Liquid chemical, and method for producing semiconductor device

Abstract

The present invention addresses the problem of providing a liquid chemical which can etch a product obtained by modifying titanium nitride through dry etching and which is unlikely to cause galvanic corrosion when applied to a treatment object having a structure in which a region containing titanium nitride is joined to a region containing molybdenum or tungsten. This liquid chemical contains: an anti-corrosion agent; a fluoride ion source; an acid; an organic solvent selected from the group consisting of an alcohol, an ether, a sulfone, an amide and a sulfoxide; and water. The content of the anti-corrosion agent is 1 mass% or less relative to the total mass of the liquid chemical. The content of the organic solvent is 80 mass% or more relative to the total mass of the liquid chemical. The content of the water is 1-12 mass% relative to the total mass of the liquid chemical.

Description

Chemical solutions, semiconductor device manufacturing methods

[0001] The present invention relates to a chemical solution and a method for manufacturing a semiconductor device.

[0002] As semiconductor devices become increasingly miniaturized, there is an increasing demand for highly efficient and accurate etching, cleaning, and other processes using processing solutions during the semiconductor device manufacturing process. For example, although multiple materials may exist on a semiconductor substrate, it is desirable to be able to selectively remove only a specific material during etching.

[0003] As such an etching solution, for example, Patent Document 1 discloses an etching solution containing water, a phosphorus-containing inorganic acid, a fluoride ion source, and a water-miscible organic solvent.

[0004] Japanese Patent Application Laid-Open No. 2019-075546

[0005] Depending on the application, the chemical solution is required to have the ability to etch titanium nitride (TiN) dry-etched modified products. Furthermore, as a processing target used in the manufacture of semiconductor devices, a processing object in which a region containing TiN is bonded to a region containing molybdenum (Mo) or tungsten (W) may be used. When used on such processing objects, the chemical solution is also required to suppress the occurrence of galvanic corrosion. The inventors have studied the etching solution described in the above literature and found that it is difficult to achieve both of the above performances and that improvements are necessary.

[0006] Therefore, an object of the present invention is to provide a chemical solution that can etch TiN dry-etching modified products and that is less likely to cause galvanic corrosion when applied to a workpiece having a structure in which a region containing TiN is joined to a region containing Mo or W. Another object of the present invention is to provide a method for manufacturing a semiconductor device using the above chemical solution.

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0008] [1] A chemical solution comprising an inhibitor, a fluoride ion source, an acid, an organic solvent selected from the group consisting of alcohols, ethers, sulfones, amides, and sulfoxides, and water, wherein the content of the inhibitor is 1 mass% or less relative to the total mass of the chemical solution, the content of the organic solvent is 80 mass% or more relative to the total mass of the chemical solution, and the content of the water is 1 to 12 mass% relative to the total mass of the chemical solution. [2] The chemical solution according to [1], wherein the inhibitor contains at least one of an oxygen atom, a nitrogen atom, a phosphorus atom, and a sulfur atom. [3] The chemical solution according to [1] or [2], wherein the inhibitor contains an aromatic ring. [4] The chemical solution according to any one of [1] to [3], wherein the inhibitor contains an aromatic heterocycle. [5] The chemical solution according to any one of [1] to [4], wherein the inhibitor contains an acidic functional group. [6] The chemical solution according to any one of [1] to [5], wherein the anticorrosive agent contains a nitrogen atom. [7] The chemical solution according to any one of [1] to [6], wherein the anticorrosive agent is a compound represented by formula (1) described below. [8] The chemical solution according to any one of [1] to [7], wherein the fluoride ion source contains hydrofluoric acid. [9] The chemical solution according to any one of [1] to [8], wherein the content of the organic solvent is 90 mass% or more based on the total mass of the chemical solution.

[10] The chemical solution according to any one of [1] to [9], wherein the organic solvent is alcohol.

[11] The chemical solution according to any one of [1] to

[10] , wherein the content of the water is 1 to 5 mass% based on the total mass of the chemical solution.

[12] The chemical solution according to any one of [1] to

[11] , wherein the chemical solution is used for treating a substrate containing titanium atoms and molybdenum or tungsten.

[13] A method for manufacturing a semiconductor device, comprising a step of contacting a workpiece containing titanium nitride and molybdenum or tungsten with the chemical solution according to any one of [1] to

[12] .

[0009] According to the present invention, it is possible to provide a chemical solution that can etch a dry-etching modified product of TiN and that is less likely to cause galvanic corrosion when applied to a workpiece having a structure in which a region containing TiN is joined to a region containing Mo or W. Furthermore, according to the present invention, it is also possible to provide a method for manufacturing a semiconductor device using the above chemical solution.

[0010] 1 is a cross-sectional view showing an embodiment of an object to be treated with a chemical solution according to the present invention.

[0011] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in this specification, when two or more types of a certain component are present, the "content" of that component means the total content of those two or more components. In this specification, in a numerical range described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in a numerical range described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the Examples. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] In this specification, the bonding direction of a divalent group (e.g., -COO-) is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", the compound may be "X-O-CO-Z" or "X-CO-O-Z". In this specification, when there are multiple substituents and linking groups, etc. (hereinafter referred to as substituents, etc.) represented by specific symbols, or when multiple substituents, etc. are specified simultaneously, unless otherwise specified, this means that the respective substituents, etc. may be the same or different from each other. The same applies to the specification of the number of substituents, etc.

[0014] In this specification, "ppm" means "parts-per-million (10 －６ ) and "ppb" stands for "parts-per-billion (10 －９ In this specification, 1 Å (angstrom) corresponds to 0.1 nm.

[0015] In this specification, the pKa (acid dissociation constant) can be a value calculated in water (at 25°C) using, for example, Calculator Plugins (manufactured by Fujitsu Corporation). If measurement in water is not possible, a value calculated in dimethyl sulfoxide can be used. Unless otherwise specified, the ClogP (octanol / water partition coefficient) values ​​shown in this specification are values ​​calculated using ChemBioDraw Ultra (Version 16.0.14).

[0016] [Chemical Solution] The chemical solution of the present invention will be described in detail below. The chemical solution of the present invention (hereinafter also simply referred to as "chemical solution") is a chemical solution containing an anticorrosive agent, a fluoride ion source, an acid, an organic solvent selected from the group consisting of alcohols, ethers, sulfones, amides, and sulfoxides, and water, wherein the content of the anticorrosive agent is 1 mass % or less relative to the total mass of the chemical solution, the content of the organic solvent is 80 mass % or more relative to the total mass of the chemical solution, and the content of the water is 1 to 12 mass % relative to the total mass of the chemical solution.

