Cleaning solution and substrate cleaning method

Abstract

To provide a cleaning liquid and a method for cleaning a substrate using the cleaning liquid that, in a substrate in which base metal-containing material and noble metal-containing material are present adjacent to each other, can reduce the corrosion potential difference between the metals.SOLUTION: A cleaning liquid is to clean a substrate in which a first metal atom-containing layer containing ruthenium and a second metal atom-containing layer containing metal atoms other than ruthenium are present adjacent to each other, wherein at least one of the first metal atom-containing layer and the second metal atom-containing layer is exposed to a surface. The cleaning liquid includes: at least one hydrazine compound (A) selected from the group consisting of a compound represented by the following formula (a1), a hydrate of the compound, and a salt of the compound; and at least one basic compound (B) selected from the group consisting of amine other than the hydrazine compound (A) and the quaternary hydroxide. R1 and R2 represent an organic group not including a carbonyl group or a hydrogen atom.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cleaning solution and a method for cleaning a substrate. [Background technology]

[0002] In wiring substrates used in semiconductor devices, a liner layer, a barrier layer, or the like may be provided adjacent to the wiring layer when the wiring layer is formed. For next-generation wiring, the use of ruthenium as a material for forming these layers is being considered in order to reduce resistance and improve embedding.

[0003] The manufacturing process of a wiring board involves planarization by chemical mechanical polishing (CMP), via formation, etc. After these processes, the substrate is cleaned to remove impurities such as shavings adhering to the substrate. For example, Patent Document 1 describes an aqueous composition containing an organic base, a copper etchant, an organic ligand, and a hydrazide compound as a cleaning composition used after CMP of a copper wiring substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6751015 Summary of the Invention [Problem to be solved by the invention]

[0005] In wiring substrates that use base metals such as copper as wiring materials and precious metals such as ruthenium as liner layers, base metal-containing materials and precious metal-containing materials are adjacent to each other. When such wiring substrates are cleaned with conventional cleaning solutions, the corrosion potential difference between the base metal and the precious metal increases, making galvanic corrosion more likely to occur. Therefore, a cleaning solution that can reduce the corrosion potential difference between the base metal and the precious metal is needed.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cleaning liquid that can reduce the corrosion potential difference between metals on a substrate on which a base metal content and a precious metal content are adjacent to each other, and a method for cleaning a substrate using the cleaning liquid. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following configuration.

[0008] A first aspect of the present invention is a cleaning solution for cleaning a substrate having a first metal atom-containing layer containing ruthenium and a second metal atom-containing layer containing a metal atom other than ruthenium in contact with each other, with at least one of the first metal atom-containing layer and the second metal atom-containing layer exposed on a surface thereof, the cleaning solution comprising: at least one hydrazine compound (A) selected from the group consisting of compounds represented by the following general formula (a1), hydrates of the compounds, and salts of the compounds; and at least one basic compound (B) selected from the group consisting of amines other than the hydrazine compound (A) and quaternary hydroxides:

[0009] [ka] [In the formula, R 1 and R 2 each independently represents an organic group not containing a carbonyl group or a hydrogen atom.

[0010] A second aspect of the present invention is a cleaning solution for cleaning a substrate having a first metal atom-containing layer containing precious metal atoms and a second metal atom-containing layer containing base metal atoms in contact with each other, with at least one of the first metal atom-containing layer and the second metal atom-containing layer exposed on a surface thereof, the cleaning solution comprising: at least one hydrazine compound (A) selected from the group consisting of compounds represented by the following general formula (a1), hydrates of the compounds, and salts of the compounds; and at least one basic compound (B) selected from the group consisting of amines other than the hydrazine compound (A) and quaternary hydroxides:

[0011] [ka] [In the formula, R 1 and R 2 each independently represents an organic group not containing a carbonyl group or a hydrogen atom.

[0012] A third aspect of the present invention is a method for cleaning a substrate, the method comprising the step of using the cleaning solution according to the first or second aspect to clean a substrate having a first metal-containing layer containing ruthenium atoms and a second metal-atom-containing layer containing metal atoms other than ruthenium in contact with each other, the substrate having at least one of the first metal-atom-containing layer and the second metal-atom-containing layer exposed on a surface.

[0013] A fourth aspect of the present invention is a method for cleaning a substrate, comprising the step of using the cleaning solution according to the first or second aspect to clean a substrate having a first metal atom-containing layer containing precious metal atoms and a second metal atom-containing layer containing base metal atoms in contact with each other, wherein at least one of the first metal atom-containing layer and the second metal atom-containing layer is exposed on a surface. [Effects of the Invention]

[0014] According to the present invention, there are provided a cleaning solution capable of reducing the corrosion potential difference between metals in a substrate in which a base metal-containing substance and a precious metal-containing substance are adjacent to each other, and a method for cleaning a substrate using the cleaning solution. [Brief explanation of the drawings]

[0015] [Figure 1A] 1 illustrates an example of a substrate to which a cleaning solution according to an embodiment is applied. [Figure 1B] 1 illustrates an example of a substrate to which a cleaning solution according to an embodiment is applied. [Figure 2A] 1 illustrates an example of a substrate to which a cleaning solution according to an embodiment is applied. [Figure 2B] 1 illustrates an example of a substrate to which a cleaning solution according to an embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0016] (First Aspect: Cleaning Solution) A cleaning solution according to a first aspect of the present invention comprises at least one hydrazine compound (A) selected from the group consisting of compounds represented by the following general formula (a1), hydrates of the compounds, and salts of the compounds, and at least one basic compound (B) selected from the group consisting of amines other than the hydrazine compounds (A) and quaternary hydroxides: The cleaning solution according to this embodiment is used to clean a substrate having a first metal atom-containing layer containing ruthenium and a second metal atom-containing layer containing metal atoms other than ruthenium in contact with each other, with at least one of the first metal atom-containing layer and the second metal atom-containing layer exposed on the surface.

[0017] [ka] [In the formula, R 1 and R 2 each independently represents an organic group not containing a carbonyl group or a hydrogen atom.

[0018] <Hydrazine compound (A)> The cleaning solution according to this embodiment contains at least one hydrazine compound (A) (hereinafter also referred to as "compound (A1)") selected from the group consisting of a compound represented by general formula (a1) (hereinafter also referred to as "compound (A1)"), a hydrate of the compound, and a salt of the compound. Component (A) has the effect of reducing the corrosion potential difference between a noble metal such as ruthenium and a metal other than ruthenium (for example, a base metal such as copper) in a cleaning process for a substrate in which the two metals are adjacent to each other, as described below.

[0019] In the formula (a1), R 1 and R 2 R each independently represents an organic group not containing a carbonyl group or a hydrogen atom. 1 and R 2Since the organic group in the formula does not contain a carbonyl group, compound (A) does not become a hydrazide.

[0020] R 1 and R 2 The organic group in the formula (I) is a hydrocarbon group which may have a substituent. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0021] R 1 and R 2 The aliphatic hydrocarbon group in may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched, or may contain a ring structure. Examples of the straight-chain aliphatic hydrocarbon group include straight-chain alkyl groups having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 or 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Examples of branched aliphatic hydrocarbon groups include branched alkyl groups having 3 to 10 carbon atoms, preferably 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms, and even more preferably 3 or 4 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group. The aliphatic hydrocarbon group containing a ring structure is an aliphatic hydrocarbon group containing an alicyclic group. The alicyclic group may be a monocyclic group or a polycyclic group. Examples of the monocyclic aliphatic hydrocarbon group include groups in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms. Specific examples of the monocycloalkane include cyclopropane, cyclopentane, and cyclohexane. The aliphatic hydrocarbon group of the polycyclic group includes a group in which one hydrogen atom has been removed from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0022] R 1 and R 2 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle; a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably 1 carbon atom.

[0023] R 1 and R 2The hydrocarbon group in may have a substituent. The substituent is not particularly limited, but examples thereof include a hydroxy group, an alkyl group, and a vinyl group. However, the substituent does not include a carbonyl group.

[0024] R 1 and R 2 is preferably an aliphatic hydrocarbon group which may have a substituent or a hydrogen atom, more preferably a linear or branched alkyl group which may have a substituent or a hydrogen atom, and even more preferably a linear or branched hydroxyalkyl group, a linear or branched hydroxyalkyl group, or a hydrogen atom. The linear hydroxyalkyl group or linear alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. The branched hydroxyalkyl group or linear alkyl group preferably has 3 to 6 carbon atoms, more preferably 3 carbon atoms.

