Semiconductor substrate manufacturing method and film-forming composition

Abstract

The present invention provides: a semiconductor substrate manufacturing method using a film-forming composition which has good storage stability and can form a film that is excellent in terms of film formation properties, etching resistance and basic liquid resistance; and a film-forming composition. This semiconductor substrate manufacturing method includes a step for coating a substrate with a film-forming composition. The film-forming composition contains a solvent and a metal compound which is composed of at least a metal atom and a polyhydric alcohol, the metal atom being at least one metal that is selected from the group consisting of magnesium, calcium, strontium, barium, scandium, yttrium, zirconium, hafnium, manganese, cobalt, nickel, zinc, aluminum, gallium, indium, tin, and lead.

Description

Semiconductor substrate manufacturing method and film-forming composition

[0001] The present invention relates to a method for producing a semiconductor substrate and a film-forming composition.

[0002] In the manufacture of semiconductor devices, for example, a multilayer resist process is used in which a resist pattern is formed by exposing and developing a resist film laminated on a substrate via a resist underlayer film such as an organic underlayer film or a silicon-containing film. In this process, the resist underlayer film is etched using the resist pattern as a mask, and the substrate is further etched using the resulting resist underlayer film pattern as a mask, thereby forming a desired pattern on the substrate and obtaining a patterned substrate (see JP 2004-177668 A).

[0003] In recent years, metal hard mask compositions have been proposed as resist underlayer films (see Japanese Patent No. 5830048).

[0004] JP 2004-177668 A Japanese Patent No. 5830048 A

[0005] When a silicon-containing film is formed adjacent to a metal hard mask, a basic solution may be used for reprocessing or removing the silicon-containing film. Therefore, a metal hard mask composition is required to be able to form a metal hard mask that has good storage stability, film-forming properties, etching resistance, and basic solution resistance.

[0006] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a method for manufacturing a semiconductor substrate and a film-forming composition that utilizes a film-forming composition that has good storage stability and is capable of forming a film that is excellent in film-forming properties, etching resistance, and basic solution resistance.

[0007] In one embodiment, the present invention relates to a method for producing a semiconductor substrate, comprising: applying a film-forming composition to a substrate; wherein the film-forming composition contains a metal compound (hereinafter also referred to as "compound [A]") composed of at least a metal atom and a polyhydric alcohol; and a solvent (hereinafter also referred to as "solvent [B]"), and the metal atom is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, yttrium, zirconium, hafnium, manganese, cobalt, nickel, zinc, aluminum, gallium, indium, tin, and lead.

[0008] In another embodiment, the present invention relates to a film-forming composition comprising: a metal compound constituted by at least a metal atom and a polyhydric alcohol; and a solvent, wherein the metal atom is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, yttrium, zirconium, hafnium, manganese, cobalt, nickel, zinc, aluminum, gallium, indium, tin, and lead.

[0009] According to the semiconductor substrate manufacturing method, a film-forming composition that has good storage stability and can form a film that is excellent in film-forming properties, etching resistance, and basic solution resistance is used, so that semiconductor substrates can be obtained with a high yield. The film-forming composition can form a film that is excellent in film-forming properties, etching resistance, embedding properties, and basic solution resistance. Therefore, these compositions can be suitably used in the manufacture of semiconductor devices, which are expected to become even more miniaturized in the future.

[0010] 1A and 1B are SEM images of a cross section of a membrane of Example 1-1 and Comparative Example 1-2.

[0011] <<Method for Producing Semiconductor Substrate>> The method for producing a semiconductor substrate includes a step of applying a film-forming composition to a substrate (hereinafter also referred to as a “coating step”). Preferably, the method for producing a semiconductor substrate further includes a step of directly or indirectly forming a resist pattern on the resist underlayer film formed in the coating step (hereinafter also referred to as a “resist pattern forming step”), and a step of forming a pattern on the film by etching using the resist pattern as a mask (hereinafter also referred to as an “etching step”).

[0012] The method for producing a semiconductor substrate may further include, as necessary, a step of forming an organic underlayer film directly or indirectly on the substrate having the resist underlayer film formed in the coating step (hereinafter also referred to as an "organic underlayer film forming step") prior to the resist pattern forming step.

[0013] The method for producing a semiconductor substrate may further include, as necessary, a step of forming a silicon-containing film directly or indirectly on the substrate having the resist underlayer film formed in the coating step (hereinafter also referred to as a "silicon-containing film forming step") prior to the resist pattern forming step.

[0014] First, the film-forming composition used in the method for manufacturing a semiconductor substrate will be described, followed by a description of the steps in the case where the method includes a resist pattern forming step and an etching step, which are preferred steps, and an organic underlayer film forming step and a silicon-containing film forming step, which are optional steps.

[0015] <Film-forming composition> The composition contains the compound (A) and the solvent (B). The composition may contain other optional components as long as the effects of the present invention are not impaired.

[0016] [Compound (A)] The compound (A) refers to a compound constituted by at least a metal atom and a polyhydric alcohol.

[0017] The metal atom constituting the compound [A] is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, yttrium, zirconium, hafnium, manganese, cobalt, nickel, zinc, aluminum, gallium, indium, tin, and lead. Among these, the metal atom is preferably at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, zinc, and tin. The valence of the metal atom is preferably divalent to tetravalent depending on the type of the metal atom.

[0018] The compound (A) contains at least a polyhydric alcohol (hereinafter also referred to as "polyhydric alcohol (x)") as a component other than the metal atom.

[0019] The polyhydric alcohol [x] is not particularly limited as long as it is an organic compound containing two or more hydroxy groups. Examples of the polyhydric alcohol [x] include aliphatic polyhydric alcohols and aromatic polyhydric alcohols.

[0020] Examples of the aliphatic polyhydric alcohol include substituted or unsubstituted aliphatic hydrocarbons, or compounds in which two or more hydrogen atoms of a compound having a divalent heteroatom-containing linking group between carbon atoms of the aliphatic hydrocarbon have been substituted with hydroxy groups.

[0021] Examples of the aliphatic hydrocarbon include chain hydrocarbons having 1 to 20 carbon atoms, alicyclic hydrocarbons having 3 to 20 carbon atoms, and combinations thereof.

[0022] Examples of the chain hydrocarbons having 1 to 20 carbon atoms include linear or branched alkanes such as methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, n-heptane, 2-methylhexane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, and 2,2,3-trimethylbutane; linear or branched alkenes such as ethene, propene, 1-butene, 2-butene, 2-methylpropene, 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, and 3-methyl-1-butene; and Examples include straight-chain or branched alkynes such as acetylene, propyne, 1-butyne, 2-butyne, 1-pentyne, 2-pentyne, and 3-methyl-1-butyne.

[0023] Examples of the alicyclic hydrocarbon having 3 to 20 carbon atoms include monocyclic cycloalkanes such as cyclopropane, cyclobutane, cyclopentane, and cyclohexane, and polycyclic cycloalkanes such as norbornane; monocyclic cycloalkenes such as cyclopropene, cyclobutene, cyclopentene, and cyclohexene, and polycyclic cycloalkenes such as norbornene.

[0024] Examples of the divalent heteroatom-containing linking group include -O-, -CO-, -CS-, -NH-, -S-, and combinations thereof.

[0025] The aromatic polyhydric alcohols include compounds in which two or more hydrogen atoms of a substituted or unsubstituted aromatic compound have been substituted with hydroxy groups. Examples of the aromatic compounds include aromatic compounds having 3 to 20 carbon atoms.

