Composition for forming resist underlayer film

Abstract

This composition for forming a resist underlayer film contains a solvent and a resin (A) having a ring structure and a polymerizable multiple bond group. The ring structure is at least one selected from the group consisting of aromatic rings having 6-26 carbon atoms and non-aromatic rings having 6-10 carbon atoms. The polymerizable multiple bond group has at least one selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond.

Description

Composition for forming resist underlayer film

[0001] The present invention relates to a composition for forming a resist underlayer film, a resist underlayer film, a laminate, a method for producing a semiconductor element, and a method for forming a pattern.

[0002] In the manufacture of semiconductor devices, microfabrication by lithography using a resist composition has traditionally been performed. This microfabrication process involves forming a thin film of a photoresist composition on a semiconductor substrate, such as a silicon wafer, irradiating the substrate with actinic rays such as ultraviolet light through a mask pattern bearing a device pattern, developing the thin film, and etching the substrate using the resulting photoresist pattern as a protective film, thereby forming fine irregularities on the substrate surface corresponding to the photoresist pattern. In recent years, the integration density of semiconductor devices has increased, and in addition to the conventionally used i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), the practical use of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for cutting-edge microfabrication. As a result, poor resist pattern formation due to influences from the semiconductor substrate, etc., has become a major problem. To address this issue, methods of providing a resist underlayer film between the resist and the semiconductor substrate have been widely investigated.

[0003] Patent Document 1 discloses a composition for forming an underlayer film for lithography, which contains a naphthalene ring having a halogen atom. Patent Document 2 discloses a halogenated antireflective film. Patent Document 3 discloses a composition for forming a resist underlayer film.

[0004] International Publication No. 2006 / 003850 Special Publication No. 2005-526270 International Publication No. 2020 / 111068

[0005] Properties required for a resist underlayer film include, for example, the ability to form a resist pattern with high sensitivity, the ability to form a resist pattern with small roughness (LWR (Line Width Roughness)), etc. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition for forming a resist underlayer film that can form a resist pattern with good sensitivity without reducing roughness, as well as methods for producing a resist underlayer film, a laminate, and a semiconductor element, and a pattern formation method that use the composition for forming a resist underlayer film.

[0006] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist.

[0007] That is, the present invention encompasses the following aspects. [1] A composition for forming a resist underlayer film, comprising: a resin (A) having a ring structure and a polymerizable multiple bond group; and a solvent, wherein the ring structure is at least one selected from the group consisting of an aromatic ring having 6 to 26 carbon atoms and a non-aromatic ring having 6 to 10 carbon atoms; and the polymerizable multiple bond group has at least one selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond. [2] The composition for forming a resist underlayer film according to [1], wherein in the resin (A), the polymerizable multiple bond group is bonded to the ring structure by reaction between an epoxy group and a nucleophilic functional group. [3] The composition for forming a resist underlayer film according to [2], wherein the nucleophilic functional group is at least one selected from the group consisting of a carboxy group, a hydroxy group, an amino group, and a thiol group. [4] The composition for forming a resist underlayer film according to any one of [1] to [3], wherein the resin (A) includes, as the partial structure having the polymerizable multiple bond group, a partial structure represented by the following formula (1), and as the partial structure having the ring structure and the polymerizable multiple bond group, at least one of a partial structure represented by the following formula (2) or a partial structure represented by the following formula (3): (In formula (1), L １ is a single bond, —O—CH ２ -, -CH２ —O—, —CH ２ -O-CH ２ -, -CH ２ -O-CO- or -CO-O-CH ２ represents -, L ２ represents a monovalent polymerizable multiple bond group, * １ represents a bond bonded to the ring structure. (In formula (2) and formula (3), L ２ represents a monovalent polymerizable multiple bond group, * ２ represents a bond.) [5] The L ２ is an alkenyl group having 3 to 5 carbon atoms or a hydrocarbon group having 4 to 5 carbon atoms and two carbon-carbon double bonds. [6] The composition for forming a resist underlayer film according to any one of [1] to [5], further comprising a crosslinking agent. [7] The composition for forming a resist underlayer film according to any one of [1] to [6], further comprising an acid generator. [8] A resist underlayer film that is a cured product of the composition for forming a resist underlayer film according to any one of [1] to [7]. [9] A laminate comprising: a semiconductor substrate; and the resist underlayer film according to [8].

[10] A method for manufacturing a semiconductor device, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to [7]; and forming a resist film on the resist underlayer film.

[11] A pattern forming method comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to [7]; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

[0008] According to the present invention, it is possible to provide a composition for forming a resist underlayer film that can form a resist pattern with good sensitivity without reducing roughness, as well as methods for producing a resist underlayer film, a laminate, and a semiconductor element, and a pattern forming method, all of which use the composition for forming a resist underlayer film.

[0009] (Composition for forming a resist underlayer film) The composition for forming a resist underlayer film of the present invention contains a resin (A) and a solvent.

[0010] <Resin (A)> Resin (A) has a ring structure and a polymerizable multiple bond. The ring structure is one or more types selected from the group consisting of aromatic rings having 6 to 26 carbon atoms and non-aromatic rings having 6 to 10 carbon atoms. The polymerizable multiple bond is one or more types selected from the group consisting of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-nitrogen double bonds, and carbon-nitrogen triple bonds.

