JP5375412B2 - Resin composition for forming fine pattern and method for forming fine pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for fine pattern formation, which smoothly shrinks a resist pattern by a heat treatment, and is easily removed by subsequent treatment with an aqueous alkali solution. <P>SOLUTION: The resin composition for fine pattern formation contains a resin, a crosslinking agent for crosslinking the resin, and a solvent and is used for microfabrication of a resist pattern. The resin contains a repeating unit (I) expressed by formula (1) and a repeating unit (II) expressed by formula (2). In the formula (1): R<SP>1</SP>represents a hydrogen atom or a methyl group; R<SP>2</SP>represents a single bond, a methylene group, a 2-5C chain or branched alkylene group, an -NH- group, an -O- group, a -COO- group, or a -CINH- group; R<SP>3</SP>each independently represents a hydrogen atom, a 1-6C saturated chain hydrocarbon group, a 3-8C monocyclic hydrocarbon group, or a 7-10C polycyclic hydrocarbon group; m represents 1 to 2; and n represents 0 to 2. In the second formula (2): R<SP>1</SP>represents a hydrogen atom or a methyl group; X represents a methylene group, a methylidene group, a 2-10C straight-chain or branched alkylene group, a 3-12C bivalent alicyclic hydrocarbon group, or a -NH- group; R<SP>4</SP>each independently represents 1-10C straight-chain or branched alkyl group, a 1-10C alkoxyl group, or a -O-Si=R'<SB>3</SB>group; R' each independently represents a 1-10C straight-chain or branched alkyl group or a 1-10C alkoxyl group. <P>COPYRIGHT: (C)2011,JPO&amp;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 and a method for forming a fine pattern, which are used when a pattern is shrunk by heat treatment after patterning. More specifically, by using a resin containing silicon atoms, high etching resistance to oxygen-based plasma is imparted, and by using a solvent, wettability to a photoresist pattern is improved, and a pattern having a diameter of 60 nm or less is formed. It can be easily coated without entraining bubbles, and when applying the resin composition for forming a fine pattern, it uses a lower layer film or photoresist when applying without applying a new water-based application cup or waste liquid treatment equipment. The present invention relates to a resin composition for forming a fine pattern and a method for forming a fine pattern, in which a cup or a waste liquid treatment facility can be used as it is.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, a lithography technique capable of microfabrication at a level of 100 nm or less is required. However, in the conventional lithography process, near-ultraviolet rays such as i-rays are generally used as radiation, and it is said that fine processing at a subquarter micron level is extremely difficult with this near-ultraviolet rays. Therefore, in order to enable microfabrication at a level of 100 nm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, an X-ray, an electron beam, and the like. Among these, a KrF excimer laser (wavelength 248 nm) is particularly preferable. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.

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

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

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

  However, it is said that the extension of the above-described exposure technique is limited to 45 nmhp, and technology development for the 32 nmhp generation that requires finer processing is being carried out. In addition, since an apparatus (immersion exposure apparatus) used for immersion exposure is extremely expensive, there is a fact that it is not practical in an actual semiconductor manufacturing process.

  On the other hand, there is a pattern forming method in which thin films formed on the left and right wall surfaces of a dummy pattern are used as a gate electrode after the dummy pattern is removed in order to reduce LWR (Linewidth Roughness) in accordance with the demand for more complex and higher density devices. It has been proposed (see Non-Patent Document 1, for example). In the pattern forming method proposed in Non-Patent Document 1, variation in threshold voltage of transistors is evaluated to reduce LWR. However, there is a situation that it is difficult to use for forming a finer pattern.

  As research to enable the formation of fine patterns that exceed the wavelength limit of the light source wavelength of the exposure apparatus, patterning an electron beam resist such as polymethylmethacrylate, applying a positive resist on the resist pattern, and then heating A method of forming a reaction layer at the boundary between the resist pattern and the positive resist layer by processing and removing a non-reacted portion of the positive resist to refine the resist pattern (Patent Document 3), a lower layer resist pattern and an upper layer A method of forming a reaction layer using an acid generator or thermal crosslinking with an acid between a resist (Patent Document 4) and an upper-layer resist coating solution that does not contain a photosensitive component and is a water-soluble resin or a water-soluble crosslinking agent Or a method of manufacturing a semiconductor device using a fine pattern forming material obtained by dissolving a mixture of these in a water-soluble solvent (Patent Document 5), on a substrate A photosensitive layer made of a chemically amplified resist is provided, and after image formation exposure, development processing is performed to form a resist pattern. On this resist pattern, a water-soluble resin such as polyvinyl acetal or tetra (hydroxymethyl) glycoluril is formed. A film-former containing a water-soluble cross-linking agent, a water-soluble nitrogen-containing organic compound such as an amine, and optionally a fluorine- and silicon-containing surfactant, followed by heat treatment to form a resist pattern and a finer resist pattern A method of forming a water-insoluble reaction layer at the interface with the coating film and then removing a non-reacted portion of the resist pattern refinement coating film with pure water has been proposed (Patent Document 6).

  These methods are preferable in that the pattern of the resist pattern (lower layer resist) can be easily refined beyond the wavelength limit of the photosensitive resist (upper layer resist). Cross-linking of the fine pattern forming material up to the unnecessary part of the bottom part, a skirted shape, the perpendicularity of the cross-sectional shape of the fine pattern forming material is poor, or the upper resist pattern size is cross-linked However, there is a problem that the pattern shape is influenced by mixing baking, which is a heating for heating, and it cannot be said that it is sufficiently satisfactory. In addition, these processes are highly dependent on heat of several tens of nm / ° C., and it is difficult to maintain a uniform temperature in the wafer surface when the substrate is enlarged and the pattern is miniaturized. There is a problem that the dimensional controllability of the lowering. Furthermore, the fine pattern forming material using the above water-soluble resin has a problem of low resistance to dry etching due to the limitation of solubility in water. In manufacturing a semiconductor device, a pattern is transferred onto a substrate by dry etching using a resist pattern as a mask. However, when the resistance to dry etching is low, there is a problem that the resist pattern cannot be accurately transferred onto the substrate.

