Cleaning fluid and cleaning method for semiconductor substrate

Abstract

To provide a cleaning fluid that is a cleaning fluid for a semiconductor substrate having been subjected to CMP and also superior in selectivity of removal performance for RuO2, and a cleaning method for the semiconductor substrate having been subjected to CMP.SOLUTION: There is provided a cleaning fluid for a semiconductor substrate that has been subjected to a chemical machine polishing treatment, and includes a perhalogen acid and a halogen acid.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In the manufacture of semiconductor devices, a chemical mechanical polishing (CMP) process may be performed to planarize a substrate surface having a metal wiring film, a barrier metal, an insulating film, etc., using a polishing slurry containing polishing particles (e.g., silica, alumina, etc.). In the CMP process, metal components derived from the polishing particles used in the CMP process, the polished wiring metal film, and / or the barrier metal, etc., tend to remain on the semiconductor substrate surface after polishing. These residues can cause short circuits between wirings and affect the electrical characteristics of the semiconductor, so a cleaning process is generally carried out to remove these residues from the surface of the semiconductor substrate.

[0003] For example, Patent Document 1 discloses a processing solution for etching Ru metal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-240985 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, semiconductor substrates having Ru wiring have been studied for further semiconductor integration and speedup. In the manufacturing process of semiconductor substrates having Ru wiring, it is required to selectively remove RuO2 during cleaning after CMP. Specifically, it is desirable for the cleaning solution in the cleaning process after CMP to maintain or improve the removal rate of RuO2 formed on the Ru surface during CMP while suppressing the removal rate of Ru that will eventually become the wiring. In other words, it is required that the rate ratio of the removal rate of RuO2 to the removal rate of Ru be high. Hereinafter, the rate ratio of the removal rate of RuO2 to the removal rate of Ru is also referred to as the selectivity of the removal performance of RuO2.

[0006] On the other hand, the present inventors have studied the etching treatment solution described in Patent Document 1 for semiconductor substrates containing Ru, and have found that there is room for further improvement in the selectivity of the RuO2 removal performance in the cleaning process after CMP.

[0007] An object of the present invention is to provide a cleaning liquid for semiconductor substrates that have been subjected to CMP, which has excellent selectivity in the performance of removing RuO2. Another object of the present invention is to provide a method for cleaning a semiconductor substrate that has been subjected to CMP. [Means for solving the problem]

[0008] The present inventors have found that the above problems can be solved by the following configuration.

[0009] [1] A cleaning solution for a semiconductor substrate that has been subjected to a chemical mechanical polishing process, comprising: A cleaning solution comprising a perhalogen acid and a halogen acid. [2] The cleaning solution according to [1], wherein the pH value of the cleaning solution is 2.0 to 12.0. [3] The cleaning solution according to [1] or [2], wherein a mass ratio of the content of the perhalogen acid to the content of the halogen acid is 0.00001 to 50. [4] The cleaning solution according to any one of [1] to [3], further comprising an organic base compound. [5] The cleaning solution according to [4], wherein the organic base compound comprises at least one selected from the group consisting of a first amine compound represented by the formula (1) described below, a quaternary ammonium compound, and a quaternary phosphonium compound. [6] The cleaning solution according to any one of [1] to [5], further comprising an organic acid. [7] The cleaning solution according to [6], wherein the organic acid has at least one selected from the group consisting of a carboxyl group and a phosphonic acid group. [8] The cleaning solution according to any one of [1] to [7], further comprising at least one selected from the group consisting of an anticorrosive, a surfactant, a polymer A having a weight-average molecular weight of 500 or more and less than 2000, and a polymer B having a weight-average molecular weight of 2000 or more. [9] Further comprising a corrosion inhibitor; The cleaning solution according to any one of [1] to [8], wherein the anticorrosive agent is a heterocyclic compound.

[10] The cleaning solution according to [9], wherein the corrosion inhibitor comprises at least one selected from the group consisting of a tetrazole compound, a triazole compound, an imidazole compound, a pyrazole compound, and derivatives thereof.

[11] Further comprising a surfactant, The cleaning liquid according to any one of [1] to

[10] , wherein the surfactant is an anionic or nonionic surfactant.

[12] Further comprising a polymer B having a molecular weight of 2000 or more, The cleaning solution according to any one of [1] to

[11] , wherein the polymer B has a carboxyl group or an acid anhydride group.

[13] A method for cleaning a semiconductor substrate, comprising the step of cleaning a semiconductor substrate that has been subjected to a chemical mechanical polishing process, with the cleaning solution according to any one of [1] to

[12] . Effect of the Invention

[0010] According to the present invention, it is possible to provide a cleaning liquid for a semiconductor substrate that has been subjected to CMP, which has excellent selectivity in the performance of removing RuO2. Furthermore, the present invention can provide a method for cleaning a semiconductor substrate that has been subjected to CMP. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An example of an embodiment of the present invention will be described below. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] In this specification, when two or more types of a component are present, the "content" of the component means the total content of those two or more components. In this specification, "ppm" stands for "parts-per-million (10 -6 ) and "ppb" stands for "parts-per-billion (10 -9 )". In the compounds described in the present specification, unless otherwise limited, isomers (compounds having the same number of atoms but different structures), optical isomers, and isotopes may be included. In addition, only one type of isomer and isotope may be included, or multiple types may be included.

[0013] As used herein, psi refers to pound-force per square inch, with 1 psi = 6894.76 Pa.

[0014] The cleaning solution of the present invention (hereinafter also simply referred to as "cleaning solution") is a cleaning solution for semiconductor substrates that have been subjected to chemical mechanical polishing (CMP), and contains a perhalogen acid and a halogen acid.

[0015] The present inventors have discovered that the selectivity of the RuO2 removal performance (hereinafter also referred to as the "effect of the present invention") is improved in a cleaning solution used in a cleaning process for a semiconductor substrate containing Ru that has been subjected to CMP, by containing a perhalogen acid and a halogen acid, and have completed the present invention.

[0016] Although the detailed mechanism by which such a cleaning solution provides the effects of the present invention is unclear, it is speculated that by containing a perhalogen acid and a halogen acid, the perhalogen acid improves the RuO2 removal performance, and the halogen acid suppresses the Ru removal performance, resulting in high selectivity for RuO2.

[0017] [Cleaning solution] The cleaning solution contains a perhalogen acid and a halogen acid. Each component contained in the cleaning solution will be described below.

[0018] [Perhalogen acid] The cleaning solution of the present invention comprises a perhalogen acid. By perhalogen acid is meant a peroxide containing a halogen atom. Examples of perhalogen acids include periodic acid, perchloric acid, perbromic acid, and salts thereof. Among these, the perhalogen acid is preferably periodic acid or perchloric acid, and more preferably periodic acid, in terms of the superior effect of the present invention.

[0019] The periodic acid is not particularly limited, but in terms of the superior effect of the present invention, at least one selected from the group consisting of orthoperiodic acid (H5IO6), metaperiodic acid (HIO4), and salts thereof is preferred, and orthoperiodic acid or metaperiodic acid is more preferred. Orthoperiodic acid is even more preferred in terms of not containing an alkali metal such as sodium (Na) and having a stable composition.

[0020] Salts of perhalogen acids include, for example, alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium, calcium, and barium; and ammonium salts.

[0021] The perhalogen acids may be used alone or in combination of two or more. The content of the perhalogen acid is preferably from 0.00001 to 5 mass %, more preferably from 0.0001 to 3 mass %, and even more preferably from 0.0001 to 2.5 mass %, based on the total mass of the cleaning liquid, in that the effects of the present invention are more excellent. The content of the perhalogen acid is preferably 0.0001 to 80 mass%, more preferably 0.001 to 75 mass%, and even more preferably 0.001 to 70 mass%, based on the total mass of the components excluding the solvent in the cleaning liquid, in terms of better effects of the present invention. The total mass of the components in the cleaning solution excluding the solvent means the total mass of the components (eg, perhalogen acid, halogen acid, etc.) other than the solvent such as water in the cleaning solution.

[0022] [Halogen acids] The cleaning solution of the present invention contains a halogen acid. The halogen acid means an oxide containing a halogen atom which has one less oxygen atom than the perhalogen acid described above. In other words, the halogen acid does not include perhalogen acids and hypohalous acids.

[0023] Examples of halogen acids include iodic acid, chloric acid, bromic acid, and salts thereof. Among them, in terms of the superior effect of the present invention, iodic acid or chloric acid is preferred as the halogen acid, and iodic acid is more preferred.

[0024] Examples of salts of halogen acids include alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium, calcium, and barium; and ammonium salts.

[0025] The halogen acids may be used alone or in combination of two or more. The content of the halogen acid is preferably from 0.0005 to 4.5 mass %, more preferably from 0.05 to 4.5 mass %, and even more preferably from 3 to 4.5 mass %, based on the total mass of the cleaning liquid, in that the effects of the present invention are more excellent. In addition, the content of the halogen acid is preferably 0.01 to 99.99 mass%, more preferably 1.0 to 85 mass%, and even more preferably 40 to 85 mass%, based on the total mass of the components excluding the solvent in the cleaning liquid, in terms of better effects of the present invention.

[0026] The mass ratio of the perhalogen acid content to the halogen acid content [perhalogen acid content / halogen acid content] is preferably 0.00001 to 5000, more preferably 0.00001 to 50, still more preferably 0.00001 to 0.9, particularly preferably 0.0001 to 0.9, and most preferably 0.0003 to 0.5.

[0027] [pH value] The pH value of the cleaning solution is preferably 1 to 14 at 25°C. Among these, the pH value is preferably from 2.0 to 12.0, and more preferably from 4.0 to 12.0, in terms of obtaining better effects of the present invention. The pH value of the cleaning liquid can be adjusted by using a component having a function of a pH adjuster, such as a pH adjuster, an organic base compound, an organic acid, an anticorrosive agent, or a surfactant, which will be described later. The pH value of the cleaning solution can be measured using a known pH meter according to a method in accordance with JIS Z8802-1984. As described below, when the cleaning liquid is diluted before use, it is preferable that the pH value of the diluted liquid is within the above range.

[0028] [Optional ingredients] The cleaning solution may contain other optional components in addition to the above-mentioned components, such as an organic base compound, an organic acid, an anticorrosive agent, a surfactant, a pH adjuster, various additives, and water. The cleaning liquid preferably contains at least one selected from the group consisting of an organic base compound, an organic acid, a surfactant (more preferably an anionic surfactant), a pH adjuster, and a polymer. The optional components may be used alone or in combination of two or more.

[0029] The optional components will be described below.

[0030] <Organic base compounds> The cleaning liquid may contain an organic base compound (hereinafter also referred to as a "specific organic base compound"). The specific organic base compound means an organic compound that exhibits basicity when dissolved in a solvent. Examples of the specific organic base compound include a first amine compound, a second amine compound, and a quaternary phosphonium salt, which will be described later.

[0031] (First amine compound) The cleaning liquid of the present invention may contain a first amine compound (hereinafter also referred to as "primary amine") represented by the following formula (1):

[0032] [ka]

[0033] In formula (1), R 1 , R 2 , and R 3 Each represents an organic group. 1 , R 2 , and R 3 A plurality of these may be bonded to each other to form a non-aromatic ring which may have a substituent.

[0034] R 1 , R 2 , and R 3The organic group represented by the formula (I) includes an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, and an aryl group. These groups may have a substituent. The substituent may be a hydroxyl group or an amino group. The alkyl group, the alkenyl group, and the alkynyl group may be either a straight chain or a branched chain. R 1 , R 2 , and R 3 The carbon number of the organic group represented by the following formula is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and further preferably 1 to 3.

[0035] R 1 , R 2 , and R 3 The non-aromatic ring formed by bonding together of a plurality of the above, which may have a substituent, is not particularly limited, but examples thereof include a cycloalkane ring having 5 to 10 carbon atoms, and a cyclopentane ring, a cyclohexane ring, or a cycloheptane ring is preferable. Examples of the substituent that the non-aromatic ring may have include alkyl groups having 1 to 4 carbon atoms.

[0036] R 1 , R 2 , and R 3 The organic group represented by the formula (I) is preferably an alkyl group which may have a hydroxyl group, more preferably an alkyl group having 1 to 5 carbon atoms which may have a hydroxyl group, still more preferably an alkyl group having 1 to 3 carbon atoms which may have a hydroxyl group, and particularly preferably a methyl group or ethyl group which may have a hydroxyl group. Among them, R 1 , R 2 , and R 3 Among these, a combination in which 0 to 2 are alkyl groups having a hydroxyl group and the remaining 1 to 3 are alkyl groups not having a hydroxyl group is more preferable.

[0037] The primary amine preferably contains a primary amino alcohol in order to provide a cleaning solution with superior stability over time. 1 , R 2, and R 3 It is preferable that at least one of the organic groups represented by the following formula (I) has a hydroxyl group. As the primary amino alcohol, R 1 , R 2 , and R 3 It is preferable that one or two of the organic groups represented by R 1 , R 2 , and R 3 It is more preferred that only one of the organic groups represented by the formula:

[0038] The first acid dissociation constant (hereinafter also referred to as "pKa1") of the conjugate acid of the primary amine is preferably 8.5 or more. When the pKa1 of the primary amine is 8.5 or more, the pH of the cleaning solution becomes more stable, and the cleaning performance and corrosion prevention performance of the cleaning solution are improved. The pKa1 of the primary amine is preferably 8.8 or more, more preferably 9.0 or more, in terms of better cleaning performance and corrosion prevention performance. There is no particular upper limit, but it is preferably 12.0 or less.

