilized resin composition contains alcohol. This alcohol solvent should be used as long as it can sufficiently dissolve the hydroxyl group-containing resin and the crosslinking component contained as necessary and does not dissolve the first resist pattern formed with the first resist agent. Can do. As the alcohol contained in the alcohol solvent having such properties, a monohydric alcohol having 1 to 8 carbon atoms is preferable. More specifically, 1-propanol, isopropanol, 1-butanol, 2-butanol, tert-butanol, 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-pen Tanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 1-heptanol 2-heptanol, 2-methyl-2-heptanol, 2-methyl-3-heptanol and the like. 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 (water content relative to the total solvent) is preferably 10% by mass or less, and more preferably 3% by mass or less. When the water content of the alcohol solvent exceeds 10% by mass, the solubility of the hydroxyl group-containing resin tends to decrease. The alcohol solvent is particularly preferably a non-aqueous solvent containing alcohol (an anhydrous alcohol solvent substantially free of water).

(Other solvents)
In the insolubilized resin composition, “other solvents” other than the alcohol solvent described above can be mixed for the purpose of adjusting the coating property when applied onto the first resist pattern. As the “other solvent”, a solvent that does not erode the first resist pattern and that uniformly applies the insolubilized resin composition can be used.

  Specific examples of “other solvents” 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 Alkyl ethers of polyhydric alcohols such as dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether Alkyl ether acetates of polyhydric alcohols such as teracetate and propylene glycol monomethyl ether acetate; aromatic hydrocarbons such as toluene and xylene; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2- Ketones such as pentanone and diacetone alcohol; ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, hydroxy Ethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate An ester such as ethyl acetate or butyl acetate, and water or the like. Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates ketones, esters, and water are preferred.

  The blending ratio of “other solvent” is usually 30% by mass or less, preferably 20% by mass or less, based on the total solvent. If the blending ratio of “other solvent” exceeds 30% by mass, the first resist pattern may be eroded and problems such as intermixing with the insolubilized resin composition may occur. One resist pattern may be buried. In addition, when mix | blending water as "another solvent", it is preferable that the mixture ratio is 10 mass% or less.

(Crosslinking component)
The insolubilized resin composition preferably contains a crosslinking component as necessary. This crosslinking component is a compound having a group represented by the following general formula (5) (hereinafter also referred to as “crosslinking component I”) or a compound having two or more cyclic ethers as a reactive group (hereinafter referred to as “crosslinking component”). II ”) is preferred. The crosslinking component preferably includes both the crosslinking component I and the crosslinking component II.

In the general formula (5), R ¹¹ and R ¹² represent a hydrogen atom or a group represented by the following general formula (6). However, at least one of R ¹¹ and R ¹² is a group represented by the following formula (6).

In the general formula (6), R ¹³ and R ¹⁴ are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or a carbon number 2 in which R ¹³ and R ¹⁴ are connected to each other. 10 represents a ring of from 10 to 10, and R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. This crosslinking component reacts with the hydroxyl group-containing resin by the action of an acid and / or reacts with the crosslinking component to cure the hydroxyl group-containing resin.

  Specific examples of the crosslinking component I include compounds having a functional group such as an imino group, a methylol group, or a methoxymethyl group in the molecule. More specifically, alkylation is performed by alkylating all or part of active methylol groups such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea, etc. A nitrogen-containing compound as ether can be mentioned. Examples of the alkyl group include a methyl group, an ethyl group, a butyl group, or a mixture thereof. The nitrogen-containing compound may contain an oligomer component partially self-condensed. Specific examples of the nitrogen-containing compound include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril and the like.

Of the specific examples of the crosslinking component I, commercially available compounds include the following trade names: Cymel 300, 301, 303, 350, 232, 235, 236, 238, 266, 267, 285, 1123, 1123-10, 1170, 370, 771, 772, 172, 1172, 325, 327, 703, 712, 254, 253, 212, 1128, 701, 202, 207 (Nippon Cytec Co., Ltd.), Nicarak MW-30M, 30, 22, 24X, Nicarak MS-21, 11, 001, Nicarax MX-002, 730, 750, 708, 708, 706, 042, 035, 45, 410, 302, 202, Nicarak SM-651, 652, 653 551, 451, Nicarak SB-401, 355, 303, 301, 255, 203, 201, Nicarax BX-4000, 37, 55H, Nicarac BL-60 (Sanwa Chemical) For example). Among them, Cymel 325, 327, 703, 712, 254, R ¹ and R ^{2 in} the general formula (1) correspond to a compound containing a hydrogen atom, that is, an imino group. 253, 212, 1128, 701, 202, and 207 are preferable.