[0025] Specific examples of compound (A1) include, but are not limited to, hydrazine, 2-hydrazinoethanol, t-butylhydrazine, 1,1-diethylhydrazine, 1,2-diethylhydrazine, methylhydrazine, ethylhydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, 1,2-diisopropylhydrazine, cyclohexylhydrazine, allylhydrazine, isopropylhydrazine, and tolylhydrazine.

[0026] The component (A) may be a hydrate of compound (A1). The number of waters of hydration in the hydrate of compound (A1) is not particularly limited. Examples of the hydrate of compound (A1) include the monohydrate, dihydrate, and trihydrate. A specific example of the hydrate of compound (A1) is hydrazine monohydrate.

[0027] Component (A) may be a salt of compound (A1). The salt of compound (A1) may be a salt with an inorganic substance or a salt with an organic substance. Examples of the salt include, but are not limited to, hydrochloride, sulfate, carbonate, etc. Specific examples of the salt of compound (A1) include t-butylhydrazine hydrochloride, hydrazine sulfate, hydrazine carbonate, and tolylhydrazine hydrochloride.

[0028] The component (A) may be used alone or in combination of two or more types. The content of component (A) in the cleaning solution of this embodiment is not particularly limited, but may be 1.0% by mass (10,000 ppm) or less, preferably 0.3% by mass (3,000 ppm) or less, more preferably 0.1% by mass (1,000 ppm) or less, even more preferably 0.05% by mass (500 ppm) or less, and particularly preferably 0.02% by mass (200 ppm) or less, based on the total mass of the cleaning solution. Because component (A) also contains deleterious substances, it is preferable to use it at a low concentration as long as the effects of component (A) are exhibited. The content of component (A) in the cleaning solution of this embodiment may be, for example, 0.01% by mass (100 ppm) or less, or 0.009% by mass (90 ppm) or less. The lower limit of the content of component (A) is not particularly limited, but may be 0.0001% by mass (1 ppm) or more, preferably 0.0005% by mass (5 ppm) or more, more preferably 0.001% by mass (10 ppm) or more, even more preferably 0.002% by mass (20 ppm) or more, and particularly preferably 0.003% by mass (30 ppm) or more, relative to the total mass of the cleaning solution. When the content of component (A) is equal to or greater than the preferred lower limit, the corrosion potential difference between noble metals such as ruthenium and other metals (base metals or non-ruthenium metals described below) is likely to be reduced when a substrate is cleaned with the cleaning solution of this embodiment. The content of the component (A) in the cleaning solution of this embodiment may range from 0.0001 mass% (1 ppm) to 1.0 mass% (10,000 ppm) relative to the total mass of the cleaning solution, preferably from 0.0001 mass% (1 ppm) to 0.3 mass% (3,000 ppm) or from 0.0005 mass% (5 ppm) to 0.1 mass% (1,000 ppm), more preferably from 0.002 mass% (20 ppm) to 0.05 mass% (500 ppm), and particularly preferably from 0.002 mass% (30 ppm) to 0.02 mass% (200 ppm), or from 0.002 mass% (30 ppm) to 0.009 mass% (90 ppm).

[0029] <Basic Compound (B)> The cleaning solution of this embodiment contains at least one basic compound (B) (hereinafter also referred to as "component (B)") selected from the group consisting of an amine other than the hydrazine compound (A) and a quaternary hydroxide. Component (B) can increase the pH of the cleaning solution, improving cleaning performance.

[0030] <Quaternary hydroxide: component (B1)> The component (B) may be a quaternary hydroxide (hereinafter also referred to as "component (B1)"). Examples of the component (B1) include compounds represented by the following general formula (b1).

[0031] [ka] [In the formula, Rb 1 ~Rb 4 each independently represents a hydrocarbon group which may have a substituent; and Z represents a nitrogen atom or a phosphorus atom.

[0032] In the formula (b1), Rb 1 ~Rb 4 each independently represents a hydrocarbon group which may have a substituent. Rb 1 ~Rb 4The hydrocarbon group which may have a substituent in the formula (a1) may be an aliphatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. 1 and R 2 Examples of the aromatic hydrocarbon group include the same as those listed in R in the formula (a1). 1 and R 2 The same as those mentioned above can be mentioned.

[0033] Rb 1 ~Rb 4 The hydrocarbon group in may have a substituent. The substituent is not particularly limited, but examples thereof include a hydroxy group.

[0034] Rb 1 ~Rb 4 is preferably an aliphatic hydrocarbon group which may have a substituent, more preferably a linear or branched alkyl group which may have a substituent, and even more preferably a linear or branched hydroxyalkyl group, a linear or branched hydroxyalkyl group, or a hydrogen atom. The linear hydroxyalkyl group or linear alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. The branched hydroxyalkyl group or linear alkyl group preferably has 3 to 6 carbon atoms, more preferably 3 carbon atoms.

[0035] In the formula (b1), Z represents a nitrogen atom or a phosphorus atom.

[0036] When the component (B1) is a hydroxide of a quaternary amine, specific examples include tetraethylammonium hydroxide (TEAH), tetramethylammonium hydroxide (TMAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), tetrapropylammonium hydroxide (TPAH), dimethylbis(2-hydroxyethyl)ammonium hydroxide (DMEMAH), tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH), choline, dimethyldiethylammonium hydroxide, tetraethanolammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, and benzyltributylammonium hydroxide.

[0037] When the component (B1) is a quaternary phosphonium hydroxide, specific examples include tetrabutylphosphonium hydroxide, tetrapropylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetramethylphosphonium hydroxide, tetraphenylphosphonium hydroxide, methyltriphenylphosphonium hydroxide, ethyltriphenylphosphonium hydroxide, propyltriphenylphosphonium hydroxide, butyltriphenylphosphonium hydroxide, benzyltriphenylphosphonium hydroxide, allyltriphenylphosphonium hydroxide, dodecyltriphenylphosphonium hydroxide, tetradecyltriphenylphosphonium hydroxyde, hexadecyltriphenylphosphonium hydroxide, and hexadecyltributylphosphonium hydroxide.

[0038] As the component (B1), TEAH, TMAH, DMEMAH, THEMAH, choline, and tetrabutylphosphonium hydroxide are preferred.

[0039] <Amine other than component (A): component (B2)> Component (B) may be an amine other than component (A) (hereinafter also referred to as "component (B2)"). However, components corresponding to the aforementioned component (B1) are excluded from component (B2). Examples of component (B2) include ammonia, primary monoamines, secondary monoamines, tertiary monoamines, quaternary ammonium salts other than hydroxides, secondary cyclic amines, tertiary cyclic amines, quaternary cyclic amines, primary alkanolamines, secondary alkanolamines, tertiary alkanolamines, diamines, and polyamines. The amine of component (B2) is not particularly limited as long as it exhibits basicity, but water-soluble amines are preferred. Component (B2) is preferably one that exhibits basicity in aqueous solution. Component (B2) is preferably an aliphatic amine from the viewpoint of water solubility, etc.

[0040] Examples of primary monoamines include, but are not limited to, alkylamines such as methylamine, ethylamine, propylamine, n-butylamine, isopropylamine, and tert-butylamine; cycloalkylamines such as cyclopentylamine, cyclohexylamine, and cyclohexanemethylamine; and alkoxyamines such as methoxyethylamine, methoxypropylamine, methoxybutylamine, ethoxypropylamine, and propoxypropylamine.

[0041] Examples of secondary monoamines include, but are not limited to, alkylamines such as dimethylamine, diethylamine, methylethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, and butylmethylamine; cycloalkylamines such as N,N-dicyclohexylamine and N-cyclopentylcyclohexanamine; and alkoxyamines such as methoxy(methylamine) and N-(2-methoxyethyl)ethylamine.

[0042] Examples of tertiary monoamines include, but are not limited to, alkylamines such as trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n-butylamine, and diethylisopropylamine; and cycloalkylamines such as tricyclopentylamine and tricyclohexylamine.

[0043] Examples of the quaternary ammonium salt include quaternary ammonium fluorides, chlorides, bromides, iodides, sulfates, hydrogen sulfates, acetates, etc. Examples of the quaternary ammonium cation include those similar to the cation moiety of the formula (b1). Specific examples of quaternary ammonium salts include, but are not limited to, tetraethylammonium chloride, tetramethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, tetrapropylammonium chloride, tetraethylammonium bromide, tetramethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrapropylammonium bromide, tetraethylammonium fluoride, tetramethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride, tetrapropylammonium fluoride, tetraethylammonium iodide, tetramethylammonium iodide, tetrapropylammonium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, tetraethylammonium hydrogensulfate, tetramethylammonium hydrogensulfate, tetrapropylammonium hydrogensulfate, tetrabutylammonium hydrogensulfate, and tetrapropylammonium hydrogensulfate.