[0039] Examples of primary amino alcohols include 2-amino-2-methyl-1-propanol (AMP) (pKa 1:9.72), 2-amino-2-methyl-1,3-dipropanol (AMPD) (pKa 1:8.80), and 2-amino-2-ethyl-1,3-dipropanol (AEPD) (pKa 1:8.80). The primary amine is preferably AMP, AMPD or AEPD, and more preferably AMP.

[0040] The primary amines may be used alone or in combination of two or more. The content of the primary amine in the cleaning solution is not particularly limited, but is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total mass of the cleaning solution. The upper limit is not particularly limited, but in terms of superior corrosion prevention performance, it is preferably 25% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the total mass of the cleaning solution. The content of the primary amine is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a better effect of the present invention. There is no particular upper limit, but the content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a better effect of the present invention.

[0041] (Second Amine Compound) The cleaning solution may contain a second amine compound (hereinafter also referred to as "secondary amine") different from the primary amine. Examples of secondary amines include primary aliphatic amines having a primary amino group (-NH2) in the molecule, secondary aliphatic amines having a secondary amino group (>NH) in the molecule, tertiary aliphatic amines having a tertiary amino group (>N-) in the molecule, and quaternary ammonium compounds which are compounds having a quaternary ammonium cation or salts thereof, with quaternary ammonium compounds being preferred.

[0042] -Quaternary ammonium compounds- The quaternary ammonium compound is not particularly limited as long as it is a compound having a quaternary ammonium cation in which four hydrocarbon groups (preferably alkyl groups) are substituted on a nitrogen atom, or a salt thereof. Examples of the quaternary ammonium compound include quaternary ammonium hydroxide, quaternary ammonium fluoride, quaternary ammonium bromide, quaternary ammonium iodide, quaternary ammonium acetate, and quaternary ammonium carbonate. Among them, quaternary ammonium hydroxide is preferred.

[0043] The quaternary ammonium compound is preferably a quaternary ammonium hydroxide represented by the following formula (2).

[0044] (R 4 )4N + OH - (2)

[0045] In the formula, R 4 represents an alkyl group which may have a hydroxyl group or a phenyl group as a substituent. 4 may be the same or different from each other.

[0046] R 4 The alkyl group represented by the following formula (1) is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a propyl group or a butyl group. R 4 The alkyl group which may have a hydroxyl group or a phenyl group, represented by the formula (I), is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a 2-hydroxyethyl group, or a benzyl group, more preferably a methyl group, an ethyl group, a propyl group, a butyl group, or a 2-hydroxyethyl group, and even more preferably a propyl group, a butyl group, or a 2-hydroxyethyl group.

[0047] Examples of quaternary ammonium compounds include tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), tetramethylammonium hydroxide (TMAH), trimethylethylammonium hydroxide (TMEAH), diethyldimethylammonium hydroxide (DEDMAH), methyltriethylammonium hydroxide (MTEAH), 2-hydroxyethyltrimethylammonium hydroxide (choline), bis(2-hydroxyethyl)dimethylammonium hydroxide, tri(2-hydroxyethyl)methylammonium hydroxide, tetra(2-hydroxyethyl)ammonium hydroxide, benzyltrimethylammonium hydroxide (BTMAH), and cetyltrimethylammonium hydroxide. As quaternary ammonium compounds other than the above specific examples, for example, the compounds described in paragraph

[0021] of JP 2018-107353 A can be used, the contents of which are incorporated herein by reference.

[0048] The quaternary ammonium compound used in the cleaning solution is preferably, for example, TEAH, TPAH, TBAH, TMAH, TMEAH, DEDMAH, MTEAH, choline, or bis(2-hydroxyethyl)dimethylammonium hydroxide, more preferably DEDMAH, MTEAH, TEAH, TPAH, or TBAH, and even more preferably TEAH, TPAH, or TBAH.

[0049] - Primary to tertiary aliphatic amines - The primary to tertiary aliphatic amines are not particularly limited as long as they are compounds or salts thereof having in the molecule a group selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group (hereinafter, these may be collectively referred to as "primary to tertiary amino groups"), do not have an aromatic ring, and are not included in the above-mentioned primary amines. Examples of salts of primary to tertiary aliphatic amines include salts with inorganic acids in which at least one nonmetal selected from the group consisting of Cl, S, N, and P is bonded to hydrogen, and hydrochlorides, sulfates, or nitrates are preferred.

[0050] Examples of the primary to tertiary aliphatic amines include amino alcohols, alicyclic amine compounds, and aliphatic monoamine compounds other than amino alcohols and alicyclic amines, and aliphatic polyamine compounds.

[0051] = Amino alcohol = The amino alcohol is a compound of primary to tertiary aliphatic amines further having at least one hydroxyl alkyl group in the molecule. The amino alcohol may have any of primary to tertiary amino groups, but preferably has a primary amino group.

[0052] Examples of amino alcohols contained in the primary to tertiary aliphatic amines include monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diethylene glycolamine (DEGA), trishydroxymethylaminomethane (Tris), 2-(methylamino)-2-methyl-1-propanol (N-MAMP), 2-(aminoethoxy)ethanol (AEE), and 2-(2-aminoethylamino)ethanol (AAE). Among these, N-MAMP, MEA, DEA, AEE, or AAE is preferred, and N-MAMP, MEA, or AEE is more preferred. In terms of excellent cleaning performance, MEA, DEA, AEE, or AAE is more preferred.

[0053] =Alicyclic amine compounds= The alicyclic amine compound is not particularly limited as long as it is a compound having a non-aromatic heterocycle in which at least one of the atoms constituting the ring is a nitrogen atom. Examples of the alicyclic amine compound include a cyclic amidine compound and a piperazine compound.

[0054] Cyclic amidine compounds are compounds that have a heterocycle containing an amidine structure (>NC=N-) in the ring. The number of ring members in the heterocycle of the cyclic amidine compound is not particularly limited, but is preferably 5 or 6, and more preferably 6. Examples of cyclic amidine compounds include diazabicycloundecene (1,8-diazabicyclo[5.4.0]undec-7-ene: DBU), diazabicyclononene (1,5-diazabicyclo[4.3.0]non-5-ene: DBN), 3,4,6,7,8,9,10,11-octahydro-2H-pyrimido[1.2-a]azocine, 3,4,6,7,8,9-hexahydro-2H-pyrido[1.2-a]pyrimidine, 2,5,6,7-tetrahydro-3H-pyrrolo[1.2-a]imidazole, 3-ethyl-2,3,4,6,7,8,9,10-octahydropyrimido[1.2-a]azepine, and creatinine, with DBU being preferred.

[0055] The piperazine compound is a compound having a six-membered hetero ring (piperazine ring) in which opposing --CH-- groups of a cyclohexane ring are replaced with nitrogen atoms. The piperazine compound may have a substituent on the piperazine ring, for example, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, and an aryl group having 6 to 10 carbon atoms.

[0056] Examples of the piperazine compound include piperazine, 1-methylpiperazine, 1-ethylpiperazine, 1-propylpiperazine, 1-butylpiperazine, 2-methylpiperazine, 1,4-dimethylpiperazine, 2,5-dimethylpiperazine, 2,6-dimethylpiperazine, 1-phenylpiperazine, 2-hydroxypiperazine, 2-hydroxymethylpiperazine, and 1-(2-hydroxyethyl)piperazine. (HEP), N-(2-aminoethyl)piperazine (AEP), 1,4-bis(2-hydroxyethyl)piperazine (BHEP), 1,4-bis(2-aminoethyl)piperazine (BAEP), and 1,4-bis(3-aminopropyl)piperazine (BAPP), with piperazine, 1-methylpiperazine, 2-methylpiperazine, HEP, AEP, BHEP, BAEP, or BAPP being preferred.

[0057] In addition to the above, examples of the alicyclic amine compound include compounds having a non-aromatic 5-membered hetero ring, such as 1,3-dimethyl-2-imidazolidinone and imidazolidinethione, and compounds having a 7-membered ring containing a nitrogen atom.

[0058] = Aliphatic monoamine compounds = The aliphatic monoamine compounds other than amino alcohols and alicyclic amines are not particularly limited as long as they are compounds that are not included in the primary amines, and examples thereof include methylamine, ethylamine, propylamine, dimethylamine, diethylamine, n-butylamine, 3-methoxypropylamine, tert-butylamine, n-hexylamine, cyclohexylamine, n-octylamine, 2-ethylhexylamine, and 4-(2-aminoethyl)morpholine (AEM).

[0059] = Aliphatic polyamine compound = Examples of aliphatic polyamine compounds other than amino alcohols and alicyclic amines include alkylenediamines such as ethylenediamine (EDA), 1,3-propanediamine (PDA), 1,2-propanediamine, 1,3-butanediamine, and 1,4-butanediamine, as well as polyalkylpolyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), bis(aminopropyl)ethylenediamine (BAPEDA), and tetraethylenepentamine.

[0060] In addition, as the primary to tertiary aliphatic amines, compounds not included in the category of primary amines among those described in paragraphs

[0034] to

[0056] of the specification of WO 2013 / 162020 can be used, the contents of which are incorporated herein by reference.

[0061] The primary to tertiary aliphatic amines preferably have one or more hydrophilic groups in addition to one of the primary to tertiary amino groups. Examples of the hydrophilic group include primary to tertiary amino groups and hydroxyl groups. Examples of the primary to tertiary aliphatic amines having one or more hydrophilic groups in addition to one of the primary to tertiary amino groups include compounds having two or more hydrophilic groups among amino alcohols, aliphatic polyamine compounds, and alicyclic amine compounds, and amino alcohols or cyclic amidine compounds are preferred. The upper limit of the total number of hydrophilic groups contained in the primary to tertiary aliphatic amines is not particularly limited, but is preferably 4 or less, and more preferably 3 or less.

[0062] The number of primary to tertiary amino groups that the primary to tertiary aliphatic amines have is not particularly limited, but is preferably 1 to 4, and more preferably 1 to 3. Further, the molecular weight of the primary to tertiary aliphatic amines is not particularly limited, but is preferably 200 or less, and more preferably 150 or less. There is no particular lower limit, but it is preferably 60 or more.

[0063] The first acid dissociation constant (pKa1) of the conjugate acid of the secondary amine is preferably 8.5 or more, more preferably 8.6 or more, and even more preferably 8.7 or more, in terms of superior stability over time of the cleaning solution. There is no particular upper limit, but it is preferably 20.0 or less.

[0064] As the secondary amine, primary to tertiary aliphatic amines corresponding to quaternary ammonium compounds, amino alcohols, or cyclic amidine compounds are preferred, with TEAH (pKa1:>14.0), TPAH (pKa1:>14.0), TBAH (pKa1:>14.0), N-MAMP (pKa1:9.72), MEA (pKa1:9.50), DEA (pKa1:8.70), AEE (pKa1:10.60), AAE (pKa1:10.80), DEDMAH (pKa1:>14.0), MTEAH (pKa1:>14.0), or DBU being more preferred, with TEAH, TPAH, TBAH, N-MAMP, MEA, AEE, MTEAH, or DBU being even more preferred, with TEAH, TPAH, TBAH, or DBU being particularly preferred.

[0065] The secondary amine may be used alone or in combination of two or more. The cleaning solution preferably contains two or more types of secondary amine. When the cleaning solution contains two or more types of secondary amines, it preferably contains one or more primary to tertiary aliphatic amines corresponding to amino alcohols or alicyclic amine compounds, and one or more quaternary ammonium compounds, and more preferably contains a combination of the compounds described as the respective preferred specific examples.

[0066] The content of the secondary amine in the cleaning solution is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more, based on the total mass of the cleaning solution. The upper limit of the content of the secondary amine is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on the total mass of the cleaning solution, in terms of excellent corrosion prevention properties for metal films. The content of the secondary amine is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a better effect of the present invention. There is no particular upper limit, but the content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a better effect of the present invention.

[0067] (Quaternary phosphonium salts) Quaternary phosphonium salts include, for example, tetraalkylphosphonium salts, trialkylarylphosphonium salts, dialkyldiarylphosphonium salts, alkyltriarylphosphonium salts, and tetraarylphosphonium salts.

[0068] The anion of the quaternary phosphonium salt is, for example, a halogen ion (e.g., F - , Cl - , Br - , and I - ), hydroxide ion, nitrate ion, nitrite ion, hypochlorite ion, chlorite ion, chlorate ion, perchlorate ion, acetate ion, hydrogen carbonate ion, phosphate ion, sulfate ion, hydrogen sulfate ion, sulfite ion, thiosulfate ion, and carbonate ion.

[0069] Examples of the quaternary phosphonium salt include methyltriphenylphosphonium salt, ethyltriphenylphosphonium salt, triphenylpropylphosphonium salt, isopropyltriphenylphosphonium salt, butyltriphenylphosphonium salt, pentyltriphenylphosphonium salt, hexyltriphenylphosphonium salt, n-heptyltriphenylphosphonium salt, triphenyl(tetradecyl)phosphonium salt, tetraphenylphosphonium salt, benzyltriphenylphosphonium salt, (2-hydroxybenzyl)triphenylphosphonium salt, (2-chlorobenzyl)triphenylphosphonium salt, (4-chlorobenzyl)triphenylphosphonium salt, (2,4-dichlorobenzyl)phenylphosphonium salt, (4-nitrobenzyl)triphenylphosphonium salt, 4-ethyl ...

