Chemical solution, method for processing substrate, and method for manufacturing electronic device

Abstract

The present invention provides: a chemical solution which, when used to process a substrate that has been subjected to a chemical mechanical polishing treatment, leaves few residual anion components and few residues on the substrate; a method for processing a substrate using the chemical solution; and a method for manufacturing an electronic device. A chemical solution according to the present invention is to be used on a substrate that has been subjected to a chemical mechanical polishing treatment, the chemical solution comprising: an anionic polymer; one or more specific anions selected from the group consisting of SO4 2−, NO3 −, PO4 3−, F−, Cl−, and Br−; and water, the total amount of the specific anions being 1.0-1000 mass ppb relative to the total mass of the chemical solution.

Description

Chemical solutions, substrate processing methods, and electronic device manufacturing methods.

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

[0002] Semiconductor devices are manufactured by forming a resist film on a laminate having a metal film that serves as a wiring material, an etching stop layer, and an interlayer insulating layer on a substrate, and then performing a photolithography process. In the above photolithography process, a method of etching or removing foreign matter from the substrate surface using a processing solution that dissolves metals and / or organic materials is widely known.

[0003] Furthermore, in the manufacturing of semiconductor devices, chemical mechanical polishing (CMP) is sometimes performed to planarize the surface of a semiconductor substrate having metal wiring films, barrier metals, and insulating films using a polishing slurry containing polishing particles (e.g., silica and alumina). In CMP processing, metal components derived from the polishing particles used in the CMP process, the polished wiring metal films, and / or barrier metals tend to remain on the surface of the semiconductor substrate after polishing. For this reason, a process to remove these residues using a processing solution is generally carried out after CMP processing.

[0004] For example, Patent Document 1 discloses a residue cleaning solution that has high cleaning performance for residues generated during the manufacture of electronic circuits, also has a high corrosion protection effect on substrates such as insulating films, low dielectric films, and wiring, and produces little foam, described as "a residue cleaning solution comprising at least one solvent selected from amines and fluoride salts and an aqueous solution of a water-soluble polymer."

[0005] Japanese Patent Publication No. 2001-249465

[0006] When the present inventors applied the cleaning solution specifically disclosed in Patent Document 1 to a substrate that had undergone chemical and mechanical polishing, they found that the ability to remove both residual anion components and residues from the substrate was not entirely sufficient, and further improvements were needed.

[0007] Accordingly, an object of the present invention is to provide a chemical solution that, when treating a substrate subjected to chemical mechanical polishing, reduces residual anion components on the substrate and reduces residual residues on the substrate. Another object of the present invention is to provide a method for treating a substrate and a method for manufacturing an electronic device using the above chemical solution.

[0008] The inventor of the present invention has intensively studied to solve the above problems, and as a result, has completed the present invention. That is, the inventors have found that the above problems can be solved by the following constitution.

[0009] [1] A chemical solution used for a substrate that has been subjected to chemical mechanical polishing, comprising: an anionic polymer; SO ４ ２－ , NO ３ － , PO ４ ３－ , F － , Cl － , and Br － one or more specific anions selected from the group consisting of, and water, wherein a total content of the specific anions is 1.0 to 1000 mass ppb relative to the total mass of the chemical solution. [2] The chemical solution according to [1], wherein the anionic polymer is a polymer including a repeating unit having a carboxy group. [3] The chemical solution according to [1] or [2], wherein the anionic polymer is polyacrylic acid. [4] The chemical solution according to any one of [1] to [3], comprising at least SO ４ ２－ as the specific anion. [5] The chemical solution according to any one of [1] to [4], wherein a content of the anionic polymer is 0.0002 to 5 mass% relative to the total mass of the chemical solution. [6] The chemical solution according to any one of [1] to [5], wherein a total content of the specific anions is 1.0 to 500 mass ppb relative to the total mass of the chemical solution. [7] The chemical solution according to any one of [1] to [6], wherein a total content of the specific anions is 1.0 to 50 mass ppb relative to the total mass of the chemical solution. [8] SO ４ ２－ and NO ３ － and contains at least NO３ － SO486 ４ ２－ The mass ratio of the content is 1.0 to 1.0 × 10 ３ The drug solution described in any one of [1] to [7]. [9] As the specified anion, SO ４ ２－ NO ３ － , and PO ４ ３－ It includes at least one of the following, SO ４ ２－ NO ３ － , and PO ４ ３－ The drug solution according to any one of [1] to [8], wherein the total content of is 60 ppb by mass or less relative to the total mass of the drug solution.

[10] The mass ratio of the content of the anionic polymer to the total content of the specified anions is 1.0 × 10 ３ ~1.0 x 10 ５ A chemical solution according to any one of [1] to [9].

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

[10] that substantially contains neither an oxidizing agent nor abrasive particles.

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

[11] that further comprises at least one of a quaternary ammonium compound and a polycarboxylic acid.

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

[12] having a pH of 10.0 to 13.0.

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

[12] having a pH of 5.5 to 6.5.

[15] A chemical solution according to any one of [1] to

[14] used as a cleaning solution for the above substrate.

[16] A chemical solution according to any one of [1] to

[15] , wherein the above substrate is a substrate used for hybrid bonding and subjected to chemical mechanical polishing treatment.

[17] A method for processing a substrate, comprising the step of bringing a substrate that has been subjected to chemical and mechanical polishing treatment into contact with any one of [1] to

[16] .

[18] The method for processing a substrate according to

[17] , wherein the substrate includes a copper region.

[19] A method for manufacturing an electronic device, comprising the method for processing a substrate according to

[17] .

[0010] According to the present invention, when a substrate that has undergone chemical mechanical polishing is treated, a chemical solution can be provided that leaves little residual anion component and little residue on the substrate. Furthermore, according to the present invention, a method for treating a substrate using the above chemical solution and a method for manufacturing an electronic device can be provided.

[0011] 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.

[0012] 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.

[0013] In the notation of groups (atomic groups) in this specification, notations that do not specify substitution or unsubstituted include both substituted and unsubstituted groups, to the extent that they do not impair the effects of the present invention. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups. This is also true for each compound. Unless otherwise specified, monovalent substituents are preferred. The bonding direction of divalent groups as expressed in this specification 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". Examples of halogen atoms in this specification include fluorine, chlorine, bromine, and iodine atoms.

[0014] In this specification, if there are two or more components, 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 ) means "ppt" is "parts-per-trillion (10－１２ It means ")".

[0015] [Chemical Solution] The chemical solution of the present invention will be described in detail below. A chemical solution used on a substrate that has undergone chemical mechanical polishing treatment, comprising an anionic polymer and SO ４ ２－ NO ３ － , PO ４ ３－ F － , Cl － , and Br － The solution contains one or more specific anions selected from the group consisting of the following, water, and the total content of the specific anions is 1.0 to 1000 ppb by mass relative to the total mass of the chemical solution.