  Specific examples of the crosslinking component II include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy). Cyclohexane-meta-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 modification , 4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3 An epoxycyclohexyl group-containing compound such as 1,4-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 ethers, ethylene glycol, propylene group Call, polyglycidyl ethers of polyether polyols obtained by adding an aliphatic polyhydric one or more alkylene oxides to an alcohol such as glycerin; diglycidyl esters of aliphatic long chain dibasic acid;

  Monoglycidyl ethers of aliphatic higher alcohols; monoglycidyl ethers of polyether alcohols obtained by adding phenol, cresol, butylphenol, or alkylene oxide thereto; glycidyl esters of higher fatty acids;

  3,7-bis (3-oxetanyl) -5-oxa-nonane, 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, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether, triethyleneglycolbis (3-ethyl-3 -Oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, Licyclodecanediyldimethylene (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, di Ntaerythritol 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- Examples thereof include oxetane compounds having two or more oxetane rings in the molecule, such as ethyl-3-oxetanylmethyl) ether and EO-modified bisphenol F (3-ethyl-3-oxetanylmethyl) ether.

  Commercially available products of the crosslinking component II are molecules such as Aron Oxetane OXT-101, 121, 221 (above, manufactured by Toagosei Co., Ltd.), OXTP, OXBP, OXIPA (above, manufactured by Ube Industries, Ltd.) under the trade names below. Examples thereof include oxetane compounds having two or more oxetane rings.

  Among these, 1,6-hexanediol diglycidyl ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, and OXIPA are preferable. In addition, these crosslinking components (2) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The amount of the crosslinking component contained in the insolubilized resin composition is preferably 1 to 100 parts by mass and more preferably 5 to 70 parts by mass with respect to 100 parts by mass of the hydroxyl group-containing resin. If it is less than 1 part by mass, curing will be insufficient and the resist pattern will tend not to shrink. On the other hand, if it exceeds 100 parts by mass, curing may proceed excessively and the resist pattern may be buried.

  Moreover, it is preferable that the total content rate of hydroxyl-containing resin and a crosslinking component is 0.1-30 mass% with respect to the whole insolubilization resin composition containing a non-aqueous solvent and alcohol solvent, and 1-20. More preferably, it is mass%. When the total content ratio of the hydroxyl group-containing resin and the crosslinking component is less than 0.1% by mass, the coating film becomes too thin, and the pattern edge portion may be cut off. On the other hand, if it exceeds 30% by mass, the viscosity becomes too high, and it may be difficult to embed in a fine pattern.

(Surfactant)
If necessary, a surfactant may be added to the insolubilized resin composition for the purpose of improving the applicability, antifoaming property, leveling property and the like of the insolubilized resin composition. Specific examples of surfactants that can be blended are as follows: BM-1000, BM-1100 (above, manufactured by BM Chemie); MegaFuck F142D, F172, F173, F183 (above, large) Nippon Ink Chemical Co., Ltd.); Fluorad FC-135, FC-170C, FC-430, FC-431 (above, manufactured by Sumitomo 3M); Surflon S-112, S-113, S-131, Fluorine series such as S-141, S-145 (made by Asahi Glass Co., Ltd.); SH-28PA, -190, -193, SZ-6032, SF-8428 (made by Toray Dow Corning Silicone Co., Ltd.) Mention may be made of surfactants. In addition, the compounding quantity of these surfactants becomes like this. Preferably it is 5 mass parts or less with respect to 100 mass parts of hydroxyl-containing resin.

(Positive radiation sensitive resin composition)
Both the “first resist agent” and the “second resist agent” are soluble in an alkali developer by the dissociation of acid dissociable groups contained therein by the action of an acid generated from the acid generator upon exposure. The exposed portion of the resist having a high value is dissolved and removed by an alkali developer, and a positive resist pattern can be obtained.

  The second resist agent (positive radiation-sensitive resin composition of the present invention) contains a resin having a repeating unit represented by the following general formula (1) (hereinafter also referred to as “resin agent resin”). It is. In addition, it is preferable that the 1st resist agent also contains resin for resist agents like the 2nd resist agent.

In the general formula (1), R ¹ represents hydrogen or a methyl group, and a plurality of R ² are independently of each other a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, Or a C1-C4 linear or branched alkyl group is shown. (I) at least one of R ² is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof; or (ii) any two R ² are bonded to each other. And a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing carbon atoms to which each is bonded, and the remaining R ² is a straight chain having 1 to 4 carbon atoms Alternatively, it is a branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof.

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

In the general formula (1), specific examples of the derivative of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ² include a hydroxyl group; a carboxyl group; an oxo group (that is, a ═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-cyanopropyl group 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 hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, and a cyanomethyl group are preferable.