[0043] Examples of the phosphonium salt include methoxybenzyltriphenylphosphonium salt, (1-naphthylmethyl)triphenylphosphonium salt, (cyanomethyl)triphenylphosphonium salt, (methoxymethyl)triphenylphosphonium salt, (formylmethyl)triphenylphosphonium salt, acetonyltriphenylphosphonium salt, phenacyltriphenylphosphonium salt, methoxycarbonylmethyl(triphenyl)phosphonium salt, ethoxycarbonylmethyl(triphenyl)phosphonium salt, (3-carboxypropyl)triphenylphosphonium salt, (4-carboxybutyl)triphenylphosphonium salt, 2-dimethylaminoethyltriphenylphosphonium salt, triphenylvinylphosphonium salt, allyltriphenylphosphonium salt, and triphenylpropargylphosphonium salt.

[0070] The quaternary phosphonium salt may be used alone or in combination of two or more kinds. The content of the quaternary phosphonium salt in the cleaning solution is not particularly limited, but is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more, based on the total mass of the cleaning solution. The upper limit is not particularly limited, but in terms of better corrosion prevention performance, it is preferably 25% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the total mass of the cleaning solution. The content of the quaternary phosphonium salt is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a more excellent effect of the present invention. There is no particular upper limit, but the content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a more excellent effect of the present invention.

[0071] The specific organic base compound is preferably at least one compound selected from the group consisting of primary amines, secondary amines, and quaternary phosphonium salts, and more preferably AMP, TEAH, TPAH, TBAH, or DBU.

[0072] The specific organic base compound may be used alone or in combination of two or more kinds. The content of the specific organic base compound is not particularly limited, but is preferably 0.05% by mass or more, more preferably more than 0.1% by mass, and even more preferably 1% by mass or more, based on the total mass of the cleaning solution. The upper limit is not particularly limited, but in terms of better effects of the present invention, it is preferably 25% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the total mass of the cleaning solution. The content of the specific organic base compound is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a better effect of the present invention. There is no particular upper limit, but the content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to provide a better effect of the present invention.

[0073] <Organic acid> An organic acid is an organic compound that has an acidic functional group and exhibits acidity (pH less than 7.0) in an aqueous solution. Examples of the acidic functional group include a carboxyl group, a phosphonic acid group, a sulfo group, a phenolic hydroxyl group, and a mercapto group, and carboxylic acid or phosphonic acid is preferred. In this specification, compounds that function as anionic surfactants, which will be described later, are not included in the organic acids.

[0074] The organic acid is not particularly limited, but examples thereof include a carboxylic acid having a carboxyl group in the molecule (carboxylic acid), a phosphonic acid having a phosphonic acid group in the molecule (phosphonic acid), and a sulfonic acid having a sulfo group in the molecule (sulfonic acid), and carboxylic acid or phosphonic acid is preferred.

[0075] The number of acidic functional groups that the organic acid has is not particularly limited, but is preferably 1 to 10, more preferably 2 to 9, and even more preferably 3 to 8. In addition, the organic acid is preferably a compound having a function of chelating with metals contained in the residue, from the viewpoint of superior cleaning performance, and more preferably a compound having two or more functional groups (coordination groups) in the molecule that form coordinate bonds with metal ions. Examples of the coordination group include the above-mentioned acidic functional groups, and a carboxylic acid group or a phosphonic acid group is preferred.

[0076] (Carboxylic Acid) The carboxylic acid may be a monocarboxylic acid having one carboxyl group, or a polycarboxylic acid having two or more carboxyl groups. In terms of superior cleaning performance, the carboxylic acid preferably has two or more carboxyl groups, more preferably has 2 to 7 carboxyl groups, and even more preferably has 3 to 6 carboxyl groups.

[0077] Carboxylic acids include, for example, aminopolycarboxylic acids, hydroxycarboxylic acids, amino acids, and aliphatic carboxylic acids.

[0078] -Aminopolycarboxylic acid- An aminopolycarboxylic acid is a compound having one or more amino groups and two or more carboxyl groups as coordinating groups in the molecule. Examples of aminopolycarboxylic acids include diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetraacetic acid (EDTA), aspartic acid, glutamic acid, butylenediaminetetraacetic acid, ethylenediaminetetrapropionic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, propylenediaminetetraacetic acid, trans-1,2-diaminocyclohexanetetraacetic acid (CyDTA), ethylenediaminediacetic acid, ethylenediaminedipropionic acid, 1,6-hexamethylene-diamine-N,N,N',N'-tetraacetic acid, N,N-bis(2-hydroxybenzyl)ethylenediamine-N,N-diacetic acid, diaminopropanetetraacetic acid, 1,4,7,10-tetraazacyclododecane-tetraacetic acid, diaminopropanoltetraacetic acid, (hydroxyethyl)ethylenediaminetriacetic acid, and iminodiacetic acid (IDA). Of these, DTPA, EDTA, CyDTA, or IDA is preferred, and DTPA or EDTA is more preferred.

[0079] -Hydroxy carboxylic acid- Hydroxycarboxylic acids are compounds that have one or more hydroxyl groups and one or more carboxyl groups in the molecule. The cleaning liquid preferably contains a hydroxycarboxylic acid, in that the effect of the present invention is more excellent. Examples of hydroxycarboxylic acids include citric acid, malic acid, glycolic acid, gluconic acid, heptonic acid, tartaric acid, and lactic acid, with citric acid, gluconic acid, glycolic acid, malic acid, or tartaric acid being preferred, citric acid or gluconic acid being more preferred, and citric acid being even more preferred.

[0080] -amino acid- An amino acid is a compound that has one carboxyl group and one or more amino groups in the molecule. Examples of amino acids include glycine, serine, α-alanine (2-aminopropionic acid), β-alanine (3-aminopropionic acid), lysine, leucine, isoleucine, cysteine, methionine, ethionine, threonine, tryptophan, tyrosine, valine, histidine, histidine derivatives, asparagine, glutamine, arginine, proline, phenylalanine, compounds described in paragraphs

[0021] to

[0023] of JP 2016-086094 A, and salts thereof. In addition, compounds described in JP 2015-165561 A and JP 2015-165562 A, etc., can be used as histidine derivatives, and the contents of these are incorporated herein by reference. Examples of the salt include alkali metal salts such as sodium salts and potassium salts, ammonium salts, carbonates, and acetates. Among these, sulfur-containing amino acids that contain a sulfur atom are preferred. Examples of sulfur-containing amino acids include cystine, cysteine, ethionine, and methionine, with cystine or cysteine ​​being preferred.

[0081] -Aliphatic carboxylic acids- Examples of aliphatic carboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, and maleic acid, with adipic acid being preferred. In particular, the use of adipic acid can significantly improve the performance (cleaning performance and corrosion prevention) of the cleaning solution compared to other chelating agents. Although the detailed mechanism of such a unique effect of adipic acid is unclear, it is expected to be due to the fact that the number of carbon chains in the alkylene group is particularly excellent in hydrophilicity and hydrophobicity in relation to the two carboxyl groups, and forms a stable ring structure when complexed with a metal.

[0082] Examples of carboxylic acids other than the above aminopolycarboxylic acids, hydroxycarboxylic acids, amino acids, and aliphatic carboxylic acids include monocarboxylic acids. Examples of monocarboxylic acids include lower (C1-4) aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, and butyric acid.

[0083] The carboxylic acid is preferably an aminopolycarboxylic acid or a hydroxycarboxylic acid, more preferably DTPA, EDTA, or citric acid.

[0084] The carboxylic acids may be used alone or in combination of two or more. The content of the carboxylic acid in the cleaning solution is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the cleaning solution. The lower limit is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the cleaning solution. The content of the carboxylic acid is preferably 40% by mass or less, more preferably 10% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to obtain a more excellent effect of the present invention. Although there is no particular lower limit, the content is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent.

[0085] (phosphonic acid) The phosphonic acid may be a monophosphonic acid having one phosphonic acid group, or a polyphosphonic acid having two or more phosphonic acid groups. In terms of superior cleaning performance, a polyphosphonic acid having two or more phosphonic acid groups is preferred.

[0086] Examples of polyphosphonic acids include compounds represented by the following formula (P1), compounds represented by formula (P2), and compounds represented by formula (P3).

[0087] [ka]

[0088] In the formula, X represents a hydrogen atom or a hydroxyl group, R 11 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0089] R in formula (P1) 11The alkyl group having 1 to 10 carbon atoms represented by the following formula may be linear, branched or cyclic. R in formula (P1) 11 As the group, an alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group, an ethyl group, an n-propyl group, or an isopropyl group is more preferable. In the specific examples of alkyl groups described in this specification, n- represents a normal form. X in formula (P1) is preferably a hydroxyl group.

[0090] The compound represented by formula (P1) is preferably 1-hydroxyethylidene-1,1'-diphosphonic acid (HEDP), ethylidene diphosphonic acid, 1-hydroxypropylidene-1,1'-diphosphonic acid, or 1-hydroxybutylidene-1,1'-diphosphonic acid, and more preferably HEDP.

[0091] [ka]

[0092] In the formula, Q is a hydrogen atom or R 13 -PO3H2, R 12 and R 13 each independently represents an alkylene group; Y represents a hydrogen atom; -R 13 -PO3H2, or a group represented by the following formula (P4).

[0093] [ka]

[0094] In the formula, Q and R 13 Q and R in formula (P2) 13 is the same as:

[0095] In formula (P2), R 12 Examples of the alkylene group represented by the following formula include linear or branched alkylene groups having 1 to 12 carbon atoms. R 12The alkylene group represented by the formula (I) is preferably a linear or branched alkylene group having 1 to 6 carbon atoms, more preferably a linear or branched alkylene group having 1 to 4 carbon atoms, and further preferably an ethylene group. In formulas (P2) and (P4), R 13 Examples of the alkylene group represented by the formula (I) include linear or branched alkylene groups having 1 to 10 carbon atoms, preferably linear or branched alkylene groups having 1 to 4 carbon atoms, more preferably a methylene group or ethylene group, and still more preferably a methylene group. Q in the formulas (P2) and (P4) is -R 13 -PO3H2 is preferred. Y in formula (P2) is -R 13 -PO3H2 or a group represented by formula (P4) is preferred, and a group represented by formula (P4) is more preferred.

[0096] As the compound represented by formula (P2), ethylaminobis(methylene phosphonic acid), dodecylaminobis(methylene phosphonic acid), nitrilotris(methylene phosphonic acid) (NTPO), ethylenediaminebis(methylene phosphonic acid) (EDDPO), 1,3-propylenediaminebis(methylene phosphonic acid), ethylenediaminetetra(methylene phosphonic acid) (EDTPO), ethylenediaminetetra(ethylene phosphonic acid), 1,3-propylenediaminetetra(methylene phosphonic acid) (PDTMP), 1,2-diaminopropanetetra(methylene phosphonic acid), or 1,6-hexamethylenediaminetetra(methylene phosphonic acid) is preferred.

[0097] [ka]

[0098] In the formula, R 14 and R 15 each independently represents an alkylene group having 1 to 4 carbon atoms, n represents an integer of 1 to 4, Z 1 ~Z 4 and n Z's 5At least four of the groups represent alkyl groups having a phosphonic acid group, and the remainder represent alkyl groups.

[0099] In formula (P3), R 14 and R 15 The alkylene group having 1 to 4 carbon atoms represented by the formula (I) may be either linear or branched. 14 and R 15 Examples of the alkylene group having 1 to 4 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propylene group, a trimethylene group, an ethylmethylene group, a tetramethylene group, a 2-methylpropylene group, a 2-methyltrimethylene group, and an ethylethylene group, with an ethylene group being preferred. In formula (P3), n is preferably 1 or 2.

[0100] Z in formula (P3) 1 ~Z 5 and the alkyl group in the alkyl group having a phosphonic acid group are, for example, linear or branched alkyl groups having 1 to 4 carbon atoms, and a methyl group is preferred. Z 1 ~Z 5 The number of phosphonic acid groups in the alkyl group having a phosphonic acid group represented by the following formula (I) is preferably one or two, and more preferably one. Z 1 ~Z 5 Examples of the alkyl group having a phosphonic acid group represented by the formula (I) include linear or branched alkyl groups having 1 to 4 carbon atoms and having one or two phosphonic acid groups. A (mono)phosphonomethyl group or a (mono)phosphonoethyl group is preferable, and a (mono)phosphonomethyl group is more preferable. Z in formula (P3) 1 ~Z 5 As for Z, 1 ~Z 4 and n Z's 5 It is preferable that all of the above are alkyl groups having a phosphonic acid group.

[0101] The compound represented by formula (P3) is preferably diethylenetriaminepenta(methylenephosphonic acid) (DEPPO), diethylenetriaminepenta(ethylenephosphonic acid), triethylenetetraminehexa(methylenephosphonic acid), or triethylenetetraminehexa(ethylenephosphonic acid).

[0102] As the polyphosphonic acid used in the cleaning solution, not only the compound represented by the above formula (P1), the compound represented by the formula (P2), and the compound represented by the formula (P3), but also the compounds described in paragraphs

[0026] to

[0036] of the specification of WO 2018 / 020878, and the compounds ((co)polymers) described in paragraphs

[0031] to

[0046] of the specification of WO 2018 / 030006 can be used, the contents of which are incorporated herein by reference.

