Method for manufacturing a semiconductor substrate, method for forming a resist underlayer film, and cleaning solution

Abstract

Provided are: a method for producing a semiconductor substrate using a cleaning fluid excellent in terms of the property of cleaning peripheral portions of substrates and waste-liquid stability; a method for forming a resist underlayer film; and the cleaning fluid. This method for producing a semiconductor substrate comprises: a step in which a composition for resist underlayer film formation is applied directly or indirectly to a substrate; a step in which peripheral portions of the substrate are cleaned with a cleaning fluid; and a step in which after the cleaning step, a resist pattern is formed directly on or indirectly over the resist underlayer film formed in the application step. The composition for resist underlayer film formation includes a metal compound and a solvent, and the cleaning fluid includes an organic acid.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor substrate, a method for forming a resist underlayer film, and a cleaning liquid.

Background Art

[0002] In the manufacture of semiconductor substrates and the like, a metal hard mask composition as a resist underlayer film has been proposed (see Japanese Patent Application Laid-Open No. 2013-185155). As a manufacturing apparatus for semiconductor substrates and the like, for example, a clean track (manufactured by Tokyo Electron Limited) or the like is used. This apparatus is an apparatus that can consistently perform processes such as spin coating, EBR (Edge Bead Removal), back rinsing, and baking. EBR is a process of cleaning the edge portion (peripheral portion) of a substrate with a cleaning liquid for the purpose of removing a coating film formed on the substrate (wafer) by spin coating. This apparatus automatically transports the substrate, but it is necessary to perform EBR so as not to contaminate the clamp portion that holds the substrate. If the edge portion of the substrate cannot be cleaned by EBR, the clamp may be contaminated, which may cause defects and reduce the yield of the device. When manufacturing a semiconductor substrate or the like, it is generally required that the edge portion of the substrate can be cleaned by EBR. As a cleaning liquid used for EBR, a mixed liquid of propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether (30:70, mass ratio) and the like are widely used in the EBR process of a resist film, a silicon-containing film, and an organic underlayer film.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The cleaning solution must have cleaning properties that allow for the removal of metal hard masks from the peripheral edges of the substrate. Furthermore, when a multilayer resist process is performed in a single apparatus, wastewater from multiple processes is often discharged through the same piping. Therefore, the cleaning solution must have wastewater stability to suppress unintended events such as metal deposition in the piping due to interference with other wastewater.

[0005] The present invention has been made based on the circumstances described above, and its purpose is to provide a method for manufacturing a semiconductor substrate using a cleaning solution that is excellent in cleaning the peripheral edge of the substrate and in drainage stability, a method for forming a resist underlayer film, and a cleaning solution. [Means for solving the problem]

[0006] In one embodiment, the present invention is A step of coating a substrate with a resist underlayer film formation composition, either directly or indirectly. The process involves cleaning the peripheral edge of the above substrate with a cleaning solution, After the above cleaning step, a step is made to directly or indirectly form a resist pattern on the resist underlayer film formed by the above coating step. Includes, The above resist underlayer film forming composition, Metal compounds (hereinafter also referred to as "[A] compounds") and The solvent (hereinafter also referred to as "[B] solvent") and It contains, The present invention relates to a method for manufacturing a semiconductor substrate, wherein the above-mentioned cleaning solution contains an organic acid (hereinafter also referred to as "[E] organic acid").

[0007] Furthermore, in another embodiment, the present invention states that A step of coating a resist underlayer film formation composition directly or indirectly onto a substrate, A step of cleaning the peripheral edge of the above substrate with a cleaning solution, Includes, The above resist underlayer film forming composition, Metal compounds and, solvent and It contains, The present invention relates to a method for forming a resist underlayer film, wherein the above-mentioned cleaning solution contains an organic acid.

[0008] Furthermore, in yet another embodiment, the present invention A step of coating a resist underlayer film formation composition directly or indirectly onto a substrate, A cleaning solution used in a method for manufacturing a semiconductor substrate, which includes a step of cleaning the peripheral edge of the substrate with a cleaning solution, The above resist underlayer film forming composition, Metal compounds and, solvent and It contains, The above-mentioned cleaning solution relates to a cleaning solution that contains an organic acid. [Effects of the Invention]

[0009] The semiconductor substrate manufacturing method uses a cleaning solution with excellent cleaning properties and drainage stability to clean the peripheral edges of the substrate, thus enabling the efficient production of high-quality semiconductor substrates. The resist underlayer formation method also uses a cleaning solution with excellent cleaning properties and drainage stability, allowing for the efficient formation of the desired resist underlayer. The cleaning solution excels in both cleaning properties and drainage stability. Therefore, these methods are suitable for use in the manufacturing of semiconductor devices, where further miniaturization is expected in the future. [Modes for carrying out the invention]

[0010] The following describes in detail the method for manufacturing a semiconductor substrate, the method for forming a resist underlayer film, and the cleaning solution according to each embodiment of the present invention. A preferred combination of embodiments is also preferable.

[0011] Method for manufacturing semiconductor substrates The method for manufacturing the semiconductor substrate includes a step of coating a resist underlayer film-forming composition (hereinafter also referred to as "composition") directly or indirectly on the substrate (hereinafter also referred to as "coating step"), a step of cleaning the peripheral portion of the substrate with a cleaning liquid (hereinafter also referred to as "cleaning step"), and a step of forming a resist pattern directly or indirectly on the resist underlayer film formed by the coating step after the cleaning step (hereinafter also referred to as "resist pattern forming step"). Further, the method for manufacturing the semiconductor substrate preferably includes a step of forming a pattern on the resist underlayer film by etching using the resist pattern as a mask (hereinafter also referred to as "etching step").

[0012] The peripheral portion of the substrate refers to, for example, the outer peripheral portion of the substrate where the length from the outer peripheral end of the substrate to the center of the substrate is within 3.0 cm. The length from the outer peripheral end of the substrate to the center of the substrate can be 2.0 cm, 1.0 cm, 0.5 cm, or 0.2 cm.

[0013] The method for manufacturing the semiconductor substrate may further include a step of forming an organic underlayer film directly or indirectly on the substrate having the resist underlayer film formed by the coating step (hereinafter also referred to as "organic underlayer film forming step") as needed, before the resist pattern forming step.

[0014] The method for manufacturing the semiconductor substrate may further include a step of forming a silicon-containing film directly or indirectly on the substrate having the resist underlayer film formed by the coating step (hereinafter also referred to as "silicon-containing film forming step") as needed, before the resist pattern forming step.

[0015] Hereinafter, the resist underlayer film-forming composition and cleaning liquid used in the method for manufacturing the semiconductor substrate, and each step in the case of including the organic underlayer film forming step and silicon-containing film forming step which are optional steps will be described.

[0016] <Resist Underlayer Film-Forming Composition> The composition contains a [A] compound and a [B] solvent. The composition may contain other optional components as long as the effects of the present invention are not impaired.

[0017] [[A] compound] [A] compound refers to a compound containing a metal atom and an oxygen atom. Examples of the metal atom constituting the [A] compound include metal atoms of Groups 3 to 16 of the periodic table (excluding silicon atoms), etc. The [A] compound may have one or more metal atoms.