[0026] Examples of the aromatic compound having 3 to 20 carbon atoms include aromatic hydrocarbons having 6 to 20 carbon atoms, such as benzene, naphthalene, anthracene, phenalene, phenanthrene, pyrene, fluorene, and perylene; and aromatic heterocompounds having 3 to 20 carbon atoms, such as triazole, imidazole, furan, pyrrole, thiophene, phosphole, pyrazole, oxazole, isoxazole, thiazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, and carbazole.

[0027] When the aliphatic hydrocarbon or the aromatic compound has a substituent, examples of the substituent include a halogen atom, a cyano group, a nitro group, an amino group, etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0028] The number of hydroxy groups in the polyhydric alcohol is preferably 2, 3, 4, 5 or 6, more preferably 2, 3 or 4, even more preferably 2 or 3, and particularly preferably 2.

[0029] The polyhydric alcohol is preferably an aliphatic polyhydric alcohol, more preferably an aliphatic polyhydric alcohol having 2 to 10 carbon atoms, still more preferably an aliphatic diol having 2 to 10 carbon atoms, and particularly preferably an aliphatic diol having 2 to 10 carbon atoms in which hydroxy groups are bonded to each of two adjacent carbon atoms.

[0030] Specific examples of the polyhydric alcohol [x] include compounds represented by the following formulas (x-1) to (x-24).

[0031]

[0032] The compound [A] may contain other components as long as the effects of the present invention are not impaired. Examples of the other components other than the polyhydric alcohol [x] include organic acids such as carboxylic acids, sulfonic acids, sulfinic acids, organic phosphinic acids, organic phosphonic acids, phenols, enols, thiols, acid imides, oximes, and sulfonamides, hydroxy acid esters, β-diketones, α,α-dicarboxylic acid esters, and amine compounds.

[0033] The composition may contain one or more types of compound (A).

[0034] The compound [A] may contain one or more polyhydric alcohols [x].

[0035] The lower limit of the weight-average molecular weight of the compound [A] is preferably 500, more preferably 800, and even more preferably 1000. The upper limit of the weight-average molecular weight is preferably 10000, more preferably 8000, and even more preferably 7000. This can improve the storage stability of the film-forming composition, as well as the film-forming properties, etching resistance, and basic solution resistance of the resulting film. The method for measuring the weight-average molecular weight of the compound [A] is as described in the Examples.

[0036] The lower limit of the hydrodynamic diameter of the compound [A] measured by dynamic light scattering is preferably 1 nm, more preferably 1.5 nm, and even more preferably 1.8 nm. The upper limit of the hydrodynamic diameter is preferably 10 nm, more preferably 8 nm, and even more preferably 6 nm. This improves the storage stability of the film-forming composition, as well as the film-forming properties, etching resistance, and basic solution resistance of the resulting film. The method for measuring the hydrodynamic diameter of the compound [A] measured by dynamic light scattering is as described in the Examples.

[0037] The lower limit of the content of the compound [A] relative to all components contained in the composition is preferably 0.1 mass%, more preferably 0.5 mass%, and even more preferably 0.8 mass%, and the upper limit of the content is preferably 15 mass%, more preferably 10 mass%, and even more preferably 6 mass%.

[0038] [Method for synthesizing compound [A]] Compound [A] can be synthesized, for example, by a method of carrying out a hydrolysis condensation reaction using a metal-containing compound (hereinafter also referred to as "metal-containing compound [b]"), a method of carrying out a ligand exchange reaction using a metal-containing compound [b], etc. Here, the "hydrolysis condensation reaction" refers to a reaction in which a hydrolyzable group in the metal-containing compound [b] is hydrolyzed to convert it to -OH, and the two resulting -OH groups undergo dehydration condensation to form -O-.

[0039] (Metal-Containing Compound [b]) The metal-containing compound [b] is a metal compound precursor (b1) having a hydrolyzable group, a hydrolyzate of the metal compound precursor (b1) having a hydrolyzable group, a hydrolysis condensate of the metal compound precursor (b1) having a hydrolyzable group, or a combination thereof. The metal compound precursor (b1) can be used alone or in combination of two or more.

[0040] Examples of the hydrolyzable group include a halogen atom, an alkoxy group, and an acyloxy group.

[0041] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0042] Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, a t-butoxy group, and an n-pentoxy group.

[0043] Examples of the acyloxy group include an acetoxy group, an ethyryloxy group, a propionyloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, an n-hexanecarbonyloxy group, and an n-octanecarbonyloxy group.

[0044] The hydrolyzable group is preferably an alkoxy group or an acyloxy group, more preferably an alkoxy group, still more preferably an alkoxy group having 1 to 5 carbon atoms, and particularly preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, or a t-butoxy group.

[0045] [b] When the metal-containing compound is a hydrolysis condensate of a metal compound precursor (b1), the hydrolysis condensate of the metal compound precursor (b1) may be a hydrolysis condensate of a metal compound precursor (b1) having a hydrolyzable group and a compound containing a metalloid atom, as long as the effects of the present invention are not impaired. That is, the hydrolysis condensate of the metal compound precursor (b1) may contain a metalloid atom within a range that does not impair the effects of the present invention. Examples of the metalloid atom include silicon, boron, germanium, antimony, tellurium, etc. The content of the metalloid atom in the hydrolysis condensate of the metal compound precursor (b1) is usually less than 50 atomic % relative to the total of the metal atoms and metalloid atoms in the hydrolysis condensate. The upper limit of the content of the metalloid atom is preferably 30 atomic %, more preferably 10 atomic %, relative to the total of the metal atoms and metalloid atoms in the hydrolysis condensate.

[0046] Examples of the metal compound precursor (b1) include a compound represented by the following formula (α) (hereinafter also referred to as “compound (m)”).

[0047]

[0048] In the above formula (α), M is a metal atom. L is a ligand. a is an integer of 0 to 4. When a is 2 or more, multiple Ls may be the same or different. Y is a hydrolyzable group selected from a halogen atom, an alkoxy group, and an acyloxy group. b is an integer of 0 to 6. Multiple Ys may be the same or different, provided that a+b is 2 or more, and L is a ligand that does not correspond to Y.

[0049] Examples of the metal atom represented by M include the same metal atoms as those exemplified as the metal atoms constituting the compound (A).

[0050] The ligand represented by L may be a monodentate ligand or a polydentate ligand.

[0051] Examples of the monodentate ligand include a hydroxo ligand, a carboxy ligand, an amide ligand, and ammonia.

[0052] The amide ligand may be, for example, an unsubstituted amide ligand (NH ２ ), methylamide ligand (NHMe), dimethylamide ligand (NMe ２ ), diethylamide ligand (NEt ２ ), ethylmethylamide ligand (NEtMe), dipropylamide ligand (NPr ２ ) etc.

[0053] Examples of the polydentate ligand include hydroxy acid esters, β-diketones, β-ketoesters, β-dicarboxylic acid esters, hydrocarbons having a π bond, diphosphines, and amidinate ligands.

[0054] Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylic acid ester.

[0055] Examples of the β-diketone include 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-ethyl-2,4-pentanedione.

[0056] Examples of the β-ketoester include acetoacetic ester, α-alkyl-substituted acetoacetic ester, β-ketopentanoic ester, benzoylacetic ester, and 1,3-acetonedicarboxylic ester.

[0057] Examples of the β-dicarboxylic acid ester include malonic acid diester, α-alkyl-substituted malonic acid diester, α-cycloalkyl-substituted malonic acid diester, and α-aryl-substituted malonic acid diester.