[0103] The number of phosphonic acid groups in the phosphonic acid is preferably 2 to 5, more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the phosphonic acid is preferably 12 or less, more preferably 10 or less, and even more preferably 8 or less. There is no particular lower limit, and the number is preferably 1 or more. As the phosphonic acid, the compounds exemplified as specific preferred examples for the compound represented by the above formula (P1), the compound represented by the formula (P2), and the compound represented by the formula (P3) are preferred, and HEDP is more preferred.

[0104] The phosphonic acids may be used alone or in combination of two or more. The content of phosphonic acid in the cleaning solution is not particularly limited, but is preferably 2% by mass or less, more preferably 1% by mass or less, based on the total mass of the cleaning solution. The lower limit is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the cleaning solution. The content of phosphonic acid is preferably 40% by mass or less, more preferably 10% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to obtain a more excellent effect of the present invention. Although there is no particular lower limit, the content is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent.

[0105] The organic acid is preferably at least one selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, and phosphonic acids, and more preferably DTPA, EDTA, citric acid, or HEDP.

[0106] The organic acid preferably has a low molecular weight. Specifically, the molecular weight of the organic acid is preferably 600 or less, more preferably 450 or less, and even more preferably 300 or less. There is no particular lower limit, but a molecular weight of 85 or more is preferable. The number of carbon atoms in the organic acid is preferably 15 or less, more preferably 12 or less, and even more preferably 8 or less. There is no particular lower limit, but a number of carbon atoms of 2 or more is preferable.

[0107] The organic acids may be used alone or in combination of two or more. In terms of excellent cleaning performance, it is preferable that the cleaning liquid contains two or more organic acids. The content of the organic acid in the cleaning solution is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the cleaning solution. The lower limit is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the cleaning solution. The content of the organic acid is preferably 40% by mass or less, more preferably 10% by mass or less, based on the total mass of the components in the cleaning solution excluding the solvent, in order to obtain a more excellent effect of the present invention. Although there is no particular lower limit, the content is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, based on the total mass of the components in the cleaning solution excluding the solvent.

[0108] <Corrosion inhibitor> The cleaning liquid may contain a corrosion inhibitor. As the anticorrosive agent, a component different from the above-mentioned components is preferable. Examples of the anticorrosive agent include anticorrosive agents that do not have a reducing action, such as heterocyclic compounds having a heterocyclic structure and phosphate surfactants; anticorrosive agents that have a reducing action, such as biguanide compounds, ascorbic acid compounds, hydroxylamine compounds, catechol compounds, hydrazide compounds, reducing sulfur compounds, and hydroxycarboxylic acids, and derivatives thereof. Among these, anticorrosive agents that do not have a reducing action are preferred, and heterocyclic compounds or phosphate surfactants are more preferred. A corrosion inhibitor with a reducing effect is an agent that has an oxidizing effect and reduces the OH contained in the cleaning solution. - A compound that has the function of oxidizing ions or dissolved oxygen, and is also called an oxygen scavenger.

[0109] -Heterocyclic compounds- Heterocyclic compounds are compounds that have a heterocyclic structure in the molecule. The heterocyclic structure of the heterocyclic compounds is not particularly limited, and examples thereof include compounds that are heterocyclic rings (nitrogen-containing heterocyclic rings) in which at least one of the atoms that constitute the ring is a nitrogen atom, and are not limited to the above-mentioned components. Examples of the heterocyclic compound having a nitrogen-containing heterocycle include nitrogen-containing heteroaromatic compounds such as azole compounds.

[0110] An azole compound is a compound having at least one nitrogen atom and a five-membered heterocyclic ring having aromaticity. The number of nitrogen atoms contained in the five-membered hetero ring of the azole compound is not particularly limited, and is preferably 1 to 4, and more preferably 1 to 3. The azole compound may have a substituent on the 5-membered hetero ring. Examples of such a substituent include a hydroxyl group, a carboxyl group, a mercapto group, an amino group, an alkyl group having 1 to 4 carbon atoms which may have an amino group, and a 2-imidazolyl group.

[0111] Examples of the azole compound include an imidazole compound in which one of the atoms constituting the azole ring is a nitrogen atom, a pyrazole compound in which two of the atoms constituting the azole ring are nitrogen atoms, a thiazole compound in which one of the atoms constituting the azole ring is a nitrogen atom and the other is a sulfur atom, a triazole compound in which three of the atoms constituting the azole ring are nitrogen atoms, and a tetrazole compound in which four of the atoms constituting the azole ring are nitrogen atoms.

[0112] Examples of imidazole compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 5-methylimidazole, 1,2-dimethylimidazole, 2-mercaptoimidazole, 4,5-dimethyl-2-mercaptoimidazole, 4-hydroxyimidazole, 2,2'-biimidazole, 4-imidazolecarboxylic acid, histamine, benzimidazole, and purine bases (such as adenine).

[0113] Examples of pyrazole compounds include 3-amino-5-methylpyrazole, pyrazole, 4-pyrazole carboxylic acid, 1-methylpyrazole, 3-methylpyrazole, 3-amino-5-hydroxypyrazole, 3-aminopyrazole, and 4-aminopyrazole.

[0114] Thiazole compounds include, for example, 2,4-dimethylthiazole, benzothiazole, and 2-mercaptobenzothiazole.

[0115] Examples of triazole compounds include 1,2,4-triazole, 1-bis(2-hydroxyethyl)aminomethyl-5-methyl-1H-benzotriazole, 1-bis(2-hydroxyethyl)aminomethyl-4-methyl-1H-benzotriazole, 3-methyl-1,2,4-triazole, 3-amino-1,2,4-triazole, 1,2,3-triazole, 1-methyl-1,2,3-triazole, benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxybenzotriazole, and 5-methylbenzotriazole.

[0116] Examples of tetrazole compounds include 1H-tetrazole (1,2,3,4-tetrazole), 5-methyl-1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, and 1-(2-dimethylaminoethyl)-5-mercaptotetrazole.

[0117] The azole compound is preferably an imidazole compound, a pyrazole compound, a triazole compound, or a tetrazole compound, more preferably a pyrazole compound or a triazole compound, and even more preferably 3-amino-5-methylpyrazole, 1,2,4-triazole, 1-bis(2-hydroxyethyl)aminomethyl-5-methyl-1H-benzotriazole, or 1-bis(2-hydroxyethyl)aminomethyl-4-methyl-1H-benzotriazole.

[0118] -Phosphate ester surfactants- Examples of the phosphate surfactant include phosphate esters (alkyl ether phosphate esters and aryl ether phosphate esters), polyoxyalkylene ether phosphate esters (polyoxyalkylene alkyl ether phosphate esters and polyoxyalkylene aryl ether phosphate esters), and salts thereof. Phosphate esters and polyoxyalkylene ether phosphate esters usually include both monoesters and diesters, but monoesters or diesters can be used alone. Examples of salts of the phosphate ester surfactant include sodium salts, potassium salts, ammonium salts, and organic amine salts. The alkyl group contained in the phosphate ester and polyoxyalkylene ether phosphate ester is not particularly limited, but is preferably an alkyl group having 2 to 24 carbon atoms, more preferably an alkyl group having 6 to 22 carbon atoms, and even more preferably an alkyl group having 10 to 20 carbon atoms. The aryl group contained in the phosphate ester and polyoxyalkylene ether phosphate ester is not particularly limited, but is preferably an aryl group having 6 to 14 carbon atoms which may have an alkyl group, and more preferably a phenyl group which may have an alkyl group. The divalent alkylene group in the polyoxyalkylene ether phosphate is not particularly limited, but is preferably an alkylene group having 2 to 6 carbon atoms, more preferably an ethylene group. The number of repetitions of the oxyalkylene group in the polyoxyalkylene ether phosphate is preferably 1 to 12, more preferably 3 to 10.

[0119] Examples of the phosphate surfactant include octyl phosphate, lauryl phosphate, tridecyl phosphate, myristyl phosphate, cetyl phosphate, stearyl phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene lauryl ether phosphate, polyoxyethylene tridecyl ether phosphate, and polyoxyethylene dimethylphenyl ether phosphate. Among these, the phosphate surfactant is preferably polyoxyethylene dimethylphenyl ether phosphate.

[0120] As the phosphate ester surfactant, the compounds described in paragraphs

[0012] to

[0019] of JP2011-040502A can also be used, the contents of which are incorporated herein by reference.

[0121] -Biguanide compounds- The biguanide compound is a compound having a biguanide group or a salt thereof. The number of biguanide groups that the biguanide compound has is not particularly limited, and the biguanide compound may have a plurality of biguanide groups. Examples of the biguanide compound include the compounds described in paragraphs

[0034] to

[0055] of JP2017-504190A, the contents of which are incorporated herein by reference.

[0122] Examples of compounds having a biguanide group include ethylene dibiguanide, propylene dibiguanide, tetramethylene dibiguanide, pentamethylene dibiguanide, hexamethylene dibiguanide, heptamethylene dibiguanide, octamethylene dibiguanide, 1,1'-hexamethylenebis(5-(p-chlorophenyl)biguanide) (chlorhexidine), 2-(benzyloxymethyl)pentane-1,5-bis(5-hexylbiguanide), 2-(phenyl)-1,5-bis(5-phenyl)biguanide, ...

[0033] Preferred are 3-(phenylthio)hexane-1,6-bis(5-hexylbiguanide), 3-(phenylthio)hexane-1,6-bis(5-cyclohexylbiguanide), 3-(benzylthio)hexane-1,6-bis(5-hexylbiguanide), or 3-(benzylthio)hexane-1,6-bis(5-cyclohexylbiguanide), with chlorhexidine being more preferred. As the salt of the compound having a biguanide group, hydrochloride, acetate or gluconate is preferred, and gluconate is more preferred. A preferred biguanide compound is chlorhexidine gluconate (CHG).

[0123] -Ascorbic acid compounds- The ascorbic acid compound means at least one selected from the group consisting of ascorbic acid, ascorbic acid derivatives, and salts thereof. Examples of ascorbic acid derivatives include ascorbic acid phosphate and ascorbic acid sulfate. The ascorbic acid compound is preferably ascorbic acid, ascorbic acid phosphate, or ascorbic acid sulfate, and more preferably ascorbic acid.

[0124] -Hydroxylamine compounds- The hydroxylamine compound means at least one selected from the group consisting of hydroxylamine (NH2OH), hydroxylamine derivatives, and salts thereof. The hydroxylamine derivative means a compound in which at least one organic group is substituted on hydroxylamine (NH2OH). The salt of hydroxylamine or a hydroxylamine derivative may be an inorganic acid salt or an organic acid salt of hydroxylamine or a hydroxylamine derivative. The salt of hydroxylamine or a hydroxylamine derivative is preferably a salt with an inorganic acid formed by combining at least one nonmetal selected from the group consisting of Cl, S, N, and P with hydrogen, and more preferably a hydrochloride, sulfate, or nitrate.

[0125] Examples of the hydroxylamine compound include a compound represented by the following formula (3) or a salt thereof.

[0126] [ka]

[0127] In formula (3), R 5 and R 6 each independently represents a hydrogen atom or an organic group.

[0128] R 5 and R 6 The organic group represented by the formula: is preferably an alkyl group having a carbon number of 1 to 6. The alkyl group having a carbon number of 1 to 6 may be linear, branched, or cyclic. Also, R 5 and R 6 At least one of them is preferably an organic group (more preferably an alkyl group having 1 to 6 carbon atoms). The alkyl group having 1 to 6 carbon atoms is preferably an ethyl group or an n-propyl group, and more preferably an ethyl group.

[0129] Examples of hydroxylamine compounds include hydroxylamine, O-methylhydroxylamine, O-ethylhydroxylamine, N-methylhydroxylamine, N,N-dimethylhydroxylamine, N,O-dimethylhydroxylamine, N-ethylhydroxylamine, N,N-diethylhydroxylamine, N,O-diethylhydroxylamine, O,N,N-trimethylhydroxylamine, N,N-dicarboxyethylhydroxylamine, and N,N-disulfoethylhydroxylamine. Of these, N-ethylhydroxylamine, N,N-diethylhydroxylamine (DEHA), or Nn-propylhydroxylamine is preferred, and DEHA is more preferred.

[0130] -Catechol compounds- The catechol compound means at least one selected from the group consisting of pyrocatechol (benzene-1,2-diol) and catechol derivatives. The catechol derivative means a compound in which at least one substituent is substituted on pyrocatechol. The substituent of the catechol derivative includes a hydroxyl group, a carboxyl group, a carboxylate group, a sulfo group, a sulfonate group, an alkyl group (preferably having 1 to 6 carbon atoms, more preferably having 1 to 4 carbon atoms), and an aryl group (preferably a phenyl group). The carboxyl group and the sulfo group that the catechol derivative has as a substituent may be a salt with a cation. The alkyl group and the aryl group that the catechol derivative has as a substituent may further have a substituent. Examples of catechol compounds include pyrocatechol, 4-tert-butylcatechol, pyrogallol, gallic acid, methyl gallate, 1,2,4-benzenetriol, and tiron.

