Composition for forming resist underlayer film

Abstract

Provided is a composition for forming a resist underlayer film, the composition comprising a resin (A), a photobase generator (B), and a solvent (C), wherein the resist underlayer film is formed between a metal-containing resist film and a substrate.

Description

Composition for forming a 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 manufacturing a semiconductor device, and a method for forming a pattern.

[0002] Conventionally, microfabrication using lithography with resist compositions has been performed in the manufacturing of semiconductor devices. This microfabrication method involves forming a thin film of a photoresist composition on a semiconductor substrate such as a silicon wafer, irradiating it with an active light such as ultraviolet light through a mask pattern on which the device pattern is drawn, developing the film, and then 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, with the increasing integration density of semiconductor devices, the active light used has also evolved. 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 application of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for cutting-edge microfabrication. Consequently, poor resist pattern formation due to influence from the semiconductor substrate has become a major problem. Therefore, in order to solve this problem, methods of providing a resist underlayer film between the resist and the semiconductor substrate are being widely investigated.

[0003] For example, Patent Documents 1 and 2 propose a method for manufacturing a semiconductor substrate, which includes a step of forming a metal-containing resist film on a resist underlayer film formed from a resist underlayer film composition.

[0004] International Publication No. 2022 / 202402 Brochure International Publication No. 2022 / 209816 Brochure

[0005] The required properties of a resist underlayer include, for example, that it does not intermix with the resist film formed on the upper layer (i.e., it is insoluble in the resist solvent), and that it can form a resist pattern with high sensitivity. The present invention has been made in view of the above circumstances, and aims to provide a resist underlayer film formation composition that can form a resist pattern with high sensitivity, as well as a method for manufacturing a resist underlayer film, a laminate, a semiconductor device, and a pattern formation method using the resist underlayer film formation composition.

[0006] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, found that they could solve the above problems, and completed the present invention having the following gist.

[0007] In other words, the present invention encompasses the following aspects: [1] A resist underlayer forming composition for forming a resist underlayer film between a metal-containing resist film and a substrate, comprising a resin (A), a photobase generator (B), and a solvent (C). [2] The resist underlayer forming composition according to [1], wherein the resin (A) is at least one selected from the group consisting of poly(meth)acrylic resin, polyester resin, polyether resin, polyvinyl resin, resin having an isocyanuric acid structure, resin having a barbituric acid structure, and resin having a hydantoin structure. [3] The resist underlayer forming composition according to [1] or [2], wherein the photobase generator (B) is an ionic photobase generator. [4] The resist underlayer forming composition according to [1] or [2], wherein the photobase generator (B) is a nonionic photobase generator. [5] The resist underlayer film forming composition according to any one of [1] to [4], wherein the solvent (C) comprises at least one selected from the group consisting of a carboxylic acid having a hydroxyl group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol monoalkyl ether, a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether. [6] The resist underlayer film forming composition according to any one of [1] to [5], further comprising a crosslinking agent (D). [7] The resist underlayer film forming composition according to [6], wherein the crosslinking agent (D) is at least one selected from the group consisting of an aminoplast crosslinking agent and a phenoplast crosslinking agent. [8] The resist underlayer film forming composition according to any one of [1] to [7], further comprising a curing catalyst (E). [9] The resist underlayer film forming composition according to [8], wherein the curing catalyst (E) is a thermal acid generator.

[10] A resist underlayer film formation composition according to any one of [1] to [9], used in an EUV (extreme ultraviolet) exposure process.

[11] A resist underlayer film, which is a cured product of the resist underlayer film formation composition according to any one of [1] to

[10] .

[12] A laminate comprising a semiconductor substrate and the resist underlayer film according to

[11] .

[13] A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer on a semiconductor substrate using a resist underlayer forming composition according to any one of [1] to

[10] ; and forming a metal-containing resist film on the resist underlayer.

[14] A method for forming a pattern, comprising the steps of: forming a resist underlayer on a semiconductor substrate using a resist underlayer forming composition according to any one of [1] to

[10] ; forming a metal-containing resist film on the resist underlayer; irradiating the metal-containing resist film with an electron beam or EUV, then developing the metal-containing resist film to obtain a resist pattern; and etching the resist underlayer using the resist pattern as a mask.

[0008] According to the present invention, it is possible to provide a resist underlayer film formation composition that can form resist patterns with high sensitivity, as well as a method for manufacturing a resist underlayer film, a laminate, a semiconductor device, and a pattern formation method using the resist underlayer film formation composition.

[0009] (Composition for forming a resist underlayer film) The resist underlayer film formation composition of the present invention is a composition for forming a resist film that is formed between a metal-containing resist film and a substrate. The resist underlayer film formation composition comprises a resin (A), a photobase generator (B), and a solvent (C). The resist underlayer film formation composition may also contain a crosslinking agent (D), a curing catalyst (E), etc. The resist underlayer film formation composition may be used in EUV lithography. EUV refers to extreme ultraviolet light with a wavelength of 13.5 nm.

[0010] The sensitivity of the resist pattern can be improved by including a photobase generator (B) in the resist underlayer film formation composition.

[0011] <Resin (A)> Resin (A) is not particularly limited as long as it can harden and form a resist underlayer film. Examples of resin (A) include poly(meth)acrylic resin, polyester resin, polyether resin, polyvinyl resin, resin having an isocyanuric acid structure, resin having a barbituric acid structure, resin having a hydantoin structure, etc. Here, poly(meth)acrylic resin refers to both or either polyacrylic resin and polymethacrylic resin.

[0012] <<Poly(meth)acrylic resin>> Examples of poly(meth)acrylic resins include resins having structural units represented by the following formula (A-1a).

[0013] (In formula (A-1a), R １ L represents a hydrogen atom or a methyl group. １ L represents a single bond or a linking group. ２ (This represents a monovalent group.)

[0014] L １ When it is a linking group, there are no particular restrictions on the number of carbon atoms in the linking group, but for example, 1 to 10 can be cited. １ When a linking group is present, examples of linking groups include those having a structure obtained by the reaction of an epoxy group with a nucleophilic functional group, and those having a structure obtained by the reaction of an isocyanate group with a nucleophilic functional group.

[0015] Examples of nucleophilic functional groups include one or more selected from the group consisting of carboxyl groups, hydroxyl groups, amino groups, and thiol groups. The hydroxyl group may or may not be a phenolic hydroxyl group. When the epoxy group and the carboxyl group react, they react as follows to form the following structure (S1).

[0016] (In the formula, * represents a bond.)

[0017] Also, in the case of a linking group having a structure obtained by reacting an isocyanate group with a nucleophilic functional group, examples of the nucleophilic functional group include one or more selected from the group consisting of a hydroxy group, an amino group, and a thiol group. The hydroxy group may be a phenolic hydroxy group or may not be a phenolic hydroxy group.

[0018] L １ Examples of L include the following linking groups (L1-1) to (L1-11).

[0019] (In the formula, *1 represents a bond that binds to the carbon atom to which R in formula (A-1a) binds. *2 represents a bond that binds to L in formula (A-1a).)

[0020] L ２ is a monovalent group. The number of carbon atoms of the monovalent group is not particularly limited, and for example, it may be 1 to 20 or may be 1 to 10. L ２ may be a monovalent group having a polymerizable multiple bond, and the monovalent group may be the polymerizable multiple bond itself.

[0021] The polymerizable multiple bond is one or more polymerizable multiple bonds 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.

[0022] L ２ Examples of L include the following monovalent groups (L2-1) to (L2-25).

[0023] <​​​​​​​​​​​​​​​​​１ -L ２ It is preferable that it has a structure represented by the following formulas (1a), (1b), or (1c).

[0027] (In formulas (1a) to (1c), R ２ * represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. *a and *b represent bonding sites, where *a is the main chain side of the poly(meth)acrylic resin and *b is the terminal side of the side chain of the poly(meth)acrylic resin. Note that *b may also be a bonding site with a hydrogen atom.

[0028] Examples of alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, and 1-ethyl-n-propyl group. 1,1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2, 2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2Examples include 3-trimethylcyclopropyl group, 1-ethyl-2-methylcyclopropyl group, 2-ethyl-1-methylcyclopropyl group, 2-ethyl-2-methylcyclopropyl group, 2-ethyl-3-methylcyclopropyl group, n-heptyl group, cycloheptyl group, norbornyl group, n-octyl group, cyclooctyl group, n-nonyl group, isobornyl group, tricyclononyl group, n-decyl group, adamantyl group, tricyclodecyl group, etc.