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

Specific examples of the group represented by “—C (R ² ) ₃ ” in the general formula (1) include groups represented by the following general formulas (1a) to (1f).

In the general formulas (1a) to (1f), R ¹⁶ is independently 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 (1), a portion represented by “—COOC (R ² ) 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 resist agent resin itself is a resin that is insoluble in alkali or hardly soluble in alkali, but is resin that becomes alkali-soluble by the action of an acid. Here, “alkali insoluble or hardly soluble in alkali” 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 (1). In the case where a film made of only the resin containing the repeating unit represented by the general formula (1) is processed (but not exposed), 50% or more of the initial film thickness 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.

  The polystyrene-reduced weight average molecular weight Mw measured by gel permeation chromatography (GPC) of the resist agent resin is usually 1,000 to 500,000, preferably 1,000 to 100,000, and more preferably 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. Moreover, it is preferable that ratio (Mw / Mn) of Mw of resin for resist agents and the polystyrene conversion number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 1-5, More preferably. In addition, it is preferable that the ratio of the low molecular weight component which has a monomer as a main component contained in resin for resist agents 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).

(Acid generator)
The positive radiation sensitive resin composition preferably contains an acid generator having a structure represented by the following general formula (7), which is decomposed by exposure.

In the general formula (7), R ¹⁹ is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched group having 1 to 10 carbon atoms. Or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms. R ¹⁷ 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.

In the general formula (7), R ¹⁸ are 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. May be a naphthyl group, or two R ¹⁸ 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: RC _n F _2n SO ₃ ⁻ (wherein R is a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms. N is an integer of 1 to 10), and q is an integer of 0 to 10.

In the general formula (7), examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ¹⁷ , R ¹⁸ , and R ¹⁹ include a methyl group, an ethyl group, and 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 (7), examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms represented by R ¹⁷ and R ¹⁸ include a methoxy group, an ethoxy group, an n-propoxy group, i- Propoxy 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- An octyloxy 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 (7), examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms represented by R ¹⁹ 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 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 (7), examples of the linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms represented by R ¹⁷ include a methanesulfonyl group, an ethanesulfonyl group, and n-propanesulfonyl. Group, n-butanesulfonyl group, tert-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 (7), examples of the optionally substituted phenyl group represented by R ¹⁸ 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 Examples thereof include linear, branched, or cyclic alkoxyl groups 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 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. And a linear, branched, or cyclic alkoxyalkyl group. 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, etc., having 2 to 21 carbon atoms, such as linear, branched, or cyclic alkoxycarbonyl groups.

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 (7), the optionally substituted phenyl group represented by R ¹⁸ includes phenyl group, 4-cyclohexylphenyl group, 4-t-butylphenyl group, 4-methoxyphenyl group, 4-t -A butoxyphenyl group and the like are preferable.

In the general formula (7), examples of the optionally substituted naphthyl group represented by R ¹⁸ 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; substituted with a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms One or more of these naphthyl groups or alkyl-substituted naphthyl groups in at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Examples include substituted groups. 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 (7), the optionally substituted naphthyl group represented by R ¹⁸ 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 (7), the divalent group having 2 to 10 carbon atoms formed by bonding two R ¹⁸ to each other is a 5-membered or 6-membered group together with the sulfur atom in the general formula (7). Groups that form a ring, preferably a 5-membered ring (ie, a tetrahydrothiophene ring) are desirable. Examples of the substituent that may be introduced into 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, and an alkoxycarbonyloxy group. Can be mentioned. Incidentally, Examples R ¹⁸ in the general formula (7), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, 1-naphthyl group, tetrahydrothiophene two R ¹⁸ 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 (7), triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-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 Methylnaphthyl) 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) tetrahi B thiophenium cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) can be exemplified tetrahydrothiophenium cation, or the like.

In the general formula (7), the “C _n F _2n —” group in the anion represented by X ⁻ (general formula: RC _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 hydrocarbon group having 1 to 12 carbon atoms represented by R is preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, or a bridged alicyclic hydrocarbon group. Specifically, 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.

  Preferred anion sites in the general formula (7) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hept-2- Yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, and the like.

  Said acid generator can be used individually by 1 type or in combination of 2 or more types. It is also possible to use “other acid generators” other than the above acid generators. Specific examples of “other acid generators” include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds.

  Examples of the onium salt compounds 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 trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

  Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. 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 diazoketone 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 (7) 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 (7) and “other acid generator”. Is usually 80% by mass or less, preferably 60% by mass or less.