[0011] The resin (A) is an organic compound. The resin (A) may be a polymer.

[0012] The resin (A) has, for example, a (meth)acryloyl group, a vinylaryl group (for example, a styryl group), a vinyloxy group, an allyl group, or the like, as the group having a polymerizable multiple bond in a side chain.

[0013] Resin (A) is, for example, resin (A-1) having a group having a polymerizable multiple bond in the side chain of a novolac resin. Resin (A) is, for example, resin (A-2) having a group having a polymerizable multiple bond in the side chain of a ring-opening polymer of an alicyclic epoxy compound. Examples of the group having a polymerizable multiple bond include a (meth)acryloyl group, a vinylaryl group (e.g., a styryl group), a vinyloxy group, and an allyl group.

[0014] For example, in resin (A), the polymerizable multiple bond is bonded to the ring structure of resin (A) by reaction between an epoxy group and a nucleophilic functional group. Examples of the nucleophilic functional group include one or more selected from the group consisting of a carboxy group, a hydroxy group, an amino group, and a thiol group. The hydroxy group may or may not be a phenolic hydroxy group. When an epoxy group reacts with a carboxy group, the reaction proceeds as follows, forming the following structure (S1): (In the formula, * represents a bond.)

[0015] The ring structure of the resin (A) is, for example, one or more selected from the group consisting of aromatic rings having 6 to 26 carbon atoms and non-aromatic rings having 6 to 10 carbon atoms. The aromatic ring may be a monocyclic ring, a linked ring, or a fused ring. The aromatic ring has 6 to 26 carbon atoms, preferably 6 to 18, and more preferably 6 to 12 carbon atoms. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, and rings formed by linking or condensing these rings together, with a benzene ring and a naphthalene ring being preferred. Examples of the non-aromatic ring include a non-aromatic hydrocarbon ring, such as a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononane ring, a cyclodecane ring, or a ring derived from norbornene, with a cyclohexane ring being preferred.

[0016] The resin (A) preferably has a partial structure represented by the following formula (1). (In formula (1), L １ is a single bond, —O—CH ２ -, -CH ２ —O—, —CH ２ -O-CH ２ -, -CH ２ -O-CO- or -CO-O-CH ２ represents -, L ２ represents a monovalent polymerizable multiple bond group, * １ represents a bond bonded to the ring structure.

[0017] The resin (A) may have a partial structure represented by the following formula (2) or (3). (In formula (2) and formula (3), L ２ represents a monovalent polymerizable multiple bond group, * ２ represents a bond.)

[0018] L ２ is a monovalent group having a polymerizable multiple bond. The monovalent group may be the polymerizable multiple bond itself. The number of carbon atoms in the monovalent group is not particularly limited, but may be, for example, 1 to 20 or 1 to 10. ２As the alkyl group, for example, an alkenyl group having 3 to 5 carbon atoms and a hydrocarbon group having 4 to 5 carbon atoms and two carbon-carbon double bonds are preferred.

[0019] L ２ Examples of the group include the following monovalent groups (L2-1) to (L2-32). (In the formula, * represents a bond.)

[0020] An example of the resin (A) can be obtained, for example, by reacting an epoxy group-containing compound (E) with a compound (C1) having a polymerizable multiple bond and a carboxy group, as shown below. Examples of the epoxy group-containing compound (E) include benzene substituted with a group having an epoxy group, alicyclic hydrocarbons substituted with a group having an epoxy group, and derivatives thereof. Compound (E1) of the following formula is an example of a derivative of benzene substituted with a group having an epoxy group. Compound (E2) of the following formula is an example of a derivative of alicyclic hydrocarbons substituted with a group having an epoxy group.

[0021] (In the formula, L ２ is L in formula (1) ２ is synonymous with

[0022] (In the formula, L ２ is L in formula (1) ２ is synonymous with

[0023] The reaction can be carried out in the presence of a catalyst such as tetrabutylphosphonium bromide.

[0024] Examples of the epoxy group-containing compound (E) include compounds having the following structural units or structures: (In the formula, a, b, c, and d each independently represent an integer of 0 to 30.)

[0025] Examples of the compound (C1) having a polymerizable multiple bond and a carboxy group include acrylic acid, methacrylic acid, 4-vinylbenzoic acid, sorbic acid, tetrolic acid, tiglic acid, 1-cyclohexene-1-carboxylic acid, 2-benzylacrylic acid, trans-cinnamic acid, trans-4-methoxycinnamic acid, α-phenylcinnamic acid, monomethyl fumarate, α-cyanocinnamic acid, 4-nitrocinnamic acid, and 3-nitrocinnamic acid.

[0026] Resin (A) is not, for example, a polysiloxane. Resin (A) is not, for example, a hydrolysis condensate of a hydrolyzable silane. Resin (A) is not, for example, a reaction product of a tetracarboxylic dianhydride and a diepoxy compound having two epoxy groups. Resin (A) is not, for example, a reaction product of a tetracarboxylic dianhydride, a diepoxy compound having two epoxy groups, and a monohydroxy compound having one hydroxy group. Resin (A) does not, for example, have an isocyanuric acid skeleton having an alkenyl group. Examples of alkenyl groups include alkenyl groups having 3 to 6 carbon atoms. Examples of alkenyl groups having 3 to 6 carbon atoms include allyl groups.

