Cleaning solution, method for cleaning semiconductor substrates

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 liquid and a method for cleaning a semiconductor substrate.

Background Art

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

[0003] For example, Patent Document 1 discloses a treatment liquid for etching treatment for Ru metal.

Prior Art Documents

Patent Documents

[0009] [1] A cleaning solution for semiconductor substrates that have undergone chemical mechanical polishing, A cleaning solution containing perhalic acid and halogen acid. [2] The cleaning solution described in [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 the mass ratio of the perhalic acid content to the halogenic acid content is 0.00001 to 50. [4] A washing solution according to any one of [1] to [3], further comprising an organic base compound. [5] The washing 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 formula (1) described later, a quaternary ammonium compound, and a quaternary phosphonium compound. [6] A cleaning solution according to any one of [1] to [5], further containing an organic acid. [7] The washing solution according to [6], wherein the organic acid is selected from the group consisting of carboxyl groups and phosphonic acid groups. [8] A cleaning solution according to any one of [1] to [7], further comprising at least one selected from the group consisting of a corrosion inhibitor, a surfactant, 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. [9] It also contains a corrosion inhibitor. A washing solution according to any one of [1] to [8], wherein the corrosion inhibitor is a heterocyclic compound.

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

[11] It further contains surfactants, A cleaning solution according to any one of [1] to

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

[12] It further contains polymer B with a molecular weight of 2000 or more, The cleaning solution according to any one of [1] to

[11] , wherein 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 undergone chemical mechanical polishing treatment using a cleaning solution described in any one of [1] to

[12] . [Effects of the Invention]

[0010] According to the present invention, for a semiconductor substrate subjected to CMP New Cleaning liquid We can provide it. Furthermore, the present invention provides a method for cleaning semiconductor substrates that have undergone CMP (Cleaning and Modification). [Modes for carrying out the invention]

[0011] An example of an embodiment for carrying out the present invention is described below. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively.

[0012] In this specification, if two or more components are present, the "content" of those components means the total content of those two or more components. In this specification, "ppm" means "parts-per-million (10 -6 ) means "ppb" is "parts-per-billion (10 -9 It means ")". Unless otherwise specified, the compounds described herein may include isomers (compounds with the same number of atoms but different structures), optical isomers, and isotopes. Furthermore, only one isomer or multiple isotopes may be included.

[0013] In this specification, psi means pound-force per square inch; 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 undergone chemical mechanical polishing (CMP), and is a cleaning solution containing a perhalic acid and a halogen acid.

[0015] The inventors of the present invention have discovered that by including a perhalic acid and a halogen acid in the cleaning solution, 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 the cleaning process of a semiconductor substrate containing Ru that has been subjected to CMP, and have completed the present invention.

[0016] Although the detailed mechanism by which such a cleaning solution achieves the effects of the present invention is unknown, it is hypothesized that the inclusion of perhalic acid and halogen acid allows the perhalic acid to improve the RuO2 removal performance, while the halogen acid suppresses the Ru removal performance, resulting in high selectivity for RuO2.

[0017] [Cleaning solution] The cleaning solution contains perhalic acid and halogen acid. The following describes each component contained in the cleaning solution.

[0018] [Perhalic acid] The cleaning solution of the present invention contains a perhalic acid. Perhalic acid refers to a peroxide that contains halogen atoms. Examples of perhalic acids include periodic acid, perchloric acid, perbromic acid, and salts thereof. Among these, periodic acid or perchloric acid is preferred as the perhalic acid, with periodic acid being more preferred, as it provides superior effects for the present invention.

[0019] While there are no particular limitations on the periodic acid used, at least one selected from the group consisting of orthoperiodic acid (H5IO6), metaperiodic acid (HIO4), and their salts is preferred in terms of superior effects of the present invention, with orthoperiodic acid or metaperiodic acid being more preferred. Orthoperiodic acid is even more preferred because it does not contain alkali metals such as sodium (Na) and has a stable composition.

[0020] Examples of perhalic acid salts include alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium, calcium, and barium; and ammonium salts.

[0021] Perhalic acids may be used individually or in combination of two or more types. The perhalic acid content is preferably 0.00001 to 5% by mass, more preferably 0.0001 to 3% by mass, and even more preferably 0.0001 to 2.5% by mass, relative to the total mass of the cleaning solution, in order to achieve superior effects of the present invention. Furthermore, the perhalic acid content is preferably 0.0001 to 80% by mass, more preferably 0.001 to 75% by mass, and even more preferably 0.001 to 70% by mass, based on the total mass of the components excluding the solvent in the cleaning solution, in order to achieve superior effects of the present invention. The total mass of the components in the cleaning solution excluding the solvent refers to the total mass of components other than the solvent, such as water (e.g., perhalic acid and halogen acid).

[0022] [Halogenated acids] The cleaning solution of the present invention contains a halogenated acid. Halogenated acids refer to oxides containing halogen atoms with one less oxygen atom than perhalogenated acids, as described above. In other words, halogenated acids do not include perhalogenated acids or hypohalous acids.

[0023] Examples of halogen acids include iodic acid, chloric acid, bromic acid, and salts thereof. Among these, iodic acid or chloric acid is preferred as the halogen acid, with iodic acid being more preferred, as it provides superior effects for the present invention.

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

[0025] Halogenated acids may be used individually or in combination of two or more types. The halogen acid content is preferably 0.0005 to 4.5% by mass, more preferably 0.05 to 4.5% by mass, and even more preferably 3 to 4.5% by mass, relative to the total mass of the cleaning solution, in order to achieve superior effects of the present invention. Furthermore, the halogen acid content is preferably 0.01 to 99.99% by mass, more preferably 1.0 to 85% by mass, and even more preferably 40 to 85% by mass, based on the total mass of the components excluding the solvent in the cleaning solution, in order to achieve superior effects of the present invention.

[0026] The mass ratio of the perhalic acid content to the halogenic acid content [perhalic acid content / halogenic acid content] is preferably 0.00001 to 5000, more preferably 0.00001 to 50, even 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 washing solution is preferably between 1 and 14 at 25°C. In particular, a pH value of 2.0 to 12.0 is preferred, and 4.0 to 12.0 is more preferred, in terms of achieving superior effects according to the present invention. The pH value of the cleaning solution can be adjusted by using pH adjusters, organic base compounds, organic acids, corrosion inhibitors, and surfactants, which are components that have the function of pH adjusters, as described later. The pH value of the cleaning solution can be measured using a known pH meter in accordance with the method specified in JIS Z8802-1984. As described later, when the cleaning solution is used after dilution, it is preferable that the pH at the time of dilution is within the above range.

[0028] [Optional ingredients] The cleaning solution may contain other optional components in addition to those described above. Examples of optional components include organic base compounds, organic acids, corrosion inhibitors, surfactants, pH adjusters, various additives, and water. The cleaning solution preferably contains at least one selected from the group consisting of organic base compounds, organic acids, surfactants (more preferably anionic surfactants), pH adjusters, and polymers. The optional components may be used individually or in combination of two or more.

[0029] The optional components are explained below.

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

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

[0032] [ka]

[0033] In formula (1), R 1 , R 2 , and R 3All represent organic groups. R 1 、R 2 、and R 3 Among them, a plurality may combine with each other to form a non-aromatic ring which may have a substituent.

[0034] R 1 、R 2 、and R 3 Examples of the organic groups represented by R R 1 、R 2 、and R 3 include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, and an aryl group. These groups may have a substituent. Examples of the substituent include a hydroxyl group and an amino group. Further, the alkyl group, the alkenyl group, and the alkynyl group may each be either linear or branched.

[0035] R 1 、R 2 、and R 3 Examples of the non-aromatic ring which may have a substituent and which is formed by a plurality of them combining with each other are not particularly limited, and include, for example, a cycloalkane ring having 5 to 10 carbon atoms, and a cyclopentane ring, a cyclohexane ring, or a cycloheptane ring is preferred. Examples of the substituent which the above non-aromatic ring may have include, for example, an alkyl group having 1 to 4 carbon atoms.

[0036] R 1 、R 2 、and R 3 As the organic groups represented by R Among them, R 1 、R 2 、and R 3A combination in which 0 to 2 alkyl groups have hydroxyl groups and the remaining 1 to 3 alkyl groups do not have hydroxyl groups is more preferable.

[0037] The primary amine is preferably a primary amino alcohol because it provides superior long-term stability of the washing solution. That is, in formula (1) above, R 1 , R 2 , and R 3 It is preferable that at least one of the organic groups represented by has a hydroxyl group. As for primary amino alcohols, R 1 , R 2 , and R 3 Preferably, one or two of the organic groups represented by have a hydroxyl group, R 1 , R 2 , and R 3 It is more preferable that only one of the organic groups represented by has a hydroxyl group.