  In addition, after forming a photoresist pattern on the substrate, heat or radiation is applied to it to fluidize the photoresist pattern, and the so-called thermal flow process is developed to make the pattern dimension smaller than the resolution limit. A method of forming a photoresist pattern on a substrate and then providing a water-soluble resin film thereon to control the flow of the photoresist has been proposed (Patent Document 7). The polyvinyl alcohol used in this method has been proposed. Such a water-soluble resin has the disadvantages that the solubility and stability over time required at the time of removal with water are insufficient and a residue is generated.

  Alternatively, 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 contracted 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 pattern refinement coating method (Patent Document 8) 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.

  As a polymer containing a silicon atom-containing acrylic monomer in the molecule, a polymer compound containing a specific silicon atom-containing substituent is known (for example, see Patent Document 9). However, this polymer is not disclosed as a copolymer with a monomer having a hydroxyl group derived from phenols in the side chain.

Japanese Patent Laid-Open No. 5-232704 JP-A-10-303114 Japanese Patent No. 2723260 JP-A-6-250379 Japanese Patent Laid-Open No. 10-73927 Japanese Patent Laid-Open No. 2001-19860 JP 7-45510 A JP 2003-195527 A JP 2001-278918 A

International Electron Devices Meeting Technical Digest, pp. 863-866, Dec. 2005

  The present invention has been made to cope with such a problem. When a fine pattern is formed by heat-treating a resist pattern, the fine pattern is simply and easily applied on the resist pattern by heat treatment. An object of the present invention is to provide a highly practical pattern forming method that can be efficiently formed and applied to a semiconductor manufacturing process, and a resin composition used therefor.

式（１）において、Ｒ¹は水素原子またはメチル基を表し、Ｒ²は単結合、メチレン基、炭素数２〜５の鎖状もしくは分岐状のアルキレン基、−ＮＨ−基、−Ｏ−基、−ＣＯＯ−基、または−ＣＯＮＨ−基を表し、Ｒ³はそれぞれ独立に水素原子、炭素数１〜６の飽和鎖状炭化水素基、炭素数３〜８の単環式炭化水素基、または炭素数７〜１０の多環式炭化水素基を表し、ｍ＝１〜２、ｎ＝０〜２を表す。
また、上記繰り返し単位（ＩＩ）が下記式（２）で表される繰り返し単位であることを特徴とする。

式（２）において、Ｒ¹は水素原子またはメチル基を表し、Ｘはメチレン基、炭素数２〜１０の直鎖状もしくは分岐状のアルキレン基、炭素数３〜１２の２価の脂環式炭化水素基、または−ＮＨ−基を表し、Ｒ⁴はそれぞれ独立に炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、炭素数１〜１０のアルコキシル基、または−Ｏ−Ｓｉ−Ｒ’₃基を表し、Ｒ’はそれぞれ独立に炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、または炭素数１〜１０のアルコキシル基を表す。 The resin composition for forming a fine pattern according to the present invention comprises a resin, a crosslinking agent for crosslinking the resin, and a solvent, and a resin composition for forming a fine pattern for making a resist pattern formed on a substrate fine. The resin includes a repeating unit (I) having a hydroxyl group derived from phenols in a side chain and a repeating unit (II) having a group containing a silicon atom in the side chain. .
The repeating unit (I) is a repeating unit represented by the following formula (1).

In the formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond, a methylene group, a chain or branched alkylene group having 2 to 5 carbon atoms, an —NH— group, an —O— group. , -COO- group, or -CONH- group, each R ³ independently represents a hydrogen atom, a saturated chain hydrocarbon group having 1 to 6 carbon atoms, a monocyclic hydrocarbon group having 3 to 8 carbon atoms, or A polycyclic hydrocarbon group having 7 to 10 carbon atoms is represented, and m = 1 to 2 and n = 0 to 2.
The repeating unit (II) is a repeating unit represented by the following formula (2).

In Formula (2), R ¹ represents a hydrogen atom or a methyl group, X is a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, and a divalent alicyclic group having 3 to 12 carbon atoms. Represents a hydrocarbon group or —NH— group, and each R ⁴ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or —O—Si—R. 'Represents ₃ groups, and R' each independently represents a linear or branched alkyl group having 1 to 10 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms.

式（３）において、Ｒ^1'は水素原子、メチル基またはトリフルオロメチル基を表し、Ｒ⁵は単結合、メチレン基、炭素数２〜６の直鎖状もしくは分岐状のアルキレン基、炭素数４〜１２の２価の脂環式炭化水素基、またはアルキレングリコールもしくはアルキレンエステルに由来する２価の基を表し、式（４）において、Ｒ⁶は水素原子、炭素数１〜８の直鎖状、分岐状もしくは環状のアルキル基、炭素数１〜８の直鎖状もしくは分岐状のアルコキシル基、ベンジロキシル基、ｔｅｒｔ−ブトキシカルボニル基、またはｔｅｒｔ−ブチルジメチルシロキシル基を表す。
また、上記繰り返し単位（ＩＩ）は、樹脂成分全体に含まれる全繰り返し単位を１００モル％としたときに、２０〜８０モル％含まれることを特徴とする。 The resin constituting the resin composition for forming a fine pattern of the present invention is represented by the repeating unit represented by the following formula (3) and the following formula (4) together with the repeating unit (I) and the repeating unit (II). It contains at least one repeating unit (III) selected from repeating units.

