JP2011059583A - Resin composition for forming fine pattern, method for forming fine pattern and polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for forming a fine pattern which can attain smooth and further stable contraction of a resist pattern by heat treatment, and easy removal thereof by a subsequent alkali aqueous solution treatment. <P>SOLUTION: The resin composition for miniaturization of a resist pattern contains resin, a cross-linking agent for cross-linking the resin and a solvent. The resin includes a repeat unit represented by formula (1-4). In the formula, R<SP>1</SP>represents hydrogen atom, methyl or trifluoromethyl, R<SP>2</SP>represents -CH(CH<SB>3</SB>)-, R<SP>3</SP>represents trifluoromethyl, and R<SP>4</SP>represents hydrogen atom. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fine processing technique using a photoresist, and relates to a resin composition for forming a fine pattern, a method for forming a fine pattern, and a polymer used when the pattern is shrunk by heat treatment after patterning. More specifically, by dissolving a polymer having a repeating unit having a specific structure in a solvent as a resin, a pattern having a diameter of 60 nm or less can be easily covered without entraining bubbles, and the resin for forming a fine pattern Resin composition for fine pattern formation that can use the cup and waste liquid treatment equipment used when applying the lower layer film and photoresist as it is without introducing a new water-based application cup or waste liquid treatment equipment when applying the composition And a polymer that can be used as a resin for a fine pattern forming resin composition and a resin composition for forming a fine pattern.

In recent years, with the progress of miniaturization of semiconductor elements, further miniaturization has been required in the lithography process in the manufacturing method. That is, in the lithography process, microfabrication of 60 nm or less is now required, and a fine pattern is formed using a photoresist material corresponding to short wavelength irradiation light such as ArF excimer laser light and F ₂ excimer laser light. Various methods for forming the film have been studied.
In such a lithography technique, there is an unavoidable limitation in miniaturization due to the limitation of the exposure wavelength, and so far, research has been conducted to enable the formation of a fine pattern exceeding the wavelength limit. I came.

  For example, when a fine resist pattern is formed by thermally shrinking a resist pattern formed using a photoresist, a coating forming agent is provided on the resist pattern, the resist pattern is thermally shrunk by heat treatment, and removed by washing with water. A resist pattern refinement coating forming agent and a method for efficiently forming a fine resist pattern using the resist coating refinement (Patent Document 1) have been proposed. Water-based, insufficient coverage of fine patterns such as contact holes with a diameter of 60 nm or less, and water-based, a dedicated cup is required at the time of coating, resulting in increased costs, and low temperature for transportation, etc. In this case, there is a problem that freezing and precipitation occur.

On the other hand, as a polymer used in the upper layer resin composition for forming an upper layer film that maintains a stable film without eluting into the medium during immersion exposure and is easily dissolved in an alkaline developer, -NH- The repeating unit having a group represented by SO ₂ —Rf (Rf represents a fluorine atom-containing monovalent organic group) in its side chain is contained in an amount of 30 to 100 mol% of the entire repeating unit, and gel permeation A polymer for an immersion upper layer film having a weight average molecular weight of 2,000 to 100,000 measured by a chromatography method is known (Patent Document 2). However, the reaction between this polymer and a crosslinking agent has not been studied, and its application to a resin composition for forming a fine pattern is not known.

JP 2003-195527 A JP 2006-243309 A

  The present invention has been made to cope with such a problem. When a fine pattern is formed by heat-treating a resist pattern formed using a photoresist, the fine-pattern is applied on the resist pattern, and the heat-treatment is performed by heat treatment. The resin composition can be smoothly and stably shrunk, and can be easily removed by subsequent alkaline aqueous solution treatment, and a fine pattern forming method capable of efficiently forming a fine resist pattern using the resin composition, and It aims at providing the polymer which can be used as resin.

The resin composition for forming a fine pattern of the present invention is a resin composition for forming a fine pattern, which contains a resin, a cross-linking agent that crosslinks the resin, and a solvent, and for refining a resist pattern. Is selected from at least one repeating unit selected from repeating units represented by the following formulas (1-1) to (1-3) and repeating units represented by the following formulas (2) to (5). It contains at least one repeating unit.

In Formula (1-1) to Formula (1-3), R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, X is a single bond, an oxygen atom (—O—), or a carbonyloxy group. (— (C═O) O—) or a methyleneoxy group (—CH ₂ O—), and R ² represents a methylresin group (—CH═), a methylmethylene group (—CH (CH ₃ ) —), or Represents a cyclohexyl group, a phenyl group, an adamantane group, a norbornene group, or a cyclic ether group, in which some hydrogen atoms may be substituted with a hydroxy group or a halogen atom, and R ³ independently represents a methyl group or a trivalent group. R ⁴ represents a fluoromethyl group, R ⁴ independently represents a hydrogen atom or a group that generates a hydrogen atom by the action of an acid, the group may be substituted with fluorine, and R ⁵ represents an aliphatic ring or phenyl group. N represents 0, 1 or 2, and m represents 0 or 1.

式（６）または式（７）において、Ｒ¹⁵は相互に独立に水素原子、または炭素数１〜１０の直鎖状もしくは分岐状のアルキル基を表す。 In the formula (2), R ⁶ represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxyl group having 1 to 8 carbon atoms,
In the formula (3), R ⁷ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group, and A represents a single bond, an oxygen atom, a carbonyl group, a carbonyl group An oxy group or an oxycarbonyl group, an alkylene group having 1 to 20 carbon atoms, a divalent monocyclic hydrocarbon ring group having 3 to 8 carbon atoms, or a divalent polycyclic hydrocarbon ring group having 7 to 10 carbon atoms R ⁸ represents a linear or branched alkyl group having 1 to 8 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom,
In Formula (4) and Formula (5), R ⁹ and R ¹² represent a hydrogen atom, a methyl group or a trifluoromethyl group,
In the formula (4), R ¹⁰ represents a methylene group, an ethylene group or a propylene group, R ¹¹ is a group represented by the following formula (6) or the following formula (7),
In the formula (5), R ¹³ represents a methylene group or an alkylene group having 2 to 6 carbon atoms, R ¹⁴ represents a hydrogen atom, a methyl group or an ethyl group, and r is 0 or 1.