[0131] -Hydrazide compounds- The hydrazide compound means a compound in which the hydroxyl group of an acid is replaced with a hydrazino group (-NH-NH2), and its derivatives (compounds in which the hydrazino group is substituted with at least one substituent). The hydrazide compound may have two or more hydrazino groups. Examples of the hydrazide compound include carboxylic acid hydrazide and sulfonic acid hydrazide, and carbohydrazide (CHZ) is preferred.

[0132] -Reduced sulfur compounds- The reducing sulfur compound is not particularly limited as long as it contains a sulfur atom and functions as a reducing agent, and examples thereof include cysteine, mercaptosuccinic acid, dithiodiglycerol, bis(2,3-dihydroxypropylthio)ethylene, sodium 3-(2,3-dihydroxypropylthio)-2-methyl-propylsulfonate, 1-thioglycerol, sodium 3-mercapto-1-propanesulfonate, 2-mercaptoethanol, thioglycolic acid, and 3-mercapto-1-propanol. Among these, compounds having an SH group (mercapto compounds) are preferred, with cysteine, 1-thioglycerol, sodium 3-mercapto-1-propanesulfonate, 2-mercaptoethanol, 3-mercapto-1-propanol, or thioglycolic acid being more preferred, and cysteine ​​being even more preferred.

[0133] -Other corrosion inhibitors- The cleaning liquid may contain other anticorrosive agents in addition to the above-mentioned components. Other corrosion inhibitors include, for example, sugars such as fructose, glucose, and ribose; polyols such as ethylene glycol, propylene glycol, and glycerin; polyvinylpyrrolidone, cyanuric acid, barbituric acid and its derivatives, glucuronic acid, squaric acid, α-keto acids, adenosine and its derivatives, phenanthroline, resorcinol, hydroquinone, nicotinamide and its derivatives, flavonol and its derivatives, anthocyanin and its derivatives, and combinations thereof.

[0134] The corrosion inhibitor preferably contains a heterocyclic compound or a phosphate ester surfactant, and more preferably contains at least one selected from the group consisting of a tetrazole compound, a triazole compound, an imidazole compound, a pyrazole compound, and derivatives thereof.

[0135] The anticorrosive agent may be used alone or in combination of two or more kinds. In terms of achieving better corrosion prevention performance, the cleaning liquid preferably contains two or more types of corrosion inhibitors, and more preferably contains three or more types of corrosion inhibitors. The content of the anticorrosive agent is preferably from 0.01 to 20 mass %, more preferably from 0.1 to 10 mass %, and further preferably from 0.3 to 5 mass %, based on the total mass of the cleaning liquid. The content of the anticorrosive agent is preferably 0.1 to 40 mass %, more preferably 1 to 30 mass %, and even more preferably 5 to 20 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0136] <Surfactant> The cleaning liquid may contain a surfactant other than the above components. The surfactant is not particularly limited as long as it is a compound having a hydrophilic group and a hydrophobic group (lipophilic group) in the molecule. Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, with anionic surfactants or nonionic surfactants being preferred.

[0137] Surfactants often have a hydrophobic group selected from an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof. The hydrophobic group of the surfactant is not particularly limited. In particular, when the hydrophobic group includes an aromatic hydrocarbon group, the carbon number of the aromatic hydrocarbon group is preferably 6 or more, more preferably 10 or more. The upper limit of the carbon number of the aromatic hydrocarbon group is not particularly limited, but is preferably 20 or less, more preferably 18 or less. When the hydrophobic group does not contain an aromatic hydrocarbon group and is composed only of an aliphatic hydrocarbon group, the carbon number of the aliphatic hydrocarbon group is preferably 10 or more, more preferably 12 or more, and even more preferably 16 or more. There is no upper limit to the carbon number of the aliphatic hydrocarbon group, but it is preferably 20 or less, and more preferably 18 or less.

[0138] (anionic surfactant) Examples of the anionic surfactant contained in the cleaning solution include phosphonic acid surfactants having a phosphonic acid group, sulfonic acid surfactants having a sulfo group, carboxylic acid surfactants having a carboxyl group, and sulfate ester surfactants having a sulfate ester group, each of which has a hydrophilic group (acid group). Among these, it is preferable that the cleaning solution contains an anionic surfactant, since the effect of the present invention is more excellent.

[0139] -Phosphonic acid surfactants- Examples of phosphonic acid surfactants include alkylphosphonic acid and polyvinylphosphonic acid, and also include aminomethylphosphonic acid, as described in JP2012-057108A.

[0140] -Sulfonic acid surfactants- Examples of sulfonic acid surfactants include alkyl sulfonic acids, alkyl benzene sulfonic acids, alkyl naphthalene sulfonic acids, alkyl diphenyl ether disulfonic acids, alkyl methyl taurines, sulfosuccinic acid diesters, polyoxyalkylene alkyl ether sulfonic acids, and salts thereof.

[0141] The monovalent alkyl group of the sulfonic acid surfactant is not particularly limited, but is preferably an alkyl group having 10 or more carbon atoms, and more preferably an alkyl group having 12 or more carbon atoms. The upper limit of the number of carbon atoms of the alkyl group is not particularly limited, but is preferably 24 or less. The alkylene group in the polyoxyalkylene alkyl ether sulfonic acid is not particularly limited, but is preferably an ethylene group or a 1,2-propanediyl group. The number of repetitions of the oxyalkylene group in the polyoxyalkylene alkyl ether sulfonic acid is preferably 1 to 12, more preferably 1 to 6.

[0142] Specific examples of sulfonic acid surfactants include hexanesulfonic acid, octanesulfonic acid, decanesulfonic acid, dodecanesulfonic acid, toluenesulfonic acid, cumenesulfonic acid, octylbenzenesulfonic acid, dodecylbenzenesulfonic acid (DBSA), dinitrobenzenesulfonic acid (DNBSA), and lauryldodecylphenyletherdisulfonic acid (LDPEDSA). Among these, sulfonic acid surfactants having an alkyl group with 10 or more carbon atoms are preferred, sulfonic acid surfactants having an alkyl group with 12 or more carbon atoms are more preferred, and DBSA is even more preferred.

[0143] -Carboxylic acid surfactants- Examples of the carboxylic acid surfactant include alkyl carboxylic acids, alkyl benzene carboxylic acids, and polyoxyalkylene alkyl ether carboxylic acids, and salts thereof. The alkyl group contained in the carboxylic acid surfactant is not particularly limited, but is preferably an alkyl group having 7 to 25 carbon atoms, and more preferably an alkyl group having 11 to 17 carbon atoms. The alkylene group in the polyoxyalkylene alkyl ether carboxylic acid is not particularly limited, but is preferably an ethylene group or a 1,2-propanediyl group. The repeat number of the oxyalkylene group in the polyoxyalkylene alkyl ether carboxylic acid is preferably 1 to 12, more preferably 1 to 6.

[0144] Specific examples of carboxylic acid surfactants include lauric acid, myristic acid, palmitic acid, stearic acid, polyoxyethylene lauryl ether acetic acid, and polyoxyethylene tridecyl ether acetic acid.

[0145] -Sulfate ester surfactants- Examples of sulfate surfactants include sulfates (alkyl ether sulfates), polyoxyalkylene ether sulfates, and salts thereof. The alkyl group contained in the sulfate ester and polyoxyalkylene ether sulfate ester is not particularly limited, but is preferably an alkyl group having 2 to 24 carbon atoms, and more preferably an alkyl group having 6 to 18 carbon atoms. The alkylene group in the polyoxyalkylene ether sulfate is not particularly limited, but is preferably an ethylene group or a 1,2-propanediyl group. The repeat number of the oxyalkylene group in the polyoxyalkylene ether sulfate is preferably 1 to 12, more preferably 1 to 6. Specific examples of sulfate surfactants include lauryl sulfate, myristyl sulfate, and polyoxyethylene lauryl ether sulfate.

[0146] (Nonionic surfactant) Examples of nonionic surfactants include polyoxyalkylene alkyl ethers (e.g., polyoxyethylene stearyl ether, etc.), polyoxyalkylene alkenyl ethers (e.g., polyoxyethylene oleyl ether, etc.), polyoxyethylene alkyl phenyl ethers (e.g., polyoxyethylene nonyl phenyl ether, etc.), polyoxyalkylene glycols (e.g., polyoxypropylene polyoxyethylene glycol, etc.), polyoxyalkylene monoalkylates (monoalkyl fatty acid ester polyoxyalkylenes) (e.g., polyoxyethylene monostearate, polyoxyethylene monooleate, and other polyoxyalkylenes). ethylene monoalkylates), polyoxyalkylene dialkylates (dialkyl fatty acid ester polyoxyalkylenes) (for example, polyoxyethylene dialkylates such as polyoxyethylene distearate and polyoxyethylene diolate), bispolyoxyalkylene alkylamides (for example, bispolyoxyethylenestearylamide, etc.), sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylamines, glycerin fatty acid esters, oxyethylene oxypropylene block copolymers, acetylene glycol surfactants, and acetylene polyoxyethylene oxides.

[0147] (Cationic Surfactant) Examples of cationic surfactants include primary to tertiary alkylamine salts (e.g., monostearyl ammonium chloride, distearyl ammonium chloride, and tristearyl ammonium chloride), and modified aliphatic polyamines (e.g., polyethylene polyamine).

[0148] (Amphoteric surfactant) Examples of the amphoteric surfactant include carboxybetaines (e.g., alkyl-N,N-dimethylaminoacetate betaine, alkyl-N,N-dihydroxyethylaminoacetate betaine, etc.), sulfobetaines (e.g., alkyl-N,N-dimethylsulfonioethylammonium betaine, etc.), and imidazolinium betaines (e.g., 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, etc.).

[0149] As the surfactant, the compounds described in paragraphs

[0092] to

[0096] of JP-A-2015-158662, paragraphs

[0045] to

[0046] of JP-A-2012-151273, and paragraphs

[0014] to

[0020] of JP-A-2009-147389 can also be incorporated herein, and the contents thereof are incorporated into this specification.

[0150] The surfactant may be used alone or in combination of two or more. When the cleaning liquid contains a surfactant, its content is preferably 0.01 to 5.0% by mass, more preferably 0.05 to 2.0% by mass, based on the total mass of the cleaning liquid. Also, the content of the surfactant is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, based on the total mass of the components excluding the solvent in the cleaning liquid.

[0151] <pH adjuster> The cleaning liquid may contain a pH adjuster to adjust and maintain the pH of the cleaning liquid. Examples of the pH adjuster include basic compounds and acidic compounds other than the above components.

[0152] - Basic compound - Examples of the basic compound include inorganic base compounds other than the above-described organic base compounds. Examples of the inorganic base compound include alkali metal hydroxides, alkaline earth metal hydroxides, and ammonia. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide. Examples of alkaline earth metal hydroxides include calcium hydroxide, strontium hydroxide, and barium hydroxide.

[0153] These basic compounds may be commercially available or may be appropriately synthesized by known methods.

[0154] -Acidic compounds- Examples of the acidic compound include inorganic acids. Examples of inorganic acids include hydrochloric acid, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, phosphoric acid, boric acid, and hexafluorophosphoric acid. In addition, salts of inorganic acids may be used, such as ammonium salts of inorganic acids, more specifically, ammonium chloride, ammonium sulfate, ammonium sulfite, ammonium nitrate, ammonium nitrite, ammonium phosphate, ammonium borate, and ammonium hexafluorophosphate. As the inorganic acid, sulfuric acid, phosphoric acid, or a phosphate is preferred, and sulfuric acid or phosphoric acid is more preferred.

[0155] As the acidic compound, a salt of an acidic compound may be used as long as it becomes an acid or an acid ion (anion) in an aqueous solution. The acidic compound to be used may be a commercially available product, or may be appropriately synthesized by a known method.

[0156] The pH adjusters may be used alone or in combination of two or more. When the cleaning solution contains a pH adjuster, its content is selected depending on the types and amounts of other components and the desired pH of the cleaning solution, but is preferably 0.01 to 3 mass %, and more preferably 0.05 to 1 mass %, based on the total mass of the cleaning solution.

[0157] <Additives> The cleaning liquid may contain additives other than the above components. Examples of the additives include polymers other than the above components, chelating agents, fluorine compounds, and organic solvents, with polymers being preferred.

[0158] -Polymer- The cleaning solution may include a polymer. The polymer is a component different from the above-mentioned components. The weight average molecular weight of the polymer is preferably at least 200, more preferably at least 1000, and even more preferably at least 2000. There is no particular upper limit, but the weight average molecular weight is preferably at most 1,000,000, and more preferably at most 500,000. In particular, when the polymer is a water-soluble polymer described below, the weight-average molecular weight of the water-soluble polymer is preferably at least 200, more preferably at least 1500, and even more preferably at least 3000. There is no upper limit to the weight-average molecular weight of the water-soluble polymer, and it is, for example, 1,500,000 or less, preferably 1,200,000 or less, more preferably 1,000,000 or less, and even more preferably 10,000 or less. The polymer preferably contains at least one selected from the group consisting of polymer A having a weight average molecular weight of 500 or more and less than 2000, and polymer B having a weight average molecular weight of 2000 or more. There is no particular upper limit to the molecular weight of polymer B, but it is preferably 1,000,000 or less, more preferably 500,000 or less. In this specification, the term "weight average molecular weight" refers to the weight average molecular weight calculated as polyethylene glycol, measured by GPC (gel permeation chromatography). The polymer preferably has a carboxyl group or an acid anhydride group (-CO-O-CO-). More specifically, the polymer preferably has a repeating unit having a carboxyl group (such as a repeating unit derived from (meth)acrylic acid) or a repeating unit having an acid anhydride group. The content of the repeating unit having a carboxyl group or the repeating unit having an acid anhydride group is preferably 30 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 85 to 100% by mass, based on the total mass of the polymer. Among these, polymer B having a carboxyl group or an acid anhydride group is preferred.

