Semiconductor substrate production method and film-forming composition
Patent Information
- Application Number
- JP2025541361
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Priority Date
- 2023-08-21
- Filing Date
- 2024-07-30
- Publication Date
- 2025-02-27
Abstract
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 JP 2013-185155 A).
[0004] JP 2004-177668 A JP 2013-185155 A
[0005] Recently, substrates on which patterns such as trenches and holes are formed have been increasingly used, and metal hard mask compositions are required to have not only excellent etching resistance but also the ability to form metal hard masks with good embedding properties that allow the composition to be fully embedded in the substrate patterns. However, conventional metal hard mask compositions have not been able to satisfy these requirements.
[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a method for producing a semiconductor substrate and a film-forming composition that are capable of forming a film that has excellent etching resistance and embeddability.
[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; the film-forming composition containing: a metal compound (hereinafter also referred to as “compound [A]”) composed of at least a metal atom and an organic acid; and a solvent (hereinafter also referred to as “solvent [B]”); and the organic acid is a compound represented by the following formula (1): (In formula (1), R １ represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms (wherein -L １ ) except for the structure corresponding to —COOH and the structure corresponding to X. １ is an aromatic ring structure having 3 to 30 carbon atoms and r+s+t valence. X is a crosslinkable group. L １ is a single bond or a divalent linking group. t is an integer of 0 to 2. When t is 2, two R １ are the same or different. r is an integer of 1 to 4. When r is 2 or more, multiple Xs are the same or different. s is an integer of 1 to 4. When s is 2 or more, multiple Ls are the same or different. １ are the same or different.)
[0008] As used herein, "organic group" means a group containing at least one carbon atom.
[0009] In another embodiment, the present invention relates to a film-forming composition comprising: a metal compound composed of at least a metal atom and an organic acid; and a solvent, wherein the organic acid is a compound represented by the following formula (1): (In formula (1), R １ represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms (wherein -L １ ) except for the structure corresponding to —COOH and the structure corresponding to X. １ is an aromatic ring structure having 3 to 30 carbon atoms and r+s+t valence. X is a crosslinkable group. L １ is a single bond or a divalent linking group. t is an integer of 0 to 2. When t is 2, two R １are the same or different. r is an integer of 1 to 4. When r is 2 or more, multiple Xs are the same or different. s is an integer of 1 to 4. When s is 2 or more, multiple Ls are the same or different. １ are the same or different.)
[0010] According to the method for producing a semiconductor substrate, a resist underlayer film having excellent etching resistance and embedding ability can be formed, thereby obtaining a well-patterned semiconductor substrate. According to the film-forming composition, a film having excellent etching resistance and embedding ability can be formed. Therefore, these compositions can be suitably used in the production of semiconductor devices, which are expected to become even more miniaturized in the future.
[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 film-forming composition (hereinafter also referred to as "composition") contains a compound (A) and a 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 composed of at least a metal atom and an organic acid. Examples of the metal atom constituting the compound [A] include metal atoms of Groups 3 to 16 of the periodic table (excluding silicon atoms). The compound [A] may contain one or more types of metal atoms.
[0017] Examples of Group 3 metal atoms include scandium, yttrium, lanthanum, and cerium. Examples of Group 4 metal atoms include titanium, zirconium, and hafnium. Examples of Group 5 metal atoms include vanadium, niobium, and tantalum. Examples of Group 6 metal atoms include chromium, molybdenum, and tungsten. Examples of Group 7 metal atoms include manganese and rhenium. Examples of Group 8 metal atoms include iron, ruthenium, and osmium. Examples of Group 9 metal atoms include cobalt, rhodium, and iridium. Examples of Group 10 metal atoms include nickel, palladium, and platinum. Examples of Group 11 metal atoms include copper, silver, and gold. Examples of Group 12 metal atoms include zinc, cadmium, and mercury. Examples of Group 13 metal atoms include aluminum, gallium, and indium. Examples of Group 14 metal atoms include germanium, tin, and lead. Examples of metal atoms in Group 15 include antimony and bismuth, and examples of metal atoms in Group 16 include tellurium.
[0018] The metal atoms constituting the compound [A] are preferably metal atoms of Groups 3 to 16, more preferably metal atoms of Groups 4 to 14, even more preferably metal atoms of Groups 4, 5, and 14, and particularly preferably metal atoms of Group 4. Specifically, titanium, zirconium, hafnium, tantalum, tungsten, tin, or a combination thereof is more preferred.
[0019] The compound [A] contains at least an organic acid (hereinafter also referred to as an organic acid [a]) as a component other than the metal atom (hereinafter also referred to as an organic compound [x]). Here, an "organic acid" refers to an organic compound that exhibits acidity, and an "organic compound" refers to a compound having at least one carbon atom.
[0020] The compound [A] includes a compound represented by the following formula (1) (hereinafter also referred to as "compound [a1]") as the organic acid [a].
[0021] (In formula (1), R １ represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms (wherein -L １ ) except for the structure corresponding to —COOH and the structure corresponding to X. １ is an aromatic ring structure having 3 to 30 carbon atoms and r+s+t valence. X is a crosslinkable group. L １ is a single bond or a divalent linking group. t is an integer of 0 to 2. When t is 2, two R １ are the same or different. r is an integer of 1 to 4. When r is 2 or more, multiple Xs are the same or different. s is an integer of 1 to 4. When s is 2 or more, multiple Ls are the same or different. １ are the same or different.)