In the formula (3), R ^{1 ′} represents a hydrogen atom, a methyl group or a trifluoromethyl group, R ⁵ represents a single bond, a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, a carbon number Represents a divalent alicyclic hydrocarbon group having 4 to 12 or a divalent group derived from alkylene glycol or alkylene ester, and in formula (4), R ⁶ is a hydrogen atom, a straight chain having 1 to 8 carbon atoms. Represents a linear, branched or cyclic alkyl group, a linear or branched alkoxyl group having 1 to 8 carbon atoms, a benzyloxyl group, a tert-butoxycarbonyl group, or a tert-butyldimethylsiloxyl group.
The repeating unit (II) is characterized by being contained in an amount of 20 to 80 mol% when the total repeating units contained in the entire resin component is 100 mol%.

  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. It includes a step of heat-treating the substrate, a step of developing with an alkaline aqueous solution, and a step of etching.

  The resin composition for forming a fine pattern of the present invention comprises a repeating unit (I) having a hydroxyl group derived from phenols in a side chain and a repeating unit (II) having a group containing a silicon atom in the molecule in the side chain. Since the resin component to be used is used, a finer resist pattern can be easily and efficiently formed. For this reason, the pattern forming method of the present invention is highly practical and can be applied to a semiconductor manufacturing process.

Cross section of hole pattern Cross section of hole pattern

As a result of earnest research on the resin composition that can smoothly contract the resist pattern by heat treatment and can be easily removed by subsequent alkaline aqueous solution treatment, the present inventors have found that hydroxyl groups derived from phenols have been removed. A resin composition containing a crosslinking agent and a solvent, using a resin component comprising a repeating unit (I) in the side chain and a repeating unit (II) having a group containing a silicon atom in the molecule in the side chain. By using it, it has been found that a fine pattern can be efficiently formed and only a resist pattern is removed by etching to obtain a sidewall pattern, 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.

式（１）において、Ｒ¹は水素原子またはメチル基を表し、Ｒ²は単結合、メチレン基、炭素数２〜５の鎖状もしくは分岐状のアルキレン基、−ＮＨ−基、−Ｏ−基、−ＣＯＯ−基、または−ＣＯＮＨ−基を表し、Ｒ³はそれぞれ独立に水素原子、炭素数１〜６の飽和鎖状炭化水素基、炭素数３〜８の単環式炭化水素基、または炭素数７〜１０の多環式炭化水素基を表し、ｍは１〜２、ｎは０〜２の整数である。
炭素数２〜５の鎖状もしくは分岐状のアルキレン基としては、エチレン基、プロピレン基、ブチレン基等が挙げられる。
炭素数１〜６の飽和鎖状炭化水素基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基が挙げられ、炭素数３〜８の単環式炭化水素基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基、シクロヘプチル基、シクロオクチル基が挙げられ、炭素数７〜１０の多環式炭化水素基としては、ビシクロ［２．２．１］ヘプチル基、トリシクロ［５．２．１．０^2,6］デシル基、テトラシクロ［６．２．１^3,6．０^2,7］ドデカニル基、アダマンチル基が挙げられる。 The resin that can be used in the present invention contains a repeating unit having a hydroxyl group derived from phenols (hereinafter referred to as repeating unit (I)). Phenols are compounds in which a hydroxyl group is directly bonded to an aromatic ring. This repeating unit is preferably a repeating unit represented by the following formula (1).

In the formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond, a methylene group, a chain or branched alkylene group having 2 to 5 carbon atoms, an —NH— group, an —O— group. , -COO- group, or -CONH- group, each R ³ independently represents a hydrogen atom, a saturated chain hydrocarbon group having 1 to 6 carbon atoms, a monocyclic hydrocarbon group having 3 to 8 carbon atoms, or A C7-10 polycyclic hydrocarbon group is represented, m is 1-2, n is an integer of 0-2.
Examples of the chain or branched alkylene group having 2 to 5 carbon atoms include an ethylene group, a propylene group, and a butylene group.
Examples of the saturated chain hydrocarbon group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. As the monocyclic hydrocarbon group having 3 to 8 carbon atoms, , A cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic hydrocarbon group having 7 to 10 carbon atoms include a bicyclo [2.2.1] heptyl group. , Tricyclo [5.2.1.0 ^2,6 ] decyl group, tetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecanyl group and adamantyl group.

  Other monomers having a phenolic hydroxyl group for generating the repeating unit (I) include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, α-methyl-p-hydroxystyrene, α-methyl-m-. Hydroxystyrene, α-methyl-o-hydroxystyrene, 2-allylphenol, 4-allylphenol, 2-allyl-6-methylphenol, 2-allyl-6-methoxyphenol, 4-allyl-2-methoxyphenol, 4 -Allyl-2,6-dimethoxyphenol, 4-allyloxy-2-hydroxybenzophenone and the like can be exemplified, and among these, p-hydroxystyrene or α-methyl-p-hydroxystyrene is preferable.

The repeating unit (I) is obtained by polymerizing a monomer having a hydroxyl group derived from phenols and having a polymerizable unsaturated bond.
The repeating unit (I) is usually 20 to 80 mol%, preferably 30 to 80 mol%, based on 100 mol% of all repeating units contained in the entire resin component. If it is less than 20 mol%, there are too few reaction sites with the crosslinking agent described later, and pattern shrinkage cannot be caused. If it exceeds 80 mol%, swelling may occur during development and the pattern may be buried.