[0029] Examples of structural units represented by formula (A-1a) include the following:

[0030]

[0031] An example of a poly(meth)acrylic resin containing the structural unit represented by formula (A-1a) can be obtained, for example, by reacting a glycidyl (meth)acrylate polymer with a compound (C1) having a carboxyl group, as shown below. The glycidyl (meth)acrylate polymer may be a homopolymer or a copolymer. Examples of copolymers include copolymers of glycidyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate, and copolymers of glycidyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0032] (In the formula, R １ , and L ２ These are R in equation (A-1a), respectively. １ , and L ２ (This is synonymous with...)

[0033] The reaction can be carried out in the presence of a catalyst, such as tetrabutylphosphonium bromide.

[0034] Examples of compounds having a carboxyl group (C1) include acetic acid, propanoic acid, butanoic acid, hexanoic acid, benzoic acid, salicylic acid, acrylic acid, methacrylic acid, 4-vinylbenzoic acid, sorbic acid, tetrolic acid, tigric acid, 1-cyclohexen-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.

[0035] Another example of a poly(meth)acrylic resin containing the structural unit represented by formula (A-1a) can be obtained, for example, by reacting a (meth)acrylate polymer having a hydroxyl group with a compound (C2) having an isocyanate group, as shown below. The (meth)acrylate polymer having a hydroxyl group may be a homopolymer or a copolymer.

[0036] (In the formula, R １ , and L ２ These are R in equation (A-1a), respectively. １ , and L ２ This is synonymous with R. １１ R represents a divalent organic group. １２ (This represents a single bond or a divalent organic group.)

[0037] R １１ For example, an alkylene group has 1 to 4 carbon atoms. １２ These are, for example, single bonds or alkylene groups having 1 to 4 carbon atoms.

[0038] Another example of a poly(meth)acrylic resin containing the structural unit represented by formula (A-1a) can be obtained, for example, by reacting a styrene-based polymer having a hydroxyl group or an amino group with a compound (C2) having an isocyanate group, as shown below. The styrene-based polymer having a hydroxyl group or an amino group may be a homopolymer or a copolymer.

[0039] (In the formula, R １ , and L ２ These are R in equation (A-1a), respectively.１ , and L ２ This is synonymous with R. １２ (This represents a single bond or a divalent organic group.)

[0040] R １２ These are, for example, single bonds or alkylene groups having 1 to 4 carbon atoms.

[0041] Examples of compounds (C2) having an isocyanate group include the following:

[0042]

[0043] The poly(meth)acrylic resin may be a homopolymer having one type of structural unit, or a copolymer having two or more types of structural units.

[0044] There are no particular restrictions on the proportion of structural units represented by formula (A-1a) in poly(meth)acrylic resin, but the molar ratio of structural units represented by formula (A-1a) to the total structural units of poly(meth)acrylic resin may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0045] The poly(meth)acrylic resin may contain structural units other than those represented by formula (A-1a). In that case, the molar ratio of the other structural units to the total structural units of the poly(meth)acrylic resin is preferably, for example, greater than 0 mol% and 90 mol% or less, greater than 0 mol% and 80 mol% or less, greater than 0 mol% and 70 mol% or less, greater than 0 mol% and 60 mol% or less, greater than 0 mol% and 50 mol% or less, greater than 0 mol% and 40 mol% or less, greater than 0 mol% and 30 mol% or less, greater than 0 mol% and 20 mol% or less, greater than 0 mol% and 10 mol% or less, greater than 0 mol% and 5 mol% or less, or greater than 0 mol% and 1 mol% or less.

[0046] The molecular weight of the poly(meth)acrylic resin is not particularly limited. The lower limit of the weight-average molecular weight of the poly(meth)acrylic resin is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight-average molecular weight of the poly(meth)acrylic resin is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000. In this specification, the weight-average molecular weight (Mw) is the polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0047] <<Polyvinyl Resin>> Examples of polyvinyl resins include resins having at least one of the structural units represented by the following formula (A-1b) and the following formula (A-1c).

[0048] (In formula (A-1b), R １ Ar represents a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. １ L represents a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, or pyrene ring. １ L represents a hydroxyl group, cyano group, nitro group, amino group, alkylamino group, carboxyl group, formyl group, acyl group, sulfonyl-containing group, ether-bonded group, thiol group, or ester group. ２ m1 represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms. The hydrogen atoms of these aryl groups may be substituted with alkyl groups, alkenyl groups, or alkynyl groups, and the carbon-carbon bonds of these substituted alkyl groups, alkenyl groups, or alkynyl groups may be broken by oxygen atoms. m1 represents an integer from 0 to 3. m2 represents an integer from 0 to 5. However, the sum of m1 and m2 is from 0 to 5. If m1 is 2 or 3, multiple L １ They may be the same or different. If m2 is 2 to 5, multiple L ２ R may be the same or different. In equation (A-1c), １L represents a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. ３ and L ４ Each of these independently represents a hydrogen atom or a monovalent group.

[0049] L １ The alkylamino group in this case is -NHR or -NR ２ A group represented by is an example. Here, R may be interrupted once or more by an oxygen atom in the middle of the hydrocarbon chain, and may be substituted with a hydroxyl group or a halogen atom, a saturated or unsaturated linear, branched or cyclic hydrocarbon group (-R ａ ) represents R ａ Examples include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and aryl groups having 6 to 30 carbon atoms. -NR ２ In this case, the two Rs may be the same or different. １ Examples of acyl groups in this context include groups represented by -COR, where R is the hydrocarbon group -R ａ Or it represents a halogen atom. L １ The sulfonyl-containing group in this is -SO ２ A group represented by R is an example. Here, R is the hydrocarbon group -R which may be substituted with a hydroxyl group or a halogen atom. ａ , represents an alkylamino group or a hydroxyl group. L １ As for the ether bond-containing group in R, １１ -O-R １１ Examples include residues of ether compounds containing an ether bond represented by . Here, R １１ Each of these independently represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group, or an aryl group, such as a phenyl group, a naphthyl group, anthranyl group, or a pyrenyl group. The ether bond-containing group may be an organic group containing an ether bond, such as a methoxy group, an ethoxy group, or a phenoxy group, or an organic group containing an epoxy group or an oxetane group. １ The ester group in this is -CO ２Examples of groups represented by R or -OCOR include the hydrocarbon group -R, where R may be substituted with a hydroxyl group or a halogen atom. ａ It represents.

[0050] L ２ In this context, the halogen atom, alkyl group, alkenyl group, and alkynyl group are R １ Examples include halogen atoms, alkyl groups, alkenyl groups, and atoms or groups similar to alkynyl groups in L. ２ Examples of alkoxy groups having 1 to 10 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentyloxy, allyloxy, cyclohexyloxy, phenoxy, benzyloxy, and 1-naphthyloxy groups. m1 represents an integer from 0 to 3, and may be 0, 1, 2, or 3. m2 represents an integer from 0 to 5, and may be 0, 1, 2, 3, 4, or 5.

[0051] L in equation (A-1c) ３ and L ４ Each of these is independently a hydrogen atom or a monovalent group. ３ and L ４ Examples of monovalent groups in this context include alkyl groups having 1 to 10 carbon atoms, phenyl groups, benzyl groups, sulfo groups, etc. ３ and L ４ One or more hydrogen atoms in the monovalent group may be substituted with substituents. Examples of such substituents include halogen atoms, hydroxyl groups, cyano groups, nitro groups, amino groups, isocyanate groups, carboxyl groups, formyl groups, acyl groups, thiol groups, methyl groups, ethyl groups, and the like. ３ and L ４ The monovalent group may be separated by one or more atoms or groups selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and carbonyl groups, or it may form a ring structure bonded by one or more atoms or groups selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and carbonyl groups.

[0052] Examples of monomers used to derive formula (A-1b) include the following compounds. In the formula, R １ represents a hydrogen atom or a methyl group.

[0053]

[0054] Examples of monomers used to derive formula (A-1c) include the following compounds. In the formula, R １ represents a hydrogen atom or a methyl group.

[0055]

[0056] The polyvinyl resin may be a homopolymer having one type of structural unit, or a copolymer having two or more types of structural units.

[0057] There are no particular restrictions on the proportion of structural units represented by formula (A-1b) or formula (A-1c) in the polyvinyl resin. However, the molar ratio of structural units represented by formula (A-1b) or formula (A-1c) to the total structural units of the polyvinyl resin may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0058] The polyvinyl resin may contain structural units other than those represented by formula (A-1b) and formula (A-1c). In this case, the molar ratio of the other structural units to the total structural units of the polyvinyl resin is preferably, for example, greater than 0 mol% and 90 mol% or less, greater than 0 mol% and 80 mol% or less, greater than 0 mol% and 70 mol% or less, greater than 0 mol% and 60 mol% or less, greater than 0 mol% and 50 mol% or less, greater than 0 mol% and 40 mol% or less, greater than 0 mol% and 30 mol% or less, greater than 0 mol% and 20 mol% or less, greater than 0 mol% and 10 mol% or less, greater than 0 mol% and 5 mol% or less, or greater than 0 mol% and 1 mol% or less.