[0038] The primary acid dissociation constant (hereinafter also referred to as "pKa1") of the conjugate acid of the primary amine is preferably 8.5 or higher. A pKa1 of 8.5 or higher for the primary amine leads to a more stable pH of the cleaning solution, improving the cleaning performance and corrosion prevention performance of the cleaning solution. The pKa1 of the primary amine is preferably 8.8 or higher, and more preferably 9.0 or higher, in terms of superior cleaning and corrosion prevention performance. There is no particular upper limit, but 12.0 or lower is preferred.

[0039] Examples of primary amino alcohols include 2-amino-2-methyl-1-propanol (AMP) (pKa1:9.72), 2-amino-2-methyl-1,3-dipropanol (AMPD) (pKa1:8.80), and 2-amino-2-ethyl-1,3-dipropanol (AEPD) (pKa1:8.80). The first amine is preferably AMP, AMPD, or AEPD, with AMP being more preferred.

[0040] The first amine may be used alone or in combination of two or more types. 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, relative to the total mass of the cleaning solution. There is no particular upper limit, 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, relative to the total mass of the cleaning solution. Furthermore, the content of the first 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 excluding the solvent in the cleaning solution, in order to further enhance the effects of the present invention. There is no particular upper limit, but in order to further enhance the effects of the present invention, it 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 excluding the solvent in the cleaning solution.

[0041] (Second amine compound) The cleaning solution may contain a second amine compound (hereinafter also referred to as the "second amine") that is different from the first 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 or salt thereof having a quaternary ammonium cation in which four hydrocarbon groups (preferably alkyl groups) are substituted on the nitrogen atom. Examples of quaternary ammonium compounds include quaternary ammonium hydroxide, quaternary ammonium fluoride, quaternary ammonium bromide, quaternary ammonium iodide, quaternary ammonium acetate, and quaternary ammonium carbonate. Among these, quaternary ammonium hydroxide is preferred.

[0043] As a quaternary ammonium compound, a quaternary ammonium hydroxide represented by the following formula (2) is preferred.

[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 R 4 They may be the same or different from one another.

[0046] R 4 The alkyl group represented is preferably an alkyl group having 1 to 6 carbon atoms, and a propyl group or a butyl group is preferred. R 4 The alkyl group which may have a hydroxyl group or a phenyl group represented by 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 an example of a quaternary ammonium compound other than the specific examples above, for instance, the compound described in paragraph

[0021] of Japanese Patent Publication No. 2018-107353 can be referenced, and this content is incorporated herein by reference.

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

[0049] - Primary to Tertiary Aliphatic Amines - Primary to tertiary aliphatic amines are not particularly limited as long as they are compounds or salts thereof that have 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") in their molecule, 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, with hydrochloride salts, sulfate salts, or nitrate salts being preferred.

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

[0051] =amino alcohol= Amino alcohols are compounds from primary to tertiary aliphatic amines that further have at least one hydroxylalkyl group in their molecule. Amino alcohols may have any of the primary to tertiary amino groups, but it is preferable that they have a primary amino group.

[0052] Examples of amino alcohols included in 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 are preferred, with N-MAMP, MEA, or AEE being more preferred. Furthermore, in terms of superior cleaning performance, MEA, DEA, AEE, or AAE are 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 alicyclic amine compounds include cyclic amidine compounds and piperazine compounds.

[0054] Cyclic amidine compounds are compounds that have a heterocycle containing an amidine structure (>NC=N-) within 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]undeca-7-ene: DBU), diazabicyclononene (1,5-diazabicyclo[4.3.0]nona-5-ene: DBN), 3,4,6,7,8,9,10,11-octahydro-2H-pyrimido[1.2-a]azosine, 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] Piperazine compounds are compounds that have a heterosix-membered ring (piperazine ring) in which the opposing -CH- group of a cyclohexane ring is replaced by a nitrogen atom. The piperazine compound may have substituents on the piperazine ring. Examples of such substituents include a hydroxyl group, a C1-C4 alkyl group which may have a hydroxyl group, and a C6-C10 aryl group.

[0056] Examples of piperazine compounds 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. Examples include (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] Examples of alicyclic amine compounds include, in addition to those mentioned above, compounds having a non-aromatic hetero-five-membered ring such as 1,3-dimethyl-2-imidazolidinone and imidazolidinthion, as well as compounds having a seven-membered ring containing a nitrogen atom.

[0058] =Aliphatic monoamine compounds= Aliphatic monoamine compounds other than amino alcohols and alicyclic amines are not particularly limited as long as they are not included in the primary amines, but examples 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 compounds= 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 polyalkyl polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), bis(aminopropyl)ethylenediamine (BAPEDA), and tetraethylenepentamine.

[0060] Furthermore, as primary to tertiary aliphatic amines, compounds not included in the primary amines among those listed in paragraphs

[0034] to

[0056] of International Publication No. 2013 / 162020 can be used, and this is incorporated herein by reference.

[0061] As primary to tertiary aliphatic amines, it is preferable that they have one or more hydrophilic groups in addition to one amino group from among primary to tertiary. Examples of hydrophilic groups include primary to tertiary amino groups and hydroxyl groups. Examples of primary to tertiary aliphatic amines having one or more hydrophilic groups in addition to one amino group from among primary to tertiary include compounds having two or more hydrophilic groups from among amino alcohols, aliphatic polyamine compounds, and alicyclic amine compounds, with amino alcohols or cyclic amidine compounds being preferred. There is no particular upper limit to the total number of hydrophilic groups that a primary to tertiary aliphatic amine may have, but it is preferably 4 or less, and more preferably 3 or less.

[0062] The number of primary to tertiary amino groups in a primary to tertiary aliphatic amine is not particularly limited, but 1 to 4 is preferred, and 1 to 3 is more preferred. Furthermore, 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. The lower limit is not particularly limited, but 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 higher, more preferably 8.6 or higher, and even more preferably 8.7 or higher, in terms of superior long-term stability of the washing solution. There is no particular upper limit, but it is preferably 20.0 or lower.

[0064] The secondary amine is preferably a primary to tertiary aliphatic amine corresponding to a quaternary ammonium compound, an amino alcohol, or a cyclic amidine compound, more preferably 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, even more preferably TEAH, TPAH, TBAH, N-MAMP, MEA, AEE, MTEAH, or DBU, and particularly preferably TEAH, TPAH, TBAH, or DBU.

[0065] The secondary amine may be used alone or in combination of two or more. The washing solution preferably contains two or more secondary amines. When the washing solution contains two or more secondary amines, it is preferable that it 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 combinations of the compounds described as 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. Furthermore, the upper limit of the secondary amine content 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 of the metal film. Furthermore, 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 excluding the solvent in the cleaning solution, in order to further enhance the effects of the present invention. There is no particular upper limit, but in order to further enhance the effects of the present invention, it 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 excluding the solvent in the cleaning solution.

[0067] (Quaternary phosphonium salt) Examples of quaternary phosphonium salts include tetraalkylphosphonium salts, trialkylarylphosphonium salts, dialkyldiarylphosphonium salts, alkyltriarylphosphonium salts, and tetraarylphosphonium salts.

[0068] Anions found in quaternary phosphonium salts include, for example, halogen ions (e.g., F - Cl - , Br - , and I - Examples include hydroxide ions, nitrate ions, nitrite ions, hypochlorite ions, chlorite ions, chlorate ions, perchlorate ions, acetate ions, bicarbonate ions, phosphate ions, sulfate ions, bisulfate ions, sulfite ions, thiosulfate ions, and carbonate ions.

[0069] Examples of quaternary phosphonium salts 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, and 4- Examples include toxybenzyltriphenylphosphonium 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] Quaternary phosphonium salts may be used individually or in combination of two or more types. The content of quaternary phosphonium salts in the cleaning solution is not particularly limited, but is preferably 0.05% by mass or more, more preferably 0.1% by mass, and even more preferably 1% by mass or more, relative to the total mass of the cleaning solution. There is no particular upper limit, 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, relative to the total mass of the cleaning solution. Furthermore, 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 excluding the solvent in the cleaning solution, in order to further enhance the effects of the present invention. There is no particular upper limit, but in order to further enhance the effects of the present invention, it 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 excluding the solvent in the cleaning solution.

[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, with AMP, TEAH, TPAH, TBAH, or DBU being more preferred.

[0072] The specific organic base compound may be used individually or in combination of two or more types. 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 achieving superior 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. Furthermore, 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 excluding the solvent in the cleaning solution, in order to further enhance the effects of the present invention. There is no particular upper limit, but in order to further enhance the effects of the present invention, it 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 excluding the solvent in the cleaning solution.