[0058] Examples of the hydrocarbon having a π bond include: chain olefins such as ethylene and propylene; cyclic olefins such as cyclopentene, cyclohexene and norbornene; chain dienes such as butadiene and isoprene; cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene and norbornadiene; and aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene and indene.

[0059] Examples of the diphosphines include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl, and 1,1′-bis(diphenylphosphino)ferrocene.

[0060] Examples of the amidinate ligand include an acetamidinate ligand, a formamidinate ligand, etc. Examples of the acetamidinate ligand include N,N'-dialkylacetamidinate ligands such as an N,N'-dimethylacetamidinate ligand, an N,N'-diethylacetamidinate ligand, an N,N'-di-n-propylacetamidinate ligand, an N,N'-diisopropylacetamidinate ligand, an N,N'-di-n-butylacetamidinate ligand, and an N,N'-di-t-butylacetamidinate ligand. Examples of the formamidinate ligand include N,N'-dialkylformamidinate ligands such as N,N'-dimethylformamidinate ligand, N,N'-diethylformamidinate ligand, N,N'-di-n-propylformamidinate ligand, N,N'-diisopropylformamidinate ligand, N,N'-di-n-butylformamidinate ligand, and N,N'-di-t-butylformamidinate ligand.

[0061] As the halogen atom, alkoxy group and acyloxy group represented by Y, the groups shown as the hydrolyzable group contained in the metal compound precursor (b1) can be suitably employed.

[0062] As b, an integer of 2 to 4 is preferred.

[0063] [b] The metal-containing compound is preferably a metal alkoxide that has not undergone hydrolysis or hydrolytic condensation, or a metal acyloxide that has not undergone hydrolysis or hydrolytic condensation.

[0064] [b] Examples of the metal-containing compound include tetraethoxytin(IV), tetraethoxytin(IV), tetra-isopropoxytin(IV), tetra-n-propoxytin(IV), tetra-isobutoxytin(IV), tetra-n-butoxytin(IV), tetra-sec-butoxytin(IV), tetra-t-butoxytin(IV), tetrakis(dimethylamido)tin(IV), tetrakis(ethylmethylamido)tin(IV), tetrakis(diethylamido)tin(IV), diethoxymagnesium(II), di-n-propoxytin(IV), Dimethoxymagnesium(II), dimethoxycalcium(II), diethoxycalcium(II), diethoxystrontium(II), di-isopropoxystrontium(II), dimethoxybarium(II), diethoxybarium(II), diethoxyyttrium(III), tris-isopropoxyyttrium(III), diethoxycobalt(II), di-isopropoxycobalt(II), tris(dimethylamido)gallium(III), tris(ethylmethylamido)gallium(III), triethoxygallium(III ), diethoxyzinc(II), di-isopropoxyzinc(II), tris-isopropoxyaluminum(III), bis(N,N'-di-isopropylacetamidinato)nickel(II), bis(N,N'-di-t-butylacetamidinato)nickel(II), bis(2,4-pentanedionato)nickel(II), bis(N,N'-di-isopropylformamidinato)nickel(II), bis(N,N'-di-t-butylacetamidinato)manganese(II), bis(N,N'-di-t-butylformamidinato)manganese Scandium(II), tris(N,N'-di-isopropylformamidinato)scandium(III), tris(N,N'-di-isopropylacetamidinato)scandium(III), triethoxyindium(III), tri-isopropoxyindium(III), diethoxylead(II), di-n-propoxylead(II), tetra-isopropoxyzirconium(IV), tetra-t-butoxyzirconium(IV), tetra-isopropoxyhafnium(IV), tetra-t-butoxyhafnium(IV), and the like.

[0065] Among these, metal alkoxides and metal acyloxides are preferred, metal alkoxides are more preferred, and alkoxides of magnesium, calcium, strontium, barium, zinc or tin are even more preferred.

[0066] The lower limit of the amount of the polyhydric alcohol [x] required for synthesis of the compound [A] (the total amount when multiple polyhydric alcohols [x] are included) is preferably 1 mol, more preferably 2 mols, per mol of the metal-containing compound [b], while the upper limit of the amount of the organic acid used is preferably 5 mols, more preferably 4 mols, per mol of the metal-containing compound [b].

[0067] During the synthesis reaction of the compound [A], in addition to the metal compound precursor (b1) and the polyhydric alcohol [x], a compound capable of becoming a multidentate ligand represented by L in the compound of the above formula (α) or a compound capable of becoming a bridging ligand may be added. Examples of the compound capable of becoming a bridging ligand include compounds having multiple hydroxy groups, isocyanate groups, amino groups, ester groups, and amide groups.

[0068] As a method for carrying out a hydrolysis condensation reaction using the metal-containing compound [b], for example, a method of carrying out a hydrolysis condensation reaction of the metal-containing compound [b] in a solvent containing water can be mentioned. In this case, other compounds having hydrolyzable groups may be added as necessary. The lower limit of the amount of water used in this hydrolysis condensation reaction is preferably 0.2 times by mole, more preferably 1 time by mole, and even more preferably 3 times by mole, relative to the hydrolyzable groups of the metal-containing compound [b] or the like. The upper limit of the amount of water is preferably 20 times by mole, more preferably 15 times by mole, and even more preferably 10 times by mole.

[0069] Examples of methods for carrying out a ligand exchange reaction using the metal-containing compound [b] include a method of mixing the metal-containing compound [b] and the polyhydric alcohol [x]. In this case, the mixing may be carried out in a solvent or without a solvent. In addition, a base such as triethylamine may be added to the mixing as needed. The amount of the base added is, for example, 1 part by mass or more and 200 parts by mass or less per 100 parts by mass of the total amount of the metal-containing compound [b] and the compound [a1] used.

[0070] The solvent used in the synthesis reaction of compound [A] (hereinafter also referred to as "solvent [d]") is not particularly limited, and for example, the same solvents as those exemplified as solvent [B] described later can be used. Among these, alcohol solvents, ketone solvents, ether solvents, ester solvents, and hydrocarbon solvents are preferred, monoalcohol solvents, chain ketone solvents, cyclic ether solvents, acetate monoester solvents, and aliphatic hydrocarbon solvents are more preferred, and monoalcohol solvents having 1 to 4 carbon atoms, methyl ethyl ketone, dihydrofuran, ethyl acetate, and dichloromethane are particularly preferred.

[0071] When the solvent [d] is used in the synthesis reaction of the compound [A], the solvent used may be removed after the reaction, but it may also be used as the solvent [B] for the film-forming composition without being removed after the reaction.

[0072] [Solvent (B)] The solvent (B) is not particularly limited as long as it is a solvent that can dissolve or disperse at least the compound (A) and other optional components, etc. The composition may contain one or more solvents (B).

[0073] The solvent (B) may be an organic solvent, such as an alcohol solvent, a ketone solvent, an ether solvent, an ester solvent, a nitrogen-containing solvent, a sulfur-containing solvent, or a hydrocarbon solvent.

[0074] Examples of alcohol solvents include monoalcohol solvents such as methanol, ethanol, n-propanol, and 4-methyl-2-pentanol, and polyalcohol solvents such as ethylene glycol, 1,2-propylene glycol, triethylene glycol, and tripropylene glycol.

[0075] Examples of the ketone solvent include chain ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and 2-heptanone, and cyclic ketone solvents such as cyclohexanone.

[0076] Examples of ether solvents include chain ether solvents such as n-butyl ether, polyhydric alcohol ether solvents such as cyclic ether solvents such as tetrahydrofuran and 1,4-dioxane, and polyhydric alcohol partial ether solvents such as propylene glycol monoethyl ether, tripropylene glycol monomethyl ether, and tetraethylene glycol monomethyl ether.