[0022] R １ Examples of the monovalent organic group having 1 to 20 carbon atoms and represented by the formula (I) include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group having a divalent heteroatom-containing group between carbon atoms of the hydrocarbon group (hereinafter also referred to as "group (α)"), a group in which some or all of the hydrogen atoms of the hydrocarbon group have been substituted with monovalent heteroatom-containing groups (hereinafter also referred to as "group (β)"), a group in which some or all of the hydrogen atoms of the group (α) have been substituted with monovalent heteroatom-containing groups (hereinafter also referred to as "group (γ)"), and combinations thereof.
[0023] However, R １ As the monovalent organic group having 1 to 20 carbon atoms represented by -L in the above formula (1), １ Excluding structures corresponding to —COOH and structures corresponding to X.
[0024] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and groups formed by combining these groups.
[0025] Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group; alkenyl groups such as an ethenyl group, a propenyl group, and a butenyl group; and alkynyl groups such as an ethynyl group, a propynyl group, and a butynyl group.
[0026] Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group; cycloalkenyl groups such as a cyclopropenyl group, a cyclopentenyl group and a cyclohexenyl group; bridged ring saturated hydrocarbon groups such as a norbornyl group, an adamantyl group and a tricyclodecyl group; and bridged ring unsaturated hydrocarbon groups such as a norbornenyl group and a tricyclodecenyl group.
[0027] Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a tolyl group, a naphthyl group, an anthracenyl group, and a pyrenyl group.
[0028] Examples of heteroatoms constituting the divalent or monovalent heteroatom-containing group include oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, and halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.
[0029] Examples of the divalent heteroatom-containing group include -CO-, -CS-, -NR'-, -O-, -S-, and combinations thereof, where R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
[0030] Examples of the monovalent heteroatom-containing group include a hydroxy group, a sulfanyl group, a cyano group, a nitro group, and a halogen atom.
[0031] R １As the alkyl group, a hydroxy group, an alkyl group having 1 to 5 carbon atoms or a halogen atom is preferred, and a hydroxy group, a methyl group or a chlorine atom is more preferred.
[0032] Ar １ Examples of aromatic ring structures having 3 to 30 carbon atoms and a valence of r+s+t include structures obtained by removing r+s+t hydrogen atoms from a structure containing an aromatic ring and having 3 to 30 carbon atoms. The aromatic ring-containing structure of 3 to 30 carbon atoms is not limited to structures containing only an aromatic ring, but also includes structures in which an aromatic ring and an alicyclic ring are combined. Examples of structures in which an aromatic ring and an alicyclic ring are combined include a fused ring in which an aromatic ring and an alicyclic ring share one side (two adjacent atoms), and a ring assembly in which an aromatic ring and an alicyclic ring are bonded by a single bond.
[0033] The aromatic ring is preferably an aromatic ring having 3 to 30 carbon atoms, and examples thereof include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring; aromatic heterocycles such as a furan ring, a pyrrole ring, a thiophene ring, a phosphole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring; and combinations thereof (i.e., fused rings).
[0034] Examples of the alicyclic ring include alicyclic hydrocarbons having 3 to 20 carbon atoms and aliphatic heterocyclic rings having 3 to 20 carbon atoms.
[0035] The alicyclic hydrocarbon having 3 to 20 carbon atoms includes the above-mentioned R １ A structure corresponding to the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms in the above formula (I) can be suitably employed.
[0036] Examples of the aliphatic heterocycle having 3 to 20 carbon atoms include: an oxygen atom-containing aliphatic heterocycle such as oxirane, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane; a nitrogen atom-containing aliphatic heterocycle such as aziridine, pyrrolidine, piperidine, and piperazine; a sulfur atom-containing aliphatic heterocycle such as thietane, thiolane, and thiane; an aliphatic heterocycle containing multiple types of heteroatoms such as morpholine, 1,2-oxathiolane, and 1,3-oxathiolane; or a combination thereof.
[0037] The aromatic ring structure is preferably an aromatic hydrocarbon ring structure having 6 to 14 carbon atoms or an aromatic heterocyclic ring structure having 6 to 10 carbon atoms, more preferably an aromatic hydrocarbon ring structure having 6 to 14 carbon atoms, further preferably a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring, and particularly preferably a benzene ring.
[0038] The crosslinkable group represented by X is a group containing a structure having crosslinkability. The crosslinkable structure is not particularly limited as long as it is a structure that forms a crosslinked structure between molecules by a reaction under heating conditions, active energy ray irradiation conditions, acidic conditions, etc. Examples of the crosslinkable structure include a structure containing a carbon-carbon double bond, a structure containing a carbon-carbon triple bond, a halogen atom, an acid anhydride structure, a carboxy group, an amino group, a cyano group, and a hydroxy group.
[0039] The above X is preferably a group selected from the group consisting of groups represented by any one of the following formulas (2-1) to (2-5): (In formulas (2-1), (2-2), (2-5), R ８ , R ９ , R １０ , R １１ and R １２ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ７ are each independently a divalent linking group or a single bond. １ is the bond to the atoms that make up the atom.)
[0040] R ８ , R ９ , R１０ , R １１ and R １２ The monovalent organic group having 1 to 20 carbon atoms represented by the formula (1) is R １ A monovalent organic group having 1 to 20 carbon atoms and represented by the following formula can be suitably used.
[0041] R ８ , R ９ , R １０ and R １１ is preferably a hydrogen atom. １２ is preferably a hydrogen atom or a methyl group.
[0042] R ７ As the divalent linking group represented by the formula (I), for example, a divalent hydrocarbon group, —COO—, —OCO—, —O—CO—O—, —CONH—, —O—, —S—, —CO—, or a group combining these can be suitably used.