[0059] The molecular weight of the polyvinyl resin is not particularly limited. The lower limit of the weight-average molecular weight of the polyvinyl resin is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight-average molecular weight of the polyvinyl resin is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000.

[0060] <<Polyester resin or polyether resin>> Examples of polyester resins or polyether resins include resins having structural units represented by the following formula (A-2).

[0061] (In formula (A-2), A independently represents a hydrogen atom, a methyl group, or an ethyl group, and Q １ and Q ２ Each of these independently represents a divalent organic group, X １ ~X ４ These terms independently represent either an ether bond or an ester bond.

[0062] Q １ and Q ２ The number of carbon atoms is not particularly limited; for example, it may be 1 to 50, 3 to 40, or 6 to 30. １ ~X ４ If it is an ester bond, X １ and X ３ -OCO- is preferred, X ２ and X ４ -COO- is preferred.

[0063] Q １ and Q ２Examples of the divalent organic group include an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 20 carbon atoms, an alkynylene group having 2 to 20 carbon atoms, an aryl group having 6 to 50 carbon atoms, and the like. At least one hydrogen atom of these organic groups may be substituted with a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a cyano group, a nitro group, an amino group, an alkylamino group, an isocyanate group, an alkyl isocyanate group, a carboxy group, a formyl group, an acyl group, a sulfonyl-containing group, an ether bond-containing group, a thiol group, an ester group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and the like. Also, Q １ and Q ２ The divalent organic groups of Q

[0064] and Q １ may be divided by one or more atoms or groups selected from a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a carbonyl group, may be branched, or may form a ring structure bonded by one or more atoms or groups selected from a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a carbonyl group.

[0064] In formula (A-2), Q １ or Q ２ Examples of the structure include those exemplified below. In the formula, * represents a bond.

[0065]

[0066] The polyester resin or polyether resin may further have a monovalent group represented by the following formula (E). The monovalent group represented by formula (E) is, for example, located at the terminal of the polyester resin or polyether resin. [[ID=2�]]

[0067] (In formula (E), p represents 0 or 1. Z represents a monovalent group having 1 to 20 carbon atoms. * represents a bond.)

[0068] As Z, a monovalent organic group having 1 to 20 carbon atoms similar to R in the formula (A-1b) of the above-described <<polyvinyl resin>> can be mentioned. The number of carbon atoms of Z is preferably 6 to 20. Z has, for example, an aromatic hydrocarbon ring. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, etc. For example, in the formula (E), Z has an aromatic hydrocarbon ring, and the carbon atoms constituting the aromatic hydrocarbon ring are bonded to the carbonyl carbon atom in the formula (E). １ As Z in the formula (E), for example, a group represented by the following formula (E-1) can be mentioned.

[0069]

[0070] (In the formula (E-1), q represents an integer of 0 to 2. r represents an integer of 0 to 4. R each independently represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. * represents a bond.) ｂ

[0071] As the monovalent group represented by the formula (E), for example, the following groups can be mentioned.

[0072] * represents a bond.

[0073] The polyester resin or the polyether resin can be synthesized, for example, by the following method. (I): Reaction of a compound represented by the following formula (1A) and a compound represented by the following formula (1B). (II): Reaction of a compound represented by the following formula (1A), a compound represented by the following formula (1B), and a compound represented by the following formula (EA).

[0074] (In the formula (1A), Q １ , X １ and X ２ are synonymous with Q １ , X １ and X ２ in the formula (A-2), respectively. In the formula (1B), A, Q ２ , X ３ and X ４ are A, Q ２ , X３ and X ４ These are equivalent to the terms in equation (EA). In equation (EA), p and Z are equivalent to the terms in equation (E).

[0075] The above reaction may be carried out, for example, in the presence of a catalyst. Examples of catalysts include quaternary phosphonium salts such as tetrabutylphosphonium bromide and ethyltriphenylphosphonium bromide, and quaternary ammonium salts such as benzyltriethylammonium chloride. The amount of catalyst used can be selected from a range of 0.1 to 10% by mass relative to the total mass of the reaction materials used in the reaction. The reaction temperature and time can be selected from the range of 50 to 160°C and 2 to 50 hours, for example, to find the optimal conditions.

[0076] The polyether resin may contain a resin having a structural unit represented by the following formula (A-3) (hereinafter also referred to as "resin (A-3)").

[0077] (In formula (A-3), T ３ Q represents a group having a monocyclic aliphatic ring that constitutes the main chain. ３ represents a divalent linking group, Ar ３ (This represents an aromatic hydrocarbon ring which may have substituents.)

[0078] The resin (A-3) is Ar in formula (A-3). ３ It may have two or more different structural units represented by formula (A-3).

[0079] Examples of monocyclic aliphatic rings include cycloalkane rings having 4 to 10 carbon atoms. Among these, the cyclohexane ring is preferred.

[0080] A monocyclic aliphatic ring is represented by -Q in formula (A-3). ３ -Ar ３Other substituents may be present. Examples of substituents include halogen atoms, C1-C20 alkyl groups, C2-C10 alkenyl groups, C2-C10 alkynyl groups, C1-C20 alkoxy groups, C6-C30 aryl groups, C6-C30 aryloxy groups, amino groups, hydroxyl groups, C1-C20 hydroxyalkyl groups, carboxyl groups, formyl groups, cyano groups, nitro groups, ester groups, amide groups, sulfonyl-containing groups, thiol groups, sulfide-containing groups, or ether-bond-containing groups.

[0081] Examples of alkyl groups having 1 to 20 carbon atoms include the alkyl groups exemplified in <<poly(meth)acrylic resin>>. Examples of alkenyl groups having 2 to 10 carbon atoms include the alkenyl groups exemplified in <<poly(meth)acrylic resin>>. Examples of alkynyl groups having 2 to 10 carbon atoms include the alkynyl groups exemplified in <<poly(meth)acrylic resin>>. Examples of alkoxy groups having 1 to 20 carbon atoms include the alkoxy groups exemplified in <<poly(meth)acrylic resin>>.

[0082] Examples of aryl groups having 6 to 30 carbon atoms include phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-fluorophenyl group, p-fluorophenyl group, o-methoxyphenyl group, p-methoxyphenyl group, p-nitrophenyl group, p-cyanophenyl group, α-naphthyl group, β-naphthyl group, o-biphenylyl group, m-biphenylyl group, p-biphenylyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, and 9-phenanthryl group.

[0083] Examples of aryloxy groups having 6 to 30 carbon atoms include phenoxy, benzyloxy, and 1-naphthyloxy groups. Examples of hydroxyalkyl groups having 1 to 20 carbon atoms include groups in which at least one hydrogen atom of the alkyl group having 1 to 20 carbon atoms is substituted with a hydroxyl group. Examples of ester groups include -CO ２ Examples include groups represented by R or -OCOR. Here, R may be substituted with a hydroxyl group or a halogen atom, or the hydrocarbon group -R ａ This represents the amide group, which can be -NHCOR, -CONHR, -NRCOR, or -CONR. ２ A group represented by is shown. Here, R may be substituted with a hydroxyl group or a halogen atom, the hydrocarbon group -R ａ This represents a group, and if there are two Rs, the two Rs may be the same or different. Examples of sulfonyl-containing groups include -SO ２ A group represented by R is an example. Here, R may be substituted with a hydroxyl group or a halogen atom, the hydrocarbon group -R ａ , represents an alkylamino group or a hydroxyl group. Examples of sulfide-containing groups include groups represented by -SR. Here, R may be substituted with a hydroxyl group or a halogen atom, the hydrocarbon group -R ａ This represents the ether bond-containing group, R １１ -O-R １１ Examples include residues of ether compounds containing an ether bond represented by . Here, R １１ Each of these independently represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group, or an aryl group, such as a phenyl group, a naphthyl group, anthranyl group, or a pyrenyl group. The ether bond-containing group may be an organic group containing an ether bond, such as a methoxy group, an ethoxy group, or a phenoxy group, or an organic group containing an epoxy group or an oxetane group.

[0084] As the structural unit represented by formula (A-3), the structural unit represented by the following formula (Xa) is preferred.

[0085] (In equation (Xa), R ３This represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen atom, a nitro group, or an amino group. Q ３ Ar represents a divalent linking group. ３ (This represents an aromatic hydrocarbon ring which may have substituents.)

