JP2009265505A - Pattern formation method and resin composition for fine pattern formation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern formation method capable of forming a fine pattern simply and effectively. <P>SOLUTION: The pattern formation method for forming a prescribed pattern on a substrate includes: (1) a step of obtaining a first resist pattern formed with part of the prescribed pattern; (2) a step of forming a mask layer for a first etching, which is provided with a first resist pattern and a first coating layer coating the first resist pattern; (3) a step of etching the substrate; (4) a step of obtaining a second resist pattern, in which at least part of the pattern of the remaining of the prescribed pattern is formed; (5) a step of forming a mask layer for a second etching provided with a second resist pattern and a second coating layer for coating the second resist pattern; (6) and a step of performing further etching process. The processes (4) to (6) are repeated one time or more in this order. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pattern forming method and a resin composition for forming a fine pattern. More specifically, the present invention relates to a pattern forming method capable of easily and efficiently forming a finer pattern, and a resin composition for forming a fine pattern used in this pattern forming method.

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

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

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

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

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

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

  The technique proposed in Non-Patent Document 1 forms a 32 nm space with a pitch of 1: 3, and then processes it by etching. A 32 nm space with a pitch is formed and processed again by etching. As a result, a 32 nm line having a pitch of 1: 1 is finally formed.

  However, even with the technique proposed in Non-Patent Document 1, it is difficult to easily and efficiently form a 32 nm space pattern with a finer pattern. Further, Non-Patent Document 1 does not propose specific and practical methods and materials. Therefore, at present, no concrete and practical method or material for forming a 32 nm space pattern simply and efficiently with a finer pattern has been proposed yet.

  Therefore, development of a pattern forming method capable of easily and efficiently forming a finer pattern and a resin composition for forming a fine pattern used in this pattern forming method is eagerly desired.

  The present invention has been made to solve the above-described problems of the prior art, and a pattern forming method capable of easily and efficiently forming a finer pattern, and this pattern formation. A resin composition for forming a fine pattern used in the method is provided.

  Specifically, the present invention provides the following pattern forming method and resin composition for forming a fine pattern.

[1] A pattern forming method for forming a predetermined pattern on a substrate, (1) forming and forming a first resist film on the substrate using a first positive radiation sensitive resin composition A step of selectively exposing the developed first resist film and then developing to obtain a first resist pattern in which a pattern corresponding to a part of the predetermined pattern is formed; and (2) the first The first resist pattern is coated with the fine pattern forming resin composition, baked, washed, and the first resist pattern and the first resist pattern are coated with the fine pattern forming resin composition. Forming a first etching mask layer comprising a coating layer on the substrate; (3) etching the substrate using the first etching mask layer as a mask; After the etching treatment, the first etching mask layer is removed to obtain a primary treatment substrate, and a second resist is formed on the obtained primary treatment substrate using a second positive radiation sensitive resin composition. Forming a film, selectively exposing the second resist film, and developing to obtain a second resist pattern in which a pattern corresponding to at least a part of the remaining portion of the predetermined pattern is formed; And (5) applying the fine pattern-forming resin composition to the second resist pattern, baking, and washing the resin to form the second resist pattern and the second resist pattern. Forming a second etching mask layer on the primary substrate with a second coating layer coated with the composition; and (6) using the second etching mask layer as a mask. And a step of etching the primary processing substrate, and obtaining the predetermined pattern by repeating the steps (4) to (6) one or more times in order.

[2] The pattern formation according to [1], wherein the first resist pattern and the resist pattern formed on the second resist pattern are line and space patterns each having a line portion and a space portion. Method.

[3] The pattern forming method according to [1] or [2], wherein the predetermined pattern formed on the substrate has a hole pattern.

[4] A resin composition for forming a fine pattern, which is used in the pattern forming method according to any one of [1] to [3].

[5] The resin composition for forming a fine pattern according to the above [4], comprising a resin, a crosslinking component that reacts with the resin, and an alcohol solvent.

  Since the pattern formation method of the present invention is a method for obtaining a predetermined pattern by repeating the steps (4) to (6) one or more times in order, having the above steps (1) to (6). There is an effect that the pattern can be easily and efficiently formed.

  The resin composition for forming a fine pattern of the present invention is used in the pattern forming method of the present invention, and is a material that can be suitably used to form a finer pattern easily and efficiently. There is an effect that there is.

  Hereinafter, the best mode for carrying out the present invention will be described, but the present invention is not limited to the following embodiment. That is, it is understood that modifications and improvements as appropriate to the following embodiments are also within the scope of the present invention based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.

[1] Pattern formation method:
One embodiment of the pattern forming method of the present invention is a pattern forming method for forming a predetermined pattern on a substrate, and (1) a first on a substrate using a first positive radiation sensitive resin composition. The first resist film thus formed is selectively exposed and then developed to obtain a first resist pattern in which a pattern corresponding to a part of a predetermined pattern is formed (hereinafter referred to as a resist pattern). , And (2) apply the fine pattern-forming resin composition to the first resist pattern, bake, and wash to obtain the first resist pattern and this A step of forming a first etching mask layer on a substrate comprising a first coating layer obtained by coating the first resist pattern with a resin composition for forming a fine pattern (hereinafter referred to as “(2) step”) And (3) first Using the etching mask layer as a mask, a step of etching the substrate (hereinafter sometimes referred to as “(3) step”), and (4) removing the first etching mask layer after the etching treatment After obtaining the treated substrate, forming the second resist film on the obtained primary treated substrate using the second positive radiation sensitive resin composition, and selectively exposing the second resist film, A step of developing to obtain a second resist pattern in which a pattern corresponding to at least a part of the remaining portion of the predetermined pattern is formed (hereinafter may be referred to as “(4) step”); (5) A second coating in which a fine pattern forming resin composition is applied to the second resist pattern, baked, and then washed to cover the second resist pattern and the second resist pattern with the fine pattern forming resin composition. And (6) using the second etching mask layer as a mask (hereinafter, may be referred to as “(5) step”). And a step of etching the primary processing substrate (hereinafter may be referred to as “(6) step”), and repeating the steps (4) to (6) one or more times in order To get. As described above, the above steps (1) to (6) are included, and the steps (4) to (6) are repeated one or more times in order, whereby a finer pattern can be easily and efficiently formed on the substrate. Can be formed.

  In the pattern forming method of the present embodiment, the resist pattern formed on the first resist pattern and the second resist pattern is preferably a line-and-space pattern having a line portion and a space portion, respectively.

  The predetermined pattern formed on the substrate can be selected as appropriate, but preferably has a hole pattern.

[1-1] Step (1):
In the step (1) of the pattern forming method of the present embodiment, the first resist film is formed on the substrate using the first positive radiation sensitive resin composition, and the formed first resist film is used as the first resist film. This is a step of obtaining a first resist pattern in which a part of a predetermined pattern is formed after selective exposure and development.