[0043] R ７ The divalent hydrocarbon group in R １ A group in which one hydrogen atom has been removed from a monovalent hydrocarbon group having 1 to 20 carbon atoms can be suitably used.
[0044] R ７ is preferably a divalent chain hydrocarbon group having 1 to 5 carbon atoms, —O—, a combination thereof, or a single bond, and more preferably a methylene group, —O—, a combination of a methylene group and —O—, or a single bond.
[0045] L １ The divalent linking group represented by the above R ７ A divalent linking group represented by the following formula can be preferably used.
[0046] L １ is preferably a divalent chain hydrocarbon group having 1 to 5 carbon atoms or a single bond, and more preferably a methylene group, an ethanediyl group, a propane-2,2-diyl group or a single bond.
[0047] t is preferably 0 or 1. r is preferably an integer of 1 to 3, more preferably 1 or 2. s is preferably an integer of 1 to 3, more preferably 1 or 2.
[0048] Specific examples of the compound [a1] include compounds represented by the following formulas (1-1) to (1-30).
[0049]
[0050]
[0051] Examples of the organic acid [a] other than the compound [a1] include carboxylic acids (excluding the compound [a1]), sulfonic acids, sulfinic acids, organic phosphinic acids, organic phosphonic acids, phenols, enols, thiols, acid imides, oximes, and sulfonamides.
[0052] Examples of the carboxylic acid include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butanoic acid (butyric acid), isobutyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, 2-ethylhexanoic acid, oleic acid, acrylic acid, methacrylic acid, trans-2,3-dimethylacrylic acid, stearic acid, linoleic acid, linolenic acid, arachidonic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, gallic acid, and shikimic acid; and dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, and tartaric acid. Also included are carboxylic acids having three or more carboxy groups, such as citric acid.
[0053] Examples of the sulfonic acid include benzenesulfonic acid and p-toluenesulfonic acid.
[0054] Examples of the sulfinic acid include benzenesulfinic acid and p-toluenesulfinic acid.
[0055] Examples of the organic phosphinic acid include diethylphosphinic acid, methylphenylphosphinic acid, and diphenylphosphinic acid.
[0056] Examples of the organic phosphonic acid include methylphosphonic acid, ethylphosphonic acid, t-butylphosphonic acid, cyclohexylphosphonic acid, and phenylphosphonic acid.
[0057] Examples of the phenols include monohydric phenols such as phenol, cresol, 2,6-xylenol, and naphthol; dihydric phenols such as catechol, resorcinol, hydroquinone, and 1,2-naphthalenediol; and trihydric or higher phenols such as pyrogallol and 2,3,6-naphthalenetriol.
[0058] Examples of the enol include 2-hydroxy-3-methyl-2-butene and 3-hydroxy-4-methyl-3-hexene.
[0059] Examples of the thiol include mercaptoethanol and mercaptopropanol.
[0060] Examples of the acid imide include carboxylic acid imides such as maleimide and succinimide, and sulfonic acid imides such as di(trifluoromethanesulfonic acid)imide and di(pentafluoroethanesulfonic acid)imide.
[0061] Examples of the oxime include aldoximes such as benzaldoxime and salicylaldoxime, and ketoximes such as diethylketoxime, methylethylketoxime and cyclohexanoneoxime.
[0062] Examples of the sulfonamide include methylsulfonamide, ethylsulfonamide, benzenesulfonamide, and toluenesulfonamide.
[0063] Examples of the compound [x] other than the organic acid [a] include hydroxy acid esters, β-diketones, α,α-dicarboxylic acid esters, and amine compounds.
[0064] Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, salicylic acid ester, and the like.
[0065] Examples of the β-diketone include 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-ethyl-2,4-pentanedione.
[0066] Examples of the β-ketoester include acetoacetic ester, α-alkyl-substituted acetoacetic ester, β-ketopentanoic ester, benzoylacetic ester, and 1,3-acetonedicarboxylic ester.
[0067] Examples of the β-ketoester include acetoacetic ester, α-alkyl-substituted acetoacetic ester, β-ketopentanoic ester, benzoylacetic ester, and 1,3-acetonedicarboxylic ester.
[0068] Examples of the amine compound include diethanolamine and triethanolamine.
[0069] The compound [A] is preferably a metal compound constituted by a metal atom of Group 4, Group 5, or Group 14 and the compound [a1], more preferably a metal compound constituted by a metal atom of Group 4 or Group 14 and the compound [a1] having a crosslinkable group represented by formula (2-3) or (2-5), and even more preferably a metal compound constituted by titanium, zirconium, hafnium, tantalum, tungsten, or tin and 4-vinylbenzoic acid or 4-vinylbenzeneacetic acid. The form in which the organic acid [a] is contained in the compound [A] also includes an organic acid anion formed by removing a hydrogen ion from the organic acid [a].
[0070] The compound (A) may contain one or more of the above metal compounds.
[0071] The compound (A) may contain one or more organic acids (a).
[0072] 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 1 mass%, and the upper limit of the content is preferably 15 mass%, more preferably 10 mass%, and even more preferably 5 mass%.
[0073] [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 metal-containing compound [b], etc. Here, the "hydrolysis condensation reaction" refers to a reaction in which a hydrolyzable group in metal-containing compound [b] is hydrolyzed to convert it to -OH, and the two resulting -OH groups undergo dehydration condensation to form -O-.
[0074] (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.
[0075] Examples of the hydrolyzable group include a halogen atom, an alkoxy group, and an acyloxy group.
[0076] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
[0077] Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, and an n-butoxy group.
[0078] 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.