[0086] Ar in equations (A-3) and (Xa) ３ The aromatic hydrocarbon ring in this can be a monoring or a fused ring. Examples of aromatic hydrocarbon rings include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, pyrene rings, and so on.

[0087] Ar in equations (A-3) and (Xa) ３ Examples of substituents that may be present include halogen atoms, alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, aryl groups having 6 to 30 carbon atoms, aryloxy groups having 6 to 30 carbon atoms, amino groups, hydroxyl groups, hydroxyalkyl groups having 1 to 20 carbon atoms, carboxyl groups, formyl groups, cyano groups, nitro groups, ester groups, amide groups, sulfonyl-containing groups, thiol groups, sulfide-containing groups, or ether-bond-containing groups.

[0088] Q in equations (A-3) and (Xa) ３ The number of atoms constituting the divalent linking group in this compound can range from 1 to 60, for example.

[0089] Q ３ Examples include the following linking group (Qa).

[0090] (In equation (Qa), X ５ *1 represents a single bond or carbonyl group. *2 represents a bond with an aromatic hydrocarbon ring.

[0091] The resin (A-3) is, for example, a reaction product of a polymer (X1) having repeating units represented by the following formula (X1) and an aromatic carboxylic acid (X2) or a phenol compound (X3).

[0092] (In formula (X1), R ３ (This represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen atom, a nitro group, or an amino group.)

[0093] The polymer having repeating units represented by formula (X1) may be a commercially available product. Examples of commercially available products include EHPE3150 (manufactured by Daicel Chemical Industries, Ltd.).

[0094] Examples of aromatic carboxylic acids (X2) include monocyclic aromatic carboxylic acids and fused-ring aromatic carboxylic acids. Examples of monocyclic aromatic carboxylic acids include benzoic acid. Examples of fused-ring aromatic carboxylic acids include naphthalene carboxylic acid and anthracene carboxylic acid. Examples of phenol compounds (X3) include any compound having a phenolic hydroxyl group, such as phenol, 1-naphthol, 2-naphthol, anthracene-1-ol, anthracene-2-ol, anthracene-9-ol, and 1-hydroxypyrene.

[0095] Examples of resin (A-3) include the following polymers (X-1) to (X-13). The following polymers have two, three, or four repeating units.

[0096]

[0097] The proportion of structural units represented by formula (A-2) in the polyester resin or polyether resin is not particularly limited, but the molar ratio of structural units represented by formula (A-2) to the total structural units of the polyester resin or polyether resin may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0098] The polyester resin or polyether resin may contain structural units other than the structural unit represented by formula (A-2). In that case, the molar ratio of the other structural units to the total structural units of the polyester resin or polyether resin is preferably, for example, greater than 0 mol% and 90 mol% or less, greater than 0 mol% and 80 mol% or less, greater than 0 mol% and 70 mol% or less, greater than 0 mol% and 60 mol% or less, greater than 0 mol% and 50 mol% or less, greater than 0 mol% and 40 mol% or less, greater than 0 mol% and 30 mol% or less, greater than 0 mol% and 20 mol% or less, greater than 0 mol% and 10 mol% or less, greater than 0 mol% and 5 mol% or less, or greater than 0 mol% and 1 mol% or less.

[0099] The weight-average molecular weight of the polyester resin or polyether resin is not particularly limited, but is preferably 1,000 to 30,000, more preferably 2,000 to 20,000, and particularly preferably 2,500 to 15,000.

[0100] <<Resin having an isocyanuric acid structure, a barbituric acid structure, or a hydantoin structure>> Examples of resins having an isocyanuric acid structure, a barbituric acid structure, or a hydantoin structure include resins having a structural unit represented by the following formula (A-4) (hereinafter also referred to as "resin (A-4)").

[0101] (In formula (A-4), A independently represents a hydrogen atom, a methyl group, or an ethyl group, and Q １ and Q ２ Each of these independently represents a divalent organic group, Q １ and Q ２ Both or either of them have a structure represented by the following formula (A-4-3), X １ ~X ４ These terms independently represent a single bond, an ether bond, or an ester bond. (In formula (A-4-3), X １１ represents a divalent group represented by any of the following formulas (A-4-3a) to (A-4-3c). * represents a bond. (In formulas (A-4-3a) to (A-4-3c), R １ ~R５ Each independently represents a C1-C10 alkyl group that may be interrupted by a hydrogen atom, an oxygen atom, or a sulfur atom, a C2-C10 alkenyl group that may be interrupted by an oxygen atom or a sulfur atom, a C2-C10 alkynyl group that may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and at least one hydrogen atom of the benzyl group or phenyl group may be substituted with at least one monovalent group selected from the group consisting of C1-C6 alkyl groups, halogen atoms, C1-C6 alkoxy groups, nitro groups, cyano groups, and C1-C6 alkylthio groups. １ and R ２ These may be bonded to each other to form a ring with 3 to 6 carbon atoms. ３ and R ４ These atoms may bond to each other to form a ring with 3 to 6 carbon atoms. * represents a bond. *1 represents a bond to the carbon atom in formula (A-4-3). *2 represents a bond to the nitrogen atom in formula (A-4-3).

[0102] Q in equation (A-4) １ Or Q ２ As for Q in formula (A-2) of the above-mentioned <<polyester resin or polyether resin>> １ Or Q ２ Similar divalent organic groups can be cited.

[0103] Q in equation (A-4) １ Or Q ２ For example, the following structure is given as an illustration. In the formula, * represents a coupling.

[0104]

[0105] The resin (A-4) can be synthesized, for example, by the following methods: (I): Reaction of a compound represented by formula (2A) below with a compound represented by formula (2B) below. (II): Reaction of a compound represented by formula (2A) below with a compound represented by formula (2B) below with a compound represented by formula (EA) below.

[0106] (In formula (2A), Q１ , X １ and X ２ Q in equation (A-4) is １ , X １ and X ２ These are synonymous. In equation (2B), A and Q ２ , X ３ and X ４ A and Q in equation (A-4) are ２ , X ３ and X ４ These are synonymous. In formula (EA), p represents 0 or 1, and Z represents a monovalent group with 1 to 20 carbon atoms.

[0107] Z is R in the formula (A-1b) of the above-mentioned polyvinyl resin. １ Similar monovalent organic groups having 1 to 20 carbon atoms can be cited. The number of carbon atoms in Z is preferably 6 to 20. Z has, for example, an aromatic hydrocarbon ring. Examples of aromatic hydrocarbon rings include a benzene ring, a naphthalene ring, an anthracene ring, and the like.

[0108] The above reaction may be carried out, for example, in the presence of a catalyst. Examples of catalysts include quaternary phosphonium salts such as tetrabutylphosphonium bromide and ethyltriphenylphosphonium bromide, and quaternary ammonium salts such as benzyltriethylammonium chloride. The amount of catalyst used can be selected from a range of 0.1 to 10% by mass relative to the total mass of the reaction materials used in the reaction. The reaction temperature and time can be selected from the range of 50 to 160°C and 2 to 50 hours, for example, to find the optimal conditions.

[0109] The proportion of structural units represented by formula (A-4) in a resin having an isocyanuric acid structure, a resin having a barbituric acid structure, or a resin having a hydantoin structure is not particularly limited. However, the molar ratio of structural units represented by formula (A-4) to the total structural units of the resin having an isocyanuric acid structure, a resin having a barbituric acid structure, or a resin having a hydantoin structure may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0110] A resin having an isocyanuric acid structure, a resin having a barbituric acid structure, or a resin having a hydantoin structure may contain structural units other than the structural unit represented by formula (A-4). In that case, the molar ratio of the other structural units to the total structural units of the resin having an isocyanuric acid structure, a resin having a barbituric acid structure, or a resin having a hydantoin structure is preferably, for example, greater than 0 mol% and 90 mol% or less, greater than 0 mol% and 80 mol% or less, greater than 0 mol% and 70 mol% or less, greater than 0 mol% and 60 mol% or less, greater than 0 mol% and 50 mol% or less, greater than 0 mol% and 40 mol% or less, greater than 0 mol% and 30 mol% or less, greater than 0 mol% and 20 mol% or less, greater than 0 mol% and 10 mol% or less, greater than 0 mol% and 5 mol% or less, or greater than 0 mol% and 1 mol% or less.

[0111] The weight-average molecular weight of resin (A-4) is not particularly limited, but is preferably 1,000 to 30,000, more preferably 2,000 to 20,000, and particularly preferably 2,500 to 15,000.

[0112] The content of resin (A) in the resist underlayer film forming composition is not particularly limited, but is preferably 30% to 95% by mass, more preferably 50% to 90% by mass, and particularly preferably 60% to 85% by mass relative to the film constituent components in the resist underlayer film forming composition. Film constituent components refer to components in the resist underlayer film forming composition other than the solvent.