[0016] The reason why the chemical solution 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. The chemical solution of the present invention, by containing an anionic polymer, can effectively remove residues from the substrate. Furthermore, as described above, in the chemical solution of the present invention, the content of the specific anion is below a predetermined amount, thereby reducing the amount of specific anion residue on the substrate. Moreover, the content of the specific anion is above a predetermined amount, which allows the charge of the substrate surface and residue after chemical mechanical polishing to be changed to an appropriate range, resulting in superior residue removal. Therefore, it is presumed that the chemical solution of the present invention, having the above configuration (particularly, the content of the specific anion being within the predetermined range), can effectively reduce both residual anionic components and residues on the substrate. Hereinafter, when a substrate that has been chemically and mechanically polished using the chemical solution of the present invention is treated, if at least one of the following is better—that there is less residual anionic content on the substrate and that there is less residue on the substrate—this is also referred to as "the effect of the present invention is superior."

[0017] [Anionic Polymer] The chemical solution of the present invention contains an anionic polymer. An anionic polymer is a polymer containing a functional group that exhibits anionic properties when dissolved in water, such as a carboxyl group (hereinafter also referred to as "anionic functional group"). Preferably, the above anionic polymer is a polymer containing repeating units having anionic functional groups (hereinafter also referred to as "repeating unit A"). As will be described in detail later, the anionic polymer may contain repeating units other than repeating unit A, but it is preferable that the polymer consists only of repeating unit A. The anionic polymer may contain two or more types of repeating unit A.

[0018] <Repeating Unit A> The number of anionic functional groups in repeating unit A is not particularly limited, but is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 to 3. The anionic functional groups in repeating unit A are not particularly limited, but examples include acid groups. The acid groups may be monovalent or divalent. Specific examples of the above acid groups include carboxyl groups, sulfonic acid groups, phosphonic acid groups, phosphinic acid groups, and phenolic hydroxyl groups. The above acid groups may also be salts, and examples of salts include ammonium salts, potassium salts, sodium salts, and lithium salts.

[0019] In terms of superior effects of the present invention, the anionic polymer preferably contains repeating units A having an acid group selected from a carboxyl group, a sulfonic acid group, a phosphonic acid group, and a phosphinic acid group, more preferably contains at least one of a repeating unit having a carboxyl group and a repeating unit having a sulfonic acid group, and even more preferably contains a repeating unit having a carboxyl group.

[0020] Examples of repeating units A include repeating units derived from compounds having anionic functional groups and ethylenically unsaturated groups. Specific examples of anionic functional groups are as described above. Ethylenelycol-unsaturated groups are functional groups having ethylenically unsaturated bonds. Examples of ethylenically unsaturated groups include vinyl groups and acrylamide groups (CH4). ２ =CH-CONH-), methacrylamide group (CH２ = CCH ３ -CONH-), aromatic vinyl group, acryloyloxy group (CH ２ =CH-COO-), methacryloyloxy group (CH ２ = CCH ３ Examples include -COO-), maleimide groups, and vinyl ether groups. Among the ethylenically unsaturated groups, vinyl groups, acrylamide groups, acryloyloxy groups, methacryloyloxy groups, or aromatic vinyl groups are preferred. Styryl groups are preferred as aromatic vinyl groups.

[0021] The repeating unit A is preferably the repeating unit represented by formula (a).

[0022]

[0023] In formula (a), R ａ１ , R ａ２ and R ａ３ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an acid group. ａ This represents a single bond or a (k+1) valence linking group. ａ If it is a single bond, k represents 1. A represents an acid group. k represents an integer from 1 to 4. If there are multiple acid groups in formula (a), the multiple acid groups may be the same or different.

[0024] R ａ１ , R ａ２ and R ａ３ Preferably, the group is a hydrogen atom, a halogen atom (fluorine atom, chlorine atom, bromine atom, or iodine atom), a methyl group, an ethyl group, or a carboxyl group, with hydrogen atoms, methyl groups, or carboxyl groups being more preferred. ａ１ , R ａ２ and R ａ３ However, it is preferable that all of them are hydrogen atoms. Also, R ａ１ , R ａ２ and R ａ３ It is also preferable that one of them represents a hydrogen atom, a methyl group, or a carboxyl group, and the remaining two both represent hydrogen atoms.

[0025] L ａThe (k+1) valency linking group represented by is not particularly limited as long as it has a valency corresponding to the number of A, but for example, a di- to pentavalent aliphatic hydrocarbon group which may have substituents, a di- to pentavalent aromatic hydrocarbon group which may have substituents, a di- to pentavalent aromatic heterocyclic group which may have substituents, -O-, -CO-, -SO ２ -, -NR Ｌ Examples include -, -N<, and groups formed by combinations thereof. Ｌ k represents a hydrogen atom or a monovalent aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched, or cyclic. k is preferably 1, in which case L ａ The divalent linking groups represented by include divalent aliphatic hydrocarbon groups, divalent aromatic hydrocarbon groups, divalent aromatic heterocyclic groups, -O-, -CO-, and -SO ２ -, -NR Ｌ Examples include groups formed by combining these, and among them, single bonds, -CO-O-, -CO-NH-, alkylene groups having 1 to 5 carbon atoms, phenylene groups, and groups formed by combining these are preferred.

[0026] Examples of acid groups represented by A include carboxyl groups, sulfonic acid groups, phosphonic acid groups, phosphinic acid groups, and phenolic hydroxyl groups, with carboxyl groups or sulfonic acid groups being preferred, and carboxyl groups being more preferred. k represents an integer from 1 to 4, with 1 or 2 being preferred.

[0027] Examples of repeating units A include repeating units derived from compounds selected from the group consisting of acrylic acid, maleic acid, 2-acrylamido-2-methylpropanesulfonic acid, itaconic acid, vinylacetic acid, allylacetic acid, fumaric acid, p-styrenesulfonic acid, vinylsulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, vinylphosphonic acid, vinyl phosphoric acid, and N-vinylacetamide.

[0028] The content of repeating unit A is not particularly limited, but is preferably 50 to 100 mol%, more preferably 75 to 100 mol%, and even more preferably 90 to 100 mol% relative to the total repeating units of the anionic polymer.

[0029] <Repeating Unit B> The above anionic polymer may contain repeating unit B, which is different from repeating unit A. Repeating unit B is not particularly limited, but examples include repeating units derived from compounds selected from the group consisting of aromatic vinyl compounds, alkyl (meth)acrylate compounds which may have hydroxyl groups, unsaturated alcohol compounds, aliphatic conjugated diene compounds, vinyl cyanide compounds, and amide compounds having polymerizable double bonds.