[0018] Examples of the Group 3 metal atom include scandium, yttrium, lanthanum, cerium, etc. Examples of the Group 4 metal atom include titanium, zirconium, hafnium, etc. Examples of the Group 5 metal atom include vanadium, niobium, tantalum, etc. Examples of the Group 6 metal atom include chromium, molybdenum, tungsten, etc. Examples of the Group 7 metal atom include manganese, rhenium, etc. Examples of the Group 8 metal atom include iron, ruthenium, osmium, etc. Examples of the Group 9 metal atom include cobalt, rhodium, iridium, etc. Examples of the Group 10 metal atom include nickel, palladium, platinum, etc. Examples of the Group 11 metal atom include copper, silver, gold, etc. Examples of the Group 12 metal atom include zinc, cadmium, mercury, etc. Examples of the Group 13 metal atom include aluminum, gallium, indium, etc. Examples of the Group 14 metal atom include germanium, tin, lead, etc. Examples of the Group 15 metal atom include antimony, bismuth, etc. Examples of the Group 16 metal atom include tellurium, etc.

[0019] The metal atoms constituting the above [A] compound are preferably from groups 3 to 16, more preferably from groups 4 to 14, even more preferably from groups 4, 5, and 14, and particularly preferably from group 4. Specifically, titanium, zirconium, hafnium, tantalum, tungsten, tin, or combinations thereof are even more preferred.

[0020] The components other than the metal atoms constituting the above [A] compound (hereinafter also referred to as "[x] compound") are preferably organic acids (hereinafter also referred to as "[a] organic acids"), hydroxy acid esters, β-diketones, α,α-dicarboxylic acid esters, and amine compounds. Here, "organic acid" refers to an organic compound that exhibits acidity, and "organic compound" refers to a compound having at least one carbon atom.

[0021] [a] Examples of organic acids include carboxylic acids, sulfonic acids, sulfinic acids, organic phosphinic acids, organic phosphonic acids, phenols, enols, thiols, acid imides, oximes, sulfonamides, and the like.

[0022] Examples of the carboxylic acids mentioned above include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butanoic 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; dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, and tartaric acid; and carboxylic acids having three or more carboxyl groups, such as citric acid.

[0023] Examples of the above-mentioned sulfonic acids include benzenesulfonic acid and p-toluenesulfonic acid.

[0024] Examples of the above-mentioned sulfinic acid include benzenesulfinic acid and p-toluenesulfinic acid.

[0025] Examples of the above-mentioned organic phosphinic acids include diethylphosphinic acid, methylphenylphosphinic acid, and diphenylphosphinic acid.

[0026] Examples of the above-mentioned organic phosphonic acids include methylphosphonic acid, ethylphosphonic acid, t-butylphosphonic acid, cyclohexylphosphonic acid, and phenylphosphonic acid.

[0027] Examples of the above-mentioned phenols include monovalent phenols such as phenol, cresol, 2,6-xylenol, and naphthol; Divalent phenols such as catechol, resorcinol, hydroquinone, and 1,2-naphthalenediol; Examples include pyrogallol, 2,3,6-naphthalentriol, and other phenols with a valency of three or higher.

[0028] Examples of the above-mentioned enols include 2-hydroxy-3-methyl-2-butene and 3-hydroxy-4-methyl-3-hexene.

[0029] Examples of the thiols mentioned above include mercaptoethanol and mercaptopropanol.

[0030] Examples of the above-mentioned acid imides include carboxylic acid imides such as maleimide and succinimide, as well as sulfonamides such as di(trifluoromethanesulfonic acid)imide and di(pentafluoroethanesulfonic acid)imide.

[0031] Examples of the oximes mentioned above include aldoximes such as benzaldoxime and salicylaldoxime, as well as ketoximes such as diethylketoxime, methylethylketoxime, and cyclohexanone oxime.

[0032] Examples of the above-mentioned sulfonamides include methyl sulfonamide, ethyl sulfonamide, benzene sulfonamide, and toluene sulfonamide.

[0033] [a] As organic acids, carboxylic acids are preferred, monocarboxylic acids are more preferred, and methacrylic acid and benzoic acid are even more preferred.

[0034] Examples of the hydroxy acid esters mentioned above include glycolic acid esters, lactate esters, 2-hydroxycyclohexane-1-carboxylic acid esters, salicylic acid esters, and the like.

[0035] Examples of the above-mentioned β-diketones include 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-ethyl-2,4-pentanedione.

[0036] Examples of the above-mentioned β-ketoesters include acetoacetic acid esters, α-alkyl-substituted acetoacetic acid esters, β-ketopentanoic acid esters, benzoyl acetate esters, and 1,3-acetonedicarboxylic acid esters.

[0037] Examples of the above-mentioned β-ketoesters include acetoacetic acid esters, α-alkyl-substituted acetoacetic acid esters, β-ketopentanoic acid esters, benzoyl acetate esters, and 1,3-acetonedicarboxylic acid esters.

[0038] Examples of amine compounds include diethanolamine and triethanolamine.

[0039] The above [A] compound is preferably a metal compound composed of a metal atom and an [a] organic acid, more preferably a metal compound composed of a metal atom from Group 4, Group 5, and Group 14 and a carboxylic acid, and even more preferably a metal compound composed of titanium, zirconium, hafnium, tantalum, tungsten, or tin and methacrylic acid or benzoic acid. The form of [a] organic acid in the [A] compound also includes organic acid anions obtained by removing hydrogen ions from the [a] organic acid.

[0040] [A] Compound may contain one or more of the above-mentioned metal compounds.

[0041] [A] Compound may contain one or more [a] organic acids.

[0042] The lower limit of the content of compound [A] in the total components contained in the composition is preferably 2% by mass, more preferably 4% by mass, and still more preferably 6% by mass. The upper limit of the above content is preferably 30% by mass, more preferably 20% by mass, and still more preferably 15% by mass.

[0043] [[A] Method for synthesizing compounds] [A] Compounds can be synthesized, for example, by a hydrolysis condensation reaction using a metal-containing compound (hereinafter also referred to as "[b] metal-containing compound"), or by a ligand exchange reaction using a metal-containing compound. Here, "hydrolysis condensation reaction" refers to a reaction in which the hydrolyzable group of the metal-containing compound is hydrolyzed and converted to -OH, and the two resulting -OH groups undergo dehydration condensation to form -O-.

[0044] ([b] Metal-containing compounds) [b] The metal-containing compound is a metal compound (b1) having a hydrolyzable group, a hydrolyzate of a metal compound (b1) having a hydrolyzable group, a hydrolyzed condensate of a metal compound (b1) having a hydrolyzable group, or a combination thereof. The metal compound (b1) can be used alone or in combination of two or more types.

[0045] Examples of the hydrolyzable groups mentioned above include halogen atoms, alkoxy groups, and acyloxy groups.

[0046] Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like.

[0047] Examples of the alkoxy groups mentioned above include methoxy groups, ethoxy groups, n-propoxy groups, isopropoxy groups, and n-butoxy groups.