[0073] <Organic acid> Organic acids are organic compounds that have acidic functional groups and exhibit acidity (pH less than 7.0) in aqueous solution. Examples of acidic functional groups include carboxyl groups, phosphonic acid groups, sulfo groups, phenolic hydroxyl groups, and mercapto groups, with carboxylic acids or phosphonic acids being preferred. In this specification, compounds that function as anionic surfactants, as described later, are not included in organic acids.

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

[0075] The number of acidic functional groups in an organic acid is not particularly limited, but 1 to 10 is preferred, 2 to 9 is more preferred, and 3 to 8 is even more preferred. Furthermore, organic acids are preferably compounds that have the function of chelating with metals contained in the residue, as they offer superior cleaning performance, and are more preferably compounds that have two or more functional groups (coordinating groups) that coordinate with metal ions within the molecule. Examples of coordinating groups include the acidic functional groups mentioned above, with carboxylic acid groups or phosphonic acid groups being 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 is preferably having two or more carboxyl groups, more preferably 2 to 7, and even more preferably 3 to 6.

[0077] Examples of carboxylic acids include aminopolycarboxylic acids, hydroxycarboxylic acids, amino acids, and aliphatic carboxylic acids.

[0078] -amino polycarboxylic acid- Aminopolycarboxylic acids are compounds that have one or more amino groups and two or more carboxyl groups as coordination groups within their 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). Among these, DTPA, EDTA, CyDTA, or IDA are preferred, with DTPA or EDTA being more preferred.

[0079] -hydroxycarboxylic acid- Hydroxycarboxylic acids are compounds that have one or more hydroxyl groups and one or more carboxyl groups in their molecule. The cleaning solution preferably contains a hydroxycarboxylic acid, as this enhances the effects of the present invention. 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- Amino acids are compounds that have one carboxyl group and one or more amino groups in their 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 Japanese Patent Publication No. 2016-086094, and salts thereof. As histidine derivatives, compounds described in Japanese Patent Publication No. 2015-165561 and Japanese Patent Publication No. 2015-165562, etc., can be used, and their contents are incorporated herein. Examples of salts include alkali metal salts such as sodium salts and potassium salts, ammonium salts, carbonates, and acetate salts. Among these, sulfur-containing amino acids containing 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 of the cleaning solution (cleaning performance and corrosion prevention) compared to other chelating agents. The detailed mechanism for this unique effect of adipic acid is unknown, but it is thought to be due to the excellent hydrophilicity and hydrophobicity of the number of carbon chains of the alkylene group in relation to the two carboxyl groups, which allows for the formation of a stable ring structure when complexing with metals.

[0082] Examples of carboxylic acids other than the aminopolycarboxylic acids, hydroxycarboxylic acids, amino acids, and aliphatic carboxylic acids mentioned above include monocarboxylic acids. Examples of monocarboxylic acids include lower (1-4 carbon atoms) aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, and butyric acid.

[0083] As the carboxylic acid, aminopolycarboxylic acid or hydroxycarboxylic acid is preferred, and DTPA, EDTA, or citric acid is more preferred.

[0084] Carboxylic acids may be used individually or in combination of two or more types. The carboxylic acid content in the cleaning solution is not particularly limited, but is preferably 10% by mass or less, and more preferably 5% by mass or less, relative to the total mass of the cleaning solution. The lower limit is not particularly limited, but is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the cleaning solution. Furthermore, the carboxylic acid content is preferably 40% by mass or less, and more preferably 10% by mass or less, relative to the total mass of the components excluding the solvent in the washing solution, in order to achieve superior effects of the present invention. There is no particular lower limit, but it is preferably 0.001% by mass or more, and more preferably 0.01% by mass or more, relative to the total mass of the components excluding the solvent in the washing solution.

[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. Polyphosphonic acid having two or more phosphonic acid groups is preferred because it offers superior cleaning performance.

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

[0087] [ka]

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

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

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

[0091] [ka]

[0092] In the formula, Q is a hydrogen atom or R 13 - Represents PO3H2, R 12 and R 13 Each of these independently represents an alkylene group, where Y is a hydrogen atom and -R is a hydrogen atom. 13 - Represents a group represented by the formula (P4) below, or PO3H2.

[0093] [ka]

[0094] In the formula, Q and R 13 Q and R in equation (P2) are 13 It is the same as this.

[0095] In equation (P2), R 12 Examples of alkylene groups represented by this formula include linear or branched alkylene groups having 1 to 12 carbon atoms. R 12The alkylene group represented 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 even more preferably an ethylene group. In equations (P2) and (P4), R 13 Examples of alkylene groups represented by include linear or branched alkylene groups having 1 to 10 carbon atoms, with linear or branched alkylene groups having 1 to 4 carbon atoms being preferred, a methylene group or an ethylene group being more preferred, and a methylene group being even more preferred. In equations (P2) and (P4), Q is -R 13 -PO3H2 is preferred. In equation (P2), Y is -R 13 A group represented by -PO3H2 or formula (P4) is preferred, and a group represented by formula (P4) is more preferred.

[0096] Preferred compounds represented by formula (P2) include ethylaminobis(methylenephosphonic acid), dodecylaminobis(methylenephosphonic acid), nitrilotris(methylenephosphonic acid) (NTPO), ethylenediaminebis(methylenephosphonic acid) (EDDPO), 1,3-propylenediaminebis(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid) (EDTPO), ethylenediaminetetra(ethylenephosphonic acid), 1,3-propylenediaminetetra(methylenephosphonic acid) (PDTMP), 1,2-diaminopropanetetra(methylenephosphonic acid), or 1,6-hexamethylenediaminetetra(methylenephosphonic acid).

[0097] [ka]

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

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

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

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

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

[0026] to

[0036] of International Publication No. 2018 / 020878 and the compounds ((co)polymers) described in paragraphs

[0031] to

[0046] of International Publication No. 2018 / 030006 can be referenced, and these contents 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. Furthermore, 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, but 1 or more is preferred. As phosphonic acid, the compounds listed as suitable specific examples for each of the compounds represented by formula (P1), formula (P2), and formula (P3) above are preferred, and HEDP is more preferred.

[0104] Phosphonic acids may be used individually or in combination of two or more types. The phosphonic acid content in the cleaning solution is not particularly limited, but is preferably 2% by mass or less, and more preferably 1% by mass or less, relative to the total mass of the cleaning solution. The lower limit is not particularly limited, but is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the cleaning solution. Furthermore, the phosphonic acid content is preferably 40% by mass or less, and more preferably 10% by mass or less, relative to the total mass of the components excluding the solvent in the cleaning solution, in order to achieve superior effects of the present invention. There is no particular lower limit, but it is preferably 0.001% by mass or more, and more preferably 0.01% by mass or more, relative to the total mass of the components excluding the solvent in the cleaning solution.

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

[0106] The organic acid is preferably 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 85 or more is preferred. Furthermore, 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 2 or more is preferred.

[0107] Organic acids may be used individually or in combination of two or more. The cleaning solution preferably contains two or more organic acids for superior cleaning performance. The content of organic acids in the cleaning solution is not particularly limited, but is preferably 10% by mass or less, and more preferably 5% by mass or less, relative to the total mass of the cleaning solution. The lower limit is not particularly limited, but is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the cleaning solution. Furthermore, the content of organic acids is preferably 40% by mass or less, and more preferably 10% by mass or less, relative to the total mass of the components excluding the solvent in the cleaning solution, in order to achieve superior effects of the present invention. There is no particular lower limit, but it is preferably 0.001% by mass or more, and more preferably 0.01% by mass or more, relative to the total mass of the components excluding the solvent in the cleaning solution.

[0108] <Corrosion inhibitor> The cleaning solution may contain a corrosion inhibitor. Furthermore, it is preferable to use a different component from the above-mentioned components as the corrosion inhibitor. Examples of corrosion inhibitors include non-reducing corrosion inhibitors such as heterocyclic compounds having a heterocyclic structure and phosphate ester surfactants; and reducing corrosion inhibitors such as biguanide compounds, ascorbic acid compounds, hydroxylamine compounds, catechol compounds, hydrazide compounds, reducing sulfur compounds, and hydroxycarboxylic acids, as well as their derivatives. Among these, non-reducing corrosion inhibitors are preferred, and heterocyclic compounds or phosphate ester surfactants are more preferred. Corrosion inhibitors with reducing properties are those that have oxidizing properties and contain OH in the cleaning solution. - These are compounds that have the function of oxidizing ions or dissolved oxygen, and are also called oxygen absorbers.

