JP2011081041A - Resist pattern coating agent and resist pattern formation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist pattern coating agent which can suppress top loss of a resist patten, improving LWR, and achieving insolubilization of the resist pattern to improve curing property of the resist pattern. <P>SOLUTION: The resist pattern coating agent includes a resin having a hydroxyl group, and a solvent containing at least either of a compound represented by general formula (1): R<SP>1</SP>-O-R<SP>2</SP>or a compound represented by general formula (2): R<SP>3</SP>-OH. A total content ratio of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 10 mass% or more in 100 mass% of the solvent. In the general formula (1), each of R<SP>1</SP>and R<SP>2</SP>is a 3C-10C alkyl group or the like which may be replaced with fluorine. In the general formula (2), R<SP>3</SP>is a 1C-5C alkyl group or the like which may be replaced with fluorine. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resist pattern coating agent and a resist pattern forming method, and more specifically, to suppress the top loss of the first resist pattern and improve the curability of the resist pattern when insolubilizing the first resist pattern. The present invention relates to a resist pattern coating agent capable of forming a resist pattern, and a resist pattern forming method capable of easily and efficiently forming a finer resist pattern.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, lithography technology capable of microfabrication at a level of 0.10 μm or less is required.

  In the future, finer pattern formation (for example, a fine resist pattern having a line width of about 45 nm) will be required. In order to achieve such finer pattern formation is to increase the short wavelength of the light source of the exposure apparatus as described above (ArF excimer laser (wavelength 193 nm)) and the numerical aperture (NA) of the lens Can be considered. However, in order to shorten the light source wavelength, a new expensive exposure apparatus is required. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

  In recent years, a liquid immersion lithography (liquid immersion lithography) method has been disclosed as a lithography technique that can solve such problems (for example, Patent Document 1).

  However, it is said to progress even 45nm half pitch of the foregoing exposure technology (hp) is a limit, it has been carried out further technical development for the 32nmhp generations requiring a finer patterning. In recent years, in accordance with the demand for higher complexity and higher density of such devices, a technique for patterning 32 nm LS by overlapping half-cycles of sparse line patterns or isolated trench patterns such as double patterning or double exposure has been proposed. (For example, Non-Patent Document 1).

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

JP-A-10-303114

SPIE 2006 Vol. 6153 6153K

  However, as proposed in Non-Patent Document 1, although there are proposals for several processes, the actual and practical methods and materials have not been developed yet.

  The present invention has been made to solve the above-described problems of the prior art, suppresses the top loss of the resist pattern, improves LWR (low line width roughness), and insolubilizes the resist pattern. It aims at providing the resist pattern coating agent which can improve the sclerosis | hardenability of a resist pattern by this. It is another object of the present invention to provide a resist pattern forming method capable of easily and efficiently forming a finer resist pattern.

  The present invention provides the following resist pattern coating agent and resist pattern forming method.

[1] A resin having a hydroxyl group and a solvent containing at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), wherein the general formula (1) ) And a resist pattern coating agent (hereinafter simply referred to as “coating agent”) in which the total content of the compound represented by the general formula (2) is 10% by mass or more in 100% by mass of the solvent. ").
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)

[2] The resist pattern coating agent according to [1], wherein the resin is obtained by polymerizing a monomer component containing at least one of hydroxyacrylanilide and hydroxymethacrylanilide.

[3] In the compound represented by the general formula (1), R ¹ and R ² in the general formula (1) are each independently a compound having a branched alkyl group having 3 to 10 carbon atoms. The resist pattern coating agent according to [1] or [2].

[4] Step (1) of forming a first resist pattern using the first radiation-sensitive resin composition, and applying a resist pattern coating agent on the formed first resist pattern After UV curing, washing is performed to obtain an insolubilized resist pattern insoluble in the second radiation-sensitive resin composition (2), and on the substrate on which the obtained insolubilized resist pattern is formed, the first Steps (3) for forming a second resist pattern using a second radiation-sensitive resin composition, and [1] to [3] used as the resist pattern coating agent used in a resist pattern forming method ] The resist pattern coating agent in any one of.

[5] Step (1) of forming a first resist pattern using the first radiation-sensitive resin composition, and applying a resist pattern coating agent on the formed first resist pattern, After UV curing, washing is performed to obtain an insolubilized resist pattern insoluble in the second radiation-sensitive resin composition (2), and on the substrate on which the obtained insolubilized resist pattern is formed, the first A step (3) of forming a second resist pattern using a second radiation-sensitive resin composition, wherein the resist pattern coating agent is represented by a resin having a hydroxyl group and the following general formula (1): And a solvent containing at least one of the compound represented by the following general formula (2), and the compound represented by the general formula (1) and the general formula (2) That the total content of the compounds, the solvent in 100% by mass, the resist pattern forming method using the resist pattern coating agent is 10 mass% or more.
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)

  The resist pattern coating agent of the present invention has the effect of reducing the top loss of the formed resist pattern, improving the LWR, and improving the curability of the resist pattern.

  The resist pattern forming method of the present invention has an effect that a finer resist pattern can be satisfactorily formed.

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 an example of the state which formed the 2nd resist layer on the insolubilization resist pattern. It is a top view which shows typically an example of the state which formed the line part of the 2nd resist pattern in the space part of the insolubilized resist pattern. It is a top view which shows typically the other example of the state which formed the line part of the 2nd resist pattern in the space part of the insolubilized resist pattern. It is a top view which shows typically the other example of the state which formed the line part of the 2nd resist pattern on the line part of the insolubilized resist pattern. It is a side view of the state which formed the line part of the 2nd resist pattern on the line part of the insolubilized resist pattern shown in FIG.

  Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to the following embodiment. That is, it is understood that modifications and improvements as appropriate to the following embodiments are also within the scope of the present invention based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.

[1] Resist pattern coating agent:
The resist pattern coating agent of the present invention is represented by a hydroxyl group-containing resin (hereinafter sometimes simply referred to as “resin”), a compound represented by the above general formula (1), and the above general formula (2). A solvent containing at least one of the compounds (hereinafter may be referred to as “solvent for coating agent”), and a compound represented by the general formula (1) and a compound represented by the general formula (2) The total content of is 10% by mass or more in 100% by mass of the solvent. With such a configuration, it is possible to suppress the top loss of the resist pattern, improve the LWR, and improve the curability of the resist pattern by insolubilizing the resist pattern.

[1-1] Resin having a hydroxyl group:
The resin having a hydroxyl group is not particularly limited as long as it has a hydroxyl group in its molecular structure. By using such a resin, the resin and the crosslinking agent described later are crosslinked, and the resist pattern coating agent of the present invention. Exhibits the above effects.

  The resin having a hydroxyl group is a resin obtained by polymerizing a monomer component containing at least one of hydroxyacrylanilide and hydroxymethacrylanilide (hereinafter sometimes referred to as “hydroxy (meth) acrylanilide”). Is preferred. When such a resin is used, it is possible to satisfactorily suppress the top loss of the resist pattern, further improve LWR, and further improve the curability of the resist pattern by insolubilizing the resist pattern.

  Specific examples of hydroxy (meth) acrylanilide include compounds represented by the following general formula (3).

（一般式（３）中、Ｒ^４は、相互に独立に、水素原子、またはメチル基を示し、Ｒ^５は、単結合、または直鎖状、分岐状若しくは環状の２価の炭化水素基を示す。）

(In the general formula (3), R ⁴ independently represents a hydrogen atom or a methyl group, and R ⁵ represents a single bond or a linear, branched or cyclic divalent hydrocarbon group. Show.)

Of the groups represented by R ⁴ in the general formula (3), specific examples of the linear, branched or cyclic divalent hydrocarbon group include a methylene group, an ethylene group, a propylene group (1,3 -Propylene group, 1,2-propylene group), tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group Group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, icosalen group, 1-methyl-1,3-propylene group, 2-methyl- 1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4- Chain hydrocarbon groups such as butylene group, ethylidene group, 1-propylidene group and 2-propylidene group; cyclobutylene groups such as 1,3-cyclobutylene group and cyclopentylene groups such as 1,3-cyclopentylene group A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms such as a cyclohexylene group such as 1,4-cyclohexylene group and a cyclooctylene group such as 1,5-cyclooctylene group. 2 to 4 ring carbons including norbornylene groups such as 1,4-norbornylene group and 2,5-norbornylene group, and adamantylene groups such as 1,5-adamantylene group and 2,6-adamantylene group; Examples include a crosslinked cyclic hydrocarbon ring group such as a hydrocarbon ring group of 4 to 30.

  The content ratio of hydroxy (meth) acrylanilide is preferably 30 to 95 mol%, more preferably 40 to 90 mol%, in 100 mol% of the monomer component. In the above range, further the top loss of the resist pattern is satisfactorily suppressed, with improved particularly the LWR, the resist pattern coating agent particularly can improve the curability of the resist pattern by insolubilizing the resist pattern Obtainable. When the content is less than 30 mol%, the curability is deteriorated and the first resist pattern may be lost during the formation of the second resist pattern. On the other hand, if it exceeds 95 mol%, it becomes difficult to control the curability, so that there is a possibility that the fluctuation of the line width becomes large.

  The monomer component is at least one of a monomer represented by the following general formula (4-1) and a monomer represented by the general formula (4-2) in addition to hydroxy (meth) acrylanilide ( Hereinafter, it may preferably further include “sometimes referred to as“ monomer (i) ””. By including the monomer (i), the number of sites that react with the cross-linking agent to be described later increases, so that the curability of the first resist pattern is improved.

In General Formula (4-1), R ⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, A represents a methylene group, an ethylene group, or a propylene group, and R ⁷ represents the following general formula ( The group represented by 5-1) or the group represented by the following general formula (5-2) is shown. In General Formula (4-2), R ⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, R ⁸ represents a methylene group or an alkylene group having 2 to 6 carbon atoms, and R ⁹ represents A hydrogen atom, a methyl group or an ethyl group is shown, and n is 0 or 1.