[0048] Examples of the above-mentioned acyloxy groups include acetoxy group, ethylyloxy group, propionyloxy group, butyryloxy group, t-butyryloxy group, t-amiryloxy group, n-hexanecarbonyloxy group, and n-octanecarbonyloxy group.

[0049] The hydrolyzable groups mentioned above are preferably alkoxy groups and acyloxy groups, and more preferably isopropoxy groups and acetoxy groups.

[0050] [b] When the metal-containing compound is a hydrolysis condensate of the metal compound (b1), the hydrolysis condensate of the metal compound (b1) may be a hydrolysis condensate of the metal compound (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 (b1) may contain a metalloid atom to the extent that the effects of the present invention are not impaired. 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 (b1) is usually less than 50 atomic percent of the total amount of metal atoms and metalloid atoms in the hydrolysis condensate. The upper limit of the content of the metalloid atom is preferably 30 atomic percent and more preferably 10 atomic percent of the total amount of metal atoms and metalloid atoms in the hydrolysis condensate.

[0051] Examples of metal compounds (b1) include the compound represented by the following formula (α) (hereinafter also referred to as "[m] compound").

[0052] [ka]

[0053] In the above formula (α), M is a metal atom. L is a ligand. a is an integer from 0 to 2. If a is 2, multiple Ls may be the same or different. Y is a hydrolyzable group selected from halogen atoms, alkoxy groups, and acyloxy groups. b is an integer from 2 to 6. Multiple Ys may be the same or different. Note that L is a ligand that does not correspond to Y.

[0054] Examples of metal atoms represented by M include those similar to those exemplified as metal atoms constituting the metal compounds contained in compound [A].

[0055] Ligands represented by L include monodentate ligands and polydentate ligands.

[0056] Examples of the monodentate ligands mentioned above include hydroxo ligands, carboxyl ligands, amide ligands, and ammonia.

[0057] Examples of the above-mentioned amide ligands include unsubstituted amide ligands (NH2), methylamide ligands (NHMe), dimethylamide ligands (NMe2), diethylamide ligands (NEt2), and dipropylamide ligands (NPr2).

[0058] Examples of the polydentate ligands mentioned above include hydroxy acid esters, β-diketones, β-ketoesters, β-dicarboxylic acid esters, hydrocarbons having π bonds, and diphosphines.

[0059] Examples of the hydroxy acid esters mentioned above include glycolic acid esters, lactate esters, 2-hydroxycyclohexane-1-carboxylic acid esters, salicylic acid esters, and the like.

[0060] Examples of the above-mentioned β-diketones include 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-ethyl-2,4-pentanedione.

[0061] Examples of the above-mentioned β-ketoesters include acetoacetic acid esters, α-alkyl-substituted acetoacetic acid esters, β-ketopentanoic acid esters, benzoyl acetate esters, and 1,3-acetonedicarboxylic acid esters.

[0062] Examples of the above-mentioned β-dicarboxylic acid esters include malonic acid diesters, α-alkyl-substituted malonic acid diesters, α-cycloalkyl-substituted malonic acid diesters, and α-aryl-substituted malonic acid diesters.

[0063] Examples of hydrocarbons having the above-mentioned π bond include, Chain-like olefins such as ethylene and propylene; Cyclopentene, cyclohexene, norbornene, and other cyclic olefins; Chain-like dienes such as butadiene and isoprene; Cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norbornadiene; Examples include aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene, and indene.

[0064] Examples of the above-mentioned 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.

[0065] Examples of halogen atoms represented by Y include fluorine, chlorine, bromine, and iodine atoms.

[0066] Examples of alkoxy groups represented by Y include methoxy, ethoxy, propoxy, and butoxy groups.

[0067] Examples of acyloxy groups represented by Y include acetoxy group, ethylyloxy group, butyryloxy group, t-butyryloxy group, t-amiryloxy group, n-hexanecarbonyloxy group, and n-octanecarbonyloxy group.

[0068] For Y, alkoxy groups and acyloxy groups are preferred, and isopropoxy groups and acetoxy groups are more preferred.

[0069] For b, 3 and 4 are preferred, with 4 being more preferred.

[0070] [b] Preferred metal-containing compounds are metal alkoxides that have not undergone hydrolysis or hydrolysis condensation, and metal acyloxides that have not undergone hydrolysis or hydrolysis condensation.

[0071] [b]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 pentane-butoxide, tungsten pentamethoxide, tungsten pentane-butoxide, tungsten hexaethoxide, tungsten hexane-butoxide, iron chloride, zinc diisopropoxide, zinc acetate dihydrate, ortho Tetrabutyl titanate, titanium tetra-n-butoxide, titanium tetra-n-propoxide, zirconium di-n-butoxide bis(2,4-pentane dionate), 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) Examples include (3-) 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 tetraisopropoxide, tin tetra-n-butoxide, lanthanum oxide, yttrium oxide, etc.

[0072] Among these, metal alkoxides and metal acyloxides are preferred, metal alkoxides are more preferred, and titanium, zirconium, hafnium, tantalum, tungsten, and tin alkoxides are even more preferred.

[0073] [A] When using an organic acid in the synthesis of the compound, the lower limit of the amount of organic acid used is preferably 1 mole and more preferably 2 moles per mole of the metal-containing compound. On the other hand, the upper limit of the amount of organic acid used is preferably 6 moles and more preferably 5 moles per mole of the metal-containing compound.

[0074] [A] In the synthesis reaction of the compound, in addition to the metal compound (b1) and the organic acid [a], compounds that can act as a polydentate ligand represented by L in the compound of formula (α) above, or compounds that can act as a bridging ligand, etc., may be added. Examples of compounds that can act as bridging ligands include compounds having multiple hydroxyl groups, isocyanate groups, amino groups, ester groups, and amide groups.

[0075] [b] A method for carrying out a hydrolysis condensation reaction using a metal-containing compound is, for example, to carry out a hydrolysis condensation reaction of the [b] metal-containing compound in a solvent containing water. In this case, other compounds having hydrolyzable groups may be added as needed. The lower limit of the amount of water used in this hydrolysis condensation reaction is preferably 0.2 moles, more preferably 1 mole, and even more preferably 3 moles, relative to the hydrolyzable groups of the [b] metal-containing compound. The upper limit of the amount of water is preferably 20 moles, more preferably 15 moles, and even more preferably 10 moles.

[0076] [b] A method for carrying out a ligand exchange reaction using a metal-containing compound is, for example, a method of mixing the [b] metal-containing compound and the [a] organic acid. In this case, the mixing may be done in a solvent or without a solvent. In addition, a base such as triethylamine may be added to the above mixing as needed. The amount of the base to be added is, for example, 1 to 200 parts by mass per 100 parts by mass of the total amount of the [b] metal-containing compound and the [a] organic acid used.

[0077] [A] The solvent used in the synthesis reaction of the compound (hereinafter also referred to as "[d] solvent") is not particularly limited, and for example, the same solvent as those exemplified as [B] solvent described later 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.