[0079] The hydrolyzable group is preferably an alkoxy group or an acyloxy group, more preferably an isopropoxy group or an acetoxy group.
[0080] [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.
[0081] Examples of the metal compound precursor (b1) include a compound represented by the following formula (α) (hereinafter also referred to as “compound (m)”).
[0082]
[0083] 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 4 or more, and L is a ligand that does not correspond to Y.
[0084] Examples of the metal atom represented by M include the same metal atoms as those exemplified as the metal atoms constituting the compound (A).
[0085] The ligand represented by L may be a monodentate ligand or a polydentate ligand.
[0086] Examples of the monodentate ligand include a hydroxo ligand, a carboxy ligand, an amide ligand, and ammonia.
[0087] The amide ligand may be, for example, an unsubstituted amide ligand (NH ２ ), methylamide ligand (NHMe), dimethylamide ligand (NMe ２ ), diethylamide ligand (NEt ２ ), dipropylamide ligand (NPr ２ ) etc.
[0088] Examples of the polydentate ligand include hydroxy acid esters, β-diketones, β-ketoesters, β-dicarboxylic acid esters, hydrocarbons having a π bond, and diphosphines.
[0089] Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, salicylic acid ester, and the like.
[0090] Examples of the β-diketone include 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-ethyl-2,4-pentanedione.
[0091] Examples of the β-ketoester include acetoacetic ester, α-alkyl-substituted acetoacetic ester, β-ketopentanoic ester, benzoylacetic ester, and 1,3-acetonedicarboxylic ester.
[0092] 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.
[0093] 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.
[0094] 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.
[0095] Examples of the halogen atom represented by Y include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
[0096] Examples of the alkoxy group represented by Y include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
[0097] Examples of the acyloxy group represented by Y include an acetoxy group, an ethyryloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, an n-hexanecarbonyloxy group, and an n-octanecarbonyloxy group.
[0098] Y is preferably an alkoxy group or an acyloxy group, more preferably an isopropoxy group or an acetoxy group.
[0099] As b, 3 and 4 are preferred, and 4 is more preferred.
[0100] [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.
[0101] [b] Examples of metal-containing compounds include zirconium tetra-n-butoxide, zirconium tetra-n-propoxide, zirconium tetraisopropoxide, hafnium tetraethoxide, indium triisopropoxide, hafnium tetraisopropoxide, hafnium tetra-n-propoxide, hafnium tetra-n-butoxide, tantalum pentaethoxide, tantalum penta-n-butoxide, tungsten pentamethoxide, tungsten pentaethoxide, tungsten penta-n-butoxide, tungsten hexaethoxide, tungsten hexa-n-butoxide, iron chloride, zinc diisopropoxide, zinc acetate dihydrate, ortho Tetrabutyl titanate, titanium tetra-n-butoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, zirconium di-n-butoxide bis(2,4-pentanedionate), titanium tri-n-butoxide stearate, bis(cyclopentadienyl)hafnium dichloride, bis(cyclopentadienyl)tungsten dichloride, diacetato[(S)-(-)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium, dichloro[ethylenebis(diphenylphosphine)]cobalt, titanium butoxide oligomer, aminopropyltrimethoxytitanium, aminopropyltriethoxyzirconium, 2-(3,4-epoxycyclohexyl)ethyltrimethoxyzirconium, γ-glycidoxypropyltrimethoxyzirconium, 3-isocyanopropyltrimethoxyzirconium, 3-isocyanopropyltriethoxyzirconium, triethoxymono(acetylacetonate)titanium, tri-n-propoxymono(acetylacetonate)titanium, tri-isopropoxymono(acetylacetonate)titanium, triethoxymono(acetylacetonate)zirconium, tri-n-propoxymono(acetylacetonate)zirconium, tri-isopropoxymono(acetylacetonate)zirconium , diisopropoxybis(acetylacetonate)titanium, di-n-butoxybis(acetylacetonate)titanium, di-n-butoxybis(acetylacetonate)zirconium, tri(3-methacryloxypropyl)methoxyzirconium, tri(3-acryloxypropyl)methoxyzirconium, tin tetramethoxide, tin tetraethoxide, tin tetra-n-propoxide, tin tetraisopropoxide, tin tetra-n-butoxide, tin tetraisobutoxide, tin tetra-s-butoxide, tin tetra-t-butoxide, lanthanum oxide, yttrium oxide, etc.
[0102] Of these, metal alkoxides and metal acyloxides are preferred, metal alkoxides are more preferred, and alkoxides of titanium, zirconium, hafnium, tantalum, tungsten and tin are even more preferred.
[0103] The lower limit of the amount of the compound [a1] used (the total amount when an organic acid [a] other than the compound [a1] is included) required for synthesizing the compound [A] is preferably 1 mol, more preferably 2 mols, per mol of the metal-containing compound [b]. On the other hand, the upper limit of the amount of the organic acid used is preferably 6 mols, more preferably 5 mols, per mol of the metal-containing compound [b].
[0104] During the synthesis reaction of compound [A], in addition to the metal compound precursor (b1) and compound [a1], a compound capable of becoming a multidentate ligand represented by L in the compound of 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.
[0105] 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.
[0106] 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 compound [a1]. In this case, the mixture may be mixed in a solvent or without a solvent. In addition, a base such as triethylamine may be added to the mixture as needed. The amount of the base added is, for example, 1 part by mass or more and 200 parts by mass or less relative to 100 parts by mass of the total amount of the metal-containing compound [b] and the compound [a1] used.