In the formula (6) or the formula (7), R ¹⁵ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

式（８）において、ＢおよびＤは相互に独立に、単結合、メチレン基、炭素数２〜１０の直鎖状もしくは分岐状のアルキレン基、または、炭素数３〜２０の２価の脂環式炭化水素基を表し、Ｅは炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、炭素数３〜２０の１価の脂環式炭化水素基を表し、ｐは２〜４の整数、ｑは０または１を表し、
式（９）において、Ｚは炭素数３〜２０の脂環式炭化水素基を表し、酸素原子、窒素原子および硫黄原子を含んでいてもよく、ｐ’は１〜６の整数を表し、Ｒ¹⁶およびＲ¹⁷は、水素原子、または下記式（９−１）で表される基を表し、Ｒ¹⁶およびＲ¹⁷の少なくとも１つは下記式（９−１）で表される基であり、

式（９−１）において、Ｒ¹⁸およびＲ¹⁹は、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシアルキル基、またはＲ¹⁸とＲ¹⁹とが互いに連結した炭素数２〜１０の環を表し、Ｒ²⁰は、水素原子または炭素数１〜６のアルキル基を表す。 Moreover, the crosslinking agent which bridge | crosslinks the resin used for the resin composition for fine pattern formation contains at least 1 compound chosen from the compound represented by following formula (8) and the compound represented by following formula (9). It is characterized by that.

In Formula (8), B and D are each independently a single bond, a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a divalent alicyclic ring having 3 to 20 carbon atoms. Represents a hydrocarbon group, E represents a linear or branched alkyl group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and p is an integer of 2 to 4 , Q represents 0 or 1,
In the formula (9), Z represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms, may contain an oxygen atom, a nitrogen atom and a sulfur atom, p ′ represents an integer of 1 to 6, and R ¹⁶ and R ¹⁷ represent a hydrogen atom or a group represented by the following formula (9-1), and at least one of R ¹⁶ and R ¹⁷ is a group represented by the following formula (9-1);

In Formula (9-1), R ¹⁸ and R ¹⁹ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or the number of carbon atoms in which R ¹⁸ and R ¹⁹ are connected to each other. represents from 2 to 10 rings, R ²⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

  The fine pattern forming method of the present invention includes a pattern forming step of forming a resist pattern on a substrate, a coating step of covering the resist pattern with the resin composition for forming a fine pattern of the present invention, and a step after the coating step. The method includes a step of heat-treating the substrate and a step of developing with an alkaline aqueous solution.

  The polymer of this invention is used as resin of the resin composition for fine pattern formation of the said invention. This polymer includes at least one repeating unit selected from repeating units represented by the above formulas (1-1) to (1-3), and a repeating unit represented by the following formulas (2) to (5). Including at least one repeating unit selected from the units, and having a weight average molecular weight of 1,000 to 50,000.

The fine pattern forming resin composition of the present invention is a resin having a fluorinated hydrocarbon alcohol group, particularly at least one repeating unit selected from repeating units represented by the above formulas (1-1) to (1-3). By using a resin composed of a polymer containing units, the coating property to the resist pattern is excellent, and the dimensional controllability of the cured film is also excellent. Therefore, regardless of the surface state of the substrate, the pattern gap of the resist pattern can be effectively and accurately miniaturized, and the pattern exceeding the wavelength limit can be satisfactorily and economically reduced with few pattern defects. It can be formed in a state.
In particular, the resin composition for forming a fine pattern of the present invention has a large amount of shrinkage of the resin due to the combination with a crosslinking component, low temperature dependency during shrinkage, excellent formation of a fine space pattern after shrinkage, and pitch dependency. Therefore, the process window, which is a pattern formation margin against process variations, is wide.
Furthermore, by performing dry etching using the fine resist pattern thus formed as a mask, a trench pattern and a hole can be formed with high precision on a semiconductor substrate, and a semiconductor device having a fine trench pattern and a hole can be easily obtained. In addition, it can be manufactured with good yield.

Cross section of hole pattern Cross section of hole pattern

The inventors of the present invention have made extensive studies on a resin composition that can smoothly contract a resist pattern by heat treatment and can be easily removed by subsequent alkaline aqueous solution treatment. Thru | or the resin composition containing the alcohol soluble resin containing the at least 1 repeating unit (henceforth repeating unit (1)) chosen from the repeating unit represented by Formula (1-3), a crosslinking agent, and a solvent. It has been found that a fine pattern can be efficiently formed by using a product, and the present invention has been completed based on this finding.
The resin composition for forming a fine pattern of the present invention is a composition comprising a resin, a crosslinking agent and a solvent.

Repeating unit (1)
The resin that can be used in the present invention is a resin containing at least one repeating unit selected from repeating units represented by formulas (1-1) to (1-3). This resin is a repeating unit containing a fluorinated hydrocarbon alcohol group and at least one group selected from a group that generates a fluorinated hydrocarbon alcohol group by the action of an acid.

Of formula (1-1), formula (1-2), and formula (1-3), a preferred example is formula (1-1). Among the formulas (1-1), a repeating unit represented by the following formula (1-4) in which n is 0 and X is a carbonyloxy group (— (C═O) O—) is preferable. R ¹ to R in the formula (1-4) ^4, are respectively the same as R ¹ to R ⁴ in formula (1-1).

The repeating unit (1-4) can be obtained by polymerizing a (meth) acrylic acid derivative as a monomer. As a monomer for generating the repeating unit (1-4) (hereinafter, also referred to as “monomer (1)”), 1,1,1-trifluoro-2-hydroxy-2- (trifluoromethyl) Pent-4-yl (meth) acrylate, 1,1,1-trifluoro-2-hydroxy-2- (trifluoromethyl) hex-5-yl (meth) acrylate, 1,1,1-trifluoro-2 -Hydroxy-2- (trifluoromethyl) hept-6-yl (meth) acrylate, 1,1,1-trifluoro-2-hydroxy-2- (trifluoromethyl) hept-5-yl (meth) acrylate, (Meth) acrylic acid 2-((5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl) bicyclo [2.2.1] heptyl) ester, (Meta Acrylic acid 3 - ((8- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl) tetracyclo [6.2.1.1 ^3,6 .0 ^{2 , 7} ] dodecyl) ester and the like. Of these, 1,1,1-trifluoro-2-hydroxy-2- (trifluoromethyl) pent-4-yl methacrylate is preferable.
In addition, only one type of repeating unit (1) may be contained in the resin, and two or more types of repeating units (1) may be included.

Resins that can be used in the present invention include the repeating unit (1), the repeating unit represented by the above formula (2) (hereinafter also referred to as the repeating unit (2)), and the repeating unit represented by the above formula (3) ( Hereinafter, the repeating unit (3)), the repeating unit represented by the above formula (4) (hereinafter also referred to as the repeating unit (4)), and the repeating unit represented by the above formula (5) (hereinafter referred to as the repeating unit). A copolymer containing at least one repeating unit (hereinafter also referred to as another repeating unit) selected from the unit (5) is preferable.
A preferred resin is a copolymer of the repeating unit (1) and other repeating units. The blending ratio of the monomer in this copolymer is such that the monomer that generates another repeating unit is included within the following range, and the remaining monomer is a monomer that generates the repeating unit (1). Is preferred.