[0159] It is also preferred that the polymer is a water-soluble polymer. The term "water-soluble polymer" refers to a compound in which two or more repeating units are linked in a linear or network pattern via covalent bonds, and which has a mass that dissolves in 100 g of water at 20°C of 0.1 g or more.

[0160] Examples of the water-soluble polymer include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polystyrene sulfonic acid, and salts thereof; copolymers of monomers such as styrene, α-methylstyrene, and / or 4-methylstyrene with acid monomers such as (meth)acrylic acid and / or maleic acid, and salts thereof; polymers having repeating units having aromatic hydrocarbon groups, which are obtained by condensing benzenesulfonic acid and / or naphthalenesulfonic acid with formalin, and salts thereof; vinyl-based synthetic polymers such as polyvinyl alcohol, polyoxyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyacrylamide, polyvinylformamide, polyethyleneimine, polyvinyloxazoline, polyvinylimidazole, and polyallylamine; and modified products of natural polysaccharides such as hydroxyethyl cellulose, carboxymethyl cellulose, and processed starch.

[0161] The water-soluble polymer may be a homopolymer or a copolymer obtained by copolymerizing two or more kinds of monomers. Examples of such monomers include monomers selected from the group consisting of monomers having a carboxyl group, monomers having a sulfonic acid group, monomers having a hydroxyl group, monomers having a polyethylene oxide chain, monomers having an amino group, and monomers having a heterocycle. The water-soluble polymer is also preferably a polymer consisting essentially of structural units derived from monomers selected from the above group. For example, the content of structural units derived from monomers selected from the above group relative to the mass of the polymer is preferably 95 to 100 mass%, more preferably 99 to 100 mass%.

[0162] The polymers may be used alone or in combination of two or more. When the cleaning liquid contains a polymer, the content thereof is preferably from 0.01 to 20 mass %, more preferably from 0.1 to 10 mass %, and further preferably from 0.3 to 5 mass %, based on the total mass of the cleaning liquid. The content of the polymer is preferably from 0.1 to 40% by mass, more preferably from 1 to 30% by mass, and even more preferably from 5 to 20% by mass, based on the total mass of the components excluding the solvent in the cleaning liquid. When the polymer content is within the above range, the polymer is appropriately adsorbed onto the surface of the substrate, which contributes to improving the corrosion prevention performance of the cleaning liquid, and also provides a good balance between the viscosity and / or cleaning performance of the cleaning liquid.

[0163] -Polyhydroxy compounds with molecular weight of 500 or more- The cleaning solution may contain a polyhydroxy compound having a molecular weight of 500 or more. The polyhydroxy compound is a component different from the above-mentioned components. The polyhydroxy compound is an organic compound having two or more (for example, 2 to 200) alcoholic hydroxyl groups in one molecule. The molecular weight of the polyhydroxy compound (weight average molecular weight when the compound has a molecular weight distribution) is 500 or more, and preferably 500 to 3,000.

[0164] Examples of the polyhydroxy compounds include polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol; oligosaccharides such as mannitol, cellotriose, gentianose, raffinose, melezitose, cerotetrose, and stachyose; and polysaccharides such as starch, glycogen, cellulose, xylose, chitin, and chitosan, and hydrolysates thereof.

[0165] Cyclodextrin is also a preferred example of the polyhydroxy compound. Cyclodextrin is a type of cyclic oligosaccharide in which a plurality of D-glucose units are bonded to each other via glycosidic bonds to form a cyclic structure, and is a compound in which five or more glucose units (for example, six to eight glucose units) are bonded. Examples of cyclodextrin include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, and among these, γ-cyclodextrin is preferred.

[0166] The above polyhydroxy compounds may be used alone or in combination of two or more kinds. When the cleaning liquid contains the polyhydroxy compound, the content thereof is preferably from 0.01 to 10 mass %, more preferably from 0.05 to 5 mass %, and further preferably from 0.1 to 3 mass %, based on the total mass of the cleaning liquid. The content of the polyhydroxy compound is preferably 0.1 to 40 mass %, more preferably 1 to 30 mass %, and even more preferably 5 to 20 mass %, based on the total mass of the components excluding the solvent in the cleaning liquid.

[0167] The chelating agent is not particularly limited as long as it is an organic acid having a chelating function as described above. Other chelating agents include inorganic acid-based chelating agents such as condensed phosphoric acid and its salts. Examples of condensed phosphoric acid and its salts include pyrophosphoric acid and its salts, metaphosphoric acid and its salts, tripolyphosphoric acid and its salts, and hexametaphosphoric acid and its salts.

[0168] Examples of the fluorine compound include compounds described in paragraphs

[0013] to

[0015] of JP-A-2005-150236, the contents of which are incorporated herein by reference.

[0169] As the organic solvent (sometimes referred to as a solvent), any known organic solvent can be used, but hydrophilic organic solvents such as alcohols and ketones are preferred.

[0170] The additives may be used alone or in combination of two or more. The content of the additive is not particularly limited, but the content is preferably from 0.01 to 20 mass %, more preferably from 0.1 to 10 mass %, and even more preferably from 0.3 to 5 mass %, based on the total mass of the cleaning liquid. The content of the additive is preferably 0.1 to 40 mass %, more preferably 1 to 30 mass %, and even more preferably 5 to 20 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0171] <Water> The cleaning liquid preferably contains water as a solvent. The type of water used in the cleaning solution is not particularly limited as long as it does not adversely affect the semiconductor substrate, and distilled water, deionized water, and pure water (ultrapure water) can be used. Pure water (ultrapure water) is preferred because it contains almost no impurities and has less effect on the semiconductor substrate during the manufacturing process of the semiconductor substrate. The content of water in the cleaning solution may be the remainder of the perhalogen acid, halogen acid, and the above-mentioned optional components. The content of water is, for example, preferably 1% by mass or more, more preferably 30% by mass or more, even more preferably 60% by mass or more, and particularly preferably 85% by mass or more, based on the total mass of the cleaning solution. There is no particular upper limit, but the content of water is preferably 99% by mass or less, more preferably 98% by mass or less, based on the total mass of the cleaning solution.

[0172] [Physical properties of cleaning solution] <Metal content> In the cleaning solution, the content (measured as an ion concentration) of metals (metal elements Fe, Co, Na, K, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the solution is preferably 5 mass ppm or less, more preferably 1 mass ppm or less. Since it is expected that even higher purity cleaning solutions will be required in the manufacture of cutting-edge semiconductor devices, it is more preferable that the metal content is lower than 1 mass ppm, that is, on the order of ppb or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. There is no particular lower limit, but 0 is preferable.

[0173] Methods for reducing the metal content include, for example, performing purification processes such as distillation and filtration using ion exchange resins or filters at the stage of raw materials used in producing the cleaning solution or at the stage after the cleaning solution is produced. As another method for reducing the metal content, a container that is less likely to elute impurities, as described below, may be used as a container for containing the raw materials or the produced cleaning solution. Another method is to provide a fluororesin lining on the inner wall of a pipe to prevent metal components from eluting from the pipe during production of the cleaning solution.

[0174] <Large particles> The cleaning solution may contain coarse particles, but the content of coarse particles is preferably low. Here, the term "coarse particles" refers to particles whose diameter (particle size) is 0.4 μm or more when the particle shape is considered as a sphere. Regarding the content of coarse particles in the cleaning solution, the content of particles having a particle diameter of 0.4 μm or more per 1 mL of the cleaning solution is preferably 1000 or less, more preferably 500 or less. The lower limit is not particularly limited, but may be 0. In addition, it is more preferable that the content of particles having a particle diameter of 0.4 μm or more measured by the following measurement method is equal to or less than the detection limit. The coarse particles contained in the cleaning solution include particles such as dust, dirt, organic solids, and inorganic solids that are contained as impurities in the raw materials, as well as particles such as dust, dirt, organic solids, and inorganic solids that are brought in as contaminants during the preparation of the cleaning solution and that ultimately exist as particles in the cleaning solution without dissolving. The content of coarse particles present in the cleaning liquid can be measured in the liquid phase using a commercially available measuring device that uses a laser as a light source for measuring particles in liquid by light scattering. Examples of a method for removing coarse particles include a purification process such as filtering, which will be described later.

[0175] The cleaning solution may be prepared as a kit in which the raw materials are divided into several parts.

[0176] [Preparation of cleaning solution] The cleaning solution can be produced by a known method, which will be described in detail below.

[0177] <Liquid preparation process> The method of preparing the cleaning solution is not particularly limited, and for example, the cleaning solution can be produced by mixing the above-mentioned components. The order and / or timing of mixing the above-mentioned components is not particularly limited, and for example, a method of preparing the cleaning solution includes sequentially adding a perhalogen acid, a halogen acid, and optional components to a container containing purified pure water, stirring to mix, and adding a pH adjuster to adjust the pH of the mixed solution. When adding water and each component to a container, they may be added all at once, or may be added in multiple portions.

[0178] The stirring device and the stirring method used for preparing the cleaning solution are not particularly limited, and any device known as a stirrer or disperser may be used. 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.

[0179] Mixing of each component in the preparation step of the cleaning solution, purification treatment described below, and storage of the produced cleaning solution are preferably carried out at 40° C. or less, more preferably 30° C. or less, and more preferably 5° C. or more, more preferably 10° C. or more. By preparing, treating, and / or storing the cleaning solution within the above temperature range, the performance can be stably maintained for a long period of time.

[0180] (Refining process) It is preferable to perform a purification treatment in advance for one or more of the raw materials for preparing the cleaning liquid. The purification treatment is not particularly limited, and examples thereof include known methods such as distillation, ion exchange, and filtration. The degree of purification is not particularly limited, but it is preferable to purify the raw material until the purity is 99% by mass or more, and it is more preferable to purify the raw solution until the purity is 99.9% by mass or more.

[0181] Specific examples of the purification method include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO membrane), distilling the raw material, and filtering, which will be described later. The purification process may be a combination of the above purification methods. For example, the raw material may be subjected to a primary purification process in which the raw material is passed through an RO membrane, and then a secondary purification process in which the raw material is passed through a purification device made of a cation exchange resin, an anion exchange resin, or a mixed-bed ion exchange resin. The purification process may be carried out multiple times.

[0182] (filtering) The filter used for filtering is not particularly limited as long as it is one that has been conventionally used for filtering purposes. For example, filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, and polyolefin resins (including high density or ultra-high molecular weight) such as polyethylene and polypropylene (PP) are included. Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, and fluororesin filters are more preferred. By filtering the raw material using a filter formed of these materials, highly polar foreign matter that is likely to cause defects can be effectively removed.

[0183] The critical surface tension of the filter is preferably 70 to 95 mN / m, and more preferably 75 to 85 mN / m. The critical surface tension of the filter is the nominal value of the manufacturer. By using a filter with a critical surface tension in the above range, highly polar foreign matter that is likely to cause defects can be effectively removed.

[0184] The pore size of the filter is preferably 2 to 20 nm, more preferably 2 to 15 nm. By setting it in this range, it is possible to reliably remove impurities and fine foreign matter such as aggregates contained in the raw material while suppressing filtration clogging. The pore size here can be determined based on the nominal value provided by the filter manufacturer.

[0185] Filtering may be performed only once, or may be performed two or more times. When filtering is performed two or more times, the filters used may be the same or different.

[0186] Moreover, filtering is preferably carried out at room temperature (25° C.) or below, more preferably at 23° C. or below, and even more preferably at 20° C. or below. Moreover, filtering is preferably carried out at 0° C. or above, more preferably at 5° C. or above, and even more preferably at 10° C. or above. By carrying out filtering within the above temperature range, the amount of particulate foreign matter and impurities dissolved in the raw material can be reduced, and foreign matter and impurities can be efficiently removed.

[0187] (container) The cleaning solution (including the form of a kit or a diluted solution described below) can be filled into any container and stored, transported, and used, so long as corrosiveness and other issues do not pose a problem.

[0188] The container is preferably one that is highly clean for semiconductor applications and that suppresses the elution of impurities from the inner wall of the container into each liquid. Examples of such containers include various containers that are commercially available as containers for semiconductor cleaning liquids, 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 thereto. In addition, as a container for storing a cleaning liquid, it is preferable that the liquid-contacting parts, such as the inner walls of the container, are made of a fluorine-based resin (perfluororesin) or a metal that has been treated to prevent rust and metal elution. The inner wall of the container is preferably formed from one or more resins selected from the group consisting of polyethylene resin, polypropylene resin, and polyethylene-polypropylene resin, or a different resin, or from a metal that has been treated to prevent rust and metal elution, such as stainless steel, Hastelloy, Inconel, or Monel.

[0189] The different resin is preferably a fluororesin (perfluororesin). By using a container whose inner wall is made of a fluororesin, the occurrence of the problem of elution of ethylene or propylene oligomers can be suppressed compared to a container whose inner wall is made of a polyethylene resin, a polypropylene resin, or a polyethylene-polypropylene resin. A specific example of such a container whose inner wall is a fluororesin is FluoroPure PFA composite drum manufactured by Entegris, Inc. In addition, containers described on page 4 of JP-A-3-502677, page 3 of WO 2004 / 016526, and pages 9 and 16 of WO 99 / 46309 can also be used.