[1-1-1] First positive radiation-sensitive resin composition:
As the first positive radiation sensitive resin composition used in the step (1), a conventionally known positive radiation sensitive resin composition can be used. For example, the first positive radiation sensitive resin composition includes an acid generator and an acid dissociable group-containing resin having an acid dissociable group that is dissociated by the action of an acid generated from the acid generator. In the first resist film formed by the first positive radiation sensitive resin composition, the selectively exposed portion (exposed portion) is highly soluble in an alkaline developer, and the exposed portion is It is dissolved and removed by an alkali developer.

  The first positive radiation sensitive resin composition preferably contains a resin having a repeating unit represented by the following general formula (1) and an acid generator.

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

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

Specific examples of the derivative of a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ² include a hydroxyl group; a carboxyl group; an oxo group (that is, ═O group); a hydroxymethyl group, 1- Hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl A hydroxyalkyl group having 1 to 4 carbon atoms such as a group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group A C 1-4 alkoxy group such as cyano group, cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyano The group which has 1 or more types of substituents, such as C2-C5 cyanoalkyl groups, such as a butyl group, can be mentioned. Of these, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, and a cyanomethyl group are preferable.

Specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ² include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methyl group. A propyl group, a 1-methylpropyl group, a t-butyl group, etc. can be mentioned. Of these, a methyl group and an ethyl group are preferable.

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

In General Formulas (1a) to (1f), R ³ is independently a linear or branched alkyl group having 1 to 4 carbon atoms, and m is 0 or 1. Specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1- Examples thereof include a methylpropyl group and a t-butyl group. Of these, a methyl group and an ethyl group are preferable.

In the general formula (1), the part represented by “—COOC (R ² ) ₃ ” is a part that is dissociated by the action of an acid to form a carboxyl group and becomes an alkali-soluble part. This “alkali-soluble site” is a group that becomes an anion (alkali-soluble) by the action of an alkali. On the other hand, an “acid-dissociable group” is a group in which an alkali-soluble site is protected with a protecting group, and is a group that is not “alkali-soluble” until the protecting group is removed with an acid.

  The acid generator is not particularly limited as long as it is decomposed by exposure and generates an acid, and a conventionally known one can be used, but has a structure represented by the following general formula (2). It is preferable.

In general formula (2), R ⁴ is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched group having 1 to 10 carbon atoms. An alkoxyl group or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms is shown. R ⁵ is independently a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group, or an optionally substituted naphthyl group, Alternatively, two R ⁵ may be bonded to each other to form a divalent group having 2 to 10 carbon atoms. In addition, the formed bivalent group may be substituted. R ⁶ represents a linear or branched alkyl group or alkoxyl group having 1 to 10 carbon atoms, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. k is an integer of 0 to 2, and X ⁻ is a general formula: R ⁷ C _n F _2n SO ₃ ⁻ (wherein R ⁷ is a fluorine atom or an optionally substituted carbon atom having 1 to 12 carbon atoms. It is a hydrocarbon group, n is an integer of 1-10), q is an integer of 0-10.

  The first positive radiation sensitive resin composition preferably further contains an acid diffusion controller and a nitrogen-containing organic compound, and the first positive radiation sensitive resin composition contains an acid dissociable group. An acid dissociable group-containing resin having an acid, an acid generator, an acid diffusion controller, and a nitrogen-containing organic compound may be dissolved in a solvent. As the acid diffusion controller, the nitrogen-containing organic compound, and the solvent, conventionally known ones can be appropriately selected and used.

  In addition, the first positive-type radiation-sensitive resin composition can contain various additives such as a surfactant, a sensitizer, and an aliphatic additive as necessary.

[1-1-2] Substrate:
The substrate is used in the field of microfabrication represented by the manufacture of integrated circuit elements, and examples thereof include a silicon wafer, an oxide film wafer, and a nitride film wafer. In addition, this board | substrate may form the antireflection film, the topcoat, etc. on the surface, for example. The antireflection film is for maximizing the potential of the first resist film. For example, an organic or inorganic type film disclosed in Japanese Patent Publication No. 6-12252 may be used. it can.

  A conventionally well-known method can be employ | adopted for the formation method of a 1st resist film. For example, the first positive-type radiation-sensitive resin composition is applied onto a substrate by coating means such as spin coating, cast coating, roll coating, etc. to form a coating film, followed by pre-baking (PB). The first resist film can be formed by volatilizing the solvent in the film. Although the prebaking heating conditions are appropriately selected depending on the composition of the first resist film, it is preferably 30 to 200 ° C, more preferably 50 to 150 ° C.

  In this specification, “selectively exposing” means exposing a resist film (a first resist film and a second resist film) so that a part of a predetermined pattern is formed. The partial pattern to be formed is preferably a line and space pattern. For example, in FIG. 1, when forming a line and space pattern having five space portions, the first resist film is selectively exposed and developed so that two space portions are formed. In this example, a sheet-like first resist pattern 12 is formed on the substrate 11. FIG. 1 is a cross-sectional view of the substrate and the first resist pattern when the first resist pattern is formed on the substrate in the step (1) of the pattern forming method of the present embodiment.

  The exposure can be performed by irradiating light, for example, radiation, and the radiation includes visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, depending on the type of acid generator contained in the resist film. However, far ultraviolet rays typified by ArF excimer laser (wavelength 193 nm), KrF excimer laser (wavelength 248 nm) and the like are preferable, and ArF excimer laser (wavelength 193 nm) is particularly preferable. The exposure conditions such as the exposure amount are appropriately selected according to the composition of the resist film, the type of additive, and the like. Further, in the process, it is preferable to perform heat treatment (PEB) after exposure. This is because the dissociation reaction of the acid dissociable group in the acid dissociable group-containing resin can be smoothly advanced by this PEB. The heating condition in PEB is appropriately selected depending on the composition of the resin composition, but is preferably 30 to 200 ° C, and more preferably 50 to 170 ° C.

  Development can be performed by a conventionally known method. Examples of the developer that can be used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable.

  The concentration of the alkaline aqueous solution is preferably 10% by mass or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, the non-exposed portion may be easily dissolved in the developer. In addition, after developing using alkaline aqueous solution, generally it wash | cleans with water and dries.

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

  The addition amount of the organic solvent is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. If the added amount of the organic solvent is more than 100 parts by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed part increases. An appropriate amount of a surfactant or the like can be added to the developer.

  In this step, as described above, for example, as shown in FIG. 1, the first resist pattern 12 in which a part of a predetermined pattern is formed can be formed on the substrate 11.

[1-2] (2) Step:
In the step (2) of the pattern forming method of the present embodiment, the first resist pattern is coated with the resin composition for forming a fine pattern, baked, washed, and the first resist pattern and the first resist pattern. This is a step of forming a first etching mask layer including a first coating layer coated with a resist pattern on a substrate.