Repeating unit (2)
Examples of the linear or branched alkyl group having 1 to 8 carbon atoms or the linear or branched alkoxyl group having 1 to 8 carbon atoms represented by R ⁶ in the formula (2) include a t-butyl group and an acetoxy group. 1-ethoxyethoxy group and t-butoxyl group are preferable, and t-butoxyl group is most preferable.
The repeating unit (2) can be obtained by polymerizing a styrene acid derivative as a monomer. A preferred monomer for producing the repeating unit (2) is pt-butoxystyrene.
The ratio of the monomer which forms the repeating unit (2) is usually 10 to 60 mol%, preferably 20 to 50 mol%, based on all monomers constituting the copolymer. If it is less than 10 mol%, the shrinkage dimension may not increase, and if it exceeds 60 mol%, the solubility in the developer will deteriorate.

Repeating unit (3)
Examples of the alkyl group having 1 to 10 carbon atoms R ⁷ in the formula (3) include a methyl group. Preferred R ⁷ is a hydrogen atom or a methyl group.
Examples of the alkylene group having 1 to 20 carbon atoms represented by A include propylene group such as methylene group, ethylene group, 1,3-propylene group or 1,2-propylene group, tetramethylene group, pentamethylene group, hexamethylene. Group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptacamethylene group, Octadecamethylene group, nonacamethylene group, eicosamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1- Examples thereof include a methyl-1,4-butylene group and a 2-methyl-1,4-butylene group.
Examples of the divalent monocyclic hydrocarbon ring group having 3 to 8 carbon atoms include cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, Cyclohexylene group such as 1,4-cyclohexylene group, cyclooctylene group such as 1,5-cyclooctylene group, and the like.
Examples of the divalent polycyclic hydrocarbon ring group having 7 to 10 carbon atoms include norbornylene groups such as 1,4-norbornylene group or 2,5-norbornylene group, 1,5-adamantylene group, 2,6 An adamantylene group such as an adamantylene group;

Examples of the linear or branched alkyl group having 1 to 8 carbon atoms in which at least one hydrogen atom represented by R ⁸ in Formula (3) is substituted with a fluorine atom include a difluoromethyl group, a perfluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2 , 2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2, 2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octa Fluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3 , 3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, 2- (perfluoropentyl) ethyl group, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5 , 6,6-dodecafluoroheptyl group, perfluorohexylmethyl group, perfluoroheptyl group, 2- (perfluorohexyl) ethyl group, 1,1,2,2,3,3,4,4,5,5 , 6,6,7,7-tetradecafluorooctyl group, perfluoroheptylmethyl group, perfluorooctyl group, and 2- (perfluoroheptyl) ethyl group.
Especially, since the solubility to alkaline aqueous solution will become low when carbon number of a fluoroalkyl group becomes large too much, a perfluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group are preferable.

Preferable examples of the monomer that generates the repeating unit (3) represented by the formula (3) include 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate, 2-(((tri Fluoromethyl) sulfonyl) amino) ethyl-1-acrylate, as well as the following compounds:

  It is preferable that the ratio of the monomer which produces | generates a repeating unit (3) is 3-30 mol% with respect to all the monomers which comprise a copolymer, Preferably it is 5-12 mol%. If it is less than 3 mol%, it may be difficult to form a fine space pattern after shrinkage of the resin, and if it exceeds 30 mol%, the shrinkage amount of the resin decreases.

Repeating unit (4)
In the repeating unit (4) represented by the formula (4), R ⁹ is a methyl group, R ¹⁰ is an ethylene group, and R ¹¹ is a group represented by the formula (6) or the formula (7). preferable.
In formula (6) or formula (7), the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ¹⁵ includes a methyl group, an ethyl group, a 1,3-propyl group, or 1, Propyl group such as 2-propyl group, tetramethyl group, pentamethyl group, hexamethyl group, heptamethyl group, octamethyl group, nonamethyl group, decamethyl group, 1-methyl-1,3-propyl group, 2-methyl-1,3- A propyl group, 2-methyl-1,2-propyl group, 1-methyl-1,4-butyl group, 2-methyl-1,4-butyl group and the like can be mentioned.
The ratio of the monomer which forms the repeating unit (4) is 5 to 40 mol%, preferably 10 to 20 mol%, based on all monomers constituting the copolymer. If it is less than 5 mol%, the shrinkage dimension may not increase, and if it exceeds 40 mol%, the solubility in the developer will deteriorate.

Repeating unit (5)
In the repeating unit (5) represented by the formula (5), R ¹² is preferably a methyl group, R ¹³ is preferably a methylene group, and R ¹⁴ is preferably a hydrogen atom.
The ratio of the monomer which forms the repeating unit (5) is 5 to 40 mol%, preferably 10 to 20 mol%, based on all monomers constituting the copolymer. If it is less than 5 mol%, the shrinkage dimension may not increase, and if it exceeds 40 mol%, the solubility in the developer will deteriorate.

For example, the copolymer includes a mixture of monomers using radical polymerization initiators such as hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, and chain transfer agents as necessary. Can be produced by polymerization in a suitable solvent.
Examples of the 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 chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene; ethyl acetate Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate, methyl propionate, propylene glycol monomethyl ether acetate; alkyl lactones such as γ-butyrolactone; tetrahydrofuran, dimethoxyethanes, diethoxyethanes, etc. Ethers; alkyl ketones such as 2-butanone, 2-heptanone and methyl isobutyl ketone; cycloalkyl ketones such as cyclohexanone; 2-propanol, 1-butanol, 4-methyl-2-pentanol, propylene glycol monomethyl ether, etc. Alcohols and the like. These solvents can be used alone or in combination of two or more.

  Moreover, the reaction temperature in the said superposition | polymerization is 40-120 degreeC normally, Preferably it is 50-100 degreeC, and reaction time is 1-48 hours normally, Preferably it is 1-24 hours.

The copolymer preferably has a high purity, and not only has a low content of impurities such as halogen and metal, but the residual monomer and oligomer components are not more than predetermined values, for example, 0.1% by mass by HPLC analysis. The following is preferable. This not only can further improve the process stability, pattern shape, etc. of the resin composition for forming a fine pattern of the present invention containing a copolymer as a resin, but also changes over time such as foreign matter in liquid and sensitivity. A resin composition for forming a fine pattern can be provided.
The following method is mentioned as a purification method of the copolymer obtained by the above methods. As a method for removing impurities such as metals, a method in which a metal in a polymerization solution is adsorbed using a zeta potential filter, a metal is chelated and removed by washing the polymerization solution with an acidic aqueous solution such as oxalic acid or sulfonic acid. And the like. In addition, as a method of removing residual monomers and oligomer components below the specified value, liquid-liquid extraction method that removes residual monomers and oligomer components by combining water washing and an appropriate solvent, a specific molecular weight or less Refining method to remove residual monomers by coagulating resin in poor solvent by dripping polymerization solution into poor solvent And a purification method in a solid state such as washing with a poor solvent for the resin slurry separated by filtration. Moreover, you may combine these methods.