[0113] <Photobase Generator (B)> Photobase generator (B) is a compound that generates a base when the resist is exposed. The resist underlayer film forming composition of this embodiment can improve the sensitivity of the resist pattern by containing photobase generator (B).

[0114] Photobase generators (B) can be classified into ionic photobase generators and nonionic photobase generators. Examples of ionic photobase generators include compounds represented by the following formulas (B-1a) to (B-1d).

[0115] (In formula (B-1a), R １ ~R ４ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X １Each of these independently represents a halogen atom. n represents an integer from 0 to 5. (In formula (B-1b), R ５ ~R ７ Each of these independently represents an alkyl group having 1 to 3 carbon atoms, X １ Each of these independently represents a halogen atom. n represents an integer from 0 to 5. ５ and R ６ These may be bonded to each other to form a ring with 3 to 6 carbon atoms. ６ and R ７ These may be bonded to each other to form a ring with 3 to 6 carbon atoms. (In formula (B-1c), R ８ ~R １１ Each of these independently represents an alkyl group having 1 to 3 carbon atoms, and R １２ and R １３ Each of these independently represents an alkyl group having 1 to 8 carbon atoms, X １ Each of these independently represents a halogen atom. n represents an integer from 0 to 5. (In formula (B-1d), R １４ ~R １７ Each of these independently represents an alkyl group having 1 to 3 carbon atoms, X １ Each of these independently represents a halogen atom. n represents an integer from 0 to 5. １４ and R １５ These may be bonded to each other to form a ring with 3 to 6 carbon atoms. １６ and R １７ These may be bonded to each other to form a ring with 3 to 6 carbon atoms.

[0116] In formulas (B-1a) to (B-1d), examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. １ A fluorine atom is preferred as the element. In formulas (B-1a) to (B-1d), n is preferably 0 to 3. In formula (B-1a), R １ ~R ４ A methyl group is preferred as the component. In formula (B-1b), R ５ and R ６It is preferable that they are bonded to each other to form a ring with 5 carbon atoms. ６ and R ７ Preferably, they are bonded to each other to form a ring with 5 carbon atoms. In formula (B-1c), R ８ ~R １１ A methyl group is preferred. １２ A cyclohexylmethyl group is preferred. １３ A cyclohexyl group is preferred. In formula (B-1d), R １４ and R １５ It is preferable that they are bonded to each other to form a ring with 6 carbon atoms. １６ and R １７ Preferably, these elements are bonded to each other to form a ring with 4 carbon atoms.

[0117] Examples of cation structures for the compound represented by formula (B-1a) include the following:

[0118] Examples of cation structures for the compound represented by formula (B-1b) include the following:

[0119] Examples of cation structures for the compound represented by formula (B-1c) include the following:

[0120] Examples of cation structures for the compound represented by formula (B-1d) include the following:

[0121] Examples of ionic photobase generators include (Z)-{[bis(dimethylamino)methylidene]amino}-N-cyclohexyl(cyclohexylamino)methaneiminium=tetrakis(3-fluorophenyl)borate, N-(2'-phenylallyl)-triethylammonium tetraphenylborate, 1-(2'-phenylallyl)-(1-azonia-4-azabicyclo[2,2,2]-octane)tetraphenylborate, 1-(2'-phenylallyl)-(1-azonia-4-azabicyclo[2,2,2]- (2,2,2)-octane)tetraphenylborate, phenacyltriethylammonium tetraphenylborate, (4-methoxyphenacyl)triethylammonium tetraphenylborate, 1-phenacyl-(1-azonia-4-azabicyclo[2,2,2]-octane)tetraphenylborate, (1,4-phenacyl-1,4-diazoniabicyclo[2,2,2]octane)bis(tetraphenylborate), 1-naphthoylmethyl-(1-azonia-4-azabicyclo[2,2,2)-octane)tetraphenylborate, 1-(4'-phenyl)phenacyl-(1-azonia-4-azabicyclo[2.2.2]octane)tetraphenylborate, 5-(4'-phenyl)phenacyl-(5-azonia-1-azabicyclo[4.3.0]-5-nonene)tetraphenylborate, 5-(4'-methoxy)phenacyl-(5-azonia-1-azabicyclo[4.3.0]-5-nonene)tetraphenylborate, 5-(4'-nitro)phenacyl-(5-azonia-1-azabicyclo[4.3.0]-5 -nonene)tetraphenylborate, 5-(4'-phenyl)phenacyl-(8-azonia-1-azabicyclo[5.4.0]-7-undecene)tetraphenylborate, (9-anthryl)methyltriethylammonium tetraphenylborate, (9-oxo-9H-thioxanthene-2-yl)methyltriethylammonium tetraphenylborate, (9-anthryl)methyl-1-azabicyclo[2.2.2]octanium tetraphenylborate, (9-oxo-9H-thioxanthene-2-yl)methyl-1-azabicyclo Bicyclo[2.2.2]octaniumtetraphenylborate, 9-anthrylmethyl-1-azabicyclo[2.2.2]octaniumtetraphenylborate, 5-(9-anthrylmethyl)-1,5-diazabicyclo[4.3.0]-5-noneniumtetraphenylborate, N-(9-anthrylmethyl)-N,N,N-trioctylammoniumtetraphenylborate, 8-(9-oxo-9H-thioxanthene-2-yl)methyl-1,5-diazabicyclo[4.3.0]-5-noneniumtetraphenylborate Examples include 8-(4-benzoylphenyl)methyl-1,8-diazabicyclo[5.4.0]-7-undecenium tetraphenylborate, {8-(t-butyl-2-naphthalylmethyl)-1,8-diazabicyclo[5.4.0]-7-undecenium tetraphenylborate, 8-(9-oxo-9H-thioxanthene-2-yl)methyl-1,8-diazabicyclo[5.4.0]-7-undecenium tetraphenylborate, N-benzophenonemethyltri-N-methylammonium tetraphenylborate, etc.

[0122] Examples of preferred compounds as ionic photobase generators include compounds represented by the following structural formula.

[0123] Examples of nonionic photobase generators include compounds represented by the following formula (B-2a).

[0124] (In formula (B-2a), R ２１ and R ２２ Each of these independently represents an alkyl group having 1 to 3 carbon atoms, X ２ Each of these independently represents a hydroxyl group or a halogen atom. n represents an integer from 0 to 5. ３１ and R ３２ These may be bonded to each other to form a ring with 3 to 6 carbon atoms.

[0125] In formula (B-2a), examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. ２ A hydroxyl group is preferred. In formula (B-2a), n is preferably 0 to 3, and more preferably 1 to 2. In formula (B-2a), R ２１ and R ２２ Preferably, these atoms are bonded to each other to form a ring with 5 carbon atoms.

[0126] As a nonionic photobase generator, (E)-1-piperidino-3-(2-hydroxyphenyl)-2-propen-1-one, represented by the following structural formula, is preferred.

[0127] Furthermore, the photobase generator (B) may be a commercially available product, and specific examples include (Z)-{[bis(dimethylamino)methylidene]amino}-N-cyclohexyl(cyclohexylamino)methaneiminium=tetrakis(3-fluorophenyl)borate (manufactured by Fujifilm Wako Pure Chemical Corporation, WPBG-345), 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium=2-(3-benzoylphenyl)propionate (manufactured by Fujifilm Wako Pure Chemical Corporation, WPBG-266), N,N-diethylcarbamate 9-anthrylmethyl (manufactured by Fujifilm Wako Pure Chemical Corporation, WPBG-018), N-cyclohexylcarbamate 1-(anthraquinone-2-yl)ethyl (manufactured by Fujifilm Wako Pure Chemical Corporation, WPBG-174), piperidine-1-carboxylic acid 9- Anthrylmethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-015), 9-anthrylmethyl N,N-dicyclohexylcarbamate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-172), imidazole-1-carboxylic acid 1-(anthraquinone-2-yl)ethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-140), cyclohexylammonium 2-(3-benzoylphenyl)propionate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-168), (E)-N-cyclohexyl-3-(2-hydroxyphenyl)acrylamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-025), dicyclohexylammonium 2-(3-benzoylphenyl)propionate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-167), 1,2-dicyclohexyl-4,4,5,Examples include 5-tetramethylbiguanidium-n-butyltriphenyl borate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-300), 4-hydroxypiperidine-1-carboxylic acid (2-nitrophenyl)methyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-158), 4-(methacryloyloxy)piperidine-1-carboxylic acid (2-nitrophenyl)methyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-165), guanidium 2-(3-benzoylphenyl)propionate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-082), and (E)-1-piperidino-3-(2-hydroxyphenyl)-2-propen-1-one (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., WPBG-027).