  Further, after the copolymerization, a monomer having a functional group that can be converted to a phenolic hydroxyl group can be copolymerized, for example, p-acetoxystyrene, α-methyl-p-acetoxystyrene, p-benzyloxystyrene, p -Tert-butoxystyrene, p-tert-butoxycarbonyloxystyrene, p-tert-butyldimethylsiloxystyrene and the like. When these functional group-containing compounds are used, the obtained resin can be easily converted into a phenolic hydroxyl group by appropriate treatment, for example, hydrolysis using hydrochloric acid or the like. it can. The repeating units derived from the monomers before and after conversion to these phenolic hydroxyl groups are usually 20 to 80 mol% when the total repeating units constituting the resin are 100 mol%.

The resin that can be used in the present invention contains both the above repeating unit (I) and the repeating unit (II) having a group containing a silicon atom in the side chain. As the repeating unit (II), a repeating unit represented by the above formula (2) is preferable.
In Formula (2), R ¹ represents a hydrogen atom or a methyl group, X is a methylene group (—CH ₂ —), a linear or branched alkylene group having 2 to 10 carbon atoms, or a 3 to 12 carbon atoms. Represents a divalent alicyclic hydrocarbon group or —NH— group, and each R ⁴ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or —O—Si—R ′ ₃ group is represented. R ′ each independently represents a linear or branched alkyl group having 1 to 10 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms.
Examples of the linear or branched alkylene group having 2 to 10 carbon atoms include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, and an octylene group.
Examples of the divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms include cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cycloheptylene group, cyclooctylene group, adamantylene group, norbornylene group, etc. Is mentioned.
Examples of the linear or branched alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
Examples of the alkoxyl group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

Examples of the repeating unit represented by the above formula (2) include the following formulas (2-1) to (2-18). Among these, the formulas (2-4), (2-9), Formula (2-10), formula (2-13), and formula (2-16) are preferred. In addition, Formula (2-1)-Formula (2-18) represent only the side chain group containing the terminal oxygen atom of the (meth) acrylic acid of Formula (2).

As the monomer for generating the repeating unit (II), for example, a (meth) acrylic acid derivative corresponding to the above formula (2) is preferably exemplified.
The repeating unit (II) is usually 20 to 80 mol%, preferably 30 to 70 mol%, assuming that all repeating units constituting the resin are 100 mol%. If the amount is less than 20 mol%, the shrinkage dimension does not increase, and if it exceeds 80 mol%, the solubility in the developer deteriorates.
In addition, the content of silicon atoms including the repeating unit (II) is preferably 2 to 50 mol% when the total repeating units constituting the resin are 100 mol%. If it is less than 2 mol%, the etching resistance in the etching process will be insufficient, and if it exceeds 50 mol%, the solubility of the composition in the developer will deteriorate.

The resin that can be used in the present invention is at least one selected from the repeating unit represented by the above formula (3) and the repeating unit represented by the above formula (4) together with the above repeating unit (I) and repeating unit (II). One repeating unit (III) can be included.
In the above formula (3), preferred examples of the group represented by R ⁵ include methylene group, ethylene group, propylene group such as 1,3-propylene group and 1,2-propylene group, tetramethylene group, pentamethylene. Group, hexamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-straight chain or branched alkylene group such as butylene group; 1,3-cyclobutylene group cyclobutylene group such as, 1,3-cyclopentylene cyclopentylene groups such as alkylene groups A monocyclic hydrocarbon group such as a cycloalkylene group having 4 to 10 carbon atoms such as a cyclohexylene group such as a 1,4-cyclohexylene group, a cyclooctylene group such as a 1,5-cyclooctylene group; 4-norbol 2-4 cyclic hydrocarbons having 4 to 12 carbon atoms, such as a norbornylene group such as a len group and a 2,5-norbornylene group, an adamantylene group such as a 1,5-adamantylene group and a 2,6-adamantylene group A crosslinked cyclic hydrocarbon group such as a cyclic group; a divalent group derived from an alkylene glycol having 1 to 10 carbon atoms such as ethylene glycol and propylene glycol; an alkylene ester having 1 to 10 carbon atoms such as ethylene ester and propylene ester; Examples thereof include a derived divalent group. Of these, a hydrocarbon group containing 2,5-norbornylene group, an ethylene group, and a propylene group are more preferable.

When R ⁵ in the above formula (3) is a divalent alicyclic hydrocarbon group, the divalent alicyclic hydrocarbon group and a bistrifluoromethyl-hydroxymethyl group (—C (CF ₃₎ between ₂ OH), it is preferable that the alkylene group having 1 to 4 carbon atoms is introduced as a spacer.

Preferable examples of the monomer (hereinafter also referred to as “monomer (3)”) that generates the repeating unit (3) include (meth) acrylic acid (1,1,1-trifluoro-2-trifluoro). Methyl-2-hydroxy-3-propyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1 , 1,1-trifluoro-2-trifluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4 -Pentyl) ester, (meth) acrylic acid 2-((5- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl) bicyclo [2.2.1 ] Heptyl Ester, (meth) 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. The polymer may contain only one type of repeating unit (3), or may contain two or more types of repeating units (3).

  The proportion of the repeating unit (3) contained in the polymer is preferably 0 to 70 mol%, more preferably 10 to 50 mol%, in 100 mol% of all repeating units.

In the above formula (4), R ⁶ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, a linear or branched alkoxyl group having 1 to 8 carbon atoms, or A benzyloxyl group, a tert-butoxycarbonyl group or a tert-butyldimethylsiloxyl group; R ⁶ in the above formula (4) is preferably a tert-butyl group, an acetoxy group, or a 1-ethoxyethoxy group, and more preferably a tert-butyl group. Moreover, it is preferable that the monomer which produces | generates a repeating unit (4) is a styrene derivative which has a specific functional group which can be converted into a phenolic hydroxyl group after copolymerization. Specific examples of such a styrene derivative having a specific functional group include p-acetoxystyrene, α-methyl-p-acetoxystyrene, and p-tert-butoxystyrene. These styrene derivatives can be used alone or in combination of two or more. In addition, after copolymerizing these styrene derivatives, if it hydrolyzes using hydrochloric acid etc., a specific functional group can be easily converted into a phenolic hydroxyl group.