[0078] [A] When solvent [d] is used in the synthesis reaction of compound [A], the solvent used may be removed after the reaction, or it may be used as the [B] solvent of the resist underlayer film forming composition without being removed after the reaction.

[0079] [[B] solvent] [B] The solvent is not particularly limited as long as it is capable of dissolving or dispersing at least the [A] compound and other optional components. The composition may contain one or more [B] solvents.

[0080] [B] Examples of solvents include organic solvents. Examples of organic solvents include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, nitrogen-containing solvents, sulfur-containing solvents, etc.

[0081] Examples of alcohol-based solvents include monoalcohol-based solvents such as methanol, ethanol, and n-propanol, and polyhydric alcohol-based solvents such as ethylene glycol, 1,2-propylene glycol, triethylene glycol, and tripropylene glycol.

[0082] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and 2-heptanone, and cyclic ketone solvents such as cyclohexanone.

[0083] Examples of ether-based solvents include linear ether solvents such as n-butyl ether, polyhydric alcohol 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.

[0084] Examples of ester solvents include carbonate solvents such as diethyl carbonate, acetic acid monoester solvents such as methyl acetate, ethyl acetate, and butyl acetate, lactone solvents such as γ-butyrolactone, polyhydric alcohol partial ether carboxylate solvents such as diethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate, and lactate ester solvents such as methyl lactate and ethyl lactate.

[0085] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0086] Examples of sulfur-containing solvents include linear sulfur-containing solvents such as dimethyl sulfone and dimethyl sulfoxide, and cyclic sulfur-containing solvents such as sulfolane.

[0087] Other examples include aromatic solvents such as toluene, xylene, and mesitylene.

[0088] [B] The solvent is preferably an ether-based solvent, an ester-based solvent, a ketone-based solvent, or a combination thereof; more preferably a polyhydric alcohol partial ether-based solvent, an acetate monoester-based solvent, a polyhydric alcohol partial ether carboxylate-based solvent, a linear ketone-based solvent, or a combination thereof; and even more preferably propylene glycol monoethyl ether, butyl acetate, propylene glycol monomethyl ether acetate, 2-heptanone, or a combination thereof.

[0089] The lower limit of the content of solvent [B] relative to the total amount of compound [A] and solvent [B] is more preferably 50% by mass, more preferably 60% by mass, and more preferably 70% by mass. The upper limit of the above content is more preferably 99% by mass, more preferably 95% by mass, and more preferably 90% by mass. By setting the content of solvent [B] within the above range, the preparation of the composition can be facilitated and the applicability can be improved.

[0090] [Other optional components] The composition may also contain other components besides those mentioned above, such as acid generators, polymer additives, polymerization inhibitors, surfactants, and the like.

[0091] If the composition contains other optional components, the amount of these components in the composition can be appropriately determined depending on the type and function of the other optional components used.

[0092] An acid generator is a compound that generates acid upon irradiation with radiation and / or heating. The composition may contain one or more acid generators.

[0093] Examples of acid generators include onium salt compounds and N-sulfonyloxyimide compounds.

[0094] The composition, by containing polymer additives, can further improve its coating properties and film continuity on substrates and organic underlayer films. The composition may contain one or more polymer additives.

[0095] Examples of polymer additives include (poly)oxyalkylene polymer compounds, fluorine-containing polymer compounds, and non-fluorine polymer compounds.

[0096] Examples of (poly)oxyalkylene polymer compounds 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, 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, and alkylene oxyalkylenes to acetylene alcohols such as 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,5-dimethyl-3-hexine-2,5-diol, and 3-methyl-1-butyne-3-ol. Examples include acetylene ethers obtained by addition polymerization of sides, (poly)oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurylate, 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 phosphate esters such as (poly)oxyethylene stearyl phosphate, and (poly)oxyalkylene alkylamines such as polyoxyethylene laurylamine.

[0097] Examples of fluorine-containing polymer compounds include the compounds described in Japanese Patent Publication No. 2011-89090. Examples of fluorine-containing polymer compounds include compounds containing repeating units derived from a (meth)acrylate compound having a fluorine atom and repeating units derived from a (meth)acrylate compound having two or more (preferably five or more) alkylene oxy groups (preferably ethylene oxy groups, propylene oxy groups).

[0098] Examples of non-fluorinated 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 (-(CH2CH2O) n Examples include compounds having a structure (n=1~17) that contain one or more repeating units derived from (meth)acrylate monomers such as (meth)acrylate.

[0099] The composition may have enhanced storage stability by containing polymerization inhibitors. The composition may contain one or more polymerization inhibitors.

[0100] Examples of polymerization inhibitors include hydroquinone compounds such as 4-methoxyphenol and 2,5-di-tert-butylhydroquinone, and nitroso compounds such as N-nitrosophenylhydroxylamine and its aluminum salt.

[0101] The composition, by containing a surfactant, can further improve its coating properties and film continuity on substrates and organic underlayer films. The composition may contain one or more surfactants.

[0102] Examples of commercially available surfactants include "Newcol 2320", "Newcol 714-F", "Newcol 723", "Newcol 2307", and "Newcol 2303 (all from Nippon Emulsifier Co., Ltd.), "Pionin D-1107-S", "Pionin D-1007", "Pionin D-1106-DIR", "New Calgen TG310", "New Calgen TG310", "Pionin D-6105-W", "Pionin D-6112", "Pionin D-6512" (all from Takemoto Oil & Fat Co., Ltd.), "Surfinol 420", "Surfinol 440", "Surfinol 465", "Surfinol 2502" (all from Nippon Air Products Co., Ltd.), "Megafuck F171", "Same F172", "Same F173", "Same F176", "Same F177", "Same F141", "Same F142", "Same F143", "Same F1 Examples include "44", "R30", "F437", "F475", "F479", "F482", "F562", "F563", "F780", "R-40", "DS-21", "RS-56", "RS-90", and "RS-72-K" (all from DIC Corporation), "Florard FC430", "FC431" (both from Sumitomo 3M Co., Ltd.), "Asahi Guard AG710", "Surflon S-382", "SC-101", "SC-102", "SC-103", "SC-104", "SC-105", and "SC-106" (all from AGC Inc.), "FTX-218", and "NBX-15" (from Neos Co., Ltd.).

[0103] [Method for preparing a composition for forming a resist underlayer film] The resist underlayer film forming composition can be prepared by mixing [A] compound, [B] solvent, and optionally any other components in predetermined proportions, and preferably by filtering the resulting mixture through a membrane filter with a pore size of 0.5 μm or less.

[0104] <Cleaning solution> The cleaning solution contains [E] an organic acid. Preferably, the cleaning solution further contains an organic solvent (hereinafter also referred to as "[G] organic solvent"). The cleaning solution may also contain water as a solvent other than the organic solvent. The cleaning solution may also contain other optional components as long as they do not impair the effects of the present invention. Examples of optional components include the components exemplified as ligands represented by L in the above formula (α).