[0030] Examples of the above aromatic vinyl compounds include styrene, α-methylstyrene, vinyltoluene, and p-methylstyrene.

[0031] The content of repeating unit B is not particularly limited, but is preferably 0.1 to 50 mol%, more preferably 1 to 25 mol%, and even more preferably 1 to 15 mol% relative to the total repeating units of the anionic polymer.

[0032] Examples of anionic polymers include poly(meth)acrylic acid, poly(acrylic acid-maleic acid), 2-acrylamide-2-methylpropanesulfonic acid-acrylic acid copolymer, poly(phosphino-carboxylic acid), polyitaconic acid, polymaleic acid, polyfumaric acid, polyaspartic acid, polyglutamic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, poly(2-acrylamide-2-methyl-1-propanesulfonic acid), polyphosphate, polyvinyl phosphate, polyvinylphosphonic acid, poly(N-vinylacetamide), and styrene sulfonic acid-acrylic acid-vinylphosphonic acid copolymer, with polyacrylic acid being preferred.

[0033] The weight-average molecular weight of the anionic polymer is preferably 500 to 50,000, more preferably 1,000 to 30,000, even more preferably 2,000 to 20,000, and particularly preferably 4,000 to 10,000.

[0034] The anionic polymer may be used alone or in combination of two or more types. The content of the anionic polymer is preferably 0.00001 to 5% by mass, more preferably 0.0002 to 5% by mass, even more preferably 0.0002 to 1% by mass, and particularly preferably 0.001 to 0.1% by mass, based on the total mass of the drug solution.

[0035] [Specific Anion] The chemical solution of the present invention contains the above specific anion (SO ４ ２－ NO ３ － , PO ４ ３－ F － , Cl － , and Br － The solution contains one or more selected from the group consisting of the above, and the total content of the specific anion is 1.0 to 1000 ppb by mass relative to the total mass of the chemical solution. The specific anion may be intentionally added, inevitably contained in the raw materials of the chemical solution, or inevitably contained during the manufacture, storage, and / or transport of the chemical solution. For example, the content can be adjusted to the above-described range by methods such as removing the specific anion from the chemical solution and / or the raw materials of the chemical solution, adding a component containing the specific anion (a source of the specific anion), or a combination thereof. Specifically, when preparing the chemical solution, and / or immediately before processing the substrate that has undergone the above-described chemical mechanical polishing treatment, a raw material mainly composed of a compound containing the specific anion may be added to the aqueous solution containing the anionic polymer, or a raw material that inevitably contains a trace amount of the specific anion may be used in the preparation of the chemical solution. Among these, the method of adding a source of the specific anion to a mixture of raw materials from which the specific anion has been removed is preferred because it allows for easy control of the composition.

[0036] As a method for removing the above specific anions, a known method may be appropriately selected according to the form of the specific anions in the chemical solution and / or the raw material of the chemical solution. Examples thereof include purification treatments such as ion removal treatment and filtration treatment described later, and anion exchange treatment is preferable. Further, any compound containing the specific anion can be used as the supply source of the above specific anion, and examples thereof include ionic compounds that dissociate in a chemical solution to generate the specific anion. Among these, inorganic acids having the specific anion as a conjugate base are preferable, and more specifically, sulfuric acid (H ２ SO ４ ), nitric acid (HNO ３ ), phosphoric acid (H ３ PO ４ ), hydrofluoric acid (HF), hydrochloric acid (HCl), and hydrobromic acid (HBr).

[0037] The method for quantifying the specific anions in the chemical solution is not particularly limited, and for example, measurement is performed by ion chromatography. Further, when the composition of the raw material is known, the content of the specific anions may be calculated and obtained. In the present specification, unless otherwise specified, for ion chromatography analysis, Dionex ICS-6000 manufactured by Thermo Scientific is used as a measuring device, and UTAC-LP2 manufactured by Thermo Scientific, which is a concentration column, is used as an ion chromatography column. When the concentration column as described above is used, only the specific anion component can be retained and water as the matrix can be removed, so quantification is possible even when the content of the specific anion is an extremely small amount on the ppt order.

[0038] The chemical solution may contain two or more types of the specific anions. In particular, from the viewpoint of reducing residues, the chemical solution preferably contains three or more types of the specific anions, and more preferably contains four or more types of the specific anions. From the viewpoint that the effect of the present invention is more excellent, the chemical solution contains SO ４ ２－ , NO ３ － , and PO ４ ３－ preferably contains at least one of SO ４ ２－ and NO３ － it is more preferable to include at least one of, and it is further preferable to include at least SO ４ ２－ . The total content of the specific anions is not particularly limited as long as it is 1.0 to 1000 mass ppb based on the total mass of the above chemical solution. From the viewpoint that residual anionic components on the substrate are further reduced, the content is preferably 500 mass ppb or less, more preferably 100 mass ppb or less, still more preferably 50 mass ppb or less, and particularly preferably 5 mass ppb or less. Among these, when the chemical solution contains SO ４ ２－ , NO ３ － , and PO ４ ３－ and contains at least one of them, the total content of SO ４ ２－ , NO ３ － , and PO ４ ３－ is preferably 60 mass ppb or less based on the total mass of the above chemical solution, and from the viewpoint that a better balance is achieved between the amount of residual anionic components on the substrate and the residue removal performance on the substrate, the content is more preferably 1 to 60 mass ppb. Further, when the chemical solution contains SO ４ ２－ and NO ３ － and contains at least these, the mass ratio of the content of SO ３ － to the content of NO ４ ２－ is 1.0×10 －２ to 1.0×10 ３ , which is preferable, and more preferably 1.0 to 1.0×10 ３ .

[0039] In addition, the mass ratio of the content of the anionic polymer to the total content of the specific anions is not particularly limited, and for example, it is preferably 1.0×10 ２ to 1.0×10 ５ , and from the viewpoint that a better balance is achieved between the amount of residual anionic components on the substrate and the residue removal performance on the substrate, the mass ratio of the content of the anionic polymer to the total content of the specific anions is 1.0×10 ３ to 1.0×10５ It is more preferable that it be 1.0 × 10 ３ ~1.0 x 10 ４ It is even more preferable that this be the case.

[0040] [Water] The chemical solution of the present invention contains water. The water may contain unavoidable trace amounts of mixed components. Among these, purified water such as distilled water, ion-exchanged water, or ultrapure water is preferred, and ultrapure water used in semiconductor manufacturing is more preferred. The water content in the chemical solution is not particularly limited, but is preferably 60.000% by mass or more, more preferably 80.000% by mass or more, and even more preferably 98.000% by mass or more. Furthermore, there is no particular upper limit, but is preferably 99.9999% by mass or less, and more preferably 99.999% by mass or less.