  The proportion of the repeating unit (4) contained in the polymer is preferably 0 to 65 mol%, more preferably 10 to 50 mol%, in 100 mol% of all repeating units.

The resin that can be used in the present invention can contain other repeating units. Examples of the monomer capable of generating other repeating units include a monomer containing an alcoholic hydroxyl group and a monomer containing a hydroxyl group derived from an organic acid such as a carboxylic acid.
Monomers containing alcoholic hydroxyl groups include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, glycerol mono Hydroxyalkyl (meth) acrylates such as methacrylate can be exemplified, and 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferable. These monomers can be used alone or in combination of two or more.
The repeating unit derived from a monomer containing an alcoholic hydroxyl group is usually 0 to 40 mol%, preferably 5 to 30 mol%, based on 100 mol% of all repeating units constituting the resin.

Examples of the monomer containing a hydroxyl group derived from an organic acid such as carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, 2-succinoloylethyl (meth) acrylate, 2-malenoylethyl (meth) acrylate, 2 -Hexahydrophthaloylethyl (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate, monohydroxyethyl acrylate phthalate, acrylic acid dimer, 2-hydroxy-3-phenoxypropyl acrylate, t-butoxy methacrylate, t-butyl acrylate Monocarboxylic acids such as: (meth) acrylic acid derivatives having a carboxyl group such as dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid, and the like. Or 2 It can be used in combination or more. As a commercially available product of ω-carboxy-polycaprolactone monoacrylate, for example, Aronix M-5300 manufactured by Toagosei Co., Ltd., and as a commercially available product of acrylic acid dimer, for example, Aronix M-5600 manufactured by the same company, 2-hydroxy Examples of commercially available products of -3-phenoxypropyl acrylate include Aronix M-5700 manufactured by the same company.
Among these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloylethyl methacrylate are preferable.
The repeating unit derived from a monomer containing a hydroxyl group derived from carboxylic acid is usually 0 to 60 mol%, preferably 10 to 50 mol%, based on 100 mol% of all repeating units constituting the resin.

The above resin, for example, using a mixture of monomers, radical polymerization initiators such as hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, and the presence of a chain transfer agent if necessary Then, it can be produced by polymerization in an appropriate 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 resin preferably has a high purity, and not only the content of impurities such as halogen and metal is low, but the residual monomer and oligomer components are not more than predetermined values, for example, 0.1% by mass or less by HPLC analysis, etc. It is preferable that As a result, not only can the process stability, pattern shape, etc. of the resin composition for fine pattern formation of the present invention containing a resin be further improved, but there is no change over time such as foreign matter in liquid or sensitivity. A resin composition can be provided.
The following method is mentioned as a purification method of resin 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 resin thus obtained is usually 1,000 to 500,000, preferably 1,000 to 50,000, particularly preferably 1,000 to 20,000 in terms of polystyrene by gel permeation chromatography. It is. 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.

式（５）において、Ａ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価の環状炭化水素基を表し、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価の環状炭化水素基を表し、ｐは２〜４の整数、ｑは０または１を表す。
式（５）におけるＡおよびＤで表される炭素数２〜１０の直鎖状もしくは分岐状のアルキレン基としては、エチレン基、１，３−プロピレン基もしくは１，２−プロピレン基などのプロピレン基、テトラメチレン基、ペンタメチレン基、ヘキサメチレン基等が挙げられる。
また、炭素数３〜２０の２価の環状炭化水素基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基、シクロヘチル基、シクロオクチル基、１，４−ノルボルニレン基もしくは２，５−ノルボルニレン基などのノルボルニレン基、１，５−アダマンチレン基、２，６−アダマンチレン基などのアダマンチレン基等が挙げられる。
式（５）におけるＥで表される炭素数１〜１０の直鎖状もしくは分岐状のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、へキシル基、イソプロピル基、イソブチル基等が挙げられる。
ｍは２〜４の整数、好ましくは２であり、ｎは０または１、好ましくは１である。
好ましい架橋成分Ｉとしては、１，２−ベンゼンジカルボン酸ビス［（３−エチル−３−オキセタニル)メチル］エステル、１，４−ベンゼンジカルボン酸ビス［（３−エチル−３−オキセタニル)メチル］エステル、イソフタル酸ビス［（３−エチル−３−オキセタニル)メチル］エステルが好ましい。
上述した架橋成分Ｉは、単独であるいは２種以上を組み合わせて使用することができる。 In the resin composition for forming a fine pattern of the present invention, as a crosslinking agent for crosslinking the resin, a compound having two or more cyclic ethers represented by the following formula (5) (hereinafter referred to as “crosslinking component I”) It is preferable to contain.

In Formula (5), A 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 cyclic carbonization having 3 to 20 carbon atoms. Represents a hydrogen group, E represents a linear or branched alkyl group having 1 to 10 carbon atoms, a monovalent cyclic hydrocarbon group having 3 to 20 carbon atoms, p is an integer of 2 to 4, and q is 0 Or 1 is represented.
Examples of the linear or branched alkylene group having 2 to 10 carbon atoms represented by A and D in the formula (5) include a propylene group such as an ethylene group, a 1,3-propylene group, or a 1,2-propylene group. , Tetramethylene group, pentamethylene group, hexamethylene group and the like.
Examples of the divalent cyclic hydrocarbon group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexyl group, a cyclooctyl group, a 1,4-norbornylene group, and a 2,5-norbornylene group. Examples thereof include a norbornylene group such as a group, an adamantylene group such as a 1,5-adamantylene group, and a 2,6-adamantylene group.
Examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by E in the formula (5) 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.
m is an integer of 2 to 4, preferably 2, and n 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 Isophthalic acid bis [(3-ethyl-3-oxetanyl) methyl] ester is preferred.
The above-mentioned crosslinking component I can be used alone or in combination of two or more.