[1-2-1] Resin composition for forming a fine pattern:
The resin composition for forming a fine pattern used in the pattern forming method of the present embodiment forms a coating layer insoluble in a developing solution while being cured by reacting with the first resist pattern by baking. The resin composition for forming a fine pattern preferably contains a resin (hereinafter sometimes referred to as “resin for forming a fine pattern”), a crosslinking component that reacts with the resin, and an alcohol solvent.

[1-2-1a] Resin (resin for forming a fine pattern):
As the resin contained in the resin composition for forming a fine pattern, a resin containing a repeating unit derived from a monomer represented by the following general formula (3) (hereinafter simply referred to as “repeating unit (I)”) It is preferable that

In the general formula (3), R ⁸ , R ⁹ , and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group, or a phenyl group, A is a single bond, an oxygen atom, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, and B is a single bond or a divalent organic group having 1 to 20 carbon atoms.

In the general formula (3), R ¹¹ is preferably a linear or branched fluoroalkyl group having 1 to 8 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and at least one hydrogen atom More preferably, it is a linear or branched fluoroalkyl group having 1 to 4 carbon atoms in which the atom is substituted with a fluorine atom.

  Examples of the fluoroalkyl group having 1 to 8 carbon atoms include a difluoromethyl group, a perfluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1 , 2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1 , 2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoro (Ropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5 -Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1 , 2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group Perfluoropentylmethyl group, perfluorohexyl group, 2- (perfluoropentyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoroheptyl group , Perfluorohexylmethyl group, perfluoroheptyl 2- (perfluorohexyl) ethyl group, 1,1,2,2,3,3,4,4,5,5,6,6,7,7-tetradecafluorooctyl group, perfluoroheptylmethyl group Perfluorooctyl group, 2- (perfluoroheptyl) ethyl group, and the like.

  If the number of carbon atoms of the fluoroalkyl group becomes too large, the solubility in an alkaline aqueous solution is lowered, and among these, a perfluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group are preferable.

Examples of the alkyl group having 1 to ¹⁰ carbon atoms of R ⁸ , R ⁹ , and R ¹⁰ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, A decyl group etc. are mentioned. Among these, R ⁸ and R ¹⁰ are preferably hydrogen atoms, and R ⁹ is preferably a hydrogen atom or a methyl group.

  Examples of the divalent organic group having 1 to 20 carbon atoms of B include, for example, a saturated chain hydrocarbon group having 1 to 20 carbon atoms, a monocyclic hydrocarbon ring group having 1 to 8 carbon atoms, and 1 to 10 carbon atoms. And a polycyclic hydrocarbon ring group.

  Examples of the saturated chain hydrocarbon group having 1 to 20 carbon atoms of B include a propylene group such as a methylene group, an ethylene group, a 1,3-propylene group, and a 1,2-propylene group, a tetramethylene group, and a pentamethylene group. , Hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadeca Methylene group, octadecamethylene group, nonadecamethylene group, eicosamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group and the like.

  Examples of the monocyclic hydrocarbon ring group having 1 to 8 carbon atoms of B include, for example, a cyclobutylene group such as a 1,3-cyclobutylene group, a cyclopentylene group such as a 1,3-cyclopentylene group, Examples thereof include a cyclohexylene group such as a 1,4-cyclohexylene group, a cyclooctylene group such as a 1,5-cyclooctylene group, and the like.

  Examples of the polycyclic hydrocarbon ring group having 1 to 10 carbon atoms of B include, for example, norbornylene groups such as 1,4-norbornylene group and 2,5-norbornylene group, 1,5-adamantylene group, 2, And adamantylene group such as 6-adamantylene group.

  Specific examples of the compound represented by the general formula (3) include 2-((((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate and 2-(((trifluoromethyl) sulfonyl) amino). Ethyl-1-acrylate or a compound represented by the following formulas (3-1) to (3-6) is preferable.

  The content ratio of the repeating unit (I) is preferably from 0.1 to 30 mol%, more preferably from 8 to 12 mol%, based on all repeating units in the fine pattern forming resin. When the content is less than 0.1 mol%, after applying the resin composition for forming a fine pattern to the first resist pattern, baking and washing, insoluble matter remains at the bottom of the space portion. There is a risk that it is difficult to form a fine space pattern. On the other hand, if it exceeds 30 mol%, the shrinkage amount of the resin for forming a fine pattern is decreased, and a fine space pattern may not be formed.

  In addition to the above repeating unit (I), the fine pattern forming resin contains at least one hydroxyl group selected from the group consisting of alcohols, phenols and hydroxyl groups derived from carboxylic acids in the side chain (hereinafter referred to as “repeating unit”). , Which may be referred to as “repeating unit (II)”).

  The repeating unit (II) is copolymerized using a polymerizable unsaturated bond monomer having in the side chain at least one hydroxyl group selected from the group consisting of alcohols, phenols, and carboxylic acids. Can be obtained.

  Examples of the polymerizable unsaturated bond monomer having a hydroxyl group derived from alcohol in the side chain include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4 -Hydroxyalkyl (meth) acrylates such as hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and glycerol monomethacrylate. Among these, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferable. These monomers can be used alone or in combination of two or more.

  The content ratio of the repeating unit having a hydroxyl group derived from alcohol in the side chain is preferably 3 to 40 mol%, and preferably 5 to 30 mol%, based on all repeating units in the resin for forming a fine pattern. More preferably. If the content is less than 3 mol%, there are too few reactive sites with the crosslinking component described later, and it may be difficult to sufficiently cause pattern shrinkage. On the other hand, if it exceeds 40 mol%, there is a risk of swelling during filling and filling the pattern.

  Examples of the polymerizable unsaturated bond monomer having a hydroxyl group derived from phenol in the side chain 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 Examples include -methoxyphenol, 4-allyl-2,6-dimethoxyphenol, 4-allyloxy-2-hydroxybenzophenone, monomers represented by the following general formula (4) having an amide group in the molecule, and the like. . Among these, p-hydroxystyrene, α-methyl-p-hydroxystyrene, and a monomer represented by the following general formula (4) are preferable. These monomers can be used alone or in combination of two or more.

In the general formula (4), R ¹² and R ¹⁴ are a hydrogen atom or a methyl group, and R ¹³ is a linear or cyclic divalent hydrocarbon group.