[0017] Although the reason why the chemical solution having the above-described configuration can solve the problems of the present invention is not entirely clear, the inventors speculate as follows. The following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the one described below, it is still within the scope of the present invention. The chemical solution of the present invention contains a fluoride ion source and an acid that function as etchants, as well as water for dissolving them, in a predetermined amount or more, and the content of the corrosion inhibitor is specified to be a predetermined amount or less, thereby exhibiting excellent etching performance for dry-etching modified TiN (hereinafter simply referred to as "TiN modified product"). Here, galvanic corrosion generally occurs due to a corrosion potential difference between two adjacent regions. When the chemical solution of the present invention is brought into contact with a structure in which a region containing TiN is joined to a region containing Mo or W (hereinafter also referred to as "specific structure"), the corrosion inhibitor in the chemical solution interacts with the region containing Mo or W in the workpiece, thereby appropriately adjusting the corrosion potential. Furthermore, the chemical solution of the present invention contains a specific organic solvent through which corrosion current does not easily flow in a predetermined amount or more, and the content of water through which corrosion current easily flows is a predetermined amount or less, so that corrosion current does not easily flow. As a result, it is presumed that galvanic corrosion can be suppressed when the chemical solution of the present invention is applied to a workpiece having a specific structure. Hereinafter, the excellent etching performance of a dry-etching modified TiN product is simply referred to as "excellent etching performance," and the low occurrence of galvanic corrosion when applied to a workpiece having a specific structure is simply referred to as "ability to suppress galvanic corrosion." Furthermore, the achievement of at least one of better etching performance and better suppression of galvanic corrosion is simply referred to as "excellent effects of the present invention." Below, each component contained in the chemical solution is described in detail.

[0018] [Corrosion inhibitor] The chemical solution of the present invention contains a corrosion inhibitor. The corrosion inhibitor is a compound that can inhibit metal etching by interacting with a metal surface. Examples of the corrosion inhibitor include organic compounds containing heteroatoms. Examples of heteroatoms contained in the corrosion inhibitor include oxygen atoms, nitrogen atoms, phosphorus atoms, sulfur atoms, boron atoms, selenium atoms, and halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. In order to further inhibit galvanic corrosion, the corrosion inhibitor preferably contains at least one atom selected from the group consisting of oxygen atoms, nitrogen atoms, phosphorus atoms, sulfur atoms, and halogen atoms, more preferably at least one atom of oxygen atoms, nitrogen atoms, phosphorus atoms, and sulfur atoms, and even more preferably a nitrogen atom. The number of heteroatoms contained in the corrosion inhibitor is not particularly limited, and is preferably 1 or more, more preferably 2 or more, and even more preferably 2 to 10. The heteroatom may be contained as a part of a functional group (e.g., a hydroxyl group, a carboxylic acid group, an amino group, etc.), as a ring atom, or as a linking group (e.g., -O-, -CO-), and is preferably contained as at least one of a part of a functional group and a ring atom.

[0019] The corrosion inhibitor preferably has a heteroatom-containing functional group, since it can efficiently interact with Mo or W to further suppress galvanic corrosion. Examples of the heteroatom-containing functional group include an acidic functional group, a hydroxyl group, a mercapto group, an amino group, an imino group, a guanidino group, a biguanide group, a quaternary ammonium base, a pyridyl group, and a halogen atom. Acidic functional groups, amino groups, or quaternary ammonium bases are preferred, and acidic functional groups are more preferred. Examples of the acidic functional group include a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, and salts thereof. A carboxylic acid group or a salt thereof is preferred. Examples of the salt include metal salts such as alkali metal salts and alkaline earth metal salts, as well as ammonium salts. Examples of the quaternary ammonium base include -N ＋ R Ｎ ３ X － Examples of the group include a group represented by the following formula: ＮEach of X independently represents a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group include an alkyl group and an aryl group. Examples of the substituent that the hydrocarbon group may have include an alkyl group, an aryl group, a halogen atom, and a hydroxyl group. － represents a monovalent anion, and examples thereof include hydroxide ions, halide ions, and acid ions such as nitrate ions. When the corrosion inhibitor contains an acidic functional group, the pKa is preferably 1.0 or higher, more preferably 2.0 or higher, and even more preferably 2.5 or higher. There is no particular upper limit to the pKa of the corrosion inhibitor, and it is often 6.0 or lower. When the corrosion inhibitor contains an acidic functional group, the number of acidic functional groups is preferably 1 to 3, and more preferably 1.

[0020] The corrosion inhibitor preferably contains an aromatic ring, as this provides a more excellent effect of the present invention. The aromatic ring may be either a monocyclic or polycyclic ring. The number of ring atoms in the aromatic ring is preferably 4 to 20, more preferably 5 to 10, and even more preferably 6 to 10. The aromatic ring may be either an aromatic hydrocarbon ring or an aromatic heterocyclic ring, with an aromatic heterocyclic ring being preferred in terms of better suppression of galvanic corrosion. The heteroatom contained in the aromatic heterocyclic ring is not particularly limited, but is preferably an oxygen atom, a nitrogen atom, or a sulfur atom, and more preferably a nitrogen atom. That is, the corrosion inhibitor more preferably contains a nitrogen-containing aromatic heterocyclic ring. The nitrogen-containing aromatic heterocyclic ring may contain a heteroatom other than a nitrogen atom, but is also preferably free of such a heteroatom. The number of heteroatoms contained in the aromatic heterocyclic ring is preferably 1 to 5, more preferably 1 or 2, and even more preferably 1. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring, with a benzene ring being preferred. Examples of the aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a quinoline ring, a triazine ring, a quinoxaline ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, a triazole ring, a tetrazole ring, a benzopyrrole ring, a benzofuran ring, a benzothiophene ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a naphthopyrrole ring, a naphthofuran ring, a naphthothiophene ring, a naphthoimidazole ring, a naphthoxazole ring, a thienothiazole ring, and a porphyrin ring. A pyridine ring, a furan ring, a thiophene ring, a pyrrole ring, a quinoline ring, or a triazole ring is preferred, and a pyridine ring or a quinoline ring is more preferred.

[0021] Among these, the anticorrosive agent preferably contains an aromatic ring and an acidic functional group, and is more preferably a compound represented by formula (1). １ -Ar-(R ２ ) ｎ Formula (1)

[0022] In formula (1), Ar represents a nitrogen-containing aromatic heterocycle. The nitrogen-containing aromatic heterocycle may be either a monocycle or a polycycle. The number of ring atoms in the nitrogen-containing aromatic heterocycle is preferably 4 to 20, more preferably 5 to 10, and even more preferably 6 to 10. The number of nitrogen atoms contained in the nitrogen-containing aromatic heterocycle represented by Ar is 1 or more, preferably 1 to 3, and more preferably 1 or 2.

[0023] In formula (1), R １ represents a substituent containing an acidic functional group. The acidic functional group is as described above. The substituent containing an acidic functional group may be an acidic functional group or a group having an acidic functional group as part of the substituent, and is preferably an acidic functional group. Examples of the group having an acidic functional group as part of the substituent include -L-(X) ｍ L represents an (m+1) valent linking group, X represents an acidic functional group, and m represents an integer of 1 or more. The (m+1) valent linking group includes an (m+1) valent aliphatic hydrocarbon group. The (m+1) valent aliphatic hydrocarbon group includes one or more —CH ２ - is -O-, -CO-, -NR Ｎ - or -S-. Ｎ represents a hydrogen atom or a substituent. The number of carbon atoms in the (m+1)-valent aliphatic hydrocarbon group is preferably 1 to 10, and more preferably 1 to 6. m is preferably an integer of 1 to 3, and more preferably 1.