[0107] 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 below can be used. Among these, alcohol-based solvents, ether-based solvents, ester-based solvents, and hydrocarbon-based solvents are preferred, alcohol-based solvents, ether-based solvents, and ester-based solvents are more preferred, monoalcohol-based solvents, polyhydric alcohol partial ether-based solvents, and polyhydric alcohol partial ether carboxylate-based solvents are even more preferred, and monoalcohol-based solvents having 1 to 4 carbon atoms, propylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate are particularly preferred.
[0108] 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.
[0109] [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).
[0110] 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.
[0111] 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.
[0112] 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.
[0113] Examples of the ether solvent 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.
[0114] 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.
[0115] 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.
[0116] 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.
[0117] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and cyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.
[0118] The solvent (B) is preferably an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, or a combination thereof; more preferably a monoalcohol solvent, a polyhydric alcohol partial ether solvent, an acetate monoester solvent, a polyhydric alcohol partial ether carboxylate solvent, a chain ketone solvent, or a combination thereof; and even more preferably 4-methyl-2-pentanol, propylene glycol monomethyl ether, butyl acetate, propylene glycol monomethyl ether acetate, 2-heptanone, or a combination thereof.
[0119] 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.
[0120] [Other Optional Components] The composition may contain other components in addition to those described above, such as an aromatic ring-containing compound having a molecular weight of 300 or more, an acid generator, a polymer additive, a polymerization inhibitor, a surfactant, a crosslinking agent, a basic compound, and the like.
[0121] 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.
[0122] The aromatic ring-containing compound having a molecular weight of 300 or more is not particularly limited as long as it has an aromatic ring and a molecular weight of 300 or more. The aromatic ring-containing compound may be a polymer having two or more structural units (repeating units) containing an aromatic ring, or may be a compound that does not fall under the above-mentioned polymer. Examples of the aromatic ring-containing compound include the compounds described in paragraphs
[0163] to
[0168] of WO 2023 / 021971, the polymers described in paragraphs
[0221] to
[0225] of JP-T-2022-521531, and the polymers described in paragraph
[0067] of JP-T-2023-521230.
[0123] 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.
[0124] Examples of the acid generator include onium salt compounds and N-sulfonyloxyimide compounds.
[0125] The composition may contain one or more polymer additives, which can improve the coatability to a substrate or an organic underlayer film and the continuity of the film.
[0126] Examples of the polymer additive include (poly)oxyalkylene polymer compounds, fluorine-containing polymer compounds, and non-fluorine-containing polymer compounds.
[0127] 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.
[0128] 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).
[0129] 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 Examples of the compound include compounds containing one or more repeating units derived from a (meth)acrylate monomer such as (meth)acrylate having a - structure (n=1 to 17).
[0130] The composition may contain one or more polymerization inhibitors, which may enhance the storage stability of the composition.
[0131] Examples of the polymerization inhibitor include hydroquinone compounds such as 4-methoxyphenol and 2,5-di-tert-butylhydroquinone, and nitroso compounds such as N-nitrosophenylhydroxylamine and its aluminum salt.
[0132] 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.
[0133] 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 suitable fluoride-resistant coatings include "Fluoride 44," "Fluoride R30," "Fluoride F437," "Fluoride F475," "Fluoride F479," "Fluoride F482," "Fluoride F562," "Fluoride F563," "Fluoride F780," "Fluoride R-40," "Fluoride DS-21," "Fluoride RS-56," "Fluoride RS-90," and "Fluoride RS-72-K" (all manufactured by DIC Corporation), "Fluorade FC430" and "Fluorade FC431" (all manufactured by Sumitomo 3M Limited), "Asahiguard AG710," "Surflon S-382," "Surflon SC-101," "Surflon SC-102," "Surflon SC-103," "Surflon SC-104," "Surflon SC-105," and "Surflon SC-106" (all manufactured by AGC Inc.), "FTX-218," and "NBX-15" (manufactured by Neos Corporation).
[0134] The type of crosslinking agent is not particularly limited, and any known crosslinking agent (excluding compounds corresponding to the above-mentioned aromatic ring-containing compounds having a molecular weight of 300 or more) can be freely selected and used. Preferably, at least one selected from 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.
[0135] 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.
[0136] [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].
[0137] [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.
[0138] 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.
[0139] The substrate may have a pattern. Because the film-forming composition has excellent embedding properties, even when the substrate has a pattern, it can form a good film while filling the gaps between the patterns. Examples of the pattern shape include a trench pattern, a line-and-space pattern, a hole pattern, and a pillar pattern. Examples of trench patterns and line-and-space patterns include a pattern including a recess with a width of 5 nm to 100 nm, and a pattern including a recess with a depth of 5 nm to 500 nm. Examples of hole patterns include a pattern including a hole with a diameter of 5 nm to 100 nm, and a pattern including a hole with a depth of 5 nm to 500 nm. Examples of pillar patterns include a pattern including a pillar with a width of 5 nm to 100 nm, and a pattern including a pillar with a height of 5 nm to 500 nm.
[0140] 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.
[0141] 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).
[0142] 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 350°C, more preferably 380°C, and even more preferably 400°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.
[0143] [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.
[0144] 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.
[0145] 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.
[0146] [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.
[0147] 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.
[0148] 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).
[0149] [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.
[0150] 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.
[0151] 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.
[0152] 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.
[0153] 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.
[0154] 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.
[0155] After development with the developer, the resist is washed and dried to form a desired resist pattern.
[0156] [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.
[0157] 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 , SF 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.
[0158] 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.
[0159] 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.
[0160] 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.
[0161] [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].
[0162] [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.