Examples of R ¹³ include methylene group, ethylene group, propylene group (for example, 1,3-propylene group, 1,2-propylene group), tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octane group. Methylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group Methylene group, insalene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, Saturated chain such as 2-methyl-1,4-butylene group, ethylidene group, propylidene group, 2-propylidene group Hydrocarbon groups, cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, cyclohexylene groups such as 1,4-cyclohexylene groups, 1,5-cyclohexane Cyclooctylene groups such as octylene groups, monocyclic hydrocarbon ring groups such as cycloalkylene groups having 3 to 10 carbon atoms, norbornylene groups such as 1,4-norbornylene groups and 2,5-norbornylene groups, Examples thereof include a bridged cyclic hydrocarbon ring group such as a 2- to 4-cyclic hydrocarbon ring group having 4 to 30 carbon atoms such as an adamantylene group such as a 5-adamantylene group and a 2,6-adamantylene group. .

  As the monomer represented by the general formula (4), p-hydroxymethacrylanilide is preferable.

  The content ratio of the repeating unit derived from the monomer represented by the general formula (4) is preferably 30 to 90 mol% with respect to all the repeating units in the resin for forming a fine pattern, and 40 to 80 More preferably, it is mol%. When the content is less than 30 mol%, there are too few reactive sites with a crosslinking component described later, and it may be difficult to sufficiently cause pattern shrinkage. On the other hand, if it exceeds 90 mol%, there is a risk of swelling during filling and filling the pattern.

  Examples of the polymerizable unsaturated bond monomer having a hydroxyl group derived from a carboxylic acid in the side chain include acrylic acid, methacrylic acid, crotonic acid, 2-succinoloylethyl (meth) acrylate, and 2-malenoyl. Ethyl (meth) acrylate, 2-hexahydrophthaloylethyl (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate, phthalic acid monohydroxyethyl acrylate, acrylic acid dimer, 2-hydroxy-3-phenoxypropyl acrylate, t- Examples thereof include monocarboxylic acids such as butoxy methacrylate and t-butyl acrylate; (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. These monomers can be used alone or in combination of two or more. Among these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloylethyl methacrylate are preferable.

  Examples of commercially available products of ω-carboxy-polycaprolactone monoacrylate include “Aronix M-5300” manufactured by Toagosei Co., Ltd., and examples of commercially available products of acrylic acid dimer include those manufactured by Toagosei Co., Ltd. "Aronix M-5600" etc. can be mentioned, As a commercial item of 2-hydroxy-3-phenoxypropyl acrylate, "Aronix M-5700" by Toagosei Co., Ltd. etc. can be mentioned, for example.

  The content of the polymerizable unsaturated bond monomer having a hydroxyl group derived from a carboxylic acid in the side chain is preferably 5 to 60 mol% with respect to all repeating units in the resin for forming a fine pattern, More preferably, it is 10-50 mol%. When the content is less than 5 mol%, there are too few reaction sites with a crosslinking component described later, and it may be difficult to sufficiently cause pattern shrinkage. On the other hand, if it exceeds 60 mol%, there is a possibility that the pattern will swell during washing and fill the pattern.

  The repeating unit (II) can also be obtained by copolymerization using a monomer having a functional group that can be converted to a phenolic hydroxyl group (functional group-containing compound). Examples of such functional group-containing compounds include p-acetoxystyrene, α-methyl-p-acetoxystyrene, p-benzyloxystyrene, p-tert-butoxystyrene, p-tert-butoxycarbonyloxystyrene, p -Tert-butyldimethylsiloxystyrene etc. are mentioned. When these functional group-containing compounds are used, the resulting fine pattern-forming resin can be easily converted into phenolic hydroxyl groups by appropriate treatment, for example, hydrolysis using hydrochloric acid or the like. Can be converted. The repeating unit derived from the functional group-containing compound is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on all repeating units in the fine pattern forming resin.

  In addition to the above repeating units (I) and (II), the resin for forming a fine pattern may be represented by a repeating unit represented by the following general formula (5) (hereinafter simply referred to as “repeating unit (III)”). ).

In the general formula (5), R ¹⁵ 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.

Examples of R ¹⁵ include a tert-butyl group, an acetoxy group, a 1-ethoxyethoxy group, and a tert-butoxyl group. Among these, a tert-butoxyl group is preferable.

  The content ratio of the repeating unit (III) is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, based on all repeating units in the fine pattern forming resin. There exists a possibility that the shrinkage | contraction dimension of resin for fine pattern formation may not increase that the said content rate is less than 10 mol%. On the other hand, if it exceeds 60 mol%, the solubility of the fine pattern forming resin in the developer may be deteriorated.

  When the fine pattern forming resin has the repeating units (I) to (III), the content ratio of the repeating unit (II) is 37 to 87 mol% with respect to all the repeating units in the fine pattern forming resin. It is preferable that

  In addition to the repeating unit (I), the repeating unit (II), and the repeating unit (III), the fine pattern forming resin may contain other monomers in order to control the hydrophilicity and solubility of the fine pattern forming resin. It can further have a repeating unit derived from.

  The other monomer is a monomer other than the monomer for constituting the repeating unit (I), the repeating unit (II), and the repeating unit (III). For example, (meth) acrylic acid aryl esters, dicarboxylic acid diesters, nitrile group-containing polymerizable compounds, amide bond-containing polymerizable compounds, vinyls, allyls, chlorine-containing polymerizable compounds, conjugated diolefins, etc. Can be mentioned. Specifically, dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; (meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; aromatic vinyl such as vinyltoluene , Methacrylic acid esters such as t-butyl (meth) acrylate, 4,4,4-trifluoro-3-hydroxy-1-methyl-3-trifluoromethyl-1-butyl (meth) acrylate; acrylonitrile Nitrile group-containing polymerizable compounds such as methacrylonitrile; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; fatty acid vinyls such as vinyl acetate; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; -Butadiene, isoprene, 1, 4 It can be used conjugated diolefins dimethyl butadiene and the like. These compounds can be used alone or in combination of two or more.

  Resin for fine pattern formation, for example, using a radical polymerization initiator such as hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, etc., with a mixture of each monomer, chain transfer as necessary It can manufacture by superposing | polymerizing in a suitable solvent in presence of an agent.

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

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

  The fine pattern forming resin preferably has a high purity. Specifically, not only the content of impurities such as halogen and metal is low, but the remaining monomer and oligomer components are below a predetermined value, for example, 0.1% by mass by HPLC (high performance liquid chromatography) analysis. The following is preferable. This high purity not only can further improve the process stability, pattern shape, etc. of the resin composition for fine pattern formation, but also does not change over time such as foreign matter in liquid or sensitivity. A composition can be obtained.

