Chemical solution, method for cleaning semiconductor substrate, and method for producing electronic device

Abstract

The present invention addresses the problem of providing a chemical solution that, when used for cleaning a semiconductor substrate which contains a copper-containing material and which has been subjected to a chemical-mechanical polishing treatment, exhibits excellent corrosion-inhibiting properties with respect to copper and excellent removability of residue on the copper-containing material. The present invention also addresses the problem of providing a method for cleaning a semiconductor substrate and a method for producing an electronic device which use the chemical solution.　A chemical solution according to the present invention comprises: an alkali source; at least one specific phosphorus-atom-containing compound selected from the group consisting of phosphorus-atom-containing acids and salts thereof; at least one specific compound selected from the group consisting of a first compound and a second compound; and water, wherein pH is not more than 11.50, the first compound has at least two groups selected from the group consisting of an amino group and a hydroxyl group, and the second compound has at least two groups selected from the group consisting of a thiol group and a thioether group.

Description

Chemical solutions, methods for cleaning semiconductor substrates, and methods for manufacturing electronic devices.

[0001] This invention relates to a chemical solution, a method for cleaning a semiconductor substrate, and a method for manufacturing an electronic device.

[0002] In the semiconductor field, with the remarkable increase in integration and performance, even minute amounts of impurities (contaminations) and / or attached substances (particles) can significantly affect the performance of equipment and, consequently, the yield of products. Various types of contaminations and particles (hereinafter also referred to as residues) can be generated in each manufacturing process of semiconductor devices. To remove such residues, a cleaning process for semiconductor substrates is appropriately carried out during semiconductor manufacturing. For example, as one step in the manufacturing of a semiconductor device, a chemical mechanical polishing process may be performed to planarize the surface of a semiconductor substrate having a metal wiring film, barrier metal, and insulating film using a polishing slurry containing polishing particles (e.g., silica and alumina). In chemical mechanical polishing, metal components derived from the polishing particles used in the chemical mechanical polishing process, the polished wiring metal film and / or barrier metal, and organic components contained in the polishing slurry tend to remain on the surface of the semiconductor substrate after polishing. For this reason, a cleaning process is generally carried out after chemical mechanical polishing to clean the semiconductor substrate using a cleaning composition.

[0003] As an example of such a composition, Patent Document 1 discloses "a composition comprising an aluminum, cobalt, or copper corrosion inhibitor selected from a) water; b) an etchant compound; c) a reducing agent; and d) a phosphorus-containing compound of a predetermined structure, wherein the pH of the composition is greater than about 8."

[0004] International Publication No. 2022 / 221497

[0005] The inventors of the present invention investigated the application of the chemical solution described in Patent Document 1 to the cleaning of a semiconductor substrate containing copper that had undergone chemical mechanical polishing. They found that it was not possible to achieve both inhibition of copper corrosion and removal of residue from the copper-containing material, and that further improvements were necessary.

[0006] Therefore, the object of the present invention is to provide a chemical solution that exhibits excellent corrosion suppression properties for copper and excellent removal properties for residues on copper-containing materials when used to clean a semiconductor substrate containing copper-containing materials that has undergone chemical mechanical polishing. Furthermore, the object of the present invention is to provide a method for cleaning a semiconductor substrate using the above chemical solution, and a method for manufacturing an electronic device.

[0007] As a result of diligent research to solve the above problems, the inventors have found that the problems can be solved by the following configuration.

[0008] [1] A chemical solution comprising an alkali source, at least one specific phosphorus atom-containing compound selected from the group consisting of phosphorus atom-containing acids and salts thereof, at least one specific compound selected from the group consisting of a first compound and a second compound, and water, wherein the pH is 11.5 or less, the first compound has two or more groups selected from the group consisting of amino groups and hydroxyl groups, and the second compound has two or more groups selected from the group consisting of thiol groups and thioether groups. [2] The chemical solution according to [1], wherein the alkali source is a quaternary ammonium compound. [3] The chemical solution according to [1] or [2], wherein the alkali source is an ethyltrimethylammonium compound. [4] The chemical solution according to any one of [1] to [3], wherein the specific phosphorus atom-containing compound includes one or more selected from the group consisting of phosphorus atom-containing oxoacids and salts thereof. [5] The chemical solution according to any one of [1] to [4], wherein the specific phosphorus atom-containing compound includes one or more selected from the group consisting of phosphoric acid and salts thereof. [6] The drug solution according to any one of [1] to [5], wherein the specified phosphorus atom compound comprises one or more selected from the group consisting of phosphoric acid, phosphorous acid, and dihydrogen phosphate-aminoethyl. [7] The drug solution according to any one of [1] to [6], wherein the first compound has two or three groups selected from the group consisting of amino groups and hydroxyl groups. [8] The drug solution according to any one of [1] to [7], wherein the first compound comprises one or more selected from compounds having two or more amino groups, and compounds having one or more amino groups and one or more hydroxyl groups. [9] The drug solution according to [8], wherein in the compound having one or more amino groups and one or more hydroxyl groups, the number of hydroxyl groups is 1 to 2.

[10] The drug solution according to any one of [1] to [9], wherein the second compound has two or three or more groups selected from the group consisting of thiol groups and thioether groups.

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

[10] , wherein the second compound contains one or more selected from compounds having two or more thiol groups and compounds having one or more thiol groups and one or more thioether groups.

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

[11] , wherein the first compound comprises one or more selected from the group consisting of N-ethylethylenediamine, 2-dimethylamino-2-methyl-1-propanol, propylene glycol, and monoethanolamine.

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

[12] , wherein the second compound comprises dithiothreitol.

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

[13] , further comprising a corrosion inhibitor.

[15] The chemical solution according to

[14] , wherein the corrosion inhibitor comprises a purine compound.

[16] The chemical solution according to

[14] , wherein the corrosion inhibitor comprises adenine.

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

[16] , used for cleaning a semiconductor substrate containing copper that has been subjected to chemical mechanical polishing.

[18] A method for cleaning a semiconductor substrate, comprising the step of bringing a semiconductor substrate containing copper, which has been subjected to chemical mechanical polishing, into contact with a chemical solution described in any of [1] to

[16] .

[19] A method for manufacturing an electronic device, comprising the method for cleaning a semiconductor substrate described in

[18] .

[0009] According to the present invention, when used to clean a semiconductor substrate containing copper that has undergone chemical mechanical polishing, it is possible to provide a chemical solution that exhibits excellent corrosion suppression of copper and excellent removal of residues on the copper-containing material. Furthermore, according to the present invention, a method for cleaning a semiconductor substrate using the above chemical solution and a method for manufacturing an electronic device can also be provided.

[0010] The present invention will be described in detail below. The following descriptions of constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.

[0011] In this specification, numerical ranges expressed using "~" mean a range that includes the numbers before and after "~" as the lower and upper limits. In this specification, "total mass of components excluding the solvent in the processing solution" means the total mass of all components contained in the processing solution other than the solvent, such as water and organic solvents. In this specification, if there are two or more types of a certain component, the "content" of that component means the total content of those two or more types of components. Unless otherwise specified, the compounds described in this specification may contain structural isomers, optical isomers, and isotopes. Furthermore, structural isomers, optical isomers, and isotopes may be contained individually or in pairs or more.

[0012] In this specification, when there are multiple substituents and linking groups (hereinafter referred to as substituents, etc.) indicated by specific symbols, or when multiple substituents, etc. are specified simultaneously, it means that each substituent, etc. may be identical or different from the others. The same applies to the specification of the number of substituents, etc. In this specification, the bonding direction of divalent groups is not limited unless otherwise specified. For example, in a compound represented by the formula "X-Y-Z", if Y is -COO-, Y may also be -CO-O- or -O-CO-. Furthermore, the above compound may also be "X-CO-O-Z" or "X-O-CO-Z".

[0013] In this specification, "ppm" means "parts-per-million (10) －６ ) means "ppb" is "parts-per-billion (10 －９ ) means "ppt" is "parts-per-trillion (10 －１２ This means ) ). In this specification, "weight-average molecular weight" means the weight-average molecular weight on a polyethylene glycol basis as measured by GPC (gel permeation chromatography). In this specification, 1 Å (angstrom) corresponds to 0.1 nm.

[0014] [Medicinal Solution] The medicinal solution of the present invention will be described in detail below. The medicinal solution of the present invention (hereinafter also simply referred to as "this medicinal solution") comprises an alkali source, at least one specific phosphorus atom-containing compound selected from the group consisting of phosphorus atom-containing acids and salts thereof, at least one specific compound selected from the group consisting of a first compound and a second compound, and water, wherein the pH is 11.5 or less, the first compound has two or more groups selected from the group consisting of amino groups and hydroxyl groups, and the second compound has two or more groups selected from the group consisting of thiol groups and thioether groups.