[0077] Examples of ester-based solvents include carbonate-based solvents such as diethyl carbonate, acetate monoester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate, lactone-based solvents such as γ-butyrolactone, polyhydric alcohol partial ether carboxylate-based solvents such as diethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate, and lactate-based solvents such as methyl lactate and ethyl lactate.

[0078] Examples of the nitrogen-containing solvent include chain nitrogen-containing solvents such as N,N-dimethylacetamide, and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0079] Examples of sulfur-containing solvents include chain sulfur-containing solvents such as dimethyl sulfone and dimethyl sulfoxide, and cyclic sulfur-containing solvents such as sulfolane.

[0080] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as dichloromethane, chloroform, hexane, and cyclohexane, and aromatic solvents such as benzene, toluene, xylene, and mesitylene.

[0081] The solvent (B) is preferably an ether-based solvent, an ester-based solvent, or a combination thereof, more preferably a polyhydric alcohol partial ether-based solvent, a polyhydric alcohol partial ether carboxylate-based solvent, or a combination thereof, and even more preferably propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, or a combination thereof.

[0082] The lower limit of the content of the solvent [B] relative to the total amount of the compound [A] and the solvent [B] is preferably 50% by mass, more preferably 60% by mass, and more preferably 70% by mass. The upper limit of the content is preferably 99.9% by mass, more preferably 99.5% by mass, and more preferably 99% by mass. By setting the content of the solvent [B] within the above range, the composition can be easily prepared and the coatability can be improved.

[0083] [Other Optional Components] The composition may contain other components in addition to those described above, such as an orthoester, an acid generator, a polymer additive, a polymerization inhibitor, a surfactant, a crosslinking agent, a basic compound, and the like.

[0084] When the composition contains other optional components, the content of the other optional components in the composition can be appropriately determined depending on the type, function, etc. of the other optional components used.

[0085] Orthoesters are esters of orthocarboxylic acids. Orthoesters react with water to give carboxylic acid esters, etc. Examples of orthoesters include orthoformates such as methyl orthoformate, ethyl orthoformate, and propyl orthoformate; orthoacetic acid esters such as methyl orthoacetate, ethyl orthoacetate, and propyl orthoacetate; and orthopropionic acid esters such as methyl orthopropionate, ethyl orthopropionate, and propyl orthopropionate. Of these, orthoformates are preferred, and trimethyl orthoformate is more preferred.

[0086] The acid generator is a compound that generates an acid upon irradiation with radiation and / or heating. The composition may contain one or more acid generators.

[0087] Examples of the acid generator include onium salt compounds and N-sulfonyloxyimide compounds.

[0088] The composition may contain one or more polymer additives, which can improve the coatability to the substrate or the organic underlayer film and the continuity of the film.

[0089] Examples of the polymer additive include (poly)oxyalkylene polymer compounds, fluorine-containing polymer compounds, and non-fluorine-containing polymer compounds.

[0090] Examples of the (poly)oxyalkylene polymer compound include polyoxyalkylenes such as (poly)oxyethylene (poly)oxypropylene adducts; (poly)oxyalkyl ethers such as diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene-2-ethylhexyl ether, and oxyethylene oxypropylene adducts to higher alcohols having 12 to 14 carbon atoms; (poly)oxyalkylene (alkyl)aryl ethers such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether; alkylene oxyalkylene aryl ethers of acetylene alcohols such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, and 3-methyl-1-butyn-3-ol; Examples of suitable acetylene ethers include acetylene ethers obtained by addition polymerization of alkyl esters; (poly)oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, and ethylene glycol distearate; (poly)oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly)oxyalkylene alkyl (aryl) ether sulfate salts such as polyoxypropylene methyl ether sodium sulfate and polyoxyethylene dodecylphenol ether sodium sulfate; (poly)oxyalkylene alkyl phosphates such as (poly)oxyethylene stearyl phosphate; and (poly)oxyalkylene alkyl amines such as polyoxyethylene laurylamine.

[0091] Examples of fluorine-containing polymer compounds include compounds described in JP 2011-89090 A. Examples of fluorine-containing polymer compounds include compounds containing a repeating unit derived from a (meth)acrylate compound having a fluorine atom and a repeating unit derived from a (meth)acrylate compound having two or more (preferably five or more) alkyleneoxy groups (preferably ethyleneoxy groups, propyleneoxy groups).

[0092] Examples of non-fluorine-based polymer compounds include linear or branched alkyl (meth)acrylates such as lauryl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isooctyl (meth)acrylate, isostearyl (meth)acrylate, and isononyl (meth)acrylate; alkoxyethyl (meth)acrylates such as methoxyethyl (meth)acrylate; alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate and 1,3-butylene glycol di(meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; dicyclopentenyloxyethyl (meth)acrylate; and nonylphenoxy polyethylene glycol (-(CH ２ CH ２ O) ｎ -structure, n=1 to 17) (meth)acrylate and other compounds containing one or more repeating units derived from a (meth)acrylate monomer or the like.

[0093] The composition may contain one or more polymerization inhibitors, which may enhance the storage stability of the composition.

[0094] Examples of the polymerization inhibitor include hydroquinone compounds such as 4-methoxyphenol and 2,5-di-t-butylhydroquinone, and nitroso compounds such as N-nitrosophenylhydroxylamine and its aluminum salt.

[0095] The composition may contain one or more surfactants, which can improve the coatability onto a substrate or an organic underlayer film and the continuity of the film.

[0096] Commercially available surfactants include, for example, "Newcol 2320," "Newcol 714-F," "Newcol 723," "Newcol 2307," and "Newcol 2303" (all manufactured by Nippon Nyukazai Co., Ltd.), "Paionin D-1107-S", "Paionin D-1007", "Paionin D-1106-DIR", "New Kalgen TG310", "New Kalgen TG310", "Paionin D-6105-W", "Paionin D-6112", "Paionin D-6512" (all manufactured by Takemoto Oil & Fat Co., Ltd.), "Surfynol 420", "Surfynol 440", "Surfynol 465", "Surfynol 2502" (all manufactured by Nippon Air Products Co., Ltd.), "Megafac F171", "Megafac F172", "Megafac F173", "Megafac F176", "Megafac F177", "Megafac F141", "Megafac F142", "Megafac F143", "Megafac F1 Examples of such surfactants include "44", "R30", "F437", "F475", "F479", "F482", "F562", "F563", "F780", "R-40", "DS-21", "RS-56", "RS-90", and "RS-72-K" (all manufactured by DIC Corporation), "Fluorard FC430" and "Fluorard FC431" (all manufactured by Sumitomo 3M Limited), "Asahiguard AG710", "Surflon S-382", "SC-101", "SC-102", "SC-103", "SC-104", "SC-105", and "SC-106" (all manufactured by AGC Inc.), "FTX-218", and "NBX-15" (manufactured by Neos Corporation).

[0097] The type of crosslinking agent is not particularly limited, and known crosslinking agents can be freely selected and used. Preferably, at least one selected from the group consisting of polyfunctional (meth)acrylates, cyclic ether-containing compounds, glycolurils, diisocyanates, melamines, benzoguanamines, polyfunctional thiol compounds, polysulfide compounds, and sulfide compounds is used as the crosslinking agent. When the composition contains a crosslinking agent, the etching resistance of the resist underlayer film can be improved.