式（６）において、Ｒ⁷およびＲ⁸は、水素原子、または下記式（７）で表される基を表し、Ｒ⁷およびＲ⁸の少なくとも１つは下記式（７）で表される基である。

式（７）におけるＲ⁹およびＲ¹⁰は炭素数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、Ｒ⁹とＲ¹⁰とが互いに連結した炭素数２〜１０の環を表し、Ｒ¹¹は炭素数１〜６のアルキル基を表す。 The crosslinking agent used in the present invention may contain a compound having a group represented by the following formula (6) (hereinafter referred to as “crosslinking component II”) in the crosslinking component I.

In the formula (6), R ⁷ and R ⁸ represent a hydrogen atom or a group represented by the following formula (7), and at least one of R ⁷ and R ⁸ is a group represented by the following formula (7). It is.

R ⁹ and R ¹⁰ in Formula (7) are an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or a ring having 2 to 10 carbon atoms in which R ⁹ and R ¹⁰ are connected to each other. R ¹¹ represents an alkyl group having 1 to 6 carbon atoms.

The compound represented by formula (6) (crosslinking component 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 is a (poly) methylolated melamine, (poly) methylolated 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, one of R ⁷ and R ⁸ in Formula 6 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.

The crosslinking agent functions as a crosslinking agent (curing component) in which the above-described resin and / or crosslinking agent 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. Moreover, the crosslinking component I is 1-100 mass parts among all the crosslinking components, Preferably it is 5-90 mass parts.
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 hydroxyl group-containing resin and the crosslinking agent is less than 0.1% by mass, the coating film may be too thin, and the film may be cut off in the pattern-etched portion. There is a possibility that it cannot be embedded in the pattern.

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, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1- Butanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3 -Methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 1-heptanol, 2- Examples include heptanol, 2-methyl-2-heptanol, 2-methyl-3-heptanol, 1-butanol, 2-butano Le, 4-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 hydroxyl group-containing 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.

ｐ−ヒドロキシメタクリルアニリド（ｍ−１）４１．６４ｇ、上記単量体（ｍ−２）を５８．３６ｇ、アゾビスイソブチロニトリル８．４９ｇをイソプロパノール（ＩＰＡ）３００ｇに溶解し、還流条件（８２℃）にて６時間重合反応を行なった。反応容器を流水にて冷却した後、重合溶液に対して酢酸エチル２００ｇ、ＩＰＡ１４０ｇ、メタノール１４０ｇを加えて均一化し、そこに水を６００ｇ加えて１時間静置した。下層に沈降した粘性のポリマーを回収し５０℃の温度にて真空乾燥した。Ｍｗ１４，０００、Ｍｗ／Ｍｎ２．４５で、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−２）由来の繰り返し単位］＝４５．４/５４．６（モル％）、Ｓｉ含有率５．６（モル％）からなる重合体を得た。この重合体を樹脂Ｐ−１とする。なお、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−２）由来の繰り返し単位］は、¹³Ｃ ＮＭＲの測定結果より算出し、Ｓｉ含有率は、Ｓｉを含有する単量体中のＳｉの含有モル率を化学式から算出し、その値をもとに樹脂中における実組成のモル量から換算した値とした。以降、重合体における各単量体由来の繰り返し単位の含有率およびＳｉ含有率は実施例１と同様に算出したものとする。
樹脂Ｐ−１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。 The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited to these examples. Hereinafter, synthetic examples of resins used in the examples and comparative examples will be described.
Example 1

41.64 g of p-hydroxymethacrylanilide (m-1), 58.36 g of the monomer (m-2), and 8.49 g of azobisisobutyronitrile were dissolved in 300 g of isopropanol (IPA), and reflux conditions ( (82 ° C.) 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. Mw 14,000, Mw / Mn 2.45, [Repeating unit derived from monomer (m-1) / Repeating unit derived from monomer (m-2)] = 45.4 / 54.6 (mol%) A polymer having a Si content of 5.6 (mol%) was obtained. This polymer is designated as resin P-1. [Repeating unit derived from monomer (m-1) / Repeating unit derived from monomer (m-2)] was calculated from the measurement result of ¹³ C NMR, and the Si content contains Si. The mole fraction of Si in the monomer was calculated from the chemical formula, and based on that value, the value was converted from the molar amount of the actual composition in the resin. Hereinafter, the content of the repeating unit derived from each monomer and the Si content in the polymer are calculated in the same manner as in Example 1.
The measurement of Mw and Mn of the resin P-1 was performed using a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corp. Measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions.