[0044] Examples of secondary cyclic amines include piperidines (compounds having a piperidine skeleton), pyrrolidines (compounds having a pyrrolidine skeleton), and morpholines (compounds having a morpholine skeleton). Examples of piperidines, which are secondary cyclic amines, include piperidine, 2-pipecoline, 3-pipecoline, 4-pipecoline, 2,6-dimethylpiperidine, and 3,5-dimethylpiperidine. Examples of pyrrolidines include pyrrolidine, 2-methylpyrrolidine, and 3-methylpyrrolidine. Examples of morpholines include morpholine, 2-methylmorpholine, and 3-methylmorpholine.

[0045] Tertiary cyclic amines include piperidines, pyrrolidines, morpholines, etc. Examples of piperidines include N-methylpiperidine, etc. Examples of pyrrolidines include N-methylpyrrolidine, etc. Examples of morpholines include N-methylmorpholine, etc.

[0046] Examples of the quaternary cyclic amine include fluorides, chlorides, bromides, iodides, sulfates, hydrogen sulfates, acetates, etc. of piperidines, pyrrolidines, morpholines, etc.

[0047] Primary alkanolamines include, but are not limited to, methanolamine, 2-aminoethanol, 1-amino-2-propanol, 2-amino-1-propanol, 4-amino-1-butanolamine, 2-amino-2-methyl-1-propanol, 2-(2-aminoethoxy)ethanol, and the like.

[0048] Secondary alkanols include, but are not limited to, N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, diethanolamine, diisopropanolamine, 2-[(hydroxymethyl)amino]ethanol, 4-methylaminobutanol, 3-piperidinemethanol, 4-piperidinemethanol, 2-piperidineethanol, 4-piperidineethanol, and the like.

[0049] Tertiary alkanols include, but are not limited to, N,N-dimethylethanolamine, N,N-dimethylpropanolamine, N,N-diethylethanolamine, N-ethyldiethanolamine, N-methyldiethanolamine, triethanolamine, triisopropanolamine, and the like.

[0050] The diamine may be any of primary, secondary, and tertiary diamines. Examples of primary diamines include, but are not limited to, ethylenediamine, butane-1,4-diamine, 1,3-propanediamine, 1,6-hexanediamine, and pentane-1,5-diamine. Examples of secondary diamines include, but are not limited to, 2-methylpiperazine, 2,3-dimethylpiperazine, 2,5-dimethylpiperazine, N,N'-dimethylethanediamine, N,N'-dimethylpropanediamine, N,N'-diethylethylenediamine, N,N'-diethylpropanediamine, and N,N'-diisopropylethylenediamine. Tertiary diamines include, but are not limited to, 4-dimethylaminopyridine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, N,N,N',N'-tetramethyl-1,3-diaminopropane, N,N,N',N'-tetramethyl-1,3-diaminobutane, N',N'-tetramethyl-1,4-diaminobutane, N,N,N',N'-tetramethylphenylenediamine, 1,2-dipiperidinoethane, and the like.

[0051] Polyamines are compounds containing three or more amino groups. Polyamines may contain any of primary, secondary, and tertiary amino groups. Examples of polyamines include spermine, spermidine, 3,3'-iminobis(propylamine), N,N-bis(3-aminopropyl)methylamine, N,N-bis(3-aminopropyl)butylamine, N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine, N,N,N'-,N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyldipropylenetriamine, tris[2-(dimethylamino)ethyl]amine, 2-aminomethylpyrimidine, 1,4-bis(3-aminopropyl)piperazine, 1-amino-4-cyclopentylpiperazine, and 1-(2-pyridyl)piperazine.

[0052] Component (B2) may be any of a tertiary amine, secondary amine, and primary amine, but is preferably a tertiary amine or secondary amine, and more preferably a tertiary amine. Component (B2) is preferably a monoamine, more preferably a tertiary monoamine or tertiary alkanolamine, and even more preferably a tertiary aliphatic monoamine or tertiary alkanolamine, with tertiary aliphatic monoamines being particularly preferred in terms of adjusting the amount of oxide film removed and tertiary alkanolamines being particularly preferred in terms of good cleanability after removal.

[0053] The component (B) is preferably the component (B1) or a tertiary amine, more preferably the component (B1), a tertiary monoamine, or a tertiary alkanolamine, still more preferably the component (B1), a tertiary aliphatic monoamine, or a tertiary alkanolamine, and particularly preferably the component (B1).

[0054] The component (B) may be used alone or in combination of two or more. The content of component (B) in the cleaning solution of this embodiment is not particularly limited, but is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, and particularly preferably 4%, 3%, or 2% by mass or less, relative to the total mass of the cleaning solution. The lower limit of the content of component (B) is not particularly limited, but may be 0.001% by mass or more, preferably 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, and particularly preferably 0.03% by mass or more, or 0.05% by mass or more, relative to the total mass of the cleaning solution. When the content of component (B) is at least the preferred lower limit, the pH of the cleaning solution can be easily maintained high. When the content of component (B) is at most the preferred upper limit, it is easier to achieve a good balance with other components. The range of the content of component (B) in the cleaning solution of this embodiment is, relative to the total mass of the cleaning solution, 0.001 mass% to 10 mass%, preferably 0.002 mass% to 5 mass%, more preferably 0.01 mass% to 3 mass%, and particularly preferably 0.02 mass% to 2.0 mass%, or 0.03 mass% to 1.5 mass%.

[0055] The cleaning solution of this embodiment may not contain the component (B1) as long as it contains the component (B2). The cleaning solution of this embodiment may not contain other components (B1) as long as it contains one type of component (B1). The cleaning solution of this embodiment may not contain, for example, one or more of the compounds exemplified above as specific examples of quaternary hydroxides.

[0056] The cleaning solution of this embodiment may contain only one component (B1) and may not contain any other component (B2). The cleaning solution of this embodiment may contain only one component (B2), and may not contain any other component (B2). The cleaning solution of this embodiment may not contain, for example, one or more compounds selected from the group consisting of primary monoamines, secondary monoamines, tertiary monoamines, quaternary ammonium salts, secondary cyclic amines, tertiary cyclic amines, quaternary cyclic amines, primary alkanolamines, secondary alkanolamines, tertiary alkanolamines, diamines, and polyamines. The cleaning solution of this embodiment may not contain, for example, one or more compounds exemplified as specific examples of these amines. The cleaning liquid of the present embodiment may not contain, for example, one or more selected from the group consisting of primary aromatic monoamines, secondary aromatic monoamines, tertiary aromatic monoamines, quaternary aromatic ammonium salts, primary aminophenols, secondary aminophenols, tertiary aminophenols, aromatic diamines, and aromatic polyamines.

[0057] <Optional ingredients> The cleaning solution of this embodiment may contain optional components in addition to the components (A) and (B), such as hydroxycarboxylic acids, water, water-soluble organic solvents, surfactants, and anticorrosive agents.

[0058] <Hydroxycarboxylic acid (C)> The cleaning liquid of this embodiment may contain a hydroxycarboxylic acid (C) (hereinafter also referred to as "component (C)"). Component (C) improves the cleaning properties of the cleaning liquid.

[0059] A hydroxycarboxylic acid is a compound containing a hydroxy group and a carboxy group. In this specification, hydroxycarboxylic acid refers to a compound consisting of a hydroxy group, a carboxy group, and a hydrocarbon group. A hydroxycarboxylic acid does not have any functional groups other than a hydroxy group and a carboxy group, and does not contain any atoms other than a hydrogen atom, an oxygen atom, and a carbon atom. The hydroxycarboxylic acid may be an aliphatic hydroxycarboxylic acid or an aromatic hydroxycarboxylic acid, but an aliphatic hydroxycarboxylic acid is preferred. Examples of the aliphatic hydroxycarboxylic acid include gluconic acid, citric acid, lactic acid, glycolic acid, malic acid, tartaric acid, glucuronic acid, glucaric acid, lactobionic acid, N-acetylneuraminic acid, N-glycolylneuraminic acid, and deaminoneuraminic acid.

[0060] The hydroxycarboxylic acid is preferably an aliphatic hydroxycarboxylic acid, more preferably gluconic acid, tartaric acid, malic acid, and citric acid, and even more preferably citric acid and gluconic acid.