  Examples of the method for refining the fine pattern forming resin include the following methods. First, as a method of removing impurities such as metals, a metal is chelated by washing the polymerization solution with an acidic aqueous solution such as oxalic acid or sulfonic acid, or by adsorbing the metal in the polymerization solution using a zeta potential filter. And the like. Next, methods for removing residual monomer and oligomer components below the specified value include water-washing and liquid-liquid extraction methods that remove residual monomer and oligomer components by combining appropriate solvents, and specific molecular weights. A purification method in the form of a solution such as ultrafiltration that extracts and removes only the following: a residual solution that removes residual monomers by coagulating the resin in the poor solvent by dropping the polymerization solution into the poor solvent Examples thereof include a precipitation method 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 for forming a fine pattern is preferably from 1,000 to 500,000, more preferably from 1,000 to 50,000, in terms of polystyrene by gel permeation chromatography. 1,000 to 20,000 is particularly preferable. If the weight average molecular weight (Mw) is less than 1,000, a uniform coating film may not be formed after coating. On the other hand, if it exceeds 500,000, it may be difficult to remove the resin for forming a fine pattern after curing with a developer.

[1-2-1b] Crosslinking component:
The resin for forming a fine pattern contains a crosslinking component that reacts with the resin, and acts as a curing component that reacts with the resin by the action of an acid. In addition, this crosslinking component may be a component that is cured by a reaction between the crosslinking components in addition to the reaction with the resin for forming a fine pattern.

  The crosslinking component includes a compound containing a group represented by the following general formula (6) (hereinafter sometimes referred to as “crosslinking component (I)”), a compound containing two or more cyclic ethers as a reactive group (hereinafter referred to as “crosslinking component (I)”). Or a mixture of “crosslinking component (I)” and “crosslinking component (II)”.

In the general formula (6), R ¹⁶ and R ¹⁷ are a hydrogen atom or a group represented by the following general formula (7), and at least one of R ¹⁶ and R ¹⁷ is represented by the following general formula (7). Group.

In the general formula (7), R ¹⁸ and R ¹⁹ are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 1 to 6 carbon atoms, or a carbon number 2 in which R ¹⁸ and R ¹⁹ are connected to each other. -10 ring, and R ²⁰ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

  The crosslinking component (I) is a compound having an imino group, a methylol group, a methoxymethyl group or the like as a functional group in the molecule. As the crosslinking component (I), for example, all or part of active methylol groups such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea are alkylated. Examples thereof include etherified nitrogen-containing compounds. Here, examples of the alkyl group include a methyl group, an ethyl group, a butyl group, or a mixture thereof. These may contain an oligomer component obtained by partially self-condensing them. Specific examples include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, and tetrabutoxymethylated glycoluril.

  Commercially available products of the crosslinking component (I) are all trade names, for example, Cymel 300, 301, 303, 350, 232, 235, 236, 238, 266, 267, 285. 1123, 1123-10, 1170, 370, 771, 272, 1172, 325, 327, 703, 712, 254, 253, 212, 1128, 701 202, 207 (manufactured by Nippon Cytec Co., Ltd.), Nicarak MW-30M, 30, 22, 24X, Nicarak MS-21, 11, 001, Nicarax MX-002, 730, 750 708, 706, 042, 035, 45, 410, 302, 202, Nicarak SM-651, 652, 653, 551, 45 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.

  Among these, Cymel 325, 327, 703, 712, 254, 253, 212, 1128, 701, 202, and 207, which are crosslinking components containing an imino group, are preferable.

  Examples of the crosslinking component (II) include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy. ) Cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4 '-Epoxy-6'-methylcyclohexanecarboxylate, methylene bis (3,4-epoxycyclohexane), di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylene bis (3,4-epoxycyclohexanecarboxylate), ε-caprolactone 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone Epoxycyclohexyl group-containing compounds such as modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate,

  Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, Hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol Diglycidyl ether, polypropylene glycol diglycidyl ethers,

  Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin; diglycidyl esters of aliphatic long-chain dibasic acids Monoglycidyl ethers of higher aliphatic alcohols; monoglycidyl ethers of polyether alcohols obtained by adding phenol, cresol, butylphenol or alkylene oxide to these; glycidyl esters of higher fatty acids,

  3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,3- (2-methylenyl) propanediylbis (oxymethylene)) bis- (3-ethyloxetane), 1 , 4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl- 3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether, triethyleneglycolbis (3-ethyl-3 -Oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, Licyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3-oxetanylmethoxy) butane 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane,

  Pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritoltetrakis (3-ethyl-3-oxetanylmethyl) ether,

  Caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanyl) Methyl) ether, ethylene oxide (EO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, propylene oxide (PO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol F (3-ethyl 3 such oxetanylmethyl) oxetane compound having two or more oxetane rings in the molecule, such as ether. The above-mentioned crosslinking components can be used alone or in combination of two or more.

  Among these, 1,6-hexanediol diglycidyl ether and dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether are preferable.

  The content of the crosslinking component in the resin composition for forming a fine pattern is preferably 1 to 100 parts by weight, and more preferably 5 to 70 parts by weight with respect to 100 parts by weight of the resin for forming a fine pattern. . When the content is less than 1 part by mass, curing may be insufficient and pattern shrinkage may not occur. On the other hand, if it exceeds 100 parts by mass, curing may proceed excessively and the pattern may be buried.

[1-2-1c] Alcohol solvent:
When the alcohol solvent contained in the resin composition for forming a fine pattern sufficiently dissolves the resin for forming a fine pattern and a crosslinking component, and when applying the resin composition for forming a fine pattern on the first resist pattern, It does not cause intermixing with the first resist pattern.

  As an alcohol solvent, it is preferable that it is a C1-C8 monohydric alcohol, for example. Specifically, 1-propanol, isopropanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl -1-butanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pen Tanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 1-heptanol 2-heptanol, 2-methyl-2-heptanol, 2-methyl-3-heptanol and the like. Among these, 1-butanol, 2-butanol, and 4-methyl-2-pentanol are preferable. These alcohol solvents can be used alone or in combination of two or more.

  The alcohol solvent may contain water. When water is contained, the content of water is preferably 10% by mass or less, and more preferably 1% by mass or less, based on the total solvent contained in the resin composition for forming a fine pattern. There exists a possibility that the solubility of resin for fine pattern formation may fall that the said content rate is more than 10 mass%. In addition, it is preferable that it is an anhydrous alcohol solvent which does not contain water.

  The resin composition for forming a fine pattern may further contain another solvent for the purpose of adjusting applicability when applied onto the first resist pattern. It is preferable that the other solvent does not erode the first resist pattern and has an action of uniformly applying the resin composition for forming a fine pattern.

  Examples of other solvents include cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol Alkyl ethers of polyhydric alcohols such as diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether Acetate, alkyl ether acetates of polyhydric alcohols such as propylene glycol monomethyl ether acetate;

  Aromatic hydrocarbons such as toluene and xylene; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol; ethyl acetate, butyl acetate, 2-hydroxy Ethyl propionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate And esters such as ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl acetate, butyl acetate, and the like. Among these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, esters, and water are preferable.