[0098] The basic compound accelerates the curing reaction of the composition, thereby improving the strength of the formed film. Examples of basic compounds include compounds having a basic amino group, and base generators that generate compounds having a basic amino group under the action of acid or heat. Examples of compounds having a basic amino group include amine compounds. Examples of base generators include amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds. Specific examples of amine compounds, amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds include the compounds described in paragraphs

[0079] to

[0082] of JP 2016-27370 A.

[0099] [Method for preparing a film-forming composition] The film-forming composition can be prepared by mixing the compound [A], the solvent [B], and, if necessary, any optional components in a predetermined ratio, and preferably filtering the resulting mixture through a membrane filter or the like having a pore size of 0.5 μm or less. In the composition, the compound [A] is preferably dissolved in the solvent [B].

[0100] [Coating Step] In the coating step, the film-forming composition is coated onto a substrate. The coating method for the film-forming composition is not particularly limited, and can be performed by any appropriate method, such as spin coating, casting coating, or roll coating. This forms a coated film, and the solvent (B) volatilizes, forming a film (metal hard mask) as a resist underlayer film.

[0101] Examples of the substrate include metal or semimetal substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, among which silicon substrates are preferred.The substrate may also be a substrate on which a silicon nitride film, an alumina film, a silicon dioxide film, a tantalum nitride film, a titanium nitride film, or the like is formed.

[0102] The substrate may have a pattern. Examples of the shape of the pattern include a trench pattern, a line-and-space pattern, a hole pattern, and a pillar pattern. Examples of the trench pattern and the line-and-space pattern include a pattern including a recess having a width of 5 nm to 100 nm, and a pattern including a recess having a depth of 5 nm to 500 nm. Examples of the hole pattern include a pattern including a hole having a diameter of 5 nm to 100 nm, and a pattern including a hole having a depth of 5 nm to 500 nm. Examples of the pillar pattern include a pattern including a pillar having a width of 5 nm to 100 nm, and a pattern including a pillar having a height of 5 nm to 500 nm.

[0103] The lower limit of the average thickness of the resist underlayer film formed is preferably 3 nm, more preferably 5 nm, and even more preferably 10 nm. The upper limit of the average thickness is preferably 500 nm, more preferably 200 nm, and even more preferably 100 nm. The average thickness is measured according to the method described in the Examples.

[0104] The method for producing a semiconductor substrate preferably further includes a step of heating the coating film formed in the coating step (hereinafter also referred to as a "heating step"). Heating the coating film promotes the formation of a resist underlayer film. More specifically, heating the coating film promotes the volatilization of the solvent (B).

[0105] The coating film is usually heated in air, but may be heated in a nitrogen atmosphere. The lower limit of the heating temperature is preferably 320°C, more preferably 350°C, and even more preferably 380°C. The upper limit of the temperature is preferably 600°C, more preferably 550°C, and even more preferably 500°C. The lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and more preferably 600 seconds.

[0106] [Organic Underlayer Film Forming Step] In this step, prior to the resist pattern forming step, an organic underlayer film is formed directly or indirectly on the substrate having the resist underlayer film formed in the coating step.

[0107] An example of a case where an organic underlayer film is indirectly formed on a substrate having the resist underlayer film is a case where an organic underlayer film is formed on a surface modified film of the resist underlayer film formed on the resist underlayer film.

[0108] The organic underlayer film can be formed by coating an organic underlayer film-forming composition, etc. Examples of methods for forming an organic underlayer film by coating an organic underlayer film-forming composition include a method in which the organic underlayer film-forming composition is directly or indirectly applied to a substrate having the resist underlayer film, and the resulting coating film is heated or exposed to light to cure it. Examples of the organic underlayer film-forming composition that can be used include "HM8006" manufactured by JSR Corporation. The heating and exposure conditions can be appropriately determined depending on the type of organic underlayer film-forming composition used, etc.

[0109] [Silicon-containing film forming step] In this step, prior to the resist pattern forming step, a silicon-containing film is formed directly or indirectly on the substrate having the resist underlayer film formed in the coating step.

[0110] Examples of cases in which a silicon-containing film is indirectly formed on a substrate having the resist underlayer film include cases in which a surface-modified film of the resist underlayer film or the organic underlayer film is formed on the resist underlayer film.

[0111] The silicon-containing film can be formed by coating a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like. Examples of methods for forming a silicon-containing film by coating a silicon-containing film-forming composition include a method in which the silicon-containing film-forming composition is directly or indirectly applied to the resist underlayer film, and the resulting coating film is then cured by exposure and / or heating. Examples of commercially available silicon-containing film-forming compositions include "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all manufactured by JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxynitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0112] [Resist Pattern Forming Step] In this step, a resist pattern is formed directly or indirectly on the resist underlayer film. Methods for performing this step include, for example, a method using a resist composition, a method using a nanoimprinting method, a method using a self-assembling composition, etc. Examples of the case where a resist pattern is indirectly formed on the resist underlayer film include, for example, a case where a resist pattern is formed on the silicon-containing film when the semiconductor substrate manufacturing method includes the silicon-containing film forming step.

[0113] Specifically, in the method using the resist composition, the resist composition is applied so that the resist film to be formed has a predetermined thickness, and then the applied film is pre-baked to volatilize the solvent in the applied film, thereby forming a resist film.

[0114] Examples of the resist composition include positive or negative chemically amplified resist compositions containing a radiation-sensitive acid generator, positive resist compositions containing an alkali-soluble resin and a quinone diazide-based photosensitizer, negative resist compositions containing an alkali-soluble resin and a crosslinker, metal-containing resist compositions containing a metal such as tin, zirconium, or hafnium, etc. In this step, commercially available resist compositions can also be used as they are.

[0115] Next, the resist film formed as above is exposed by selective irradiation with radiation. The radiation used for exposure can be appropriately selected depending on the type of radiation-sensitive acid generator used in the resist composition, and examples thereof include visible light, ultraviolet light, far ultraviolet light, electromagnetic waves such as X-rays and gamma rays, electron beams, molecular beams, particle beams such as ion beams, etc. Among these, far ultraviolet light is preferred, and KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F ２ Excimer laser light (wavelength 157 nm), Kr ２ Excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm) or extreme ultraviolet light (wavelength 13.5 nm or the like, hereinafter also referred to as "EUV") is more preferred, and KrF excimer laser light, ArF excimer laser light or EUV is even more preferred.

[0116] After the exposure, post-baking can be carried out to improve resolution, pattern profile, developability, etc. The temperature and time of this post-baking can be appropriately determined depending on the type of resist composition used, etc.

[0117] Next, the exposed resist film is developed with a developer to form a resist pattern. This development may be alkaline development or organic solvent development. In the case of alkaline development, examples of the developer include basic aqueous solutions of ammonia, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, etc. These basic aqueous solutions may also contain an appropriate amount of a water-soluble organic solvent, such as an alcohol, e.g., methanol or ethanol, a surfactant, etc. In the case of organic solvent development, examples of the developer include the various organic solvents exemplified as the solvent [B] of the composition described above.

[0118] After development with the developer, the resist is washed and dried to form a desired resist pattern.

[0119] [Etching Step] In this step, a pattern is formed on the resist underlayer film by etching using the resist pattern as a mask. The etching may be performed once or multiple times, i.e., sequentially using the pattern obtained by etching as a mask. However, from the viewpoint of obtaining a pattern with a better shape, multiple times is preferred. When performing multiple etchings, etching is performed sequentially in the order of the silicon-containing film, the organic underlayer film, the resist underlayer film, and the substrate. Examples of etching methods include dry etching and wet etching. Among these, dry etching is preferred from the viewpoint of obtaining a better pattern shape on the substrate. For example, a gas plasma such as oxygen plasma is used for this dry etching. A semiconductor substrate having a predetermined pattern is obtained by the above etching.