[0061] The component (C) may be used alone or in combination of two or more types. When the cleaning solution of this embodiment contains component (C), the content of component (C) is not particularly limited, but is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3%, 2%, 1%, 0.8%, 0.6%, or 0.5% by mass or less, based on the total mass of the cleaning solution. The lower limit of the content of component (C) is not particularly limited, but may be 0.001% by mass or more, preferably 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, and particularly preferably 0.03% by mass or more, or 0.1% by mass or more. When the content of component (C) is equal to or greater than the preferred lower limit, cleaning performance is further improved. When the content of component (C) is equal to or less than the preferred upper limit, it is easier to achieve a balance with other components. The range of the content of component (C) in the cleaning liquid of this embodiment is, relative to the total mass of the cleaning liquid, 0.001 mass% to 10 mass%, preferably 0.005 mass% to 5 mass%, more preferably 0.01 mass% to 1 mass%, and particularly preferably 0.02 mass% to 0.8 mass%, or 0.03 mass% to 0.5 mass%. The cleaning liquid of this embodiment may not contain a hydroxycarboxylic acid, or may not contain one or more of the compounds exemplified above as specific examples of hydroxycarboxylic acids.

[0062] ≪Water≫ The cleaning solution of this embodiment preferably contains water as a solvent. The water may contain trace components that are inevitably mixed in. The water used in the cleaning solution of this embodiment is preferably purified water such as distilled water, ion-exchanged water, or ultrapure water, and more preferably ultrapure water commonly used in semiconductor manufacturing.

[0063] The water content in the cleaning solution of this embodiment is not particularly limited, but is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 97% by mass or more. The upper limit of the water content in the cleaning solution of this embodiment is not particularly limited, but is preferably less than 99.95% by mass, more preferably 99.9% by mass or less, more preferably 99.7% by mass or less, and more preferably 99.4% by mass or less.

[0064] <Corrosion inhibitor: (D)> The cleaning liquid of this embodiment may contain an anticorrosive agent. Examples of the anticorrosive agent include compounds containing a nitrogen-containing heterocycle such as a triazole ring, an imidazole ring, a pyridine ring, a phenanthroline ring, a tetrazole ring, a pyrazole ring, a pyrimidine ring, and a purine ring.

[0065] Examples of compounds containing a triazole ring include triazoles such as 1,2,3-triazole, 1,2,4-triazole, 3-amino-1H-1,2,4-triazole, 1-acetyl-1H-1,2,3-triazolo[4,5-b]pyridine, 1H-1,2,3-triazolo[4,5-b]pyridine, 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one, and 3H-1,2,3-triazolo[4,5-b]pyridin-3-ol; 1,2,3-benzotriazole, 5-methyl-1H-benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, and 2,3-dicarboxypropylbenzotriazole. and benzotriazoles such as 1,2,3-benzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-carboxyl-1H-benzotriazole methyl ester, 4-carboxyl-1H-benzotriazole butyl ester, 4-carboxyl-1H-benzotriazole octyl ester, 5-hexylbenzotriazole, [1,2,3-benzotriazolyl-1-methyl][1,2,4-triazolyl-1-methyl][2-ethylhexyl]amine, tolyltriazole, naphthotriazole, bis[(1-benzotriazolyl)methyl]phosphonic acid, and 3-aminotriazole.

[0066] Examples of compounds containing an imidazole ring include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-propylimidazole, 2-butylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-aminoimidazole, and benzimidazole; and biimidazoles such as 2,2'-biimidazole. Among these, biimidazoles are preferred, and 2,2'-biimidazole is more preferred.

[0067] Examples of compounds containing a pyridine ring include pyridines such as 1H-1,2,3-triazolo[4,5-b]pyridine, 1-acetyl-1H-1,2,3-triazolo[4,5-b]pyridine, 3-aminopyridine, 4-aminopyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetamidopyridine, 4-pyrrolidinopyridine, 2-cyanopyridine, 2,6-pyridinecarboxylic acid, and 2,4,6-trimethylpyridine; 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, and 4,4'-di-tert- Examples of the alkyl group include bipyridyls such as butyl-2,2'-bipyridyl, 4,4-dinonyl-2,2-bipyridyl, 2,2"-bipyridine-6,6'-dicarboxylic acid, and 4,4'-dimethoxy-2,2'-bipyridyl. Among these, bipyridyls are preferred, and 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, 4,4-dinonyl-2,2-bipyridyl, 2,2"-bipyridine-6,6'-dicarboxylic acid, and 4,4'-dimethoxy-2,2'-bipyridyl are more preferred.

[0068] An example of a compound containing a phenanthroline ring is 1,10-phenanthroline.

[0069] Examples of compounds containing a tetrazole ring include 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, and 1-(2-diaminoethyl)-5-mercaptotetrazole.

[0070] Examples of compounds containing a pyrazole ring include 3,5-dimethylpyrazole, 3-amino-5-methylpyrazole, 4-methylpyrazole, and 3-amino-5-hydroxypyrazole.

[0071] Examples of compounds containing a pyrimidine ring include pyrimidine, 4-methylpyrimidine, 1,2,4-triazolo[1,5-a]pyrimidine, 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine, 1,3-diphenyl-pyrimidine-2,4,6-trione, 1,4,5,6-tetrahydropyrimidine, 2,4,5,6-tetraaminopyrimidine sulfate, 2,4,5-trihydroxypyrimidine, 2,4,6-triaminopyrimidine, 2,4,6-trichloropyrimidine, 2,4,6-trimethoxypyrimidine, 2, Examples include 4,6-triphenylpyrimidine, 2,4-diamino-6-hydroxypyrimidine, 2,4-diaminopyrimidine, 2-acetamidopyrimidine, 2-aminopyrimidine, 2-methyl-5,7-diphenyl-(1,2,4)triazolo(1,5-a)pyrimidine, 2-methylsulfanyl-5,7-diphenyl-(1,2,4)triazolo(1,5-a)pyrimidine, 2-methylsulfanyl-5,7-diphenyl-4,7-dihydro-(1,2,4)triazolo(1,5-a)pyrimidine, and 4-aminopyrazolo[3,4-d]pyrimidine.

[0072] Compounds containing a purine ring include adenine, guanine, hypoxanthine, xanthine, uric acid, theophylline, and the like.

[0073] The anticorrosive agent may be used alone or in combination of two or more kinds. When the cleaning liquid of the present embodiment contains an anticorrosive agent, the content of the anticorrosive agent is not particularly limited, but is preferably 0.0001 to 0.2 mass% (1 to 2000 ppm) relative to the total mass of the cleaning liquid, more preferably 0.0003 to 0.1 mass% (3 to 1000 ppm), still more preferably 0.0005 to 0.05 mass% (5 to 500 ppm), and particularly preferably 0.001 to 0.03 mass% (10 to 300 ppm).

[0074] The cleaning solution of this embodiment may not contain one or more compounds selected from the group consisting of compounds containing a triazole ring, compounds containing an imidazole ring, compounds containing a pyridine ring, compounds containing a phenanthroline ring, compounds containing a tetrazole ring, compounds containing a pyrazole ring, compounds containing a pyrimidine ring, and compounds containing a purine ring, and may not contain one or more compounds exemplified as specific examples of the corrosion inhibitor. The cleaning solution of this embodiment may not contain a corrosion inhibitor.

[0075] ≪Buffer: (E)≫ The cleaning solution of this embodiment may contain a buffering agent, which is a compound that has the effect of suppressing changes in the pH of the solution. The buffering agent is not particularly limited as long as it is a compound having pH buffering ability. For example, a compound having a pKa of 6 to 11 can be used as the buffering agent. Examples of buffers include Good's buffers, such as 2-cyclohexylaminoethanesulfonic acid (CHES), 3-cyclohexylaminopropanesulfonic acid (CAPS), N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid (TAPS), 4-(cyclohexylamino)-1-butanesulfonic acid (CABS), tricine, bicine, 2-morpholinoethanesulfonic acid monohydrate (MES), bis(2-hydroxyethyl)aminotris(hydroxymethyl)methane (Bis-Tris), N-(2-acetamido)iminodiacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), 2-hydroxy-3-morpholinopropanesulfonic acid (M OPSO), N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), 3-morpholinopropanesulfonic acid (MOPS), N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES), 3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic acid (TAPSO), piperazine-1,4-bis(2-hydroxypropanesulfonic acid) (POPSO), 4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane-3-sulfonic acid) (HEPSO), 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS), and the like.

[0076] The buffering agent may be used alone or in combination of two or more kinds. When the cleaning solution of the present embodiment contains a buffer, the content of the buffer is not particularly limited, but may be 0.001% by mass to 10% by mass relative to the total mass of the cleaning solution, preferably 0.005% by mass to 5% by mass, more preferably 0.01% by mass to 1% by mass, and particularly preferably 0.05% by mass to 0.5% by mass, or 0.05% by mass to 0.3% by mass.

[0077] The cleaning solution of this embodiment may not contain a buffering agent, or may not contain one or more of the compounds exemplified above as specific examples of the buffering agent.