ｐ−ヒドロキシメタクリルアニリド（ｍ−１）５７．３９ｇ、上記単量体（ｍ−３）４２．６１ｇ、アゾビスイソブチロニトリル７．０９ｇをイソプロパノール（ＩＰＡ）３００ｇに溶解し、還流条件（８２℃）にて６時間重合反応を行なった。反応容器を流水にて冷却した後、重合溶液に対して酢酸エチル２００ｇ、ＩＰＡ１４０ｇ、メタノール１４０ｇを加えて均一化し、そこに水を６００ｇ加えて１時間静置した。下層に沈降した粘性のポリマーを回収し５０℃の温度にて真空乾燥した。実施例１と同様にしてＭｗおよびＭｎ等を測定した結果、Ｍｗ８，３００、Ｍｗ／Ｍｎ１．３６、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−３）由来の繰り返し単位］＝７５．４/２４．６（モル％）、Ｓｉ含有率７．１モル％からなる重合体を得た。この重合体を樹脂Ｐ−２とする。 Example 2

57.39 g of p-hydroxymethacrylanilide (m-1), 42.61 g of the above monomer (m-3) and 7.09 g of azobisisobutyronitrile were dissolved in 300 g of isopropanol (IPA), and the reflux conditions (82 ) 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. As a result of measuring Mw, Mn and the like in the same manner as in Example 1, Mw8,300, Mw / Mn1.36, [repeating unit derived from monomer (m-1) / derived from monomer (m-3) Repeating unit] = 75.4 / 24.6 (mol%), a polymer having an Si content of 7.1 mol% was obtained. This polymer is designated as resin P-2.

ｐ−ヒドロキシメタクリルアニリド（ｍ−１）６２．３８ｇ、上記単量体（ｍ−４）３７．６２ｇ、アゾビスイソブチロニトリル７．７１ｇをイソプロパノール（ＩＰＡ）３００ｇに溶解し、還流条件（８２℃）にて６時間重合反応を行なった。反応容器を流水にて冷却した後、重合溶液に対して酢酸エチル２００ｇ、ＩＰＡ１４０ｇ、メタノール１４０ｇを加えて均一化し、そこに水を６００ｇ加えて１時間静置した。下層に沈降した粘性のポリマーを回収し５０℃の温度にて真空乾燥した。実施例１と同様にしてＭｗおよびＭｎ等を測定した結果、Ｍｗ８，５００、Ｍｗ／Ｍｎ１．４０、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−４）由来の繰り返し単位］＝７４．４/２５．６（モル％）、Ｓｉ含有率６．７モル％からなる重合体を得た。この重合体を樹脂Ｐ−３とする。 Example 3

62.38 g of p-hydroxymethacrylanilide (m-1), 37.62 g of the above monomer (m-4) and 7.71 g of azobisisobutyronitrile were dissolved in 300 g of isopropanol (IPA), and reflux conditions (82 ) 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. As a result of measuring Mw, Mn and the like in the same manner as in Example 1, Mw 8,500, Mw / Mn 1.40, [repeating unit derived from monomer (m-1) / derived from monomer (m-4) Repeating unit] = 74.4 / 25.6 (mol%), a polymer having an Si content of 6.7 mol% was obtained. This polymer is indicated as a resin P-3.

ｐ−ヒドロキシメタクリルアニリド（ｍ−１）３８．２２ｇ、上記単量体（ｍ−３）３８．７０ｇ、上記単量体（ｍ−５）２３．０７ｇ、アゾビスイソブチロニトリル６．４４ｇをイソプロパノール（ＩＰＡ）３００ｇに溶解し、還流条件（８２℃）にて６時間重合反応を行なった。反応容器を流水にて冷却した後、重合溶液に対して酢酸エチル２００ｇ、ＩＰＡ１４０ｇ、メタノール１４０ｇを加えて均一化し、そこに水を６００ｇ加えて１時間静置した。下層に沈降した粘性のポリマーを回収し５０℃の温度にて真空乾燥した。実施例１と同様にしてＭｗおよびＭｎ等を測定した結果、Ｍｗ８，６００、Ｍｗ／Ｍｎ１．４５、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−３）由来の繰り返し単位／単量体（ｍ−５）由来の繰り返し単位］＝５４．３/２５．６/２０．１（モル％）、Ｓｉ含有率５．７モル％からなる重合体を得た。この重合体を樹脂Ｐ−４とする。 Example 4

38.22 g of p-hydroxymethacrylanilide (m-1), 38.70 g of the monomer (m-3), 23.07 g of the monomer (m-5), 6.44 g of azobisisobutyronitrile. It melt | dissolved in 300 g of isopropanol (IPA), and the polymerization reaction was performed on the recirculation | reflux conditions (82 degreeC) for 6 hours. After cooling the reaction vessel with running water, 200 g of ethyl acetate, 140 g of IPA and 140 g of methanol were added to 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. As a result of measuring Mw, Mn, and the like in the same manner as in Example 1, Mw 8,600, Mw / Mn 1.45, [repeating unit derived from monomer (m-1) / derived from monomer (m-3) Repeating unit / repeating unit derived from monomer (m-5)] = 54.3 / 25.6 / 20.1 (mol%), and a polymer having an Si content of 5.7 mol% was obtained. This polymer is designated as resin P-4.

ｐ−ヒドロキシメタクリルアニリド（ｍ−１）４９．７５ｇ、上記単量体（ｍ−３）４２．６３ｇ、上記単量体（ｍ−６）７．６１ｇ、アゾビスイソブチロニトリル７．０９ｇをイソプロパノール（ＩＰＡ）３００ｇに溶解し、還流条件（８２℃）にて６時間重合反応を行なった。反応容器を流水にて冷却した後、重合溶液に対して酢酸エチル２００ｇ、ＩＰＡ１４０ｇ、メタノール１４０ｇを加えて均一化し、そこに水を６００ｇ加えて１時間静置した。下層に沈降した粘性のポリマーを回収し５０℃の温度にて真空乾燥した。実施例１と同様にしてＭｗおよびＭｎ等を測定した結果、Ｍｗ８，０００、Ｍｗ／Ｍｎ１．４２、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−３）由来の繰り返し単位／単量体（ｍ−６）由来の繰り返し単位］＝６４．５/２５．０/１０．５（モル％）、Ｓｉ含有率７．１モル％からなる重合体を得た。この重合体を樹脂Ｐ−５とする。 Example 5