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

[0110] Azole compounds are compounds that contain at least one nitrogen atom and have an aromatic hetero-five-membered ring. The number of nitrogen atoms in the hetero-five-membered ring of the azole compound is not particularly limited, but is preferably 1 to 4, and more preferably 1 to 3. Furthermore, the azole compound may have substituents on the hetero-five-membered ring. Examples of such substituents include a hydroxyl group, a carboxyl group, a mercapto group, an amino group, a C1-C4 alkyl group which may have an amino group, and a 2-imidazolyl group.

[0111] Examples of azole compounds include imidazole compounds in which one of the atoms constituting the azole ring is a nitrogen atom, pyrazole compounds in which two of the atoms constituting the azole ring are nitrogen atoms, thiazole compounds in which one of the atoms constituting the azole ring is a nitrogen atom and the other is a sulfur atom, triazole compounds in which three of the atoms constituting the azole ring are nitrogen atoms, and tetraazole compounds 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-pyrazolecarboxylic acid, 1-methylpyrazole, 3-methylpyrazole, 3-amino-5-hydroxypyrazole, 3-aminopyrazole, and 4-aminopyrazole.

[0114] Examples of thiazole compounds include 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] Preferred azole compounds include imidazole compounds, pyrazole compounds, triazole compounds, or tetrazole compounds, with pyrazole compounds or triazole compounds being more preferred, and 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 being even more preferred.

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

[0119] Examples of phosphate ester surfactants 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, polyoxyethylene dimethylphenyl ether phosphate is preferred as the phosphate ester surfactant.

[0120] As phosphate ester surfactants, compounds described in paragraphs

[0012] to

[0019] of Japanese Patent Publication No. 2011-040502 can also be used, and these contents are incorporated herein by reference.

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

[0034] to

[0055] of Japanese Patent Publication No. 2017-504190, the contents of which are incorporated herein by reference.

[0122] Compounds containing 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)pentan-1,5-bis(5-hexylbiguanide), and 2-(phenyl Luthiomethyl)pentane-1,5-bis(5-phenethylbiguanide), 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) are preferred, and chlorhexidine is more preferred. As salts of compounds having a biguanide group, hydrochloride salts, acetate salts, or gluconates are preferred, with gluconates being more preferred. As the biguanide compound, chlorhexidine gluconate (CHG) is preferred.

[0123] -Ascorbic acid compounds- Ascorbic acid compounds mean 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 esters and ascorbic acid sulfate esters. Ascorbic acid compounds are preferably ascorbic acid, ascorbic acid phosphate ester, or ascorbic acid sulfate ester, with ascorbic acid being more preferred.

[0124] -Hydroxylamine compounds- A hydroxylamine compound means at least one selected from the group consisting of hydroxylamine (NH2OH), hydroxylamine derivatives, and salts thereof. A hydroxylamine derivative means a compound obtained by substituting at least one organic group with hydroxylamine (NH2OH). Salts of hydroxylamine or hydroxylamine derivatives may be inorganic or organic salts of hydroxylamine or hydroxylamine derivatives. Preferably, the salt of hydroxylamine or hydroxylamine derivative is a salt with an inorganic acid in which at least one nonmetal selected from the group consisting of Cl, S, N, and P is bonded to hydrogen, and hydrochloride salts, sulfate salts, or nitrate salts are more preferred.

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

[0126] [ka]

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

[0128] R 5 and R 6 The organic group represented is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group having 1 to 6 carbon atoms may be linear, branched, or cyclic. Also, R 5 and R 6 It is preferable that at least one of them is an organic group (more preferably an alkyl group having 1 to 6 carbon atoms). As the alkyl group having 1 to 6 carbon atoms, an ethyl group or an n-propyl group is preferred, with an ethyl group being more preferred.

[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. Among these, N-ethylhydroxylamine, N,N-diethylhydroxylamine (DEHA), or Nn-propylhydroxylamine are preferred, with DEHA being more preferred.

[0130] -Catechol compounds- Catechol compounds refer to at least one selected from the group consisting of pyrocatechol (benzene-1,2-diol) and catechol derivatives. A catechol derivative refers to a compound obtained by substituting pyrocatechol with at least one substituent. Examples of substituents on a catechol derivative include a hydroxyl group, a carboxyl group, a carboxylic acid ester group, a sulfo group, a sulfonic acid ester group, an alkyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms), and an aryl group (a phenyl group is preferred). The carboxyl group and sulfo group that the catechol derivative has as substituents may be salts with a cation. Furthermore, the alkyl group and aryl group that the catechol derivative has as substituents may have further substituents. Examples of catechol compounds include pyrocatechol, 4-tert-butylcatechol, pyrogallol, gallic acid, methyl gallate, 1,2,4-benzenetriol, and tyron.

[0131] -Hydrazide compounds- Hydrazide compounds refer to compounds obtained by substituting the hydroxyl group of an acid with a hydrazino group (-NH-NH2), and their derivatives (compounds obtained by substituting at least one substituent on the hydrazino group). The hydrazide compound may have two or more hydrazino groups. Examples of hydrazide compounds include carboxylic acid hydrazides and sulfonic acid hydrazides, with carbohydrazides (CHZ) being preferred.

[0132] -Reducing sulfur compounds- The reducing sulfur compound is not particularly limited as long as it contains a sulfur atom and functions as a reducing agent, but examples include cysteine, mercaptosuccinic acid, dithiodiglycerol, bis(2,3-dihydroxypropylthio)ethylene, sodium 3-(2,3-dihydroxypropylthio)-2-methylpropylsulfonate, 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 solution may contain other corrosion inhibitors in addition to the components mentioned above. 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, squalic acid, α-keto acid, adenosine and its derivatives, phenanthroline, resorcinol, hydroquinone, nicotinamide and its derivatives, flavonol and its derivatives, anthocyanins and their 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 tetrazole compounds, triazole compounds, imidazole compounds, pyrazole compounds, and derivatives thereof.

[0135] The corrosion inhibitor may be used alone or in combination of two or more types. In terms of superior corrosion prevention performance, the cleaning solution preferably contains two or more corrosion inhibitors, and more preferably contains three or more corrosion inhibitors. The content of the corrosion inhibitor is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.3 to 5% by mass, based on the total mass of the cleaning solution. Furthermore, the content of the corrosion inhibitor is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 20% by mass, based on the total mass of the components excluding the solvent in the cleaning solution.

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

[0137] Surfactants often have hydrophobic groups selected from aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof. There are no particular limitations on the hydrophobic groups that surfactants possess. In particular, when the hydrophobic group includes an aromatic hydrocarbon group, the number of carbon atoms in the aromatic hydrocarbon group is preferably 6 or more, and more preferably 10 or more. There is no particular upper limit on the number of carbon atoms in the aromatic hydrocarbon group, but it is preferably 20 or less, and more preferably 18 or less. Furthermore, when the hydrophobic group does not contain an aromatic hydrocarbon group and is composed only of aliphatic hydrocarbon groups, the number of carbon atoms in the aliphatic hydrocarbon group is preferably 10 or more, more preferably 12 or more, and even more preferably 16 or more. There is no particular upper limit to the number of carbon atoms in the aliphatic hydrocarbon group, but it is preferably 20 or less, and more preferably 18 or less.

[0138] (Anionic surfactant) Examples of anionic surfactants included in the cleaning solution include phosphonic acid-based surfactants having a phosphonic acid group as their hydrophilic (acidic) group, sulfonic acid-based surfactants having a sulfo group, carboxylic acid-based surfactants having a carboxyl group, and sulfate ester-based surfactants having a sulfate ester group. Among these, it is preferable that the cleaning solution contains an anionic surfactant in order to achieve superior effects according to the present invention.

[0139] -Phosphotic acid-based surfactants- Examples of phosphonic acid-based surfactants include alkylphosphonic acid and polyvinylphosphonic acid. Also, for example, aminomethylphosphonic acid, as described in Japanese Patent Publication No. 2012-057108, is another example.

[0140] -Sulfonic acid-based surfactants- Examples of sulfonic acid-based surfactants include alkyl sulfonic acid, alkylbenzene sulfonic acid, alkyl naphthalene sulfonic acid, alkyl diphenyl ether disulfonic acid, alkyl methyl taurine, sulfosuccinate diester, polyoxyalkylene alkyl ether sulfonic acid, and salts thereof.

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

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

[0143] -Carboxylic acid-based surfactants- Examples of carboxylic acid-based surfactants include alkyl carboxylic acids, alkylbenzene carboxylic acids, and polyoxyalkylene alkyl ether carboxylic acids, as well as salts thereof. The alkyl group of the above-mentioned carboxylic acid-based surfactant is not particularly limited, but alkyl groups having 7 to 25 carbon atoms are preferred, and alkyl groups having 11 to 17 carbon atoms are more preferred. Furthermore, the alkylene group of the polyoxyalkylene alkyl ether carboxylic acid is not particularly limited, but an ethylene group or a 1,2-propanediyl group is preferred. In addition, the number of repeating oxyalkylene groups in the polyoxyalkylene alkyl ether carboxylic acid is preferably 1 to 12, and more preferably 1 to 6.