（一般式（５−１）及び（５−２）中、Ｒ^１０は、相互に独立して、水素原子または１〜１０の直鎖状、分岐状のアルキル基を示す。）

(In general formulas (5-1) and (5-2), R ¹⁰ independently represents a hydrogen atom or a linear or branched alkyl group of 1 to 10).

  As the monomer (i), specifically, glycidyl methacrylate, glycidyl acrylate, (1-ethyl-1-oxetanyl) methyl methacrylate (trade name “OXMA” manufactured by Ube Industries, Ltd.), 2-[(3, 5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate (Showa Denko, trade name “MOI-BP”), 2- [0- (1-methylpropylideneamino) carbonylamino] ethyl methacrylate (Showa Denko, product Name "MOI-BM").

  The content of the monomer (i) is in monomer component 100 mol%, is preferably 5 to 60 mol%, more preferably from 5 to 50 mol%, particularly preferably 5 to 40 mol% . When the content ratio is less than 5 mol%, the curability is deteriorated, and the first resist pattern may be lost when the second resist pattern is formed. On the other hand, if it exceeds 60 mol%, it becomes difficult to control the curability, so that there is a risk that the line width variation becomes large.

  Furthermore, the monomer component preferably contains a monomer represented by the following general formula (6) (hereinafter may be referred to as “monomer (ii)”). By containing monomer (ii), there exists an advantage that the solubility with respect to the solvent for coating agents of resin improves.

（一般式（６）中、Ｒ^１１は、水素原子、炭素数１〜８の直鎖状若しくは分岐状のアルキル基、または炭素数１〜８の直鎖状若しくは分岐状のアルコキシル基を示す。）

(In General Formula (6), R ¹¹ 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. )

In general formula (6), the group represented by R ¹¹ is preferably a tert-butoxy group, an acetoxy group, or a 1-ethoxyethoxy group, and particularly preferably a tert-butoxy group.

  The content ratio of the monomer (ii) is preferably 5 to 65 mol%, more preferably 10 to 50 mol%, in 100 mol% of the monomer component. When the content ratio is less than 5 mol%, the solubility of the resin in the solvent for the coating agent may decrease. On the other hand, if it exceeds 65 mol%, the solubility of the resin in an alkaline developer is lowered, so that undissolved material may be generated.

  Furthermore, the monomer component, a monomer having an alcoholic hydroxyl group (hereinafter may be referred to as "monomer (iii)"), a monomer having a hydroxyl group derived from an organic acid such as a carboxylic acid (hereinafter At least selected from the group consisting of monomers having a phenolic hydroxyl group (hereinafter sometimes referred to as “monomer (v)”) It is preferable to include one kind of monomer (hereinafter sometimes referred to as “other monomer”). The monomer (v) does not include hydroxy (meth) acrylanilide.

  The monomer (iii), for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, glycerol monomethacrylate And hydroxyalkyl (meth) acrylates. Among these, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferable. In addition, these monomers (iii) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content ratio of the monomer (iii) is preferably 5 to 65 mol% and more preferably 10 to 60 mol% in 100 mol% of the monomer component.

  Examples of the monomer (iv) include acrylic acid, methacrylic acid, crotonic acid, 2-succinoloylethyl (meth) acrylate, 2-malenoylethyl (meth) acrylate, 2-hexahydrophthaloylethyl ( Monocarboxylic acids such as (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate, monohydroxyethyl acrylate phthalate, acrylic acid dimer, 2-hydroxy-3-phenoxypropyl acrylate, t-butoxy methacrylate, t-butyl acrylate; Examples thereof include (meth) acrylic acid derivatives having a carboxyl group, including dicarboxylic acids such as acid, fumaric acid, citraconic acid, mesaconic acid and itaconic acid. Among these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloylethyl methacrylate are preferable. In addition, these monomers (iv) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content ratio of the monomer (iv) is preferably 5 to 65 mol%, more preferably 10 to 60 mol%, in 100 mol% of the monomer component.

  A commercially available product may be used as the monomer (iv). Specifically, as a commercial product of ω-carboxy-polycaprolactone monoacrylate, for example, trade name “Aronix M-5300” manufactured by Toagosei Co., Ltd. may be mentioned. Moreover, as a commercial item of acrylic acid dimer, the brand name "Aronix M-5600" by Toagosei Co., Ltd. is mentioned, for example. Furthermore, as a commercial item of 2-hydroxy-3-phenoxypropyl acrylate, for example, trade name “Aronix M-5700” manufactured by Toagosei Co., Ltd. may be mentioned.

  Examples of the monomer (v) include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, α-methyl-p-hydroxystyrene, α-methyl-m-hydroxystyrene, α-methyl-o-. hydroxystyrene, 2-allylphenol, 4-allylphenol, 2-allyl-6-methylphenol, 2-allyl-6-methoxyphenol, 4-allyl-2-methoxyphenol, 4-allyl-2,6-dimethoxy phenol 4-allyloxy-2-hydroxybenzophenone and the like. Among these, p-hydroxystyrene and α-methyl-p-hydroxystyrene are preferable.

  The content of the monomer (v) are, in monomer component 100 mol%, is preferably 5～65Mol%, more preferably from 5 to 50 mol%, particularly preferably 5～45Mol% .

  The ratio of the total amount of at least one monomer selected from the group consisting of monomer (iii), monomer (iv), and monomer (v), that is, use of other monomers If the ratio is too small, there are too few reaction sites with the crosslinking agent described later, and there is a risk that the resist pattern will not easily shrink. On the other hand, if the use ratio is too large, the resist pattern may be buried due to swelling during development. That is, if is outside the range proportion of other monomers described above, respectively, to control the line width variation of the insolubilized resist pattern formed by using the insolubilizing resin composition may become difficult.

  The monomer component may further contain another monomer (hereinafter, may be referred to as “another monomer” in some cases) for the purpose of controlling its hydrophilicity and solubility.

  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 polymerizable compounds. And conjugated diolefins.

  Specifically, dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; (meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; t-butyl (meth) acrylate , 4,4,4-trifluoro-3-hydroxy-1-methyl-3-trifluoromethyl-1-butyl (meth) acrylate and other (meth) acrylic acid esters; acrylonitrile, methacrylonitrile and other nitrile groups Polymerizable compounds; Amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; Fatty acid vinyls such as vinyl acetate; Chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; 1,3-butadiene, isoprene, 1,4- Conjugated diolefins such as dimethylbutadiene It can gel. In addition, these other monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

  Furthermore, as another monomer, the compound represented by following General formula (7) is preferable.

（一般式（７）中、Ｒ^１２〜Ｒ^１４は、相互に独立に、水素原子、炭素数１〜１０のアルキル基、ヒドロキシメチル基、トリフルオロメチル基、またはフェニル基を示し、Ｒ^１５は、１価の有機基を示し、Ｒ^１６は、単結合、または炭素数１〜２０の２価の有機基を示し、Ｂは、単結合、酸素原子、カルボニル基、カルボニルオキシ基、またはオキシカルボニル基を示す。）

(In General Formula (7), R ^{12 to} R ¹⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group, and R ¹⁵ represents Represents a monovalent organic group, R ¹⁶ represents a single bond or a divalent organic group having 1 to 20 carbon atoms, and B represents a single bond, an oxygen atom, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group. Group.)

Among the groups represented by R ^{12 to} R ¹⁴ in the general formula (7), specific examples of the alkyl group having 1 to 10 carbon atoms include, for example, a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like. In the general formula (7), the groups represented by R ^{12 to} R ¹⁴ are such that the groups represented by R ¹² and R ¹³ are hydrogen atoms, and the group represented by R ¹⁴ is a hydrogen atom or a methyl group. It is preferable that

In general formula (7), the monovalent organic group represented by R ¹⁵ is preferably a monovalent organic group containing a fluorine atom, and more preferably a C 1-20 fluoroalkyl group. Particularly preferred is a fluoroalkyl group having 1 to 4 carbon atoms. If the carbon number of the fluoroalkyl group is too large, the solubility in an aqueous alkali solution tends to be low. Therefore, the fluoroalkyl group is preferably a perfluoromethyl group, a perfluoroethyl group, or a perfluoropropyl group.

  Examples of the compound represented by the general formula (7) include 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate and 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-acrylate. The compounds represented by the following formulas (7-1) to (7-6) are preferred.

  Furthermore the content of other monomers in the monomer component 100 mol%, is preferably 1 to 50 mol%, more preferably from from 2 to 30 mol%, particularly preferably 2～20Mol% .

[1-1-1] Method for preparing resin having hydroxyl group:
The resin having a hydroxyl group is, for example, the above monomer component in the presence of a radical polymerization initiator (optionally a chain transfer agent) such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. And can be prepared by polymerization in a suitable solvent.

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

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

  Resins having a hydroxyl group, have high purity and no toxicity, i.e., in addition to the content of impurities such as halogens or metals is small, the monomer component or oligomer component remaining following default value (for example, HPLC (high performance liquid chromatography It is preferable that it is 0.1% by mass or less) by the analysis by chromatography). When an insolubilized resin composition containing a resin having a high purity hydroxyl group is used, process stability can be improved and the resist pattern shape can be further refined.

  Examples of a method for purifying a resin having a hydroxyl group include the following methods. As a method for removing impurities such as metals, a method of adsorbing metals in a polymerization solution using a zeta potential filter, or a metal solution in a chelate state by washing the polymerization solution with an acidic aqueous solution such as oxalic acid or sulfonic acid. The method of removing etc. can be mentioned. In addition, as a method of reducing the residual monomer component and oligomer component to a specified value or less, a liquid-liquid extraction method that removes the residual monomer component and oligomer component by combining water washing and an appropriate solvent, a specific method A purification method in a solution state such as ultrafiltration that extracts and removes only components having a molecular weight or less, and a monomer remaining by coagulating a resin having a hydroxyl group in the poor solvent by dropping the polymerization solution into the poor solvent Examples thereof include a reprecipitation method for removing components and the like, a purification method in a solid state such as washing a resin having a hydroxyl group separated by filtration with a slurry poor solvent, and the like. Note that these methods may be combined.