[0027] The content of the resin (A) in the composition for forming a resist underlayer film is, for example, preferably 50 to 100 mass %, and more preferably 70 to 95 mass %, based on the mass of the film-forming components. Here, the film-forming components refer to the components remaining after excluding the solvent component from the composition for forming a resist underlayer film.

[0028] The molecular weight of the resin (A) is not particularly limited. The lower limit of the weight average molecular weight of the resin (A) is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight average molecular weight of the resin (A) is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000.

[0029] <Solvent> The solvent used in the composition for forming a resist underlayer film is not particularly limited as long as it can uniformly dissolve the components contained therein, such as the resin (A), but organic solvents generally used in chemical solutions for semiconductor lithography processes are preferred. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cyclohexane, cyclohexane-1, cyclohexane-2, cyclohexane-3, cyclohexane-4, cyclohexane-5, cyclohexane-6, cyclohexane-7, cyclohexane-8, cyclohexane-9, cyclohexane-11, cyclohexane-12, cyclohexane-13, cyclohexane-14, cyclohexane-15, cyclohexane-16, cyclohexane-17, cyclohexane-18, cyclohexane-19, cyclohexane-20, cyclohexane-21, cyclohexane-22, cyclohexane-23, cyclohexane-24, cyclohexane-25, cyclohexane-26, cyclohexane-27, cyclohexane-28, cyclohexane-29, cyclohexane-30, cyclohexane-31, cyclohexane-32, cyclohexane-33, cyclohexane-34, cyclohexane-35, cyclohexane-36, cyclohexane-37, cyclohexane-38, cyclohexane-49, cyclohexane-49, cyclohexane-49, cyclohexane-51, cyclohexane-52, cyclohexane-53, cyclohexane-19, cyclohexane-19, cyclohexane-29, cyclohexane-38, cyclohexane- Examples of suitable solvents include heptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents may be used alone or in combination of two or more.

[0030] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, methyl 2-hydroxyisobutyrate and cyclohexanone are preferred, with propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate being particularly preferred.

[0031] <Acid Generator> The acid generator contained as an optional component in the composition for forming a resist underlayer film may be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator. Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate (pyridinium p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium p-hydroxybenzenesulfonic acid (pyridinium p-phenolsulfonate salt), pyridinium trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, and hydroxybenzoic acid.

[0032] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0033] Examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate; and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0034] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0035] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0036] The acid generators may be used singly or in combination of two or more.

[0037] When an acid generator is used, the content of the acid generator relative to the crosslinking agent described below is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass.

[0038] <Crosslinking Agent> The crosslinking agent is not particularly limited. Examples of the crosslinking agent include compounds having two or more of the following structures: (In the structure, R １０１ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms. * represents a bond.) The bond is bonded to, for example, a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0039] R １０１ is preferably a hydrogen atom, a methyl group, an ethyl group or a group represented by the following structure. (In the structure, R １０２ represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond.

[0040] As the crosslinking agent, a melamine compound, a guanamine compound, a glycoluril compound, a urea compound, or a compound having a phenolic hydroxy group is preferred. These may be used alone or in combination of two or more.

[0041] The melamine compound is not particularly limited as long as it has a group capable of reacting with a hydroxy group, and examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which one to six methylol groups of hexamethylol melamine are methoxymethylated, or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which one to six methylol groups of hexamethylol melamine are acyloxymethylated, or a mixture thereof.

[0042] The guanamine compound is not particularly limited as long as it has a group capable of reacting with a hydroxy group, and examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof.

[0043] The glycoluril compound is not particularly limited as long as it has a group capable of reacting with a hydroxy group, and examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, a compound in which one to four methylol groups of tetramethylol glycoluril are methoxymethylated or a mixture thereof, and a compound in which one to four methylol groups of tetramethylol glycoluril are acyloxymethylated or a mixture thereof.

[0044] The glycoluril compound may be, for example, a glycoluril derivative represented by the following formula (1E). (In formula (1E), four R １ each independently represents a methyl group or an ethyl group, R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

[0045] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0046] The glycoluril derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0047] (In formula (2E), R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; R ４ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0048] (In formula (3d), R １ represents a methyl group or an ethyl group.)

[0049] Examples of glycoluril derivatives represented by formula (2E) include compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include compounds represented by formulas (3d-1) and (3d-2) below.

[0050] The urea compound is not particularly limited as long as it has a group capable of reacting with a hydroxy group, and examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, a compound in which one to four methylol groups of tetramethylol urea are methoxymethylated, or a mixture thereof, and tetramethoxyethyl urea.

[0051] Examples of the compound having a phenolic hydroxy group include compounds represented by the following formula (111) or (112). (In formula (111) and formula (112), Q ２ represents a single bond or a divalent organic group. ８ , R ９ , R １１ and R １２ R represents a hydrogen atom or a methyl group. ７ and R １０ n represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. ９ is 1≦n ９ an integer ≦3, n １０ is 2≦n １０ n is an integer ≦5 １１ is 0≦n １１ an integer ≦3, n １２ is 0≦n １２ an integer ≦3, 3≦(n ９ +n １０ +n １１ +n １２ ) represents an integer ≦6. １３ is 1≦n １３ an integer ≦3, n １４ is 1≦n １４ n is an integer ≦4 １５ is 0≦n １５ an integer ≦3, n １６ is 0≦n １６ an integer ≦3, 2≦(n １３ +n １４ +n １５ +n １６ ) represents an integer of ≦5. m2 represents an integer of 2 to 10. ２ In the above, the m2-valent organic group includes, for example, an m2-valent organic group having 1 to 4 carbon atoms.