[0015] The reason why a composition having the above configuration can solve the problems of the present invention is not necessarily clear, but the inventors speculate as follows. Note that the following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than those described below, it is still within the scope of the present invention. This chemical solution is adjusted to have a pH of 11.5 or lower, making it less likely to corrode copper-containing materials. On the other hand, when a chemical solution with a low pH is used to clean a semiconductor substrate containing copper-containing materials that has undergone chemical mechanical polishing, the removal of copper-containing residue is often poor. In contrast, this chemical solution is thought to exhibit good residue removal performance by containing a specific compound. Semiconductor substrates containing copper-containing materials that have undergone chemical mechanical polishing often have residue adhering to the copper-containing materials due to some of the copper-containing materials ionizing and interacting with the residue (for example, forming complexes). Examples of residue include organic substances such as corrosion inhibitors used to prevent corrosion of copper-containing materials during chemical mechanical polishing. The specific compound contained in this solution exhibits excellent interaction with ionized copper-containing materials due to the presence of a predetermined group. It functions to separate the residue from the copper-containing materials and to exchange them with the residue to form an interaction with the copper-containing materials. As a result, this solution is presumed to be excellent at removing residue from copper-containing materials. Furthermore, it is presumed that the phosphorus-containing acid contained in this solution functions to protect the copper-containing materials from the specific compound (suppressing corrosion by the specific compound) by adsorbing onto the surface of the copper-containing materials. Due to these mechanisms of action, when this solution is used to clean semiconductor substrates containing copper-containing materials that have undergone chemical mechanical polishing, it can achieve both inhibition of copper corrosion and removal of residue from the copper-containing materials.

[0016] Hereinafter, when used for cleaning semiconductor substrates containing copper that have undergone chemical mechanical polishing, if at least one of the ability to suppress copper corrosion and the ability to remove residues on the copper-containing material is superior, this is also referred to as "the effect of the present invention is superior."

[0017] The various components and properties of this drug solution are described below.

[0018] [Alkali Source] This chemical solution contains an alkali source. Note that the alkali source is a compound different from the specific phosphorus atom-containing compound and specific compound described later. An alkali source is a compound that exhibits basicity in aqueous solution, and examples include basic inorganic compounds and basic organic compounds. Examples of basic inorganic compounds include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkaline earth metal hydroxides. Examples of basic organic compounds include quaternary ammonium compounds.

[0019] <Quaternary Ammonium Compounds> Quaternary ammonium compounds are compounds composed of a quaternary ammonium cation and anion, in which four hydrocarbon groups (preferably alkyl groups) are substituted on a nitrogen atom. Examples of quaternary ammonium compounds include quaternary ammonium hydroxide, quaternary ammonium fluoride, quaternary ammonium bromide, quaternary ammonium chloride, quaternary ammonium iodide, quaternary ammonium acetate, and quaternary ammonium carbonate. Among quaternary ammonium compounds, quaternary ammonium hydroxide is preferred, and the compound represented by the following formula (a1) is more preferred.

[0020]

[0021] In the above formula (a1), R ａ１ ~R ａ４ Each of these independently represents an alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aralkyl group having 7 to 16 carbon atoms, or a hydroxyalkyl group having 1 to 16 carbon atoms. ａ１ ~R ａ４At least two of them may be bonded to each other to form a ring structure. The alkyl group having 1 to 16 carbon atoms is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. The aryl group having 6 to 16 carbon atoms is preferably a phenyl group or a naphthyl group. The aralkyl group having 7 to 16 carbon atoms preferably has a structure in which one hydrogen atom of a linear or branched alkyl group having 1 to 10 carbon atoms is substituted with an aryl group (preferably a phenyl group), more preferably a structure in which one hydrogen atom of a linear or branched alkyl group having 1 to 6 carbon atoms is substituted with an aryl group (preferably a phenyl group), and examples thereof include a benzyl group. The hydroxyalkyl group having 1 to 16 carbon atoms is preferably a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms, more preferably a linear or branched hydroxyalkyl group having 1 to 6 carbon atoms. The number of hydroxy groups is not particularly limited and may be 1 or more.

[0022] R ａ１ ~R ａ４ Among them, a linear or branched alkyl group having 1 to 6 carbon atoms or a linear or branched hydroxyalkyl group having 1 to 6 carbon atoms is preferable, and R ａ１ ~R ａ４ represents a linear or branched alkyl group having 1 to 6 carbon atoms or a linear or branched hydroxyalkyl group having 1 to 6 carbon atoms, and moreover, it is more preferable that the total number of carbon atoms in R ａ１ ~R ａ４ is 5 or more.

[0023] Specific examples of the quaternary ammonium compound include ethyltrimethylammonium hydroxide (ETMAH), trihydroxyethylmethylammonium hydroxide (THEMAH), dimethyldiethylammonium hydroxide (DMDEA), methyltriethylammonium hydroxide (MTEAH), tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), and tetrabutylammonium hydroxide (TBAH), 2-hydroxyethyltrimethylammonium hydroxide (choline), 2-hydroxyethyltrimethylammonium chloride, 2-hydroxypropyltrimethylammonium hydroxide (2-methylcholine), and tetraalkylammonium compounds such as 2-hydroxypropyltrimethylammonium chloride, and benzyltrimethylammonium hydroxide (BTMAH).

[0024] As the alkali source, among others, an ethyltrimethylammonium compound is preferable, and ethyltrimethylammonium hydroxide (ETMAH) is more preferable.

[0025] The alkali source may be used alone or in combination of two or more. The content of the alkali source can be selected according to the types and amounts of other components and the pH of the target composition. For example, the content of the alkali source is preferably 0.2 to 3% by mass, more preferably 0.5 to 2% by mass, and still more preferably 0.8 to 1% by mass with respect to the total mass of the chemical solution. The content of the alkali source is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and still more preferably 40 to 70% by mass with respect to the total mass excluding the solvent of the chemical solution.

[0026] [Specific Phosphorus Atom-Containing Compound] This chemical solution contains at least one compound (specific phosphorus atom-containing compound) selected from the group consisting of phosphorus atom-containing acids and their salts. A phosphorus atom-containing acid is a compound that contains a phosphorus atom and has an acid group. The phosphorus atom-containing acid is preferably a phosphorus atom-containing oxoacid in that it can exhibit good pH buffering ability in a predetermined pH range and the effects of the present invention are more excellent. A phosphorus atom-containing oxoacid is intended to be a compound in which an oxo group (=O) and a hydroxy group (-OH) are bonded to the phosphorus atom and the hydroxy group can donate a proton. The number of hydroxy groups in the phosphorus atom-containing oxoacid is not particularly limited as long as it is 1 or more, and examples include 1 to 4. Examples of the phosphorus atom-containing oxoacid include phosphoric acid, phosphonic acid (tautomer of phosphorous acid), diphosphoric acid, triphosphoric acid, polyphosphoric acid (e.g., tripolyphosphoric acid), phosphorus acid group-containing compounds, and phosphonic acid group-containing compounds, etc.

[0027] In the phosphorus acid group-containing compound, the number of phosphorus acid groups is not particularly limited as long as it is 1 or more, and examples include 1 to 4. Examples of the phosphorus acid group-containing compound include a phosphoric acid monoester compound which may have a substituent (a compound in which one of the hydrogen atoms in the hydroxy group of phosphoric acid is substituted with an organic group), and a phosphoric acid amide monoester compound which may have a substituent (one of the hydroxy groups of phosphoric acid is substituted with a -NR ２ group (R represents a hydrogen atom or an organic group. Two Rs may combine to form a ring which may have a substituent)). Examples of the phosphoric acid monoester compound include a phosphoric acid monoalkyl ester compound. The above alkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms. Also, the above alkyl group is preferably linear or branched. Also, the phosphorus acid group-containing compound may have a substituent. Examples of the substituent include an unsubstituted amino group and a substituted amino group. Specific examples of the phosphoric acid monoester compound include 2-aminoethyl dihydrogen phosphate. Examples of the phosphoric acid amide monoester compound include creatine phosphate.

[0028] The phosphate group-containing compound may be a polymer. Examples of polymeric phosphate group-containing compounds include polymers in which one or two hydroxyl groups in the phosphoric acid are replaced by repeating units having carboxyl groups (for example, repeating units derived from (meth)acrylic acid). An example of a commercially available polymeric phosphate group-containing compound is "DEQUEST P9100" (manufactured by Italmatch).

[0029] In phosphonic acid group-containing compounds, the number of phosphonic groups is not particularly limited as long as it is one or more, for example, 1 to 4 groups. Examples of phosphonic acid group-containing compounds include bisphosphonic acid compounds. Specific examples of bisphosphonic acid compounds include compounds represented by the following formula (P1).

[0030]

[0031] In formula (P1), R Ｐ１ and R Ｐ２ Each of these independently represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 6 carbon atoms.

[0032] Specific examples of compounds represented by formula (P1) include etidronic acid and methylenebisphosphonic acid.

[0033] The phosphonic acid group-containing compound may be a polymer. Specific examples of polymers containing a phosphonic acid group include polymers containing repeating units that include a phosphonic acid group.

[0034] The phosphorus atom-containing acid may have a structure in which the oxo group (=O) in the phosphorus atom-containing oxo acid is replaced with a thio group (=S), for example, thiophosphate or thiophosphate monoester compounds. Examples of thiophosphate monoester compounds include thiophosphate monoalkyl ester compounds. The alkyl group is preferably having 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. The thiophosphate group-containing compound may also have substituents. Examples of substituents include unsubstituted amino groups and substituted amino groups.

[0035] Furthermore, the specific phosphorus atom-containing compound may be a salt of the phosphorus atom-containing acid (preferably a phosphorus atom-containing oxoacid) described above. The above-mentioned salt of the phosphorus atom-containing acid has a structure in which at least one proton of the acid group of the phosphorus atom-containing acid is replaced with another cation. Examples of the above-mentioned cation include alkali metal cations (preferably sodium ions, potassium ions, etc.). Specific examples of phosphorus atom-containing acid salts include sodium phosphate, sodium phosphonate, and disodium hydrogen phosphate.