  The content of other solvents is preferably 30% by mass or less, and more preferably 20% by mass or less, based on the total solvent contained in the resin composition for forming a fine pattern. If the content is more than 30% by mass, the first resist pattern may be eroded, causing problems such as intermixing with the resin composition for forming a fine pattern, and possibly filling the pattern. is there. In addition, when using water as another solvent, it is preferable that the content rate is 10 mass% or less with respect to all the solvents contained in the resin composition for fine pattern formation.

  The total amount of the fine pattern forming resin and the crosslinking component is preferably 0.1 to 30% by mass, and 1 to 20% by mass with respect to the total amount of the fine pattern forming resin composition including the alcohol solvent. More preferably it is. If the total amount is less than 0.1% by mass, the coating film becomes too thin, and there is a risk of film breakage in the pattern-etched portion. On the other hand, if it exceeds 30% by mass, the viscosity becomes too high and it may not be possible to embed in a fine space.

  The resin composition for forming a fine pattern can be blended with coating properties, antifoaming properties, surfactants, and the like.

  The surfactant is blended for the purpose of improving leveling properties. Examples of the surfactant include BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (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 (Above, manufactured by Asahi Glass Co., Ltd.), SH-28PA, -190, -193, SZ-6032, SF-8428 (above, manufactured by Toray Dow Corning Silicone), etc. Agents can be used. It is preferable that the compounding quantity of surfactant is 5 mass parts or less with respect to 100 mass parts of resin for fine pattern formation.

  A conventionally well-known method can be employ | adopted for the method of apply | coating the resin composition for fine pattern formation. For example, application means such as spin coating, cast coating and roll coating can be used.

  The baking conditions are appropriately selected depending on the composition of the first resist pattern, but the heating temperature is preferably 50 to 250 ° C, more preferably 80 to 150 ° C. The heating time is preferably 20 to 180 seconds, and more preferably 30 to 90 seconds. The pattern formation method of this embodiment can adjust the film thickness of a 1st coating layer by selecting the baking heating conditions suitably.

  The cleaning can be performed by a conventionally known cleaning method. For example, the method of removing the apply | coated resin composition for fine pattern formation using a washing | cleaning liquid can be mentioned. Examples of the cleaning liquid include water, a developer, and an alcohol solvent.

  As described above, for example, as shown in FIG. 2, the first etching mask layer 15 including the first resist pattern 12 and the first covering layer 13 covering the first resist pattern 12. Can be formed on the substrate 11. FIG. 2 is a cross-sectional view of the substrate and the first etching mask layer when the first etching mask layer is formed on the substrate.

[1-3] (3) Step:
The step (3) of the pattern forming method of the present embodiment is a step of etching the substrate using the first etching mask layer as a mask.

As the etching method, two kinds of methods, dry etching and wet etching, can be used, but it is preferable to use dry etching. Examples of reactive gas species used for dry etching include CF ₄ , Ar, O ₂ , and N ₂ . The temperature during etching is preferably 5 to 70 ° C., and the time is preferably 1 to 120 seconds. When wet etching is performed, it is preferable to use hydrofluoric acid.

  FIG. 3 shows an example in which the substrate 11 is etched using the first etching mask layer 15 as a mask.

[1-4] (4) Step:
In the step (4) of the pattern forming method of the present embodiment, after the etching process, the first etching mask layer is removed to obtain a primary processing substrate, and a second positive type feeling is formed on the obtained primary processing substrate. A second resist film was formed using the radiation resin composition, and after the second resist film was selectively exposed, it was developed to form at least a part of the remaining pattern. This is a step of obtaining a second resist pattern.

  The removal of the first etching mask layer can be performed, for example, by ashing. FIG. 4 is an example showing a primary processing substrate 17 having two space portions 19 formed by removing the first etching mask layer after the etching process. FIG. 4 is a cross-sectional view showing the primary processing substrate obtained by removing the first etching mask layer after the etching process. FIG. 5 is a plan view of the primary processing substrate 17 of FIG. 4 as viewed from the side on which the etching process has been performed.

  As the second positive radiation sensitive resin composition, the same one as the first positive radiation sensitive resin composition already described above can be suitably used.

  As a method for forming the second resist film, a conventionally known method can be employed in the same manner as the method for forming the first resist film.

  The development can be performed by a conventionally known method in the same manner as the development in the step (1).

  In this step, selective exposure is performed so that at least a part of the remaining portion of the predetermined pattern is formed. That is, in this step, selective exposure is performed so that a part of the remaining part of the predetermined pattern is formed, and then a part of the remaining part of the predetermined pattern is further selected. Exposure. As described above, the pattern forming method of the present embodiment forms a predetermined pattern by including a step of selectively exposing and developing a plurality of times.

[1-5] Step (5):
The step (5) of the pattern forming method of the present embodiment includes the steps of applying a fine pattern forming resin composition to the second resist pattern, baking, and washing to form the second resist pattern and the second resist pattern. And forming a second etching mask layer on the primary processing substrate.

  This step is a step of forming a second etching mask layer on the primary processing substrate by baking and washing using the fine pattern forming resin composition in the same manner as the above-described step (2). In addition, although the heating conditions of baking are suitably selected by the compounding composition of a 2nd resist pattern, it is preferable that heating temperature is 50-250 degreeC, and it is still more preferable that it is 80-150 degreeC. The heating time is preferably 20 to 180 seconds, and more preferably 30 to 90 seconds. Moreover, the washing | cleaning method can mention the method similar to (2) processes.

  For example, FIG. 6 shows a second etching mask layer comprising a sheet-like second resist pattern 22 and a second covering layer 21 covering the second resist pattern 22 on the primary processing substrate 17. 23 is formed. FIG. 6 is a cross-sectional view of the primary processing substrate and the second etching mask layer when the second etching mask layer is formed on the primary processing substrate.

[1-6] (6) Step:
The step (6) of the pattern forming method of the present embodiment is a step of etching the primary processing substrate using the second etching mask layer as a mask.

  As the etching method, a method similar to the etching process in the above-described step (3) can be suitably employed.

  The pattern formation method of this embodiment obtains a predetermined pattern by repeating the steps (4) to (6) one or more times in order. As described above, by repeating the steps (4) to (6) one or more times in order, a finer pattern can be easily and efficiently formed. Here, “repeating the steps (4) to (6) one or more times in order” means that the steps (4) to (6) are performed at least once in order, and the pattern forming method of the present embodiment includes: For example, the steps (1) to (6) are performed only once in the order of the step (1), the step (2), the step (3), the step (4), the step (5), and the step (6). The steps (1) to (6) may be performed in the order of step (1), step (2), step (3), step (4), step (5), step (6). Thereafter, the steps (4) to (6) may be performed once in the order of the step (4), the step (5), and the step (6). Further, the steps (4) to (6) to be performed can be performed not only once but a plurality of times in order to form a predetermined pattern.