[0052] Examples of the compound represented by formula (111) or formula (112) include the following compounds. The above compound is available as a product of Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. An example of the product is TMOM-BP, a product name of Asahi Organic Chemicals Co., Ltd.

[0053] Among these, glycoluril compounds are preferred, specifically tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, tetramethylol glycoluril compounds in which one to four methylol groups are methoxymethylated or mixtures thereof, and tetramethylol glycoluril compounds in which one to four methylol groups are acyloxymethylated or mixtures thereof, with tetramethoxymethyl glycoluril being preferred.

[0054] The molecular weight of the crosslinking agent is not particularly limited, but is preferably 500 or less.

[0055] The content of the crosslinking agent in the composition for forming a resist underlayer film is not particularly limited, but is, for example, 1% by mass to 50% by mass, and preferably 5% by mass to 40% by mass, relative to the resin (A).

[0056] <Thermal Radical Polymerization Initiator> The polymerizable multiple bonds of the resin (A) are polymerized by heating, even in the absence of a thermal radical polymerization initiator. Therefore, the resist underlayer film-forming composition does not need to contain a thermal radical polymerization initiator. Polymerization of the polymerizable multiple bonds may be initiated by radicals generated by thermal decomposition of additives such as polymers, solvents, and crosslinking agents in the composition, or impurities contained therein. A resist underlayer film-forming composition that does not contain a thermal radical polymerization initiator has superior storage stability compared to a resist underlayer film-forming composition that contains a thermal radical polymerization initiator. Therefore, the content of the thermal radical polymerization initiator in the resist underlayer film-forming composition is preferably low. The content of the thermal radical polymerization initiator in the resist underlayer film-forming composition is preferably 0% to 1% by mass, more preferably 0% to 0.5% by mass, and particularly preferably 0% to 0.1% by mass, relative to the resin (A).

[0057] Examples of the thermal radical polymerization initiator include peroxides, azo compounds, persulfates, etc. Examples of the peroxides include acetyl peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxypivalate, and tert-butylperoxy-2-ethylhexanoate (tert-butyl 2-ethylhexaneperoxoate). Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), (1-phenylethyl)azodiphenylmethane, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(1-cyclohexanecarbonitrile), 2-(carbamoylazo)isobutyronitrile, 2,2'-azobis(2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, and 2,2'-azobis(2-methylpropane). Examples of persulfates include ammonium persulfate, sodium persulfate, and potassium persulfate. The thermal radical polymerization initiator may be a commercially available product.

[0058] <Other Components> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, etc., and further improve coating properties for surface unevenness. Furthermore, any polymer other than the resin (A) may be added. Examples of such polymers include polymers described in International Publication No. 2013 / 018802 and polymers containing hydroxyarene.

[0059] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate; nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as Eftop EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, and R-30 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by AGC Inc.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2.0 mass % or less, and preferably 1.0 mass % or less, based on the total solid content of the composition for forming a resist underlayer film. These surfactants may be added alone or in combination of two or more.

[0060] The solid content of the composition for forming a resist underlayer film of the present invention, that is, the content of components excluding the solvent, is, for example, 0.01% by mass to 10% by mass.

[0061] (Resist Underlayer Film) The resist underlayer film of the present invention is a cured product of the composition for forming a resist underlayer film described above. The resist underlayer film can be produced, for example, by applying the composition for forming a resist underlayer film described above onto a semiconductor substrate and baking the applied composition.

[0062] Examples of semiconductor substrates onto which the resist underlayer film-forming composition can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0063] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin coating (spin-on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium nitride oxide film, a tungsten film, a gallium nitride film, and a gallium arsenide film.

[0064] The resist underlayer film-forming composition of the present invention is applied to such a semiconductor substrate by a suitable application method such as a spinner or coater. The composition is then baked using a heating means such as a hot plate to form a resist underlayer film. The baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0065] The thickness of the resist underlayer film may be, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm) to 0.05 μm (50 nm), 0.002 μm (2 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.05 μm (50 nm), 0.004 μm (4 nm) to 0.05 μm (50 nm), 0.005 μm (5 nm) to 0.05 μm (5 0 nm), 0.003 μm (3 nm) to 0.03 μm (30 nm), 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.003 μm (3 nm) to 0.01 μm (10 nm), 0.005 μm (5 nm) to 0.01 μm (10 nm), 0.003 μm (3 nm) to 0.006 μm (6 nm), or 0.005 μm (5 nm).

[0066] The method for measuring the film thickness of the resist underlayer film in this specification is as follows: Name of measuring device: Ellipso film thickness measuring device RE-3100 (SCREEN Corporation) SWE (single wavelength ellipsometer) mode Arithmetic mean of 8 points (for example, measuring 8 points at 1 cm intervals in the X direction of the wafer)

[0067] (Laminate) The laminate of the present invention includes a semiconductor substrate and the resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrates described above. The resist underlayer film is disposed on the semiconductor substrate, for example.