[0036] The specific phosphorus atom-containing compound is preferably a compound having a pKa (25°C) in the pH range of 10.0 to 12.0, in order to exhibit good pH buffering capacity in a predetermined pH range and to achieve superior effects of the present invention. The specific phosphorus atom-containing compound may have multiple pKa values, and it is sufficient that at least one of the multiple pKa values ​​falls within the above numerical range. Phosphorus atom-containing oxoacids and their salts tend to satisfy the above characteristics.

[0037] As for specific phosphorus atom-containing compounds, it is preferable to include one or more selected from the group consisting of phosphoric acid and its salts, and phosphorous acid and its salts, in terms of superior handling properties, and more preferably to include one or more selected from the group consisting of phosphoric acid, phosphorous acid, and dihydrogen phosphate-aminoethyl.

[0038] The specific phosphorus atom-containing compound may be used alone or in combination of two or more types. The content of the specific phosphorus atom-containing compound is preferably 0.0001 to 5.0% by mass, more preferably 0.001 to 3.0% by mass, and even more preferably 0.001 to 1.0% by mass, based on the total mass of the drug solution. The content of the specific phosphorus atom-containing compound is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, even more preferably 10 to 40% by mass, and particularly preferably 10 to 30% by mass, based on the total mass of the drug solution excluding the solvent.

[0039] [Specific Compounds] This drug solution contains at least one specific compound selected from the group consisting of Compound 1 and Compound 2. Compound 1 is a compound having two or more groups selected from the group consisting of amino groups and hydroxyl groups, and Compound 2 is a compound having two or more groups selected from the group consisting of thiol groups and thioether groups. Note that the specific compounds are different from the specific phosphorus atom-containing compounds mentioned above. Compounds 1 and 2 will be described in detail below.

[0040] <First Compound> The first compound is a compound having two or more groups selected from the group consisting of amino groups and hydroxyl groups. The first compound includes compounds having two or more amino groups, compounds having one or more amino groups and one or more hydroxyl groups, and compounds having two or more hydroxyl groups. It is also preferable that the first compound is a compound having two or three groups selected from the group consisting of amino groups and hydroxyl groups. Among the first compounds, it is preferable that they be selected from the group consisting of compounds having two or more amino groups, and compounds having one or more amino groups and one or more hydroxyl groups.

[0041] In compounds having two or more amino groups, the number of amino groups should be two or more; for example, 2 to 5 is preferred, and 2 to 3 is more preferred. It is preferable that compounds having two or more amino groups do not contain hydroxyl groups. In compounds having one or more amino groups and one or more hydroxyl groups, the number of amino groups should be one or more; for example, 1 to 3 is preferred. The number of hydroxyl groups should be one or more; for example, 1 to 2 is preferred. In compounds having two or more hydroxyl groups, the number of hydroxyl groups should be two or more; for example, 2 to 5 is preferred, and 2 to 3 is more preferred. It is preferable that compounds having two or more hydroxyl groups do not contain amino groups.

[0042] The above amino group is a primary amino group (-NH ２ ), secondary amino group (-NHR or -NH-), tertiary amino group (-NR ２It includes (, -NR-, >N-). R represents a substituent. The first compound is preferably alkaline in aqueous solution (pH greater than 7.0 at 25°C). Among these, a compound in which the aqueous solution obtained by dissolving it at a ratio of 0.1 mol / L has a pH of 9.0 to 14.0 at 25°C is more preferred.

[0043] Specific examples of the first compound include aliphatic amines having two or more amino groups, amino alcohols (alkanolamines), alicyclic amines having two or more amino groups, and polyhydric alcohols.

[0044] <Amino Alcohols> Amino alcohols may have any of primary, secondary, or tertiary amino groups, but it is preferable that they have a tertiary amino group. Examples of amino alcohols include monoethanolamine (MEA), 3-amino-1-propanol, 1-amino-2-propanol, trishydroxymethylaminomethane (Tris), 2-amino-2-methyl-1-propanol (AMP), 2-dimethylamino-2-methyl-1-propanol (DMAMP), 2-amino-2-methyl-1,3-propanediol (AMPDO), 2-amino-2-ethyl-1,3-propanediol (AEPDO), 2-amino-1,3-propanediol (2-APDO), 3-amino-1,2-propanediol (3-APDO), 3-methylamino-1,2-propanediol (MAPDO), and 2-(methylamino)-2-methyl-1-propanediol (N Examples include -MAMP), 2-(aminoethoxy)ethanol (AEE), 2-(2-aminoethylamino)ethanol (AAE), diethanolamine (DEA), triethanolamine (TEA), N-methylethanolamine, N-butylethanolamine, N-cyclohexylethanolamine, 2-(ethylamino)ethanol, propylaminoethanol, diethylene glycolamine (DEGA), N,N'-bis(2-hydroxyethyl)ethylenediamine, 1,2-bis(2-aminoethoxy)ethane, N-methyldiethanolamine, N-tert-butyldiethanolamine, N-butyldiethanolamine, 1-piperidineethanol, and 1-(2-hydroxyethyl)piperazine. The number of carbon atoms in the above alkanolamines is preferably 2 to 12, more preferably 2 to 10, and even more preferably 2 to 6.

[0045] <Aliphatic amines having two or more amino groups> Aliphatic amines having two or more amino groups include alkylenediamines such as dimethylamine, diethylamine, ethylenediamine (EDA), 1,3-propanediamine (PDA), 1,2-propanediamine, 1,3-butanediamine, 1,4-butanediamine, 1,3-bis(dimethylamino)butane, and N-ethylethylenediamine (EEDA); polyalkyl polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), bis(aminopropyl)ethylenediamine (BAPEDA), tetraethylenepentamine, and N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA). The number of carbon atoms in the above aliphatic amines having two or more amino groups is preferably 2 to 12, and more preferably 2 to 10.

[0046] <Alicyclic amines having two or more amino groups> Examples of alicyclic amines having two or more amino groups include piperazine compounds. Piperazine compounds are compounds having a heterosix-membered ring (piperazine ring) in which the opposite >CH- group of the cyclohexane ring is replaced by a tertiary amino group (>N-). Examples of piperazine compounds include piperazine, 1-methylpiperazine, 2-methylpiperazine, 1-ethylpiperazine, 1-propylpiperazine, 1-butylpiperazine, 1,4-dimethylpiperazine, 2,5-dimethylpiperazine, 2,6-dimethylpiperazine, 1-phenylpiperazine, N-(2-aminoethyl)piperazine (AEP), 1,4-bis(2-aminoethyl)piperazine (BAEP), 1,4-bis(3-aminopropyl)piperazine (BAAPP), and 1,4-diazabicyclo[2.2.2]octane (DABCO). The number of carbon atoms in the alicyclic amine having two or more amino groups is preferably 2 to 12, and more preferably 2 to 10.

[0047] <Polyhydric Alcohols> Examples of polyhydric alcohols include aliphatic polyhydric alcohols. Examples of aliphatic polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. The number of carbon atoms in the above aliphatic polyhydric alcohols is preferably 2 to 12, more preferably 2 to 10, and even more preferably 2 to 6.

[0048] The first compound is preferably N-ethylethylenediamine (EEDA), 2-dimethylamino-2-methyl-1-propanol (DMAMP), propylene glycol (PG), or monoethanolamine (MEA).

[0049] <Second Compound> The second compound is a compound having two or more groups selected from the group consisting of thiol groups and thioether groups. It is also preferable that the second compound has two or three or more groups selected from the group consisting of thiol groups and thioether groups, and more preferably that it has two or three groups selected from the group consisting of thiol groups and thioether groups. The second compound includes compounds having two or more thiol groups, compounds having one or more thiol groups and one or more thioether groups, and compounds having two or more thioether groups. Among these, it is preferable that the second compound be selected from the group consisting of compounds having two or more thiol groups, and compounds having one or more thiol groups and one or more thioether groups. It is also preferable that the second compound further has a hydroxyl group.

[0050] In compounds having two or more thiol groups, the number of thiol groups may be two or more, for example, 2 to 5 is preferred, and 2 to 3 is more preferred. It is preferable that compounds having two or more thiol groups do not contain thioether groups. In compounds having one or more thiol groups and one or more thioether groups, the number of thiol groups may be one or more, for example, 1 to 3 is preferred. Similarly, the number of thioether groups may be one or more, for example, 1 to 3 is preferred. In compounds having two or more thioether groups, the number of thioether groups may be two or more, for example, 2 to 5 is preferred, and 2 to 3 is more preferred. It is preferable that compounds having two or more thioether groups do not contain thiol groups.