[0024] In formula (1), R ２ represents a substituent. ２ Examples of the substituent represented by the formula (I) include an acidic functional group, a hydroxyl group, a mercapto group, an amino group, an imino group, a guanidino group, an ammonium base, a halogen atom, an alkyl group which may have a substituent, an alkoxy group, an acyl group, an aryl group, and an acyloxy group, and an acidic functional group or an amino group is preferred. Examples of the substituent which the alkyl group may have include an acidic functional group, an amino group, a hydroxyl group, and a halogen atom. When n is 2 or more, a plurality of R ２ may be the same as or different from each other.

[0025] In formula (1), n ​​represents an integer of 0 or greater. n is preferably an integer of 0 to 6, more preferably an integer of 0 to 3, and even more preferably 0 or 1.

[0026] The compound represented by formula (1) is preferably a compound represented by formula (2) in that the effects of the present invention are more excellent.

[0027]

[0028] In formula (2), R ３ represents a substituent containing an acidic functional group. ３ The definition and preferred embodiments of the substituent containing an acidic functional group represented by R １ is the same as the substituent containing an acidic functional group represented by R ４ ~R ７ Each of the groups independently represents a hydrogen atom or a substituent. Examples of the substituent include R ２ Examples of the substituent represented by R include the groups exemplified above. ４ ~R ７ may be bonded to each other to form a ring which may have a substituent. The ring may be either an aromatic ring or a non-aromatic ring. The ring may also be either a hydrocarbon ring or a heterocyclic ring. The ring is preferably a monocyclic aromatic ring, more preferably a benzene ring or a pyridine ring. Examples of the substituent which the ring may have include R in formula (1). ２ Examples of the substituent represented by the formula (I) include the groups exemplified above.

[0029] The corrosion inhibitor may be a compound that does not contain an aromatic ring. Examples of corrosion inhibitors that do not contain an aromatic ring include non-aromatic corrosion inhibitors that have a functional group containing a heteroatom and an aliphatic hydrocarbon group having 3 or more carbon atoms. The aliphatic hydrocarbon group having 3 or more carbon atoms may be linear, branched, or cyclic. The aliphatic hydrocarbon group has 3 or more carbon atoms, preferably 3 to 20, more preferably 6 to 12, and even more preferably 8 to 12.

[0030] An example of the anticorrosive agent not containing an aromatic ring is a compound represented by formula (3): (X １１ )ｓ -R １１ Formula (3) In formula (3), X １１ R each independently represents a functional group containing a hetero atom. Examples of the functional group containing a hetero atom are as described above, and an acidic functional group, a hydroxyl group, a mercapto group, or an amino group is preferred, and an acidic functional group or an amino group is more preferred. １１ represents an s-valent aliphatic hydrocarbon group having 3 or more carbon atoms. The number of carbon atoms in the aliphatic hydrocarbon group is 3 or more, preferably 6 or more, and more preferably 8 or more. The upper limit is preferably 20 or less, more preferably 12 or less. In particular, at least one X １１ is a hydroxyl group, R １１ is preferably an aliphatic hydrocarbon group having 6 or more carbon atoms, and more preferably an aliphatic hydrocarbon group having 8 or more carbon atoms. s represents an integer of 1 or more, preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and even more preferably 1.

[0031] Examples of the anticorrosive agent containing an aromatic ring include benzotrifluoride, chlorobenzene, aniline, benzethonium chloride, pyridine, 2-furancarboxylic acid, 2-thiophenecarboxylic acid, pyrrole-3-carboxylic acid, 5-quinolinecarboxylic acid, 8-quinolinecarboxylic acid, 3-amino-1,2,4-triazole-5-carboxylic acid, pyridine-2-sulfonic acid, 2,6-pyridinedicarboxylic acid, pyridine-2-carboxylic acid, 2-quinolinecarboxylic acid, 4-imidazolecarboxylic acid, 5-aminotetrazole, and benzoguanamine. -thiophenecarboxylic acid, pyrrole-3-carboxylic acid, 5-quinolinecarboxylic acid, 8-quinolinecarboxylic acid, 3-amino-1,2,4-triazole-5-carboxylic acid, pyridine-2-sulfonic acid, 2,6-pyridinedicarboxylic acid, pyridine-2-carboxylic acid, or 2-quinolinecarboxylic acid is preferred, 3-amino-1,2,4-triazole-5-carboxylic acid, pyridine-2-sulfonic acid, 2,6-pyridinedicarboxylic acid, pyridine-2-carboxylic acid, or 2-quinolinecarboxylic acid is more preferred, and pyridine-2-carboxylic acid or 2-quinolinecarboxylic acid is even more preferred. Examples of anticorrosive agents that do not contain an aromatic ring include L(+)-arginine, L-leucine, 6-mercapto-1-hexanol, 1-thioglycerol, heptylphosphonic acid, octylamine, 1-octanol, octanoic acid, and alexidine dihydrochloride, of which L-leucine, 6-mercapto-1-hexanol, 1-thioglycerol, heptylphosphonic acid, octylamine, 1-octanol, and octanoic acid are preferred, and L-leucine, heptylphosphonic acid, octylamine, and octanoic acid are more preferred.

[0032] The anticorrosive agent is preferably a low molecular weight compound. Specifically, the molecular weight of the anticorrosive agent is preferably 2000 or less, more preferably 1000 or less, and even more preferably 400 or less. There is no particular lower limit, but it is often 60 or more.

[0033] The anticorrosive agent may be used alone or in combination of two or more. The content of the anticorrosive agent is 1 mass% or less relative to the total mass of the chemical solution. If the content of the anticorrosive agent exceeds 1 mass% relative to the total mass of the chemical solution, the TiN modified substance is protected, which is not preferable, as the etching performance is deteriorated. The content of the anticorrosive agent is preferably 0.5 mass% or less relative to the total mass of the chemical solution, as this provides better etching performance. Furthermore, the content of the anticorrosive agent is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, relative to the total mass of the chemical solution, as this provides better effects of the present invention.

[0034] [Fluoride Ion Source] The chemical solution of the present invention contains a fluoride ion source. The fluoride ion source is a fluoride ion source that generates fluoride ions (F － ) or a compound capable of releasing a fluoride ion source. The fluoride ion source may be in the form of a fluoride ion or a fluorine-containing ion. Examples of fluorine-containing ions include bifluoride ions (HF ２ － ), SiF ６ ２－ , TiF ６ ２－ , ZrF ６ ２－ , P.F. ６ － , and BF ４ － The fluoride ion source is often a salt of a fluoride ion or a fluorine-containing ion with a cation. Preferred cations contained in the fluoride ion source include H ＋ , Li ＋ , Na ＋ , K. ＋ , and NH ４ ＋ are mentioned, and H ＋ is preferred.