[0120] Dry etching can be performed using, for example, a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the mask pattern, the elemental composition of the film to be etched, etc., and for example, CHF ３ , C.F. ４ , C ２ F ６ , C ３ F ８ , S.F. ６ Fluorine-based gases such as Cl ２ , BCl ３ Chlorine gases such as O ２ , O ３ , H ２ Oxygen-based gases such as O, H ２ , N.H. ３ , CO, CO ２ , C.H. ４ , C ２ H ２ , C ２ H ４ , C ２ H ６ , C ３ H ４ , C ３ H ６ , C ３ H ８ , HF, HI, HBr, HCl, NO, BCl ３reducing gases such as He, N ２ Inert gases such as Ar and the like can be used. These gases can also be used in combination. When etching a substrate using the pattern of the resist underlayer film as a mask, a fluorine-based gas is usually used.

[0121] The film-forming composition contains a compound [A] and a solvent [B]. As the film-forming composition, the film-forming composition used in the method for manufacturing a semiconductor substrate can be suitably used.

[0122] Examples will be described below. Note that the examples shown below are representative examples of the present invention, and should not be construed as narrowing the scope of the present invention.

[0123] In the present examples, the concentrations of components other than the solvent in the mixture containing the compound (A) and the average thickness of the film were measured by the following methods.

[0124] [Concentration of Components Other Than Solvent in Mixture Containing Compound [A]] 0.5 g of the mixture containing compound [A] was baked at 250°C for 30 minutes, and the mass of the residue was measured. The mass of this residue was divided by the mass of the mixture containing compound [A] to calculate the concentration (mass%) of the components other than the solvent in the mixture containing compound [A].

[0125] [Weight-average molecular weight (Mw)] Measurement was performed by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard, under the following analytical conditions: GPC columns (two "AWM-H," one "AW-H," and two "AW2500" columns, all manufactured by Tosoh Corporation), a flow rate of 0.3 mL / min, an elution solvent of N,N-dimethylacetamide supplemented with LiBr (30 mM) and citric acid (30 mM), and a column temperature of 40°C.

[0126] [Hydrodynamic Diameter by Dynamic Light Scattering] The hydrodynamic diameter was determined by the following procedure: A multi-analyte nanoparticle size measurement system ("nanoSAQLA" manufactured by Otsuka Electronics Co., Ltd.) was used to measure the particle size distribution of the compound [A] diluted in a solvent, and the average diameter was taken as the hydrodynamic diameter.

[0127] [Average Film Thickness] The average film thickness was determined by measuring the film thickness at nine arbitrary positions at 5 cm intervals, including the center of the film formed on the silicon wafer, using a spectroscopic ellipsometer (J.A. WOOLLAM's "M2000D"), and calculating the average value of the film thicknesses.

[0128] <Synthesis of Compound [A]> The [m] compound, [M] compound (for comparison), [x] compound, [X] compound (for comparison), [d] solvent, and [B] solvent used in the synthesis of Compound [A] are shown below. In the following synthesis examples, unless otherwise specified, "parts by mass" refers to a value when the mass of the [m] compound used is taken as 100 parts by mass. Furthermore, "molar ratio" refers to a value when the amount of substance of the [m] compound used is taken as 1. The concentrations (% by mass) of components other than the solvent in mixtures containing Compound [A] are also shown in Table 1.

[0129] The following compounds were used as the compound [m]: m-1: tetra-isopropoxytin(IV) m-2: tetraethoxytin(IV) m-3: tetra-n-propoxytin(IV) m-4: tetra-isobutoxytin(IV) m-5: tetra-n-butoxytin(IV) m-6: tetra-sec-butoxytin(IV) m-7: tetra-t-butoxytin(IV) m-8: tetrakis(dimethylamido)tin(IV) m-9: tetrakis(ethylmethylamido)tin(IV) m-10: tetrakis(diethylamido)tin(IV) m-11: diethoxymagnesium(II) m-12: dimethoxycalcium(II) m-13: diethoxystrontium(II) m-14: dimethoxybarium(II) m-15: Tris-isopropoxy yttrium(III) m-16: Di-isopropoxy cobalt(II) m-17: Tris(dimethylamido) gallium(III) m-18: Diethoxy zinc(II) m-19: Bis(N,N'-di-t-butylacetamidinato) nickel(II) m-20: Bis(N,N'-di-t-butylacetamidinato) manganese(II) m-21: Tris(N,N'-di-isopropylformamidinato) scandium(III) m-22: Tri-isopropoxy indium(III) m-23: Diethoxy lead(II) m-24: Tetra-t-butoxy zirconium(IV) m-25: Tetra-t-butoxy hafnium(IV)

[0130] The following compounds were used as [M] compounds (for comparison): M-1: tetra-isopropoxytitanium(IV) M-2: tetra-n-butoxytitanium(IV)

[0131] As the compound [x], compounds (x-1) to (x-17) represented by the following formulas (x-1) to (x-17) were used.

[0132]

[0133] The following compounds were used as [X] compounds (for comparison): X-1: acrylic acid X-2: acetylacetone

[0134] [d] The following compounds were used as solvents: d-1: isopropanol, d-2: methanol, d-3: ethanol, d-4: 1-propanol, d-5: 1-butanol, d-6: isobutanol, d-7: sec-butanol, d-8: t-butanol, d-9: ethyl acetate, d-10: dichloromethane, d-11: tetrahydrofuran, and d-12: methyl ethyl ketone.

[0135] [B] The following compounds were used as the solvent: B-1: Propylene glycol monomethyl ether B-2: Propylene glycol monomethyl ether acetate B-3: Propylene glycol ethyl ether B-4: Propylene glycol propyl ether

[0136] Synthesis Example 1-1 (Synthesis of [A] Compound (A-1)) Under a nitrogen atmosphere, compound (m-1) (molar ratio 1) and solvent (d-1) (40 parts by mass) were placed in a reaction vessel. Compound (x-1) (molar ratio 2) was then added to the reaction vessel while stirring at 50°C. The reaction was then carried out at 90°C for 3 hours. After completion of the reaction, the reaction vessel was cooled to 30°C or below. The precipitate obtained by cooling was filtered, washed with n-hexane (100 parts by mass), and vacuum dried to obtain compound (A-1). The Mw of compound (A-1) was 2700, and the hydrodynamic diameter was 3.4 nm. The Mw and hydrodynamic diameter of the compounds (A) obtained in the following synthesis examples are also shown in Tables 1-1 to 1-3 below.

[0137] Synthesis Example 1-2 (Synthesis of [A] Compound (A-2)) Under a nitrogen atmosphere, compound (m-1) (molar ratio 1) and solvent (d-1) (40 parts by mass) were charged into a reaction vessel. Compound (x-1) (molar ratio 1) was then added to the reaction vessel while stirring at 50°C. The reaction was then carried out at 90°C for 3 hours. After completion of the reaction, the reaction vessel was cooled to 30°C or below. 900 parts by mass of solvent (B-1) was added to the cooled reaction solution, and then solvent (d-1), the alcohol produced by the reaction, and excess solvent (B-1) were removed using an evaporator to obtain a mixture containing compound (A-2). The concentration of components other than the solvent in the mixture containing compound (A-2) [A] was 20% by mass.