[0051] Specific examples of the second compound include, for example, methanedithiol, 1,2-ethanedithiol, 1,1-propanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 2,2-propanedithiol, 1,6-hexanedithiol, 1,2,3-propanetrithiol, 1,1-cyclohexanedithiol, 1,2-cyclohexanedithiol, 2,2-dimethylpropane-1,3-dithiol, and 3,4-dimethoxybutane-1,2 -Dithiol, 2-methylcyclohexane-2,3-dithiol, 1,1-bis(mercaptomethyl)cyclohexane, 2,3-dimercapto-1-propanol(2-mercaptoacetate), 2,3-dimercapto-1-propanol(3-mercaptopropionate), diethylene glycol bis(2-mercaptoacetate), diethylene glycol bis(3-mercaptopropionate), 1,2-dimercaptopropylmethyl ether 2,3-Dimercaptopropyl methyl ether, 2,2-Bis(mercaptomethyl)-1,3-propanedithiol, Bis(2-mercaptoethyl) ether, Ethylene glycol bis(2-mercaptoacetate), Ethylene glycol bis(3-mercaptopropionate), Trimethylolpropane bis(2-mercaptoacetate), Trimethylolpropane bis(3-mercaptopropionate), Pentaerythritol tetrapropyl (2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), tetrakis(mercaptomethyl)methane, glycerin di(mercaptoacetate), 3,4-dimercapto-2-propanol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3-butanediol (for example, dithioerythritol and dithiothreitol).Examples include aliphatic polythiol compounds such as pentaerythritol tris(3-mercaptopropionate), pentaerythritol bis(3-mercaptopropionate), pentaerythritol tris(thioglycolate), dipentaerythritol pentakis(3-mercaptopropionate), and hydroxymethyl-tris(mercaptoethylthiomethyl)methane (the carbon number of the above aliphatic polythiol compounds is preferably 2 to 12, more preferably 2 to 10, and even more preferably 2 to 6); and aliphatic polythioether compounds such as 2,2-bis(methylthio)methane (also known as 2,4-dithiapentane), 2,2-bis(methylthio)ethane, and 2,2-bis(methylthio)propane, and 3,6-dithia-1,8-octanediol (the carbon number of the above aliphatic polyether compounds is preferably 2 to 12, more preferably 2 to 10, and even more preferably 2 to 6). Furthermore, examples of compounds having one or more thiol groups and thioether groups include 2,2'-(ethylenebisthio)bis(ethanethiol). Among the second compounds, dithiothreitol is preferred.

[0052] One example of a preferred embodiment of a specific compound is one in which the molecular weight is 50 to 400.

[0053] The drug solution preferably contains both the first compound and the second compound, as this provides superior effects according to the present invention.

[0054] The specific compound may be used alone or in combination of two or more. The content of the specific compound is preferably 0.0001 to 10.0% by mass, more preferably 0.001 to 5.0% by mass, even more preferably 0.001 to 3.0% by mass, and particularly preferably 0.01 to 3.0% by mass, based on the total mass of the drug solution. Furthermore, the content of the specific compound is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and even more preferably 10 to 85% by mass, based on the total mass of the components in the drug solution excluding the solvent.

[0055] [Water] This chemical solution contains water. The type of water can be any water that does not adversely affect the semiconductor substrate, and distilled water, deionized (DI: De Ionize) 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 in the semiconductor substrate manufacturing process. The amount of water should be the remainder of the components that can be contained in this chemical solution. The amount of water is preferably 75.0% by mass or more, more preferably 85.0% by mass or more, even more preferably 90.0% by mass or more, and particularly preferably 95.0% by mass or more, based on the total mass of this chemical solution. The upper limit is preferably 99.999% by mass or less, more preferably 99.99% by mass or less, and even more preferably 99.95% by mass or less, in terms of achieving superior effects of the present invention.

[0056] [Other Ingredients] This chemical solution may contain ingredients other than the alkali source, specific phosphorus atom-containing compound, specific compound, and water mentioned above. Examples of other ingredients include corrosion inhibitors, organic acids, organic solvents, oxidizing agents, reducing agents, and fluorides.

[0057] <Corrosion Inhibitor> This chemical solution may contain a corrosion inhibitor. The corrosion inhibitor is a compound different from the specified phosphorus atom-containing compound and the specified compound described above. The corrosion inhibitor is not particularly limited as long as it is a compound that has the function of preventing corrosion of the exposed surface of a semiconductor substrate (especially copper-containing material), and examples include heterocyclic compounds. As heterocyclic compounds, nitrogen-containing heterocyclic compounds in which at least one of the heteroatoms constituting the heterocycle is a nitrogen atom are preferred. Examples of nitrogen-containing heterocyclic compounds include azole compounds, purine compounds, pyrrole compounds, pyridine compounds, pyrazine compounds, pyrimidine compounds, indole compounds, indidine compounds, indazole compounds, quinoline compounds, and oxazole compounds. Specifically, as a corrosion inhibitor, for example, the compounds described in paragraphs

[0046] to

[0050] of International Publication No. 2021 / 166571 can be referenced, and the contents of these are incorporated herein.

[0058] Among corrosion inhibitors, purine compounds are preferred because they exhibit excellent corrosion prevention effects on copper-containing materials by adsorbing onto them. Purine compounds are compounds having a purine skeleton (purines and purine derivatives).

[0059] Among the purine compounds, compounds selected from adenine, adenosine, guanine, hypoxanthine, xanthine, uric acid, and their derivatives are preferred, compounds selected from adenine, adenosine, guanine, xanthine, uric acid, and their derivatives are more preferred, and compounds selected from adenine, adenosine, guanine, xanthine, and their derivatives are even more preferred.

[0060] Examples of adenine or its derivatives include adenine, 1-methyladenine, 1-ethyladenine, 1-benzyladenine, 2-methyladenine, 2-chloroadenine, 2-fluoroadenine, 2-hydroxyadenine, 3-methyladenine, 8-aminoadenine, 9-methyladenine, 9-(2-hydroxyethyl)adenine, N-(2-hydroxyethyl)adenine, N-methyladenine, N,N-dimethyladenine, 2-azaadenine, 5-azaadenine, 8-azaadenine, and N ６ -Benzoyladenosine is an example. Examples of adenosine or its derivatives include adenosine, 2'-deoxyadenosine, and 2',3'-iso-propylidenadenosine. Examples of guanine or its derivatives include guanine, N-methylguanine, N-acetylguanine, O-cyclohexylmethylguanine, 7-(2-hydroxyethyl)guanine, N-(3-chlorophenyl)guanine, N-(3-ethylphenyl)guanine, 8-azaguanine, guanine oxime, 2'-deoxyguanosine, guanosine 5'-monophosphate disodium, and N ２Examples include -isobutyryl-2'-deoxyguanosine. Examples of hypoxanthine or its derivatives include hypoxanthine and 8-azahypoxanthine. Examples of xanthines or their derivatives include caffeine, theophylline, theophylline-7-acetic acid, 7-(2,3-dihydroxypropyl)theophylline, 7-(2-chloroethyl)theophylline, 8-chlorotheophylline, xanthine, 1-methylxanthine, 1-butyl-3,7-dimethylxanthine, 1-methyl-3,7-dipropylxanthine, 1,3-dipropyl-7-methylxanthine, 1,3-dipropyl-7-methyl-8-dicyclopropylmethylxanthine, 1,3-dibutyl-7-(2-oxopropyl)xanthine, 1,7-dimethylxanthine, 1,7-dipropyl-3-methylxanthine, 3-methylxanthine, 3,7-dimethyl-1-propylxanthine, 7-methylxanthine, 8-bromo-3-methylxanthine, 8-azaxanthine, 2-thioxanthine, and paraxanthine. Examples of uric acid or its derivatives include uric acid, 3-N-methyluric acid, 3-N-lauryluric acid, 7-N-butyluric acid, 1-N-ethyluric acid, 9-N-lauryluric acid, and 3,7-N-dimethyluric acid. Examples of xanthosine or its derivatives include xanthosine and 7-methylxanthosine. Examples of theobromine or its derivatives include theobromine and 1-(3-chloropropyl)theobromine.

[0061] Other purine compounds include, for example, purine, 6-mercaptopurine, 2-aminopurine, 2-amino-6-methoxypurine, 2-amino-6-iodopurine, 2-amino-6-chloropurine, 2,6-diaminopurine, 2,6-dichloropurine, 3,7-dihydro-7-methyl-1H-purine-2,6-dione, 6-aminopurine, 6-methoxypurine, 6-(dimethylamino)purine, 6-benzylaminopurine, 6-chloro-9-(tetrahydropyran-2-yl)purine, and 6-amino-8 Examples include phenyl-9H-purine, 6-ethylaminopurine, and 8-azapurine, isoguanine, emprophylline, eritadenine, nelarabine, vidarabine, acyclovir, trans-zeatin, entecavir, valacyclovir, abacavir, disodium inosinate, ganciclovir, β-nicotinamide adenine dinucleotide phosphate, clofarabine, kinetin, proxyphylline, 2',3'-dideoxyinosine, penciclovir, adefovir dipivoxil, and inosine.

[0062] The corrosion inhibitor may be used alone or in combination of two or more types. The content of the corrosion inhibitor is preferably 0.00001 to 0.1% by mass, more preferably 0.0001 to 0.08% by mass, and even more preferably 0.0001 to 0.05% by mass, based on the total mass of the chemical solution. Furthermore, the content of the corrosion inhibitor is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.5 to 2% by mass, based on the total mass of the components in the chemical solution excluding the solvent.

[0063] <Organic Acids> This chemical solution may contain organic acids. Note that organic acids are compounds different from the specified phosphorus atom-containing compounds and specified compounds mentioned above. Examples of organic acids include carboxylic acids such as aliphatic carboxylic acids and aromatic carboxylic acids. Organic acids may also be in the form of salts. Examples of the above salts include inorganic salts.

[0064] Examples of aliphatic carboxylic acids include succinic acid, tartaric acid, maleic acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, formic acid, citric acid, malic acid, glycolic acid, gluconic acid, heptonic acid, and lactic acid. Examples of aromatic carboxylic acids include phenyllactic acid, hydroxyphenyllactic acid, phenylsuccinic acid, phthalic acid, isophthalic acid, terephthalic acid, gallic acid, trimellitic acid, melitic acid, and cinnamic acid.