[0041] [Additives] In terms of achieving superior effects of the present invention, the chemical solution of the present invention preferably contains at least one additive selected from heterocyclic compounds, organic acids, inorganic acids, organic bases, inorganic bases, stabilizers, surfactants, polymers, polyhydroxy compounds with a molecular weight of 500 or more, and organic solvents. It is more preferable to contain at least one additive selected from organic acids, organic bases (especially water-soluble amines), and heterocyclic compounds, and even more preferable to contain at least one of organic acids and organic bases (especially water-soluble amines). Additives may be used alone or in combination of two or more, but in terms of achieving superior effects of the present invention, it is preferable to contain three or more additives, and even more preferable to contain four or more additives. There is no particular upper limit to the number of types of additives contained in the chemical solution of the present invention, but it is often five or fewer. The content of additives is preferably 0.0001 to 1.0% by mass, more preferably 0.0005 to 0.1% by mass, and even more preferably 0.001 to 0.05% by mass, based on the total mass of the chemical solution. Furthermore, it is preferable that the chemical solution of the present invention substantially contains no oxidizing agent. It is also preferable that the chemical solution of the present invention substantially contains neither an oxidizing agent nor abrasive particles. "Substantially containing no oxidizing agent" means that the amount of oxidizing agent in the chemical solution is less than 0.001% by mass of the total mass of the chemical solution. Additives will be described below.

[0042] <Heterocyclic Compounds> Heterocyclic compounds are compounds that have a heterocyclic structure within their molecule. It is preferable that heterocyclic compounds function as corrosion inhibitors for metals contained in the substrate described later. Examples of heteroatoms contained in the heterocycle include nitrogen atoms, sulfur atoms, oxygen atoms, and phosphorus atoms. The heterocyclic compound may be monocyclic or polycyclic. The heterocyclic compound may be either aliphatic heterocyclic compounds or aromatic heterocyclic compounds, but aromatic heterocyclic compounds are preferred. Examples of heterocyclic compounds include azole compounds.

[0043] Azole compounds are compounds having an aromatic heterogeneous five-membered ring containing nitrogen atoms. The number of nitrogen atoms in the aromatic heterogeneous five-membered ring of an azole compound is preferably 1 to 4, and more preferably 1 to 3. Azole compounds may have substituents on the aromatic heterogeneous five-membered ring. Examples of such substituents include hydroxyl groups, carboxyl groups, mercapto groups, amino groups, C1 to C4 alkyl groups which may contain amino groups, and 2-imidazolyl groups.

[0044] Examples of azole compounds include pyrrole compounds in which one of the atoms constituting the azole ring is a nitrogen atom, imidazole compounds and 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 tetrazole compounds in which four of the atoms constituting the azole ring are nitrogen atoms.

[0045] 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 their derivatives, with benzimidazole being preferred. Examples of pyrazole compounds include 2,4-dimethylthiazole, 3,5-dimethylpyrazole, benzothiazole, 2-mercaptobenzothiazole, and their derivatives, with 3,5-dimethylpyrazole being preferred. Examples of thiazole compounds include 2,4-dimethylthiazole, benzothiazole, 2-mercaptobenzothiazole, and their derivatives. Examples of triazole compounds include 1,2,4-triazole, 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, 5-methylbenzotriazole, 2,2'-{[(5-methyl-1H-benzotriazole-1-yl)methyl]imino}diethanol, and their derivatives. Examples of tetrazole compounds include 1H-tetrazole (1,2,3,4-tetrazole), 5-methyltetrazole, 5-aminotetrazole, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, 1-(2-dimethylaminoethyl)-5-mercaptotetrazole, and their derivatives, with 5-aminotetrazole being preferred.

[0046] Examples of heterocyclic compounds other than azole compounds include aromatic heterocyclic compounds such as purines, indoles, quinolines, pyridines, pyrimidines, carbazoles, and triazines, as well as aliphatic heterocyclic compounds such as methylisothiazolinone, piperazines, piperidines, imidazolines, and their derivatives.

[0047] <Organic Acids> Organic acids are compounds having an acidic group. Note that the anionic polymers mentioned above are not included in organic acids. Organic acids may function as pH adjusters in chemical solutions. Examples of acidic groups in organic acids include carboxyl groups, phosphonic acid groups, and sulfo groups, with carboxyl groups or phosphonic acid groups being preferred. Examples of organic acids include carboxylic acid compounds and phosphonic acid compounds, with phosphonic acid compounds being preferred because they contain fewer residual anionic components.

[0048] Examples of carboxylic acid compounds include aminopolycarboxylic acid-based organic acids, amino acid-based organic acids, and aliphatic carboxylic acid-based organic acids, with aliphatic carboxylic acid-based organic acids being preferred. The carboxylic acid compound may also be a polycarboxylic acid. A polycarboxylic acid is a compound having two or more carboxyl groups in its molecule. The carboxylic acid compound may also have a hydroxyl group in addition to the carboxyl group. In other words, the carboxylic acid compound may be a hydroxycarboxylic acid compound. Furthermore, the carboxylic acid compound may also be an aromatic carboxylic acid-based organic acid such as trimellitic acid.

[0049] Examples of aliphatic carboxylic acid organic acids include maleic acid, citric acid, tartaric acid, malic acid, succinic acid, malonic acid, oxalic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, gluconic acid, heptonic acid, sorbic acid, glycolic acid, and lactic acid. Examples of aminopolycarboxylic acid organic acids include 1,4-butanediaminetetraacetic acid (BDTA), diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetrapropionic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, 1,3-propanediamine-N,N,N',N'-tetraacetic acid, ethylenediaminetetraacetic acid (EDTA), and trans-1,2-diaminocycloacetic acid. Examples include xantetraacetic acid, 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). Examples of amino acid-based organic acids include cysteine, glycine, serine, α-alanine (2-aminopropionic acid), β-alanine (3-aminopropionic acid), lysine, leucine, isoleucine, cystine, ethionine, threonine, tryptophan, tyrosine, valine, histidine, histidine derivatives, asparagine, aspartic acid, glutamine, glutamic acid, arginine, proline, methionine, phenylalanine, compounds described in paragraphs

[0021] to

[0023] of Japanese Patent Publication No. 2016-086094, and salts thereof. When the organic acid is an amino acid-based organic acid, it is preferable that it is an amino acid containing a thiol group, such as cysteine, in that it has fewer residual anionic components.

[0050] Examples of phosphonic acid compounds include 1-hydroxyethylidene-1,1'-diphosphonic acid (ethidronic acid, HEDP), ethylidenediphosphonic acid, 1-hydroxypropylidene-1,1'-diphosphonic acid, 1-hydroxybutylidene-1,1'-diphosphonic acid, ethylaminobis(methylenephosphonic acid), dodecylaminobis(methylenephosphonic acid), and nitrilotris(methylenephosphonic acid) (NTPO).