[0078] <Organic solvents> The cleaning solution of this embodiment may contain an organic solvent as long as the effect of the present invention is not impaired. The organic solvent is preferably a water-soluble organic solvent. Examples of water-soluble organic solvents include alcohols (e.g., isopropanol, ethanol, ethylene glycol, propylene glycol, glycerin, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, dipropylene glycol, furfuryl alcohol, and 2-methyl-2,4-pentanediol), dimethyl sulfoxide, and ethers (e.g., ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and propylene glycol dimethyl ether).

[0079] The water-soluble organic solvent may be used alone or in combination of two or more kinds. When the cleaning liquid of the present embodiment contains a water-soluble organic solvent, the content of the water-soluble organic solvent is preferably 50 mass % or less, more preferably 30 mass % or less, and even more preferably 20 mass % or less, based on the total amount of water and the amount of the water-soluble organic solvent. The cleaning liquid of this embodiment may not contain an organic solvent or a water-soluble organic solvent, and may not contain one or more of the compounds exemplified above as specific examples of water-soluble organic solvents.

[0080] <Surfactants> The cleaning liquid of this embodiment may contain a surfactant for the purpose of adjusting the wettability of the cleaning liquid with respect to the substrate, etc. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0081] Examples of nonionic surfactants include polyalkylene oxide alkyl phenyl ether surfactants, polyalkylene oxide alkyl ether surfactants, block polymer surfactants consisting of polyethylene oxide and polypropylene oxide, polyoxyalkylene distyrene-substituted phenyl ether surfactants, polyalkylene tribenzyl phenyl ether surfactants, and acetylene polyalkylene oxide surfactants.

[0082] Examples of anionic surfactants include alkyl sulfonic acids, alkyl benzene sulfonic acids, alkyl naphthalene sulfonic acids, alkyl diphenyl ether sulfonic acids, fatty acid amide sulfonic acids, polyoxyethylene alkyl ether carboxylic acids, polyoxyethylene alkyl ether acetic acids, polyoxyethylene alkyl ether propionic acids, alkyl phosphonic acids, and salts of fatty acids. Examples of "salts" include ammonium salts, sodium salts, potassium salts, and tetramethylammonium salts.

[0083] Examples of cationic surfactants include alkylpyridium surfactants, etc. Quaternary ammonium salt surfactants may be used as the component (B2) above.

[0084] Examples of amphoteric surfactants include betaine surfactants, amino acid surfactants, imidazoline surfactants, and amine oxide surfactants.

[0085] These surfactants are generally commercially available. One type of surfactant may be used alone, or two or more types may be used in combination. When the cleaning liquid of the present embodiment contains a surfactant, the content of the surfactant is not particularly limited, but is, for example, preferably 0.0001 to 5 mass %, more preferably 0.001 to 3 mass %, even more preferably 0.002 to 1 mass %, and particularly preferably 0.002 to 0.2 mass %, relative to the total mass of the cleaning liquid. When the content of the surfactant is within the above preferred range, the bubbles generated by the foaming agent tend to be dense.

[0086] The cleaning solution of the present embodiment may not contain one or more surfactants selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, and may not contain one or more of the compounds exemplified as these surfactants. The cleaning solution of the present embodiment may not contain a surfactant.

[0087] ≪Impurities, etc.≫ The cleaning solution of this embodiment may contain metal impurities including metal atoms such as Fe atoms, Cr atoms, Ni atoms, Zn atoms, Ca atoms, or Pb atoms. The total content of the metal atoms in the cleaning solution of this embodiment is preferably 100 mass ppt or less with respect to the total mass of the cleaning solution. The lower the lower limit of the total metal atom content, the more preferable it is, and for example, 0.001 mass ppt or more. The total metal atom content may be, for example, 0.001 mass ppt to 100 mass ppt. By setting the total metal atom content to the preferred upper limit or less, the defect suppression and residue suppression properties of the cleaning solution are improved. By setting the total metal atom content to the preferred lower limit or more, it is thought that metal atoms are less likely to be isolated and present in the system, and therefore less likely to adversely affect the overall production yield of the object to be cleaned. The content of metal impurities can be adjusted by, for example, a purification treatment such as filtering, etc. The purification treatment such as filtering may be performed on a part or all of the raw material before preparing the cleaning liquid, or may be performed after preparing the cleaning liquid.

[0088] The cleaning solution of this embodiment may contain, for example, impurities derived from organic substances (organic impurities). The total content of the organic impurities in the cleaning solution of this embodiment is preferably 5000 mass ppm or less. The lower limit of the organic impurity content is preferably as low as possible, and may be, for example, 0.1 mass ppm or more. The total content of the organic impurities may be, for example, 0.1 mass ppm to 5000 mass ppm.

[0089] The cleaning solution of this embodiment may contain countable particles of a size that can be counted by, for example, a light-scattering liquid-borne particle counter. The size of the countable particles is, for example, 0.04 μm or more. The number of countable particles in the cleaning solution of this embodiment is, for example, 1,000 or less per mL of cleaning solution, with the lower limit being, for example, 1 or more. It is believed that by keeping the number of countable particles in the cleaning solution within the above range, the metal corrosion inhibitory effect of the cleaning solution is improved.

[0090] The organic impurities and / or the entities to be counted may be added to the cleaning solution, or may be inevitably mixed into the cleaning solution during the manufacturing process of the cleaning solution. Examples of cases where organic impurities are inevitably mixed into the cleaning solution during the manufacturing process of the cleaning solution include, but are not limited to, cases where organic impurities are contained in raw materials (e.g., organic solvents) used to manufacture the cleaning solution, and cases where organic impurities are mixed in from the external environment during the manufacturing process of the cleaning solution (e.g., contamination). When the countable substances are added to the cleaning solution, the abundance ratio may be adjusted for each specific size, taking into consideration the surface roughness of the object to be cleaned, etc.

[0091] <ph> The pH of the cleaning solution of this embodiment is preferably 8 or more and 13 or less. The pH of the cleaning solution is preferably 9 or more, more preferably 10 or more, and even more preferably 11 or more. The pH of the cleaning solution is preferably 14 or less, and even more preferably 13.5 or less. The pH range of the cleaning solution is preferably pH 8 to pH 13.5, and more preferably pH 9 to 13.0. The pH value is measured using a pH meter under conditions of room temperature (23° C.) and atmospheric pressure (1 atmosphere).

[0092] <Storage container> The method for storing the cleaning solution of this embodiment is not particularly limited, and a conventionally known storage container can be used. The void ratio and / or the type of gas to fill the voids in the container during storage may be appropriately determined so as to ensure the stability of the cleaning solution. For example, the void ratio in the storage container may be about 0.01 to 30% by volume.

[0093] When using the cleaning solution of this embodiment, the cleaning solution may be diluted 2 to 2000 times to obtain a diluted solution, and then the cleaning step may be carried out using the diluted solution.

[0094] In one embodiment, the cleaning liquid may not contain one or more selected from the group consisting of hydrazide compounds, ethylene oxide-containing compounds, propylene oxide-containing compounds, alkylene oxide-containing compounds, fluorine compounds, sugars, sugar alcohols, catechols, inorganic alkali compounds, alcohols, glycerin, glycerin derivatives, ascorbic acid, carbohydrazide, hydroquinone, hydroquinone monomethyl ether, hydroxyamine, diethylhydroxyamine, dimethylglyoxime, methyl ethyl ketoxime, ammonium sulfite, carboxylic acids, polyphosphonic acids, arylphosphonic acids, ammonium salts or alkali metal salts of the above compounds, saturated aliphatic monohydric alcohols, alkoxy alcohols, glycols, glycol ethers, ketones, nitriles, aminopolycarboxylic acids, hydroxycarboxylic acids, purines, azoles, pyrimidines, thiazoles, thiazolinones, polyphenols, barbituric acid derivatives, abrasives, and Schiff bases.

[0095] <Substrate> The cleaning solution of this embodiment is applied to a substrate having a first metal atom-containing layer containing ruthenium and a second metal atom-containing layer containing metal atoms other than ruthenium (hereinafter also referred to as "non-ruthenium metal") in contact with each other, with at least one of the first metal atom-containing layer and the second metal atom-containing layer exposed on the surface.

[0096] The first metal atom-containing layer contains ruthenium atoms. The ruthenium atoms contained in the first metal atom-containing layer may be ruthenium alone, a ruthenium alloy, or a ruthenium compound. Examples of ruthenium compounds include ruthenium oxide, ruthenium nitride, and ruthenium oxynitride. The content of ruthenium in the first metal atom-containing layer is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, and may be 100% by mass, based on the total mass of the composition forming the first metal atom-containing layer. The first metal atom-containing layer can be formed by a known method, such as CVD, ALD, or PVD.