  The total content of the acid generator contained in the positive radiation-sensitive resin composition is 0.1 to 100 parts by mass of the resist resin from the viewpoint of ensuring the sensitivity and developability as a resist agent. It is preferably 20 parts by mass, and more preferably 0.5 to 10 parts by mass. When the total content of the acid generator is less than 0.1 parts by mass, the sensitivity and developability of the positive radiation-sensitive resin composition tend to be lowered. On the other hand, if it exceeds 20 parts by mass, the transparency to radiation is lowered, and it tends to be difficult to form a rectangular resist pattern.

(Acid diffusion control agent)
The positive radiation sensitive resin composition 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. This photodegradable base is an onium salt compound that is decomposed by exposure and exhibits acid diffusion controllability.

(Nitrogen-containing organic compounds)
Examples of the nitrogen-containing organic compound include a compound represented by the following general formula (8) (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 (8), R ²⁰ independently of each other represents a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group, a substituted or unsubstituted aryl group, or a substituted or non-substituted group. A substituted 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-tert-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, N -Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonylpyrrolidine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide 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, Gin, 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 generates a base that decomposes upon exposure and exhibits acid diffusion controllability. Specific examples of such an onium salt compound include a sulfonium salt compound represented by the following general formula (9) and an iodonium salt compound represented by the following general formula (10).

In the general formulas (9) and (10), R ^{21 to} R ²⁵ each independently represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. Z ⁻ represents OH ⁻ , R—COO ⁻ , R—SO ₃ ^— (wherein R represents an alkyl group, an aryl group, or an alkaryl group), or an anion represented by the following formula (11). Show.

  Specific examples of the sulfonium salt compound and the iodonium salt compound include triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium acetate, Diphenyl-4-hydroxyphenylsulfonium salicylate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium salicylate, 4-t-butyl Enyl-4-hydroxyphenyliodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyliodonium acetate, 4-t-butylphenyl-4-hydroxyphenyliodonium salicylate, bis (4-t-butylphenyl) iodonium Examples thereof include 10-camphor sulfonate, diphenyliodonium 10-camphor sulfonate, triphenylsulfonium 10-camphor sulfonate, and 4-t-butoxyphenyl diphenylsulfonium 10-camphor sulfonate.

  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 resist resin. 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.

(solvent)
The positive radiation-sensitive resin composition is preferably one obtained by dissolving a resin for a resist agent, an acid generator, an acid diffusion controller and the like 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)”). In addition, a solvent other than the solvent (1) (hereinafter, also referred to as “other solvent”) can be used. Furthermore, the solvent (1) and other solvents can be used in combination.

  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, Linear or 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 singly 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, more preferably 25% by mass or less, based on the total amount of the solvent. It is. The amount of the solvent contained in the positive radiation sensitive resin composition is such that the concentration of the total solid content contained in the positive radiation sensitive resin composition is usually 2 to 70% by mass, preferably 4 to 25%. The amount is such that the mass%, more preferably 4 to 10 mass%.

  The positive-type radiation-sensitive resin composition is prepared by dissolving each component in a solvent so that the total solid content concentration is in the numerical value range described above to obtain a uniform solution, and then filtering with a filter having a pore size of about 0.02 μm, for example. It can prepare by doing.

  Various additives, such as surfactant, a sensitizer, and an aliphatic additive, can be mix | blended with a positive radiation sensitive resin composition as needed.

  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.), F-top 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 singly 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 for resist agents.

  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 for resist agents.

  Examples of the alicyclic additive that can be added to the positive radiation sensitive resin composition include an alicyclic additive having an acid dissociable group, an alicyclic additive having no acid dissociable group, and the like. Can do. 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 [4.4.0.12,5.17,10] A dodecane etc. can be mentioned.

  These alicyclic additives can be used singly 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 for resist agents, Preferably it is 30 mass parts or less. When the compounding amount of the alicyclic additive is more than 50 parts by mass with respect to 100 parts by mass of the resist resin, the heat resistance as a resist tends to be lowered. 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.

  [Mw and Mn]: Using a GPC column manufactured by Tosoh Corporation (trade name “G2000HXL”, trade name “G3000HXL”, trade name “G4000HXL”), flow rate: 1.0 mL / min, elution Measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of solvent: tetrahydrofuran, column temperature: 40 ° C. Further, the degree of dispersion “Mw / Mn” was calculated from the measurement results of Mw and Mn.