[0051] <Stabilizer> It is preferable that the drug solution contains a stabilizer in order to improve the stability of the drug solution. The stabilizer preferably contains at least one compound selected from the group consisting of phenolic compounds, quinone compounds, free radical compounds, amine compounds and phosphine compounds, with phenolic compounds being more preferable.

[0052] <Surfactants> Surfactants are not particularly limited as long as they are compounds having both a hydrophilic group and a hydrophobic group (lipophilic group) in one molecule. Surfactants often have at least one hydrophobic group selected from the group consisting of aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof. The total number of carbon atoms in the surfactant is preferably 16 to 100.

[0053] Examples of surfactants include nonionic surfactants and anionic surfactants. Examples of nonionic surfactants include ester-type nonionic surfactants, ether-type nonionic surfactants, and ester-ether-type nonionic surfactants, with ether-type nonionic surfactants being preferred. Examples of nonionic surfactants include compounds exemplified in paragraph

[0126] of International Publication No. 2022 / 044893, the contents of which are incorporated herein by reference. Examples of anionic surfactants include compounds exemplified in paragraphs

[0118] and

[0122] of International Publication No. 2022 / 044893, the contents of which are incorporated herein by reference.

[0054] <Polymers> As polymers, for example, water-soluble polymers described in paragraphs

[0043] to

[0047] of Japanese Patent Application Publication No. 2016-171294 can be used, and the contents of these are incorporated herein.

[0055] <Polyhydroxy Compounds with Molecular Weight of 500 or More> Polyhydroxy compounds with a molecular weight of 500 or more are compounds different from the above compounds that may be contained in the drug solution. The above polyhydroxy compounds are organic compounds having two or more (e.g., 2 to 200) alcoholic hydroxyl groups in one molecule. The molecular weight (weight-average molecular weight if there is a molecular weight distribution) of the above polyhydroxy compounds is 500 or more, preferably 500 to 100,000, and more preferably 500 to 3,000. As the above polyhydroxy compounds, compounds exemplified in paragraphs

[0101] and

[0102] of International Publication No. 2022 / 014287 may also be incorporated herein by reference, and the contents of these are incorporated herein by reference.

[0056] <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

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

[0057] <Inorganic Acids> Examples of inorganic acids include sulfuric acid, acetic acid, nitric acid, phosphoric acid, and hydrofluoric acid. Inorganic acids may also function as pH adjusters in chemical solutions.

[0058] <Organic Bases> Examples of organic bases include quaternary ammonium compounds and water-soluble amines, with quaternary ammonium compounds being preferred. The organic base may also function as a pH adjuster in the chemical solution.

[0059] The quaternary ammonium compound is preferably a compound having a quaternary ammonium cation in which four hydrocarbon groups (preferably alkyl groups) are substituted on the nitrogen atom. Alternatively, the quaternary ammonium compound may be a compound having a quaternary ammonium cation in which the nitrogen atom in the pyridine ring is bonded to a substituent (such as an alkyl group or a hydrocarbon group such as an aryl group), such as alkylpyridinium. Examples of quaternary ammonium compounds include quaternary ammonium hydroxides, quaternary ammonium acetates, and quaternary ammonium carbonates. The compound represented by formula (A) is preferred as the quaternary ammonium compound.

[0060]

[0061] In formula (A), Y － The symbol represents an anion. Examples of anions include acid anions such as carboxylate ions, phosphate ions, phosphonate ions, and nitrate ions, as well as hydroxide ions, with hydroxide ions being preferred.

[0062] In formula (A), R Ａ１ ~R Ａ４ Each of these independently represents a hydrocarbon group which may have substituents. Ａ１ ~R Ａ４The total number of carbon atoms in the group represented by is not particularly limited, but for example, it is 4 or more, preferably 4 to 30, more preferably 4 to 25, even more preferably 4 to 15, and particularly preferably 5 to 10. If the hydrocarbon group has substituents, the number of substituents is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. Examples of substituents that the hydrocarbon group may have include halogen atoms such as fluorine, chlorine, and bromine atoms; alkyl groups; alkoxy groups; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups; acyl groups such as acetyl, propionyl, and benzoyl groups; cyano groups; nitro groups; thiol groups; and dioxylanyl groups. The number of carbon atoms in the hydrocarbon group is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the hydrocarbon group include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, and groups combining these. The alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl groups, with methyl, ethyl, n-propyl, or isopropyl groups being preferred, and methyl or ethyl groups being more preferred. The alkenyl group and alkynyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkenyl group and alkynyl group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 5. Examples of the alkenyl group and alkynyl group include vinyl, allyl, ethynyl, and propargyl groups. The aryl group may be monocyclic or polycyclic. The number of carbon atoms in the above aryl group is preferably 6 to 20, more preferably 6 to 10, and even more preferably 6 to 8. Examples of the above aryl group include benzyl, phenyl, naphthyl, anthryl, phenanthryl, indenyl, acenaphthenyl, fluorenyl, and pyrenyl groups, with benzyl or phenyl being preferred and phenyl being more preferred.

[0063] Preferred water-soluble amines include monoethanolamine, aminomethylpropanol, and alkanolamines such as tris(hydroxymethyl)aminomethane.

[0064] <Inorganic Bases> Examples of inorganic bases include aqueous ammonia, alkali metal hydroxides, and alkaline earth metal hydroxides. Inorganic bases may also function as pH adjusters in the chemical solution.

[0065] <Abrasive Particles> Preferably, the chemical solution contains substantially no abrasive particles. Abrasive particles refer to particles contained in a polishing solution used for polishing semiconductor substrates, and whose average primary particle diameter is 5 nm or more. Examples of the above abrasive particles include inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. Substantially containing no abrasive particles means that the abrasive particle content is less than 0.1% by mass of the total mass of the chemical solution, preferably 0.01% by mass or less, and more preferably 0.001% by mass or less. There is no particular lower limit, and it is 0% by mass. The abrasive particle content can be measured using a commercially available measuring device in a light scattering liquid particle measurement method using a laser as the light source. Furthermore, the average primary particle diameter of abrasive particles is determined by measuring the particle diameters (equivalent circle diameters) of 1000 primary particles arbitrarily selected from images acquired using a JEOL Ltd. transmission electron microscope TEM2010 (pressure voltage 200kV), and then taking the arithmetic mean of these measurements. The equivalent circle diameter is the diameter of a circle assumed to have the same projection area as the observed particle. Methods for removing abrasive particles from the chemical solution include purification processes such as filtering.