[0065] The organic acid may be used alone or in combination of two or more types. The content of the organic acid is preferably 0.00001 to 0.01% by mass, more preferably 0.0001 to 0.05% by mass, and even more preferably 0.001 to 0.05% by mass, based on the total mass of the chemical solution. Furthermore, the content of the organic acid is preferably 0.001 to 10.0% by mass, more preferably 0.01 to 5.0% by mass, and even more preferably 0.1 to 5.0% by mass, based on the total mass of the components in the chemical solution excluding the solvent.

[0066] <Organic solvents> Examples of organic solvents include known organic solvents, such as alcohol-based solvents, glycol-based solvents, glycol ether-based solvents, and ketone-based solvents. The organic solvent is preferably miscible with water in any ratio. Examples of organic solvents include compounds exemplified in paragraphs

[0135] to

[0140] of International Publication No. 2022 / 044893, the contents of which are incorporated herein by reference.

[0067] <Oxidizing Agent> This chemical solution may contain an oxidizing agent. The oxidizing agent is a compound different from the specified phosphorus atom-containing compound and specified compound mentioned above. Examples of oxidizing agents include peroxides (hydrogen peroxide, etc.), persulfides (e.g., monopersulfides and dipersulfides), percarbonates, their acids, and their salts. Examples of oxidizing agents include oxide halides (periodic acids such as iodic acid, metaperiodic acid, and orthoperiodic acid, and their salts), perboric acid, perborates, cerium compounds, and ferricyanides (potassium ferricyanide, etc.).

[0068] <Reducing Agent> This chemical solution may contain a reducing agent. The reducing agent is a compound different from the specified phosphorus atom-containing compound and the specified compound described above. Examples of reducing agents include catechol or its derivatives (e.g., methylcatechol, gallic acid, pyrogallol, ellagic acid, catechol-4-acetic acid, catechin, and isoflavone), ascorbic acid or its derivatives (e.g., isoascorbic acid, ascorbic acid sulfate, and ascorbic acid phosphate), and mercapto compounds (e.g., mercaptosuccinic acid, 1-thioglycerol, 2-mercaptoethanol, 3-mercapto-1-propanol, and thioglycolic acid). Compounds described in paragraphs

[0054] to

[0065] of International Publication No. 2019 / 187868 may also be used as reducing agents, and their contents are incorporated herein by reference.

[0069] Fluorides are compounds that serve as a source of fluorine-containing ions, and examples include compounds containing both fluorine-containing ions and cations. Examples of fluorine-containing ions include fluoride ions (F). － ), bifluoride ion (HF ２ － ), and fluoride-containing ions (e.g., MF ６ ｎ－ Examples of the above M include B, Al, Si, P, Ti, Zr, Nb, Sb, and Ta. Specific examples of fluorides include HF and NH. ４ F, H ２ SiF ６ H ２ TiF ６ H ２ ZrF ６ HPF ６ , and HBF ４ These are some examples.

[0070] [Physical Properties of the Solution] <pH> The pH of this solution is 11.5 or lower. The pH of this solution is preferably 8.0 to 11.5, more preferably 9.0 to 11.5, and even more preferably 10.0 to 11.5. The pH of this solution can be measured using a known pH meter in accordance with the method compliant with JIS Z8802-1984. The temperature for pH measurement is 25°C.

[0071] <Metal Content> The content (measured as ion concentration) of metals (e.g., Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, Ag) contained as impurities in this chemical solution is preferably 5 ppm by mass or less, and more preferably 1 ppm by mass or less, relative to the total mass of the chemical solution. Since it is anticipated that even higher purity of this chemical solution will be required in the manufacture of state-of-the-art semiconductor devices, it is even more preferable that the content of the above metals 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. A lower limit of 0 is preferred.

[0072] 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 material use during the manufacture of the chemical solution, or at a stage after the manufacture of the chemical solution. Other methods for reducing metal content include using containers that minimize the elution of impurities, as described later, for the raw materials or the manufactured chemical solution. Furthermore, lining the inner walls of pipes with fluororesin can be applied to prevent metal components from leaching from pipes during the manufacture of the chemical solution.

[0073] <Coarse Particles> This chemical solution may contain coarse particles, but it is preferable that the content be low. Coarse particles refer to particles whose diameter (particle size) is 1 μm or more when the shape of the particle is considered to be a sphere. Coarse particles contained in this chemical solution include particles such as dust, dirt, organic solids, and inorganic solids that are included as impurities in the raw materials, as well as particles such as dust, dirt, organic solids, and inorganic solids that are introduced as contaminants during the preparation of this chemical solution and that ultimately remain as particles in this chemical solution without dissolving.

[0074] The coarse particle content in this solution is preferably 100 or less, and more preferably 50 or less, of particles with a particle size of 1 μm or larger per 1 mL of the solution. The coarse particle content in this solution can be measured in the liquid phase using a commercially available measuring device that employs a light scattering type liquid particle measurement method with a laser as the light source. As for methods to remove coarse particles, for example, purification treatments such as filtering, which will be described later, can be used.

[0075] [Manufacturing Method] This drug solution can be manufactured by known methods. The manufacturing method of this drug solution is described in detail below.

[0076] [Preparation Process] This chemical solution can be manufactured, for example, by mixing the above components. One method for preparing this chemical solution is to sequentially add an alkali source, a phosphorus-containing acid, a specific compound, and any optional components as needed to a container containing purified water, and then stir to mix. When adding each component to the container, it may be added all at once or in multiple separate additions.

[0077] The stirring device and stirring method used for preparing this chemical solution may be any known device such as a stirrer or disperser. Examples of stirrs include industrial mixers, portable stirrers, mechanical stirrers, and magnetic stirrers. Examples of dispersers include industrial dispersers, homogenizers, ultrasonic dispersers, and bead mills.

[0078] The mixing of each component in the preparation process of this chemical solution, the purification process described later, and the storage of the manufactured chemical solution are preferably carried out at 40°C or below, and more preferably at 30°C or below. Furthermore, the lower limit is preferably 5°C or above, and more preferably 10°C or above. By preparing, processing, and / or storing this chemical solution within the above temperature range, its performance can be maintained stably for a long period of time.

[0079] <Purification> It is preferable to perform a purification treatment on one or more of the raw materials used to prepare this chemical solution beforehand. Examples of known purification methods include distillation, ion exchange, and filtration. The degree of purification is preferably such that the purity of the raw materials is 99% by mass or higher, and more preferably such that the purity of the stock solution is 99.9% by mass or higher. The upper limit is 99.9999% by mass or lower.

[0080] Methods of purification include, for example, passing the raw material through an ion exchange resin or RO membrane (Reverse Osmosis Membrane), reprecipitation, distillation of the raw material, and filtering. Multiple of the above purification methods may be combined as part of the purification process. For example, after primary purification by passing the raw material through an RO membrane, secondary purification may be performed by passing it through a purification apparatus consisting of a cation exchange resin, anion exchange resin, or mixed-bed ion exchange resin. Furthermore, the purification process may be performed multiple times.

[0081] The filters used for filtering are not particularly limited as long as they have been conventionally used for filtration purposes. For example, filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, polyallyl sulfone (PAS), and polyolefin resins such as polyethylene and polypropylene (PP) (including high-density or ultra-high molecular weight) are used. Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, and fluororesin filters are more preferred. By filtering raw materials using filters made of these materials, highly polar foreign substances that are likely to cause defects can be effectively removed.

[0082] <Container> This chemical solution (including the form of diluted chemical solution described later) can be filled into any container and stored, transported, and used, as long as corrosiveness or other issues do not pose a problem.

[0083] 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 containment area into each liquid is preferred for semiconductor applications. Examples of such containers include, but are not limited to, the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd. Furthermore, as a container, the containers exemplified in paragraphs

[0121] to

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

[0084] These containers are preferably cleaned inside before being filled with the chemical solution. The cleaning liquid is preferably one that has a reduced amount of metal impurities. The chemical solution may be bottled in containers such as gallon bottles or coated bottles after manufacturing for transport and storage.

[0085] To prevent changes in the components of this chemical 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. Furthermore, during transport, the temperature may be kept at room temperature, or controlled within a range of -20°C to 20°C to prevent deterioration.

[0086] <Cleanroom> It is preferable that all handling, processing, analysis, and measurement of this chemical solution, including its manufacture, opening and cleaning of containers, and filling, be carried out in a cleanroom. The cleanroom preferably meets the 14644-1 cleanroom standard. It is preferable that it meets any of ISO (International Organization for Standardization) Class 1, ISO Class 2, ISO Class 3, and ISO Class 4, more preferably ISO Class 1 or ISO Class 2, and even more preferably ISO Class 1.

[0087] [Dilution Step] The above-mentioned chemical solution may be used for cleaning semiconductor substrates as a diluted chemical solution (diluted chemical solution) after undergoing a dilution step in which it is diluted with a diluent such as water. The diluted chemical solution is also a form of the chemical solution of the present invention as long as it satisfies the requirements of the present invention.

[0088] It is preferable to perform a purification treatment on the diluent used in the dilution step beforehand. Furthermore, it is even more preferable to perform a purification treatment on the diluted chemical solution obtained in the dilution step. Examples of purification treatments include ion component reduction treatment using ion exchange resin or RO membrane, and foreign matter removal using filtering, as described above as purification treatments for the chemical solution, and it is preferable to perform either of these treatments.