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

[0145] -Sulfate ester-based surfactants- Examples of sulfate ester-based surfactants include sulfate esters (alkyl ether sulfates), polyoxyalkylene ether sulfates, and salts thereof. The alkyl group of the sulfate ester and polyoxyalkylene ether sulfate ester is not particularly limited, but alkyl groups having 2 to 24 carbon atoms are preferred, and alkyl groups having 6 to 18 carbon atoms are more preferred. The alkylene group in the polyoxyalkylene ether sulfate is not particularly limited, but an ethylene group or a 1,2-propanediyl group is preferred. Furthermore, the number of repeating oxyalkylene groups in the polyoxyalkylene ether sulfate is preferably 1 to 12, and more preferably 1 to 6. Specific examples of sulfate ester 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), polyoxyalkylene alkenyl ethers (e.g., polyoxyethylene oleyl ether), polyoxyethylene alkylphenyl ethers (e.g., polyoxyethylene nonylphenyl ether), polyoxyalkylene glycols (e.g., polyoxypropylene polyoxyethylene glycol), and polyoxyalkylene monoalkylates (monoalkyl fatty acid ester polyoxyalkylenes) (e.g., polyoxyethylene monostearate and polyoxyethylene monooleate). Examples include ethylene monoalkylates, polyoxyalkylene dialkylates (dialkyl fatty acid ester polyoxyalkylenes) (for example, polyoxyethylene distearate and polyoxyethylene diolate, etc.), bispolyoxyalkylene alkylamides (for example, bispolyoxyethylene stearylamide, etc.), sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylamines, glycerin fatty acid esters, oxyethylene oxypropylene block copolymers, acetylene glycol-based surfactants, and acetylene-based polyoxyethylene oxides.

[0147] (cationic surfactant) Examples of cationic surfactants include primary to tertiary alkylamine salts (e.g., monostearylammonium chloride, distearylammonium chloride, and tristearylammonium chloride), and modified aliphatic polyamines (e.g., polyethylene polyamine).

[0148] (Amphoteric surfactant) Examples of the amphoteric surfactant include carboxybetaine (e.g., alkyl-N,N-dimethylaminoacetate betaine, alkyl-N,N-dihydroxyethylaminoacetate betaine, etc.), sulfobetaine (e.g., alkyl-N,N-dimethylsulfonylethyleneammonium betaine, etc.), and imidazolinium betaine (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, and the contents thereof are incorporated herein.

[0150] The surfactant may be used alone or in combination of two or more. When the cleaning liquid contains the surfactant, the content thereof 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. Further, 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 synthesized appropriately using known methods.

[0154] -Acidic compounds- Examples of acidic compounds include inorganic acids. Examples of inorganic acids include hydrochloric acid, sulfuric acid, sulfurous acid, nitric acid, nitrite, phosphoric acid, boric acid, and hexafluorine phosphoric acid. Salts of inorganic acids may also be used, for example, ammonium salts of inorganic acids, more specifically, ammonium chloride, ammonium sulfate, ammonium sulfite, ammonium nitrate, ammonium nitrite, ammonium phosphate, ammonium borate, and ammonium hexafluorine phosphate. As the inorganic acid, sulfuric acid, phosphoric acid, or phosphate is preferred, with sulfuric acid or phosphoric acid being more preferred.

[0155] As for the acidic compound, any salt of an acidic compound that becomes an acid or acid ion (anion) in aqueous solution may be used. The acidic compound may be a commercially available product, or one that has been appropriately synthesized by a known method.

[0156] pH adjusters may be used individually or in combination of two or more types. If the cleaning solution contains a pH adjuster, its content is selected according to the type and amount of other components and the desired pH of the cleaning solution, but is preferably 0.01 to 3% by mass, and more preferably 0.05 to 1% by mass, relative to the total mass of the cleaning solution.

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

[0158] -polymer- The cleaning solution may contain polymers. The polymer described above is composed of components different from those described above. The weight-average molecular weight of the polymer is preferably 200 or more, more preferably 1000 or more, and even more preferably 2000 or more. There is no particular upper limit, but it is preferably 1,000,000 or less, and more preferably 500,000 or less. In particular, when the polymer is a water-soluble polymer as described later, the weight-average molecular weight of the water-soluble polymer is preferably 200 or more, more preferably 1500 or more, and even more preferably 3000 or more. There is no upper limit to the weight-average molecular weight of the water-soluble polymer; for example, it is 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 includes at least one selected from the group consisting of polymer A, which has a weight-average molecular weight of 500 or more and less than 2000, and polymer B, which has a weight-average molecular weight of 2000 or more. The upper limit of the molecular weight of polymer B is not particularly limited, but it is preferably 1,000,000 or less, and more preferably 500,000 or less. In this specification, "weight-average molecular weight" refers to the weight-average molecular weight in terms of 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 repeating units having a carboxyl group (such as repeating units derived from (meth)acrylic acid) or repeating units having an acid anhydride group. The content of repeating units having a carboxyl group or repeating units 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] The polymer is preferably a water-soluble polymer. Furthermore, "water-soluble polymer" refers to a compound in which two or more repeating units are linked together in a linear or network-like manner via covalent bonds, and whose mass that dissolves in 100g of water at 20°C is 0.1g or more.

[0160] Examples of water-soluble polymers include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyvinylsulfonic acid, polyallylsulfonic acid, polystyrenesulfonic 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 with aromatic hydrocarbon groups 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 natural polysaccharides such as hydroxyethylcellulose, carboxymethylcellulose, and modified starch.

[0161] The water-soluble polymer may be a homopolymer or a copolymer obtained by copolymerizing two or more 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. It is also preferable that the water-soluble polymer consists substantially only of structural units derived from monomers selected from the above group. For a polymer to consist substantially only 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% by mass, and more preferably 99 to 100% by mass.

[0162] Polymers may be used individually or in combination of two or more types. If the cleaning solution contains polymers, their content is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.3 to 5% by mass, relative to the total mass of the cleaning solution. Furthermore, the polymer content is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 20% by mass, based on the total mass of the components excluding the solvent in the washing solution. When the polymer content is within the above range, the polymer is appropriately adsorbed onto the substrate surface, contributing to improved corrosion prevention performance of the cleaning solution, and also allowing for a good balance between the viscosity and / or cleaning performance of the cleaning solution.

[0163] -Polyhydroxy compounds with a molecular weight of 500 or more- The cleaning solution may contain polyhydroxy compounds with a molecular weight of 500 or more. The polyhydroxy compounds mentioned above are components different from the components described above. The above polyhydroxy compounds are organic compounds having two or more (e.g., 2 to 200) alcoholic hydroxyl groups in a single molecule. The molecular weight (or weight-average molecular weight if a molecular weight distribution exists) of the above polyhydroxy compound is 500 or more, and preferably between 500 and 3000.

[0164] Examples of the polyhydroxy compounds mentioned above include polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol; oligosaccharides such as mannitriose, cellotriose, gentianose, raffinose, meletitose, cellotetose, and stachyose; and polysaccharides such as starch, glycogen, cellulose, xylose, chitin, and chitosan, and their hydrolysates.

[0165] Furthermore, cyclodextrin is also preferred as the polyhydroxy compound. Cyclodextrins are a type of cyclic oligosaccharide in which multiple D-glucose molecules are linked together by glucosidic bonds, forming a cyclic structure. They are compounds in which five or more glucose molecules (for example, six to eight) are linked together. Examples of cyclodextrins include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, with γ-cyclodextrin being preferred.

[0166] The above polyhydroxy compounds may be used individually or in combination of two or more. If the cleaning solution contains the above-mentioned polyhydroxy compound, its content is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.1 to 3% by mass, based on the total mass of the cleaning solution. Furthermore, the polyhydroxy compound content is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 20% by mass, based on the total mass of the components excluding the solvent in the washing solution.

[0167] The chelating agent is not particularly limited as long as it is an organic acid having the chelating function 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 pyrophosphate and its salts, metaphosphate and its salts, tripolyphosphate and its salts, and hexametaphosphate and its salts.

[0168] Examples of fluorine compounds include those described in paragraphs

[0013] to

[0015] of Japanese Patent Publication No. 2005-150236, the details of which are incorporated herein by reference.