[1-1-2] Physical property values:
The weight average molecular weight in terms of polystyrene (hereinafter sometimes referred to as “Mw”) measured by gel permeation chromatography (GPC) of the hydroxyl group-containing resin is preferably 1,000 to 500,000. More preferably, it is 1,000-50,000, and it is especially preferable that it is 1,000-20,000. If the Mw is less than 1,000, it may be difficult to form a uniform coating film after coating. On the other hand, if it exceeds 500,000, it may be difficult to remove with a developer after thermosetting.

[1-2] Solvent:
As a solvent contained in the resist pattern coating agent, a solvent containing at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2) is contained. The total content of the compound represented by (1) and the compound represented by the general formula (2) is 10% by mass or more in 100% by mass of the solvent.
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)

  By using such a solvent (coating agent solvent), the hydroxyl group-containing resin and the crosslinking agent contained as necessary are sufficiently dissolved. Therefore, a solvent for the coating agent for hard to occur the first radiation-sensitive resin composition and intermixing, the loss of the first resist pattern (i.e., the first resist pattern will melt. Particularly Top Ross ( The surface portion of the first resist pattern is melted))). Furthermore, by using the solvent for a coating agent, the LWR of the first resist pattern can be improved, the curability of the resist pattern can be improved, and the resistance to the second radiation-sensitive composition can be obtained.

In the general formula (1), examples of the linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine represented by R ¹ and R ² include a methyl group, an ethyl group, and a propyl group. Group, butyl group, pentyl group, isoamyl group and the like.

Examples of the group (group) in which R ¹ and R ² are bonded to each other to form a cyclic structure include 3 to 10 carbon atoms forming the cyclic structure, such as oxetane, tetrahydrofuran, furan, and tetrahydropyran. Can be mentioned.

  Specific examples of the compound represented by the general formula (1) include dibutyl ether, sec-butyl ether, tert-butyl ether, diisoamyl ether, dipentyl ether, dihexyl ether, and the like. "AE-3000" (Asahi Glass Co., Ltd.) etc. can be mentioned. In addition, these may be used individually by 1 type and may be used in combination of 2 or more types.

In the compound represented by the general formula (1), it is preferable that R ¹ and R ² in the general formula (1) are each independently a compound having a branched alkyl group having 3 to 10 carbon atoms. When R ¹ and R ^{2 in} general formula (1) are each independently a branched alkyl group having 3 to 10 carbon atoms, a resin having a hydroxyl group and a crosslinking agent contained as necessary It will be sufficiently dissolved. Therefore, intermixing can be suppressed satisfactorily. In addition, the LWR of the first resist pattern can be further improved, the curability of the first resist pattern can be further improved, and good resistance to the second radiation-sensitive composition can be obtained.

  The content ratio of the compound represented by the general formula (1) is 10 to 90% by mass in the total amount of 100% by mass of the compound represented by the general formula (1) and the compound represented by the general formula (2). It is preferably 15 to 85% by mass, more preferably 20 to 80% by mass. When the content ratio is in the above range, there is an advantage that the storage stability is improved because the solubility in the resin and the crosslinking agent described later is good. And when the said content rate is less than 10 mass%, since the mixing amount of a pattern coating agent and a 1st resist layer increases, there exists a possibility that the loss of a pattern may deteriorate. On the other hand, if it exceeds 90% by mass, the storage stability of the resist pattern coating agent may be deteriorated.

In the general formula (2), as a specific example of the compound having a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine represented by R ³ , a product name manufactured by Daikin “TFP”, product name “OFP”, and the like can be given.

  Specific examples of the compound represented by the general formula (2) include linear alkyl alcohols such as 1-propanol, 1-butanol, 1-pentanol, 1-hexanol; isopropyl alcohol, 2-butanol, tert -Butyl alcohol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, 2-hexanol, 3-hexanol, 2-methyl- 1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 2-heptanol, 2-methyl-2-heptanol, 2-methyl Lu-3-heptanol, 2-ethylhexanol, 2,3-dimethyl-3-heptanol, 3-methyl-3-octanol, 4-methyl-4-octanol, 3,5,5-trimethyl-1-hexanol, 2 , 2-dimethyl-3-octanol, 3,7-dimethyl-3-octanol, 4,7-dimethyl-4-octanol, 4-ethyl-2-octanol, 4-ethyl-3-octanol, 3-methyl-3 -Nonanol, 4-methyl-4-nonanol, 5-methyl-5-nonanol, 4-n-propyl-4-heptanol, 2,4,6-trimethyl-4-heptanol and the like can be mentioned.

  Among these, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, tert-butyl alcohol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 2-methyl-3 -Branched alkyl alcohols such as heptanol are preferred.

  The content ratio of the compound represented by the general formula (2) is 10 to 100% by mass in a total amount of 100% by mass of the compound represented by the general formula (1) and the compound represented by the general formula (2). It is preferably 15 to 95% by mass, more preferably 20 to 90% by mass. When the content ratio is in the above range, there is an advantage that the storage stability is improved because the solubility in the resin and the crosslinking agent described later is good. And when the said content rate is less than 10 mass%, since the solubility of resin and the crosslinking agent mentioned later falls, there exists a possibility that the storage stability of a resist pattern coating agent may deteriorate.

  The total content of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 10% by mass or more and 10 to 60% by mass in 100% by mass of the solvent. Preferably, it is 15-50 mass%. When the content ratio is less than 10% by mass, the hydroxyl group-containing resin and the crosslinking agent contained as necessary are not sufficiently dissolved. Further, since the intermixing with the first resist pattern is increased, the resist pattern is lost (that is, the surface portion of the first resist pattern is melted).

  The use ratio of the solvent for the coating agent is preferably 80% by mass or more, more preferably 90% by mass or more, in 100% by mass of the resist pattern coating agent. There exists a possibility that it may become difficult to form a uniform coating film after application | coating as the said usage rate is less than 80 mass%.

  Further, the water content in the solvent for the coating agent is preferably 10% by mass or less, more preferably 3% by mass or less, and a non-aqueous solvent (an anhydrous alcohol solvent substantially free of water). It is particularly preferred. There exists a possibility that the solubility of resin which has a hydroxyl group as the said moisture content exceeds 10 mass% may fall.

  The solvent for the coating agent is not particularly limited as long as it contains at least one of the compound represented by the general formula (1) and the compound represented by the following general formula (2), but at least the general formula (1) It is preferable that the compound represented by general formula (1) and the compound represented by the following general formula (2) are also included.

  The solvent for a coating agent may contain other solvents for the purpose of adjusting coating properties. As the other solvent, a solvent that does not erode the resist pattern and has an effect of uniformly applying the coating agent can be suitably used.

  Examples of other solvents include polyhydric alcohol alkyl ether acetates such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol monomethyl ether acetate; aromatic hydrocarbons such as toluene and xylene. s; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, ketones such as diacetone alcohol, ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, 2-hydroxy-2 -Ethyl methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxypropionic acid Chill, 3-methoxy ethyl propionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl acetate, esters such as ethyl acetate and butyl acetate; etc. can be mentioned water, among these, ketones, esters Water is preferred.

  The content of other solvents is preferably 30% by mass or less, more preferably 20% by mass or less, in 100% by mass of the solvent for coating agents. If the content ratio is more than 30% by mass, the resist pattern may be eroded and problems such as intermixing with the resist pattern coating agent may occur. As a result, the resist pattern may be buried. In addition, when water is included as another solvent, the content is preferably 10% by mass or less.

[1-3] Crosslinking agent:
The resist pattern coating agent of the present invention may further contain a crosslinking agent in addition to the hydroxyl group-containing resin and the coating agent solvent. The cross-linking agent reacts with a resin having a hydroxyl group by the action of an acid to cure the resin having a hydroxyl group.

  The crosslinking agent includes a compound having a group represented by the following general formula (8) (hereinafter sometimes referred to as “crosslinking agent (1)”), or has two or more cyclic ethers as a reactive group. It preferably contains a compound (hereinafter sometimes referred to as “crosslinking agent (2)”). In addition, it is also preferable that a crosslinking agent contains both a crosslinking agent (1) and a crosslinking agent (2).

（一般式（８）中、Ｒ^１７及びＲ^１８は、水素原子、または下記一般式（９）で表される基を示す。但し、Ｒ^１７及びＲ^１８の少なくともいずれかは下記一般式（９）で表される基である。）

(In the general formula (8), R ¹⁷ and R ¹⁸ represent a hydrogen atom or a group represented by the following general formula (9). However, at least one of R ¹⁷ and R ¹⁸ represents the following general formula (9 ).

（一般式（９）中、Ｒ^１９及びＲ^２０は、相互に独立に、水素原子、炭素数１〜６のアルキル基、または炭素数１〜６のアルコキシアルキル基を示すか、或いはＲ^１９及びＲ^２０が相互に結合して形成される炭素数２〜１０の環状構造を示す。Ｒ^２１は、水素原子、または炭素数１〜６のアルキル基を示す。）

(In General Formula (9), R ¹⁹ and R ²⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having 1 to 6 carbon atoms, or R ¹⁹ and R ²⁰ represents a cyclic structure having 2 to 10 carbon atoms formed by bonding to each other, and R ²¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

  Examples of the crosslinking agent (1) include compounds having a functional group such as an imino group, a methylol group, or a methoxymethyl group in the molecule. Specifically, all or part of active methylol groups such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea are alkylated to form alkyl ether And the like.

  Specific examples of the alkyl group include a methyl group, an ethyl group, a butyl group, or a group in which these are mixed. Moreover, as a nitrogen-containing compound, the oligomer component which one part self-condensed may be included. Specific examples include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, and tetrabutoxymethylated glycoluril.

  A commercial item may be sufficient as a crosslinking agent (1). Examples of 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 (above, manufactured by Nippon Cytec Co., Ltd.), Nicarak MW-30M, 30, 22, 22, 24X, Nicarak MS-21, 11, 11, 001, Nicarax MX-002, 730, 750, 708, 706, 042, 035, 45, 410, 302, 202, Nicarak SM-651, 652, 653, 551, 451, Nika SB-401, 355, 303, 301, 255, 203, 201, Nicarax BX-4000, 37, 55H, Nicalac BL-60 (above, Sanwa Chemical Co., Ltd.), Aaron Oxetane OXT-101, 121, 221 (above, manufactured by Toagosei Co., Ltd.), OXTP, OXBP (above, manufactured by Ube Industries, Ltd.), and the like.