[0138] [Synthesis Examples 1-3 to 1-24, 1-31 to 1-35, 1-43, 1-44, 1-50 to 1-53] (Synthesis of [A] compounds (A-3) to (A-24), (A-31) to (A-35), (A-43), (A-44), and (A-50) to (A-53)) [A] compounds (A-3) to (A-24), (A-31) to (A-35), (A-43), (A-44), and (A-50) to (A-53) were obtained in the same manner as in Synthesis Example 1-2, except that the types and amounts of [m] compound, [x] compound, [d] solvent, and [B] solvent shown in Tables 1-1 to 1-3 below were used.

[0139] Synthesis Example 1-25 (Synthesis of [A] Compound (A-25)) Under a nitrogen atmosphere, compound (m-2) (molar ratio 1) and solvent (d-2) (40 parts by mass) were charged into a reaction vessel. Compound (x-3) (molar ratio 2) was then added to the reaction vessel while stirring at 50°C. The reaction was then carried out at 60°C for 3 hours. After completion of the reaction, the reaction vessel was cooled to 30°C or below. To the cooled reaction solution, 900 parts by mass of solvent (B-1) was added, and then solvent (d-2), the alcohol produced by the reaction, and excess solvent (B-1) were removed using an evaporator to obtain a mixture containing compound (A-25). The concentration of components other than the solvent in the mixture containing compound (A-25) [A] was 20% by mass.

[0140] Synthesis Example 1-26 (Synthesis of [A] Compound (A-26)) Under a nitrogen atmosphere, compound (m-2) (molar ratio 1) and solvent (d-3) (40 parts by mass) were charged into a reaction vessel. Compound (x-3) (molar ratio 2) was then added to the reaction vessel while stirring at 50°C. The reaction was then carried out at 70°C for 3 hours. After completion of the reaction, the reaction vessel was cooled to 30°C or below. To the cooled reaction solution, 900 parts by mass of solvent (B-1) was added, and then solvent (d-3), the alcohol produced by the reaction, and excess solvent (B-1) were removed using an evaporator to obtain a mixture containing compound (A-26). The concentration of components other than the solvent in the mixture containing compound (A-26) was 20% by mass.

[0141] [Synthesis Examples 1-27, 1-30, 1-39, 1-41, 1-45, 1-46, 1-48] (Synthesis of [A] compounds (A-27), (A-30), (A-39), (A-41), (A-45), (A-46), and (A-48)) [A] compounds (A-27), (A-30), (A-39), (A-41), (A-45), (A-46), and (A-48) were obtained in the same manner as in Synthesis Example 1-26, except that the types and amounts of [m] compound, [x] compound, [d] solvent, and [B] solvent shown in Tables 1-2 and 1-3 below were used.

[0142] Synthesis Example 1-28 (Synthesis of [A] Compound (A-28)) Under a nitrogen atmosphere, compound (m-2) (molar ratio 1) and solvent (d-10) (40 parts by mass) were charged into a reaction vessel. Compound (x-3) (molar ratio 2) was then added to the reaction vessel with stirring at 30°C. The reaction was then carried out at 40°C for 3 hours. After completion of the reaction, the reaction vessel was cooled to 30°C or below. To the cooled reaction solution, 900 parts by mass of solvent (B-1) was added, and then the solvent (d-10), the alcohol produced by the reaction, and excess solvent (B-1) were removed using an evaporator to obtain a mixture containing compound (A-28). The concentration of components other than the solvent in the mixture containing compound (A-28) [A] was 20% by mass.

[0143] [Synthesis Examples 1-29, 1-36 to 1-38, 1-40, 1-42, 1-47, 1-49] (Synthesis of [A] Compounds (A-29), (A-36) to (A-38), (A-40), (A-42), (A-47), and (A-49)) [A] Compounds (A-29), (A-36) to (A-38), (A-40), (A-42), (A-47), and (A-49) were obtained in the same manner as in Synthesis Example 1-25, except that the types and amounts of [m] compound, [x] compound, [d] solvent, and [B] solvent shown in Tables 1-2 and 1-3 below were used.

[0144] Comparative Synthesis Examples 1-1 and 1-2 (Synthesis of [A] Compounds (a-1) to (a-2)) [A] Compounds (a-1) to (a-2) were obtained in the same manner as in Synthesis Example 1-2, except that the types and amounts of [M] compound, [X] compound, [d] solvent, and [B] solvent shown in Table 1-3 below were used.

[0145] Comparative Synthesis Example 1-3 (Synthesis of [A] Compound (a-3)) Compound (M-2) (molar ratio 1) and solvent (d-5) (200 parts by mass) were placed in a reaction vessel under a nitrogen atmosphere. Compound (x-13) (molar ratio 4.6) was added to the reaction vessel and stirred at room temperature for 30 minutes. This solution was concentrated under reduced pressure at 50°C, and then further heated to 60°C and continued to be heated under reduced pressure until no more distillate was produced. When no more distillate was observed, 900 parts by mass of solvent (B-2) was added, and the mixture was heated at 50°C under reduced pressure until no more solvent (d-5) was produced, thereby obtaining a mixture containing compound (a-3). The concentration of components other than the solvent in the mixture containing compound (a-3) was 18% by mass.

[0146]

[0147]

[0148]

[0149] <Preparation of Composition> The compounds [A], solvents [B], and other optional components [F] used in the preparation of the composition are shown below.

[0150] The compounds (A-1) to (A-53) synthesized above were used as the compound [A], and the compounds (a-1) to (a-3) synthesized above were used as comparative compounds.

[0151] As the solvent [B], the solvents (B-1) to (B-4) used in the synthesis of the compound [A] were used.

[0152] [F] As other optional components, the following compounds were used: F-1: "NBX-15" manufactured by Neos Co., Ltd. (a compound represented by the following formula (F-1)); F-2: a compound represented by the following formula (F-2); F-3: a surfactant ("DOWSIL SH28 Paint Additive" manufactured by Dow-Toray Industries, Inc.); F-4: trimethyl orthoformate.

[0153]

[0154] [Example 1-1] Preparation of Composition (J-1) As shown in Table 2-1 below, 1 part by mass of [A] compound (A-1) was mixed with 99 parts by mass of [B] solvent (B-1). The resulting solution was filtered through a polytetrafluoroethylene (PTFE) filter with a pore size of 0.2 μm to prepare composition (J-1). In Tables 2-1 and 2-2 below, "-" indicates that the corresponding component was not used. The same applies hereinafter.

[0155] Examples 1-2 to 1-4 Preparation of Compositions (J-2) to (J-4) Compositions (J-2) to (J-4) were prepared in the same manner as in Example 1-1, except that the type and content of each component were as shown in Table 2-1 below.

[0156] [Example 1-5] Preparation of Composition (J-5) As shown in Table 2-1 below, a mixture containing [A] compound (A-2) and (B-1) as a solvent [B] were mixed so that the amount of the solvent [B] was 97 parts by mass (including the solvent [B] contained in the mixture containing the compound [A]) per 3 parts by mass of the components other than the solvent in the compound [A-2]. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) filter with a pore size of 0.2 μm to prepare composition (J-5).

[0157] Examples 1-6 to 1-10, 1-15 to 1-60: Preparation of Compositions (J-6) to (J-10), (J-15) to (J-60) Compositions (J-6) to (J-10), (J-15) to (J-60) were prepared in the same manner as in Example 1-5, except that the type and content of each component were as shown in Tables 2-1 and 2-2 below.