  [Remaining ratio of low molecular weight components]: Using a trade name “Inersil ODS-25 μm column” (4.6 mmφ × 250 mm) manufactured by GL Sciences Inc., flow rate: 1.0 mL / min, elution solvent: acrylonitrile / 0.1 It was measured by high performance liquid chromatography (HPLC) under the analysis conditions of a% phosphoric acid aqueous solution. In addition, a low molecular weight component is a component which has a monomer as a main component, More specifically, it is a component below the molecular weight of a molecular weight below 1000, Preferably it is a component below the molecular weight of a trimer.

^[13 C-NMR analysis]: ¹³ C-NMR analysis of the respective polymers, using a JEOL Co., Ltd. under the trade name "JNM-EX270", was performed using CDCl ₃ as solvent for measurement.

(Synthesis Example 1: Polymer (A-1))
53.93 g (50 mol%) of the compound represented by the following formula (m-1), 10.69 g (10 mol%) of the compound represented by the following formula (m-2), and the following formula (m-3) A monomer solution was prepared by dissolving 35.38 g (40 mol%) of the compound represented by formula (2) in 200 g of 2-butanone and further adding 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate). did. A 1000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes, then heated to 80 ° C. with stirring, and the monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured 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 on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (A-1) (74 g, yield 74). %). Moreover, as a result of ¹³ C-NMR analysis, it has a repeating unit represented by the following formula (A-1), and the content ratio (molar ratio) of each repeating unit is a / b / c = 53.0 / The polymer was 9.8 / 37.2, Mw / Mn: 1.70, Mw: 6900, and the residual ratio of the low molecular weight component: 0.03% by mass.

<Polymer (A-1)>
Copolymerization ratio (molar ratio): a / b / c = 53.0 / 9.8 / 37.2, Mw / Mn: 1.70, Mw: 6900, remaining ratio of low molecular weight component: 0.03 mass%

(Synthesis Examples 2 to 8: Polymers (A-1) to (A-5))
A polymer having repeating units represented by the following formulas (A-2) to (A-5) in the same manner as in Synthesis Example 1 except that different monomers are used in each combination ( A-2) to (A-5) were synthesized.

<Polymer (A-2)>
Copolymerization ratio (molar ratio): a / b / c = 50/37/13, Mw / Mn: 1.62, Mw: 5200, residual ratio of low molecular weight component = 0.03 mass%

<Polymer (A-3)>
Copolymerization ratio (molar ratio): a / b / c = 53.6 / 9.8 / 36.6, Mw / Mn: 69, Mw: 8100, residual ratio of low molecular weight component: 0.04% by mass

<Polymer (A-4)>
Copolymerization ratio (molar ratio): a / b / c = 40.4 / 15.5 / 45.1, Mw / Mn: 1.73, Mw: 6100, remaining ratio of low molecular weight component: 0.08% by mass

<Polymer (A-5)>
Copolymerization ratio (molar ratio): a / b / c = 50.0 / 36.9 / 13.1, Mw / Mn: 1.78, Mw: 8200, remaining ratio of low molecular weight component: 0.03 mass%

(Preparation of positive resist)
Using the synthesized polymers (A-1) to (A-5), the acid generator (D), the acid diffusion controller (E), and the solvent (F), the formulation shown in Tables 1 and 2 First resist agents (1) to (7) and second resist agents (8) to (12) were prepared according to the above.

<Acid generator (D)>
(D-1): 4-Nonafluoro-n-butylsulfonyloxyphenyl diphenylsulfonium nonafluoro-n-butanesulfonate (D-2): Triphenylsulfonium nonafluoro-n-butanesulfonate (D-3): Triphenyl Sulfonium 2- (bicyclo [2.2.1] hept-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)>
(E-1): (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol Nt-butoxycarbonylpyrrolidine (E-2): triphenylsulfonium salicylate (E-3 ): Triphenylsulfonium 10-camphorsulfonate

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

(Synthesis Example 6: Polymer (B-1))
As starting materials, 62.13 g of p-hydroxymethacrylanilide (M-1), 37.87 g of pt-butoxystyrene (M-2) and 10.21 g of azobisisobutyronitrile were used. (IPA) It melt | dissolved in 300g, and the polymerization reaction was performed on the recirculation | reflux conditions (82 degreeC) for 6 hours. After cooling the reaction vessel with running water, 200 g of ethyl acetate, 140 g of IPA, and 140 g of methanol were added to homogenize, and 600 g of water was further added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 = 55.4 / 44.6 (molar ratio), polymer (B-1) having an Mw of 6500 and Mw / Mn of 1.58 (yield 70%) Got. The structures of p-hydroxymethacrylanilide (M-1) and pt-butoxystyrene (M-2) are shown below.