[0035] Examples of fluoride ion sources include hydrofluoric acid (HF) and ammonium fluoride (NH ４ F), hexafluorosilicic acid and its salts (H ２ SiF ６ , Na ２ SiF ６ etc.), fluoroboric acid and its salts (HBF４ , K.B.F. ４ , N.H. ４ BF ４ etc.), hexafluorotitanic acid and its salts (H ２ TiF ６ etc.), hexafluorozirconic acid and its salts (H ２ ZrF ６ etc.), and hexafluorophosphate and its salts (HPF ６ Among them, hydrofluoric acid or ammonium fluoride is preferred, and hydrofluoric acid is more preferred, in terms of superior etching performance.

[0036] The fluoride ion source may be used alone or in combination of two or more. The content of the fluoride ion source is preferably 0.01 to 10 mass%, more preferably 1 to 5 mass%, relative to the total mass of the chemical solution, in terms of more excellent effects of the present invention. A solution containing a fluoride ion source may be used as the fluoride ion source. When a solution containing a fluoride ion source is used as the fluoride ion source, the content of the fluoride ion source is the content of the fluoride ion source contained in the solution.

[0037] [Acid] The chemical solution of the present invention contains an acid. The acid is a compound different from the above-mentioned corrosion inhibitor and fluoride ion source. Examples of the acid include inorganic acids and organic acids, with inorganic acids being preferred. Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, hydrobromic acid, boric acid, phosphonic acid, and phosphoric acid, with hydrochloric acid being preferred. The organic acid has one or more carbon atoms, preferably one or two, and more preferably one. Examples of organic acids include lower aliphatic sulfonic acids such as methanesulfonic acid and trifluoromethanesulfonic acid, lower aliphatic monocarboxylic acids such as formic acid and acetic acid, and salts thereof, with methanesulfonic acid being preferred.

[0038] The pKa of the acid is preferably 2.5 or less, more preferably 1.0 or less, even more preferably 0.0 or less, and particularly preferably -2.5 or less. There is no particular lower limit, and it is often -5.0 or more.

[0039] The acid may be used alone or in combination of two or more. The content of the acid is preferably 0.01 to 10 mass %, more preferably 0.1 to 3 mass %, and even more preferably 0.1 to 0.5 mass %, based on the total mass of the chemical solution.

[0040] [Organic Solvent] The chemical solution of the present invention contains an organic solvent selected from the group consisting of alcohols, ethers, sulfones, amides, and sulfoxides. The organic solvent is a compound different from the above-mentioned corrosion inhibitors and acids. The ClogP value of the organic solvent is preferably −0.3 to 1.6, more preferably −0.2 to 1.0, and even more preferably 0.0 to 0.8.

[0041] The number of carbon atoms in the alcohol is preferably 10 or less, more preferably 7 or less. The lower limit is 1 or more, preferably 3 or more. The alcohol may have a functional group other than a hydroxyl group, but it is also preferable that it does not have one. The alcohol may have an ether bond (-O-), but it is preferable that it has an ether bond. The alcohol may have a carbonyl bond (-CO-), but it is preferable that it does not have one. Among them, the alcohol is preferably an alcohol having R Ａ１ Solvent represented by —OH or R Ａ２ -O-R Ａ３ Solvents represented by —OH are preferred, and R Ａ２ -O-R Ａ３ Solvents represented by —OH are more preferred. Ａ１ and R Ａ２ R each independently represents a chain alkyl group which may have a phenyl group or a hydroxyl group. Ａ１ R is preferably a chain alkyl group having 1 to 7 carbon atoms which may have a hydroxyl group, and more preferably a chain alkyl group having 1 to 5 carbon atoms. Ａ２ As R, a chain alkyl group having 1 to 5 carbon atoms which may have a phenyl group is preferred. Ａ３represents a chain alkylene group, preferably a chain alkylene group having 1 to 6 carbon atoms, more preferably a chain alkylene group having 2 to 5 carbon atoms. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, cyclohexanediol, 2-methyl-2,4-pentanediol, 1,3-butanediol, 1,4-butanediol, 2-butoxyethanol, 3-methoxy-3-methyl-1-butanol, 1-butoxy-2-propanol, 2-(benzyloxy)ethanol, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, Examples of the alkylene glycol monoalkyl ether include ethylene glycol and alkylene glycol monoalkyl ethers (for example, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, and diethylene glycol monobutyl ether), and 1-butoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, 2-butoxyethanol, or 2-(benzyloxy)ethanol is preferred.

[0042] Ethers are solvents different from the alcohols and do not have a hydroxyl group. The number of carbon atoms in the ether is preferably 3 to 16, and more preferably 4 to 14. The ether may have a carbonyl bond (—CO—), but preferably does not have one. However, when the ether has a carbonyl bond, the carbonyl bond is not adjacent to the ether bond. Examples of ethers include diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, cyclohexyl methyl ether, tetrahydrofuran (THF), 4-methoxy-4-methyl-2-pentanone, and alkylene glycol dialkyl ethers (diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether).

[0043] Sulfones include, for example, sulfolane.

[0044] Examples of amides include formamide, monomethylformamide, dimethylformamide (DMF), acetamide, monomethylacetamide, dimethylacetamide, monoethylacetamide, diethylacetamide, and N-methylpyrrolidone.

[0045] Sulfoxides include, for example, dimethyl sulfoxide (DMSO).

[0046] The organic solvent is preferably an alcohol, a sulfone, an amide, or a sulfoxide, and more preferably an alcohol, in terms of achieving the effects of the present invention.

[0047] The organic solvent may be used alone or in combination of two or more. The content of the organic solvent is 80% by mass or more relative to the total mass of the chemical solution. If the content of the organic solvent is less than 80% by mass relative to the total mass of the chemical solution, it is not preferable because a corrosion current tends to flow and galvanic corrosion tends to occur. The content of the organic solvent is preferably 90% by mass or more relative to the total mass of the chemical solution, since the effects of the present invention are more excellent. The content of the organic solvent is less than 99% by mass relative to the total mass of the chemical solution, preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0048] [Water] The chemical solution of the present invention contains water. The type of water used in the chemical solution may be any type that does not adversely affect the semiconductor substrate, and distilled water, deionized water (DI (De Ionized) water), pure water, or ultrapure water is preferred. Pure water or ultrapure water is more preferred because it contains almost no impurities and has less of an effect on the semiconductor substrate in the semiconductor substrate manufacturing process.

[0049] The water content is 1 to 12 mass% relative to the total mass of the chemical solution. If the water content is less than 1 mass% relative to the total mass of the chemical solution, the fluoride ion source and the acid will not be able to exert their desired effects, resulting in poor etching performance, which is undesirable. If the water content is more than 12 mass%, a corrosion current will easily flow, which is undesirable, resulting in galvanic corrosion. The water content is preferably 1 to 7 mass%, more preferably 1 to 5 mass%, and even more preferably 3.5 to 5 mass%, relative to the total mass of the chemical solution.