[0105] [[E]organic acid] [E] The organic acid is an organic acid that is not a polymer. Adding [E] The organic acid to the cleaning solution facilitates the removal of films formed on the periphery of the substrate. The lower limit of the molecular weight of [E] The organic acid is preferably 45, more preferably 55, even more preferably 65, and particularly preferably 70, from the viewpoint of drainage stability. The upper limit of the molecular weight of [C] The organic acid is preferably 500, more preferably 400, and even more preferably 300. [E] The organic acid can be used alone or in combination of two or more types. [A] The organic acid used in the synthesis of compounds can be suitably adopted as [E] The organic acid used in the synthesis of compounds [A].

[0106] [E] As organic acids, carboxylic acids are preferred. More specifically, for example, carboxylic acids consisting of an aliphatic saturated hydrocarbon group and / or an aromatic hydrocarbon group and a carboxyl group, such as formic acid, acetic acid, propionic acid, butanoic acid (butyric acid), isobutanoic acid (isobutyric acid), pentanoic acid, hexanoic acid, 2-ethylhexanoic acid, cyclohexanecarboxylic acid, cyclohexylacetic acid, 1-adamantanecarboxylic acid, benzoic acid, phenylacetic acid, etc. Fluorine atom-containing monocarboxylic acids such as difluoroacetic acid, trifluoroacetic acid, pentafluoropropanoic acid, heptafluorobutanoic acid, fluorophenylacetic acid, and difluorobenzoic acid. Monocarboxylic acids containing heteroatoms other than fluorine atoms in the portion other than the carboxyl group, such as 10-hydroxydecanoic acid, 5-oxohexanoic acid, 3-methoxycyclohexanecarboxylic acid, camphorcarboxylic acid, dinitrobenzoic acid, nitrophenylacetic acid, lactic acid, glycolic acid, glyceric acid, salicylic acid, anisic acid, gallic acid, furancarboxylic acid, etc. Unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 3-butenic acid, angelic acid, tigric acid, 4-pentenoic acid, cinnamic acid, sorbic acid, propiolic acid, and 2-butic acid. Polycarboxylic acids consisting of single bonds, aliphatic saturated hydrocarbon groups and / or aromatic hydrocarbon groups and multiple carboxyl groups, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, dodecanedicarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, cyclohexanehexacarboxylic acid, 1,4-naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, etc. Partial esterified polycarboxylic acid, Fluorine atom-containing polycarboxylic acids such as difluoromalonic acid, tetrafluorophthalic acid, and hexafluoroglutaric acid, Polycarboxylic acids such as tartaric acid, citric acid, malic acid, tartaric acid, diglycolic acid, and iminodiacetic acid, which contain heteroatoms other than fluorine atoms in the portion other than the carboxyl group. Examples include unsaturated polycarboxylic acids such as maleic acid, fumaric acid, and aconitic acid.

[0107] [E] The organic acid is preferably an unsaturated carboxylic acid, more preferably an unsaturated monocarboxylic acid, and even more preferably at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, and 3-butenic acid, from the viewpoint of detergency and drainage stability.

[0108] The lower limit of the content of [E] organic acid in the total components contained in the cleaning solution is preferably 0.5% by mass, more preferably 1% by mass, even more preferably 2% by mass, and particularly preferably 3 parts by mass. The upper limit of the above content is preferably 80% by mass, more preferably 70% by mass, even more preferably 65% ​​by mass, and particularly preferably 60% by mass. By setting the content of [E] organic acid within the above range, the cleaning performance and drainage stability can be further improved.

[0109] [[G] Organic solvents] As the [G] organic solvent suitably contained in the cleaning solution, the above organic solvent exemplified as the [B] solvent contained in the resist underlayer film forming composition can be used.

[0110] The above [G] organic solvent is preferably at least one selected from the group consisting of the above ketone solvents and the above ester solvents, more preferably the above linear ketone solvent, the above acetate monoester solvent, the above polyhydric alcohol partial ether carboxylate solvent or a combination thereof, and even more preferably butyl acetate, propylene glycol monomethyl ether acetate, 2-heptanone or a combination thereof.

[0111] The lower limit of the content of the organic solvent [G] in relation to the total amount of the organic acid [E] and the organic solvent [G] is more preferably 20% by mass, more preferably 30% by mass, and more preferably 35% by mass. The upper limit of the above content is more preferably 99% by mass, more preferably 98% by mass, and more preferably 95% by mass.

[0112] [Method for preparing the cleaning solution] The washing solution can be prepared by mixing [E] an organic acid and, if necessary, [G] an organic solvent or other optional components in a predetermined ratio, and preferably by filtering the resulting mixture through a membrane filter with a pore size of 0.5 μm or less.

[0113] [Coating Process] In the coating process, the resist underlayer film forming composition is applied to the substrate directly or indirectly. The method of applying the resist underlayer film forming composition is not particularly limited and can be carried out by any suitable method, such as rotary coating, casting coating, or roll coating. A coating film is formed as a result, and the resist underlayer film is formed by the volatilization of the solvent [B].

[0114] Examples of substrates include metal or metalloid substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, with silicon substrates being preferred among these. The above substrate may also be a substrate on which a silicon nitride film, alumina film, silicon dioxide film, tantalum nitride film, titanium nitride film, etc., is formed.

[0115] 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 60 nm. The method for measuring the average thickness is as described in the examples.

[0116] The method for manufacturing the semiconductor substrate preferably further includes a step of heating the coating film formed by the above coating step (hereinafter also referred to as the "heating step"). Heating the coating film promotes the formation of the resist underlayer film. More specifically, heating the coating film promotes the volatilization of the [B] solvent, etc.

[0117] The above-mentioned coating film is usually heated under atmospheric conditions, but may also be heated under a nitrogen atmosphere. The lower limit of the heating temperature is preferably 150°C, and more preferably 200°C. The upper limit of the above temperature is preferably 600°C, and more preferably 500°C. The lower limit of the heating time is preferably 15 seconds, and more preferably 30 seconds. The upper limit of the above time is preferably 1,200 seconds, and more preferably 600 seconds.

[0118] [Organic lower layer film formation process] In this process, prior to the resist pattern formation process, an organic underlayer film is formed directly or indirectly on the substrate having the resist underlayer film formed by the coating process.

[0119] An organic underlayer can be formed by coating with an organic underlayer-forming composition. Methods for forming an organic underlayer by coating with an organic underlayer-forming composition include, for example, directly or indirectly coating a substrate having the resist underlayer with the organic underlayer-forming composition, and then curing the resulting coating by heating or exposure. Examples of organic underlayer-forming compositions include JSR Corporation's "HM8006". The heating and exposure conditions can be appropriately determined depending on the type of organic underlayer-forming composition used.

[0120] [Silicon-containing film formation process] In this process, prior to the resist pattern formation process, a silicon-containing film is formed directly or indirectly on the substrate having the resist underlayer film formed by the coating process.

[0121] Examples of cases in which a silicon-containing film is indirectly formed on a substrate having the resist underlayer include cases where a surface modification film of the resist underlayer is formed on the resist underlayer.