  The number of times of repeating the steps (4) to (6) can be appropriately selected depending on a predetermined pattern or the like, but is preferably 1 to 10 times, more preferably 1 to 7 times, It is particularly preferable that the number is 3 times.

  After the primary processing substrate is etched by this step, the second processing mask layer is removed, whereby a secondary processing substrate on which a predetermined pattern is formed can be obtained. The removal of the second etching mask layer can be performed by the same method as in the step (4). FIG. 7 shows a line-and-space pattern (resist pattern) having five space portions 19 and four line portions 27 by removing the second etching mask layer 23 after the etching process of step (6). This is an example of obtaining the formed secondary processing substrate 25 (substrate). FIG. 7 is a cross-sectional view showing a secondary processing substrate obtained by removing the second etching mask layer after the etching process.

[1-7] Other steps:
In the pattern forming method of this embodiment, other steps may be performed in addition to the steps (1) to (6) described above.

  Other steps are, for example, after the step (1), before the step (2), a step of forming a protective film on the first resist pattern, after the step (4), (5 ) Before the step, a step of forming a protective film on the second resist pattern can be exemplified.

  By forming such a protective film, there is an advantage that it is possible to prevent the influence of basic impurities and the like contained in the environmental atmosphere during exposure. As a protective film, what is disclosed by Unexamined-Japanese-Patent No. 5-188598 etc. can be mentioned, for example.

[2] Resin composition for forming a fine pattern:
One embodiment of the resin composition for forming a fine pattern of the present invention is used in the pattern forming method of the present invention. The resin composition for forming a fine pattern according to this embodiment forms a coating layer insoluble in a developer while being cured by reacting with the first resist pattern by baking. The film thickness of this coating layer can be appropriately set according to the baking conditions.

  The fine pattern forming resin composition of the present embodiment is not particularly limited as long as it is used in the pattern forming method of the present invention, but includes a resin, a crosslinking component that reacts with the resin, and an alcohol solvent. It is preferable. Such a resin composition for forming a fine pattern is suitable as a material for easily and efficiently forming a finer pattern.

[2-1] Resin:
As the resin contained in the resin composition for forming a fine pattern of the present embodiment, the same resin as the resin described in the pattern forming method of the present invention (resin for forming a fine pattern) can be suitably used.

[2-2] Crosslinking component:
As the crosslinking component contained in the resin composition for forming a fine pattern of the present embodiment, the same crosslinking component as described in the pattern forming method of the present invention can be suitably used.

[2-3] Alcohol solvent:
As the alcohol solvent contained in the resin composition for forming a fine pattern of the present embodiment, the same alcohol solvent as described in the pattern forming method of the present invention can be suitably used.

[2-4] Other components:
The resin composition for forming a fine pattern of the present embodiment can further contain other components in addition to the resin, the crosslinking component, and the alcohol solvent. Examples of other components include other solvents already described above, coating properties, antifoaming properties, surfactants, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

(Mw and Mn)
Each polymer obtained in each synthesis example was analyzed using a “GPC column (two G2000HXL, one G3000HXL, one G4000HXL)” manufactured by Tosoh Corporation, a flow rate of 1.0 ml / min, an elution solvent tetrahydrofuran, and a column temperature of 40 ° C. Under the conditions, Mw and Mn were measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard.

(Production of evaluation substrate)
First, 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 with an underlayer antireflection film ARC29A (made by Brewer Science) by CLEAN TRACK ACT8 (made by Tokyo Electron) Then, patterning of a positive radiation sensitive resin composition (“JSR ArF AR1682J” manufactured by JSR) is performed. AR1682J forms a coating film with a film thickness of 150 nm by spin coating, PB (115 ° C., 90 seconds) and cooling (23 ° C., 30 seconds) with the CLEAN TRACK ACT 8, and ArF projection exposure apparatus S306C (manufactured by Nikon Corporation) Then, exposure is performed under the optical conditions of NA: 0.78, Sigma: 0.85, 2/3 Ann, PEB (120 ° C., 90 seconds), cooling (23 ° C., 30 seconds) with the CLEAN TRACK ACT 8 hot plate. ) Then, paddle development (30 seconds) using 2.38 mass% TMAH aqueous solution as a developing solution at the LD nozzle of the developing cup, rinsing with ultra pure water, and then spin drying at 4000 rpm for 15 seconds, 50 nm space / 180 nm A substrate for evaluation of a pitch resist pattern was obtained. 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.

  Next, on the resist pattern of the obtained evaluation substrate A, a fine pattern-forming resin composition was spin-coated using a trade name “CLEAN TRACK ACT12” and applied to a film thickness of 150 nm, In order to react the resist pattern and the resin composition for forming a fine pattern, baking was performed under the shrinkage evaluation baking conditions (140 ° C., 90 seconds) shown in Table 1. After using the product name “CLEAN TRACK ACT12” and cooling with a cooling plate at 23 ° C. for 30 seconds, using a LD nozzle of the developing cup, paddle development (60 seconds) with a 2.38 mass% TMAH aqueous solution as a developer, Rinse with ultrapure water. The substrate B for evaluation on which the fine resist pattern was formed was produced by spin-drying by shaking off at 2000 rpm for 15 seconds.

  For the produced evaluation substrate B, the space width of the pattern corresponding to 50 nm space / 180 nm pitch is measured (indicated as “evaluation of shrinkage” in Table 2), and the pattern is observed and evaluated according to the following evaluation criteria. (In Table 2, indicated as “evaluation (determination) of insoluble matter)”. When the space width dimension is 40 nm or less and there is no insoluble matter at the bottom of the space portion, “◯” is indicated, and when the space width dimension is 40 nm or more or insoluble matters are observed, “X” is indicated. In Table 2, “Dimension before shrinkage (nm)” in “Evaluation of shrinkage” indicates the space width (nm) before baking, and “Dimension after shrinking (nm)” is the space width after baking (nm). ).

(Synthesis Example 1)
As starting materials, 17.21 g of p-hydroxymethacrylanilide (compound represented by the following formula (m-1)), p-tert-butoxystyrene (compound represented by the following formula (m-2)) 8.56 g, 2-(( (Trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate (compound represented by the following formula (m-3)) 4.23 g and azobisisobutyronitrile 2.13 g were dissolved in 90 g of isopropanol (IPA), The polymerization reaction was performed for 6 hours under reflux conditions (82 ° C.). After cooling the reaction vessel with running water, it was poured into 900 g of hexane while stirring, and after reprecipitation, suction filtration was performed. This re-precipitation operation (IPA charging to suction filtration operation) was repeated four times, and then vacuum-dried at a temperature of 50 ° C. As a result, a repeating unit derived from p-hydroxyphenylmethacrylanilide / a repeating unit derived from t-butoxystyrene / 2 a repeating unit derived from 2-(((trifluoromethyl) sulfonyl) amino) ethyl-1-methacrylate = 70/20 / The copolymer 26g (yield 87 mass%) which consists of 10 (molar ratio) was obtained. This copolymer is referred to as “resin (P-1)”.