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

[0170] Additives may be used individually or in combination of two or more types. The amount of additives is not particularly limited, but is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.3 to 5% by mass, relative to the total mass of the cleaning solution. Furthermore, the additive content is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 20% by mass, based on the total mass of the components excluding the solvent in the washing solution.

[0171] <Water> The cleaning solution preferably contains water as a solvent. There are no particular restrictions on the type of water used in the cleaning solution, as long as it does not adversely affect the semiconductor substrate; 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 impact on the semiconductor substrate during the manufacturing process. The water content in the cleaning solution may consist of the perhalic acid, halogen acid, and the remainder of the optional components mentioned above. The water content is 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, relative to the total mass of the cleaning solution. There is no particular upper limit, but it is preferably 99% by mass or less, and more preferably 98% by mass or less, relative to the total mass of the cleaning solution.

[0172] [Physical properties of the cleaning solution] <Metal content> In the cleaning solution, the content (measured as 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 ppm by mass or less, and more preferably 1 ppm by mass or less. In the manufacturing of state-of-the-art semiconductor devices, it is anticipated that even higher purity cleaning solutions will be required, so it is even more preferable that the metal content is lower than 1 ppm by mass, i.e., on the order of ppb by mass or less, particularly preferably 100 ppb by mass or less, and most preferably less than 10 ppb by mass. There is no particular lower limit, but 0 is preferred.

[0173] Methods for reducing metal content include, for example, performing purification treatments such as distillation and filtration using ion exchange resins or filters at the stage of raw materials used in the manufacture of the cleaning solution, or at a stage after the manufacture of the cleaning solution. Other methods for reducing metal content include using containers that minimize the leaching of impurities (as described later) to hold the raw materials or the manufactured cleaning solution. Additionally, lining the inner walls of pipes with fluororesin can be used to prevent metal components from leaching out during the manufacturing of the cleaning solution.

[0174] <Coarse particles> The cleaning solution may contain coarse particles, but it is preferable that the content be low. Here, coarse particles refer to particles with a diameter (particle size) of 0.4 μm or more when the particle shape is considered to be spherical. The content of coarse particles in the washing solution is preferably 1,000 or less, and more preferably 500 or less, of particles with a particle size of 0.4 μm or larger per 1 mL of washing solution. There is no particular lower limit, but 0 is an acceptable limit. Furthermore, it is more preferable that the content of particles with a particle size of 0.4 μm or larger, as measured by the measurement method described below, is below the detection limit. Coarse particles contained in the cleaning solution include dust, dirt, organic solids, and inorganic solids that are present as impurities in the raw materials, as well as dust, dirt, organic solids, and inorganic solids that are introduced as contaminants during the preparation of the cleaning solution, and which ultimately remain as particles in the cleaning solution without dissolving. The amount of coarse particles present in the cleaning solution can be measured in the liquid phase using a commercially available measuring device that employs a light scattering method for measuring particles in liquid, with a laser as the light source. Methods for removing coarse particles include purification processes such as filtering, which will be described later.

[0175] The cleaning solution may also be provided as a kit, with its raw materials divided into multiple components.

[0176] [Manufacturing of cleaning solution] The cleaning solution can be manufactured by known methods. The manufacturing method for the cleaning solution is described in detail below.

[0177] <Liquid preparation process> The method for preparing the cleaning liquid is not particularly limited. For example, the cleaning liquid can be produced by mixing the above-mentioned components. The order and / or timing of mixing the above-mentioned components are not particularly limited. For example, after sequentially adding perhalic acid, halic acid, and optional components to a container containing purified pure water, stirring and mixing, and adding a pH adjuster to adjust the pH of the mixed solution, a preparation method can be used. In addition, when adding water and each component to the container, they may be added all at once or divided and added in multiple times.

[0178] The stirring device and stirring method used for preparing the cleaning liquid are not particularly limited, and a device known as a stirrer or a disperser may be used. Examples of stirrers include industrial mixers, portable stirrers, mechanical stirrers, and magnetic stirrers. Examples of dispersers include industrial dispersers, homogenizers, ultrasonic dispersers, and bead mills.

[0179] Mixing of each component in the liquid preparation process of the cleaning liquid, the purification process described later, and storage of the produced cleaning liquid are preferably carried out at 40°C or lower, more preferably at 30°C or lower. Also, 5°C or higher is preferred, and 10°C or higher is more preferred. By performing the liquid preparation, treatment, and / or storage of the cleaning liquid within the above temperature range, the performance can be maintained stably for a long time.

[0180] (Purification process) It is preferable to perform a purification process on any one or more of the raw materials for preparing the cleaning liquid in advance. The purification process is not particularly limited, and known methods such as distillation, ion exchange, and filtration can be mentioned. The degree of purification is not particularly limited, but it is preferably purified until the purity of the raw material reaches 99% by mass or more, and more preferably purified until the purity of the stock solution reaches 99.9% by mass or more.

[0181] Specific methods of purification treatment include, for example, passing the raw material through an ion exchange resin or an RO membrane (Reverse Osmosis Membrane), distilling the raw material, and filtering described below. As purification treatment, a plurality of the above-described purification methods may be combined and implemented. For example, after performing primary purification by passing the raw material through an RO membrane, secondary purification may be carried out by passing it through a purification device composed of a cation exchange resin, an anion exchange resin, or a mixed bed type ion exchange resin. Also, the purification treatment may be carried out multiple times.

[0182] (Filtering) The filter used for filtering is not particularly limited as long as it has been conventionally used for filtration purposes or the like. For example, filters made of fluorine-based resins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide-based resins such as nylon, and polyolefin resins (including high density or ultra-high molecular weight) such as polyethylene and polypropylene (PP) may be mentioned. Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high density polypropylene), fluorine-based resins (including PTFE and PFA), and polyamide-based resins (including nylon) are preferred, and filters made of fluorine-based resins are more preferred. By filtering the raw material using a filter formed of these materials, highly polar foreign substances that are 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 value of the critical surface tension of the filter is the nominal value of the manufacturer. By using a filter with a critical surface tension within the above range, highly polar foreign substances that are likely to cause defects can be effectively removed.

[0184] The pore size of the filter is preferably 2 to 20 nm, and more preferably 2 to 15 nm. This range allows for the reliable removal of fine foreign matter such as impurities and aggregates contained in the raw material while suppressing clogging. The pore size here can be referenced from the filter manufacturer's nominal value.

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

[0186] Furthermore, filtering is preferably performed at room temperature (25°C) or below, more preferably at 23°C or below, and even more preferably at 20°C or below. Also, it is preferably at 0°C or above, more preferably at 5°C or above, and even more preferably at 10°C or above. By performing 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 the kit or the diluted solution described later) can be filled into any container and stored, transported, and used, provided that corrosiveness or other issues do not pose a problem.

[0188] As for the container, a container with a high degree of cleanliness inside and suppressed elution of impurities from the inner wall of the container's compartment into each liquid is preferred for semiconductor applications. Examples of such containers include various commercially available containers for semiconductor cleaning solutions, such as the "Clean Bottle" series from Aicello Chemical Co., Ltd. and the "Pure Bottle" from Kodama Resin Industry Co., Ltd., but are not limited to these. Furthermore, as a container for holding the cleaning solution, it is preferable that the parts in contact with the liquid, such as the inner wall of the container, are made of a fluororesin (perfluororesin) or a metal that has been treated to prevent rust and metal leaching. 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 from a different resin, or from a metal that has been treated to prevent rust and metal leaching, such as stainless steel, Hastelloy, Inconel, and Monel.

[0189] Among the different resins mentioned above, fluororesins (perfluororesins) are preferred. By using a container with an inner wall made of a fluororesin, the occurrence of problems such as the elution of ethylene or propylene oligomers can be suppressed compared to a container with an inner wall made of polyethylene resin, polypropylene resin, or polyethylene-polypropylene resin. Specific examples of containers with inner walls made of fluororesin include, for example, the FluoroPurePFA composite drum manufactured by Entegris. Containers described on page 4 of Japanese Patent Publication No. 3-502677, page 3 of International Publication No. 2004 / 016526, and pages 9 and 16 of International Publication No. 99 / 46309 can also be used.

[0190] In addition to the fluororesin mentioned above, quartz and electropolished metal materials (i.e., electropolished metal materials) are also preferably used for the inner wall of the container. The metal material used in the manufacture of the electropolished metal material described above 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% by mass of the total mass of the metal material. Examples include stainless steel and nickel-chromium alloys. The combined content of chromium and nickel in the metallic material is more preferably 30% by mass or more relative to the total mass of the metallic material. While there are no particular upper limits on the total chromium and nickel content in the metallic material, it is generally preferable to use 90% by mass or less.