[0066] [Physical Properties of the Chemical Solution] <pH> The pH of the chemical solution of the present invention is not particularly limited, but it is preferably basic (greater than 7.0). In particular, a pH of 8.0 or higher is preferred, 10.0 or higher is more preferred, 11.0 or higher is even more preferred, and 12.0 or higher is especially preferred in terms of reducing residue on the substrate. As an upper limit, a pH of 14.0 or lower is preferred, and 13.0 or lower is more preferred. However, the chemical solution of the present invention may be acidic, and in particular when treating a substrate having a tungsten surface with the chemical solution of the present invention, it is preferable that it be acidic in terms of reducing residue. If the chemical solution is acidic, the pH is preferably 5.0 or higher, and more preferably 5.5 or higher. As an upper limit, a pH of 6.5 or lower is preferred, and more preferably 6.0 or lower. The pH of the chemical solution can be measured using a known pH meter in accordance with the method in accordance with JIS Z8802-1984. The temperature for pH measurement is 25°C.

[0067] <Metal Content> The content (measured as ion concentration) of metals (for example, metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the chemical solution is preferably 5 ppm by mass or less, and more preferably 1 ppm by mass or less, relative to the total mass of the chemical solution. Since even higher purity chemical solutions are expected to be required in the manufacture of state-of-the-art semiconductor devices, it is even more preferable that the content of the above metals be lower than 1 ppm by mass, that is, 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.

[0068] 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. Additionally, lining the inner walls of pipes with fluororesin can be applied to prevent metal components from leaching out during the manufacture of the chemical solution.

[0069] <Coarse Particles> The 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 particle shape is considered to be spherical. Coarse particles contained in the 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 the chemical solution, and which ultimately remain as particles in the chemical solution without dissolving.

[0070] The coarse particle content in the drug 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 drug solution. The lower limit is preferably 0 or more, and more preferably 0.01 or more, per 1 mL of drug solution. The coarse particle content present in the drug 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 of removing coarse particles, for example, purification treatments such as filtering, which will be described later, can be used.

[0071] [Manufacturing Method] The above-mentioned chemical solution can be manufactured by known methods. For example, it can be manufactured by mixing the above-mentioned components to a predetermined concentration. The order in which the components are mixed is not particularly limited. The raw materials and / or mixtures thereof of the chemical solution may be subjected to a purification process to remove specific anions and / or impurities. In particular, it is preferable to manufacture the chemical solution using anionic polymers, water, and additives obtained by purifying the purified material containing each component. Furthermore, when manufacturing the chemical solution of the present invention, it is preferable to manufacture the chemical solution by purifying the purified material containing each component as described above to reduce specific anions, and then adding a predetermined amount of a source of specific anions to the mixture obtained by mixing the resulting raw materials. The above purification process preferably includes at least the ion exchange process and filtration process described later. It is preferable that the purified material has a low impurity content. Examples of commercially available products of such purified material include, for example, commercially available products called "high-purity grade products".

[0072] Known methods can be used for purifying the product to be purified, including, for example, ion removal treatment, filtration treatment, and distillation treatment, and multiple treatments may be combined. Furthermore, each purification treatment may be performed multiple times. For example, after performing primary purification by distillation of the product to be purified, secondary purification may be performed by passing the obtained product through an ion exchange resin and / or filter. Alternatively, after performing primary purification by passing the product to be purified through an ion exchange resin and / or filter, secondary purification may be performed by distillation of the obtained product.

[0073] <Ion Removal Treatment> Ion removal treatment is a treatment in which the substance to be purified is subjected to ion exchange or ion adsorption by a chelating group. The components removed by ion removal treatment are not particularly limited, but examples include specific anions and metal ions. There are no particular restrictions on the method of ion exchange treatment, and known methods can be used. In ion exchange treatment, the substance to be purified may be passed through the same ion exchange resin multiple times, or it may be passed through different ion exchange resins. For example, one method is to bring the ion exchange resin and the substance to be purified into contact, and another is to pass the substance to be purified through a packed section filled with ion exchange resin. Furthermore, ion removal treatment may be used in combination with the filtration treatment described later. For example, a column packed with ion exchange resin may be incorporated into the above-mentioned circulating filtration device, and the substance may be passed continuously through the packed section of ion exchange resin and the filter.

[0074] Examples of ion exchange resins include anion exchange resins and cation exchange resins. When using both cation exchange resins and anion exchange resins, the material may pass through a filled section filled with a mixed resin containing both resins, or it may pass through multiple filled sections filled with each resin separately. As the anion exchange resin, known anion exchange resins can be used, for example, gel-type anion exchange resins. Specifically, examples of anion exchange resins include strongly basic anion exchange resins having quaternary ammonium groups and weakly basic anion exchange resins having amino groups. Commercially available anion exchange resins can be used, such as Amberlite IRA-400J, Amberlite IRA-410J, Amberlite IRA-900J, Amberlite IRA-67, ORLITE DS-2, ORLITE DS-5, ORLITE DS-6 (manufactured by Organo), Duolite A113LF, Duolite A116, Duolite A-375LF (manufactured by Sumika Chemtex), and DIAION SA12A, DIAION SA10A, DIAION SA10AOH, DIAION SA20A, DIAION WA10 (manufactured by Mitsubishi Chemical Corporation). Anion exchange resins described in Japanese Patent Publication No. 2009-155208 can also be used.

[0075] As the cation exchange resin, known cation exchange resins can be used, such as gel-type anion exchange resins. Specifically, examples of cation exchange resins include sulfonic acid-type cation exchange resins and carboxylic acid-type cation exchange resins. Commercially available cation exchange resins can be used, such as Amberlite IR-124, Amberlite IR-120B, Amberlite IR-200CT, ORLITE DS-1, ORLITE DS-4 (all manufactured by Organo Corporation), Duolite C20J, Duolite C20LF, Duolite C255LFH, Duolite C-433LF (all manufactured by Sumika Chemtex), DIAION SK-110, DIAION SK1B, DIAION SK1BH (all manufactured by Mitsubishi Chemical Corporation), and Purolite S957, Purolite S985 (both manufactured by Purolite Corporation).

[0076] The ion adsorption treatment using chelating groups is not particularly limited, and known methods can be used. The ion removal treatment may involve passing the material to be purified through the same chelating resin multiple times, or passing the material to be purified through different chelating resins. For example, one method is to pass the material to be purified through a packed section filled with a chelating resin having chelating groups. Examples of chelating resins include resins with chelating groups or chelating ability, such as amidooxime groups, thiourea groups, thiouronium groups, iminodiacetic acid, amide phosphoric acid, phosphonic acid, amino phosphoric acid, aminocarboxylic acid, N-methylglucamine, alkylamino groups, pyridine rings, cyclic cyanines, phthalocyanine rings, and cyclic ethers.