Among these, Cymel 325, 327, 703, 712, which corresponds to a compound in which any of R ¹⁴ and R ^{15 in} the general formula (8) has a group having a hydrogen atom (that is, an imino group), 254, 253, 212, 1128, 701, 202, 207 and Nicarax MX-750 are preferred.

  Examples of the crosslinking agent (2) 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), ε-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;

  Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin; diglycidyl esters of aliphatic long-chain dibasic acids; aliphatic Monoglycidyl ethers of higher alcohols; 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, pentaerythritol tetraacrylate, pentaerythritol triacrylate Tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (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, penta Erythritol 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, dipentaerythritoltetrakis (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-oxetanyl) Methyl) ether, ethylene oxide (EO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, propylene oxide (PO) modified bisphenol A bis ( -Ethyl-3-oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO-modified Bisphenol F (3-ethyl-3-oxetanylmethyl) ether and the like can be mentioned.

  The cross-linking agent (2) may be a commercially available product, and the commercially available cross-linking component (2) is a trade name of Aron Oxetane OXT-101, 121, 221 (above, Toagosei Co., Ltd.). And oxetane compounds having two or more oxetane rings in the molecule such as OXTP, OXBP, and OXIPA (above, manufactured by Ube Industries).

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

  The amount of the crosslinking agent used 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 the amount used is less than 1 part by mass, curing may be insufficient and shrinkage of the resist pattern may be difficult to occur. 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 it is 0.1-30 mass% in 100 mass% of coating agents, and, as for the total content rate of resin which has a hydroxyl group, and a crosslinking agent, it is still more preferable that it is 1-20 mass%. If the total content is less than 0.1% by mass, the coating film becomes too thin, and there is a possibility that film breakage may occur at the pattern edge portion. On the other hand, if it exceeds 30% by mass, the viscosity becomes too high and it may be difficult to embed it in a fine pattern.

[1-4] Surfactant:
The resist pattern coating agent of the present invention may further contain a surfactant. The surfactant improves the coating property, defoaming property, leveling property and the like of the coating agent. Specifically, BM-1000, BM-1100 (above, manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (above, manufactured by Dainippon Ink & Chemicals, Inc.) are trade names. , Florard FC-135, FC-170C, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, Fluorine-based surfactants such as S-145 (above, manufactured by Asahi Glass Co., Ltd.), SH-28PA, ibid-190, ibid-193, SZ-6032, SF-8428 (above, produced by Toray Dow Corning Silicone) Can do.

  It is preferable that the usage-amount of surfactant is 5 mass parts or less with respect to 100 mass parts of resin which has a hydroxyl group.

  Further, the resist pattern coating agent of the present invention comprises a step (1) of forming a first resist pattern using the first radiation-sensitive resin composition, and a resist pattern on the formed first resist pattern. Applying the coating agent, baking or UV curing, and washing to obtain an insolubilized resist pattern insoluble in the second radiation-sensitive resin composition (2), and forming the obtained insolubilized resist pattern And (2) forming a second resist pattern using the second radiation-sensitive resin composition on the finished substrate, and used as a resist pattern coating agent used in a resist pattern forming method. It is preferable.

  That is, the resist pattern coating agent of the present invention can suppress the top loss of the resist pattern satisfactorily by using it as a resist pattern coating agent in the resist pattern forming method including the steps (1) to (3) described above. While further improving the LWR, it is possible to further improve the curability of the resist pattern by insolubilizing the resist pattern. In addition, the method similar to the formation method of the resist pattern of this invention mentioned later can be employ | adopted for the resist pattern formation method containing process (1)-(3) mentioned above.

[2] Method for forming resist pattern of the present invention:
The resist pattern forming method of the present invention includes a step (1) of forming a first resist pattern using the first radiation-sensitive resin composition, and a resist pattern coating agent on the formed first resist pattern. (2) to obtain an insolubilized resist pattern that is insoluble in the second radiation-sensitive resin composition, and a substrate on which the obtained insolubilized resist pattern is formed And a step (3) of forming a second resist pattern using the second radiation-sensitive resin composition, and a resin having a hydroxyl group as a resist pattern coating agent, and the following general formula (1) And a solvent containing at least one of the compound represented by the following general formula (2) and the compound represented by the general formula (1) and the general formula (2) The total content of the compound represented by the, in 100% by mass solvent, a method using a resist pattern coating agent is 10 mass% or more.
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)

  By the method including such steps, a finer resist pattern can be formed satisfactorily. That is, a resist pattern composed of the insolubilized resist pattern and the second resist pattern can be satisfactorily formed on the substrate. And if the resist pattern formed in this way is used, a semiconductor can be manufactured suitably.

[2-1] Step (1):
Step (1) is a step of forming a first resist pattern using the first radiation-sensitive resin composition. Specifically, the first radiation-sensitive resin composition (hereinafter referred to as “first radiation-sensitive resin composition”) is formed on the substrate. , A first resist layer formed on the substrate using a selective exposure, and then developing to form a first resist pattern. . FIG. 1 is a cross-sectional view schematically showing a state in which a first resist pattern 1 is formed on a substrate 10.

[2-1-1] Substrate:
As the substrate, a conventionally known silicon wafer, a wafer coated with SiN, an organic antireflection film or the like can be used. 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. 6-12452. It is preferable to keep it.

[2-1-2] First radiation-sensitive resin composition:
A conventionally well-known radiation sensitive resin composition can be used for the 1st radiation sensitive resin composition, and if it can form a resist layer, it can be especially used without a restriction | limiting. That is, in the first radiation-sensitive resin composition, the resist layer formed is dissociated from an acid-dissociable group present in the resin by the action of an acid generated from an acid generator by exposure, and the resist layer is exposed to an alkaline developer. What is necessary is that the solubility becomes high and the exposed portion can be dissolved and removed by an alkali developer to form a resist pattern. Specifically, a resin containing a resin having an acid dissociable group, a radiation sensitive acid generator (hereinafter referred to as “acid generator”), and a resist layer forming solvent can be used. The first resist agent used when forming the first resist layer and the second resist agent used when forming the second resist layer may be the same or different. Also good.

[2-1-3] Formation of first resist pattern:
Specifically, the first resist pattern can be formed as follows. First, a first resist layer is formed on a substrate using the first radiation-sensitive resin composition, and the formed first resist layer is selectively exposed through a predetermined mask pattern. Then, it develops with an alkali developing solution etc. and forms a 1st resist pattern.

  The first resist layer can be formed on the substrate by applying the first resist agent by an appropriate application means such as spin coating, cast coating, roll coating or the like. In addition, after apply | coating a 1st resist agent, you may volatilize the solvent in a coating film by prebaking (henceforth "PB" may be mentioned hereafter) as needed. The heating conditions for PB are appropriately selected depending on the composition of the first resist agent, but are usually 30 to 200 ° C, preferably 50 to 150 ° C.

  The first resist layer is provided with a protective film, for example, as disclosed in JP-A-5-188598 to prevent the influence of basic impurities contained in the environmental atmosphere. Is also preferable.

  The exposure is performed by irradiating the first resist layer with radiation through a mask having a predetermined pattern. Then, an alkali developing portion (portion that has become alkali-soluble) is formed by exposure. The radiation to be irradiated 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. 193 nm) and far ultraviolet rays represented by KrF excimer laser (wavelength 248 nm) are preferred, and far ultraviolet rays by ArF excimer laser (wavelength 193 nm) are particularly preferred.

  The exposure conditions such as the exposure amount are appropriately selected according to the composition of the first resist agent, the type of additive, and the like. Furthermore, in the present invention, it is preferable to perform a heat treatment (hereinafter sometimes referred to as “PEB”) after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the first resist agent can be smoothly advanced. The heating condition of PEB is appropriately selected depending on the composition of the first resist agent, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  Then, by developing the exposed first resist layer with a developer, the alkali developing portion (exposed region of the first resist layer) is dissolved, and as shown in FIG. A first resist pattern 1 having a line width of 1 is formed on the substrate 10. In addition, after developing using alkaline aqueous solution, generally it wash | cleans with water and dries.

  Examples of the developer that can be used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [ 4.3.0] An alkaline aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. When the concentration is more than 10% by mass, the non-exposed part tends to be easily dissolved in the developer.

  An organic solvent can also be added to the alkaline aqueous solution (developer). Examples of organic solvents 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 Alcohols such as i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol and 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; Examples thereof include esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide. In addition, these organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  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. If the addition amount exceeds 100 parts by volume, the developability may be reduced, and the development residue in the exposed area may increase. An appropriate amount of a surfactant or the like can be added to the developer.

[2-2] Step (2):
In the step (2), a resist pattern coating agent is applied on the formed first resist pattern, and after baking or UV curing, it is washed to be an insolubilized resist that is insoluble in the second radiation-sensitive resin composition. This is a process of obtaining a pattern.

The resist pattern coating agent used in this step can be the same as the resist pattern coating agent of the present invention described above. That is, as a resist pattern coating agent, a resin having a hydroxyl group and a solvent containing at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), Use a resist pattern coating agent in which the total content of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 10% by mass or more in 100% by mass of the solvent. Can do.
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)

  And by using the same thing as the resist pattern coating agent of this invention, a finer resist pattern can be formed favorably.

  FIG. 2 is a cross-sectional view schematically showing an example of a state in which the insolubilized resist pattern 3 is formed on the substrate 1. The insolubilized resist pattern 3 is obtained by forming an insoluble film 5 so as to cover the surface of the first resist pattern 1. FIG. 3 is a plan view of the substrate 10 as viewed from above the insolubilized resist pattern 3 shown in FIG.

  The method for applying the coating agent on the first resist pattern is not particularly limited, and for example, an appropriate application method such as spin coating, cast coating, roll coating or the like can be employed.