[0097] The second metal atom-containing layer contains a non-ruthenium metal. The non-ruthenium metal contained in the second metal atom-containing layer may be a non-ruthenium metal alone, a non-ruthenium metal alloy, or a non-ruthenium metal compound. Examples of non-ruthenium metal compounds include oxides of non-ruthenium metals, nitrides of non-ruthenium metals, and oxynitrides of non-ruthenium metals. Examples of metal atoms contained in the second metal atom-containing layer include base metal atoms. In this specification, base metal refers to copper, iron, nickel, aluminum, lead, zinc, tin, tungsten, molybdenum, tantalum, magnesium, cobalt, bismuth, cadmium, titanium, zirconium, antimony, manganese, beryllium, chromium, germanium, vanadium, gallium, hafnium, indium, niobium, rhenium, and thallium. Examples of the non-ruthenium metal contained in the second metal atom-containing layer include base metals as simple substances, base metal alloys, base metal oxides, base metal nitrides, and base metal oxynitrides. Specific examples of materials for forming the second metal atom-containing layer include copper, titanium nitride (TiN), and tantalum nitride (TaN). The second metal atom-containing layer can be formed by a known method, such as plating, CVD, ALD, or PVD.

[0098] In the substrate, at least one of the first metal atom-containing layer and the second metal atom-containing layer is exposed on the surface, and either one of the first metal atom-containing layer and the second metal atom-containing layer may be exposed, or both may be exposed. In the substrate, the first metal atom-containing layer and the second metal atom-containing layer are in contact with each other. The first metal atom-containing layer and the second metal atom-containing layer only need to be in at least partial contact with each other. The first metal atom-containing layer and the second metal atom-containing layer are preferably in contact with each other at a portion where at least one of the metal atom-containing layers is exposed. The first metal atom-containing layer and the second metal atom-containing layer are preferably adjacent to each other.

[0099] 1A shows an example of a substrate to which the cleaning solution of this embodiment is applied. The substrate 1 shown in FIG. 1A is, for example, a substrate after CMP of a wiring layer. In the substrate 1, a wiring layer 20 is formed on a low-k layer 30. A liner layer 10 is formed adjacent to the wiring layer 20 below the wiring layer 20. As shown in FIG. 1B, a barrier layer 11 may be formed adjacent to the liner layer 10 below the liner layer 10.

[0100] In the substrate 1, the first metal atom-containing layer may be a liner layer 10 or a wiring layer 20. When the first metal atom-containing layer is the liner layer 10, the second metal atom-containing layer becomes the wiring layer 20. When the first metal atom-containing layer is the wiring layer 20, the second metal atom-containing layer becomes the liner layer 10. When the first metal atom-containing layer is a liner layer 10, the second metal atom-containing layer preferably contains copper. For example, the first metal atom-containing layer is a ruthenium-containing liner layer 10, and the second metal atom-containing layer is a copper-containing wiring layer 20. When a barrier layer 11 is provided, the barrier layer 11 may contain TiN or TaN. The first metal-containing layer may be a barrier layer 11. In this case, the liner layer 10 may be omitted. For example, the first metal-containing layer may be a ruthenium-containing barrier layer. When the first metal atom-containing layer is the wiring layer 20, the second metal atom-containing layer preferably contains TiN or TaN. For example, the first metal atom-containing layer is the wiring layer 20 made of ruthenium, and the second metal atom-containing layer is the liner layer 10 made of TiN or TaN.

[0101] In the substrate 1, a first metal atom-containing layer containing ruthenium and a second metal-containing layer containing a non-ruthenium metal are exposed adjacent to each other on the surface. When the substrate 1 is cleaned with a cleaning solution, a corrosion potential is generated in the metal upon contact with the cleaning solution. Ruthenium contained in the first metal atom-containing layer has a high corrosion potential in conventional cleaning solutions, which increases the corrosion potential difference between the ruthenium and the non-ruthenium metal contained in the second metal atom-containing layer. This causes galvanic corrosion at the interface between the first metal atom-containing layer and the second metal atom-containing layer. Galvanic corrosion is a phenomenon in which the corrosion of one metal is accelerated when two dissimilar metals come into contact and conduct electricity in a corrosive environment, such as an electrolyte. Galvanic corrosion occurs when a corrosion cell is formed between the two metals and the environment.

[0102] On the other hand, in the cleaning solution of this embodiment, the corrosion potential of ruthenium does not become too high, and the corrosion potential difference with non-ruthenium metals is reduced, so that even when cleaning a substrate such as the substrate 1, which has a first metal atom-containing layer and a second metal atom-containing layer adjacent to each other, the occurrence of galvanic corrosion is suppressed.

[0103] 2A and 2B show another example of a substrate to which the cleaning solution of this embodiment is applied. The substrate 100 shown in FIG. 2 is a substrate after a via 140 and a trench 150 connected to a wiring layer 120 have been formed by, for example, a dual damascene process. An etch stop layer may be included (not shown) in the lower layer of the low-k layer 130 in which the via 140 is formed (the upper layer of the liner layer 110 adjacent to the wiring layer 120). In the substrate 100, the wiring layer 120 is formed in the low-k layer 130. A liner layer 110 is formed adjacent to the wiring layer 120 below the wiring layer 120. A barrier layer may be formed adjacent to the liner layer 110 below the liner layer 110. Dual damascene is a method in which a via and a trench are formed, a metal is simultaneously filled into the via and the trench by film deposition, and then excess volume is removed by polishing, thereby simultaneously filling the via and the trench.

[0104] In the substrate 100, the first metal atom-containing layer may be the liner layer 110 or the wiring layer 120. When the first metal atom-containing layer is the liner layer 110, the second metal atom-containing layer becomes the wiring layer 120. When the first metal atom-containing layer is the wiring layer 120, the second metal atom-containing layer becomes the liner layer 110. Materials for forming the liner layer 110 and the wiring layer 120 include those similar to those for the substrate 1 in FIG. 1A. When the substrate 100 has a barrier layer, the liner layer 110 may be omitted. Materials for forming the barrier layer include those similar to those for the substrate 1' in FIG. 1B.

[0105] In the substrate 100, the via 140 is formed on the wiring layer 120, and the wiring layer 120 is exposed, but the liner layer 110 is not exposed. However, misalignment of the via may occur during the via formation process, resulting in the liner layer 110 being exposed, as in the substrate 100′ shown in FIG. 2B. When the liner layer 110 and the wiring layer 120 are exposed, as in the substrate 100′, cleaning with a conventional cleaning solution causes galvanic corrosion at the interface between the liner layer 110 and the wiring layer 120 due to the corrosion potential difference between ruthenium contained in the first metal atomic layer and the non-ruthenium metal contained in the second metal atomic layer. On the other hand, the cleaning solution of the present embodiment reduces the corrosion potential difference between ruthenium and the non-ruthenium metal, thereby suppressing the occurrence of galvanic corrosion. In cleaning after via formation, misalignment of the via may result in the liner layer 110 being exposed along with the wiring layer 120. By using the cleaning solution of this embodiment, even if via misalignment occurs, the occurrence of galvanic corrosion can be suppressed.

[0106] After CMP or via formation, impurities such as metal shavings generated by these processes adhere to the substrate. Such metal shavings contain metals and metal oxides. For example, if the substrate contains a copper wiring layer, the impurities contain copper oxide (CuOx). By using the cleaning solution of this embodiment, these impurities can be efficiently removed from the substrate surface.

[0107] The cleaning solution of this embodiment contains a hydrazine compound (A) and a basic compound (B), which makes it possible to efficiently remove residues of metals and / or metal oxides derived from the first metal atom-containing layer and the second metal atom-containing layer (residues generated in processes such as dry etching and CMP) while suppressing the occurrence of galvanic corrosion, even when cleaning a substrate in which ruthenium and non-ruthenium metals are in contact with each other. In the cleaning solution of this embodiment, the hydrazine compound (A) suppresses an increase in the corrosion potential of ruthenium and reduces the corrosion potential difference with non-ruthenium metals. This is thought to suppress the occurrence of galvanic corrosion. Furthermore, the inclusion of component (B) is thought to maintain the pH of the cleaning solution appropriately, improving the cleaning properties for the above-mentioned residues (particularly metal oxide residues).