[0050] [Other Components] The chemical solution of the present invention may contain other components in addition to those described above. Examples of other components include a basic compound, a surfactant, and an antifoaming agent.

[0051] (Basic Compound) The chemical solution of the present invention may contain a basic compound. A basic compound is a compound that exhibits alkaline (pH greater than 7.0) in an aqueous solution. Examples of basic compounds include inorganic bases. Examples of inorganic bases include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides, and ammonia or salts thereof. The content of the basic compound is preferably 0.1 to 20 mass %, more preferably 0.5 to 10 mass %, based on the total mass of the chemical solution.

[0052] (Surfactant) The chemical solution may contain a surfactant. Examples of surfactants include compounds having a hydrophilic group and a hydrophobic group (lipophilic group) in one molecule, such as anionic surfactants, cationic surfactants, and nonionic surfactants. However, the surfactant is a compound different from the above-mentioned components.

[0053] The surfactant content is not particularly limited, but is preferably 10 ppm by mass or more, more preferably 30 ppm by mass or more, relative to the total mass of the chemical solution. The upper limit is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, relative to the total mass of the chemical solution, from the viewpoint of suppressing foaming of the chemical solution.

[0054] (Antifoaming Agent) The chemical solution may contain an antifoaming agent. Surfactants may cause foaming depending on how they are used. Therefore, it is preferable that a chemical solution containing a surfactant contains an antifoaming agent that suppresses the generation of foam, shortens the lifespan of the generated foam, and suppresses residual foam. The antifoaming agent is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof include silicone-based antifoaming agents, acetylene diol-based antifoaming agents, fatty acid ester-based antifoaming agents, and long-chain aliphatic alcohol-based antifoaming agents. Among these, silicone-based antifoaming agents are preferred because of their superior effect of suppressing residual foam. It should be noted that the antifoaming agent does not include compounds contained in the above-mentioned surfactants.

[0055] [Physical properties of chemical solution] <pH> The pH of the chemical solution is preferably 0.5 to 6, more preferably 1 to 4. The pH of the chemical solution can be measured using a known pH meter by a method in accordance with JIS Z8802-1984. The measurement temperature is 25°C.

[0056] <Metal Content> The content (measured as ion concentration) of metals (e.g., metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the chemical solution is preferably 5 mass ppm or less, more preferably 1 mass ppm or less. In particular, the metal content is more preferably a value lower than 1 mass ppm, that is, a mass ppb order or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0057] <Insoluble Particles> The drug solution of the present invention preferably does not substantially contain insoluble particles. The term "insoluble particles" refers to particles of inorganic solids or organic solids that do not dissolve in the drug solution and ultimately exist as particles. The term "substantially does not contain insoluble particles" refers to a measurement composition obtained by diluting the drug solution 10,000 times with a solvent contained in the drug solution, and the number of particles with a particle size of 50 nm or more contained in 1 mL of the measurement composition is 40,000 or less. The number of particles contained in the measurement composition can be measured in the liquid phase using a commercially available particle counter. Commercially available particle counters include those manufactured by Rion and PMS. A representative example of the former is the KS-19F, and a representative example of the latter is the Chem20. To measure larger particles, devices such as the KS-42 series and LiQuilaz II S series can be used. Examples of insoluble particles include particles of inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and particles of organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. Methods for removing insoluble particles from the chemical solution include, for example, purification treatments such as filtering.

[0058] <Coarse particles> The chemical solution may contain coarse particles, but the content thereof is preferably low. Coarse particles refer to particles having a diameter (particle size) of 1 μm or more when the particle shape is considered to be a sphere. The coarse particles contained in the chemical solution include particles such as dust, dirt, organic solids, and inorganic solids contained as impurities in the raw material, as well as particles such as dust, dirt, organic solids, and inorganic solids brought in as contaminants during the preparation of the chemical solution, and which ultimately exist as particles without dissolving in the chemical solution.

[0059] The content of coarse particles in the chemical solution is preferably 100 or less, more preferably 50 or less, particles with a particle size of 1 μm or more per mL of the chemical solution. The lower limit is preferably 0 or more, more preferably 0.01 or more, per mL of the chemical solution. The content of coarse particles present in the chemical solution can be measured in the liquid phase using a commercially available measuring device that uses a light scattering liquid particle measuring method with a laser as a light source.

[0060] [Method for Producing the Chemical Solution] The chemical solution of the present invention can be produced by a known method. Hereinafter, the method for producing the chemical solution of the present invention will be described in detail.

[0061] [Solution Preparation Step] Examples of methods for preparing the chemical solution of the present invention include a method of mixing the above-mentioned components. The order and / or timing of mixing the above-mentioned components are not particularly limited, and examples include a method of sequentially adding an anticorrosive agent, a fluoride ion source, water, and, if necessary, optional components to a container containing an organic solvent, and then stirring to mix. Alternatively, the solution may be prepared by adjusting the pH of the mixed solution by adding a pH adjuster. Furthermore, when adding the components to a container, they may be added all at once or may be added in multiple divided portions.

[0062] The stirring device and stirring method used to prepare the chemical solution may be a known device such as a stirrer or disperser. Examples of the stirrer include an industrial mixer, a portable stirrer, a mechanical stirrer, and a magnetic stirrer. Examples of the disperser include an industrial disperser, a homogenizer, an ultrasonic disperser, and a bead mill.

[0063] <Purification> It is preferable to perform a purification treatment in advance on one or more of the raw materials used to prepare the chemical solution. Furthermore, if necessary, the chemical solution may also be subjected to a purification treatment. The degree of purification is preferably such that the raw material has a purity of 99% by mass or more, and more preferably such that the purity of the raw solution has a purity of 99.9% by mass or more. The upper limit is preferably 99.9999% by mass or less.

[0064] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO membrane), reprecipitation, distillation of the raw material, and filtering. A combination of the above purification methods may be used as the purification method. Furthermore, the purification method may be performed multiple times.

[0065] <Container> The chemical solution (including the diluted chemical solution described below) can be filled into any container for storage, transportation, and use, as long as corrosiveness and other factors do not pose a problem.

[0066] As a container, a container with a high degree of cleanliness within the container for semiconductor applications and that suppresses the elution of impurities from the inner wall of the container's storage section into the chemical solution is preferred. Examples of such containers include various containers commercially available as containers for semiconductor chemical solutions, such as the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd., but are not limited to these. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of International Publication No. 2022 / 004217 can also be used as containers, and the contents of these containers are incorporated herein.

[0067] The interior of these containers is preferably washed before filling with the chemical solution. The liquid used for washing is preferably one that has a reduced amount of metal impurities. After production, the chemical solution may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored.

[0068] To prevent changes in the components of the drug solution during storage, the inside of the container may be purged with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. A gas with a low moisture content is particularly preferred. During transportation and storage, the drug solution may be stored at room temperature, or the temperature may be controlled within the range of -20°C to 20°C to prevent deterioration.