[0190] In addition to the above-mentioned fluororesin, quartz and electrolytically polished metal materials (that is, metal materials that have been electrolytically polished) are also preferably used for the inner wall of the container. The metal material used in producing the electrolytically polished metal material preferably contains at least one selected from the group consisting of chromium and nickel, and the total content of chromium and nickel is more than 25 mass% based on the total mass of the metal material, and examples of such metal material include stainless steel and nickel-chromium alloys. The total content of chromium and nickel in the metal material is more preferably 30 mass % or more based on the total mass of the metal material. The upper limit of the total content of chromium and nickel in the metal material is not particularly limited, but is generally preferably 90 mass % or less.

[0191] The method for electrolytically polishing the metal material is not particularly limited, and any known method can be used. For example, the methods described in paragraphs

[0011] to

[0014] of JP 2015-227501 A and paragraphs

[0036] to

[0042] of JP 2008-264929 A can be used.

[0192] The inside of these containers is preferably washed before filling with the cleaning liquid. The liquid used for cleaning is preferably one that has a reduced amount of metal impurities. After production, the cleaning liquid may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored.

[0193] In order to prevent the components of the cleaning solution from changing during storage, the inside of the container may be replaced with an inert gas (nitrogen, argon, etc.) with a purity of 99.99995% by volume or more. In particular, a gas with a low water content is preferable. In addition, the cleaning solution may be transported and stored at room temperature, but the temperature may be controlled to a range of -20°C to 20°C to prevent deterioration.

[0194] (Clean Room) It is preferable that all of the manufacturing of the cleaning solution, the opening and cleaning of the container, the handling including filling of the cleaning solution, the processing analysis, and the measurement are carried out in a clean room. The clean room preferably meets the 14644-1 clean room standard. It is preferable that the clean room meets any of ISO (International Organization for Standardization) Class 1, ISO Class 2, ISO Class 3, and ISO Class 4, more preferably ISO Class 1 or ISO Class 2, and even more preferably ISO Class 1.

[0195] <Dilution process> The above-mentioned cleaning liquid is preferably subjected to a dilution step in which it is diluted with a diluent such as water before being used to clean a semiconductor substrate.

[0196] The dilution rate of the cleaning solution in the dilution step may be appropriately adjusted depending on the type and content of each component, and the semiconductor substrate to be cleaned, etc., but the ratio of the diluted cleaning solution to the cleaning solution before dilution is preferably 10 to 10,000 times, more preferably 20 to 3,000 times, and even more preferably 50 to 1,000 times, in volume ratio. In order to obtain a more excellent effect of the present invention, the cleaning liquid is preferably diluted with water.

[0197] The specific method of the dilution step of diluting the cleaning solution is not particularly limited, and may be carried out in accordance with the above-mentioned preparation step of the cleaning solution. The stirring device and stirring method used in the dilution step are also not particularly limited, and may be carried out using the known stirring device mentioned in the above-mentioned preparation step of the cleaning solution.

[0198] It is preferable to perform a purification treatment on the water used in the dilution step in advance, and it is also preferable to perform a purification treatment on the diluted cleaning liquid obtained in the dilution step. The purification treatment is not particularly limited, and examples thereof include the ion component reduction treatment using an ion exchange resin or an RO membrane, etc., and the removal of foreign matter using filtering, which are described above as purification treatments for the cleaning solution. It is preferable to perform any one of these treatments.

[0199] [Uses of cleaning fluid] The cleaning liquid is used in a cleaning process for cleaning semiconductor substrates that have been subjected to a chemical mechanical polishing (CMP) process, and can also be used to clean semiconductor substrates in the manufacturing process of the semiconductor substrates. In particular, when the semiconductor substrate contains a Ru-containing material and a RuO2-containing material, the present processing method is preferably used. For cleaning the semiconductor substrate, a diluted cleaning solution obtained by diluting the cleaning solution may be used.

[0200] [Items to be cleaned] An example of an object to be cleaned with the cleaning solution is a semiconductor substrate having metal inclusions. In this specification, "on a semiconductor substrate" includes, for example, the front and back surfaces, side surfaces, and inside of grooves of a semiconductor substrate. Furthermore, metal inclusions on a semiconductor substrate include not only cases where metal inclusions are directly present on the surface of a semiconductor substrate, but also cases where metal inclusions are present on a semiconductor substrate via another layer. The object to be cleaned is preferably a semiconductor substrate containing at least one selected from the group consisting of a Ru-containing material and a RuO2-containing material. The semiconductor substrate may be, for example, a laminate of a Ru-containing material and a RuO2-containing layer formed on the surface of the Ru-containing material.

[0201] Examples of the metal contained in the metal inclusion include at least one metal M selected from the group consisting of Ru (ruthenium), Cu (copper), Co (cobalt), W (tungsten), Ti (titanium), Ta (tantalum), Cr (chromium), Hf (hafnium), Os (osmium), Pt (platinum), Ni (nickel), Mn (manganese), Zr (zirconium), Mo (molybdenum), La (lanthanum), and Ir (iridium).

[0202] The metal-containing substance may be any substance containing a metal (metal atom), and examples thereof include a simple substance of metal M, an alloy containing metal M, an oxide of metal M, a nitride of metal M, and an oxynitride of metal M. The metal-containing material may also be a mixture containing two or more of these compounds. The oxides, nitrides, and oxynitrides may be composite oxides, composite nitrides, and composite oxynitrides that contain a metal. The content of metal atoms in the metal-containing material is preferably 10 mass% or more, more preferably 30 mass% or more, and even more preferably 50 mass% or more, based on the total mass of the metal-containing material. The upper limit is 100 mass% or less, since the metal-containing material may be the metal itself.

[0203] The semiconductor substrate preferably has a metal M inclusion containing the metal M, more preferably has a metal inclusion containing at least one metal selected from the group consisting of Ru, Cu, Co, W, Ti, and Ta, even more preferably has a metal inclusion containing at least one metal selected from the group consisting of Ru, Cu, Co, Ti, Ta, and W, and particularly preferably has a metal inclusion containing Ru.

[0204] The semiconductor substrate to be cleaned with the cleaning solution is not particularly limited, and examples thereof include a substrate having a metal wiring film, a barrier metal, and an insulating film on the surface of a wafer constituting a semiconductor substrate.

[0205] Specific examples of wafers constituting semiconductor substrates include silicon (Si) wafers, silicon carbide (SiC) wafers, wafers made of silicon-based materials such as resin-based wafers containing silicon (glass epoxy wafers), gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, and indium phosphide (InP) wafers. The silicon wafer may be an n-type silicon wafer doped with a pentavalent atom (e.g., phosphorus (P), arsenic (As), antimony (Sb), etc.), or a p-type silicon wafer doped with a trivalent atom (e.g., boron (B), gallium (Ga), etc.). The silicon of the silicon wafer may be, for example, any of amorphous silicon, single crystal silicon, polycrystalline silicon, and polysilicon. In particular, the cleaning liquid is useful for wafers made of silicon-based materials, such as silicon wafers, silicon carbide wafers, and resin-based wafers containing silicon (glass epoxy wafers).

[0206] The semiconductor substrate may be the above-mentioned wafer having an insulating film. Specific examples of insulating films include silicon oxide films (e.g., silicon dioxide (SiO2) film and tetraethyl orthosilicate (Si(OC2H5)4) film (TEOS film)), silicon nitride films (e.g., silicon nitride (Si3N4) and silicon carbide nitride (SiNC), etc.), and low dielectric constant (Low-k) films (e.g., carbon-doped silicon oxide (SiOC) film and silicon carbide (SiC) film, etc.).

[0207] The metal film on the semiconductor substrate may be a metal film containing at least one metal selected from the group consisting of ruthenium (Ru), copper (Cu), cobalt (Co), and tungsten (W). The semiconductor substrate preferably has a metal film containing at least one selected from the group consisting of ruthenium, copper, and cobalt, more preferably a metal film containing ruthenium, and also preferably a metal film containing tungsten.

[0208] Examples of ruthenium-containing films include wiring films made only of metallic ruthenium (ruthenium wiring films) and wiring films made of alloys made of metallic ruthenium and other metals (ruthenium alloy wiring films).

[0209] Examples of copper-containing films include wiring films made only of metallic copper (copper wiring films) and wiring films made of alloys made of metallic copper and other metals (copper alloy wiring films). Specific examples of copper alloy wiring films include wiring films made of an alloy of copper and one or more metals selected from aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), tantalum (Ta), and tungsten (W). More specifically, copper-aluminum alloy wiring film (CuAl alloy wiring film), copper-titanium alloy wiring film (CuTi alloy wiring film), copper-chromium alloy wiring film (CuCr alloy wiring film), copper-manganese alloy wiring film (CuMn alloy wiring film), copper-tantalum alloy wiring film (CuTa alloy wiring film), and copper-tungsten alloy wiring film (CuW alloy wiring film) can be mentioned.

[0210] Examples of cobalt-containing films (metal films containing cobalt as a main component) include metal films consisting only of metallic cobalt (cobalt metal films) and metal films made of alloys consisting of metallic cobalt and other metals (cobalt alloy metal films). Specific examples of the cobalt alloy metal film include metal films made of alloys of one or more metals selected from titanium (Ti), chromium (Cr), iron (Fe), nickel (Ni), molybdenum (Mo), palladium (Pd), tantalum (Ta), and tungsten (W) and cobalt. More specifically, the metal films include cobalt-titanium alloy metal film (CoTi alloy metal film), cobalt-chromium alloy metal film (CoCr alloy metal film), cobalt-iron alloy metal film (CoFe alloy metal film), cobalt-nickel alloy metal film (CoNi alloy metal film), cobalt-molybdenum alloy metal film (CoMo alloy metal film), cobalt-palladium alloy metal film (CoPd alloy metal film), cobalt-tantalum alloy metal film (CoTa alloy metal film), and cobalt-tungsten alloy metal film (CoW alloy metal film).

[0211] Examples of tungsten-containing films (metal films containing tungsten as a main component) include metal films consisting of tungsten only (tungsten metal films) and metal films made of alloys consisting of tungsten and other metals (tungsten alloy metal films). Specific examples of the tungsten alloy metal film include a tungsten-titanium alloy metal film (WTi alloy metal film) and a tungsten-cobalt alloy metal film (WCo alloy metal film). Generally, tungsten-containing films are often used as barrier metals.

[0212] There are no particular limitations on the method for forming the insulating film, copper-containing wiring film, cobalt-containing film, and tungsten-containing film on the wafer constituting the semiconductor substrate, so long as it is a method commonly used in this field. As a method for forming an insulating film, for example, a silicon oxide film is formed by performing a heat treatment on a wafer constituting a semiconductor substrate in the presence of oxygen gas, and then, gases of silane and ammonia are introduced to form a silicon nitride film by a chemical vapor deposition (CVD) method. As a method for forming a ruthenium-containing wiring film, a copper-containing wiring film, a cobalt-containing film, and a tungsten-containing film, for example, a circuit is formed on a wafer having the above insulating film by a known method such as a resist, and then, a ruthenium-containing wiring film, a copper-containing wiring film, a cobalt-containing film, and a tungsten-containing film are formed by methods such as plating and CVD method.

[0213] <CMP process> The CMP process is a process of planarizing the surface of a substrate having a metal wiring film, a barrier metal, and an insulating film by a combined action of a chemical action using a polishing slurry containing polishing fine particles (abrasive grains) and mechanical polishing. On the surface of a semiconductor substrate subjected to the CMP process, impurities such as abrasive grains (for example, silica and alumina etc.) used in the CMP process, polished metal wiring film, and metal impurities (metal residues) derived from the barrier metal may remain. Since these impurities may, for example, cause a short circuit between wirings and deteriorate the electrical characteristics of the semiconductor substrate, the semiconductor substrate subjected to the CMP process is subjected to a cleaning process for removing these impurities from the surface. As a specific example of a semiconductor substrate subjected to the CMP process, a substrate subjected to the CMP process described in Journal of the Precision Engineering Society Vol.84, No.3, 2018 can be mentioned, but it is not limited thereto.

[0214] 〔Cleaning method of semiconductor substrate〕 The cleaning method of the semiconductor substrate is not particularly limited as long as it includes a cleaning step of cleaning the semiconductor substrate subjected to the CMP process using the above cleaning liquid. It is preferable that the cleaning method of the semiconductor substrate includes a step of applying the diluted cleaning liquid obtained in the above dilution step to the semiconductor substrate subjected to the CMP process and cleaning it.

[0215] The cleaning step of cleaning the semiconductor substrate with a cleaning solution is not particularly limited as long as it is a known method performed on a semiconductor substrate that has been subjected to CMP, and any method that is usually used in this field may be appropriately adopted, such as brush scrub cleaning in which a cleaning member such as a brush is brought into physical contact with the surface of the semiconductor substrate while a cleaning solution is supplied to the semiconductor substrate to remove residues, an immersion type in which the semiconductor substrate is immersed in the cleaning solution, a spin (drop) type in which the cleaning solution is dropped while the semiconductor substrate is rotated, and a spray (spray) type in which the cleaning solution is sprayed. In the immersion type cleaning, it is preferable to subject the cleaning solution in which the semiconductor substrate is immersed to ultrasonic treatment, since this can further reduce impurities remaining on the surface of the semiconductor substrate. The above washing step may be carried out only once, or may be carried out two or more times. When washing is carried out two or more times, the same method may be repeated, or different methods may be combined.