In this step, after applying the coating agent, baking or UV curing is performed. By performing baking or UV curing, the first resist pattern and the coating agent are reacted to form an insoluble film covering the first resist pattern. Although heating conditions are suitably selected by the compounding composition of a coating agent, they are 30-200 degreeC normally, Preferably it is 50-170 degreeC. On the other hand, in order to perform UV curing, lamps such as Ar ₂ lamp, KrCl lamp, Kr ₂ lamp, XeCl lamp, Xe ₂ lamp (manufactured by Ushio Inc.) can be used.

  After the baking or UV curing, the insolubilized resist pattern 3 in which the insoluble film 5 made of the coating agent is formed on the first resist pattern 1 as shown in FIG. Can be obtained. The insoluble film 5 is insoluble or hardly soluble in the developer and the second resist agent. That is, the insolubilized resist pattern 3 is a pattern in which the pattern shape remains even when the second resist agent is applied and the second resist layer is exposed and developed. Note that after the cleaning, the insolubilized resist pattern 3 may be cured a plurality of times by heat treatment (PEB) or UV curing as necessary.

  Further, the line width of the pattern may slightly change depending on the thickness of the applied coating agent. In addition, you may perform a process (2) in multiple times as needed.

[2-3] Step (3):
Step (3) is a step of forming a second resist pattern using the second radiation-sensitive resin composition on the substrate on which the obtained insolubilized resist pattern is formed. A second resist layer is formed on the insolubilized resist pattern using the second radiation-sensitive resin composition on the substrate on which the insolubilized resist pattern is formed, and the formed second resist layer is selectively used. And then developing to form a second resist pattern.

[2-3-1] Second radiation sensitive resin composition:
A conventionally well-known radiation sensitive resin composition can be used for the 2nd radiation sensitive resin composition, and if it can form a resist layer, it can be especially used without a restriction | limiting. Specifically, a resin containing an acid-dissociable group-containing resin, a radiation sensitive acid generator (acid generator), and a resist layer forming solvent can be used. In addition, the 2nd radiation sensitive resin composition may use the same thing as a 1st radiation sensitive resin composition, and may use a different thing.

[2-3-2] Formation of second resist pattern:
For the formation of the second resist pattern, the same method as the formation of the first resist pattern can be employed. That is, first, a second resist layer is formed on a substrate on which an insolubilized resist pattern is formed using the second radiation-sensitive resin composition. For example, FIG. 4 is a cross-sectional view schematically showing an example of a state in which the second resist layer 12 is formed on the insolubilized resist pattern 3. Thereafter, the formed second resist layer is selectively exposed through a predetermined mask pattern. At this time, a finer resist pattern can be obtained by exposing a position shifted from the first resist pattern by a half cycle. After the exposure, development is performed with an alkali developer or the like to form a second resist pattern.

  In this step, various resist patterns having a characteristic pattern arrangement can be finally formed by appropriately selecting a mask pattern.

  For example, as shown in FIG. 5, when the insolubilized resist pattern 3 having the first line portion 1a and the first space portion 1b is formed, the mask pattern used in the exposure in the step (3) is selected to select the second pattern. The second line portion 2a of the second resist pattern 2 having the line portion 2a and the second space portion 2b can be formed in the first space portion 1b in parallel with the first line portion 1a.

  For example, as shown in FIG. 6, the second line of the second resist pattern 22 having the second line portion 22a and the second space portion 22b is selected by selecting a mask pattern used in the exposure in the step (3). If the portion 22a is formed in a grid pattern in the first space portion 1b, a resist pattern (contact hole pattern) having the contact hole 15 defined by the first line portion 1a and the second line portion 22a of the insolubilized resist pattern is formed. be able to.

  Further, for example, as shown in FIGS. 7 and 8, if the mask pattern used in the exposure in the step (3) is selected, the second resist pattern 32 having the second line portion 32a and the second space portion 32b is selected. The two line portions 32a can be formed on the first line portion 1a so as to intersect the first line portion 1a.

[3] Radiation sensitive resin composition:
As described above, the radiation-sensitive resin composition (first radiation-sensitive resin composition, second radiation-sensitive resin composition) (hereinafter sometimes referred to as “resist agent”) is acid dissociable. A resin containing a group-containing resin, a radiation-sensitive acid generator, and a resist layer forming solvent can be used.

[3-1] Resin having an acid dissociable group:
The resin having an acid dissociable group is preferably a resin having a repeating unit represented by the following general formula (10).

In General Formula (10), R ²² represents a hydrogen atom or a methyl group, and each R ²³ is 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 (provided that at least one of R ²³ is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof) Or a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and a derivative thereof each including a carbon atom to which each two R ²³ are bonded to each other, The remaining R ²³ represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof.

In general formula (10), among the groups represented by R ²³ , a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and any two R ²³ are bonded to each other. Specific examples of the divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms each including the carbon atom to which each is bonded include norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, cyclohexane, Groups composed of alicyclic rings derived from cycloalkanes such as cycloheptane and cyclooctane; groups composed of these alicyclic rings are, for example, methyl group, ethyl group, n-propyl group, i-propyl group , N-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like, substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms And the like can be given. Among these, a group composed of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane and cyclohexane, and a group obtained by substituting these with an alkyl group are preferable.

  Specific examples of the derivative of a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a group consisting of the above alicyclic ring and an alkyl substituent such as a hydroxyl group; a carboxyl group; an oxo group (that is, , = O group); hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl Group, a hydroxyalkyl group having 1 to 4 carbon atoms such as 3-hydroxybutyl group and 4-hydroxybutyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group Group, 1-methylpropoxy group, t-butoxy group and the like C1-C4 alkoxyl group; cyano group; cyanomethyl group, 2-cyanoethyl group 3-cyanopropyl group, and a group obtained by substituting one or more substituents such as a cyano alkyl group having 2 to 5 carbon atoms such as a 4-cyanobutyl group. Among these, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, and a group substituted with a cyanomethyl group are preferable.

  Further, 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, Examples thereof include 1-methylpropyl group and t-butyl group. Among these, a methyl group and an ethyl group are preferable.

In the general formula (10), the moiety represented by “—COOC (R ²³ ) ₃ ” is a moiety that is dissociated by the action of an acid to form a carboxyl group and becomes an alkali-soluble site. This “alkali-soluble site” is a group that becomes an anion by the action of an alkali (ie, alkali-soluble). On the other hand, the “acid-dissociable group” is a group in which an alkali-soluble site is protected with a protecting group, and means a group that is not “alkali-soluble” until the protecting group is dissociated with an acid.

  A resin having an acid-dissociable group is a resin that is itself insoluble in alkali or hardly soluble in alkali, but becomes alkali-soluble by the action of an acid. Here, “alkali insoluble or alkali poorly soluble” is a developing condition for forming a resist pattern using a resist layer made of a resist agent containing a resin having a repeating unit represented by the general formula (10). In the case where a film composed only of a resin having a repeating unit represented by the general formula (10) is processed (but not exposed), 50% or more of the initial film thickness remains after the processing. . On the other hand, “alkali-soluble” refers to the property that 50% or more of the initial film thickness of the film dissolves after the treatment when the same treatment is performed.

  Resins having an acid-dissociable group include monomer components containing a polymerizable unsaturated monomer corresponding to a desired repeating unit, hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, etc. The radical polymerization initiator can be used and polymerized in an appropriate solvent in the presence of a chain transfer agent as necessary.

  Examples of the polymerization solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, Cycloalkanes such as norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide, chlorobenzene; ethyl acetate, n acetate -Saturated carboxylic acid esters such as butyl, i-butyl acetate, methyl propionate; ethers such as tetrahydrofuran, dimethoxyethane, diethoxyethane; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2- Butanol alcohols such as i-butyl alcohol, 1-pentanol, 3-pentanol, 4-methyl-2-pentanol, o-chlorophenol, 2- (1-methylpropyl) phenol; acetone, 2-butanone, 3 Examples thereof include ketones such as -methyl-2-butanone, 4-methyl-2-pentanone, 2-heptanone, cyclopentanone, cyclohexanone, and methylcyclohexanone. These polymerization solvents may be used singly or in combination of two or more.

  Among the polymerization conditions, the reaction temperature is usually 40 to 150 ° C, preferably 50 to 120 ° C. Moreover, reaction time is 1 to 48 hours normally, Preferably it is 1 to 24 hours.

  The Mw of the resin having an acid dissociable group is usually 1,000 to 500,000, preferably 1,000 to 100,000, and more preferably 1,000 to 50,000. If the Mw is less than 1,000, the heat resistance of the resist pattern tends to decrease. On the other hand, if it exceeds 500,000, developability tends to be lowered.

  The ratio (Mw / Mn) between the Mw of the resin having an acid-dissociable group and the number average molecular weight in terms of polystyrene (hereinafter referred to as “Mn”) measured by gel permeation chromatography (GPC) is 1 to 5 is preferable, and 1 to 3 is more preferable.

  A resin having an acid-dissociable group is preferable as the content of impurities such as halogen and metal is smaller because sensitivity, resolution, process stability, pattern profile and the like can be further improved. Examples of purification methods for resins having acid-dissociable groups include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. The method etc. can be mentioned. In addition, it is preferable that the content rate of the low molecular weight component which has a monomer as a main component is 0.1 mass% or less in conversion of solid content in 100 mass% of resin which has an acid dissociable group. The content ratio of the low molecular weight component can be measured, for example, by high performance liquid chromatography (HPLC).

[3-2] Acid generator:
The acid generator generates acid upon exposure. The acid generator preferably includes an acid generator having a structure represented by the following general formula (11). In addition to the acid generator having the structure represented by the general formula (11), other acid generators may be included.

In the general formula (11), R ²⁴ represents a linear or branched alkyl group having 1 to 10 carbon atoms, or an alkoxyl group, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. Indicates a group. Each R ²⁵ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, or a naphthyl group, or two R ^25s are bonded to each other. The C2-C10 bivalent group containing the sulfur cation made is shown. However, the phenyl group, naphthyl group, and divalent group may be substituted. R ²⁶ represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or 2 carbon atoms. -11 linear or branched alkoxycarbonyl group is shown. k represents an integer of 0 to 2, and X ⁻ represents an anion represented by the following general formulas (11-1) to (11-4).