  The weight average molecular weight Mw of the copolymer thus obtained is usually 1,000 to 500,000, preferably 1,000 to 50,000, particularly preferably 1,000 to 20, in terms of gel permeation chromatography polystyrene. , 000. If the molecular weight is too large, there is a possibility that it cannot be removed with a developer after thermosetting, and if it is too small, a uniform coating film may not be formed after coating.

The crosslinking agent for crosslinking the resin used in the resin composition for forming a fine pattern of the present invention is a compound having two or more cyclic ethers represented by the above formula (8) (hereinafter referred to as “crosslinking agent I”) and It contains at least one compound selected from the compound represented by the above formula (9) (hereinafter referred to as “crosslinking agent II”).
Examples of the linear or branched alkylene group having 2 to 10 carbon atoms represented by B and D in the formula (8) of the crosslinking agent I include an ethylene group, a 1,3-propylene group or a 1,2-propylene group. And propylene group, tetramethylene group, pentamethylene group, hexamethylene group and the like.
Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cycloheptylene group, cyclooctylene group, and 1,4-norbornylene. Group, norbornylene group such as 2,5-norbornylene group, adamantylene group such as 1,5-adamantylene group, 2,6-adamantylene group and the like.
Examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by E in Formula (8) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an isopropyl group, An isobutyl group etc. are mentioned.
p is an integer of 2 to 4, preferably 2, and q is 0 or 1, preferably 1.
Preferred crosslinking component I includes 1,2-benzenedicarboxylic acid bis [(3-ethyl-3-oxetanyl) methyl] ester, 1,4-benzenedicarboxylic acid bis [(3-ethyl-3-oxetanyl) methyl] ester And bis [(3-ethyl-3-oxetanyl) methyl] ester of isophthalic acid.
The crosslinking agents I can be used alone or in combination of two or more.

In formula (9) of crosslinking agent II, Z represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and may contain an oxygen atom, a nitrogen atom and a sulfur atom, and p ′ is an integer of 1 to 6 Represents. Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms include alicyclic hydrocarbon groups derived from a cyclobutyl ring, a cyclopentyl ring, a cyclohexyl ring, a cyclooctyl ring, a norbornyl ring, and an adamantyl ring.
R ¹⁶ and R ¹⁷ represent a hydrogen atom or a group represented by the above formula (9-1), and at least one of R ¹⁶ and R ¹⁷ represents a group represented by the above formula (9-1). It is.
In Formula (9-1), R ¹⁸ and R ¹⁹ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or the number of carbon atoms in which R ¹⁸ and R ¹⁹ are connected to each other. represents from 2 to 10 rings, R ²⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The compound represented by the formula (9) (crosslinking agent II) is a compound having an imino group, a methylol group, a methoxymethyl group or the like as a functional group in the molecule, and (poly) methylol melamine, (poly) methylolation Examples thereof include nitrogen-containing compounds obtained by alkyl etherifying all or part of active methylol groups such as glycoluril, (poly) methylolated benzoguanamine, and (poly) methylolated urea. Here, examples of the alkyl group include a methyl group, an ethyl group, a butyl group, or a mixture thereof, and may contain an oligomer component that is partially self-condensed. Specific examples include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, and tetrabutoxymethylated glycoluril.
The commercially available compounds include Cymel 300, 301, 303, 350, 232, 235, 236, 238, 266, 267, 285, 1123, 1123-10, 1170, 370, 771, 272, 1172, 325, 327, 703, 712, 254, 253, 212, 1128, 701, 202, 207 (Japan) Made by Cytec Co., Ltd.), Nicarak E-6401, Nicarak MW-30M, 30, 22, 22, 24X, Nicarak MS-21, 11, 001, Nicarax MX-002, 730, 750, 708, 708, 706, 042, 035, 45, 410, 302, 202, Nikarak SM-651, 652, 653, 551, 45 Nicalack SB-401, 355, 303, 301, 255, 203, 201, Nicalack BX-4000, 37, 55H, Nicalack BL-60 (manufactured by Sanwa Chemical Co., Ltd.), etc. Can be mentioned. Preferably, any one of R ¹⁶ and R ¹⁷ in Formula 4 is a hydrogen atom, that is, Cymel 325, 327, 703, 712, 254, 253, which are crosslinking components containing an imino group. 212, 1128, 701, 202, and 207 are preferable.

    In addition to the crosslinking agent I and the crosslinking agent II, other crosslinking agents can be used for the crosslinking agent used in the present invention. The other crosslinking agent is preferably a compound having a polymerizable double bond at the molecular end, and examples thereof include pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and pentaerythritol diacrylate. . Of these, pentaerythritol tetraacrylate and pentaerythritol triacrylate are preferred because of their good thermosetting properties.

The crosslinking agent functions as a crosslinking component (curing component) in which the above-described resin and / or crosslinking component react with each other by the action of acid and heat.
The compounding quantity of the crosslinking agent in this invention is 1-100 mass parts with respect to 100 mass parts of resin, Preferably it is 5-70 mass parts. If the blending amount is less than 1 part by mass, curing may be insufficient and the pattern may not shrink, and if it exceeds 100 parts by mass, curing may proceed excessively and the pattern may be buried. Further, among all the crosslinking agents, the crosslinking agent I is 1 to 100% by mass, preferably 5 to 90% by mass, the crosslinking agent II is 1 to 80% by mass, preferably 5 to 60% by mass, and other crosslinking agents. An agent is 1-50 mass%, Preferably it is 5-40 mass%.
The total amount of the resin and the crosslinking agent is 0.1 to 30% by mass, preferably 1 to 20% by mass, based on the entire resin composition including the alcohol solvent described later. If the total amount of the resin and the cross-linking component is less than 0.1% by mass, the coating film may become too thin and the pattern-etched portion may be broken. If it exceeds 30% by mass, the viscosity becomes too high and the pattern is embedded in a fine pattern. There is a risk that it will not be possible.

The solvent that can be used in the present invention is preferably an alcohol solvent. In particular, the alcohol solvent is a solvent that sufficiently dissolves the resin and the cross-linking agent and does not cause intermixing with the photoresist film when applied onto the photoresist film. Can be used.
Such a solvent is preferably a monohydric alcohol having 1 to 8 carbon atoms. For example, 1-propanol, isopropanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1- Butanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3 -Methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 1-heptanol, 2- Heptanol, 2-methyl-2-heptanol, 2-methyl-3-heptanol, and the like, such as 1-butanol, 2-butanol, - methyl-2-pentanol are preferred. These alcohol solvents can be used alone or in combination of two or more.
The alcohol solvent can contain 10% by mass or less, preferably 1% by mass or less of water based on the total solvent. If it exceeds 10% by mass, the solubility of the resin decreases. More preferably, it is an anhydrous alcohol solvent containing no water.