[0216] The method for cleaning the semiconductor substrate may be either a single-wafer method or a batch method. The single-wafer method is generally a method for processing semiconductor substrates one by one, while the batch method is generally a method for processing multiple semiconductor substrates simultaneously.

[0217] The temperature of the cleaning solution used for cleaning the semiconductor substrate is not particularly limited as long as it is a temperature that is usually used in this field. Generally, cleaning is performed at room temperature (25°C), but the temperature can be selected arbitrarily to improve cleaning properties and suppress damage to components. The temperature of the cleaning solution is preferably 10 to 60°C, more preferably 15 to 50°C.

[0218] The cleaning time for cleaning a semiconductor substrate cannot be generally determined because it depends on the types and contents of components contained in the cleaning solution, but in practice, it is preferably 10 seconds to 2 minutes, more preferably 20 seconds to 1 minute and 30 seconds, and even more preferably 30 seconds to 1 minute.

[0219] The supply amount (supply rate) of the cleaning liquid in the step of cleaning the semiconductor substrate is not particularly limited, but is preferably 50 to 5000 mL / min, and more preferably 500 to 2000 mL / min.

[0220] In cleaning semiconductor substrates, mechanical agitation may be used to further enhance the cleaning ability of the cleaning solution. Examples of the mechanical agitation method include a method of circulating the cleaning liquid above the semiconductor substrate, a method of passing or spraying the cleaning liquid above the semiconductor substrate, and a method of agitating the cleaning liquid by ultrasonic waves or megasonics.

[0221] After the above-mentioned cleaning of the semiconductor substrate, a step of rinsing and cleaning the semiconductor substrate with a solvent (hereinafter referred to as a "rinsing step") may be carried out. The rinsing step is preferably performed consecutively after the cleaning step of the semiconductor substrate, and is a step of rinsing with a rinsing liquid for 5 seconds to 5 minutes. The rinsing step may be performed using the mechanical stirring method described above.

[0222] Rinsing solutions include, for example, water (preferably deionized (DI) water), methanol, ethanol, isopropyl alcohol, N-methylpyrrolidinone, γ-butyrolactone, dimethylsulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Aqueous rinsing solutions having a pH greater than 8 (such as dilute aqueous ammonium hydroxide) may also be utilized. As a method for bringing the rinsing liquid into contact with the semiconductor substrate, the above-mentioned method for bringing the cleaning liquid into contact with the semiconductor substrate can be similarly applied.

[0223] After the rinsing step, a drying step of drying the semiconductor substrate may be performed. The drying method is not particularly limited, and examples thereof include a spin drying method, a method of passing a dry gas over a semiconductor substrate, a method of heating the substrate with a heating means such as a hot plate or an infrared lamp, a Marangoni drying method, a Rotagoni drying method, an IPA (isopropyl alcohol) drying method, and any combination thereof. EXAMPLES

[0224] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, and ratios 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 interpreted as being limited by the following examples.

[0225] In the following examples, the pH of the cleaning solution was measured at 25° C. using a pH meter (manufactured by Horiba Ltd., model "F-74") in accordance with JIS Z8802-1984. In addition, in producing the cleaning solutions of the Examples and Comparative Examples, handling of containers, preparation, filling, storage, and analysis of the cleaning solutions were all carried out in a clean room that met ISO class 2 or lower.

[0226] [Cleaning solution ingredients] The following compounds were used to prepare the cleaning solution. Note that all of the components used in the examples were classified as semiconductor grade or equivalent high purity grade.

[0227] [Perhalogen acid] Orthoperiodic acid: Fujifilm Wako Pure Chemical Industries, Ltd. [Halogen acids] Iodic acid: Fujifilm Wako Pure Chemical Industries, Ltd. [Organic acid] Diethylenetriaminepentaacetic acid (DTPA): Fujifilm Wako Pure Chemical Industries, Ltd. Ethylenediaminetetraacetic acid (EDTA): manufactured by Chelesto 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP): Thermophos "Dequest 2000" Citric acid (CA): manufactured by Fuso Chemical Co., Ltd. [Corrosion inhibitor] <Phosphate ester acid surfactant> (CH3)2Ph-(OE)6OPO3H2: Takemoto Oil Co., Ltd., product name "Phosphanol FS-3PG" <Heterocyclic compounds> Azole compound 1: 2,2'-{[(5-methyl-1H-benzotriazol-1-yl)methyl]imino}diethanol 3-amino-5-methyl-pyrazole: manufactured by Tokyo Chemical Industry Co., Ltd. 1,2,4-triazole: Fujifilm Wako Pure Chemical Industries, Ltd. [Organic base compounds] <Primary amine> 2-Amino-2-methyl-1-propanol (AMP): Fujifilm Wako Pure Chemical Industries, Ltd. <Secondary amine> Tetraethylammonium hydroxide (TEAH): Fujifilm Wako Pure Chemical Industries, Ltd. Tetrabutylammonium hydroxide (TBAH): Fujifilm Wako Pure Chemical Industries, Ltd. Tetrapropylammonium hydroxide (TPAH): Fujifilm Wako Pure Chemical Industries, Ltd. Tetrabutylphosphonium hydroxide (TBPH): Fujifilm Wako Pure Chemical Industries, Ltd. Diazabicycloundecene (DBU): Fujifilm Wako Pure Chemical Industries, Ltd. [pH adjuster] Sulfuric acid (H2SO4): Fujifilm Wako Pure Chemical Industries, Ltd. [Additives] <Polymer> Polyacrylic acid (Mw=700,000): manufactured by Toagosei Co., Ltd., product name "Jurimer AC-10H" Polyacrylic acid (Mw=55,000): manufactured by Toagosei Co., Ltd., product name "Jurimer AC-10L" Polyacrylic acid (Mw=6,000): Aron A-10SL, manufactured by Toagosei Co., Ltd. Polyacrylic acid (Mw = 1000 or more but less than 2000): manufactured by Aldrich, trade name "Poly(acrylic acid)" Polymaleic acid (Mw=2,000): NOF Corporation, product name "Non-Pol PWA-50W"

[0228] [Cleaning solution manufacturing] Next, a method for producing a cleaning liquid will be described using Example 1 as an example. Orthoperiodic acid, iodic acid, tetraethylammonium hydroxide (TEAH), and diazabicycloundecene (DBU) were added to ultrapure water in amounts corresponding to the contents shown in Tables 1 and 2, and then sulfuric acid was added so that the pH of the cleaning solution to be prepared was 11. The resulting mixture was thoroughly stirred with a stirrer to obtain the cleaning solution of Example 1.

[0229] According to the manufacturing method of Example 1, cleaning solutions of Examples 2 to 51 and Comparative Example 1 having the compositions shown in Tables 1 and 2 were manufactured, respectively.

[0230] In the table, the column "mass (%)" indicates the content (unit: mass %) of each component relative to the total mass of the cleaning solution. The numerical values ​​in the "Ratio" ((A) / (B)) column represent the mass ratio of the perhalogen acid content to the halogen acid content [perhalogen acid content / halogen acid content]. The "*1" in the "pH adjuster" column means that, if necessary, H2SO4 was added in an amount that would adjust the pH of the prepared cleaning solution to the value in the "pH" column. The "balance" in the "Water" column means that the remainder of the cleaning solution other than the components listed in Tables 1 and 2 is water. The values ​​in the "pH" column indicate the pH of the cleaning solution at 25°C as measured using the pH meter described above. The value in the "pH after dilution" column indicates the pH at 25°C of the cleaning solution diluted 100 times by volume with ultrapure water, as measured using the pH meter described above.

[0231] [Evaluation of removal performance] The cleaning solution produced by the above method was used to evaluate its ability to remove metal films containing ruthenium or ruthenium oxide. 2 mL of the cleaning solution from each of the Examples and Comparative Examples was dispensed and diluted 100 times in volume with ultrapure water to prepare a diluted cleaning solution (200 mL). A wafer (diameter 12 inches) of a metal film having ruthenium or ruthenium oxide on its surface was cut to prepare wafer coupons of 10 nm thickness and 2 cm length x 2 cm width. The wafer coupon was immersed in the diluted cleaning solution and stirred for 30 minutes at room temperature with a stirring speed of 250 rpm. After stirring, each metal film was observed by the following method, and the average thickness of the removed film was calculated, and the removal rate per unit time was calculated. Then, the ratio of the removal rate of RuO2 to the removal rate of Ru (RuO2 / Ru) was calculated from the removal rate of each metal film. The surface was observed using a Review SEM observation device manufactured by Applied Materials Technology, Inc., and the thickness was measured at 100 random locations. The cleaning solution was evaluated for its removal performance according to the following criteria: The faster the RuO2 removal rate, the better, and the higher the RuO2 / Ru ratio, the better. (RuO2 evaluation criteria (RuO2 removal rate)) A: Removal speed is 2A / min or more B: Removal speed is 1A / min or more and less than 2A / min C: Removal rate is less than 1A / min (RuO2 / Ru evaluation criteria (RuO2 / Ru selectivity)) A: RuO2 / Ru is 5 or more B: RuO2 / Ru is 3 or more and less than 5 C: RuO2 / Ru is 1 or more and less than 3 D: RuO2 / Ru is less than 1

[0232] [Table 1]

[0233] [Table 2]

[0234] [Table 3]

[0235] [result] As is clear from Tables 1 and 2, it was confirmed that the cleaning solution of the present invention has excellent selectivity in the removal performance of RuO2.

[0236] Comparison with Examples 22 to 29 and 31 confirmed that a more excellent effect was achieved when the pH value of the cleaning solution used was 2.0 to 12.0. Comparison with Examples 1 to 8 and 17 to 20 confirmed that when the mass ratio of the content of perhalogen acid to the content of halogen acid was 0.00001 to 50, a more excellent effect was achieved. Comparing Example 29 with Example 30, it was confirmed that the effect was even better when an organic base compound was further contained. A comparison of Examples 47 to 51 confirmed that when Polymer B was contained, the effect was more excellent.

Claims

1. A cleaning solution for a semiconductor substrate that has been subjected to a chemical mechanical polishing process, comprising: Contains a perhalogen acid and a halogen acid, a mass ratio of the content of the perhalogen acid to the content of the halogen acid is 0.00001 to 0.9; Further comprising an organic base compound, The cleaning solution, wherein the organic base compound comprises at least one selected from the group consisting of a first amine compound represented by formula (1), a quaternary ammonium compound, and a quaternary phosphonium compound. 【Chemistry 1】 In formula (1), R １ , R ２ , and R ３ Each of R represents an organic group. １ , R ２ , and R ３ A plurality of these may be bonded to each other to form a non-aromatic ring which may have a substituent.

2. 2. The cleaning solution according to claim 1, wherein the quaternary ammonium compound is a quaternary ammonium hydroxide represented by formula (2): (R ４ ) ４ N ＋ OH － (2) In the formula, R ４ represents an alkyl group which may have a hydroxyl group or a phenyl group as a substituent. ４ may be the same or different from each other.

3. R ４ The cleaning solution according to claim 2, wherein is a methyl group, an ethyl group, a propyl group, a butyl group, a 2-hydroxyethyl group, or a benzyl group.

4. The cleaning solution according to any one of claims 1 to 3, wherein the content of the organic base compound is 0.05 mass % or more and 25 mass % or less with respect to the total mass of the cleaning solution.

5. The cleaning solution according to any one of claims 1 to 4, wherein the content of the organic base compound is 1 mass % or more and 50 mass % or less with respect to the total mass of the components in the cleaning solution excluding the solvent.

6. The cleaning solution according to any one of claims 1 to 5, wherein the pH value of the cleaning solution is from 2.0 to 12.

0.

7. 7. The cleaning solution according to claim 1, wherein a mass ratio of the content of the perhalogen acid to the content of the halogen acid is 0.00001 to 0.

25.

8. The cleaning solution according to any one of claims 1 to 7, further comprising an organic acid.

9. The cleaning solution according to claim 8 , wherein the organic acid has at least one selected from the group consisting of a carboxyl group and a phosphonic acid group.

10. The cleaning solution according to any one of claims 1 to 9, further comprising at least one selected from the group consisting of an anticorrosive, a surfactant, a polymer A having a weight average molecular weight of 500 or more and less than 2000, and a polymer B having a weight average molecular weight of 2000 or more.

11. Further comprising a corrosion inhibitor; The cleaning solution according to any one of claims 1 to 10, wherein the anticorrosive agent is a heterocyclic compound.

12. The cleaning solution according to claim 11, wherein the anticorrosive agent comprises at least one selected from the group consisting of a tetrazole compound, a triazole compound, an imidazole compound, a pyrazole compound, and derivatives thereof.

13. Further comprising a surfactant, The cleaning solution according to any one of claims 1 to 12, wherein the surfactant is an anionic or nonionic surfactant.

14. Further comprising a polymer B having a molecular weight of 2000 or more, The cleaning solution according to any one of claims 1 to 13, wherein the polymer B has a carboxyl group or an acid anhydride group.

15. A method for cleaning a semiconductor substrate, comprising the step of cleaning a semiconductor substrate that has been subjected to chemical mechanical polishing treatment, with the cleaning solution according to any one of claims 1 to 14.

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