[0122] Silicon-containing films can be formed by coating with a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. A method for forming a silicon-containing film by coating with a silicon-containing film-forming composition includes, for example, directly or indirectly coating the silicon-containing film-forming composition onto the resist underlayer and curing the resulting coated film by exposure and / or heating. Commercially available silicon-containing film-forming compositions include, for example, "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all manufactured by JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxidnitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0123] [Washing process] In this step, the peripheral edge of the substrate is cleaned with a cleaning solution. The cleaning solution can be suitably used as the cleaning solution.

[0124] The cleaning method is not particularly limited, and known methods can be used. Typically, first, the substrate on which various films are formed is rotated at a predetermined speed. Next, while discharging cleaning fluid from a cleaning fluid discharge nozzle, the nozzle is moved at a predetermined speed from the outer edge of the rotating substrate toward the center of the substrate. When the cleaning fluid discharge nozzle has moved a predetermined distance, its movement is stopped, and the cleaning fluid is discharged for a predetermined time. After that, the discharge of cleaning fluid from the cleaning fluid discharge nozzle is stopped, and the substrate is dried as necessary to complete the cleaning. The rotation speed of the substrate, the amount of cleaning fluid discharged per unit time, the movement speed and distance of the cleaning fluid discharge nozzle, and the time of cleaning fluid discharge after the movement of the cleaning fluid discharge nozzle is stopped can be appropriately set according to the size of the substrate, the number, type and thickness of the films formed, and the cleaning area.

[0125] After coating the substrate with the resist underlayer film forming composition, the cleaning step can be performed with or without the heating step. If the cleaning step is performed after the coating step without the heating step, it is preferable to perform the heating step after the cleaning step.

[0126] [Resist pattern formation process] In this step, after the cleaning step described above, a resist pattern is formed directly or indirectly on the resist underlayer film. Methods for performing this step include, for example, using a resist composition, using a nanoimprint method, or using a self-assembling composition. An example of indirectly forming a resist pattern on the resist underlayer film is when the semiconductor substrate manufacturing method includes the silicon-containing film formation step described above, and a resist pattern is formed on the silicon-containing film.

[0127] The method using the above-mentioned resist composition specifically involves coating the resist composition so that the resist film to be formed has a predetermined thickness, and then pre-baking as needed to volatilize the solvent in the coated film, thereby forming the resist film.

[0128] Examples of the above-mentioned resist compositions include positive or negative type chemically amplified resist compositions containing a radiation-sensitive acid generator, positive type resist compositions containing an alkali-soluble resin and a quinone diazide-based photosensitive agent, and negative type resist compositions containing an alkali-soluble resin and a crosslinking agent. In this process, commercially available resist compositions can also be used as is.

[0129] Next, the resist film formed above is exposed by selective radiation irradiation. The radiation used for exposure can be appropriately selected depending on the type of radiation-sensitive acid generator used in the resist composition. Examples include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays, as well as particle beams such as electron beams, molecular beams, and ion beams. Among these, far ultraviolet light is preferred, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F2 excimer laser light (wavelength 157 nm), Kr2 excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm), or extreme ultraviolet light (wavelength 13.5 nm, hereinafter also referred to as "EUV") is more preferred, and KrF excimer laser light, ArF excimer laser light, or EUV is even more preferred.

[0130] After the exposure described above, post-baking can be performed 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.

[0131] 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 basic aqueous solutions include ammonia, triethanolamine, tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide. These basic aqueous solutions may also have appropriate amounts of water-soluble organic solvents such as methanol and ethanol, or surfactants added to them. In the case of organic solvent development, examples of the developer include the various organic solvents exemplified as solvent [B] in the above-mentioned composition.

[0132] After development with the above-mentioned developer, the resist pattern is formed by washing and drying.

[0133] [Etching process] In this process, a pattern is formed on the resist underlayer film by etching using the resist pattern described above as a mask. The etching can 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 etchings are preferred. When multiple etchings are performed, the silicon-containing film, organic underlayer film, resist underlayer film, and substrate are etched sequentially in that order. 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 this dry etching, for example, a gas plasma such as oxygen plasma is used. A semiconductor substrate having a predetermined pattern is obtained by the above etching.

[0134] Dry etching can be performed, for example, using 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. Examples include fluorine-based gases such as CHF3, CF4, C2F6, C3F8, SF6; chlorine-based gases such as Cl2, BCl3; oxygen-based gases such as O2, O3, H2O; reducing gases such as H2, NH3, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, C3H8, HF, HI, HBr, HCl, NO; and inert gases such as He, N2, Ar. These gases can also be used in mixtures. When etching a substrate using the pattern of the resist underlayer film as a mask, fluorine-based gases are usually used.

[0135] Method for forming a resist underlayer film The method for forming the resist underlayer film comprises a step of coating a resist underlayer film forming composition directly or indirectly onto a substrate. The resist underlayer film forming composition can preferably be one used in the semiconductor substrate manufacturing method described above. The coating step can preferably be one used in the semiconductor substrate manufacturing method described above.

[0136] Cleaning solution The cleaning solution contains [E] an organic acid. Furthermore, it is preferable that the cleaning solution contains an organic solvent. The cleaning solution may also contain water as a solvent other than the organic solvent. As such a cleaning solution, the cleaning solution used in the above-mentioned semiconductor substrate manufacturing method can be suitably adopted. [Examples]

[0137] The following describes some examples. It should be noted that the following examples are representative examples of the present invention and should not be interpreted as narrowing the scope of the invention.

[0138] In this example, the concentrations of components other than the solvent in the mixture containing compound [A], the weight-average molecular weight (Mw) of the hydrolysis condensate in the mixture containing compound [A], and the average film thickness were measured by the following method.

[0139] [[A] Concentration of components other than the solvent in a mixture containing the compound] The mass of the residue after calcining 0.5 g of a mixture containing compound [A] at 250°C for 30 minutes was measured, and the concentration (mass%) of components other than the solvent in the mixture containing compound [A] was calculated by dividing the mass of this residue by the mass of the mixture containing compound [A].

[0140] [Weight average molecular weight (Mw)] Analysis was performed using GPC columns (two "AWM-H", one "AW-H", and two "AW2500" columns from Tosoh Corporation), with a flow rate of 0.3 mL / min, elution solvent being N,N-dimethylacetamide with LiBr (30 mM) and citric acid (30 mM), and a column temperature of 40°C. The results were measured by gel permeation chromatography (detector: differential refractometer) with monodisperse polystyrene as the standard.

[0141] [Average thickness of the resist underlayer] The average thickness of the resist underlayer was determined by measuring the film thickness at nine arbitrary points spaced 5 cm apart, including the center of the resist underlayer, using a spectroscopic ellipsometer (JAWOOLLAM's "M2000D"), and then calculating the average of these film thicknesses.

[0142] <[A] Synthesis of Compounds> The compounds [m], [x], [d], and [B] used in the synthesis of compound [A] are shown below. In the following synthesis examples, unless otherwise specified, "parts by mass" refers to the value when the mass of compound [m] used is 100 parts by mass. Also, "molar ratio" refers to the value when the amount of substance of compound [m] used is 1. The concentrations (by mass) of components other than the solvent in the mixture containing compound [A] are also shown in Table 1. In Table 1 below, "-" indicates that the corresponding component was not used.