The resin composition for forming a fine pattern of the present invention can be mixed with another solvent for the purpose of adjusting applicability when applied on a photoresist film. Other solvents have the effect of uniformly applying the resin composition for forming a fine pattern without eroding the photoresist film.
Other solvents include cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether Alkyl ethers of polyhydric alcohols such as diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate And alkyl ether acetates of polyhydric alcohols such as propylene glycol monomethyl ether acetate; aromatic hydrocarbons such as toluene and xylene; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone , Ketones such as diacetone alcohol; ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, hydroxyacetic acid Ethyl, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, acetic acid Chill, esters such as butyl acetate, and water. Among these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, esters, and water are preferable.

  The blending ratio of the other solvent is 30% by mass or less, preferably 20% by mass or less, based on the total solvent. If it exceeds 30% by mass, the photoresist film may be eroded, causing problems such as intermixing with the resin composition for forming a fine pattern, and the resist pattern may be buried. In addition, when water is mixed, it is 10 mass% or less.

A surfactant may be added to the resin composition for forming a fine pattern of the present invention for the purpose of improving coating properties, antifoaming properties, leveling properties and the like.
Examples of such surfactants include BM-1000, BM-1100 (above, manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (above, manufactured by Dainippon Ink & Chemicals, Inc.). ), FLORARD FC-135, FC-170C, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S- 141, S-145 (made by Asahi Glass Co., Ltd.), SH-28PA, -190, -193, SZ-6032, SF-8428 (above, made by Toray Dow Corning Silicone) Fluorosurfactants marketed by name can be used.
The blending amount of these surfactants is preferably 5% by mass or less with respect to 100 parts by mass of the resin.

A fine pattern is formed by the following method using the resin composition for forming a fine pattern.
(1) Formation of resist pattern An antireflection film (organic film or inorganic film) is formed on an 8-inch or 12-inch silicon wafer substrate by a conventionally known method such as spin coating. Next, a photoresist is applied by a conventionally known method such as spin coating, and prebaking (PB) is performed under conditions of, for example, about 80 ° C. to 140 ° C. and about 60 to 120 seconds. Then, exposure with ultraviolet rays such as g-line and i-line, KrF excimer laser beam, ArF excimer laser beam, X-ray, electron beam, etc., for example, post-exposure baking (PEB) under conditions of about 80 ° C to 140 ° C Then, development is performed to form a resist pattern.
(2) Formation of a fine pattern The resin composition for forming a fine pattern of the present invention is applied to a substrate on which the resist pattern is formed by a conventionally known method such as spin coating. The solvent may be volatilized only by spin coating to form a coating film. Moreover, if necessary, for example, prebaking (PB) is performed at about 80 ° C. to 110 ° C. for about 60 to 120 seconds to form a coating film of the resin composition for forming a fine pattern.
Next, the substrate on which the resist pattern is coated with the fine pattern forming resin composition is heat-treated. By the heat treatment, the acid derived from the photoresist diffuses from the interface with the photoresist into the resin composition layer for forming a fine pattern, and the resin composition for forming a fine pattern causes a crosslinking reaction. The cross-linking reaction state from the photoresist interface is determined by the material of the resin composition for fine pattern formation, the photoresist used, the baking temperature and the baking time. The heat treatment temperature and heat treatment time are usually about 90 ° C. to 160 ° C. and about 60 to 120 seconds.
Next, the coating film of the resin composition for forming a fine pattern is developed (for example, about 60 to 120 seconds) with an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) to form an uncrosslinked fine pattern. The coating film of the resin composition is dissolved and removed. Finally, a hole pattern, an elliptical pattern, a trench pattern, etc. can be made finer by washing with water.
(3) Removal of resist pattern by etching treatment By applying an etching treatment to the resin composition for forming a fine pattern formed as a sidewall of the resist pattern, the resist pattern is removed in advance to form a fine pattern on the sidewall. By leaving the resin composition, a fine circuit pattern is transferred.

上記式（ｍ−１）で表される１，１，１−トリフルオロ−２−ヒドロキシ−２−（トリフルオロメチル）ペント−４−イルメタクリレート（以下、「単量体（ｍ−１）」ともいう）３９．７８ｇ（７０モル％）およびｐ−ｔ−ブトキシスチレン（以下、「単量体（ｍ−２）」ともいう）１０．２２ｇ（３０モル％）、およびアゾビスイソブチロニトリル１．２７ｇを６７ｇのメチルエチルケトン（ＭＥＫ）に溶解して溶液を調製した。調製した溶液を３３ｇのＭＥＫが入った反応容器内へ還流条件下（８２℃）１時間かけて滴下した後、３時間重合反応を行なった。反応容器を流水で冷却した後、メタノール１５０ｇとヘキサン３７５ｇを加えて洗浄し、メタノール層を回収した。回収したメタノール層にＭＥＫを３０ｇ加えると共に、メタノール１５０ｇとヘキサン３７５ｇを更に加えて洗浄した。メタノール層を４−メチル−２−ペンタノール（ＭＩＢＣ）で溶剤置換し、得られたＭＩＢＣ溶液から重合体を得た（収率７０％）。この重合体のＭｗは１０，０００であり、Ｍｗ／Ｍｎは１．５２であった。重合体のＭｗおよびＭｎの測定は、東ソー（株）社製ＧＰＣカラム（Ｇ２０００ＨＸＬ２本、Ｇ３０００ＨＸＬ１本、Ｇ４０００ＨＸＬ１本）を用い、流量１．０ミリリットル／分、溶出溶剤テトラヒドロフラン、カラム温度４０℃の分析条件で、単分散ポリスチレンを標準とするゲルパーミエーションクロマトグラフィ（ＧＰＣ）により測定した。
実施例１で得られた重合体を樹脂（Ｂ−１）とする。 The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited to these examples.
Example 1

1,1,1-trifluoro-2-hydroxy-2- (trifluoromethyl) pent-4-yl methacrylate represented by the above formula (m-1) (hereinafter referred to as “monomer (m-1)”) 39.78 g (70 mol%) and pt-butoxystyrene (hereinafter also referred to as “monomer (m-2)”) 10.22 g (30 mol%), and azobisisobutyronitrile A solution was prepared by dissolving 1.27 g in 67 g of methyl ethyl ketone (MEK). The prepared solution was dropped into a reaction vessel containing 33 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer was obtained from the obtained MIBC solution (yield 70%). This polymer had Mw of 10,000 and Mw / Mn of 1.52. The measurement of Mw and Mn of the polymer was carried out using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation, analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. And measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard.
Let the polymer obtained in Example 1 be resin (B-1).