[0128] The resist underlayer film forming composition of this embodiment may contain base generators other than the photobase generator (B). Examples of base generators other than the photobase generator (B) include thermal base generators, such as DBU (diazabicycloundecene) phenol salt (manufactured by Sunapro Co., Ltd.).

[0129] From the viewpoint of favorably obtaining the effects of the present invention, the content of the photobase generator (B) is preferably 5 to 30 parts by mass, more preferably 5 to 15 parts by mass, and even more preferably 5 to 10 parts by mass, per 100 parts by mass of resin (A).

[0130] <Solvent (C)> Examples of solvent (C) include carboxylic acids having a hydroxyl group, linear or cyclic alkyl ketones, cyclic lactones, alkylene glycol alkyl ethers, alkylene glycol monoalkyl ether carboxylic acid esters (monocarboxylic acid esters of alkylene glycol monoalkyl ethers, and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers). These solvents (C) can be used alone or in combination of two or more.

[0131] Examples of carboxylic acids having a hydroxyl group include ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, ethyl hydroxyethyl acetate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxypropionate, and methyl 2-hydroxy-3-methylbutyrate.

[0132] An example of a cyclic lactone is γ-butyrolactone.

[0133] Examples of alkylene glycol alkyl ethers include alkylene glycol monoalkyl ethers and alkylene glycol dialkyl ethers. Examples of alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), methyl isobutylcarbinol, and propylene glycol monobutyl ether. Examples of alkylene glycol dialkyl ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, and propylene glycol dibutyl ether.

[0134] Examples of alkylene glycol monoalkyl ether carboxylic acid esters include monocarboxylic acid esters of alkylene glycol monoalkyl ethers and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers. Examples of monocarboxylic acid esters of alkylene glycol monoalkyl ethers include alkylene glycol monoalkyl ether acetates. Examples of alkylene glycol monoalkyl ether acetates include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate (1-methoxy-2-propanol monoacetate), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, and ethylene glycol monobutyl ether acetate. Examples of alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers include 2-methoxyethyl methyl carbonate, 2-ethoxyethyl methyl carbonate, 2-ethoxyethyl ethyl carbonate, and 2-propoxyethyl methyl carbonate.

[0135] The solvent (C) content in the resist underlayer film forming composition is not particularly limited, but is preferably 50% to 99.99% by mass, more preferably 75% to 99.95% by mass, and particularly preferably 90% to 99.9% by mass.

[0136] <Crosslinking agent (D)> There are no particular restrictions on the crosslinking agent (D). The crosslinking agent (D) has a structure different from that of the polymer.

[0137] As the crosslinking agent (D), aminoplast crosslinking agents and phenoplast crosslinking agents are preferred. Aminoplast crosslinking agents are addition condensates of a compound having an amino group, such as melamine or guanamine, and formaldehyde. Phenoplast crosslinking agents are addition condensates of a compound having a phenolic hydroxyl group and formaldehyde.

[0138] Examples of crosslinking agents (D) 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, for example, attached to a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0139] R １０１ Preferably, the group is 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 bonding bond.

[0140] Preferred crosslinking agents (D) include melamine compounds, guanamine compounds, glycoluryl compounds, urea compounds, and compounds having a phenolic hydroxyl group. These can be used individually or in combination of two or more.

[0141] Examples of melamine compounds include hexamethylmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 methylol groups of hexamethylmelamine are methoxymethylated or mixtures thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds in which 1 to 6 methylol groups of hexamethylmelamine are acyloxymethylated or mixtures thereof.

[0142] Examples of guanamine compounds include tetramethylolguanamine, tetramethoxymethylguanamine, compounds in which one to four methylol groups of tetramethylolguanamine are methoxymethylated or mixtures thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated or mixtures thereof.

[0143] Examples of glycoluryl compounds include tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are methoxymethylated or mixtures thereof, and compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated or mixtures thereof.

[0144] Furthermore, the glycoluryl compound may also be, for example, a glycoluryl derivative represented by the following formula (1E). (In equation (1E), four R １ Each of these independently represents either a methyl group or an ethyl group, R ２ and R ３ Each of these independently represents a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, or a phenyl group.

[0145] Examples of glycoluryl derivatives represented by formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0146] A glycoluryl derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluryl derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0147] (In formula (2E), R ２ and R ３ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, R ４ Each of these independently represents an alkyl group having 1 to 4 carbon atoms.

[0148] (In formula (3d), R １ (This represents a methyl group or an ethyl group.)

[0149] Examples of glycoluryl derivatives represented by formula (2E) include the compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include the compounds represented by formulas (3d-1) and (3d-2) below.

[0150] Examples of urea compounds include tetramethylolurea, tetramethoxymethylurea, compounds in which one to four methylol groups of tetramethylolurea are methoxymethylated or mixtures thereof, and tetramethoxyethylurea.

[0151] Examples of compounds having a phenolic hydroxyl group include compounds represented by the following formulas (G-1) or (G-2). (In equations (G-1) and (G-2), Q １ R indicates a single bond or an m1-valent organic group. １ and R ４ Each of these represents an alkyl group having 2 to 10 carbon atoms, or an alkyl group having 2 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms. ２ and R ５ Each represents either a hydrogen atom or a methyl group. ３ and R ６ Each of these represents an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms. １ is 1 ≤ n １ n is an integer ≤ 3. ２ is 2 ≤ n ２ An integer n ≤ 5 ３ is 0 ≤ n ３ n is an integer ≤ 3. ４ is 0 ≤ n ４ integers ≤ 3, 3 ≤ (n １ +n ２ +n ３ +n ４ This shows integers n ≤ 6. ５ is 1 ≤ n ５n is an integer ≤ 3. ６ is 1 ≤ n ６ An integer n ≤ 4 ７ is 0 ≤ n ７ n is an integer ≤ 3. ８ is 0 ≤ n ８ integers ≤ 3, 2 ≤ (n ５ +n ６ +n ７ +n ８ (This represents an integer between 5 and 2. m1 represents an integer between 2 and 10.)

[0152] Furthermore, examples of compounds having a phenolic hydroxyl group include compounds represented by the following formulas (G-3) or (G-4). Compounds represented by formulas (G-1) or (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms. (In equations (G-3) and (G-4), Q ２ R indicates a single bond or an m2 valent organic group. ８ , R ９ , R １１ and R １２ Each represents either a hydrogen atom or a methyl group. ７ and R １０ Each of these 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 n is an integer ≤ 3. １０ is 2 ≤ n １０ An integer n ≤ 5 １１ is 0 ≤ n １１ n is an integer ≤ 3. １２ is 0 ≤ n １２ integers ≤ 3, 3 ≤ (n ９ +n １０ +n １１ +n １２ This shows integers n ≤ 6. １３ is 1 ≤ n １３ n is an integer ≤ 3. １４ is 1 ≤ n １４ An integer n ≤ 4 １５ is 0 ≤ n １５ n is an integer ≤ 3. １６ is 0 ≤ n １６ integers ≤ 3, 2 ≤ (n１３ +n １４ +n １５ +n １６ ) indicates an integer ≤ 5. m² indicates an integer from 2 to 10. ) Q ２ Examples of m2 valent organic groups in this context include m2 valent organic groups having 1 to 15 carbon atoms.

[0153] Examples of compounds represented by formula (G-1) or formula (G-2) include the following compounds.

[0154] Examples of compounds represented by formula (G-3) or formula (G-4) include the following compounds. Me represents a methyl group.

[0155] The above compounds can be obtained as products from Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. Examples of such products include TMOM-BP and HMOM-TPPA, both trade names of Asahi Organic Chemicals Co., Ltd.

[0156] Among these, glycoluryl compounds are preferred, specifically tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are methoxymethylated or mixtures thereof, compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated or mixtures thereof, and tetramethoxymethyl glycoluryl is more preferred.

[0157] The molecular weight of the crosslinking agent (D) is not particularly limited, but it is preferably 1,000 or less.

[0158] The content of the crosslinking agent (D) in the resist underlayer film forming composition is not particularly limited, but is, for example, 1% to 70% by mass relative to the polymer, and preferably 5% to 60% by mass.

[0159] <Curing Catalyst (E)> The curing catalyst (E) included as an optional component in the resist underlayer film formation composition can be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator. Examples of thermal acid generating agents 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 salt of p-phenolsulfonic acid), 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, hydroxybenzoic acid, N-methylmorpholine-p-toluenesulfonic acid, N-methylmorpholine-p-hydroxybenzenesulfonic acid, and N-methylmorpholine-5-sulfosalicylic acid.