[0069] [Dilution step] The above-mentioned chemical solution may be subjected to a dilution step in which the chemical solution is diluted with a diluent, and then used as a diluted chemical solution (diluted chemical solution). Note that the diluted chemical solution is also one form of the chemical solution of the present invention as long as it satisfies the requirements of the present invention. The specific method of the dilution step in which the chemical solution is diluted may be performed in accordance with the above-mentioned chemical solution preparation step. The stirring device and stirring method used in the dilution step may also be performed using the known stirring device mentioned in the above-mentioned chemical solution preparation step.

[0070] The method for producing the chemical solution may further include a static elimination step of eliminating static electricity from the chemical solution.

[0071] [Uses of Chemical Solution] The chemical solution of the present invention is preferably used for treating semiconductor substrates, more specifically, for semiconductor devices. "For semiconductor devices" means that it is used during the manufacture of semiconductor devices. The chemical solution can be used in the manufacturing process of semiconductor devices, and can be used to treat, for example, metal layers, insulating films, resist films, anti-reflective films, etching residues, and ashing residues (hereinafter simply referred to as "residues") present on a substrate. The chemical solution may also be used to treat semiconductor substrates after chemical mechanical polishing. The chemical solution of the present invention can be suitably used as an etching solution for removing dry-etched TiN alterations.

[0072] [Subject to be treated] The subject to be treated with the semiconductor chemical solution is not particularly limited as long as it is a component used in the manufacturing process of a semiconductor device, and examples thereof include semiconductor substrates. Semiconductor substrates containing metal inclusions are preferred, and semiconductor substrates having metal inclusions on the substrate are more preferred. The subject to be treated may contain multiple types of metal inclusions. In the present invention, "on the substrate" includes any of the front and back surfaces, side surfaces, and grooves of the substrate. Furthermore, "disposed on the substrate" includes both cases where the substrate is directly disposed on the surface of the substrate and cases where the substrate is disposed via another layer. The metal inclusions may be disposed on only one major surface of the substrate, or on both major surfaces. Furthermore, the metal inclusions may be disposed over the entire major surface of the substrate, or may be disposed over a portion of the major surface of the substrate. The form of the metal inclusions is not particularly limited, and may be, for example, a film-like form (metal film) or a particulate form (metal particles). The metal film may be planar or may be in the form of a wiring (wiring film).

[0073] A metal inclusion is a material containing a simple metal (metal atom) as a main component. Examples of the metal contained in the metal inclusion include at least one metal M selected from the group consisting of Mo (molybdenum), W (tungsten), Ti (titanium), Co (cobalt), Cu (copper), Ta (tantalum), Ru (ruthenium), Cr (chromium), Hf (hafnium), Os (osmium), Pt (platinum), Ni (nickel), Mn (manganese), Zr (zirconium), La (lanthanum), and Ir (iridium). The metal inclusion may be any substance containing a metal (metal atom), and examples thereof include at least one substance selected from the group consisting of a simple metal M, an alloy containing the metal M, an oxide of the metal M, a nitride of the metal M, an oxynitride of the metal M, a carbide of the metal M, and a halide of the metal M.

[0074] The workpiece preferably contains a titanium atom-containing material. In other words, the workpiece is preferably a substrate containing titanium atoms. The titanium atoms may be contained in any of the following forms: a simple substance, an alloy with another metal, or a complex with an atom other than a metal. Examples of the atoms other than metals include oxygen atoms, nitrogen atoms, carbon atoms, and halogen atoms, and examples of complexes with these atoms include nitrides, oxides, oxynitrides, carbides, and halides. Since the chemical solution of the present invention can be suitably used as an etching solution for TiN-modified materials, the workpiece preferably contains a TiN-modified material. Examples of TiN-modified materials include titanium oxide (TiO ｘ (where x represents 1 or 2), titanium halides, and titanium carbide. In addition, since the chemical solution of the present invention suppresses galvanic corrosion of a specific structure, it is also preferable that the object to be treated contains TiN. In particular, it is more preferable that the object to be treated contains titanium atoms as a TiN-modified product and TiN. When the object to be treated contains a TiN-modified product and TiN, the TiN-modified product and TiN may or may not be adjacent to each other.

[0075] The workpiece preferably includes a metal-containing material containing a metal other than titanium. The metal other than titanium is preferably Mo, W, Co, Cu, or Ru, with Mo or W being more preferred. That is, the workpiece preferably includes Mo or W. The Mo and W contained in the workpiece may each be a single metal, an alloy with another metal, or an oxide, with a single metal or oxide being preferred, and a single metal being more preferred. Examples of the other metal include Cu (copper), Co (cobalt), Ru (ruthenium), Al (aluminum), Ta (tantalum), Rh (rhodium), Cr (chromium), Hf (hafnium), Os (osmium), Pt (platinum), Ni (nickel), Mn (manganese), Zr (zirconium), La (lanthanum), and Ir (iridium). The workpiece may also be an alloy of Mo and W. When Mo or W is in the form of an alloy, the content of Mo or W is preferably 50 mass % or more, more preferably 80 mass % or more, based on the total mass of the alloy.

[0076] Among these, the workpiece is preferably a workpiece containing titanium atoms and Mo or W, more preferably a workpiece containing TiN and Mo or W, and even more preferably a workpiece containing a modified TiN, TiN, and Mo or W. Since the chemical solution of the present invention inhibits galvanic corrosion when contacted with a specific structure in which a region containing TiN and a region containing Mo or W are bonded, it is more preferable that the workpiece have the specific structure. The TiN-containing region may contain TiN, and is preferably a region substantially consisting of TiN (TiN layer). "Substantially consisting of TiN" means that the TiN content is 95% by mass or more relative to the total mass of the material, preferably 99 to 100% by mass. The Mo or W-containing region may contain at least one of Mo and W, and examples of the metal include a region consisting of a metal-containing material containing Mo or W as the metal. The chemical solution of the present invention may also be applied to workpieces that do not have a specific structure.

[0077] An example of the form of the workpiece having a specific structure is a laminate 100 having a substrate 10, a metal layer 20 containing Mo or W, a TiN layer 40, and a TiN modified substance 60 present on the substrate 10, as shown in FIG. 1 . As shown in FIG. 1 , the metal layer 20 containing Mo or W and the TiN layer 40 are bonded together. The chemical solution of the present invention can be suitably used to remove the TiN modified substance 60 from the laminate 100 shown in FIG. 1 . The form of the TiN modified substance 60 is not particularly limited, and may be, for example, in the form of a film or particles, as shown in FIG. 1 . Note that while FIG. 1 shows an embodiment in which the metal layer 20 and the TiN layer 40 are directly disposed on the substrate 10, they may be disposed via another layer. Furthermore, while FIG. 1 shows an embodiment in which the workpiece 100 includes a plurality of metal layers 20 and TiN layers 40, at least one of the metal layer 20 and the TiN layer 40 may be present in a single layer. Although FIG. 1 shows an embodiment in which the TiN modified material 60 is disposed on the TiN layer 40, the TiN modified material 60 may be disposed on the side of the TiN layer or may be disposed via another layer.