[0143] The following compounds were used as the [m] compound. m-1: Tetra-n-propoxydirconium(IV) m-2: Tetra-n-butoxyzirconium(IV) m-3: Tetra-n-propoxyhafnium(IV) m-4: Tetraisopropoxytitanium (IV) m-5: Pentaethoxitantalum (V) m-6: Tetraisopropoxytin(IV)

[0144] The following compounds were used as [x] compounds. x-1: Propionic acid x-2: Butyrate x-3: Isobutyric acid x-4: Methacrylic acid x-5:2-ethylhexanoic acid x-6: Acetylacetone x-7: Diethanolamine

[0145] [d] The following compounds were used as solvents. d-1: n-propyl alcohol d-2: Ethanol d-3: 1-butanol d-4: Isopropanol

[0146] [B] The following compounds were used as solvents. B-1: Propylene glycol monomethyl ether acetate B-2: Propylene glycol monoethyl ether

[0147] [Synthesis Example 1-1] (Synthesis of compound (A-1) [A]) Under a nitrogen atmosphere, compound (m-1) and solvent (d-1) (40 parts by mass) were added to a reaction vessel. Compound (x-1) (molar ratio 5) was added dropwise to the reaction vessel over 20 minutes while stirring at 50°C. The reaction was then carried out at 80°C for 3 hours. After the reaction was complete, the reaction vessel was cooled to below 30°C. The precipitate obtained by cooling was filtered off, washed with n-hexane (100 parts by mass), and then vacuum dried to obtain compound (A-1).

[0148] [Synthesis Example 1-2] (Synthesis of compound (A-2) [A]) Under a nitrogen atmosphere, compound (m-1) and solvent (d-1) (200 parts by mass) were added to a reaction vessel. Compound (x-2) (molar ratio 5) was added dropwise to the reaction vessel over 20 minutes while stirring at 50°C. The reaction was then carried out at 80°C for 3 hours. After the reaction was complete, the reaction vessel was cooled to below 30°C. After adding 900 parts by mass of solvent (B-1) to the cooled reaction solution, 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). [A] The concentration of components other than the solvent in the mixture containing compound (A-2) was 14% by mass.

[0149] [Synthesis Examples 1-10, 1-14] (Synthesis of compounds (A-10) and (A-14) of [A]) Compounds [A] (A-10) and (A-14) were obtained in the same manner as in Synthesis Example 1-1, except that the types and amounts of compound [m], compound [x], and solvent [d] shown in Table 1 below were used.

[0150] [Synthesis Examples 1-3 to 1-9, 1-11 to 1-13 and 1-17] (Synthesis of compounds (A-3) to (A-9), (A-11) to (A-13) and (A-17) of [A] compounds) A mixture containing compounds (A-3) to (A-9), (A-11) to (A-13), and (A-17) was obtained in the same manner as in Synthesis Example 1-2, except that the types and amounts of compound [m], compound [x], solvent [d], and solvent [B] shown in Table 1 below were used.

[0151] [Synthesis Example 1-15] (Synthesis of compound (A-15) [A]) Compound (m-4) was added to the reaction vessel under a nitrogen atmosphere. Compound (x-6) (molar ratio 2) was added dropwise over 30 minutes while stirring at room temperature (25°C to 30°C). The reaction was then carried out at 60°C for 2 hours. After the reaction was complete, the reaction vessel was cooled to below 30°C. The cooled reaction solution was diluted with solvent (d-4) (900 parts by mass). Water (molar ratio 2) was added dropwise over 10 minutes while stirring at room temperature (25°C to 30°C). The hydrolysis condensation reaction was then carried out at 60°C for 2 hours. After the hydrolysis condensation reaction was complete, the reaction vessel was cooled to below 30°C. After adding 1,000 parts by mass of solvent (B-2) to the cooled reaction solution, water, isopropanol, the alcohol produced by the reaction, water, and excess solvent (B-2) were removed using an evaporator to obtain a mixture containing compound (A-15). [A] The concentration of components other than the solvent in the mixture containing compound (A-15) was 13% by mass.

[0152] [Synthesis Example 1-16] (Synthesis of compound (A-16) [A]) A mixture containing compound [A] (A-16) was obtained in the same manner as in Synthesis Example 1-15, except that the types and amounts of compound [m], compound [x], solvent [d], and solvent [B] shown in Table 1 below were used.

[0153] [Table 1]

[0154] <Preparation of composition> The compounds [A], solvents [B], and other optional components [F] used in the preparation of the composition are shown below.

[0155] [A] The compounds (A-1) to (A-17) synthesized above were used as compounds.

[0156] [B] In addition to (B-1) and (B-2) used in the synthesis of [A] compound, the following compounds were used as solvents. B-3: Cyclohexanone B-4: Messicilen B-5: Butyl acetate B-6:2-Heptanon

[0157] [F] The following compounds were used as other optional components. F-1:4-Methoxyphenol

[0158] [Example 1-1] Preparation of composition (J-1) As shown in Table 2 below, 10 parts by mass of compound (A) (A-1) were mixed with 90 parts by mass of solvent (B) (B-3). 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 below, a "-" next to [F] other optional components indicates that [F] other optional components were not used. The same applies hereafter.

[0159] [Examples 1-2] Preparation of composition (J-2) As shown in Table 2 below, a mixture containing compound [A] (A-2) and solvent [B] (B-1) were mixed so that the amount of solvent [B] was 90 parts by mass (including the solvent [B] contained in the mixture containing compound [A]) for every 10 parts by mass of the non-solvent components in compound [A] (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).

[0160] [Examples 1-3 to 1-29] Preparation of compositions (J-3) to (J-29) Compositions (J-3) to (J-29) were prepared in the same manner as in Example 1-1 or Example 1-2, except that the types and contents of each component were as shown in Table 2 below. In Table 2 below, "-" indicates that the corresponding component was not used.

[0161] [Table 2]

[0162] <Preparation of cleaning solution> The following are the solvents other than the [E] organic acid, [G] organic solvent, and [G] organic solvent used in the preparation of the washing solution.

[0163] [E] The following compounds (E-1) to (E-10) were used as organic acids. E-1: Formic acid E-2: Acetic acid E-3: Propionic acid E-4: Acrylic acid E-5: Butyrate E-6: Isobutyric acid E-7: Methacrylic acid E-8: Crotonic acid E-9: 2-ethylhexanoic acid E-10: Oxalic acid

[0164] [G] The following compounds (G-1) to (G-4) and (G-6) to (G-7) were used as organic solvents, and (G-5) was used as a solvent other than organic solvents. G-1: Propylene glycol monomethyl ether acetate G-2: Butyl acetate G-3:2-Heptanon G-4: Propylene glycol monomethyl ether G-5: Water G-6: Dimethyl sulfoxide G-7: Sulfolane

[0165] [Example 2-1] Preparation of cleaning solution (K-1) As shown in Table 3 below, 80 parts by mass of [G] organic solvent (G-1) were mixed with 20 parts by mass of [E] organic acid (E-1). The resulting solution was filtered through a polytetrafluoroethylene (PTFE) filter with a pore size of 0.2 μm to prepare washing solution (K-1). In Table 3 below, "-" indicates that the corresponding component was not used.