[0160] Examples of photoacid generators include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0161] Examples of iodonium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-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 nonafluoron-butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethanesulfonate.

[0162] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0163] Examples of disulfonyl diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0164] Only one type of curing catalyst (E) may be used, or two or more types may be used in combination.

[0165] When a curing catalyst (E) is used, the content of the curing catalyst (E) is, for example, 0.1% to 50% by mass, preferably 1% to 30% by mass, relative to the crosslinking agent (D).

[0166] <Other components> The resist underlayer film forming composition does not produce pinholes or striations, and surfactants can be added to further improve the coatability against surface unevenness.

[0167] Examples of surfactants include linear or branched alkylbenzenesulfonic acids (e.g., dodecylbenzenesulfonic acid), 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, and polyoxyethylene sorbitan monolaurate. Examples include nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters like polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorinated surfactants such as F-Top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., product name), Megafac F171, F173, R-30 (manufactured by DIC Corporation, product name), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., product name), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Inc., product name); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants added is usually 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solid content of the resist underlayer film forming composition. These surfactants may be added individually or in combination of two or more types.

[0168] The solid content of the resist underlayer film forming composition of the present invention, i.e., the component excluding the solvent (C), is, for example, 0.01% to 10% by mass.

[0169] The resist underlayer film formation composition of this embodiment is preferable for use in EUV (extreme ultraviolet) exposure processes because it can form resist patterns with higher sensitivity.

[0170] (Resist Underlayer Film) The resist underlayer of the present invention is a cured product of the resist underlayer film forming composition described above. The resist underlayer film can be manufactured, for example, by coating the resist underlayer film forming composition described above onto a semiconductor substrate and firing it.

[0171] Examples of semiconductor substrates to which the resist underlayer film formation composition is applied include silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0172] When a semiconductor substrate with an inorganic film formed on its surface is used, the inorganic film is 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 polysilicon films, silicon oxide films, silicon nitride films, BPSG (Boro-Phosphoric Acid Glass) films, titanium nitride films, titanium oxide nitride films, tungsten films, gallium nitride films, and gallium arsenide films.

[0173] The resist underlayer film forming composition of the present invention is applied to such a semiconductor substrate by an appropriate coating method such as a spinner or coater. Subsequently, the resist underlayer film is formed by baking using a heating means such as a hot plate. The baking conditions are appropriately selected from a bake temperature of 100°C to 400°C and a bake time of 0.3 minutes to 60 minutes. Preferably, the bake temperature is 120°C to 350°C and the bake time is 0.5 minutes to 30 minutes, and more preferably, the bake temperature is 150°C to 300°C and the bake time is 0.8 minutes to 10 minutes.

[0174] The thickness of the resist underlayer film can 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 These are 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).

[0175] The method for measuring the film thickness of the resist underlayer in this specification is as follows: • Measurement device name: Ellipsometer-type film thickness measuring device RE-3100 (SCREEN Corporation) • SWE (single-wavelength ellipsometer) mode • Arithmetic mean of 8 points (for example, 8 points measured at 1 cm intervals in the wafer X direction)

[0176] (Laminate) The laminate of the present invention comprises a semiconductor substrate and a resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrate described above. The resist underlayer film is disposed on top of the semiconductor substrate, for example.

[0177] (Method for manufacturing semiconductor devices, method for forming patterns) The method for manufacturing semiconductor devices of the present invention includes at least the following steps: - A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition of the present invention; and - A step of forming a metal-containing resist film on the resist underlayer film.

[0178] The pattern formation method of the present invention includes at least the following steps: • A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film formation composition of the present invention; • A step of forming a metal-containing resist film on the resist underlayer film; • A step of irradiating the metal-containing resist film with an electron beam or EUV, then developing the metal-containing resist film to obtain a resist pattern; and • A step of etching the resist underlayer film using the resist pattern as a mask.

[0179] In this embodiment, a metal-containing resist film is formed on the resist underlayer film. The thickness of the metal-containing resist film is, for example, 3,000 nm or less, 2,000 nm or less, 1,800 nm or less, 1,500 nm or less, and 1,000 nm or less. The lower limits are 100 nm, 80 nm, 50 nm, 30 nm, 20 nm, and 10 nm.

[0180] The resist film formed on the resist underlayer by a known method (e.g., coating of a resist composition and firing) is not particularly limited as long as it responds to electron beams (EB) or extreme ultraviolet (EUV) used for irradiation. Both negative-type and positive-type photoresists can be used.

[0181] As the resist composition, a metal-containing resist is preferred. A metal-containing resist is also called a metal oxide resist (MOR), and a typical example is a tin oxide-based resist. As a material for a metal oxide resist, for example, a coating composition containing a metal oxo-hydroxo network having an organic ligand via a metal-carbon bond and / or metal-carboxylate bond is described in Japanese Patent Application Publication No. 2019-113855. An example of a metal-containing resist uses a peroxo ligand as a radiosensitizing stabilizing ligand. Details of peroxo-based metal oxo-hydroxo compounds are described in the patent document described in paragraph

[0011] of Publication No. 2019-532489, for example. Examples of relevant patent documents include U.S. Patent No. 9,176,377B2, U.S. Patent Publication No. 2013 / 0224652A1, U.S. Patent No. 9,310,684B2, U.S. Patent Publication No. 2016 / 0116839A1, and U.S. Patent Publication No. 15 / 291738. Examples of materials for metal oxide resists include the compositions and solutions described below.

[0182] A coating comprising a metal oxo-hydroxo network having organic ligands via metal-carbon bonds and / or metal-carboxylate bonds.

[0183] Inorganic oxo / hydroxo-based compositions.

[0184] A coating solution comprising an organic solvent; a first organometallic composition comprising formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (Here, 0 < z ≤ 2 and 0 < (z + x) ≤ 4), equation R' ｎ SnX ４－ｎ A first organometallic composition represented by (where n = 1 or 2), or a mixture thereof, where R and R' are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand or a combination thereof having a hydrolyzable bond to Sn; and a hydrolyzable metal compound of the formula MX' ｖA coating solution comprising a hydrolyzable metal compound represented by (where M is a metal selected from groups 2 to 16 of the periodic table, v is a number from 2 to 6, and X' is a ligand or combination thereof having a hydrolyzable M-X bond).

[0185] Organic solvent and formula RSnO （３／２－ｘ／２） (OH) ｘ A coating solution comprising a first organometallic compound represented by the formula (wherein 0 < x < 3), wherein the solution contains about 0.0025 M to about 1.5 M of tin, and R is an alkyl group or cycloalkyl group having 3 to 31 carbon atoms, wherein the alkyl group or cycloalkyl group is bonded to tin at a secondary or tertiary carbon atom.

[0186] An aqueous solution of an inorganic pattern-forming precursor comprising a mixture of water, a metal suboxide cation, a polyatomic inorganic anion, and a radiation-sensitive ligand containing a peroxide group.

[0187] Other examples of metal-containing resists include the compositions described in Japanese Patent Publication No. 2011-253185, WO2015 / 026482, WO2016 / 065120, WO2017 / 066319, WO2017 / 156388, WO2018 / 031896, Japanese Patent Publication No. 2020-122959, Japanese Patent Publication No. 2020-122960, WO2019 / 099981, WO2019 / 199467, WO2019 / 195522, WO2019 / 195522, WO2020 / 210660, WO2021 / 011367, and WO2021 / 016229. These contents are incorporated into this specification to the same extent as if they were all explicitly stated.

[0188] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and includes a method of applying a coating-type resist material (a composition for forming a metal-containing resist film), which is a metal-containing resist, and firing it.

[0189] Furthermore, the metal-containing resist film may be formed by vapor deposition. An example of a method for forming a metal-containing resist film by vapor deposition is the method described in Japanese Patent Application Publication No. 2017-116923. The contents of Japanese Patent Application Publication No. 2017-116923 are incorporated herein to the same extent as if they were fully disclosed. In Japanese Patent Application Publication No. 2017-116923, the metal-containing resist film in the present invention is referred to as a metal oxide-containing film.

[0190] Irradiation with light or an electron beam is performed, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet) or EB (electron beams) are used. The resist underlayer film forming composition of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, and more preferably for EUV (extreme ultraviolet) exposure. The electron beam irradiation energy and the amount of light exposure are not particularly limited.

[0191] A bake (PEB: Post Exposure Bake) may be performed after irradiation with light or electron beam and before development. The bake 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 bake 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.

[0192] For development, for example, alkaline developers and organic solvents are used. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. As alkaline developers, aqueous solutions of the following alkalis can be used: inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. Furthermore, appropriate amounts of alcohols such as isopropyl alcohol and nonionic surfactants can be added to the aqueous solutions of the above alkalis. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, and more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants can also be added to these developers. Alternatively, instead of using an alkaline developer, development can be performed with an organic solvent such as butyl acetate, and the areas of the photoresist where the alkaline dissolution rate has not improved can be developed.