[0078] The workpiece is preferably one used for manufacturing a semiconductor device. That is, the chemical solution of the present invention is preferably used in a process for manufacturing a semiconductor device. As an element obtained by applying the chemical solution to the workpiece, a field effect transistor (FET) is preferred, and a gate-all-around-FET (GAA-FET) is more preferred. That is, the workpiece is preferably one obtained during the manufacturing process of a GAA-FET. Furthermore, the chemical solution of the present invention can also be used in a process for manufacturing a semiconductor device. For example, the workpiece may include an insulating film, a resist film, an anti-reflective film, etching residues, ashing residues, etc. present on a substrate. Furthermore, the workpiece may be a substrate after chemical mechanical polishing.

[0079] The substrate is not particularly limited, and examples thereof include metal substrates, semiconductor substrates, conductive substrates other than metal, metal oxide substrates, glass substrates, and resin substrates. Among these, semiconductor substrates are preferred. Examples of semiconductor substrates include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. Examples of materials constituting semiconductor substrates include silicon, germanium, and III-V group compounds such as GaAs, as well as combinations thereof.

[0080] In addition to the components described above, the workpiece may include other layers and / or structures as desired. For example, the substrate may have disposed thereon one or more members selected from the group consisting of metal wiring, gate electrodes, source electrodes, drain electrodes, insulating layers, ferromagnetic layers, and non-magnetic layers. The substrate may also include an exposed integrated circuit structure. The integrated circuit structure may include, for example, interconnect mechanisms such as metal wiring and dielectric materials. Examples of metals and alloys used in the interconnect mechanisms include aluminum, copper-aluminum alloys, copper, nickel, nickel silicide, cobalt, cobalt silicide, ruthenium, platinum, gold, titanium, tantalum, and tantalum nitride. The substrate may also include one or more layers of a material selected from the group consisting of silicon oxide, silicon nitride, silicon carbide, silicon, silicon germanium, and carbon-doped silicon oxide.

[0081] The method for manufacturing the workpiece is not particularly limited as long as it is a method commonly used in this field. For example, methods for forming a TiN film on a substrate include sputtering, chemical vapor deposition (CVD), and molecular beam epitaxy (MBE). Examples of methods for forming the metal layer on a substrate include forming a circuit using a known method such as resist, and then forming a metal layer using plating, sputtering, CVD, and molecular beam epitaxy (MBE). Examples of methods for forming a TiN modified material include performing a dry etching process using a known method on the TiN film formed by the above method.

[0082] Examples of applications of elements obtained by processing the workpiece include DRAM (Dynamic Random Access Memory), FRAM (registered trademark) (Ferroelectric Random Access Memory), MRAM (Magnetoresistive Random Access Memory), PRAM (Phase change Random Access Memory), logic circuits, and processors.

[0083] [Method for manufacturing a semiconductor device] A method for manufacturing a semiconductor device on a workpiece using the chemical solution of the present invention includes a treatment step of contacting the workpiece with the chemical solution of the present invention. By contacting the workpiece with the chemical solution of the present invention, TiN-modified products are selectively removed (etched). Note that during the treatment, a portion of at least one element selected from the group consisting of W, Mo, and TiN contained in the workpiece may be intentionally or unavoidably removed.

[0084] Methods for contacting the workpiece with the chemical solution include, for example, immersing the workpiece in the chemical solution contained in a tank, spraying the chemical solution onto the workpiece, flowing the chemical solution over the workpiece, and combinations of these methods, and the method of immersing the workpiece in the chemical solution is preferred.

[0085] Furthermore, in order to further increase the treatment speed with the chemical solution, a mechanical stirring method may be used, such as a method of circulating the chemical solution above the workpiece, a method of passing or spraying the chemical solution above the workpiece, or a method of stirring the chemical solution by ultrasonic waves or megasonics.

[0086] The treatment time using the chemical solution can be adjusted as appropriate. The treatment time (contact time between the chemical solution and the object to be treated) is preferably 0.5 to 60 minutes, more preferably 1 to 20 minutes. The temperature of the chemical solution during treatment is preferably 10 to 100°C, more preferably 15 to 60°C.

[0087] The method for manufacturing a semiconductor device may, if necessary, include a rinsing step in which the workpiece is rinsed with a rinse liquid after the above-mentioned treatment step. Examples of rinse liquids include water (preferably deionized (DI) water), methanol, ethanol, isopropanol, N-methylpyrrolidinone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. The organic solvent contained in the chemical solution of the present invention may also be suitably used.

[0088] The rinse treatment may be carried out by contacting the workpiece with a rinse liquid. The above-mentioned method of contacting the workpiece with a chemical liquid may also be applied to the rinse treatment.

[0089] The rinsing step may be followed by a drying step, if necessary. The drying method is not particularly limited, and examples thereof include spin drying, flowing a dry gas over the substrate, heating the substrate with a heating means such as a hot plate or an infrared lamp, IPA (isopropyl alcohol) vapor drying, Marangoni drying, Rotagoni drying, and combinations thereof.

[0090] The above-described treatment method may be performed before or after other processes performed on a substrate in the semiconductor device manufacturing process. The above-described cleaning method may be incorporated into other processes, or the above-described treatment method may be incorporated into other processes. Examples of other processes include processes for forming one or more structures selected from the group consisting of metal wiring, gate structures, source structures, drain structures, insulating layers, ferromagnetic layers, and nonmagnetic layers (e.g., layer formation, etching, chemical mechanical polishing, and modification), resist formation, exposure and removal processes, heat treatment processes, cleaning processes, and inspection processes. The treatment method for a workpiece using a chemical solution may be performed at any stage of the back-end process (BEOL), middle process (MOL), or front-end process (FEOL), and is preferably performed during the front-end process or middle process.

[0091] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0092] Preparation of Chemical Solutions Chemical solutions of the Examples or Comparative Examples were prepared by mixing the ingredients in a beaker with a 1-inch Teflon-coated stir bar. The first ingredient added to the beaker was the organic solvent, followed by the other ingredients in no particular order. Hydrofluoric acid was added immediately before use.

[0093] The pKa of the acids in the components shown in the table below is as follows: Hydrochloric acid (hydrogen chloride) pKa: -4 Phosphoric acid pKa: 2.1 Methanesulfonic acid pKa: -1.9

[0094] [Evaluation] The etching performance and galvanic corrosion suppression performance of the dry-etching modified TiN were evaluated according to the following procedures.

[0095] [Etching Performance of Dry Etching Modified TiN] A TiN wafer was prepared and etched using a dry etcher (Centura, manufactured by Applied Materials, Inc.). ２ A dry-etched modified TiN product was prepared by dry etching using a mixture of 10 ...