[0158] [Example 1-11] Preparation of composition (J-11) As shown in Table 2-1 below, a mixture containing [A] compound (A-7) and (B-1) as a solvent [B] were mixed so that the amount of the solvent [B] was 97 parts by mass (including the solvent [B] contained in the mixture containing the compound [A]) and the amount of the other optional component [F] (F-1) were 0.005 parts by mass per 3 parts by mass of the components other than the solvent in the compound [A-7]. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) filter with a pore size of 0.2 μm to prepare composition (J-11).

[0159] Examples 1-12 to 1-14 Preparation of Compositions (J-12) to (J-14) Compositions (J-12) to (J-14) were prepared in the same manner as in Example 1-11, except that the type and content of each component were as shown in Table 2-1 below.

[0160] Comparative Examples 1-1 to 1-3: Preparation of Compositions (j-1) to (j-3) Compositions (j-1) to (j-3) were prepared in the same manner as in Example 1-5, except that the type and content of each component were as shown in Table 2-2 below.

[0161]

[0162]

[0163] <Evaluation> In Examples 2-1 to 2-60 and Comparative Examples 2-1 to 2-3, the compositions prepared in the above <Preparation of Composition> and the film-coated substrates obtained in the below <Formation of Film> were evaluated for storage stability, film-forming ability, etching resistance, and basic solution resistance by the following methods. The evaluation results are shown in Tables 3-1 and 3-2 below.

[0164] [Storage Stability] The compositions prepared above were stored at 20±5° C. After 30 days of storage, if no precipitates were observed and the change in Mw compared to the Mw immediately after synthesis was ±500 or less, the composition was evaluated as "A." If no precipitates were observed and the change in Mw compared to the Mw immediately after synthesis was ±800 or less, the composition was evaluated as "B." If precipitates were observed after 30 days of storage, the composition was evaluated as "C."

[0165] <Film formation> The composition prepared above was applied onto a silicon wafer (substrate) by a spin coating method using a spin coater ("LITHIUS Pro Z" manufactured by Tokyo Electron Ltd.) The wafer was then heated at 400°C for 60 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds, thereby obtaining a film-coated substrate on which a film having an average thickness of 90 nm had been formed.

[0166] [Film-forming properties] The cross-sectional shape of the film on the film-coated substrate was observed (100,000 times) using a scanning electron microscope ("S-4800" manufactured by Hitachi High-Technologies Corporation) to obtain SEM images, and the presence or absence of abnormalities was evaluated. Figure 1 shows an SEM image of the cross section of the film of Example 1-1, and Figure 2 shows an SEM image of the cross section of the film of Comparative Example 1-2. The film-forming properties were evaluated as "A" (good) when there were no irregularities in the film or exposed substrate in the SEM image of the cross section, and as "B" (poor) when there were irregularities in the film or exposed substrate.

[0167] [Etching Resistance] The film on the film-coated substrate was subjected to CF etching using an etching apparatus ("TACTRAS" manufactured by Tokyo Electron Limited). ４ The etching rate (nm / min) was calculated from the average thickness of the film before and after the treatment under the conditions of: / Ar = 110 / 440 sccm, PRESS. = 30 MT, HF RF (high frequency power for plasma generation) = 500 W, LF RF (high frequency power for bias) = ​​3000 W, DCS = -150 V, RDC (gas center flow ratio) = 50%, and 30 seconds. Next, the etching rate of Comparative Example 2-1 was used as a reference to calculate the ratio to Comparative Example 2-1, which was used as a measure of etching resistance. The etching resistance was evaluated as "A" (good) when the ratio was less than 1.00, and as "B" (poor) when the ratio was 1.00 or more. Note that "-" in the following Table 3-2 indicates that this is the evaluation standard for etching resistance.

[0168] [Basic Liquid Resistance] The above-mentioned film-coated substrate was immersed in a mixed solution (SC1) of alkaline hydrogen peroxide solution (25 mass % ammonia aqueous solution / 30 mass % hydrogen peroxide aqueous solution / water = 1 / 2 / 40 (mass ratio)) at 60 to 65°C for 5 minutes, washed with water, and dried. The average thickness of the film before and after immersion was measured. The average thickness of the film before immersion was defined as T0 and the average thickness of the film after immersion was defined as T1, and the absolute value of the value obtained by (T1 - T0) x 100 / T0 was calculated to obtain the film thickness change rate (%). For wet peeling resistance, a case where the film thickness change rate was less than 5% was evaluated as "A" (good), and a case where it was 5% or more was evaluated as "B" (poor).

[0169]

[0170]

[0171] As can be seen from the results in Tables 3-1 and 3-2, the compositions of the examples and the films formed from the compositions were superior in storage stability, film-forming properties, etching resistance, and basic solution resistance compared to the comparative examples.

[0172] According to the semiconductor substrate manufacturing method of the present invention, a film-forming composition is used that can form a film having good storage stability, film-forming properties, and etching resistance, as well as excellent resistance to basic solutions, and therefore semiconductor substrates can be obtained with a high yield. The film-forming composition can form a film having excellent film-forming properties, etching resistance, embedding properties, and basic solution resistance. Therefore, these compositions can be suitably used in the manufacture of semiconductor devices, which are expected to become even more miniaturized in the future.

Claims

1. A method for manufacturing a semiconductor substrate, comprising: a step of applying a film-forming composition to a substrate; wherein the film-forming composition contains a metal compound constituted of at least a metal atom and a polyhydric alcohol; and a solvent; and the metal atom is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, yttrium, zirconium, hafnium, manganese, cobalt, nickel, zinc, aluminum, gallium, indium, tin, and lead.

2. The method for producing a semiconductor substrate according to claim 1, wherein the weight average molecular weight of the metal compound is 500 or more and 10,000 or less.

3. The method for producing a semiconductor substrate according to claim 1, wherein the hydrodynamic diameter of said metal compound measured by dynamic light scattering is 1 nm or more and 10 nm or less.

4. The method for producing a semiconductor substrate according to claim 1, wherein the metal atom is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, zinc and tin.

5. The method for manufacturing a semiconductor substrate according to claim 1, wherein the polyhydric alcohol is an aliphatic polyhydric alcohol having 2 to 10 carbon atoms.

6. The method for producing a semiconductor substrate according to claim 1, wherein the polyhydric alcohol is an aliphatic diol having 2 to 10 carbon atoms.

7. The method for producing a semiconductor substrate according to claim 1, wherein the polyhydric alcohol is an aliphatic diol having 2 to 10 carbon atoms in which a hydroxy group is bonded to each of two adjacent carbon atoms.

8. A film-forming composition comprising: a metal compound composed of at least a metal atom and a polyhydric alcohol; and a solvent, wherein the metal atom is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, yttrium, zirconium, hafnium, manganese, cobalt, nickel, zinc, aluminum, gallium, indium, tin, and lead.

9. The film-forming composition according to claim 8, wherein the weight-average molecular weight of the metal compound is 500 or more and 10,000 or less.

10. The film-forming composition according to claim 8, wherein the hydrodynamic diameter of the metal compound measured by dynamic light scattering is 1 nm or more and 10 nm or less.

11. The film-forming composition according to claim 8, wherein the metal atom is at least one selected from the group consisting of magnesium, calcium, strontium, barium, scandium, zinc and tin.

12. The film-forming composition according to claim 8, wherein the polyhydric alcohol is an aliphatic polyhydric alcohol having 2 to 10 carbon atoms.

13. The film-forming composition according to claim 8, wherein the polyhydric alcohol is an aliphatic diol having 2 to 10 carbon atoms.

14. The film-forming composition according to claim 8, wherein the polyhydric alcohol is an aliphatic diol having 2 to 10 carbon atoms in which a hydroxy group is bonded to each of two adjacent carbon atoms.

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