In general formulas (11-1) and (11-2), each R ²⁷ independently represents a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms. In general formula (11-1), q represents an integer of 1 to 10. In general formulas (11-3) and (11-4), each R ²⁸ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms substituted with a fluorine atom, Alternatively, it represents a divalent organic group having 2 to 10 carbon atoms, which is formed by bonding two R ²⁸ to each other and substituted with a fluorine atom. However, the C 2-10 divalent organic group substituted with a fluorine atom may have a substituent other than a fluorine atom.

  In addition, the acid generator which has a structure represented by General formula (11) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the acid generator is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin having an acid dissociable group, from the viewpoint of ensuring sensitivity and developability as a resist agent. More preferably, it is 0.5-10 mass parts. When the content is less than 0.1 part by mass, the sensitivity and developability of the resist agent 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.

  Examples of other acid generators include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds. In addition, another acid generator may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content ratio of the other acid generator is usually 80% by mass or less, preferably 60% by mass or less, in 100% by mass of the total amount of the acid generator.

[3-3] Resist layer forming solvent:
The resist layer forming solvent is capable of dissolving a resin having an acid dissociable group, an acid generator and the like. A uniform coating film can be formed by dissolving in a solvent for forming a resist layer.

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

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

  Moreover, as the solvent for forming the resist layer, a solvent other than the solvent (1) (hereinafter referred to as “other solvent”) can also 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, 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, 2-hydroxy-2-methylpropionic acid ethyl, ethoxyethyl acetate, hydroxyethyl acetate, 2-hydroxy-3-methyl-butyric acid methyl,

  3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-acetate Butyl, 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 monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethyl carbonate , It can be exemplified propylene carbonate.

  Among these, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, and γ-butyrolactone are preferable. In addition, another solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

  When the solvent (1) is used in combination with another solvent, the use ratio of the other solvent is preferably 50% by mass or less, more preferably 30% by mass or less, in 100% by mass of the solvent, and 25% by mass. % Or less is particularly preferable.

[3-4] Acid diffusion controller:
The radiation sensitive resin composition preferably further 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 containing an acid diffusion control agent, the storage stability of the resist agent is improved, the resolution of the resist is further improved, and the resist pattern of the resist pattern due to fluctuations in the holding time (PED) from exposure to post-exposure heat treatment The change in line width can be suppressed, and the process stability can be made extremely excellent.

  The content of the acid diffusion control agent is usually 15 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the resin having an acid dissociable group. . When the content exceeds 15 parts by mass, the sensitivity of the resist agent tends to decrease. If the content 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.

  As the acid diffusion controller, it is preferable to use a nitrogen-containing organic compound or a photodisintegratable base. In addition, an acid diffusion control agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the nitrogen-containing organic compound include a compound represented by the general formula (12) (hereinafter referred to as “nitrogen-containing compound (1)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound”). Compound (2) ”, a polyamino compound having three or more nitrogen atoms in the same molecule and a polymer thereof (hereinafter collectively referred to as“ nitrogen-containing compound (3) ”), an amide group-containing compound, a urea compound, Examples thereof include nitrogen-containing heterocyclic compounds.

（一般式（１２）中、Ｒ^２９は、相互に独立に、水素原子、置換若しくは非置換の直鎖状、分岐状若しくは環状のアルキル基、置換若しくは非置換のアリール基、または置換若しくは非置換のアラルキル基を示す。）

(In the general formula (12), R ²⁹ are each independently a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted group. Represents an aralkyl group of

  Examples of the nitrogen-containing compound (1) include substituted alkyl such as mono (cyclo) alkylamines, di (cyclo) alkylamines, tri (cyclo) alkylamines, and 2,2 ′, 2 ″ -nitrotriethanol. Examples thereof include amines and aromatic amines.

  Examples of the nitrogen-containing compound (2) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl ether. 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, , 4-bis (1- (4-aminophenyl) -1-methylethyl) benzene, 1,3-bis (1- (4-aminophenyl) -1-methylethyl) benzene, bis (2-dimethylaminoethyl) ) Ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imi Zorijinon, 2 quinoxalinium linoleic, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N', N ", N" - can be given pentamethyldiethylenetriamine like.

  Examples of the nitrogen-containing compound (3) include polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, and the like.

  The photodegradable base refers to an onium salt compound that is decomposed by exposure and loses acid diffusion controllability. Specific examples include a sulfonium salt compound represented by the following general formula (13) and an iodonium salt compound represented by the following general formula (14).

R ^{30 to} R ³² in the general formula (13) and R ³³ and R ³⁴ in the general formula (14) each independently represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. Z ⁻ represents OH ⁻ , R ³⁵ —COO ⁻ , R ³⁵ —SO ₃ ^— (wherein R ³⁵ represents an alkyl group, an aryl group, or an alkaryl group), or represented by formula (15). Indicates an anion.

（一般式（１５）中、Ｒ^３６は、フッ素原子で置換若しくは非置換の炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基を示し、ｎは、１または２を示す。）

(In the general formula (15), R ³⁶ is a linear or branched alkyl group having 1 to 12 carbon atoms substituted or unsubstituted with a fluorine atom, or a linear or branched alkyl group having 1 to 12 carbon atoms. Represents an alkoxyl group, and n represents 1 or 2.)

[3-5] Additive:
The radiation-sensitive resin composition can contain various additives such as a surfactant, a sensitizer, and an aliphatic additive.

  Surfactant is a component that has the effect of improving coatability, striation, developability, and the like. For example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octyl Nonionic surfactants such as phenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate; hereinafter referred to as KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (above, manufactured by Tochem Products), Megafax F171, F173 (above, manufactured by Dainippon Ink and Chemicals), Florad FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( As mentioned above, Asahi Glass Co., Ltd.) can be mentioned.

  In addition, these surfactants may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, content of surfactant is 2 mass parts or less normally with respect to 100 mass parts of resin which has an acid dissociable group.

  The sensitizer absorbs radiation energy and transmits the energy to the acid generator, thereby increasing the amount of acid produced, 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.

  In addition, these sensitizers may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, content of a sensitizer is 50 mass parts or less normally with respect to 100 mass parts of resin which has an acid dissociable group.

  An alicyclic additive is a component that exhibits an action of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Examples of such alicyclic additives include alicyclic additives having an acid dissociable group, alicyclic additives having no acid dissociable group, and the like.

More specifically, 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-dimethyl-2,5 -Adamantane derivatives such as di (adamantylcarbonyloxy) hexane; t-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, 2-cyclohexyloxyethyl deoxycholic acid, deoxycholic acid 3-oxosiku Deoxycholic acid esters such as hexyl, deoxycholic acid tetrahydropyranyl, deoxycholic acid mevalonolactone ester; lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyl Lithocholic acid esters such as oxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, adipic acid Alkyl carboxylic acid esters such as di-t-butyl; 3- (2-hydroxy-2,2-bis (trifluoromethyl) ethyl) tetracyclo [6.2.1.1 ^3,6 . ^02.7 ] dodecane and the like.

  In addition, these alicyclic additives may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, content of an alicyclic additive is 50 mass parts or less normally with respect to 100 mass parts of resin which has an acid dissociable group, Preferably it is 30 mass parts or less. When the content is more than 50 parts by mass, the heat resistance as a resist tends to decrease. Furthermore, as additives other than those mentioned above, a dyeing agent or pigment that can visualize the latent image of the exposed area and reduce the influence of halation during exposure, and an adhesive aid that can improve the adhesion to the substrate , Alkali-soluble resins, low-molecular alkali solubility control agents having acid-dissociable protecting groups, antihalation agents, storage stabilizers, antifoaming agents, and the like.

  The radiation-sensitive resin composition is prepared as a coating liquid by, for example, filtering it with a filter having a pore size of about 0.02 μm after dissolving the above-described components in a resist layer forming solvent to form a uniform solution. can do.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example and a comparative example, this invention is not limited to these Examples and a comparative example. In the description of Examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, each measurement and evaluation in each Example and a comparative example were performed in the following way.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]:
Tosoh GPC columns (trade name "G2000HXL", trade name "G3000HXL", trade name "G4000HXL" 1), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature : Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

[Remaining ratio of low molecular weight component (%)]:
Using the trade name “Intersil ODS-25 μm column” (4.6 mmφ × 250 mm) manufactured by GL Sciences, flow rate: 1.0 mL / min, elution solvent: acrylonitrile / 0.1% phosphoric acid aqueous solution, It was measured by high performance liquid chromatography (HPLC). In addition, a low molecular weight component means the component which has a monomer as a main component, and specifically means the component of molecular weight less than 1,000. As a low molecular weight component, it is preferable that it is a component below the molecular weight of a trimer.

[ ¹³ C-NMR analysis]:
The product name “JNM-EX270” manufactured by JEOL Ltd. was used, and analysis was performed using CDCl ₃ as a measurement solvent.

[Evaluation of pattern]:
For the insolubilized resist pattern formed on the evaluation substrate B using a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi Keiki Co., Ltd.), the case where the first resist pattern remains is “ The case where it disappeared was evaluated as “X”. Further, for the second resist pattern formed on the evaluation substrate C, a line-and-space pattern of 50 nm line / 100 nm pitch (50 nm 1 L / 1 S) is formed between the insolubilized resist patterns formed on the evaluation substrate B. The case of additional formation is evaluated as “◯”, and (i) the insolubilized resist pattern disappears, (ii) the second resist pattern is not formed, or (iii) the second resist pattern is formed. Even when the insolubilized resist pattern was undissolved, it was evaluated as “x”.

[Top loss evaluation]:
When the evaluation substrate C was formed, the case where the height of the insolubilized resist pattern was 105 nm or more was evaluated as “◯”, and the case where it was less than 105 nm was evaluated as “x”.