単量体（ｍ−１）を３５．１３ｇ（６０モル％）、単量体（ｍ−２）を１２．２８ｇ（３５モル％）および上記式（ｍ−３）で表される単量体を２．６０ｇ（５モル％）、およびアゾビスイソブチロニトリル１．３１ｇを６７ｇのメチルエチルケトン（ＭＥＫ）に溶解して溶液を調製した。調製した溶液を３３ｇのＭＥＫが入った反応容器内へ還流条件下（８２℃）１時間かけて滴下した後、３時間重合反応を行なった。反応容器を流水で冷却した後、メタノール１５０ｇとヘキサン３７５ｇを加えて洗浄し、メタノール層を回収した。回収したメタノール層にＭＥＫを３０ｇ加えると共に、メタノール１５０ｇとヘキサン３７５ｇを更に加えて洗浄した。メタノール層を４−メチル−２−ペンタノール（ＭＩＢＣ）で溶剤置換し、得られたＭＩＢＣ溶液から重合体を得た（収率６５％）。得られた重合体を実施例１と同一の方法で測定したＭｗは１１，０００であり、Ｍｗ／Ｍｎは１．５２であった。
実施例２で得られた重合体を樹脂（Ｂ−２）とする。 Example 2

Monomer (m-1) 35.13 g (60 mol%), monomer (m-2) 12.28 g (35 mol%) and the monomer represented by the above formula (m-3) Was dissolved in 2.60 g (5 mol%) of azobisisobutyronitrile and 1.31 g of azobisisobutyronitrile in 67 g of methyl ethyl ketone (MEK). The prepared solution was dropped into a reaction vessel containing 33 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer was obtained from the obtained MIBC solution (yield 65%). Mw of the obtained polymer measured by the same method as in Example 1 was 11,000, and Mw / Mn was 1.52.
Let the polymer obtained in Example 2 be resin (B-2).

単量体（ｍ−１）を４１．４２ｇ（７０モル％）および上記式（ｍ−４）で表される単量体を８．５８ｇ（３０モル％）、およびアゾビスイソブチロニトリル０．６６ｇを６７ｇのメチルエチルケトン（ＭＥＫ）に溶解して溶液を調製した。調製した溶液を３３ｇのＭＥＫが入った反応容器内へ還流条件下（８２℃）１時間かけて滴下した後、３時間重合反応を行なった。反応容器を流水で冷却した後、メタノール１５０ｇとヘキサン３７５ｇを加えて洗浄し、メタノール層を回収した。回収したメタノール層にＭＥＫを３０ｇ加えると共に、メタノール１５０ｇとヘキサン３７５ｇを更に加えて洗浄した。メタノール層を４−メチル−２−ペンタノール（ＭＩＢＣ）で溶剤置換し、得られたＭＩＢＣ溶液から重合体を得た（収率７１％）。実施例１と同一の方法で測定した重合体のＭｗは１９，０００であり、Ｍｗ／Ｍｎは１．５１であった。
実施例３で得られた重合体を樹脂（Ｂ−３）とする。 Example 3

41.42 g (70 mol%) of the monomer (m-1), 8.58 g (30 mol%) of the monomer represented by the formula (m-4), and azobisisobutyronitrile 0 A solution was prepared by dissolving .66 g in 67 g of methyl ethyl ketone (MEK). The prepared solution was dropped into a reaction vessel containing 33 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer was obtained from the obtained MIBC solution (yield 71%). The Mw of the polymer measured by the same method as in Example 1 was 19,000, and Mw / Mn was 1.51.
Let the polymer obtained in Example 3 be resin (B-3).

単量体（ｍ−１）を４５．６７ｇ（９０モル％）および上記式（ｍ−５）で表される単量体を４．３３ｇ（１０モル％）、およびアゾビスイソブチロニトリル１．１３ｇを６７ｇのメチルエチルケトン（ＭＥＫ）に溶解して溶液を調製した。調製した溶液を３３ｇのＭＥＫが入った反応容器内へ還流条件下（８２℃）１時間かけて滴下した後、３時間重合反応を行なった。反応容器を流水で冷却した後、メタノール１５０ｇとヘキサン３７５ｇを加えて洗浄し、メタノール層を回収した。回収したメタノール層にＭＥＫを３０ｇ加えると共に、メタノール１５０ｇとヘキサン３７５ｇを更に加えて洗浄した。メタノール層を４−メチル−２−ペンタノール（ＭＩＢＣ）で溶剤置換し、得られたＭＩＢＣ溶液から重合体を得た（収率６５％）。実施例１と同一の方法で測定した重合体のＭｗは１８，０００であり、Ｍｗ／Ｍｎは１．５０であった。
実施例４で得られた重合体を樹脂（Ｂ−４）とする。 Example 4

45.67 g (90 mol%) of the monomer (m-1), 4.33 g (10 mol%) of the monomer represented by the above formula (m-5), and azobisisobutyronitrile 1 A solution was prepared by dissolving .13 g in 67 g methyl ethyl ketone (MEK). The prepared solution was dropped into a reaction vessel containing 33 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer was obtained from the obtained MIBC solution (yield 65%). The Mw of the polymer measured by the same method as in Example 1 was 18,000, and Mw / Mn was 1.50.
Let the polymer obtained in Example 4 be resin (B-4).

単量体（ｍ−１）を３９．４２ｇ（６６．５モル％）および上記式（ｍ−６）で表される単量体を１０．５８ｇ（３３．５モル％）、およびアゾビスイソブチロニトリル１．２６ｇを６７ｇのメチルエチルケトン（ＭＥＫ）に溶解して溶液を調製した。調製した溶液を３３ｇのＭＥＫが入った反応容器内へ還流条件下（８２℃）１時間かけて滴下した後、３時間重合反応を行なった。反応容器を流水で冷却した後、メタノール１５０ｇとヘキサン３７５ｇを加えて洗浄し、メタノール層を回収した。回収したメタノール層にＭＥＫを３０ｇ加えると共に、メタノール１５０ｇとヘキサン３７５ｇを更に加えて洗浄した。メタノール層を４−メチル−２−ペンタノール（ＭＩＢＣ）で溶剤置換し、得られたＭＩＢＣ溶液から重合体を得た（収率７０％）。実施例１と同一の方法で測定した重合体のＭｗは１７，０００であり、Ｍｗ／Ｍｎは１．５０であった。
実施例５で得られた重合体を樹脂（Ｂ−５）とする。 Example 5

39.42 g (66.5 mol%) of the monomer (m-1), 10.58 g (33.5 mol%) of the monomer represented by the above formula (m-6), and azobisiso A solution was prepared by dissolving 1.26 g of butyronitrile in 67 g of methyl ethyl ketone (MEK). The prepared solution was dropped into a reaction vessel containing 33 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer was obtained from the obtained MIBC solution (yield 70%). The Mw of the polymer measured by the same method as in Example 1 was 17,000, and Mw / Mn was 1.50.
Let the polymer obtained in Example 5 be resin (B-5).