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

[0011] -

[0014] of Japanese Patent Publication No. 2015-227501 and paragraphs

[0036] -

[0042] of Japanese Patent Publication No. 2008-264929 can be used.

[0192] These containers are preferably cleaned inside before being filled with the cleaning solution. The cleaning solution used is preferably one in which the amount of metal impurities is reduced. The cleaning solution may be bottled in containers such as gallon bottles or coated bottles after production for transport and storage.

[0193] To prevent changes in the components of the washing solution during storage, the container may be purged with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. Gases with a low water content are particularly preferred. During transportation and storage, the solution may be stored at room temperature, but the temperature may be controlled within the range of -20°C to 20°C to prevent deterioration.

[0194] (Cleanroom) It is preferable that all handling, including the manufacture of the cleaning solution, opening and cleaning of the container, filling of the cleaning solution, processing analysis, and measurement, be carried out in a cleanroom. The cleanroom should preferably meet the 14644-1 cleanroom standard. It is preferable that it meets one of the ISO (International Organization for Standardization) Class 1, ISO Class 2, ISO Class 3, and ISO Class 4 standards, more preferably ISO Class 1 or ISO Class 2 standards, and even more preferably ISO Class 1 standards.

[0195] <Dilution process> Preferably, the cleaning solution described above is subjected to a dilution step in which it is diluted with a diluent such as water before being used to clean the semiconductor substrate.

[0196] In the dilution process, the dilution ratio of the cleaning liquid may be appropriately adjusted according to the type and content of each component, as well as the semiconductor substrate or the like to be cleaned. However, the ratio of the diluted cleaning liquid to the cleaning liquid before dilution is preferably 10 to 10,000 times, more preferably 20 to 3,000 times, and still more preferably 50 to 1,000 times in terms of volume ratio. In terms of further excellent effects of the present invention, the cleaning liquid is preferably diluted with water.

[0197] The specific method of the dilution process for diluting the cleaning liquid is not particularly limited and may be carried out according to the above-mentioned liquid preparation process of the cleaning liquid. The stirring device and the stirring method used in the dilution process are also not particularly limited and may be carried out using the known stirring devices mentioned in the above-mentioned liquid preparation process of the cleaning liquid.

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

[0199] [Use of the cleaning liquid] The cleaning liquid is used in a cleaning process for cleaning a semiconductor substrate subjected to a chemical mechanical polishing (CMP) treatment. Further, the cleaning liquid can also be used for cleaning a semiconductor substrate in the manufacturing process of a semiconductor substrate. Among them, when the semiconductor substrate contains Ru-containing substances and RuO2-containing substances, this treatment method is preferably used. For cleaning a semiconductor substrate, a diluted cleaning liquid obtained by diluting the cleaning liquid may be used.

[0200] [Object to be cleaned] Examples of the object to be cleaned with the cleaning liquid include a semiconductor substrate having a metal-containing substance. In this specification, "on a semiconductor substrate" includes, for example, the front and back surfaces, sides, and grooves of the semiconductor substrate. Furthermore, "metal-containing material on a semiconductor substrate" includes not only cases where the metal-containing material is directly on the surface of the semiconductor substrate, but also cases where the metal-containing material is present on the semiconductor substrate via other layers. A semiconductor substrate containing at least one selected from the group consisting of Ru-containing materials and RuO2-containing materials is preferred as the object to be cleaned. An example of the above-mentioned semiconductor substrate is a laminate of a Ru-containing material and a RuO2-containing layer formed on the surface of the Ru-containing material.

[0201] Examples of metals included in the metal-containing material 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] A metal-containing substance can be any substance that contains a metal (metal atom), such as elemental metal M, alloys containing metal M, oxides of metal M, nitrides of metal M, and oxynitrides of metal M. Furthermore, the metal-containing material may be a mixture containing two or more of these compounds. The above oxides, nitrides, and oxynitrides may also be composite oxides, composite nitrides, and composite oxynitrides that contain metals. The content of metal atoms in the metal-containing material is preferably 10% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more, based on the total mass of the metal-containing material. The upper limit is 100% by mass or less, since the metal-containing material may be the metal itself.

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

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

[0205] Specific examples of wafers that constitute semiconductor substrates include silicon (Si) wafers, silicon carbide (SiC) wafers, silicon-based wafers 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 pentavalent atoms (e.g., phosphorus (P), arsenic (As), and antimony (Sb)), or a p-type silicon wafer doped with trivalent atoms (e.g., boron (B), and gallium (Ga)). The silicon of the silicon wafer may be amorphous silicon, single-crystal silicon, polycrystalline silicon, or polysilicon. In particular, the cleaning solution is useful for wafers made of silicon-based materials such as silicon wafers, silicon carbide wafers, and silicon-containing resin wafers (glass epoxy wafers).

[0206] The semiconductor substrate may have an insulating film on the wafer described above. Specific examples of insulating films include silicon oxide films (e.g., silicon dioxide (SiO2) films and tetraethyl orthosilicate (Si(OC2H5)4) films (TEOS films), etc.), 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) films and silicon carbide (SiC) films, etc.).

[0207] Examples of metal films on semiconductor substrates include metal films 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, and more preferably has a metal film containing ruthenium. Furthermore, the semiconductor substrate may also have a metal film containing tungsten.

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

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

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

[0211] Examples of tungsten-containing films (metal films with tungsten as the main component) include metal films made solely of tungsten (tungsten metal films) and metal films made of alloys of tungsten and other metals (tungsten alloy metal films). Specific examples of tungsten alloy metal films include, for example, tungsten-titanium alloy metal films (WTi alloy metal films) and tungsten-cobalt alloy metal films (WCo alloy metal films). Tungsten-containing films are commonly used as barrier metals.

[0212] There are no particular restrictions on the method for forming the above-mentioned insulating film, copper-containing wiring film, cobalt-containing film, and tungsten-containing film on a wafer constituting a semiconductor substrate, as 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, for example, a process of flattening the surface of a substrate having a metal wiring film, a barrier metal, and an insulating film by a combined action of chemical action and mechanical polishing using a polishing slurry containing polishing fine particles (abrasives). On the surface of a semiconductor substrate subjected to the CMP process, impurities such as abrasives (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 the Transactions of the Japan Society for Precision Engineering 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 process for cleaning a semiconductor substrate using a cleaning solution is not particularly limited as long as it is a known method performed on a CMP-treated semiconductor substrate. Various methods commonly used in this field may be employed, such as brush scrubbing, where a cleaning member such as a brush is physically brought into contact with the surface of the semiconductor substrate while the cleaning solution is supplied; immersion cleaning, where the semiconductor substrate is immersed in the cleaning solution; spin (dropping) cleaning, where the cleaning solution is dripped onto the semiconductor substrate while it is rotated; and spray cleaning, where the cleaning solution is sprayed onto the substrate. In immersion cleaning, ultrasonic treatment of the cleaning solution in which the semiconductor substrate is immersed is preferable, as this can further reduce impurities remaining on the surface of the semiconductor substrate. The above cleaning process may be performed only once or two or more times. If cleaning is performed two or more times, the same method may be repeated, or different methods may be combined.

[0216] For cleaning semiconductor substrates, either a single-wafer method or a batch method may be employed. The single-wafer method generally involves processing semiconductor substrates one at a time, while the batch method generally involves processing multiple semiconductor substrates simultaneously.

[0217] The temperature of the cleaning solution used to clean semiconductor substrates is not particularly limited, as long as it is within the range of temperatures commonly used in this field. Generally, cleaning is performed at room temperature (25°C), but the temperature can be arbitrarily selected to improve cleaning performance and minimize damage to the materials. The cleaning solution temperature is preferably 10 to 60°C, and more preferably 15 to 50°C.

[0218] The cleaning time for cleaning semiconductor substrates cannot be generalized as it depends on the type and amount of components contained in the cleaning solution, but practically speaking, 10 seconds to 2 minutes is preferred, 20 seconds to 1 minute 30 seconds is more preferred, and 30 seconds to 1 minute is even more preferred.

[0219] The supply rate (feed rate) of the cleaning solution in the semiconductor substrate cleaning process is not particularly limited, but 50 to 5000 mL / min is preferred, and 500 to 2000 mL / min is more preferred.

[0220] In cleaning semiconductor substrates, a mechanical stirring method may be used to further enhance the cleaning ability of the cleaning solution. Examples of mechanical stirring methods include circulating the cleaning solution over a semiconductor substrate, flowing or spraying the cleaning solution over a semiconductor substrate, and stirring the cleaning solution using ultrasound or megasonic waves.