[0096] 5: 20 Å / min or more 4: 15 Å / min or more and less than 20 Å / min 3: 10 Å / min or more and less than 15 Å / min 2: 5 Å / min or more and less than 10 Å / min 1: Less than 5 Å / min

[0097] [Galvanic corrosion] A W wafer, a Mo wafer, and a TiN wafer were prepared and immersed in each chemical solution as measurement electrodes. The corrosion potential was determined based on a Tafel plot obtained using VersaSTAT4 (Model-400, manufactured by AMETEK Corporation, counter electrode: platinum electrode, reference electrode: Ag / AgCl glass electrode). The electromotive force of galvanic corrosion between W and TiN was calculated as the absolute value of the difference in corrosion potential between W and TiN. Similarly, the electromotive force of galvanic corrosion between W and TiN was calculated as the absolute value of the difference in corrosion potential between Mo and TiN. From the obtained electromotive force of galvanic corrosion, the resistance to galvanic corrosion was evaluated according to the following evaluation criteria. The smaller the electromotive force, the less likely galvanic corrosion is to occur, and in practice, a rating of "2" or higher is preferable.

[0098] 5: Less than 0.1V 4: 0.1V or more and less than 0.2V 3: 0.2V or more and less than 0.3V 2: 0.3V or more and less than 0.5V 1: 0.5V or more

[0099] [Results] The table below shows the composition and evaluation results of each chemical solution. The corrosion potential difference (TiN-W) column shows the evaluation results of the resistance to galvanic corrosion based on the corrosion potential difference between W and TiN described above, and the corrosion potential difference (TiN-Mo) column shows the evaluation results of the resistance to galvanic corrosion based on the corrosion potential difference between Mo and TiN described above. In the table, the "O, N, P, S" column indicates "A" when the corrosion inhibitor contains at least one of an oxygen atom, a nitrogen atom, a phosphorus atom, and a sulfur atom, and indicates "B" otherwise. In the table, the "aromatic ring," "aromatic heterocycle," "acidic functional group," and "N" columns indicate "A" when the corrosion inhibitor contains an aromatic ring, an aromatic heterocycle, an acidic functional group, or a nitrogen atom, respectively, and indicates "B" otherwise. In the table, the "Formula (1)" column indicates "A" when the corrosion inhibitor is a compound represented by the above-mentioned formula (1), and indicates "B" otherwise. In the table, the values ​​for the content of hydrofluoric acid and hydrochloric acid are the content of hydrogen fluoride and hydrogen chloride, respectively. Table 1-2 is a continuation of Table 1-1. For example, the chemical solution of Example 1 contains 0.2 mass% of benzofluoride, 2.9 mass% of hydrofluoric acid, 0.4 mass% of hydrochloric acid, 3.8 mass% of water, and 92.8 mass% of 1-butoxy-2-propanol.

[0100]

[0101]

[0102] From the results shown in the table above, it was confirmed that the chemical solution of the present invention can etch dry-etched modified TiN, and is less likely to cause galvanic corrosion when applied to a workpiece having an area where TiN is bonded to Mo or W.

[0103] A comparison of Examples 9 and 12 to 22 with Examples 3 to 8 and 10 to 11 confirmed that galvanic corrosion can be more effectively suppressed when the corrosion inhibitor has an aromatic ring. A comparison of Example 13 with Examples 20 to 23 confirmed that galvanic corrosion can be more effectively suppressed when the corrosion inhibitor has an acidic functional group. A comparison of Examples 1 to 2 with Examples 13 to 23 confirmed that galvanic corrosion can be more effectively suppressed when the corrosion inhibitor is a compound represented by formula (1), and that galvanic corrosion can be further suppressed when the corrosion inhibitor is a compound represented by formula (2). A comparison of Examples 23 to 31 confirmed that galvanic corrosion can be more effectively suppressed when the organic solvent is an alcohol, sulfonic acid, amide, or sulfoxide, and that galvanic corrosion can be further suppressed when the organic solvent is an alcohol. A comparison of Example 7 with Example 32 confirmed that etching performance was better when the content of the corrosion inhibitor was 0.5 mass% or less relative to the total mass of the chemical solution. A comparison between Example 7 and Example 33 confirmed that etching performance was better when the fluoride ion source was hydrofluoric acid. A comparison between Example 7 and Examples 34 to 36 confirmed that galvanic corrosion could be further suppressed when the organic solvent content was 90 mass% or more relative to the total mass of the chemical solution. A comparison between Example 7 and Examples 34 to 36 confirmed that etching performance was better when the water content was 3.5 mass% or more relative to the total mass of the chemical solution, that galvanic corrosion could be further suppressed when the water content was 7 mass% or less, and that galvanic corrosion could be further suppressed when the water content was 5 mass% or less. A comparison between Example 7 and Examples 38 and 39 confirmed that the etching rate was better when the acid pKa was 0.0 or less, and that the etching performance was even better when the acid pKa was -2.5 or less.

[0104] 100 Laminate 10 Substrate 20 Metal layer 40 TiN layer 60 Modified TiN

Claims

1. A chemical solution comprising: a corrosion inhibitor; a fluoride ion source; an acid; an organic solvent selected from the group consisting of alcohols, ethers, sulfones, amides, and sulfoxides; and water, wherein the content of the corrosion inhibitor is 1 mass% or less relative to the total mass of the chemical solution; the content of the organic solvent is 80 mass% or more relative to the total mass of the chemical solution; and the content of the water is 1 to 12 mass% relative to the total mass of the chemical solution.

2. The chemical solution according to claim 1, wherein the corrosion inhibitor contains at least one of an oxygen atom, a nitrogen atom, a phosphorus atom, and a sulfur atom.

3. The chemical solution according to claim 2, wherein the corrosion inhibitor contains an aromatic ring.

4. The chemical solution according to claim 3, wherein the corrosion inhibitor comprises an aromatic heterocycle.

5. The chemical solution of claim 4, wherein the corrosion inhibitor comprises an acidic functional group.

6. The chemical solution according to claim 5, wherein the corrosion inhibitor contains nitrogen atoms.

7. The chemical solution according to claim 6, wherein the anticorrosive agent is a compound represented by formula (1). １ -Ar-(R ２ ) ｎ Formula (1) In formula (1), R １ represents a substituent containing an acidic functional group. Ar represents a nitrogen-containing aromatic heterocycle. R ２ represents a substituent, and n represents an integer of 0 or more.

8. The chemical solution of claim 1, wherein the source of fluoride ions comprises hydrofluoric acid.

9. The chemical solution according to claim 1, wherein the content of the organic solvent is 90% by mass or more based on the total mass of the chemical solution.

10. The chemical solution according to claim 1, wherein the organic solvent is an alcohol.

11. The chemical solution according to claim 1, wherein the content of the water is 1 to 5 mass % based on the total mass of the chemical solution.

12. The chemical solution according to any one of claims 1 to 11, which is used for treating a substrate containing titanium atoms and molybdenum or tungsten.

13. A method for manufacturing a semiconductor device, comprising a step of contacting a workpiece containing titanium nitride and molybdenum or tungsten with the chemical solution according to any one of claims 1 to 11.

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