単量体（ｍ−１）を４５．８１ｇ（９０モル％）および上記式（ｍ−７）で表される単量体を４．１９ｇ（１０モル％）、およびアゾビスイソブチロニトリル１．１４ｇを６７ｇのメチルエチルケトン（ＭＥＫ）に溶解して溶液を調製した。調製した溶液を３３ｇのＭＥＫが入った反応容器内へ還流条件下（８２℃）１時間かけて滴下した後、３時間重合反応を行なった。反応容器を流水で冷却した後、メタノール１５０ｇとヘキサン３７５ｇを加えて洗浄し、メタノール層を回収した。回収したメタノール層にＭＥＫを３０ｇ加えると共に、メタノール１５０ｇとヘキサン３７５ｇを更に加えて洗浄した。メタノール層を４−メチル−２−ペンタノール（ＭＩＢＣ）で溶剤置換し、得られたＭＩＢＣ溶液から重合体を得た（収率７２％）。実施例１と同一の方法で測定した重合体のＭｗは１６，５００であり、Ｍｗ／Ｍｎは１．５１であった。
実施例６で得られた重合体を樹脂（Ｂ−６）とする。 Example 6

45.81 g (90 mol%) of the monomer (m-1), 4.19 g (10 mol%) of the monomer represented by the above formula (m-7), and azobisisobutyronitrile 1 A solution was prepared by dissolving .14 g in 67 g methyl ethyl ketone (MEK). The prepared solution was dropped into a reaction vessel containing 33 g of MEK over 1 hour under reflux conditions (82 ° C.), followed by carrying out a polymerization reaction for 3 hours. After cooling the reaction vessel with running water, 150 g of methanol and 375 g of hexane were added and washed, and the methanol layer was recovered. 30 g of MEK was added to the recovered methanol layer, and 150 g of methanol and 375 g of hexane were further added for washing. The methanol layer was solvent-substituted with 4-methyl-2-pentanol (MIBC), and a polymer was obtained from the obtained MIBC solution (yield 72%). The Mw of the polymer measured by the same method as in Example 1 was 16,500, and Mw / Mn was 1.51.
Let the polymer obtained in Example 6 be resin (B-6).

Examples 7 to 18 and Comparative Examples 1 and 2
In the ratio shown in Table 1, a resin, a cross-linking agent and an alcohol solvent were added to the container and stirred for 3 hours, followed by filtration using a filter having a pore size of 0.03 μm to obtain a resin composition for forming a fine pattern. It was.
The crosslinking agent and alcohol solvent used in each example and comparative example are shown below.
Crosslinking agent C-1: 1,3-benzenedicarboxylic acid bis [(3-ethyl-3-oxetanyl) methyl] ester C-2: Nicalac E-6401 [melamine resin] (trade name, manufactured by Nippon Carbide)
C-3: Pentaerythritol tetraacrylate alcohol solvent S-1: 1-butanol S-2: 4-methyl-2-pentanol

In order to evaluate the obtained resin composition for forming a fine pattern, an evaluation substrate with a resist pattern was prepared by the following method.
After forming a coating film with a film thickness of 77 nm (PB205 ° C., 60 seconds) on a 8-inch silicon wafer by spin coating a lower antireflection film ARC29A (Brewer Science Co., Ltd.) with CLEAN TRACK ACT8 (Tokyo Electron Ltd.), Patterning of JSR ArF AR2676J (manufactured by JSR Corporation, alicyclic radiation-sensitive resin composition) is performed. The AR2676J uses the CLEAN TRACK ACT8 to form a coating film having a thickness of 150 nm by spin coating, PB (115 ° C., 60 seconds), and cooling (23 ° C., 30 seconds). ArF projection exposure apparatus S306C (Nikon Corporation) ), NA: 0.78, Sigma: 0.85, Quadrupole optical exposure (exposure 30 mJ / cm ² ), PEB (115 ° C., 60 seconds) on the CLEAN TRACK ACT8 hot plate, After cooling (23 ° C., 30 seconds), a paddle development using a 2.38 mass% TMAH aqueous solution as a developer at the LD nozzle of the developing cup (60 seconds), rinsing with ultrapure water, and then spinning by spinning at 4000 rpm for 15 seconds. It dried and obtained the board | substrate for evaluation. The substrate obtained in this step is referred to as an evaluation substrate A. A plurality of evaluation substrates A prepared under the same conditions were prepared.
The obtained evaluation substrate corresponds to a 90 nm diameter hole pattern and a 90 nm space mask pattern (bias +30 nm / 120 nm diameter pattern / 60 nm space on the mask) with a scanning electron microscope (S-9380 manufactured by Hitachi Keiki Co., Ltd.). The hole diameter of the resist pattern was measured.

Using the evaluation substrate with a resist pattern, the resin composition for forming a fine pattern in each Example shown in Table 1 was evaluated by the following method. Each evaluation result is shown in Table 2.
(1) Evaluation of shrinkage dimension and baking temperature dependency On the above-mentioned evaluation substrate A, a resin composition for forming a fine pattern described in Table 1 was applied by CLEAN TRACK ACT8 to a film thickness of 150 nm by spin coating. In order to react the pattern and the resin composition for forming a fine pattern, baking was performed under the shrinkage evaluation baking conditions described in Table 1. Then, after cooling with a CLEAN TRACK ACT8 at 23 ° C. for 30 seconds with a cooling plate for 30 seconds, using a development cup with a 2.38 wt% TMAH aqueous solution as a developer, paddle development (60 seconds), rinsing with ultra pure water, Subsequently, it spin-dried by shaking off at 4000 rpm for 15 seconds. The substrate obtained in this step is referred to as an evaluation substrate B. Shrinkage measurement of pattern dimensions was performed with a scanning electron microscope (S-9380, manufactured by Hitachi Sokki Co., Ltd.) with a hole pattern of about 60 to 90 nm diameter, a mask pattern of 90 to 120 nm space (bias +30 nm / 120 nm diameter pattern on the mask / The pattern corresponding to (60 nm space) was observed, and the hole diameter of the pattern was measured.
Shrinkage dimension (nm) = φ1-φ2
φ1: Resist pattern hole diameter of evaluation substrate A (nm)
φ2: resist pattern hole diameter of evaluation substrate B (nm)
As a judgment of shrinkage, “◯” is given when shrinkage is confirmed and the shrinkage dimension is 10 nm or more, and “X” is given when shrinkage is not confirmed or the pattern is collapsed or when the shrinkage dimension is less than 10 nm. .