[0166] [Examples 2-2 to 2-29 and Comparative Example 1-1] Preparation of washing solutions (K-2) to (K-29) and (k-1) Washing solutions (K-2) to (K-29) and (k-1) were prepared in the same manner as in Example 2-1, except that the types and contents of each component were as shown in Table 3 below.

[0167] [Table 3]

[0168] <Rating> The metal cleaning properties and drainage stability of each of the compositions prepared above were evaluated according to the following method. The evaluation results are shown in Tables 4-1 and 4-2 below.

[0169] [Metal cleaning ability] Each of the above-prepared compositions was coated onto a silicon wafer (substrate) using a spin coater (CLEAN TRACK ACT8 from Tokyo Electron Ltd.) by rotary coating. Then, while rotating the substrate at 1,500 rpm, the cleaning solution discharge nozzle was moved at a speed of 1 mm per second to a position 2 mm from the outer edge of the substrate to the center of the substrate, and the cleaning solution (K) was discharged at a discharge rate of 2 ml per second. After discharging the cleaning solution at a discharge rate of 2 ml per second for 10 seconds at this position 2 mm from the outer edge of the substrate to the center of the substrate, the substrate was rotated at 1,500 rpm for 30 seconds. Next, the substrate was heated at 450°C for 60 seconds to obtain evaluation substrate A with a resist underlayer film of average thickness 30 nm. The outermost surface of the periphery (front and back surfaces, 0.3 mm from the edge) of the obtained evaluation substrate A was exposed to acid, and the entire amount of the liquid obtained from the exposure was collected and used as the measurement solution. The amount of metal was then measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0170] Except for using cleaning solution (k-1) as the cleaning solution, evaluation substrate B with a resist underlayer film of average thickness 30 nm was obtained in the same procedure as for obtaining evaluation substrate A. The outermost surface of the outer periphery of the obtained evaluation substrate B (the front and back surfaces within 0.3 mm from the edge) was wetted with acid, and the entire amount of liquid obtained from the wetting process was collected and used as the test solution for measurement. The amount of metal was measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0171] Metal cleaning performance was evaluated as follows: if the amount of metal constituting the [A] compound detected from evaluation substrate A was less than 10% compared to evaluation substrate B, it was evaluated as "A"; if it was 10% or more but less than 50%, it was evaluated as "B"; and if it was 50% or more, it was evaluated as "C".

[0172] [Drainage stability] A mixed solution was prepared by mixing equal volumes of composition (J) and washing solution (K), and the presence or absence of precipitation and turbidity was visually checked after standing at 23°C and -15°C for one week. Drainage stability was evaluated as "A" if there was no precipitation or turbidity in the prepared mixed solution after standing at -15°C for one week, and as "B" if there was no precipitation or turbidity after standing at 23°C for one week, but precipitation or turbidity was observed after standing at -15°C for one week.

[0173] [Table 4-1]

[0174] [Table 4-2]

[0175] As can be seen from the results in Tables 4-1 and 4-2, the examples showed superior metal cleaning performance and drainage stability compared to the comparative examples. [Industrial applicability]

[0176] The semiconductor substrate manufacturing method of the present invention uses a cleaning solution with excellent cleaning properties and drainage stability to clean the peripheral area of ​​the substrate, thereby enabling the efficient production of high-quality semiconductor substrates. The resist underlayer film formation method of the present invention uses a cleaning solution with excellent cleaning properties and drainage stability, allowing for the efficient formation of a desired resist underlayer film. The cleaning solution of the present invention is excellent in both cleaning properties and drainage stability. Therefore, these can be suitably used in the manufacture of semiconductor devices, where further miniaturization is expected in the future.

Claims

1. A step of coating a resist underlayer film formation composition directly or indirectly onto a substrate, A cleaning solution used in a method for manufacturing a semiconductor substrate, which includes a step of cleaning the peripheral edge of the substrate with a cleaning solution, The above resist underlayer film forming composition, Metal compounds and, solvent and It contains, The above cleaning solution contains an unsaturated carboxylic acid as an organic acid, The above metal compound is a washing solution containing a metal atom belonging to Group 4, Group 5, or Group 14 of the periodic table, and a carboxylic acid, β-diketone, or amine compound.

2. The cleaning solution according to claim 1, wherein the cleaning solution contains an organic solvent.

3. The washing solution according to claim 2, wherein the organic solvent is at least one selected from the group consisting of ketone solvents and ester solvents.

4. The washing solution according to claim 1, wherein the unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, and 3-butenic acid.

5. The cleaning solution according to any one of claims 1 to 4, wherein the content of organic acids in the total components contained in the above cleaning solution is 3% by mass or more and 60% by mass or less.

6. A step of coating a substrate with a resist underlayer film formation composition, either directly or indirectly. The process involves cleaning the peripheral edge of the above substrate with a cleaning solution, After the above cleaning step, a step is made to directly or indirectly form a resist pattern on the resist underlayer film formed by the above coating step. Includes, The above resist underlayer film forming composition, Metal compounds and, solvent and It contains, The above cleaning solution contains an unsaturated carboxylic acid as an organic acid, The above-mentioned metal compound comprises a metal atom belonging to Group 4, Group 5, or Group 14 of the periodic table and a carboxylic acid, β-diketone, or amine compound, and is a method for producing a semiconductor substrate.

7. Prior to the above resist pattern formation step, The process of forming an organic underlayer film directly or indirectly on the resist underlayer film described above. A method for manufacturing a semiconductor substrate according to claim 6, further comprising:

8. Prior to the above resist pattern formation step, The process of forming a silicon-containing film directly or indirectly on the resist underlayer film described above. A method for manufacturing a semiconductor substrate according to claim 6, further comprising:

9. The method for manufacturing a semiconductor substrate according to claim 6, wherein the cleaning solution contains an organic solvent.

10. The method for producing a semiconductor substrate according to claim 9, wherein the organic solvent is at least one selected from the group consisting of ketone solvents and ester solvents.

11. The method for producing a semiconductor substrate according to claim 6, wherein the unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, and 3-butenic acid.

12. A method for manufacturing a semiconductor substrate according to any one of claims 6 to 11, wherein the content of organic acids in the total components contained in the above-mentioned cleaning solution is 3% by mass or more and 60% by mass or less.

13. A step of coating a resist underlayer film formation composition directly or indirectly onto a substrate, A step of cleaning the peripheral edge of the above substrate with a cleaning solution, Includes, The above resist underlayer film forming composition, Metal compounds and, solvent and It contains, The above cleaning solution contains an unsaturated carboxylic acid, The above-mentioned metal compound comprises a metal atom belonging to Group 4, Group 5, or Group 14 of the periodic table and a carboxylic acid, β-diketone, or amine compound, and is a method for forming a resist underlayer film.

Images