(Synthesis Example 7: Polymer (B-2))
As starting materials, 17.62 g of p-hydroxymethacrylanilide (M-1), 10.22 g of p-tert-butoxystyrene (M-2), 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate 2.16 g of (M-3) and 2.18 g of azobisisobutyronitrile were dissolved in 90 g of isopropanol (IPA), and a polymerization reaction was performed for 6 hours under reflux conditions (82 ° C.). After cooling the reaction vessel with running water, 60 g of ethyl acetate, 42 g of IPA, and 42 g of methanol were added and homogenized, and 180 g of water was further added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-3 = 54.2 / 41.3 / 4.5 (molar ratio), polymer having Mw of 8400, and Mw / Mn of 1.56 (B- 2) (yield 77%) was obtained. The structure of 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate (M-3) is shown below.

(Synthesis Example 8: Polymer (B-3))
As starting materials, p-hydroxymethacrylanilide (M-1) 25.34 g, 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate (M-3) 18.68 g, MOI-BP (M- 4) 5.99 g and 3.13 g of azobisisobutyronitrile were dissolved in 150 g of isopropanol (IPA), and a polymerization reaction was performed under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-3 / M-4 = 54.5 / 36.0 / 9.5 (molar ratio), Mw of 8000, and polymer having Mw / Mn of 1.55 (B- 3) (Yield 30 g, yield 60%) was obtained. The structure of MOI-BP (M-4) is shown below.

(Synthesis Example 9: Polymer (B-4))
As starting materials, p-hydroxymethacrylanilide (M-1) 26.41 g, p-tert-butoxystyrene (M-2) 4.38 g, 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate (M-3) 12.98 g, MOI-BP (M-4) 6.24 g, and azobisisobutyronitrile 3.26 g were dissolved in isopropanol (IPA) 150 g, and the mixture was refluxed at 82 ° C. A time polymerization reaction was carried out. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-3 / M-4 = 54.2 / 14.5 / 18.5 / 12.8 (molar ratio), Mw is 7800, and Mw / Mn is 1. 53 (yield 34 g, yield 68%) was obtained.

(Synthesis Example 10: Polymer (B-5))
As starting materials, p-hydroxymethacrylanilide (M-1) 24.95 g, p-tert-butoxystyrene (M-2) 17.37 g, 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate 3.68 g of (M-3), 4.00 g of glycidyl methacrylate (M-6), and 3.70 g of azobisisobutyronitrile are dissolved in 150 g of isopropanol (IPA), and the mixture is refluxed (82 ° C.) for 6 hours. A polymerization reaction was performed. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-3 / M-6 = 45.2 / 40.5 / 4.5 / 9.8 (molar ratio), Mw was 8200, and Mw / Mn was 1. A polymer (B-5) 61 (yield 34 g, yield 70%) was obtained. The structure of GMA (M-6) is shown below.

(Synthesis Example 11: Polymer (B-6))
As starting materials 25.56 g of p-hydroxymethacrylanilide (M-1), 20.34 g of p-tert-butoxystyrene (M-2), 4.10 g of glycidyl methacrylate (M-6), and azobisisobutyronitrile 3.79 g was dissolved in 150 g of isopropanol (IPA), and a polymerization reaction was performed under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-6 = 45.5 / 45.5 / 4.5 / 9.0 (molar ratio), Mw is 8000, and Mw / Mn is 1.62. A union (B-6) (35 g yield, 70% yield) was obtained.

(Synthesis Example 12: Polymer (B-7))
30.66 g of p-hydroxymethacrylanilide (M-1), 15.25 g of p-tert-butoxystyrene (M-2), 4.10 g of glycidyl methacrylate (M-6), and azobisisobutyronitrile as starting materials 3.70 g was dissolved in 150 g of isopropanol (IPA), and a polymerization reaction was performed under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-6 = 55.2 / 35.5 / 4.5 / 9.3 (molar ratio), Mw is 8200, and Mw / Mn is 1.55. A union (B-7) (yield 34 g, yield 68%) was obtained.

(Synthesis Example 13: Polymer (B-8))
As starting materials, 29.73 g of p-hydroxymethacrylanilide (M-1), 14.78 g of p-tert-butoxystyrene (M-2), 5.49 g of CYMM100 (M-7), and azobisisobutyronitrile 3 .67 g was dissolved in 150 g of isopropanol (IPA), and a polymerization reaction was carried out for 6 hours under reflux conditions (82 ° C.). After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-7 = 55.1 / 35.6 / 9.3 (molar ratio), Mw of 8000, and Mw / Mn of 1.52 (B- 8) (yield 30 g, yield 60%) was obtained. The structure of CYMM100 (M-7) is shown below.