[0108] (Second Aspect: Cleaning Solution) A cleaning solution according to a second aspect of the present invention comprises at least one hydrazine compound (A) selected from the group consisting of compounds represented by general formula (a1), hydrates of the compounds, and salts of the compounds, and at least one basic compound (B) selected from the group consisting of amines other than the hydrazine compounds (A) and quaternary hydroxides. The cleaning solution according to this embodiment is used to clean a substrate having a first metal atom-containing layer containing noble metal atoms and a second metal atom-containing layer containing base metal atoms in contact with each other, with at least one of the first metal atom-containing layer and the second metal atom-containing layer exposed on the surface.

[0109] The composition of the cleaning liquid of this embodiment is the same as that of the cleaning liquid of the first aspect.

[0110] <Substrate> The cleaning solution of this embodiment is applied to a substrate having a first metal atom-containing layer containing noble metal atoms and a second metal atom-containing layer containing base metal atoms in contact with each other, with at least one of the first metal atom-containing layer and the second metal atom-containing layer exposed on the surface of the substrate.

[0111] The first metal atom-containing layer contains noble metal atoms. In this specification, the term "noble metal" refers to gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru), osmium (Os), and rhenium (Re). The noble metal atoms contained in the first metal atom-containing layer may be a simple noble metal, a noble metal alloy, or a noble metal compound. Examples of noble metal compounds include oxides of noble metals, nitrides of noble metals, and oxynitrides of noble metals. The content of the noble metal in the first metal atom-containing layer is preferably 20% by mass or more, more preferably 50% by mass or more, and even more preferably 80% by mass or more, and may be 100% by mass, based on the total mass of the composition forming the first metal atom-containing layer. The first metal atom-containing layer can be formed by a known method, such as CVD, ALD, or PVD.

[0112] The second metal atom-containing layer contains base metal atoms. The base metal atoms contained in the second metal atom-containing layer may be a base metal element, a base metal alloy, or a base metal compound. Examples of base metal compounds include base metal oxides, base metal nitrides, and base metal oxynitrides.

[0113] The substrate to which the cleaning solution of this embodiment is applied is the same as the substrate exemplified in the description of the cleaning solution of the first aspect above, except that the first metal atom-containing layer contains noble metal atoms and the second metal atom-containing layer contains base metal atoms.

[0114] When a substrate is cleaned with a conventional cleaning solution in which a first metal atom-containing layer and a second metal atom-containing layer are in contact with each other, the corrosion potential of the noble metal increases, increasing the difference in corrosion potential with the base metal, which leads to galvanic corrosion at the interface between the first metal atom-containing layer and the second metal atom-containing layer. On the other hand, the cleaning solution of the present embodiment prevents the corrosion potential of the noble metal from becoming too high, and reduces the difference in corrosion potential with the base metal, thereby preventing galvanic corrosion even when cleaning a substrate, such as the substrate 1, in which a metal atom-containing layer and a second metal atom-containing layer are adjacent to each other.

[0115] The cleaning solution of this embodiment contains a hydrazine compound (A) and a basic compound (B), which allows for efficient removal of residues such as metals and / or metal oxides from the first metal atom-containing layer and the second metal atom-containing layer (residues generated in processes such as dry etching and CMP) while suppressing the occurrence of galvanic corrosion, even when cleaning a substrate in which a noble metal and a base metal are in contact with each other. The cleaning solution of this embodiment uses the hydrazine compound (A) to suppress an increase in the corrosion potential of the noble metal and reduce the difference in corrosion potential with the base metal. This is believed to suppress the occurrence of galvanic corrosion. Furthermore, the inclusion of component (B) is believed to maintain the pH of the cleaning solution appropriately, improving the cleaning properties for the above-mentioned residues (particularly metal oxide residues).

[0116] (Substrate cleaning method: third aspect) A substrate cleaning method according to a third aspect includes a step of cleaning a substrate using the cleaning solution according to the first aspect. The substrate has a first metal-containing layer containing ruthenium atoms and a second metal-atom-containing layer containing metal atoms other than ruthenium, the first metal-atom-containing layer and the second metal-atom-containing layer being in contact with each other. At least one of the first metal-atom-containing layer and the second metal-atom-containing layer is exposed on the surface of the substrate.

[0117] <Process for cleaning the substrate: cleaning process> This step is a step of cleaning a substrate using the treatment liquid according to the first aspect. This step includes an operation of bringing the cleaning liquid into contact with the substrate. The cleaning method is not particularly limited, and any known cleaning method can be used. Examples of such methods include a method of continuously discharging a cleaning liquid onto a substrate rotating at a constant speed (single-wafer cleaning method), a method of immersing a substrate in a cleaning liquid for a certain period of time (dip method), and a method of spraying a cleaning liquid onto the surface of the substrate (spray method).

[0118] The temperature at which the cleaning treatment is carried out is not particularly limited. Examples of the temperature for the cleaning treatment include 15 to 60° C. Increasing the temperature of the treatment solution improves the cleaning performance, but the temperature of the cleaning solution can be appropriately selected in consideration of minimizing changes in the composition of the cleaning solution, and of workability, safety, cost, etc.

[0119] The cleaning time can be appropriately selected so as to be sufficient to remove impurities, residues, etc. from the substrate surface. Examples of cleaning times include 10 seconds to 30 minutes, 10 seconds to 15 minutes, 10 seconds to 10 seconds, or 10 seconds to 5 minutes.

[0120] The cleaning solution according to the first aspect may be diluted 2 to 2000 times before use to obtain a diluted solution, which may be used to clean the substrate in this step.

[0121] <Substrate> The substrate to be cleaned may be the same as that described as the target for the cleaning solution according to the first embodiment. The substrate may be a substrate after CMP of a wiring layer (e.g., FIG. 1). The substrate may also be a substrate after vias connected to the wiring layer have been formed by a dual damascene process (e.g., FIGS. 2A and 2B).

[0122] <Optional process> The method of this embodiment may include optional steps in addition to the cleaning step, such as a CMP step, a via formation step, and a contact formation step.

[0123] (CMP process) The method of this embodiment may include a CMP step before the cleaning step. The CMP step is a step of performing a CMP process on the substrate. By performing the CMP step, the surface of the substrate is planarized. The CMP step can be performed to planarize the wiring layer after a liner layer and a wiring layer are formed on the substrate. For example, a low-k layer is formed on a substrate, and trenches and vias are formed in the low-k layer. Next, a liner layer is formed, followed by a wiring layer. The substrate surface is then planarized by CMP. After CMP, shavings containing metal oxides and the like derived from the first and / or second metal atom-containing layers adhere to the substrate. However, by performing the cleaning step, the shavings can be removed while suppressing the occurrence of galvanic corrosion.

[0124] (Via formation process) The method of the present embodiment may include a via formation step before the cleaning step. The via may be formed to connect to, for example, a wiring layer. The via may be formed in a dual damascene process. For example, a low-k layer is formed on a substrate on which a liner layer and a wiring layer have been formed. An etch-stop layer containing SiCN, SiCO, Al2O3, or the like may be formed below the low-k layer. Next, vias connecting to the wiring layer are formed in the low-k layer. The vias can be formed by, for example, dry etching or wet etching. After the vias are formed, the substrate contains metal oxides derived from the first and / or second metal atom-containing layers, etching residues derived from the etch-stop layer or the low-k layer, and the like. However, by performing the cleaning step, the shavings (residues) can be removed while suppressing the occurrence of galvanic corrosion. In the via forming step, a trench may be formed along with the via. The cleaning step may be performed on the substrate after the via and trench are formed in the dual damascene process.

[0125] According to the method of the present embodiment, a substrate is cleaned using the cleaning solution according to the first aspect. Therefore, even when ruthenium and a non-ruthenium metal are present adjacent to each other, the corrosion potential difference between the two metals is reduced, the occurrence of galvanic corrosion is suppressed, and good cleaning properties can be maintained.

[0126] (Substrate cleaning method: fourth aspect) A fourth aspect of the present invention relates to a method for cleaning a substrate, which includes the step of cleaning a substrate using the cleaning solution according to the second aspect. The substrate has a first metal-containing layer containing noble metal atoms and a second metal-atom-containing layer containing base metal atoms, which are in contact with each other. At least one of the first metal-atom-containing layer and the second metal-atom-containing layer is exposed on the surface of the substrate.

[0127] <Substrate cleaning process> This step is a step of cleaning a substrate using the treatment liquid according to the second aspect, and can be carried out in the same manner as in the method for cleaning a substrate according to the third aspect.

[0128] <Optional process> The method of this embodiment may include optional steps in addition to the cleaning step. Examples of optional steps include a CMP step, a via formation step, a contact formation step, etc. These steps can be performed in the same manner as described in the substrate cleaning method according to the third aspect.