[0163] <Synthesis of Compound [A]> The [m] compound, [x] compound, [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.
[0164] The following compounds were used as compounds [m]. m-1: tetra-n-propoxyzirconium(IV) m-2: tetra-n-butoxyzirconium(IV) m-3: tetra-n-propoxyhafnium(IV) m-4: tetraisopropoxytitanium(IV) m-5: pentaethoxytantalum(V) m-6: tetramethoxytin(IV) m-7: tetraethoxytin(IV) m-8: tetra-n-propoxytin(IV) m-9: tetraisopropoxytin(IV) m-10: tetra-n-butoxytin(IV) m-11: tetraisobutoxytin(IV) m-12: tetra-sec-butoxytin(IV) m-13: tetra-tert-butoxytin(IV) m-14: pentaethoxytungsten(V)
[0165] The following compounds were used as the [x] compounds. x-1: 4-Vinylbenzoic acid x-2: 4-Vinyl-2-hydroxybenzoic acid x-3: 4-(2-methyl-2-propenyl)benzoic acid x-4: 4-(2-propenyl)benzoic acid x-5: 4-Ethenyloxybenzoic acid x-6: 4-Vinylbenzeneacetic acid x-7: 4-Vinyl-α,α-dimethylbenzeneacetic acid x-8: 5-Vinyl-1H-indole-2-carboxylic acid x-9: 6-Vinyl-2-naphthalenecarboxylic acid x-10: 7-Vinyl-1-phenanthrenecarboxylic acid x-11: 4-Ethynylbenzoic acid x-12: 4-Ethynyl-3-methylbenzoic acid x-13: 2-Chloro-4-ethynylbenzoic acid x-14: 4-Ethynylbenzeneacetic acid x-15: 4-Propargylbenzoic acid x-16: 4-Propargyloxybenzoic acid x-17: 5-Vinyl-1,3-benzenedicarboxylic acid x-18: 5,6,7,8-tetrahydro-5-(3-oxetanyl)-1,6-naphthyridine-2-carboxylic acid x-19: 4-(1,2-epoxyethyl)benzoic acid x-20: 4-Cyanobenzoic acid X-1: Isobutyric acid X-2: Benzoic acid X-3: Methacrylic acid
[0166] [d] The following compounds were used as solvents: d-1: n-propyl alcohol, d-2: ethanol, d-3: 1-butanol, d-4: isopropanol, d-5: methanol, d-6: isobutanol, d-7: sec-butanol, d-8: tert-butanol, d-9: toluene, d-10: dichloromethane, and d-11: hexane.
[0167] [B] The following compounds were used as the solvent: B-1: Propylene glycol monomethyl ether acetate B-2: Propylene glycol monomethyl ether
[0168] [Synthesis Example 1-1] (Synthesis of [A] Compound (A-1)) Compound (m-1) (molar ratio 1) and solvent (d-1) (40 parts by mass) were placed in a reaction vessel under a nitrogen atmosphere. Compound (x-1) (molar ratio 4) was added to the reaction vessel while stirring at 50°C. Next, the reaction was 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 then vacuum dried to obtain compound (A-1).
[0169] Synthesis Example 1-2 (Synthesis of [A] Compound (A-2)) Under a nitrogen atmosphere, compound (m-1) (molar ratio 1) and solvent (d-1) (100 parts by mass) were placed in a reaction vessel. Compound (x-1) (molar ratio 1) was then added to the reaction vessel with 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. To the cooled reaction solution, 900 parts by mass of solvent (B-1) was added, and then the 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.
[0170] [Synthesis Examples 1-3 to 1-27, 1-30, 1-34 to 1-39] (Synthesis of [A] Compounds (A-3) to (A-27), (A-30), and (A-34) to (A-39)) [A] Compounds (A-3) to (A-27), (A-30), and (A-34) to (A-39) 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 below were used.
[0171] Synthesis Example 1-28 (Synthesis of [A] Compound (A-28)) Under a nitrogen atmosphere, compound (m-3) (molar ratio 1) and solvent (d-10) (100 parts by mass) were placed in a reaction vessel. To the reaction vessel, compound (x-6) (molar ratio 4) was added with stirring at 40°C. Next, the reaction was 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 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.
[0172] Synthesis Example 1-29 (Synthesis of [A] Compound (A-29)) Under a nitrogen atmosphere, compound (m-3) (molar ratio 1) and solvent (d-11) (100 parts by mass) were placed in a reaction vessel. To the reaction vessel, compound (x-6) (molar ratio 4) was added with stirring at 50°C. Next, the reaction was carried out at 65°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-11), the alcohol produced by the reaction, and excess solvent (B-1) were removed using an evaporator to obtain a mixture containing compound (A-29). The concentration of components other than the solvent in the mixture containing compound (A-29) [A] was 20% by mass.
[0173] Synthesis Example 1-31 (Synthesis of [A] Compound (A-31)) Under a nitrogen atmosphere, compound (m-5) (molar ratio 1) and solvent (d-2) (100 parts by mass) were placed in a reaction vessel. To the reaction vessel, compound (x-1) (molar ratio 5) was added with stirring at 50°C. Next, the reaction was carried out at 80°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-31). The concentration of components other than the solvent in the mixture containing compound (A-31) [A] was 20% by mass.
[0174] Synthesis Example 1-32 (Synthesis of [A] Compound (A-32)) [A] Compound (A-32) was obtained in the same manner as in Synthesis Example 1-29, except that the types and amounts of the [m] compound, [x] compound, [d] solvent, and [B] solvent shown in Table 1 below were used.