[0089] The dilution ratio of the main chemical solution in the dilution step can be appropriately adjusted according to the type and content of each component and the semiconductor substrate to be cleaned. However, the ratio of the diluting chemical solution to the main chemical solution before dilution (dilution ratio) is preferably 10 to 10,000 times by mass ratio or volume ratio (volume ratio at 23°C), more preferably 20 to 3,000 times, even more preferably 50 to 1,000 times, and particularly preferably 75 to 150 times. Furthermore, for superior defect removal performance, the main chemical solution is preferably diluted with water (preferably ultrapure water).

[0090] The change in pH before and after dilution (the difference between the pH of the original solution and the pH of the diluted solution) is preferably 1.8 or less, more preferably 1.5 or less, and even more preferably 1.2 or less. The pH of the original solution and the pH of the diluted solution are preferably as described above.

[0091] The specific method for diluting this chemical solution should be carried out in accordance with the preparation process for this chemical solution described above. The stirring device and stirring method used in the dilution process should also be the known stirring device mentioned in the preparation process for this chemical solution described above.

[0092] [Intended Use] This chemical solution is used for cleaning semiconductor substrates, and is preferably used for cleaning semiconductor substrates that have undergone chemical mechanical polishing (CMP) treatment. Hereinafter, the object to be cleaned with this chemical solution will also be referred to as the "object to be cleaned." The objects to be cleaned with this chemical solution will be described in detail below.

[0093] [Object to be cleaned] As described above, the object to be cleaned is preferably a semiconductor substrate, and more preferably a semiconductor substrate containing metal. When the semiconductor substrate contains metal, the metal may be located anywhere on the semiconductor substrate, such as on the front and back surfaces, sides, and within grooves. Furthermore, when the semiconductor substrate contains metal, this includes not only cases where the metal is directly on the surface of the semiconductor substrate, but also cases where the metal is on the semiconductor substrate via other layers.

[0094] Examples of metals included in the above-mentioned metal-containing material include at least one metal M selected from the group consisting of copper (Cu), cobalt (Co), ruthenium (Ru), aluminum (Al), tungsten (W), titanium (Ti), tantalum (Ta), chromium (Cr), hafnium (Hf), osmium (Os), platinum (Pt), nickel (Ni), manganese (Mn), iron (Fe), zirconium (Zr), molybdenum (Mo), palladium (Pd), lanthanum (La), niobium (Nb), and iridium (Ir). At least one metal selected from the group consisting of copper, cobalt, ruthenium, molybdenum, and tungsten is preferred, at least one metal selected from the group consisting of copper and cobalt is more preferred, and copper is even more preferred. In other words, the semiconductor substrate to be cleaned preferably contains copper-containing material or cobalt-containing material, and more preferably contains copper-containing material.

[0095] The metal-containing material can be any substance containing metal atoms, for example, elemental metal M and alloys containing metal M. In particular, the object to be cleaned preferably contains a metal layer containing metal M as the metal-containing material, more preferably contains a metal layer containing copper, cobalt, ruthenium, molybdenum, or tungsten, even more preferably contains a metal layer containing copper or cobalt, and particularly preferably contains a metal layer containing copper.

[0096] Examples of copper-containing metal layers (copper-containing films) include wiring films made solely of metallic copper (copper wiring films) and wiring films made of alloys of metallic copper and other metals (copper alloy wiring films). Examples of copper alloy wiring films include wiring films made of alloys of Cu and at least one metal selected from the group consisting of Al, Ti, Cr, Mn, Ta, Nb, and 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), copper-niobium alloy wiring films (CuNb alloy wiring films), and copper-tungsten alloy wiring films (CuW alloy wiring films).

[0097] Examples of cobalt-containing metal layers (cobalt-containing films) include metal films made solely of metallic cobalt (cobalt metal films) and metal films made of alloys of metallic cobalt and other metals (cobalt alloy metal films). Examples of cobalt alloy metal films include metal films made of alloys of at least one metal selected from the group consisting of Ti, Cr, Fe, Ni, Mo, Pd, Ta, Nb, and W, and Co. 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), cobalt-niobium alloy wiring films (CoNb alloy wiring films), and cobalt-tungsten alloy metal films (CoW alloy metal films).

[0098] In addition to the metal wiring film described above, the object to be cleaned with this chemical solution may also include, for example, a wafer, an insulating film, and a barrier metal.

[0099] Examples of wafers constituting semiconductor substrates include silicon (Si) wafers, silicon carbide (SiC) wafers, and wafers made of silicon-based materials such as silicon-containing resin wafers (glass epoxy wafers), as well as gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, and indium phosphide (InP) wafers. Examples of silicon wafers include n-type silicon wafers doped with pentavalent atoms (e.g., phosphorus (P), arsenic (As), and antimony (Sb)), and p-type silicon wafers doped with trivalent atoms (e.g., boron (B) and gallium (Ga)). Examples of silicon in silicon wafers include amorphous silicon, single-crystal silicon, polycrystalline silicon, and polysilicon. Among these, wafers made of silicon-based materials such as silicon wafers, silicon carbide wafers, and silicon-containing resin wafers (glass epoxy wafers) are preferred.

[0100] Examples of insulating films include silicon oxide films (e.g., silicon dioxide (SiO2)). ２ ) film and tetraethyl orthosilicate (Si(OC ２ H ５ ) ４ ) film (TEOS film, etc.), silicon nitride film (for example, silicon nitride (Si ３ N ４ Examples include silicon dioxide (SOC) and silicon carbide nitride (SiNC), and low-dielectric constant (Low-k) films (for example, carbon-doped silicon oxide (SiOC) films, black diamond (BD) films, and silicon carbide (SiC) films), with low-dielectric constant (Low-k) films being preferred.

[0101] Examples of barrier metals include tantalum (Ta), tantalum nitride (TaN), titanium nitride (TiN), tungsten (W), tungsten alloys (such as tungsten-titanium (WTi) alloys and tungsten-cobalt (WCo) alloys), cobalt (Co), cobalt alloys, ruthenium (Ru), and ruthenium alloys.

[0102] There are no particular restrictions on the method for forming the above-mentioned insulating film, copper-containing film, and cobalt-containing film on a wafer constituting a semiconductor substrate, as long as it is a method commonly used in this field. For example, a method for forming the insulating film involves forming a silicon oxide film on a wafer constituting a semiconductor substrate by heat treatment in the presence of oxygen gas, and then forming a silicon nitride film by chemical vapor deposition (CVD) by introducing silane and ammonia gases. For example, a method for forming the copper-containing film and cobalt-containing film involves forming a circuit on a wafer having the above-mentioned insulating film using a known method such as resist, and then forming a metal layer by plating, physical vapor deposition (PVD), or CVD. The object to be cleaned may have a layer for forming the copper-containing film on the insulating layer.

[0103] <CMP Treatment> The object to be cleaned is preferably a semiconductor substrate that has undergone CMP treatment, more preferably a semiconductor substrate containing a metal that has undergone CMP treatment, and even more preferably a semiconductor substrate containing a copper that has undergone CMP treatment.

[0104] CMP treatment is a process that planarizes the surface of a substrate having a layer selected from, for example, a metal wiring film, a barrier metal, and an insulating film, by a combined chemical action using a polishing slurry containing abrasive particles and mechanical polishing. On the surface of an object to be cleaned after CMP treatment, residues such as abrasive particles used in the CMP treatment (e.g., silica and alumina), polished metal wiring films, and / or metal impurities derived from the barrier metal may remain. In addition, organic matter derived from the CMP composition used during the CMP treatment may remain as residue. Since these residues may, for example, short-circuit between wirings and degrade the electrical properties of the semiconductor substrate, semiconductor substrates that have undergone CMP treatment are subjected to a cleaning treatment to remove these residues from the surface. The composition of the present invention is preferably used as a cleaning solution in the cleaning treatment after CMP treatment as described above. Specific examples of objects to be cleaned after CMP treatment include, but are not limited to, the CMP-treated substrate described in the Journal of the Japan Society for Precision Engineering, Vol. 84, No. 3, 2018.

[0105] <Pad Cleaning Treatment> The object to be cleaned may undergo pad cleaning treatment after CMP treatment. Pad cleaning treatment is a treatment that uses a pad to reduce the residue present on the surface of the object to be cleaned. Specifically, the surface of the object to be cleaned, which has undergone CMP treatment, is brought into contact with the pad, and the object to be cleaned and the pad are slid relative to each other while a pad cleaning composition is supplied to the contact area. As a result, the residue on the surface of the object to be cleaned is removed by the frictional force of the pad and the chemical action of the pad cleaning composition.

[0106] The pads mentioned above are not particularly limited and can be appropriately selected depending on the type of object to be cleaned, the type of residue to be removed, and the equipment used. For example, polishing pads used in CMP (Computer Polishing) treatment may be used, as well as foamed polyurethane buff pads, nonwoven fabric buff pads, suede buff pads, and sponge buff pads. Note that pad cleaning treatment using pads includes a process called buff cleaning or buff polishing.

[0107] As the above-mentioned pad cleaning composition, known cleaning compositions can be used depending on the type of object to be cleaned and the type and amount of residue to be removed. Examples of components included in the pad cleaning composition include water-soluble polymers such as polyvinyl alcohol, dispersion media such as water, and acids such as nitric acid. Furthermore, the pad cleaning composition does not contain abrasive particles.