(Synthesis Example 14: Polymer (B-9))
As starting materials, 29.93 g of p-hydroxymethacrylanilide (M-1), 14.88 g of p-tert-butoxystyrene (M-2), 5.19 g of OXMA (M-8), and azobisisobutyronitrile 3 .70 g was dissolved in 150 g of isopropanol (IPA), and a polymerization reaction was performed under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-8 = 55.2 / 35.5 / 9.3 (molar ratio), polymer having Mw of 7800, and Mw / Mn of 1.55 (B- 9) (30 g yield, 60% yield) was obtained. The structure of OXMA (M-8) is shown below.

(Synthesis Example 15: Polymer (B-10))
As starting materials, p-hydroxymethacrylanilide (M-1) 26.55 g, p-tert-butoxystyrene (M-2) 4.40 g, 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate (M-3) 13.05 g, MOI-BM (M-5) 6.00 g, and azobisisobutyronitrile 3.28 g were dissolved in isopropanol (IPA) 150 g, and the mixture was refluxed at 82 ° C. A time polymerization reaction was carried out. After cooling the reaction vessel with running water, 100 g of ethyl acetate, 70 g of IPA, and 70 g of methanol were added and homogenized, and further 300 g of water was added and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. As a result, M-1 / M-2 / M-3 / M-5 = 55.2 / 12.8 / 20.8 / 11.2 (molar ratio), Mw was 8000, and Mw / Mn was 1. Polymer (B-10) No. 56 (yield 30 g, yield 60%) was obtained. The structure of MOI-BM (M-5) is shown below.

(Preparation of insolubilized resin composition)
Using the synthesized polymers (B-1) to (B-10), the crosslinking agent (C) and the solvent (F) were added to these in accordance with the formulation shown in Table 3, and the mixture was stirred for 3 hours. Insolubilized resin compositions (A) to (M) were prepared by filtration using a 03 μm filter.

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

<Solvent (F)>
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. After spin-coating the first resist agent (1) using the trade name “CLEAN TRACK ACT12”, the coating film has a film thickness of 150 nm by PB (115 ° C., 60 seconds) and cooling (23 ° C., 30 seconds). Formed. Next, using an ArF immersion exposure apparatus (trade name “XT1250i”, manufactured by ASML), exposure is performed through a mask under optical conditions of NA: 0.85, Outer / Inner = 0.89 / 0.59 Annular. did. After PEB (115 ° C., 60 seconds) and cooling (23 ° C., 30 seconds) on a hot plate of the trade name “CLEAN TRACK ACT12”, a 2.38 mass% TMAH aqueous solution was developed with the LD nozzle of the developing cup. The paddle was developed (30 seconds) 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.

  On the first resist pattern of the obtained substrate for evaluation A, the insolubilized resin composition (A) was spin-coated using a trade name “CLEAN TRACK ACT12” and applied to a film thickness of 150 nm. PB before development (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 performing paddle development (60 seconds) with a 2.38 mass% TMAH aqueous solution as a developer using the LD nozzle of the developing cup, Rinse with ultrapure water. Spin-drying was performed by shaking off at 2000 rpm for 15 seconds. After development, PB (165 ° C., 90 seconds) was performed to obtain an evaluation substrate B on which an insolubilized resist pattern was formed.

(Reference Examples 2 to 20)
Each of the first resist agent and the insolubilized resin composition shown in Table 4 was used, and a film was formed under the conditions shown in Table 4 (For Reference Examples 13, 15, 17 and 19, instead of PB before development, As for Reference Examples 12, 18 and 20, an insolubilized resist pattern was formed in the same manner as in Reference Example 1 except that Xe ₂ lamp irradiation treatment was performed in place of PB after development. Evaluation substrate B was obtained.

Example 1
On the insolubilized resist pattern of the evaluation substrate B obtained in Reference Example 1, the second resist agent (8) was spin-coated using a trade name “CLEAN TRACK ACT12”, PB (130 ° C., 60 seconds), cooling (23 ° C., 30 seconds) to form a coating film having a thickness of 150 nm. Using an ArF immersion exposure apparatus, exposure was performed through a mask under optical conditions of NA: 0.85 and Outer / Inner = 0.89 / 0.59 Annular. In the exposure, as shown in FIG. 4, a region corresponding to the upper surface of the first line portion 1a and a region having a predetermined width (20 nm) from the side surface of the first line portion 1a in the second resist layer 12 are formed. The exposed area was designated as the non-exposed area. After PEB (95 ° C., 60 seconds) and cooling (23 ° C., 30 seconds) on a hot plate of the trade name “CLEAN TRACK ACT12”, a 2.38 mass% TMAH aqueous solution was developed with the LD nozzle of the developing cup. The paddle was developed (30 seconds) 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.