[0175] Synthesis Examples 1-33 and 1-40 (Synthesis of [A] Compounds (A-33) and (A-40)) [A] Compounds (A-33) and (A-40) were obtained in the same manner as in Synthesis Example 1-31, except that the types and amounts of the [m] compound, [x] compound, [d] solvent, and [B] solvent shown in Table 1 below were used.
[0176] Synthesis Example 1-41 (Synthesis of [A] Compound (A-41)) Under a nitrogen atmosphere, compound (m-1) (molar ratio 1) and solvent (d-1) (100 parts by mass) were charged into a reaction vessel. To the reaction vessel, compounds (x-1) (molar ratio 2) and (x-6) (molar ratio 2) were successively added with 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. To the cooled reaction solution, 900 parts by mass of solvent (B-1) was added, 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-41). The concentration of components other than the solvent in the mixture containing compound (A-41) [A] was 20% by mass.
[0177] Synthesis Examples 1-42 to 1-44 (Synthesis of [A] Compounds (A-42) to (A-44)) [A] Compounds (A-42) to (A-44) were obtained in the same manner as in Synthesis Example 1-41, except that the type and amount of [x] compound shown in Table 1 below were used.
[0178] 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 below were used.
[0179]
[0180] <Preparation of Composition> The compounds [A], solvents [B], and other optional components [F] used in the preparation of the composition are shown below.
[0181] The compounds (A-1) to (A-44) synthesized above were used as the compound [A]. The compounds (a-1) to (a-2) synthesized above were used as comparative compounds.
[0182] As the solvent [B], the solvents (B-1) and (B-2) used in the synthesis of the compound [A] were used.
[0183] [F] As other optional components, the following compounds were used.
[0184] The following compounds (FF-1) to (FF-12) were used as aromatic ring-containing compounds having a molecular weight of 300 or more. FF-1: A compound represented by the following formula (FF-1) FF-2: A compound represented by the following formula (FF-2) FF-3: A compound represented by the following formula (FF-3) FF-4: A compound represented by the following formula (FF-4) FF-5: A polymer having a repeating unit represented by the following formula (FF-5) (Mw is 1,100) FF-6: A polymer having a repeating unit represented by the following formula (FF-6) (Mw is 2,211) FF-7: A polymer having a repeating unit represented by the following formula (FF-7) (Mw is 1,228) FF-8: A polymer having a repeating unit represented by the following formula (FF-8) (Mw is 2,500) FF-9: A polymer having a repeating unit represented by the following formula (FF-9) (Mw is 1,715) FF-10: A polymer having a repeating unit represented by the following formula (FF-10) (Mw is 1,000) FF-11: A polymer having a repeating unit represented by the following formula (FF-11) (Mw is 2,488) FF-12: A polymer having a repeating unit represented by the following formula (FF-12) (Mw is 1,000)
[0185]
[0186]
[0187]
[0188] The following compounds were used as optional components other than the aromatic ring-containing compound: F-1: 4-methoxyphenol F-2: Surfactant ("NBX-15" from Neos Corporation) F-3: Surfactant ("F563" from DIC Corporation) F-4: Surfactant ("DOWSIL SH28 Paint Additive" from Dow-Toray Industries, Inc.)
[0189] F-5: Compound (F-5) represented by the following formula (in the formula, "Bu" represents an n-butyl group).
[0190] F-6: Compound (F-6) represented by the following formula:
[0191] F-7: Compound (F-7) represented by the following formula:
[0192] F-8: 1,4-divinylbenzene F-9: ethylene glycol dimethacrylate F-10: pentaerythritol tetraacrylate
[0193] [Example 1-1] Preparation of Composition (J-1) As shown in Table 2-1 below, 3 parts by mass of [A] compound (A-1), 96.995 parts by mass of [B] solvent (B-1), and 0.005 parts by mass of [F] other optional component (F-1) were mixed. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) filter with a pore size of 0.2 μm to prepare composition (J-1). In Table 2-1 below, "-" indicates that the corresponding component was not used. The same applies hereinafter.
[0194] [Example 1-2] Preparation of Composition (J-2) 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 [B] solvent was 96.695 parts by mass (including the [B] solvent contained in the mixture containing the [A] compound) and the amount of [F] other optional component (F-1) were 0.005 parts by mass per 3 parts by mass of the components other than the solvent in [A] 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-2).
[0195] Examples 1-3 to 1-70: Preparation of Compositions (J-3) to (J-70) Compositions (J-3) to (J-70) were prepared in the same manner as in Example 1-2, except that the types and contents of each component were as shown in Tables 2-1 and 2-2 below.
[0196] Comparative Examples 1-1 and 1-2: Preparation of Compositions (j-1) and (j-2) Compositions (j-1) and (j-2) were prepared in the same manner as in Example 1-2, except that the types and contents of each component were as shown in Table 2-2 below.
[0197]
[0198]
[0199] <Evaluation> In Examples 2-1 to 2-70 and Comparative Examples 2-1 and 2-2, the compositions prepared in the above <Preparation of Composition> and the film-coated substrates obtained in the below <Formation of Film> were evaluated for embeddability and etching resistance by the following methods. The evaluation results are shown in Tables 3-1 and 3-2 below.