[0108] The apparatus and conditions used in the pad cleaning process can be appropriately selected from known apparatus and conditions depending on the type of object to be cleaned and the type and amount of residue to be removed. For example, the processing methods described in paragraphs

[0085] to

[0088] of International Publication No. 2017 / 169539 can be used, and these contents are incorporated herein.

[0109] Furthermore, as one embodiment of the pad cleaning process, it is also preferable to use this chemical solution as a pad cleaning composition to perform the pad cleaning process on the object to be cleaned. The chemical solution used for the pad cleaning process may be a diluted solution.

[0110] The pad cleaning process may be performed only once or two or more times. For example, the object to be cleaned may undergo pad cleaning using an abrasive pad and pad cleaning using a buffing pad after CMP treatment.

[0111] [Cleaning Method] The cleaning method for semiconductor substrates is not particularly limited as long as it includes a cleaning step of cleaning the semiconductor substrate using the chemical solution, and known methods performed on CMP-treated semiconductor substrates can be used. Examples of cleaning methods include bringing the semiconductor substrate into contact with the chemical solution. The above contact method is not particularly limited and includes, for example, immersing the semiconductor substrate in the chemical solution in a tank, spraying the chemical solution onto the semiconductor substrate, flowing the chemical solution onto the semiconductor substrate, and combinations thereof. The above methods can be appropriately selected depending on the purpose. Furthermore, the above methods may appropriately adopt the forms commonly used in this field. For example, scrubbing cleaning, in which a cleaning member such as a brush is physically brought into contact with the surface of the semiconductor substrate while supplying the chemical solution to remove residues, and spin (dropping) cleaning, in which the chemical solution is dropped onto the semiconductor substrate while rotating it, may be used. In the immersion method, it is preferable to apply ultrasonic treatment to the semiconductor substrate immersed in the chemical solution in order to further reduce impurities remaining on the surface of the semiconductor substrate. The above cleaning step may be performed once or two or more times. When washing two or more times, the same method may be repeated, or different methods may be combined. The chemical solution used in the above washing process may be a diluted solution.

[0112] The semiconductor substrate cleaning method may be either a single-wafer method or a batch method. The single-wafer method processes semiconductor substrates one at a time, while the batch method processes multiple semiconductor substrates simultaneously.

[0113] The temperature of the chemical solution in the washing process is not particularly limited, but in terms of defect removal, 10 to 60°C is preferred, 15 to 50°C is more preferred, and 15 to 40°C is even more preferred. The washing time in the washing process can be appropriately changed depending on the type and content of components that may be contained in the chemical solution, but 10 to 120 seconds is preferred, 20 to 90 seconds is more preferred, and 30 to 60 seconds is even more preferred. The supply amount (supply rate) of the chemical solution in the washing process is preferably 50 to 5000 mL / min, and 500 to 2000 mL / min is even more preferred.

[0114] In the cleaning process, mechanical stirring methods may be used to further enhance the cleaning performance of the chemical solution. Examples of mechanical stirring methods include circulating the chemical solution on a semiconductor substrate, flowing or spraying the chemical solution on a semiconductor substrate, and stirring the chemical solution with ultrasound or megasonic waves.

[0115] After the cleaning process, a step of bringing the semiconductor substrate into contact with a rinsing solution (hereinafter also referred to as the "rinsing process") may be performed. By performing the rinsing process, the semiconductor substrate obtained in the cleaning process can be washed with the rinsing solution, and residue can be efficiently removed. The rinsing process is preferably performed immediately after the cleaning process of the semiconductor substrate, and is a process of rinsing the semiconductor substrate with the rinsing solution. The rinsing process may be performed using the mechanical stirring method described above.

[0116] Examples of rinsing solutions include water (preferably deionized water), methanol, ethanol, isopropyl alcohol (IPA), N-methylpyrrolidinone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Alternatively, an aqueous rinsing solution with a pH greater than 8.0 (such as diluted aqueous ammonium hydroxide) may be used.

[0117] The method for bringing the rinse solution into contact with the semiconductor substrate can be similarly applied to the method described above for bringing the chemical solution into contact with the semiconductor substrate. The contact time between the semiconductor substrate and the rinse solution can be appropriately changed depending on the type and amount of each component contained in the chemical solution, as well as the target and purpose of use of the chemical solution. In practice, 10 to 120 seconds is preferred, 20 to 90 seconds is more preferred, and 30 to 60 seconds is even more preferred.

[0118] After the rinsing step described above, a drying step may be performed to dry the semiconductor substrate. Examples of drying methods include spin drying, passing a drying gas over the semiconductor substrate, heating the semiconductor substrate with heating means such as a hot plate and an infrared lamp, Marangoni drying, Rotagoni drying, IPA (isopropyl alcohol) drying, and any combination thereof.

[0119] [Method for Manufacturing Semiconductor Devices] The above cleaning method can be suitably applied to a method for manufacturing semiconductor devices. The above cleaning method may be carried out in combination before or after other processes performed on the substrate. The above cleaning method may be incorporated into other processes during the implementation of the above cleaning method, or the above cleaning method may be incorporated into other processes. Other processes include, for example, processes for forming structures such as metal wiring, gate structures, source structures, drain structures, insulating films, ferromagnetic layers, and non-magnetic layers (e.g., layer formation, etching, chemical mechanical polishing (CMP), and modification), resist formation processes, exposure processes, removal processes, heat treatment processes, cleaning processes, and inspection processes.

[0120] The above cleaning method may be performed at any stage of the backend process (BEOL), middle process (MOL), or frontend process (FEOL), and is preferably performed during the frontend process or middle process.

[0121] The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures 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 following examples.

[0122] In the following examples, the pH of the composition is 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 compositions in the examples and comparative examples, the handling of containers, preparation of the compositions, filling, storage, and analytical measurement are all carried out in a cleanroom meeting ISO Class 2 or lower standards.

[0123] [Raw Materials] The following compounds are used to manufacture the chemical solution. Note that all components used in the examples are classified as semiconductor grade or equivalent high-purity grade.

[0124] [Alkali Sources] ・ETMAH (Ethyltrimethylammonium Hydroxide) ・TEAH (Tetraethylammonium Hydroxide) ・THEMAH (Trihydroxyethylmethylammonium Hydroxide) ・TMAH (Tetramethylammonium Hydroxide) ・Choline ・KOH

[0125] [Acids containing phosphorus atoms] • Phosphorus • Phosphorous acid • 2-aminoethyl dihydrogen phosphate • Etidronic acid • DEQUEST P9100 (Italmatch) • Sodium polyphosphate • Trimethyl thiophosphate • Creatine phosphate

[0126] [Specific Compounds] <First Compound> ・DMAMP (2-dimethylamino-2-methyl-1-propanol) ・EEDA (N-ethylethylenediamine) ・PMDETA (N,N,N',N'',N''-pentamethyldiethylenetriamine) ・MEA (monoethanolamine) ・PG (propylene glycol)

[0127] <Second Compound> ・DTT (Dithiothreitol) ・DTE (Dithioerythritol) ・2,4-Dithiapentane

[0128] [Corrosion inhibitors] ・Adenine (classified as a purine compound) ・Xanthine (classified as a purine compound) [Comparative compounds] ・Sulfuric acid ・Cysteine

[0129] [Preparation and Evaluation of the Chemical Solution in Example 1] [Preparation of the Chemical Solution] The chemical solution in Example 1 was prepared by the following method. Ultrapure water, ETMAH (alkali source), phosphoric acid (phosphorus atom-containing acid), and DMAMP (first compound) were mixed and thoroughly stirred with a stirrer to prepare the chemical solution (concentrated composition).

[0130] [Evaluation of the chemical solution] A diluted solution was prepared by diluting the chemical solution (concentrated composition) of Example 1, manufactured using the method described above, with ultrapure water as the diluent at a dilution ratio of 100 times (by volume). The obtained diluted solution was used to evaluate its ability to inhibit copper corrosion and remove residue. The evaluation method is described below.

[0131] <Residue Removal Ease> A copper substrate cut to 2 cm x 2 cm was treated with a 1% by mass citric acid aqueous solution to remove the native oxide film from the copper substrate. The obtained copper substrate was immersed in an alkaline aqueous solution of 0.5% by mass benzotriazole (pH 9.5) for 30 minutes to deposit benzotriazole onto the surface of the copper substrate. Next, 50 mL of the chemical solution (diluted solution) from Example 1 was measured into a glass beaker, and the copper substrate with benzotriazole deposited on it was immersed for 3 minutes at room temperature with a stirring bar rotating at 400 rpm. Furthermore, the copper substrate after the above treatment was brought into contact with a 0.1 N hydrochloric acid aqueous solution to extract benzotriazole. The concentration of benzotriazole in the hydrochloric acid aqueous solution was measured by high-performance liquid chromatography (HPLC) and was taken as the concentration of benzotriazole after the above immersion treatment. In addition, the copper substrate with benzotriazole deposited on it was brought into contact with a 0.1 N hydrochloric acid aqueous solution without the above immersion treatment to extract benzotriazole. The concentration of benzotriazole in the above hydrochloric acid aqueous solution was measured by HPLC and taken as the concentration of benzotriazole before treatment. From the obtained concentrations, the removal rate was calculated using the following formula to evaluate the removal efficiency of the hydrophobic corrosion inhibitor (benzotriazole). The evaluation was carried out based on the following evaluation criteria. Removal rate of hydrophobic corrosion inhibitor (%) = {1 - (concentration of benzotriazole after treatment) / (concentration of benzotriazole before treatment)} × 100 (Evaluation criteria) A: 75% or more B: 60% or more, less than 75% C: 50% or more, less than 60% D: Less than 50%

[0132] [Corrosion Inhibition (Corrosion Protection)] A 2 x 2 cm Cu wafer was prepared and placed in a container filled with the chemical solution for each example or comparative example, and immersed at room temperature (25°C) for 30 minutes. The film thickness of the wafer before and after immersion was measured using a resistivity meter (VR300DE, manufactured by Kokusai Electric Semiconductor Service Co., Ltd.), and the etching rate (Å / min) was determined from the difference in film thickness before and after immersion. The corrosion inhibition of copper was evaluated according to the evaluation criteria below. The lower the etching rate, the better the corrosion inhibition of copper. It is preferable that the corrosion inhibition of copper be rated C or higher.