[0068] (Method for manufacturing a semiconductor element, method for forming a pattern) The method for manufacturing a semiconductor element of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, and forming a resist film on the resist underlayer film.

[0069] The pattern forming method of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, forming a resist film on the resist underlayer film, irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0070] Usually, a resist layer is formed on the resist underlayer film. The thickness of the resist layer is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less. The thickness of the resist layer is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more.

[0071] The resist film formed on the resist underlayer film by a known method (e.g., resist coating and baking) is not particularly limited as long as it is responsive to light or electron beam (EB) used for irradiation. Both negative and positive photoresists can be used. In this specification, resists responsive to EB are also referred to as photoresists. Examples of photoresists include positive photoresists composed of a novolak resin and a 1,2-naphthoquinone diazide sulfonic acid ester; chemically amplified photoresists composed of a binder having a group that decomposes in an acid to increase the alkaline dissolution rate and a photoacid generator; chemically amplified photoresists composed of a low-molecular-weight compound that decomposes in an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator; chemically amplified photoresists composed of a binder having a group that decomposes in an acid to increase the alkaline dissolution rate, a low-molecular-weight compound that decomposes in an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator; and resists containing metal elements. Examples of such photoresists include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further examples include fluorine-containing polymer photoresists such as those described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0072] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO201 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0073] Examples of the resist composition include the following compositions.

[0074] An actinic ray-sensitive or radiation-sensitive resin composition comprising: Resin B having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (121):

[0075] In the general formula (121), m represents an integer of 1 to 6. １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ - or -SO ３ - represents. ２ represents an alkylene group which may have a substituent or a single bond. １ represents a cyclic organic group which may have a substituent. ＋ represents a cation.

[0076] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0077] A radiation-sensitive resin composition comprising: a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group; and an acid generator.

[0078] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. １ is a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, multiple R １ are the same or different. ２ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ３ is a monovalent group having 1 to 20 carbon atoms containing the above acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. R ４is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0079] A resist composition comprising: a resin (C) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0080] [In the formula, R ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X １ represents a single bond, —CO—O—*, or —CO—NR ４ -*, * represents a bond to -Ar, R ４ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have one or more groups selected from the group consisting of a hydroxy group and a carboxy group.]

[0081] Examples of the resist film include the following.

[0082] A resist film comprising a base resin comprising a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure:

[0083] (In formula (a1) and formula (a2), R Ａ are each independently a hydrogen atom or a methyl group. １ and R ２ are each independently a tertiary alkyl group having 4 to 6 carbon atoms. ３ are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. １ X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ is a single bond, an ester bond, or an amide bond.

[0084] Examples of resist materials include the following:

[0085] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0086] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １ is a single bond or an ester group. ２ is a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group; and X ２ At least one hydrogen atom contained in X is substituted with a bromine atom. ３ Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. １ ~Rf ４ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. １ and Rf ２ may combine to form a carbonyl group. １ ~R ５ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and in which some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate ester group. １ and R ２may be bonded to form a ring together with the sulfur atom to which they are attached.

[0087] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0088] (In formula (a), R Ａ is a hydrogen atom or a methyl group. １ is a hydrogen atom or an acid labile group. ２ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ X is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. ２ is -O-, -O-CH ２ - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m+u is an integer of 1 to 4.

[0089] A resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the fluorine additive component (F) comprises a fluororesin component (F1) that has a structural unit (f1) that includes a base dissociable group, and a structural unit (f2) that includes a group represented by the following general formula (f2-r-1):

[0090] [In formula (f2-r-1), Rf ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, a hydroxyalkyl group, or a cyano group. n" is an integer of 0 to 2. * is a bond.

[0091] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0092] [In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A ａｒｙｌ represents a divalent aromatic cyclic group which may have a substituent. ０１ is a single bond or a divalent linking group. ２ are each independently an organic group having a fluorine atom.

[0093] The resist composition may be a metal-containing resist. Metal-containing resists are also called metal oxide resists (MOR), and a representative example is a tin oxide-based resist. Examples of metal oxide resist materials include coating compositions containing metal oxo-hydroxo networks having organic ligands via metal-carbon bonds and / or metal carboxylate bonds, as described in JP-A-2019-113855. One example of a metal-containing resist uses a peroxo ligand as a radiation-sensitive stabilizing ligand. Details of peroxo-based metal oxo-hydroxo compounds are described, for example, in the patent document described in paragraph

[0011] of JP-A-2019-532489. Examples of such patent documents include U.S. Pat. No. 9,176,377 B2, U.S. Patent Application Publication No. 2013 / 0224652 A1, U.S. Pat. No. 9,310,684 B2, U.S. Patent Application Publication No. 2016 / 0116839 A1, and U.S. Patent Application Publication No. 15 / 291738.

[0094] A coating comprising a metal oxo-hydroxo network having organic ligands with metal carbon and / or metal carboxylate bonds.

[0095] Inorganic oxo-hydroxo-based compositions.

[0096] a coating solution comprising an organic solvent; a first organometallic composition having the formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (where 0<z≦2 and 0<(z+x)≦4), formula R′ｎ SnX ４－ｎ wherein n=1 or 2, or mixtures thereof, where R and R′ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn, or a combination thereof; and a hydrolyzable metal compound having the formula MX′ ｖ wherein M is a metal selected from groups 2 to 16 of the periodic table of the elements, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable M-X bond or a combination thereof.