[0200] [Fillability] The composition was applied by spin coating using a spin coater (Tokyo Electron Limited's "LITHIUS Pro Z") on a substrate on which a trench pattern of 50 nm in depth and 30 nm in width had been formed. The rotation conditions of the spin coater were set so as to obtain a substrate with a film having an average thickness of 90 nm after baking. Next, H-1: heating at 400°C for 60 seconds in an air atmosphere, or H-2: heating at 400°C for 60 seconds in a nitrogen atmosphere, followed by cooling at 23°C for 60 seconds. The cross-sectional shape of the substrate was observed (200,000x magnification) using a scanning electron microscope (Hitachi High-Technologies Corporation's "S-4800") to evaluate the fillability. The fillability was evaluated as "A" (good) when the film was embedded to the bottom of the space pattern of the substrate (when there were no voids), and as "B" (poor) when the film was not embedded to the bottom of the space pattern (when there were voids).
[0201] <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.
[0202] [Etching Resistance] The film on the film-coated substrate was subjected to CF etching using an etching apparatus ("TACTRAS" manufactured by Tokyo Electron Limited). ４The 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 was calculated based on the etching rate of Comparative Example 2-1, and the ratio 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. In Table 3-2 below, "-" indicates that this is the evaluation standard for etching resistance.
[0203]
[0204]
[0205] 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 embedding ability and etching resistance compared to the comparative examples.
[0206] According to the method for producing a semiconductor substrate of the present invention, a film having excellent etching resistance and embeddability can be formed, thereby obtaining a well-patterned semiconductor substrate. According to the film-forming composition of the present invention, a film having excellent etching resistance and embeddability can be formed. Therefore, these compositions can be suitably used in the production of semiconductor devices, which are expected to become even more miniaturized in the future.
Claims
1. A method for producing a semiconductor substrate, comprising: applying a film-forming composition to a substrate; the film-forming composition containing a metal compound composed of at least a metal atom and an organic acid, and a solvent; and the organic acid being a compound represented by the following formula (1): (In formula (1), R １ represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms (wherein -L １ Except for the structure corresponding to -COOH and the structure corresponding to X. １ is an aromatic ring structure having 3 to 30 carbon atoms and a valence of r+s+t. X is a crosslinkable group. １ is a single bond or a divalent linking group. t is an integer from 0 to 2. When t is 2, two R １ are the same or different. r is an integer of 1 to 4. When r is 2 or more, multiple Xs are the same or different. s is an integer of 1 to 4. When s is 2 or more, multiple Ls are １ are the same or different.) 2. The method for producing a semiconductor substrate according to claim 1, wherein the X is a group selected from the group consisting of groups represented by any one of the following formulas (2-1) to (2-5): (In formulas (2-1), (2-2), (2-5), R ８ , R ９ , R １０ , R １１ and R １２ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ７ are each independently a divalent linking group or a single bond. １ is a bond to the atoms that make up the molecule.) 3. R ７ 3. The method for producing a semiconductor substrate according to claim 2, wherein is a divalent chain hydrocarbon group having 1 to 5 carbon atoms, --O--, or a combination thereof, or a single bond.
4. L １ The method for producing a semiconductor substrate according to claim 1, wherein is a divalent chain hydrocarbon group having 1 to 5 carbon atoms or a single bond.
5. The method for producing a semiconductor substrate according to claim 1, wherein the aromatic ring structure is an aromatic hydrocarbon ring structure having 6 to 14 carbon atoms or an aromatic heterocyclic structure having 6 to 10 carbon atoms.
6. The method for producing a semiconductor substrate according to any one of claims 1 to 5, wherein the metal atom belongs to Groups 3 to 16 of the periodic table.
7. The method for producing a semiconductor substrate according to any one of claims 1 to 5, wherein the metal atom is titanium, zirconium, hafnium, tantalum, tungsten or tin.
8. The method for manufacturing a semiconductor substrate according to any one of claims 1 to 5, wherein the substrate has a pattern.
9. A film-forming composition comprising: a metal compound constituted by at least a metal atom and an organic acid; and a solvent, wherein the organic acid is a compound represented by the following formula (1): (In formula (1), R １ represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms (wherein -L １ Except for the structure corresponding to -COOH and the structure corresponding to X. １ is an aromatic ring structure having 3 to 30 carbon atoms and a valence of r+s+t. X is a crosslinkable group. １ is a single bond or a divalent linking group. t is an integer from 0 to 2. When t is 2, two R １ are the same or different. r is an integer of 1 to 4. When r is 2 or more, multiple Xs are the same or different. s is an integer of 1 to 4. When s is 2 or more, multiple Ls are １ are the same or different.) 10. The film forming composition according to claim 9, wherein the above X is a group selected from the group consisting of groups represented by any one of the following formulas (2-1) to (2-5): (In formulas (2-1), (2-2), (2-5), R ８ , R ９ , R １０ , R １１ and R １２ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ７ are each independently a divalent linking group or a single bond. １ is a bond to the atoms that make up the molecule.) 11. R ７ The film forming composition according to claim 10, wherein is a divalent chain hydrocarbon group having 1 to 5 carbon atoms, -O-, or a combination thereof, or a single bond.
12. L １ The film forming composition according to claim 9, wherein is a divalent chain hydrocarbon group having 1 to 5 carbon atoms or a single bond.
13. The film-forming composition according to claim 9, wherein the aromatic ring structure is an aromatic hydrocarbon ring structure having 6 to 14 carbon atoms or an aromatic heterocyclic structure having 6 to 12 carbon atoms.
14. The film-forming composition according to any one of claims 9 to 13, which is used for embedding a pattern in a substrate having a pattern.
15. The film forming composition according to any one of claims 9 to 13, wherein a metal atom contained in the metal compound belongs to Groups 3 to 16 of the periodic table.
16. The film forming composition according to any one of claims 9 to 13, wherein the metal atom contained in the metal compound is titanium, zirconium, hafnium, tantalum, tungsten or tin.