[Evaluation of LWR]:
When the evaluation substrate C was formed, the value of 3σ (3 sigma) of the line width variation measured at 32 points was defined as LWR, and the case where the LWR of the insolubilized resist pattern was less than 5 nm was evaluated as “◯”, and 5 nm The above case was evaluated as “×”.

[Evaluation of pattern curability]:
When the evaluation substrate C is formed, the case where the disappearance of the unexposed portion that has not been exposed when the first resist pattern is formed and the region pattern treated with the insolubilized resin composition is not observed is evaluated as “◯”. The case of disappearance was evaluated as “x”.

(Synthesis Example 1: Polymer (A-1))
In the compound represented by the following formula (L-1) 53.93 g (50 mol%), the compound represented by the following formula (L-2) 10.69 g (10 mol%), and the following formula (L-3) 35.38 g (40 mol%) of the represented compound was dissolved in 200 g of 2-butanone, and 5.58 g of azobisisobutyronitrile (hereinafter referred to as “AIBN”) was further added to prepare a monomer solution. 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 prepared 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 reaction, the polymer solution was cooled to 30 ° C. or less by water cooling, and then poured into 2000 g of methanol, and the precipitated white powder was filtered off. 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 give a white powder polymer (A-1) (having an acid-dissociable group). Resin) (74 g, yield 74%).

Mw of the obtained polymer (A-1) was 6,900, Mw / Mn was 1.70, and the residual ratio of the low molecular weight component was 0.03%. ^Further, 13 C-NMR analysis revealed that a repeating unit represented by the following formula (A-1), the content of each repeating unit (mol ratio), a / b / c = 53.0 / It was 9.8 / 37.2. In addition, this polymer (A-1) is described in Table 1 as resin (A-1) which has an acid dissociable group.

(Synthesis Example 2: Polymer (A-2))
Instead of the compound represented by the formula (L-2), 39.14 g (37 mol%) of the compound represented by the following formula (L-4) was used, and the compound 50 represented by the formula (L-1). Polymer (A-) was prepared in the same manner as in Synthesis Example 1, except that .16 g (50 mol%) was used and 10.70 g (13 mol%) of the compound represented by formula (L-3) was used. 2) (Resin having an acid dissociable group) was obtained (78 g, yield 78%).

Mw of the obtained polymer (A-2) was 5,200, Mw / Mn was 1.62, and the residual ratio of the low molecular weight component was 0.03%. Moreover, it has a repeating unit represented by a following formula (A-2) as a result of < ¹³ > C-NMR analysis, The content rate (mol ratio) of each repeating unit is a / b / c = 50.0 / It was 37.0 / 13.0. In addition, let a polymer (A-2) be resin (A-2) which has an acid dissociable group.

(Synthesis Example 3: Polymer (A-3))
Instead of the compound represented by the formula (L-2), 9.72 g (10 mol%) of the compound represented by the following formula (L-5) was used, and the compound 54 represented by the formula (L-1). Polymer (A-) was prepared in the same manner as in Synthesis Example 1 except that .51 g (50 mol%) was used and 35.76 g (40 mol%) of the compound represented by formula (L-3) was used. 3) was obtained (71 g, 71% yield).

Mw of the obtained polymer (A-3) was 8,100, Mw / Mn was 1.69, and the residual ratio of the low molecular weight component was 0.04%. ^Further, 13 C-NMR analysis revealed that a repeating unit represented by the following formula (A-3), the content of each repeating unit (mol ratio), a / b / c = 53.6 / It was 9.8 / 36.6. In addition, let a polymer (A-3) be resin (A-3) which has an acid dissociable group.

(Synthesis Example 4: Polymer (A-4))
The use of 24.42 g (15 mol%) of the compound represented by the following formula (L-6) in place of the compound represented by the formula (L-2), of the compound represented by the formula (L-3) Instead, 30.40 g (40 mol%) of the compound represented by the following formula (L-7) was used, and 45.18 g (45 mol%) of the compound represented by the formula (L-1) was used. Except for the above, a polymer (A-4) was obtained in the same manner as in Synthesis Example 1 (75 g, yield 75%).

Mw of the obtained polymer (A-4) was 6,100, Mw / Mn was 1.73, and the residual ratio of low molecular weight components was 0.04%. Moreover, it has a repeating unit represented by a following formula (A-4) as a result of < ¹³ > C-NMR analysis, The content rate (mol ratio) of each repeating unit is a / b / c = 44.1 /. It was 15.5 / 40.4. In addition, let a polymer (A-4) be resin (A-4) which has an acid dissociable group.

(Synthesis Example 5: Polymer (A-5))
The use of 35.60 g (35 mol%) of the compound represented by the formula (L-4) instead of the compound represented by the formula (L-2), instead of the compound represented by the formula (L-3) In addition to using 16.17 g (15 mol%) of the compound represented by the following formula (L-8) and 48.23 g (50 mol%) of the compound represented by the formula (L-1). Produced polymer (A-5) in the same manner as in Synthesis Example 1 (72 g, yield 72%).

Mw of the obtained polymer (A-5) was 8,200, Mw / Mn was 1.78, and the residual ratio of low molecular weight components was 0.03%. Moreover, it has a repeating unit represented by a following formula (A-5) as a result of < ¹³ > C-NMR analysis, The content rate (mol ratio) of each repeating unit is a / b / c = 50.0 / It was 36.9 / 13.1. In addition, let a polymer (A-5) be resin (A-5) which has an acid dissociable group.

(Synthesis Example 6: Polymer (A-6))
The use of 28.40 g (35 mol%) of the compound represented by the formula (L-7) instead of the compound represented by the formula (L-2), instead of the compound represented by the formula (L-3) Except that 18.00 g (15 mol%) of the compound represented by formula (L-8) was used and 53.60 g (50 mol%) of the compound represented by formula (L-1) was used. In the same manner as in Synthesis Example 1, a polymer (A-6) was obtained (73 g, yield 73%).

Mw of the obtained polymer (A-6) was 7,100, Mw / Mn was 1.40, and the residual ratio of the low molecular weight component was 0.01%. Moreover, as a result of ¹³ C-NMR analysis, it has a repeating unit represented by the following formula (A-6), and the content (mol ratio) of each repeating unit is a / b / c = 50.0 / It was 35.2 / 14.8. In addition, let a polymer (A-6) be resin (A-6) which has an acid dissociable group.

(Reference Examples 1-14)
(Preparation of resist agent)
Using the polymers (A-1) to (A-6) synthesized in Synthesis Examples 1 to 6, an acid generator, an acid diffusion controller, and a solvent, the resist agents (1) to (1) to the formulation shown in Table 1 are used. (14) was prepared.

  The types of acid generator, acid diffusion controller, and solvent, which are abbreviated in Table 1, are described below.

<Acid generator>
(D-1): 4-Nonafluoro-n-butylsulfonyloxyphenyl diphenylsulfonium nonafluoro-n-butanesulfonate,
(D-2): Triphenylsulfonium nonafluoro-n-butanesulfonate,
(D-3): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate,
(D-4): Triphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1-difluoroethanesulfonate.

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

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

(Synthesis example 7: Resin (B-1) having a hydroxyl group)
62.13 g of p-hydroxymethacrylanilide (compound represented by the following formula (m-1), hereinafter referred to as “compound (m-1)”), pt-butoxystyrene (following formula (m-2) In the following, 37.87 g of a compound represented by the formula (hereinafter referred to as “compound (m-2)”) and 10.21 g of AIBN are dissolved in 300 g of isopropyl alcohol (hereinafter referred to as “IPA”), and reflux conditions (82 ° C.) are obtained. 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 the polymerization solution to make it uniform, and 600 g of water was added thereto and left to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum dried at a temperature of 50 ° C. to obtain a copolymer (B-1) (yield 70%). In addition, Mw of the copolymer (B-1) was 8,500, and Mw / Mn was 2.08. Moreover, as a result of ¹³ C-NMR analysis, the repeating unit derived from (m-1) and the content (mol ratio) of repeating units derived from (m-2) (repetition derived from (m-1)) Unit / repeat unit derived from (m-2)) was 55.4 / 44.6. Let this copolymer (B-1) be resin (B-1) which has a hydroxyl group.

(Synthesis Example 8: Resin having a hydroxyl group (B-2))
17.62 g of compound (m-1), 10.22 g of compound (m-2), 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate (represented by the following formula (m-3) 2.16 g of a compound (hereinafter referred to as “compound (m-3)”) and 2.18 g of AIBN were dissolved in 90 g of IPA, and a polymerization reaction was performed under reflux conditions (82 ° C.) for 6 hours. After cooling the reaction vessel with running water, 60 g of ethyl acetate, 42 g of IPA, and 42 g of methanol were added to the polymerization solution to make it uniform, and 180 g of water was added thereto and allowed to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum dried at a temperature of 50 ° C. to obtain a copolymer (B-2) (yield 77%). In addition, Mw of the copolymer (B-2) was 5,800, and Mw / Mn was 1.50. As a result of ¹³ C-NMR analysis, the content of repeating units derived from the compound (m-1), repeating units derived from the compound (m-2), and repeating units derived from the compound (m-3) (mol) Ratio) (repeating unit derived from compound (m-1) / repeating unit derived from compound (m-2) / repeating unit derived from compound (m-3)) is 54.2 / 41.3 / 4. .5. Let this copolymer (B-2) be resin (B-2) which has a hydroxyl group.

(Synthesis Example 9: Resin (B-3) having a hydroxyl group)
1. 17.8 g of compound (m-1), 10.3 g of compound (m-2), monomer represented by the following formula (m-4) (hereinafter referred to as “compound (m-4)”) 1 g and 2.18 g of AIBN were dissolved in 90 g of 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 to the polymerization solution to make it uniform, and 180 g of water was added thereto and allowed to stand for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum dried at a temperature of 50 ° C. to obtain a copolymer (B-3) (yield 65%). In addition, Mw of the copolymer (B-3) was 7,600, and Mw / Mn was 1.53. Further, as a result of ¹³ C-NMR analysis, the content of repeating units derived from the compound (m-1), repeating units derived from the compound (m-2), and repeating units derived from the compound (m-4) (mol Ratio) (repeating unit derived from compound (m-1) / repeating unit derived from compound (m-2) / repeating unit derived from compound (m-4)) is 60.2 / 35.0 / 4. .8. Let this copolymer (B-3) be resin (B-3) which has a hydroxyl group.