[0097] an organic solvent and a solution of the formula RSnO （３／２－ｘ／２） (OH) ｘ and a first organometallic compound of the formula: wherein 0<x<3, wherein the solution contains from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having from 3 to 31 carbon atoms, the alkyl or cycloalkyl group being bonded to the tin at a secondary or tertiary carbon atom.

[0098] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0099] Other examples of metal-containing resists include those described in JP 2011-253185 A, WO 2015 / 026482, WO 2016 / 065120, WO 2017 / 066319, WO 2017 / 156388, WO 2018 / 031896, JP 2020-122959 A, JP 2020-122960 A, WO 2019 / 099981, WO 2019 / 199467, WO 2019 / 195522, WO 2019 / 195522, WO 2020 / 210660, WO 2021 / 011367, and WO 2021 / 016229. The contents of these are incorporated herein in their entirety to the same extent as if set forth in full.

[0100] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and examples include a method in which a coating-type resist material (a composition for forming a metal-containing resist film) that is a metal-containing resist is coated and baked.

[0101] The metal-containing resist film may also be formed by vapor deposition. Examples of methods for forming a metal-containing resist film by vapor deposition include the method described in JP 2017-116923 A. The contents of JP 2017-116923 A are incorporated herein by reference to the same extent as if fully set forth herein. In JP 2017-116923 A, the metal-containing resist film of the present invention is referred to as a metal oxide-containing film.

[0102] Irradiation with light or electron beams is carried out, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-line, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam) can be used. The composition for forming a resist underlayer film of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, more preferably for EUV (extreme ultraviolet) exposure. The irradiation energy of the electron beam and the exposure dose of light are not particularly limited.

[0103] After irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60° C. to 150° C., more preferably 70° C. to 120° C., and particularly preferably 75° C. to 110° C. The baking time is not particularly limited, but is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.

[0104] For example, an alkaline developer or an organic solvent is used for development. The development temperature is, for example, 5°C to 50°C. The development time is, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis may be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like may also be added to these developers. Alternatively, development may be carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the portions of the photoresist where the alkaline dissolution rate is not improved may be developed.

[0105] An organic solvent can be used as a developer for the metal-containing resist, and development is carried out with the developer (solvent) after irradiation with light or electron beams. As a result, for example, when a negative metal-containing resist film is used, the metal-containing resist film in the unexposed areas is removed, and a pattern of the metal-containing resist film is formed. Examples of the developer (organic solvent) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methyl ... -Methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3 -methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate,Examples of the developer include propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate. Furthermore, surfactants and the like can also be added to these developers.

[0106] Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred. If the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed. If the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. Thereafter, the semiconductor substrate is processed by a known method (e.g., dry etching), thereby manufacturing a semiconductor device.

[0107] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

[0108] The weight-average molecular weights of the polymers shown in the synthesis examples below in this specification are the results of measurement by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC device manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions were as follows: GPC column: Shodex KF803L, Shodex KF802, Shodex KF801 (registered trademark) (Showa Denko K.K.); column temperature: 40°C; solvent: dimethylformamide (DMF); flow rate: 1.0 ml / min; standard sample: polystyrene (manufactured by Tosoh Corporation).

[0109] Synthesis Example 1 4.06 g of cresol novolac epoxy resin EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), 1.77 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.24 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 23.67 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 100°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight-average molecular weight of the polymer in the obtained solution was 4900 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1a):

[0110] Synthesis Example 2 4.06 g of cresol novolac epoxy resin EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), 2.51 g of sorbic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.09 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.48 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 15.66 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight-average molecular weight of the polymer in the obtained solution was 5,300 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1b):

[0111] Synthesis Example 3 2.96 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 1.73 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.43 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 15.36 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 85°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4,500 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2a): In the formula, R is bonded from the carbon atom side of cyclohexane.

[0112] Synthesis Example 4 2.96 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 2.25 g of sorbic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.43 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 16.93 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 85°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 5,000 in terms of standard polystyrene. The polymer obtained in this Synthesis Example has a structural unit represented by the following formula (2b): In the formula, R is bonded from the carbon atom side of cyclohexane.

[0113] Synthesis Example 5 5.88 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 5.32 g of 4-vinylbenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.55 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 27.49 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 85°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4900 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2c): In the formula, R is bonded from the carbon atom side of cyclohexane.

[0114] Synthesis Example 6 3.53 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 3.19 g of trans-cinnamic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.05 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.23 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 17.40 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4,600 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2d): In the formula, R is bonded from the carbon atom side of cyclohexane.

[0115] Synthesis Example 7 3.53 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 3.84 g of trans-4-methoxycinnamic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.05 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.23 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 18.91 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4,800 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2e): In the formula, R is bonded from the carbon atom side of cyclohexane.

[0116] Synthesis Example 8 3.53 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 4.83 g of α-phenylcinnamic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.05 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.23 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 21.23 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4700 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2f): In the formula, R is bonded from the carbon atom side of cyclohexane.

[0117] Synthesis Example 9 5.88 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 2.53 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.55 g of 3,5-diiodosalicylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.08 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.55 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to a reaction vessel and dissolved in 34.55 g of propylene glycol monomethyl ether acetate. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4,400 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2g): R in the formula is bonded from the carbon atom side of cyclohexane.