49.75 g of p-hydroxymethacrylanilide (m-1), 42.63 g of the monomer (m-3), 7.61 g of the monomer (m-6), and 7.09 g of azobisisobutyronitrile. It melt | dissolved in 300 g of isopropanol (IPA), and the polymerization reaction was performed on the recirculation | reflux conditions (82 degreeC) for 6 hours. After cooling the reaction vessel with running water, 200 g of ethyl acetate, 140 g of IPA and 140 g of methanol were added to 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. As a result of measuring Mw, Mn, and the like in the same manner as in Example 1, Mw 8,000, Mw / Mn 1.42, [repeating unit derived from monomer (m-1) / derived from monomer (m-3) Repeating unit / repeating unit derived from monomer (m-6)] = 64.5 / 25.0 / 10.5 (mol%) and a Si content of 7.1 mol% were obtained. This polymer is indicated as a resin P-5.

ｐ−ヒドロキシメタクリルアニリド（ｍ−１）５０．１３ｇ、上記単量体（ｍ−６）４９．８７ｇ、アゾビスイソブチロニトリル１０．２２ｇをイソプロパノール（ＩＰＡ）３００ｇに溶解し、還流条件（８２℃）にて６時間重合反応を行なった。反応容器を流水にて冷却した後、重合溶液に対して酢酸エチル２００ｇ、ＩＰＡ１４０ｇ、メタノール１４０ｇを加えて均一化し、そこに水を６００ｇ加えて１時間静置した。下層に沈降した粘性のポリマーを回収し５０℃の温度にて真空乾燥した。実施例１と同様にしてＭｗおよびＭｎ等を測定した結果、Ｍｗ６，７００、Ｍｗ／Ｍｎ１．５６、［単量体（ｍ−１）由来の繰り返し単位/単量体（ｍ−６）由来の繰り返し単位］＝５０．５/４９．５（モル％）からなる重合体を得た。この重合体を樹脂Ｐ−６とする。 Comparative Example 1

50.13 g of p-hydroxymethacrylanilide (m-1), 49.87 g of the above monomer (m-6) and 10.22 g of azobisisobutyronitrile were dissolved in 300 g of isopropanol (IPA), and reflux conditions (82 ) 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. As a result of measuring Mw, Mn and the like in the same manner as in Example 1, Mw6,700, Mw / Mn1.56, [repeat unit derived from monomer (m-1) / derived from monomer (m-6) A polymer comprising repeating units] = 50.5 / 49.5 (mol%) was obtained. This polymer is indicated as a resin P-6.

Examples 6 to 15 and Comparative Example 2
After adding a resin, a crosslinking agent, an alcohol solvent, and other additives at the ratio shown in Table 1, the mixture was stirred for 3 hours and then filtered 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)
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.

In the examples shown in Table 1 for the evaluation substrate with a resist pattern, the resin composition for forming a fine pattern 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 ultrapure 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 (6)

A resin composition for forming a fine pattern for refining a resist pattern formed on a substrate, comprising a resin, a crosslinking agent that crosslinks the resin, and a solvent,
A resin for forming a fine pattern, wherein the resin includes a repeating unit (I) having a hydroxyl group derived from phenols in a side chain and a repeating unit (II) having a group containing a silicon atom in the side chain. Composition. The said repeating unit (I) is a repeating unit represented by following formula (1), The resin composition for fine pattern formation of Claim 1 characterized by the above-mentioned.

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond, a methylene group, a chain or branched alkylene group having 2 to 5 carbon atoms, an —NH— group, —O—; Group, -COO- group, or -CONH- group, each R ³ independently represents a hydrogen atom, a saturated chain hydrocarbon group having 1 to 6 carbon atoms, a monocyclic hydrocarbon group having 3 to 8 carbon atoms, Alternatively, it represents a polycyclic hydrocarbon group having 7 to 10 carbon atoms, and m = 1 to 2 and n = 0 to 2. The said repeating unit (II) is a repeating unit represented by following formula (2), The resin composition for fine pattern formation of Claim 1 or Claim 2 characterized by the above-mentioned.

(In Formula (2), R ¹ represents a hydrogen atom or a methyl group, X is a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a divalent alicyclic ring having 3 to 12 carbon atoms. R ⁴ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or —O—Si—. R ′ ₃ represents a group, and each R ′ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms.) The said resin contains at least 1 repeating unit (III) chosen from the repeating unit represented by following formula (3) and the repeating unit represented by following formula (4), Claim 1 characterized by the above-mentioned. Item 4. The resin composition for forming a fine pattern according to Item 2 or Item 3.

(In Formula (3), R ^{1 ′} represents a hydrogen atom, a methyl group or a trifluoromethyl group, R ⁵ represents a single bond, a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, carbon A divalent alicyclic hydrocarbon group of 4 to 12 or a divalent group derived from alkylene glycol or alkylene ester,
In the formula (4), R ⁶ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, a linear or branched alkoxyl group having 1 to 8 carbon atoms, a benzyloxyl group, tert -Represents a butoxycarbonyl group or a tert-butyldimethylsiloxyl group. )   5. The repeating unit (II) according to any one of claims 1 to 4, wherein the repeating unit (II) is contained in an amount of 20 to 80 mol%, based on 100 mol% of all repeating units constituting the resin. A resin composition for forming a fine pattern.   A pattern forming step of forming a resist pattern on the substrate, a coating step of coating the resin composition for forming a fine pattern according to any one of claims 1 to 5 on the resist pattern, and after the coating step The fine pattern formation method including the process of heat-processing the board | substrate of this, the process developed with alkaline aqueous solution, and the process of an etching process.

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