(Synthesis Example 10: Resin having a hydroxyl group (B-4))
3. Compound (m-1) 30.66 g, Compound (m-2) 15.25 g, monomer represented by the following formula (m-5) (hereinafter referred to as “compound (m-5)”) 10 g and 3.70 g of AIBN were dissolved in 150 g of IPA, and a polymerization reaction was performed 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 to the polymerization solution to make a uniform solution, and 300 g of water was further added and left for 1 hour. The viscous polymer that settled in the lower layer was collected and vacuum-dried at 50 ° C. to obtain a polymer (B-4) (yield 68%). In addition, Mw of the obtained polymer (B-4) was 8,200, and Mw / Mn was 1.50. In addition, as a result of ¹³ C-NMR analysis, the content of repeating units derived from the compound (m-1), repeating units derived from the compound (m-2), and repeating units derived from the compound (m-5) (mol Ratio) (repeating unit derived from compound (m-1) / repeating unit derived from compound (m-2) / repeating unit derived from compound (m-5)) is 55.2 / 35.5 / 9. .3. Let this copolymer (B-4) be resin (B-4) which has a hydroxyl group.

Example 1
As shown in Table 2, 100 parts of the hydroxyl group-containing resin (B-1) synthesized in Synthesis Example 7 is used as a crosslinking agent, and the product name “Nicalak MX-750” (manufactured by Nippon Carbide) is used as 30 parts, and as a solvent. A solution in which 1572 parts of 1-butanol and 4-methyl-2-pentanol 1048 are mixed is filtered using a filter having a pore size of 0.03 μm to obtain a resist pattern coating agent (A) (hereinafter referred to as “coating agent”). (A) "may be indicated).

  Next, using the prepared coating agent (A), as described later, after forming a resist pattern in the order of the evaluation substrate A, the evaluation substrate B, and the evaluation substrate C, the resist pattern of the evaluation substrate C The above various evaluations were performed.

  In addition, the kind of the crosslinking agent and solvent which were abbreviated in Table 2 is described below.

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

<Solvent>
F-3: 1-butanol,
F-4: 4-methyl-2-pentanol,
F-5: 3-methyl-1-butanol,
F-6: Dibutyl ether,
F-7: Diisoamyl ether.

(Preparation of evaluation substrate A)
After spin-coating a lower-layer antireflection film (trade name “ARC29A”, manufactured by Brewer Science Co., Ltd.) on a 12-inch silicon wafer (substrate) using a product name “CLEAN TRACK ACT12” (manufactured by Tokyo Electron), A film having a thickness of 77 nm was formed by performing PB (205 ° C., 60 seconds). The resist agent (1) prepared in Reference Example 1 was spin-coated using the trade name “CLEAN TRACK ACT12”, PB (115 ° C., 60 seconds), and then cooled (23 ° C., 30 seconds) to form a film. A coating film having a thickness of 150 nm was formed. Next, using an ArF immersion exposure apparatus (trade name “XT1250i”, manufactured by ASML), NA: 0.85, Outer / Inner = 0.89 / 0.59 Annular optical conditions, 50 nm line / 200 nm pitch The exposure was carried out through a mask having a mask size of. After PEB (115 ° C., 60 seconds) on a hot plate of the trade name “CLEAN TRACK ACT12”, it was cooled (23 ° C., 30 seconds), and 2.38% tetramethylammonium hydroxide was used with the LD nozzle of the developing cup. Paddle development (30 seconds) was performed using the aqueous solution as a developer, and rinsed with ultrapure water. By spin-drying at 2000 rpm for 15 seconds, a substrate for evaluation A having a first resist pattern 1 formed on a wafer (substrate 10) was obtained as shown in FIG.

(Preparation of evaluation substrate B)
After applying the resist pattern coating agent (A) onto the first resist pattern of the obtained evaluation substrate A using the trade name “CLEAN TRACK ACT12” to a film thickness of 150 nm. PB before washing (130 ° C., 60 seconds) was performed. Then, using the product name “CLEAN TRACK ACT12”, cooling with a cooling plate at 23 ° C. for 30 seconds, and then using a LD nozzle of the developing cup with a 2.38% tetramethylammonium hydroxide aqueous solution as a developer for paddle development ( 60 seconds) and rinsed with ultrapure water. Thereafter, spin drying was performed by shaking off at 2000 rpm for 15 seconds, and PB (165 ° C., 90 seconds) after cleaning was performed. As shown in FIG. 2, evaluation was made that the insolubilized resist pattern 3 was formed on the wafer (substrate 10). Substrate B was obtained.

(Creation of evaluation substrate C)
On the insolubilized resist pattern of the obtained evaluation substrate B, the resist agent (9) prepared in Reference Example 9 was spin-coated using a trade name “CLEAN TRACK ACT12” and PB (100 ° C., 60 seconds). Thereafter, it was cooled (23 ° C., 30 seconds) to form a coating film having a thickness of 150 nm. Using an ArF immersion exposure apparatus, the space of the insolubilized resist pattern through a mask having a mask size of 50 nm line / 200 nm pitch under the optical conditions of NA: 0.85 and Outer / Inner = 0.89 / 0.59 Annular The part was exposed. After that, PEB (95 ° C., 60 seconds) on a hot plate of the trade name “CLEAN TRACK ACT12”, then cooled (23 ° C., 30 seconds), and 2.38% tetramethylammonium at the LD nozzle of the developing cup. Paddle development (30 seconds) was performed using a hydroxide aqueous solution as a developer, and rinsed with ultrapure water. Thereafter, by spin-drying by shaking off at 2000 rpm for 15 seconds, an evaluation substrate C on which the second resist pattern 22 was formed in addition to the insolubilized resist pattern 3 was obtained as shown in FIG. Thereafter, the above-described various evaluations were performed on the resist pattern of the obtained evaluation substrate C.

(Examples 2 to 10, Comparative Examples 1 and 2)
Coating agents (B) to (M) were prepared in the same manner as in Example 1 except that the formulation shown in Table 2 was used. Thereafter, using the prepared coating agents (B) to (M), in the same manner as in Example 1, the evaluation substrate A, the evaluation substrate B, and the evaluation substrate C were prepared in this order, and then the evaluation substrate C The above-mentioned various evaluations (pattern evaluation, top loss, LWR, and pattern curability evaluation) were performed on the upper resist pattern.

(Reference Examples 15 to 36)
In order to form a resist pattern and evaluate the resist pattern, an evaluation substrate B was prepared. That is, evaluation was performed in the same manner as in Example 1 except that the resist conditions and resist pattern coating agents shown in Table 3 were used, and the heating conditions (PB and PEB) or UV cure conditions shown in Table 3 were used. A substrate A and an evaluation substrate B were produced in this order.

(Examples 11-32, Comparative Examples 3-5)
Using each resist agent (denoted as “resist agent (second resist agent)” in Table 4) on the insolubilized resist pattern of each of the prepared substrates for evaluation B, A resist pattern was formed on the evaluation substrate C. Thereafter, the above-described various evaluations (pattern evaluation, top loss, LWR, and pattern curability evaluation) were performed on the produced resist pattern on the evaluation substrate C. The evaluation results are shown in Table 4.

  As is apparent from Table 4, by using the resist pattern coating agent of the example, the top loss, LWR, and pattern curability at the time of pattern formation are improved as compared with the case of using the resist pattern coating agent of the comparative example. I was able to confirm. Moreover, according to the resist pattern formation method of an Example, it has confirmed that a finer resist pattern could be favorably formed compared with the resist pattern formation method of a comparative example.

  If the resist pattern coating agent of this invention is used, the fine pattern exceeding a wavelength limit can be formed economically with high precision. 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.

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

Claims (5)

A resin having a hydroxyl group;
A solvent containing at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2),
The resist pattern coating agent whose total content rate of the compound represented by the said General formula (1) and the compound represented by the said General formula (2) is 10 mass% or more in 100 mass% of said solvents.
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)   2. The resist pattern coating agent according to claim 1, wherein the resin is obtained by polymerizing a monomer component containing at least one of hydroxyacrylanilide and hydroxymethacrylanilide. The compound represented by the general formula (1) is a compound in which R ¹ and R ² in the general formula (1) are each independently a branched alkyl group having 3 to 10 carbon atoms. 2. The resist pattern coating agent according to 2. A step (1) of forming a first resist pattern using the first radiation-sensitive resin composition;
A step of applying a resist pattern coating agent on the formed first resist pattern, washing after baking or UV curing, and obtaining an insolubilized resist pattern insoluble in the second radiation-sensitive resin composition ( 2) and
Step (3) of forming a second resist pattern using the second radiation-sensitive resin composition on the obtained substrate on which the insolubilized resist pattern is formed. The resist pattern coating agent according to any one of claims 1 to 3, which is used as the resist pattern coating agent to be used. A step (1) of forming a first resist pattern using the first radiation-sensitive resin composition;
A step of applying a resist pattern coating agent on the formed first resist pattern, washing after baking or UV curing, and obtaining an insolubilized resist pattern insoluble in the second radiation-sensitive resin composition ( 2) and
Forming the second resist pattern on the substrate on which the obtained insolubilized resist pattern is formed using the second radiation-sensitive resin composition, and (3)
As the resist pattern coating agent, a resin having a hydroxyl group, and a solvent containing at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), Resist pattern using a resist pattern coating agent in which the total content of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 10% by mass or more in 100% by mass of the solvent Forming method.
(1) R ¹ —O—R ²
(2) R ³ —OH
(In the general formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 3 to 10 carbon atoms which may be substituted with fluorine, or R 1 ¹ and R ² are combined to form a cyclic structure, wherein R ³ is a linear or branched alkyl group having 1 to 5 carbon atoms which may be substituted with fluorine. Or a monocyclic or polycyclic hydrocarbon group having 3 to 10 carbon atoms.)

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