[0129] <Substrate> The substrate to be cleaned may be the same as that described as the target for the cleaning solution according to the second embodiment. The substrate may be a substrate after CMP of a wiring layer (e.g., FIG. 1). The substrate may also be a substrate after vias connected to the wiring layer have been formed by a dual damascene process (e.g., FIGS. 2A and 2B).

[0130] According to the method of the present embodiment, the substrate is cleaned using the cleaning solution according to the second aspect. Therefore, even when a noble metal and a base metal are adjacent to each other, the corrosion potential difference between the two metals is reduced, the occurrence of galvanic corrosion is suppressed, and good cleaning properties can be maintained. [Example]

[0131] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0132] <Preparation of cleaning solution> (Examples 1 to 24, Comparative Examples 1 to 5) Each component shown in Tables 1 to 3 was dissolved in water to prepare the cleaning solution for each example.

[0133] [Table 1]

[0134] [Table 2]

[0135] [Table 3]

[0136] In Tables 1 to 3, the abbreviations have the following meanings: The numbers in brackets [ ] indicate the mass % relative to the total mass of the cleaning solution. <Hydrazine compound (A)> (A)-1:2-hydrazinoethanol. (A)-2: Hydrazine monohydrate. (A)-3: t-Butylhydrazine hydrochloride.

[0137] [ka]

[0138] <Quaternary hydroxide (B1)> (B1)-1: Tetraethylammonium hydroxide (TEAH). (B1)-2: Tetramethylammonium hydroxide (TMAH). (B1)-3: Tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH). (B1)-4:Colin. (B1)-5: Tetrabutylphosphonium hydroxide.

[0139] [ka]

[0140] <Amine (B2)> (B2)-1: Triethanolamine. (B2)-2: Diethanolamine. (B2)-3: Butylamine. (B2)-4: Triethylamine.

[0141] [ka]

[0142] <Hydroxycarboxylic acid (C)> (C)-1: Citric acid. (C)-2: Gluconic acid.

[0143] [ka]

[0144] <Corrosion inhibitor (D)> (D)-1: Triazole. (D)-2: Benzotriazole (BTA). (D)-3: Adenine. (D)-4: 3-amino-1,2,4-triazole.

[0145] [ka]

[0146] <Buffer (E)> (E)-1: Bishin. (E)-2: 2-Cyclohexylaminoethanesulfonic acid (CHES). (E)-3: Tricine.

[0147] [ka]

[0148] [Evaluation of corrosion potential (ΔEcorr)] The substrates used were 12-inch silicon substrates with a ruthenium film (60 nm) formed by PVD or 8-inch silicon substrates with a copper film (30 nm) formed by PVD. Using a potentiostat (GAMRY R600+), the Tafel plots of the substrates in each cleaning solution were measured to determine the corrosion potential (Ecorr). The potentiostat's electrodes consisted of a reference electrode (Ag / AgCl), a counter electrode (Pt), and a working electrode (substrate). The corrosion potential difference (ΔEcorr) was calculated using the following formula: ΔEcorr = (Ecorr of copper substrate) - (Ecorr of ruthenium substrate)

[0149] The evaluation was carried out according to the following evaluation criteria, and the results are shown in Tables 4 to 6 as "corrosion potential difference (ΔEcorr)". Evaluation criteria: A: -100 to 100 mV B: More than 100mV C: Less than -100mV

[0150] [Evaluation of cleaning ability] The cleaning performance was evaluated as the etching rate of CuOx. The substrate used was an 8-inch silicon substrate with a copper film (30 nm) formed by PVD. The substrate was immersed in 5 mass% hydrogen peroxide solution and stirred at room temperature for 10 minutes. This treatment oxidized the copper to copper oxide (CuOx). The substrate was then removed, washed with water, and dried with a nitrogen blow. The cleaning treatment was performed using coupons prepared by cutting the substrate into 1.5 x 2 cm pieces. 100 mL of the cleaning solution for each example was placed in a 200 mL beaker, and the coupon was immersed in the solution. While the coupon was immersed, the solution was stirred at 300 rpm at room temperature. After immersion for 3 minutes, the coupon was removed, washed with water, and dried with a nitrogen blow. The copper film thickness was measured by X-ray photoelectron spectroscopy (XPS) using an X-ray photoelectron spectrometer (Rigaku Primus IV) before and after the hydrogen peroxide treatment. The reduction in copper film thickness due to the cleaning treatment was calculated and shown in Tables 4 to 6 as the CuOx etching rate (A / min).

[0151] [Table 4]

[0152] [Table 5]

[0153] [Table 6]

[0154] The results in Tables 4 to 6 confirm that the corrosion potential difference was sufficiently reduced in the cleaning solutions of Examples 1 to 24. On the other hand, the corrosion potential difference was large in the cleaning solutions of Comparative Examples 1 to 5. It was confirmed that the cleaning solutions of Examples 1 to 24 also maintained their cleaning properties. [Explanation of symbols]

[0155] 1,1',100,100' board 10,110 liner layer 11 Barrier layer 20,120 wiring layers 30,130 Low-k layers 140 Beer 150 Trench< / ph>

Claims

1. A cleaning solution for cleaning a substrate having a first metal atom-containing layer containing ruthenium and a second metal atom-containing layer containing copper in contact with each other, wherein at least one of the first metal atom-containing layer and the second metal atom-containing layer is exposed on a surface thereof, the cleaning solution comprising: at least one hydrazine compound (A) selected from the group consisting of compounds represented by the following general formula (a1), hydrates of the compounds, and salts of the compounds; at least one basic compound (B) selected from the group consisting of amines other than the hydrazine compound (A) and quaternary hydroxides; , including cleaning fluid. 【Chemical 1】 [In the formula, R １ and R ２ each independently represents an organic group not containing a carbonyl group or a hydrogen atom.

2. A cleaning solution for cleaning a substrate having a first metal atom-containing layer containing noble metal atoms and a second metal atom-containing layer containing copper in contact with each other, wherein at least one of the first metal atom-containing layer and the second metal atom-containing layer is exposed on a surface thereof, the solution comprising: at least one hydrazine compound (A) selected from the group consisting of compounds represented by the following general formula (a1), hydrates of the compounds, and salts of the compounds; at least one basic compound (B) selected from the group consisting of amines other than the hydrazine compound (A) and quaternary hydroxides; , including cleaning fluid. 【Chemistry 2】 [In the formula, R １ and R ２ each independently represents an organic group not containing a carbonyl group or a hydrogen atom.

3. The cleaning solution according to claim 1 or 2, further comprising a hydroxycarboxylic acid (C).

4. 4. The cleaning solution according to claim 1, wherein the concentration of the hydrazine compound (A) relative to the total mass of the cleaning solution is 1.0 mass % or less.

5. 5. The cleaning solution according to claim 1, wherein the basic compound (B) is at least one selected from the group consisting of quaternary hydroxides, tertiary monoamines, and tertiary alkanolamines.

6. The cleaning solution according to any one of claims 1 to 5, further comprising at least one selected from the group consisting of a buffering agent, an anticorrosive agent, a surfactant, and an organic solvent.

7. 7. The cleaning solution according to claim 6, wherein the buffer is a compound having a pKa of 6 to 11.

8. 8. The cleaning solution according to claim 1, which is used for cleaning the substrate after chemical mechanical polishing of a wiring layer, wherein the wiring layer is the first metal atom-containing layer or the second metal atom-containing layer.

9. 8. The cleaning solution according to claim 1, which is used for cleaning the substrate after vias connected to a wiring layer have been formed by a dual damascene process.

10. 10. A method for cleaning a substrate, comprising: using the cleaning solution according to claim 1 to clean a substrate having a first metal-containing layer containing ruthenium atoms and a second metal-atom-containing layer containing metal atoms other than ruthenium in contact with each other, wherein at least one of the first metal-atom-containing layer and the second metal-atom-containing layer is exposed on a surface.

11. 10. A method for cleaning a substrate, comprising: using the cleaning solution according to claim 1 to clean a substrate having a first metal atom-containing layer containing noble metal atoms and a second metal atom-containing layer containing base metal atoms in contact with each other, wherein at least one of the first metal atom-containing layer and the second metal atom-containing layer is exposed on a surface.

12. 12. The method for cleaning a substrate according to claim 10, wherein the substrate is a substrate after chemical mechanical polishing of a wiring layer, and the wiring layer is the first metal atom-containing layer or the second metal atom-containing layer.

13. 13. The method for cleaning a substrate according to claim 10, wherein the first metal atom-containing layer is a ruthenium-containing barrier layer or a ruthenium-containing liner layer, and the second metal atom-containing layer is a copper-containing wiring layer.

14. The method for cleaning a substrate according to claim 13 , wherein the substrate is a substrate after chemical mechanical polishing of the copper-containing wiring layer.

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