[0077] <Filtration Treatment> The filtration treatment method is not particularly limited, and known methods can be used. Among these, filtering using a filter to filter the material to be purified is preferred. The components removed by the filtration treatment are not particularly limited, but examples include metal particles and coarse particles. The filter used for filtering is not particularly limited, and known filters can be used. Examples of the material of the filter include fluororesins such as PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxyalkane), polyamide resins such as 6-nylon and 6,6-nylon, polyolefin resins such as polyethylene and polypropylene (including high density and ultra-high molecular weight), diatomaceous earth, and glass. Among these, PTFE, polyamide resins, UPE (ultra-high density polyethylene), HDPE (high density polyethylene), and HDPP (ultra-high density polypropylene) are preferred. By using filters made of these materials, highly polar foreign matter that is likely to cause particle defects and metal impurities can be removed more effectively.

[0078] The critical surface tension of the filter is preferably 70 to 95 mN / m, and more preferably 75 to 85 mN / m. The manufacturer's nominal value can be used as the critical surface tension value. By using a filter with a critical surface tension within the above range, highly polar foreign matter that is likely to cause particle defects, as well as metallic impurities, can be removed more effectively.

[0079] The pore size of the filter is preferably 0.1 nm to 1.0 μm, more preferably 0.5 nm to 0.1 μm, and even more preferably 1.0 to 50.0 nm. By setting the pore size of the filter within the above range, fine foreign matter contained in the purified material can be effectively removed while suppressing clogging of the filter.

[0080] The filter may be surface-treated. The surface treatment method is not particularly limited, and known methods can be used. Examples of surface treatments include chemical modification, plasma treatment, hydrophobic treatment, coating, gas treatment, and sintering, with chemical modification or plasma treatment being preferred. As for the chemical modification, a treatment to introduce ion exchange groups is preferred. That is, the filter may be an ion exchange filter. Examples of ion exchange groups include sulfonic acid groups, carboxyl groups, and phosphate groups as cation exchange groups, and quaternary ammonium groups as anion exchange groups. There are no particular limitations on the method of introducing ion exchange groups into the filter, but for example, a method of grafting is used in which a compound containing ion exchange groups and polymerizable groups is reacted with a polymer contained in the filter.

[0081] Filtering may be a multi-stage filtration process in which the material to be purified is passed through two or more filters, each differing in at least one characteristic selected from the group consisting of filter material, pore size, and pore structure. Alternatively, the material to be purified may be passed through the same filter multiple times, or through multiple filters of the same type. Among these, a circulating filtration process is preferred, in which the material is passed through filters multiple times using a filtration device that combines multiple filters and a return path. The number of cycles in the circulating filtration process is not particularly limited and can be appropriately selected according to the desired purity and impurities, but 2 to 100 cycles are preferred, 20 to 80 cycles are more preferred, and 30 to 70 cycles are even more preferred. The number of filters to be combined is not particularly limited, but 1 to 10 are preferred, and 2 to 5 are more preferred. When filtering is performed by combining different filters, it is preferable that the pore size of the filter that comes into contact with the liquid first is the same as or larger than the pore size of the filter that comes into contact with the liquid later. The pore size can be determined by referring to the nominal value of the filter manufacturer.

[0082] Commercially available filters can be selected from a variety of filters offered by companies such as Nippon Pall Co., Ltd., Advantech Toyo Co., Ltd., Nippon Integris Co., Ltd., or Kitz Microfilter Corporation.

[0083] The filtering temperature is preferably 25°C or lower, more preferably 23°C or lower, and even more preferably 20°C or lower. The lower limit is preferably 0°C or higher, more preferably 5°C or higher, and even more preferably 10°C or higher. By keeping the filtering temperature within the above range, particulate foreign matter and impurities dissolved in the chemical solution can precipitate and be efficiently removed.

[0084] <Distillation Treatment> There are no particular restrictions on the method of distillation treatment, and known methods can be used. For example, a method using a distillation column can be used. In the distillation treatment, the material to be purified may be passed through the same distillation column multiple times, or it may be passed through different distillation columns. There are no particular restrictions on the wetted parts of the distillation column, but it is preferable that they be made of corrosion-resistant material. When the material to be purified is passed through different distillation columns, for example, a method can be used in which the material to be purified is passed through a distillation column to perform a crude distillation treatment to remove low-boiling point acids, etc., and then passed through a different distillation column to perform a rectification treatment to remove acid components and other organic compounds, etc. In this case, a tray-type distillation column can be used as the distillation column for the crude distillation treatment, and a distillation column including at least one of a tray-type distillation column and a vacuum tray-type distillation column can be used as the distillation column for the rectification treatment. When using a tray-type distillation column, the number of theoretical stages is preferably 50 or more, and more preferably 100 or more. There is no particular upper limit, but it is often 200 or less.

[0085] <Containers> The chemical solution (including the form of the diluted chemical solution described later) can be filled into any container for storage, transport, and use, provided that corrosiveness or other issues do not pose a problem. As for the container, a container that is clean inside and suppresses the elution of impurities from the inner wall of the container's containment section 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 containers, 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.

[0086] These containers are preferably cleaned inside before being filled with the chemical solution. The liquid used for cleaning 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. To prevent changes in the components of the chemical solution during storage, the inside of the container may be replaced with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. A gas with a particularly low water content is preferred. Furthermore, during transport and storage, the temperature may be at room temperature, or it may be controlled to a range of -20°C to 20°C to prevent deterioration.

[0087] <Cleanroom> It is preferable that all handling, processing, analysis, and measurement of chemicals, including the manufacture of chemicals, opening and cleaning of containers, and filling of chemicals, be carried out in a cleanroom. It is preferable that the cleanroom 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.

[0088] [Dilution Step] The above chemical solution may undergo a dilution step using a diluent such as water, and then be used for processing the semiconductor substrate as a diluted chemical solution (diluted chemical solution). 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.

[0089] 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 for the above-mentioned chemical solution include ion component reduction treatment using ion exchange resin or RO membrane, and foreign matter removal using filtering, and it is preferable to perform either of these treatments.

[0090] The dilution ratio of the chemical solution in the dilution process can be appropriately adjusted according to the type and content of each component, as well as the workpiece to be treated (semiconductor substrate). However, the ratio of the diluted chemical solution to the undiluted chemical solution (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, and even more preferably 50 to 1,000 times. Furthermore, for superior defect removal performance, the chemical solution is preferably diluted with water (preferably ultrapure water).

[0091] The change in pH before and after dilution (the difference between the pH of the undiluted solution and the pH of the diluted solution) is preferably 3.0 or less, more preferably 2.8 or less, and even more preferably 2.5 or less. The pH of the undiluted solution and the pH of the diluted solution are preferably as described above.