  Resin (P-1) was Mw 5,800 and Mw / Mn 1.6.

(Synthesis Example 2)
Using the same starting materials as in Synthesis Example 1, as in Synthesis Example 1, repeating unit derived from p-hydroxymethacrylanilide / repeating unit derived from pt-butoxystyrene / 2-(((trifluoromethyl) sulfonyl) A copolymer comprising repeating units derived from amino) ethyl-1-methacrylate = 60/35/5 (molar ratio) was obtained. This resin (P-2) was Mw 5,200 and Mw / Mn 1.5.

(Synthesis Example 3)
Using the same starting materials as in Synthesis Example 1, as in Synthesis Example 1, repeating unit derived from p-hydroxymethacrylanilide / repeating unit derived from pt-butoxystyrene / 2-(((trifluoromethyl) sulfonyl) A copolymer comprising repeating units derived from amino) ethyl-1-methacrylate = 60/30/10 (molar ratio) was obtained. This resin (P-3) was Mw 5,200 and Mw / Mn 1.5.

(Synthesis Example 4)
84.14 g of p-hydroxymethacrylanilide (compound represented by the following formula (m-1)), 35.86 g of pt-butoxystyrene (compound represented by the following formula (m-2)), azobisisobutyronitrile 8 .91 g and 2,81-diphenyl-4-methyl-1-pentene (4.81 g) were dissolved in 360 g of methanol, and a polymerization reaction was carried out for 8 hours under reflux conditions (63 ° C.). The polymerization solution was purified by reprecipitation with a solution of methanol / water and a solution of isopropyl alcohol / heptane, and a repeating unit derived from p-hydroxymethacrylanilide having Mw 8,500 and Mw / Mn 2.08 / pt-butoxystyrene. A copolymer composed of the derived repeating unit = 70/30 (molar ratio) was obtained. This copolymer is referred to as “resin (P-4)”.

Example 1
10 g of resin (P-1), 4.2 g of crosslinking component (C-1), and 270 g of alcohol solvent (S-1) are mixed, stirred for 3 hours, and then filtered using a filter having a pore size of 0.03 μm. Thus, a fine pattern forming resin composition was obtained.

  In this example, the dimension before shrinkage was 50 nm, the dimension after shrinkage was 37 nm, and the evaluation of insoluble matter was “◯”.

In addition, the crosslinking component and alcohol solvent which were used for each Example and the comparative example are shown below.
[Crosslinking component]
C-1: “Nicarac MX-750” (trade name) manufactured by Nippon Carbide
C-2: Dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether [alcohol solvent]
S-1: 1-butanol S-2: 4-methyl-2-pentanol

(Examples 2 to 5, Comparative Example 1)
A resin composition for forming a fine pattern was obtained in the same manner as in Example 1 except that the formulation shown in Table 1 was used. The above evaluation was performed on the obtained resin composition for forming a fine pattern. The evaluation results are shown in Table 2.

  As is clear from Table 2, it is confirmed that the pattern formation methods of Examples 1 to 5 can easily and efficiently form a finer pattern than the pattern formation method of Comparative Example 1. did it.

  The pattern forming method of the present invention can be used as a method for suitably forming a fine pattern in a lithography process in the field of microfabrication represented by the manufacture of an integrated circuit element. Specifically, according to the pattern forming method of the present invention, the pattern gap of the pattern can be effectively miniaturized, and a pattern exceeding the wavelength limit can be formed favorably and economically. For this reason, the pattern forming method of the present invention can be very suitably employed in the field of microfabrication represented by the manufacture of integrated circuit elements that are expected to become increasingly finer in the future.

It is sectional drawing of a board | substrate and a 1st resist pattern when the 1st resist pattern is formed on a board | substrate in the (1) process of the pattern formation method of this invention. It is sectional drawing of a board | substrate and a 1st etching mask layer when the 1st etching mask layer is formed on a board | substrate. It is sectional drawing which shows the state which etched the board | substrate using the 1st mask layer for an etching as a mask. It is sectional drawing which shows the primary processing board | substrate obtained by removing the 1st etching mask layer after an etching process. It is the top view which looked at the primary processing board | substrate of FIG. 4 from the surface side which performed the etching process. It is sectional drawing of a primary processing board | substrate and a 2nd etching mask layer when a 2nd etching mask layer is formed on a primary processing board | substrate. It is sectional drawing which shows the secondary processing board | substrate obtained by removing the 2nd etching mask layer after an etching process.

Explanation of symbols

11: substrate, 12: first resist pattern, 13: first coating layer, 15: first etching mask layer, 17: primary processing substrate, 19: first space portion, 21: second coating Layer, 22: second resist pattern, 23: second etching mask layer, 25: secondary processing substrate, 26: second space portion, 27: line portion.

Claims (5)

A pattern forming method for forming a predetermined pattern on a substrate,
(1) A first resist film is formed on the substrate using the first positive-type radiation-sensitive resin composition, and the first resist film thus formed is selectively exposed and then developed. Obtaining a first resist pattern in which a pattern corresponding to a part of the predetermined pattern is formed;
(2) The fine pattern forming resin composition is applied to the first resist pattern, baked, and washed, and the first resist pattern and the first resist pattern are formed by the fine pattern forming resin composition. Forming a first etching mask layer on the substrate, comprising a coated first covering layer;
(3) using the first etching mask layer as a mask and etching the substrate;
(4) After the etching treatment, the first etching mask layer is removed to obtain a primary treatment substrate, and a second positive radiation sensitive resin composition is used on the obtained primary treatment substrate. A second resist pattern in which a second resist film is formed, the second resist film is selectively exposed and then developed to form a pattern corresponding to at least a part of the remaining portion of the predetermined pattern Obtaining
(5) The resin composition for forming a fine pattern is applied to the second resist pattern, baked, and then washed to form the resin composition for forming a fine pattern with the second resist pattern and the second resist pattern. Forming a second etching mask layer on the primary substrate with a second coating layer coated with
(6) etching the primary processing substrate using the second etching mask layer as a mask;
A pattern forming method for obtaining a predetermined pattern by repeating the steps (4) to (6) one or more times in order.   The pattern forming method according to claim 1, wherein the first resist pattern and the resist pattern formed on the second resist pattern are line-and-space patterns each having a line portion and a space portion.   The pattern forming method according to claim 1, wherein the predetermined pattern formed on the substrate has a hole pattern.   The resin composition for fine pattern formation used by the pattern formation method as described in any one of Claims 1-3.   The resin composition for forming a fine pattern according to claim 4, comprising a resin, a crosslinking component that reacts with the resin, and an alcohol solvent.

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