[0193] Organic solvents can be used as the developer for metal-containing resists, and development is performed with the developer (solvent) after irradiation with light or electron beam. As a result, for example, when a negative-type metal-containing resist film is used, the unexposed areas of the metal-containing resist film are removed, and a pattern of the metal-containing resist film is formed. Examples of developers (organic solvents) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyethyl acetate, ethoxyethyl acetate, 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 - 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 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 may be added to these developers.

[0194] 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. After that, the semiconductor substrate is processed by a known method (such as dry etching) to manufacture a semiconductor device.

[0195] The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

[0196] The weight-average molecular weight of the resin shown in Synthesis Example 3 below was measured by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC instrument manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions were as follows: GPC column: TSKgel Super-MultiporeHZ-N (2 columns) Column temperature: 40°C Solvent: Tetrahydrofuran (THF) Flow rate: 0.35 ml / min Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0197] <Synthesis Example 1> 1.19 g of sodium tetrakis(4-fluorophenyl)borate hydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 8.43 g of ultrapure water. Then, 0.51 g of 35% hydrochloric acid (manufactured by Kanto Chemical Co., Ltd.) was added, followed by 0.30 g of tetramethylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd.), and an ion exchange reaction was carried out for 2 hours. Subsequently, the precipitated white powder was filtered off and washed with water. After that, it was dried for 24 hours (60°C) to obtain 0.97 g of white powder represented by the following structural formula. Furthermore, as a result of 1H-NMR analysis, the content ratio of the anionic part (1) and the cation part (2) was 1:1 in molar ratio.

[0198]

[0199] <Synthesis Example 2> 0.98 g of sodium tetrakis(4-fluorophenyl)borate hydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 7.26 g of ultrapure water. Then, 0.42 g of 35% by mass hydrochloric acid (manufactured by Kanto Chemical Co., Ltd.) was added, and 0.30 g of 1,5,7-triazabicyclo[4.4.0]deca-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and an ion exchange reaction was carried out for 2 hours. Subsequently, the precipitated white powder was filtered off and washed with water. After that, it was dried for 24 hours (60°C) to obtain 0.71 g of white powder represented by the following structural formula. Furthermore, as a result of 1H-NMR analysis, the content ratio of the anionic part (1) and the cation part (3) was 1:1 in molar ratio.

[0200]

[0201] <Synthesis Example 3> 8.00 g of polyglycidyl methacrylate (manufactured by Maruzen Petrochemical Co., Ltd.), 1.46 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.36 g of dibutylhydroxytoluene (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.16 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 14 g of propylene glycol monomethyl ether acetate and 20 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 80°C for 24 hours to obtain a resin solution. The resin solution did not become cloudy or otherwise discolored even when cooled to room temperature (25°C), and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. Analysis by GPC revealed that the resin in the obtained solution had a weight-average molecular weight of 10660 on a standard polystyrene basis. The resin obtained in this synthesis example has structural units represented by the following formula.

[0202]

[0203] <Preparation of Resist Underlayer Film> (Examples 1-4, Comparative Example 1) The compounds or resins obtained in Synthesis Examples 1-3 above, along with the following crosslinking agents, curing catalysts, and solvents, were mixed in the proportions shown in Table 1 and filtered through a 0.1 μm fluororesin filter to prepare compositions for forming resist underlayer films. The abbreviations in Table 1 are as follows. PGME-PL: Imidazo[4,5-d]imidazole-2,5(1H,3H)-dione,tetrahydro-1,3,4,6-tetrakis[(2-methoxy-1-methylethoxy)methyl]- PyPSA: Pyridinium-p-hydroxybenzenesulfonic acid WPBG-345: Represented by the following structural formula, (Z)-{"Bis(dimethylamino)methylidene"amino}-N-cyclohexyl(cyclohexylamino)methaniminium tetrakis(3-fluorophenyl)borate (product name: WPBG-345, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., photobase generator) • WPBG-027: Represented by the following structural formula, (E)-1-Piperidino-3-(2-hydroxyphenyl)-2-propen-1-one (Product name: WPBG-027, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., photobase generator) • PGMEA: Propylene glycol monomethyl ether acetate • PGME: Propylene glycol monomethyl ether The amount of each additive is shown in parts by mass, and the solvent is shown in composition ratio (mass ratio). A "-" in the table means that the component is not contained.

[0204]

[0205] (Elution Test in Photoresist Solvent) Each of the resist underlayer film formation compositions of Examples 1 to 4 and Comparative Example 1 was coated onto a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a film with a thickness of 10 nm. These resist underlayer films were immersed for 1 minute in a mixed solution of propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate = 70 / 30 (mass ratio), which is the solvent used for photoresists. A film thickness change of 5 Å or less was classified as "good," and a change greater than 5 Å was classified as "poor." The results are shown in Table 2.

[0206]

[0207] (Formation of resist patterns by EUV exposure: Negative organic solvent development) The resist underlayer formation compositions of Examples 1 to 4 and Comparative Example 1 were applied to silicon wafers using a spinner. The silicon wafers were baked on a hot plate at 205°C for 60 seconds to obtain a resist underlayer with a thickness of 10 nm. An EUV resist solution (tin oxide-based resist) was spin-coated onto this, and an EUV resist layer was formed by heating at 100°C for 1 minute. Subsequently, exposure was performed using an ASML EUV exposure apparatus (NXE3400) under the conditions of NA = 0.33 and σ = 0.82 / 0.60 (outer / inner). During exposure, exposure was performed through a mask set so that the line width and the width between lines (space width) of the EUV resist would be 14 nm after development as described below, i.e., a dense line with a line and space (L / S) of 14 nm would be formed. After exposure, post-exposure heating (PEB, 170°C for 1 minute) was performed, followed by cooling to room temperature (25°C) on a cooling plate. Development was then carried out using an organic solvent for 60 seconds, followed by hard baking (HB, 250°C for 1 minute) to form a resist pattern. Using a length-measuring SEM (Scanning Electron Microscope, CG4100) manufactured by Hitachi High-Technologies Corporation, the exposure amount (irradiation energy (mJ / cm)) at which a line dimension of 14 nm was formed was measured. ２ The sensitivity was determined by measuring the irradiation energy. Lower irradiation energy indicates higher sensitivity. Table 3 shows the results of measuring the feasibility of line-and-space (LS) pattern formation and the irradiation energy.

[0208]

[0209] Table 3 shows that when a resist underlayer was formed using the resist underlayer formation compositions of Examples 1 to 4, a reduction in optimal irradiation energy was observed compared to when a resist underlayer was formed using the resist underlayer formation composition of Comparative Example 1. This indicates that the resist underlayer formation compositions of Examples 1 to 4 can form resist patterns with high sensitivity.

Claims

1. A composition for forming a resist underlayer film, which is formed between a metal-containing resist film and a substrate, comprising a resin (A), a photobase generator (B), and a solvent (C).

2. The resist underlayer film forming composition according to claim 1, wherein the resin (A) is at least one selected from the group consisting of poly(meth)acrylic resin, polyester resin, polyether resin, polyvinyl resin, resin having an isocyanuric acid structure, resin having a barbituric acid structure, and resin having a hydantoin structure.

3. The resist underlayer film forming composition according to claim 1, wherein the photobase generator (B) is an ionic photobase generator.

4. The resist underlayer film forming composition according to claim 1, wherein the photobase generator (B) is a nonionic photobase generator.

5. The resist underlayer film forming composition according to claim 1, wherein the solvent (C) comprises at least one selected from the group consisting of a carboxylic acid having a hydroxyl group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol monoalkyl ether, a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether.

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

7. The resist underlayer film forming composition according to claim 6, wherein the crosslinking agent (D) is at least one selected from the group consisting of aminoplast crosslinking agents and phenoplast crosslinking agents.

8. The resist underlayer film forming composition according to claim 1, further comprising a curing catalyst (E).

9. The resist underlayer film forming composition according to claim 8, wherein the curing catalyst (E) is a thermal acid generator.

10. The resist underlayer film formation composition according to claim 1, used in an EUV (extreme ultraviolet) exposure process.

11. A resist underlayer film, which is a cured product of a resist underlayer film forming composition according to any one of claims 1 to 10.

12. A laminate comprising a semiconductor substrate and a resist underlayer film according to claim 11.

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

14. A pattern formation method comprising: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of claims 1 to 10; forming a metal-containing resist film on the resist underlayer film; irradiating the metal-containing resist film with an electron beam or EUV, then developing the metal-containing resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

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