[0221] After cleaning the semiconductor substrate as described above, a step of rinsing the semiconductor substrate with a solvent to clean it (hereinafter referred to as the "rinsing step") may be performed. The rinsing step is performed immediately after the semiconductor substrate cleaning step, and preferably involves rinsing with a rinsing solution for 5 seconds to 5 minutes. The rinsing step may also be performed using the mechanical stirring method described above.

[0222] Examples of rinse solutions include water (preferably deionized (DI) water), methanol, ethanol, isopropyl alcohol, N-methylpyrrolidinone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Alternatively, an aqueous rinse solution with a pH greater than 8 (such as diluted aqueous ammonium hydroxide) may be used. The method for bringing the rinsing solution into contact with the semiconductor substrate can be similarly applied to the method for bringing the cleaning solution into contact with the semiconductor substrate as described above.

[0223] Furthermore, a drying process may be performed after the rinsing process to dry the semiconductor substrate. The drying method is not particularly limited and includes, for example, spin drying, a method of passing a drying gas over a semiconductor substrate, a method of heating the substrate with a heating means such as a hot plate or infrared lamp, Marangoni drying, Rotagoni drying, IPA (isopropyl alcohol) drying, and any combination thereof. [Examples]

[0224] The present invention will be described in more detail below based on examples. The materials, amounts used, and proportions shown in the following examples can be modified 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 examples shown below.

[0225] In the following examples, the pH of the washing solution was measured at 25°C in accordance with JIS Z8802-1984 using a pH meter (Horiba, Ltd., model "F-74"). Furthermore, in the preparation of the cleaning solutions for the examples and comparative examples, the handling of containers, preparation, filling, storage, and analytical measurements of the cleaning solutions were all carried out in a cleanroom meeting ISO Class 2 or lower standards.

[0226] [Ingredients of cleaning solution] The following compounds were used to manufacture the cleaning solution. All components used in the examples were classified as semiconductor grade or equivalent high-purity grade.

[0227] [Perhalic acid] • Orthoperiodate: Manufactured by Fujifilm Wako Pure Chemical Corporation [Halogenated acids] • Iodate: Manufactured by Fujifilm Wako Pure Chemical Corporation [Organic acid] • Diethylenetriaminepentaacetic acid (DTPA): Manufactured by Fujifilm Wako Pure Chemical Corporation • Ethylenediaminetetraacetic acid (EDTA): Manufactured by Kirest Co., Ltd. • 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP): Thermophos "Dequest 2000" • Citric acid (CA): Manufactured by Fuso Chemical Industries Co., Ltd. [Corrosion inhibitor] <Phosphate ester-based surfactants> • (CH3)2Ph-(OE)6OPO3H2: Manufactured by 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: Manufactured by Fujifilm Wako Pure Chemical Corporation [Organic base compounds] <First amine> • 2-amino-2-methyl-1-propanol (AMP): Manufactured by Fujifilm Wako Pure Chemical Corporation <Second Amine> • Tetraethylammonium hydroxide (TEAH): Manufactured by Fujifilm Wako Pure Chemical Corporation • Tetrabutylammonium hydroxide (TBAH): Manufactured by Fujifilm Wako Pure Chemical Corporation • Tetrapropylammonium hydroxide (TPAH): Manufactured by Fujifilm Wako Pure Chemical Corporation • Tetrabutylphosphonium Hydroxide (TBPH): Manufactured by Fujifilm Wako Pure Chemical Corporation • Diazabicycloundecene (DBU): Manufactured by Fujifilm Wako Pure Chemical Corporation [pH adjuster] • Sulfuric acid (H2SO4): Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. [Additives] <polymer> • Polyacrylic acid (Mw=700,000): Manufactured by Toagosei Co., Ltd., product name "Jurimar AC-10H" • Polyacrylic acid (Mw=55,000): Manufactured by Toagosei Co., Ltd., product name "Jurimar AC-10L" • Polyacrylic acid (Mw=6,000): Manufactured by Toagosei Co., Ltd., product name "Aron A-10SL" • Polyacrylic acid (Mw = 1000 or more and less than 2000): Manufactured by Aldrich, trade name "Poly(acrylic acid)" • Polymaleic acid (Mw=2,000): Manufactured by NOF Corporation, product name "Non-Pole PWA-50W"

[0228] [Manufacturing of cleaning solution] Next, the method for producing the cleaning solution will be explained using Example 1 as an example. Ultrapure water was mixed with orthoperiodic acid, iodic acid, tetraethylammonium hydroxide (TEAH), and diazabicycloundecene (DBU) in the amounts specified in Tables 1 and 2, respectively. Then, sulfuric acid was added to adjust the pH of the prepared washing solution to 11. The resulting mixture was thoroughly stirred with a stirrer to obtain the washing solution of Example 1.

[0229] Cleaning solutions for Examples 2 to 51 and Comparative Example 1, having the compositions shown in Tables 1 and 2, were prepared according to the manufacturing method of Example 1.

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

[0231] [Evaluation of removal performance] The cleaning solution prepared using the method described above was used to evaluate its removal performance on metal films containing ruthenium or ruthenium oxide. Two mL of the washing solution from each example and comparative example was taken and diluted 100 times by volume with ultrapure water to prepare a diluted washing solution (200 mL). A 12-inch diameter wafer with a metal film containing ruthenium or ruthenium oxide on its surface was cut, and wafer coupons measuring 10 nm thick and 2 cm x 2 cm were prepared. Wafer coupons were immersed in a diluted washing solution, and each metal film was stirred for 30 minutes at room temperature at a stirring speed of 250 rpm. After stirring, each metal film was observed using the method described below, and the average value of the lost film thickness was calculated to determine the removal rate per unit time. Then, from the removal rates for each metal film, the ratio of the removal rate of RuO2 to the removal rate of Ru (RuO2 / Ru) was calculated. Surface observation was performed using a Review SEM observation system manufactured by Applied Materials Technology, with thickness measurements taken at 100 random locations. The cleaning solution's removal performance was evaluated according to the following criteria. A faster RuO2 removal rate is preferable, and a higher RuO2 / Ru ratio is preferable. (RuO2 evaluation criteria (RuO2 removal rate)) A: Removal rate of 2A / min or higher B: Removal rate is 1 A / min or more but less than 2 A / min C: Removal rate less than 1 A / min (RuO2 / Ru evaluation criteria (RuO2 / Ru selection ratio)) A: RuO2 / Ru is 5 or greater B:RuO2 / Ru is between 3 and 5 (inclusive). C:RuO2 / Ru is between 1 and 3 (inclusive). 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, the cleaning solution of the present invention was confirmed to have excellent selectivity in removing RuO2.

[0236] Comparison with Examples 22-29 and 31 confirmed that the effect is superior when the pH value of the cleaning solution used is between 2.0 and 12.0. From a comparison with Examples 1-8 and 17-20, it was confirmed that the effect is superior when the mass ratio of perhalic acid content to halogenic acid content is between 0.00001 and 50. A comparison of Example 29 and Example 30 confirmed that the effect is even better when an organic base compound is further included. A comparison of Examples 47-51 confirmed that the effect was superior when polymer B was included.

Claims

1. A cleaning solution for semiconductor substrates that have undergone chemical mechanical polishing, It contains perhalates and halogens. The mass ratio of the perhalic acid content to the halogenic acid content is 0.00001 to 0.

9. It further contains organic base compounds, A washing 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 Both represent organic groups. １ , R ２ , and R ３ Some of these may be bonded to each other to form a non-aromatic ring which may have substituents.

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 This represents an alkyl group which may have a hydroxyl group or a phenyl group as a substituent. The four R's ４ They may be identical or different from one another.

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% by mass or more and 25% by mass or less based on 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% by mass or more and 50% by mass or less, based on 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 2.0 to 12.

0.

7. The cleaning solution according to any one of claims 1 to 6, wherein the mass ratio of the content of the perhalic acid to the content of the halogenic acid is 0.00001 to 0.

25.

8. A 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 comprises at least one selected from the group consisting of a carboxyl group and a phosphonic acid group.

10. A cleaning solution according to any one of claims 1 to 9, further comprising at least one selected from the group consisting of a corrosion inhibitor, a surfactant, 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.

11. It also contains a corrosion inhibitor. The cleaning solution according to any one of claims 1 to 10, wherein the corrosion inhibitor is a heterocyclic compound.

12. The cleaning solution according to claim 11, wherein the corrosion inhibitor comprises at least one selected from the group consisting of tetrazole compounds, triazole compounds, imidazole compounds, pyrazole compounds, and derivatives thereof.

13. It further contains surfactants, The cleaning solution according to any one of claims 1 to 12, wherein the surfactant is an anionic or nonionic surfactant.

14. It further contains polymer B with 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 using a cleaning solution according to any one of claims 1 to 14.

Images