[0118] Synthesis Example 10 5.88 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 2.53 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.26 g of 2,3,5-triiodobenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.08 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.55 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to a reaction vessel and dissolved in 36.70 g of propylene glycol monomethyl ether acetate. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 4,400 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2h): R in the formula is bonded from the carbon atom side of cyclohexane.

[0119] Synthesis Example 11 5.98 g of cresol novolac epoxy resin EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), 4.51 g of 4-vinylbenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.02 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.47 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 25.63 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 85°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 5,300 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1c).

[0120] Synthesis Example 12 5.98 g of cresol novolac epoxy resin EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), 3.69 g of 4-vinylbenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.16 g of 3,5-diiodosalicylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.02 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.47 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to a reaction vessel and dissolved in 28.75 g of propylene glycol monomethyl ether acetate. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 85°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution, calculated in terms of standard polystyrene, was 4900. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1d).

[0121] Synthesis Example 13 5.98 g of cresol novolac epoxy resin EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), 3.69 g of 4-vinylbenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.76 g of 2,3,5-triiodobenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.02 g of 4-hydroxy-TEMPO free radical (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.47 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to a reaction vessel and dissolved in 30.17 g of propylene glycol monomethyl ether acetate. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 85°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution, calculated in terms of standard polystyrene, was 4700. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1e).

[0122] Synthesis Example 14 10.00 g of polyglycidyl methacrylate (manufactured by Maruzen Petrochemical Co., Ltd.), 2.38 g of propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.21 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 21 g of propylene glycol monomethyl ether acetate and 32 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The reaction vessel was purged with nitrogen, and the mixture was reacted at 80°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 10,426 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (3a):

[0123] Synthesis Example 15 100 g of monoallyl diglycidyl isocyanurate (manufactured by Shikoku Chemicals Corporation), 66.4 g of 5,5-diethylbarbituric acid, and 4.1 g of benzyltriethylammonium chloride were dissolved in 682 g of propylene glycol monomethyl ether, and the mixture was allowed to react at 130°C for 24 hours to obtain a solution containing a polymer. GPC analysis of the obtained polymer revealed that the weight average molecular weight, calculated as standard polystyrene, was 6,800. The obtained polymer is considered to be a polymer having the structure of formula (3b) as a repeating unit structure.

[0124] [Example 1] 0.0171 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.171 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 26.43 g of propylene glycol monomethyl ether, and 2.99 g of propylene glycol monomethyl ether acetate were added and dissolved in 0.388 g of the polymer solution (solid content 17.57%) obtained in Synthesis Example 1. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0125] [Example 2] 0.0106 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.106 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 26.72 g of propylene glycol monomethyl ether, and 2.99 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.173 g of the polymer solution (solid content 24.48%) obtained in Synthesis Example 2. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0126] [Example 3] 0.0171 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.171 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 26.47 g of propylene glycol monomethyl ether, and 2.99 g of propylene glycol monomethyl ether acetate were added and dissolved in 0.355 g of the polymer solution (solid content 19.22%) obtained in Synthesis Example 3. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0127] [Example 4] 0.0106 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.106 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 26.65 g of propylene glycol monomethyl ether, and 2.99 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.240 g of the polymer solution (solid content 17.63%) obtained in Synthesis Example 4. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0128] [Example 5] 0.0187 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.874 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 102.55 g of propylene glycol monomethyl ether, and 43.57 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.3551 g of the polymer solution (solid content 21.12%) obtained in Synthesis Example 5. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0129] [Example 6] 0.0577 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.5769 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 44.67 g of propylene glycol monomethyl ether, and 4.88 g of propylene glycol monomethyl ether acetate were added to and dissolved in 1.5720 g of the polymer solution (solid content 14.68%) obtained in Synthesis Example 6. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 µm to obtain a composition for forming a resist underlayer film.

[0130] [Example 7] 0.0577 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.5769 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 44.67 g of propylene glycol monomethyl ether, and 4.88 g of propylene glycol monomethyl ether acetate were added to and dissolved in 1.4946 g of the polymer solution (solid content 15.44%) obtained in Synthesis Example 7. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 µm to obtain a composition for forming a resist underlayer film.

[0131] [Example 8] 0.0588 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.5882 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 103.09 g of propylene glycol monomethyl ether, and 43.64 g of propylene glycol monomethyl ether acetate were added to and dissolved in 1.4987 g of the polymer solution (solid content 15.70%) obtained in Synthesis Example 8. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 µm to obtain a composition for forming a resist underlayer film.

[0132] [Example 9] 0.1003 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 1.0073 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 41.8675 g of propylene glycol monomethyl ether, and 102.2733 g of propylene glycol monomethyl ether acetate were added to and dissolved in 2.711 g of the polymer solution (solid content 14.86%) obtained in Synthesis Example 9. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0133] [Example 10] 0.1029 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 1.0294 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 41.8675 g of propylene glycol monomethyl ether, and 102.2733 g of propylene glycol monomethyl ether acetate were added to and dissolved in 2.7161 g of the polymer solution (solid content 15.16%) obtained in Synthesis Example 10. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film.

[0134] [Comparative Example 1] 0.0106 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.106 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 26.69 g of propylene glycol monomethyl ether, and 2.99 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.354 g of the polymer solution (solid content 19.41%) obtained in Synthesis Example 14. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 µm to obtain a composition for forming a resist underlayer film.