[0133] A: Less than 0.4 Å / min B: 0.4 Å / min or more, less than 0.8 Å / min C: 0.8 Å / min or more, less than 1.2 Å / min D: 1.2 Å / min or more

[0134] [Preparation and Evaluation of Drug Solutions in Examples 2-9, 13, 14, 16, 17, 19-22] [Preparation of Drug Solutions] Drug solutions (concentrated compositions) for Examples 2-9, 13, 14, 16, 17, 19-22 were prepared in accordance with the preparation method for the drug solution (concentrated composition) of Example 1.

[0135] [Evaluation of the chemical solution] For the chemical solutions (concentrated compositions) of Examples 2-9, 13, 14, 16, 17, and 19-22 produced by the method described above, dilutions are prepared by diluting them with ultrapure water at a dilution ratio of 100 times (by volume). Using each of the obtained dilutions, the corrosion inhibition properties of copper and the residue removal properties are evaluated in the same manner as in Example 1.

[0136] [Preparation and Evaluation of Drug Solutions in Examples 10-12, 15, and 18] [Preparation of Drug Solutions] Drug solutions (concentrated compositions) for Examples 10-12, 15, and 18 were prepared in accordance with the preparation method for the drug solution (concentrated composition) of Example 1.

[0137] [Evaluation of the chemical solution] For the chemical solutions (concentrated compositions) of Examples 10-12, 15, and 18, which were manufactured using the method described above, dilutions were prepared by diluting them with ultrapure water at a dilution ratio of 100 times (by volume). Using each of the obtained dilutions, the corrosion inhibition properties of copper and the residue removal properties were evaluated using the same procedure as in Example 1.

[0138] [Preparation and Evaluation of the Chemical Solutions of Comparative Examples 1 to 5] [Preparation of the Chemical Solutions] Each of the chemical solutions (concentrated compositions) of Comparative Examples 1 to 5 was prepared in accordance with the method for preparing the chemical solution (concentrated composition) of Example 1.

[0139] [Evaluation of the chemical solution] Diluted solutions were prepared by diluting the chemical solutions (concentrated compositions) of Comparative Examples 1 to 5, manufactured by the method described above, with ultrapure water as the diluent at a dilution ratio of 100 times (by volume). Using each of the obtained dilutions, the corrosion inhibition properties of copper and the residue removal properties were evaluated in the same manner as in Example 1.

[0140] [Preparation and Evaluation of the Drug Solution in Comparative Example 6] [Preparation of Drug Solution] Each drug solution (concentrated composition) of Comparative Example 6 was prepared in accordance with the preparation method of the drug solution (concentrated composition) of Example 1.

[0141] [Evaluation of the chemical solution] A diluted solution was prepared by diluting the chemical solution (concentrated composition) of Comparative Example 6, which was produced by the method described above, with ultrapure water as the diluent at a dilution ratio of 100 times (by volume). Using each of the obtained diluted solutions, the corrosion inhibition properties of copper and the residue removal properties were evaluated in the same manner as in Example 1.

[0142] [Results] Table 1 shows the composition and evaluation results of the chemical solutions (concentrated compositions) for each example and comparative example. As mentioned above, the evaluation uses a 100-fold (volume ratio) diluted solution of the chemical solution (concentrated composition) for each example and comparative example. In the table, the "Content (mass %)" column shows the content (mass %) of each component relative to the total mass of the chemical solution (concentrated composition). In the table, the value in the pH column shows the pH of the composition at 25°C as measured by the pH meter described above.

[0143]

[0144]

[0145] From the results in Table 1, it is clear that the chemical solutions of the examples, when used to clean semiconductor substrates containing copper that have undergone chemical mechanical polishing, exhibit excellent corrosion inhibition of copper and excellent removal of residues from the copper-containing material. Furthermore, from a comparison between Example 1 and Example 2, it was confirmed that the higher the pH of the chemical solution, the better the residue removal but the worse the corrosion protection against copper-containing material tends to be, while conversely, the lower the pH of the chemical solution, the better the corrosion protection against copper-containing material tends to be but the worse the residue removal. From the results of Examples 17 to 22, it was confirmed that when the chemical solution contains two or more specific compounds, the residue removal performance is even better. From the results of Examples 21 and 22, it was confirmed that when the chemical solution contains a corrosion inhibitor, the corrosion protection is even better.

[0146] On the other hand, it is clear that the desired effect cannot be obtained when using the comparative drug solution.

[0147] [Example 23] The chemical solution was prepared and evaluated using the same procedure as in Example 1, except that the phosphorus atom-containing compound was replaced from phosphoric acid to DEQUEST P9100 (Italmatch, phosphinopolycarboxylic acid copolymer). The results for pH, residue removal, and corrosion protection were the same as in Example 1.

[0148] [Example 24] The chemical solution was prepared and evaluated using the same procedure as in Example 1, except that the phosphorus atom-containing compound was replaced with sodium polyphosphate from phosphoric acid. The same results as in Example 1 were confirmed for pH, residue removal ability, and corrosion prevention ability.

[0149] [Example 25] The chemical solution was prepared and evaluated using the same procedure as in Example 1, except that the phosphorus atom-containing compound was replaced with trimethyl thiophosphate from phosphoric acid. The same results as in Example 1 were confirmed for pH, residue removal ability, and corrosion prevention ability.

[0150] [Example 26] The chemical solution was prepared and evaluated using the same procedure as in Example 1, except that the phosphorus atom-containing compound was replaced with creatine phosphate. The same results as in Example 1 were confirmed for pH, residue removal ability, and corrosion prevention ability.

Claims

1. A chemical solution comprising an alkali source, at least one specific phosphorus-containing compound selected from the group consisting of phosphorus-containing acids and their salts, at least one specific compound selected from the group consisting of a first compound and a second compound, and water, wherein the pH is 11.5 or less, the first compound has two or more groups selected from the group consisting of amino groups and hydroxyl groups, and the second compound has two or more groups selected from the group consisting of thiol groups and thioether groups.

2. The chemical solution according to claim 1, wherein the alkali source is a quaternary ammonium compound.

3. The drug solution according to claim 1 or 2, wherein the alkali source is an ethyltrimethylammonium compound.

4. The drug solution according to claim 1 or 2, wherein the specified phosphorus atom-containing compound comprises one or more selected from the group consisting of phosphorus atom-containing oxoacids and salts thereof.

5. The drug solution according to claim 1 or 2, wherein the specified phosphorus atom-containing compound comprises one or more selected from the group consisting of phosphoric acid and its salts.

6. The drug solution according to claim 1 or 2, wherein the specified phosphorus atom compound comprises one or more selected from the group consisting of phosphoric acid, phosphorous acid, and dihydrogen phosphate-aminoethyl.

7. The drug solution according to claim 1 or 2, wherein the first compound has two or three groups selected from the group consisting of amino groups and hydroxyl groups.

8. The drug solution according to claim 1 or 2, wherein the first compound comprises one or more compounds selected from compounds having two or more amino groups and compounds having one or more amino groups and one or more hydroxyl groups.

9. The drug solution according to claim 8, wherein the compound having one or more amino groups and hydroxyl groups, the number of hydroxyl groups is 1 to 2.

10. The drug solution according to claim 1 or 2, wherein the second compound has two or more groups selected from the group consisting of thiol groups and thioether groups.

11. The drug solution according to claim 1 or 2, wherein the second compound comprises one or more compounds selected from compounds having two or more thiol groups and compounds having one or more thiol groups and one or more thioether groups.

12. The drug solution according to claim 1 or 2, wherein the first compound comprises one or more selected from the group consisting of N-ethylethylenediamine, 2-dimethylamino-2-methyl-1-propanol, propylene glycol, and monoethanolamine.

13. The drug solution according to claim 1 or 2, wherein the second compound comprises dithiothreitol.

14. The chemical solution according to claim 1 or 2, further comprising a corrosion inhibitor.

15. The chemical solution according to claim 14, wherein the corrosion inhibitor contains a purine compound.

16. The chemical solution according to claim 14, wherein the corrosion inhibitor contains adenine.

17. The chemical solution according to claim 1 or 2, used for cleaning a semiconductor substrate containing copper that has been subjected to chemical mechanical polishing.

18. A method for cleaning a semiconductor substrate, comprising the step of bringing a semiconductor substrate containing copper, which has been subjected to chemical mechanical polishing, into contact with the chemical solution described in claim 1 or 2.

19. A method for manufacturing an electronic device, comprising the method for cleaning a semiconductor substrate as described in claim 18.

Images