(2) Confirmation and evaluation of insoluble matter The substrate B for evaluation was scanned with a scanning electron microscope (S-4800, manufactured by Hitachi Sokki Co., Ltd.) with a 60 to 90 m diameter hole pattern and a 90 to 120 nm space mask pattern (bias +30 nm / on mask) Is a cross section of a pattern corresponding to (120 nm diameter pattern / 60 nm space). When there is no insoluble matter at the bottom of the opening, “◯” is indicated, and when an insoluble matter is observed, “X” is indicated.
(3) Shape Evaluation after Pattern Shrinkage In the evaluation substrate A, a 60-90 nm diameter hole pattern, a 90-120 nm space mask pattern (bias + 30 nm / mask) with a scanning electron microscope (S-4800, manufactured by Hitachi Keiki Co., Ltd.) The top corresponds to 120 nm pattern / 60 nm space) and the cross section of the pattern existing at the same position is observed. The cross-sectional shape is shown in FIGS.
The angle of the side wall 2a of the hole pattern 2 with respect to the substrate 1 is a difference of 3 degrees or less between the angle θ before pattern shrinkage (FIG. 1 (a)) and the angle θ ′ after pattern shrinkage (FIG. 1 (b)) ( 1), and the resist film thickness t in the evaluation substrate A (FIG. 2 (a)) is 100, the resist film thickness t−t ′ from the substrate 1 exceeds 80 only on the evaluation substrate B. The pattern in which the deteriorated portion t ′ was recognized was regarded as good (FIG. 2B), and the others were regarded as defective (see FIG. 2).

  The resin composition for forming a fine pattern according to the present invention can effectively and accurately miniaturize the pattern gap between resist patterns, and can form a pattern that exceeds the wavelength limit in a favorable and economical manner. It can be used very suitably in the field of microfabrication represented by the manufacture of integrated circuit elements, which are expected to progress.

1 Substrate 2 Hole pattern

Claims (4)

A resin composition for forming a fine pattern, which contains a resin, a crosslinking agent that crosslinks the resin, and a solvent,
The resin is composed of at least one repeating unit selected from repeating units represented by the following formulas (1-1) to (1-3) and repeating units represented by the following formulas (2) to (5). A resin composition for forming a fine pattern, comprising at least one repeating unit selected.

(In Formula (1-1) to Formula (1-3), R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, and X represents a single bond, an oxygen atom, a carbonyloxy group, or methyleneoxy. R ² represents a methyl resin group, a methylmethylene group, or a hydroxy group or a halogen atom, and a part of hydrogen atoms may be substituted, a cyclohexyl group, a phenyl group, an adamantane group, a norbornene group, or a cyclic ether group R ³ represents a methyl group or a trifluoromethyl group independently of each other, R ⁴ independently represents a hydrogen atom or a group capable of generating a hydrogen atom by the action of an acid, and the group is fluorine. Optionally substituted, R ⁵ represents an aliphatic ring or a phenyl ring, n represents 0, 1 or 2, m represents 0 or 1,
In the formula (2), R ⁶ represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxyl group having 1 to 8 carbon atoms,
In the formula (3), R ⁷ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group, and A represents a single bond, an oxygen atom, a carbonyl group, a carbonyl group An oxy group or an oxycarbonyl group, an alkylene group having 1 to 20 carbon atoms, a divalent monocyclic hydrocarbon ring group having 3 to 8 carbon atoms, or a divalent polycyclic hydrocarbon ring group having 7 to 10 carbon atoms R ⁸ represents a linear or branched alkyl group having 1 to 8 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom,
In Formula (4) and Formula (5), R ⁹ and R ¹² represent a hydrogen atom, a methyl group or a trifluoromethyl group,
In the formula (4), R ¹⁰ represents a methylene group, an ethylene group or a propylene group, R ¹¹ is a group represented by the following formula (6) or the following formula (7),
In the formula (5), R ¹³ represents a methylene group or an alkylene group having 2 to 6 carbon atoms, R ¹⁴ represents a hydrogen atom, a methyl group or an ethyl group, and r is 0 or 1.

In the formula (6) or the formula (7), R ¹⁵ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms. ) The resin for forming a fine pattern according to claim 1, wherein the crosslinking agent contains at least one compound selected from a compound represented by the following formula (8) and a compound represented by the following formula (9). Composition.

(In Formula (8), B and D are each independently a single bond, a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a divalent fat having 3 to 20 carbon atoms. Represents a cyclic hydrocarbon group, E represents a linear or branched alkyl group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and p represents 2 to 4 An integer, q represents 0 or 1,
In the formula (9), Z represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms, may contain an oxygen atom, a nitrogen atom and a sulfur atom, p ′ represents an integer of 1 to 6, and R ¹⁶ and R ¹⁷ represent a hydrogen atom or a group represented by the following formula (9-1), and at least one of R ¹⁶ and R ¹⁷ is a group represented by the following formula (9-1);

In Formula (9-1), R ¹⁸ and R ¹⁹ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or the number of carbon atoms in which R ¹⁸ and R ¹⁹ are connected to each other. represents from 2 to 10 rings, R ²⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. )   A pattern forming step for forming a resist pattern on the substrate; a coating step for coating the resist pattern with the resin composition for forming a fine pattern according to claim 1; and a heat treatment for the substrate after the coating step. And a fine pattern forming method including a step of developing with an aqueous alkali solution. At least one repeating unit selected from the repeating units represented by the following formulas (1-1) to (1-3) and at least selected from the repeating units represented by the following formulas (2) to (5). A polymer comprising one repeating unit and having a weight average molecular weight of 1,000 to 50,000.

(In Formula (1-1) to Formula (1-3), R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, and X represents a single bond, an oxygen atom, a carbonyloxy group, or methyleneoxy. R ² represents a methyl resin group, a methylmethylene group, or a hydroxy group or a halogen atom, and a part of hydrogen atoms may be substituted, a cyclohexyl group, a phenyl group, an adamantane group, a norbornene group, or a cyclic ether group R ³ represents a methyl group or a trifluoromethyl group independently of each other, R ⁴ independently represents a hydrogen atom or a group capable of generating a hydrogen atom by the action of an acid, and the group is fluorine. Optionally substituted, R ⁵ represents an aliphatic ring or a phenyl ring, n represents 0, 1 or 2, m represents 0 or 1,
In the formula (2), R ⁶ represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxyl group having 1 to 8 carbon atoms,
In the formula (3), R ⁷ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group, and A represents a single bond, an oxygen atom, a carbonyl group, a carbonyl group An oxy group or an oxycarbonyl group, an alkylene group having 1 to 20 carbon atoms, a divalent monocyclic hydrocarbon ring group having 3 to 8 carbon atoms, or a divalent polycyclic hydrocarbon ring group having 7 to 10 carbon atoms R ⁸ represents a linear or branched alkyl group having 1 to 8 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom,
In Formula (4) and Formula (5), R ⁹ and R ¹² represent a hydrogen atom, a methyl group or a trifluoromethyl group,
In the formula (4), R ¹⁰ represents a methylene group, an ethylene group or a propylene group, R ¹¹ is a group represented by the following formula (6) or the following formula (7),
In the formula (5), R ¹³ represents a methylene group or an alkylene group having 2 to 6 carbon atoms, R ¹⁴ represents a hydrogen atom, a methyl group or an ethyl group, and r is 0 or 1.

In the formula (6) or the formula (7), R ¹⁵ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms. )

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