(Examples 2 to 15)
The same as in Example 1 except that the evaluation substrate B and the second resist agent (or first resist agent) shown in Table 5 were used, respectively, and the film was formed under the conditions shown in Table 5. Thus, an evaluation substrate C on which a second resist pattern was formed was obtained.

(Comparative Examples 1-3)
In the case of Example 1 described above, except that the substrate (evaluation substrate A) not treated with the insolubilized resin composition shown in Table 5 was used, and the second resist pattern was formed under the conditions shown in Table 5. In the same manner as described above, an evaluation substrate C was obtained.

(Pattern evaluation)
Using a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi Keiki Co., Ltd.), the resist patterns formed on the evaluation substrates A to C were evaluated according to the following criteria.

<Evaluation board A>
The presence or absence of resist pattern formation was confirmed.

<Evaluation board B>
The presence or absence of resist pattern formation was confirmed, and the case where the first resist pattern remained was evaluated as “◯”, and the case where the first resist pattern disappeared was evaluated as “x”. The evaluation results are shown in Table 4.

<Evaluation substrate C>
When the second space portion 1b (width = 20 ± 5 nm) as shown in FIGS. 5 and 6 is additionally formed, “o”, (i) the first resist pattern disappears, (ii) the second resist No pattern was formed, or (iii) Even when the second resist pattern was formed, the case where the first resist pattern remained undissolved was evaluated as “x”. The evaluation results are shown in Table 5.

  According to the resist pattern forming method of the present invention, the pattern gap of the resist pattern can be effectively miniaturized and a pattern exceeding the wavelength limit can be formed favorably and economically. For this reason, the resist pattern forming method of the present invention can be very suitably employed in the field of microfabrication represented by the manufacture of integrated circuit elements that are expected to become increasingly finer in the future.

It is sectional drawing which shows an example of a 1st resist pattern typically. It is sectional drawing which shows an example of an insolubilized resist pattern typically. It is a top view which shows an example of an insolubilized resist pattern typically. It is sectional drawing which shows typically the state which exposes a 2nd resist layer. It is sectional drawing which shows an example of a 2nd resist pattern typically. It is a top view which shows typically an example of a 2nd resist pattern.

Explanation of symbols

1: first resist pattern, 1a: first line portion, 1b: first space portion, 2: second resist pattern, 2a: second line portion, 2b: second space portion, 3: insolubilized resist pattern, 5: Insoluble film, 10: Substrate, 12: Second resist layer, W ₁ : Width of first space part, W ₂ : Width of second space part

Claims (2)

(1) On the first resist pattern, a resist pattern insolubilized resin composition containing a hydroxyl group-containing resin and an alcohol solvent is applied, developed after baking or UV curing, and the first resist pattern is developed. A step of forming an insolubilized resist pattern having a plurality of first line portions and a plurality of first space portions insoluble in the developer and the positive radiation sensitive resin composition;
(2) using the positive radiation sensitive resin composition, forming a resist layer at least in the first space part, and selectively exposing the formed resist layer through a mask;
(3) Develop and form a second line portion in the first space portion, and form the first line portion, the second line portion, and the first line portion and the second line portion. And forming a second resist pattern having one or more second space portions whose width (W ₂ ) exceeds 0% of the width (W ₁ ) of the first space portion and is 30% or less. Process,
A resist pattern forming method comprising: (1) On the first resist pattern, a resist pattern insolubilized resin composition containing a hydroxyl group-containing resin and an alcohol solvent is applied, developed after baking or UV curing, and the first resist pattern is developed. A step of forming an insolubilized resist pattern having a plurality of first line portions and a plurality of first space portions insoluble in the developer and the positive radiation sensitive resin composition;
(2) using the positive radiation sensitive resin composition, forming a resist layer at least in the first space part, and selectively exposing the formed resist layer through a mask;
(3) Develop and form a second line portion in the first space portion, and form the first line portion, the second line portion, and the first line portion and the second line portion. Forming a second resist pattern having a second space portion whose width (W ₂ ) is 0 to 30% of the width (W ₁ ) of the first space portion;
Used in the step (2) of the resist pattern forming method having
A positive radiation sensitive resin composition containing a resin having a repeating unit represented by the following general formula (1).

(In the general formula (1), R ¹ represents hydrogen or a methyl group, and a plurality of R ² are independently of each other 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, and (i) at least one of R ² is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof. Or (ii) a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing any two R ^{2 s} bonded to each other and each having a bonded carbon atom. And the remaining R ² is a linear or branched alkyl group having 1 to 4 carbon atoms, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof)

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