[0135] [Comparative Example 2] 0.0171 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.171 g of a 1% propylene glycol monomethyl ether solution of pyridinium toluenesulfonic acid, 20.41 g of propylene glycol monomethyl ether, and 8.97 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.427 g of the polymer solution (solid content 15.98%) obtained in Synthesis Example 15. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 µm to obtain a composition for forming a resist underlayer film.

[0136] [Elution Test in Photoresist Solvent] Each of the resist underlayer film-forming compositions of Examples 1 to 10 and Comparative Examples 1 and 2 was applied to a silicon wafer, which is a semiconductor substrate, using a spinner. The silicon wafer was placed on a hot plate and baked at 215°C for 1 minute to form a resist underlayer film (film thickness: 5 nm). These resist underlayer films were immersed in propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate (mass ratio = 7 / 3), a solvent used in photoresists, and it was confirmed that they were insoluble in these solvents.

[0137] [Formation of Resist Pattern by EUV Exposure: Negative Organic Solvent Development] Each of the resist underlayer film-forming compositions of Examples 1, 2, 3, 4, and Comparative Examples 1 and 2 was applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 215°C for 60 seconds to obtain a 5 nm-thick resist underlayer film. An EUV resist solution (tin oxide-based resist) was spin-coated thereon and heated at 130°C for 1 minute to form an EUV resist layer. The resist layer was then exposed using an ASML EUV exposure system (NXE3400) under conditions of NA = 0.33, σ = 0.60 / 0.82 (outer / inner), and dipole. During exposure, the EUV resist was exposed through a mask configured so that the line width and the width between lines (space width) of the EUV resist after the following development would be 14 nm, i.e., so that dense lines with a line-and-space (L / S) ratio of 1 / 1 would be formed. After exposure, post-exposure baking (PEB, 180°C for 1 minute) was performed, followed by cooling to room temperature on a cooling plate. The resist was developed for 60 seconds using an organic solvent (propylene glycol monomethyl ether acetate) and rinsed to form a resist pattern. Using a critical dimension SEM (CG4100) manufactured by Hitachi High-Technologies Corporation, the exposure dose at which a line dimension of 14 nm was formed was measured, and this was taken as sensitivity. The minimum pattern size formed without pattern peeling or collapse was taken as MinCD. In forming the resist patterns, the LWR (Line Width Roughness) at a CD size of 14 nm was compared. Furthermore, the Z-factor (Z-factor), expressed by the following formula (I), was calculated as an index for comprehensively evaluating the performance of the resist. The smaller the values ​​of sensitivity, MinCD, LWR, and Z-factor, the better the resist performance. The results are shown in Table 1. Z-factor=(MinCD) ３ × (LWR) ２ × (sensitivity) ... (I)

[0138]

[0139] As shown in Table 1, Examples 1 to 4 according to the present invention were found to be superior in sensitivity and resolution (MinCD, LWR, Z-factor) compared to Comparative Example 1 in which the polymer did not contain a polymerizable multiple bond and Comparative Example 2 in which the polymer did not have a specific ring structure.

Claims

1. A composition for forming a resist underlayer film, comprising: a resin (A) having a ring structure and a polymerizable multiple bond group; and a solvent; wherein the ring structure is one or more selected from the group consisting of an aromatic ring having 6 to 26 carbon atoms and a non-aromatic ring having 6 to 10 carbon atoms; and the polymerizable multiple bond group has one or more selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond.

2. The composition for forming a resist underlayer film according to claim 1, wherein in the resin (A), the polymerizable multiple bond group is bonded to the ring structure by reaction between an epoxy group and a nucleophilic functional group.

3. The composition for forming a resist underlayer film according to claim 2, wherein the nucleophilic functional group is at least one selected from the group consisting of a carboxy group, a hydroxy group, an amino group and a thiol group.

4. The composition for forming a resist underlayer film according to claim 1, wherein the resin (A) contains, as the partial structure having the polymerizable multiple bond group, a partial structure represented by the following formula (1), and as the partial structure having the ring structure and the polymerizable multiple bond group, at least one of a partial structure represented by the following formula (2) or a partial structure represented by the following formula (3): (In formula (1), L １ is a single bond, -O-CH ２ --, --CH ２ -O-, -CH ２ -O-CH ２ --, --CH ２ -O-CO- or -CO-O-CH ２ - represents L ２ represents a monovalent polymerizable multiple bond group, * １ represents a bond bonded to the ring structure. (In formula (2) and formula (3), L ２ represents a monovalent polymerizable multiple bond group, * ２ represents a bond.) 5. Said L ２ The composition for forming a resist underlayer film according to claim 4, wherein is an alkenyl group having 3 to 5 carbon atoms or a hydrocarbon group having 4 to 5 carbon atoms and two carbon-carbon double bonds.

6. The composition for forming a resist underlayer film according to claim 1, further comprising a crosslinking agent.

7. The composition for forming a resist underlayer film according to claim 1, further comprising an acid generator.

8. A resist underlayer film which is a cured product of the composition for forming a resist underlayer film according to any one of claims 1 to 7.

9. A laminate comprising: a semiconductor substrate; and the resist underlayer film according to claim 8.

10. A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 7; and a step of forming a resist film on the resist underlayer film.

11. A pattern forming method comprising the steps of: forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 7; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

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