[0092] The specific method for the dilution step of diluting the chemical solution may be carried out in accordance with the chemical solution preparation step described above. The stirring device and stirring method used in the dilution step may also be carried out using the known stirring device mentioned in the chemical solution preparation step described above.

[0093] [Applications] As described above, the chemical solution of the present invention is used on substrates that have undergone chemical mechanical polishing (CMP treatment), but it is preferable to use it as a cleaning solution for the above substrates. For example, the chemical solution of the present invention can be suitably used as a cleaning solution for substrates that have been used in hybrid bonding and subjected to CMP treatment. The substrates to which the chemical solution of the present invention is applicable will be described in detail below.

[0094] [Substrate] Examples of substrates include semiconductor substrates containing metal. The metal may be located on the front and back surfaces, sides, or within grooves of the semiconductor substrate. Furthermore, when a 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 present on the semiconductor substrate via other layers. Examples of the metal 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), with Cu being preferred. In other words, it is preferable for the semiconductor substrate to include a copper region.

[0095] The metal preferably exists as a metal layer containing the metal. Examples of the form of the metal contained in the metal layer include elemental metal M and alloys containing metal M. In particular, the semiconductor substrate preferably has a metal layer containing metal M, and more preferably has a metal layer containing Cu.

[0096] Examples of Cu-containing metal layers (Cu-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. Furthermore, the shape of the Cu-containing metal layer is not particularly limited, and may, for example, be Cu filling contact holes and via holes. In other words, the Cu-containing metal layer may form embedded copper regions. The semiconductor substrate used in the above hybrid bonding is often a laminate having copper-containing via holes at least on its surface. The chemical solution of the present invention is preferable because it can clean the copper surface while suppressing recession on the copper surface, even in copper regions with small surface areas as described above.

[0097] Examples of metal layers containing Co (Co-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 semiconductor substrate may also have, for example, a semiconductor 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, silicon nitride (SiNC), and silicon carbide (SiNC), as well as low-dielectric constant (Low-k) films (e.g., carbon-doped silicon oxide (SiOC) films, black diamond (BD) films, and silicon carbide (SiC) films). In particular, semiconductor substrates used in the above hybrid bonding often have an insulating surface containing a dielectric selected from silicon dioxide, silicon nitride, silicon carbonitride, and tetraethyl orthosilicate.

[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 semiconductor substrate may also have a layer for forming the copper-containing film or cobalt-containing film on the insulating layer.

[0103] <CMP Treatment> The chemical solution is used on a substrate that has undergone CMP treatment (more preferably a semiconductor substrate containing metal).

[0104] CMP (Compound Polishing) is a process that planarizes the surface of a substrate having layers 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. The surface of a CMP-treated workpiece (e.g., a semiconductor substrate) may have residues such as abrasive particles used in the CMP process (e.g., silica and alumina), polished metal wiring films, and / or metal impurities derived from the barrier metal. Organic matter derived from the CMP treatment solution used during the CMP process may also remain as residue. Because these residues may, for example, short-circuit the wiring and degrade the electrical properties of the semiconductor substrate, CMP-treated substrates are subjected to a cleaning process to remove these residues from the surface.

[0105] <Substrate with pad cleaning treatment> The surface of the substrate may be subjected to pad cleaning treatment after CMP treatment. Pad cleaning treatment is a process that uses a pad to reduce residue present on the surface of the workpiece (e.g., semiconductor substrate). Specifically, the surface of the workpiece that has undergone CMP treatment is brought into contact with the pad, and the workpiece 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 workpiece is removed by the frictional force of the pad and the chemical action of the pad cleaning composition.

[0106] The pad described above is not particularly limited and can be appropriately selected depending on the type of workpiece (e.g., semiconductor substrate), the type of residue to be removed, and the equipment used. The pad may be an abrasive pad used in CMP processing, or it may be a foamed polyurethane buff pad, a nonwoven fabric buff pad, a suede buff pad, or a sponge buff pad. The pad cleaning process using the pad includes a process called buff cleaning or buff polishing. Furthermore, as the pad cleaning composition, known cleaning compositions can be used depending on the type of workpiece (e.g., semiconductor substrate) and the type and amount of residue to be removed. Examples of components in the pad cleaning composition include water-soluble polymers such as polyvinyl alcohol, dispersion media such as water, and acids such as nitric acid. The pad cleaning composition does not contain abrasive particles.

[0107] The apparatus and conditions used in the pad cleaning process can be appropriately selected from known apparatus and conditions depending on the type of material to be processed and the type and amount of residue to be removed. For example, the processing method described in paragraphs

[0085] to

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

[0108] Furthermore, as one embodiment of the pad cleaning process, it is also preferable to perform the pad cleaning process on the workpiece (e.g., a semiconductor substrate) using the chemical solution of the present invention as a pad cleaning composition. The pad cleaning process may be performed only once or two or more times. For example, after CMP treatment, a pad cleaning process using a polishing pad and a pad cleaning process using a buffing pad may be performed.

[0109] [Method for processing substrates] An example of a method for processing substrates using the chemical solution of the present invention is a processing method that includes a step (processing step) of bringing a substrate that has undergone CMP processing into contact with the chemical solution of the present invention.

[0110] As a processing method for treating a substrate using a chemical solution, known processing methods performed on CMP-treated workpieces (e.g., semiconductor substrates) can be used. Examples of substrate processing methods include contacting the substrate with the chemical solution. The contact method is not particularly limited and includes, for example, immersing the substrate in a chemical solution in a tank, spraying the chemical solution onto the substrate, flowing the chemical solution onto the substrate, and combinations thereof. The above method can be appropriately selected depending on the purpose. Furthermore, the above method may appropriately adopt a style commonly used in this field. For example, scrubbing, which removes residue by physically contacting the substrate surface with a cleaning member such as a brush while supplying the chemical solution, and spin (dropping) methods, which drop the chemical solution while rotating the substrate, may be used. In the immersion method, ultrasonic treatment is preferable to the substrate immersed in the chemical solution in order to further reduce impurities remaining on the substrate surface. The above processing may be performed once or two or more times. When cleaning two or more times, the same method may be repeated, or different methods may be combined.

[0111] The substrate processing 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.

[0112] The temperature of the chemical solution in the processing step 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.

[0113] The pH of the chemical solution and the pH of the diluted chemical solution are preferably in the preferred form of the pH described above.

[0114] The processing time in the processing step can be appropriately changed depending on the type and amount 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.

[0115] The supply rate (feed rate) of the chemical solution in the processing step is preferably 50 to 5000 mL / min, and more preferably 500 to 2000 mL / min.

[0116] In the processing step, 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.

[0117] After the processing step, a step of bringing the semiconductor substrate into contact with a rinsing solution (hereinafter also referred to as the "rinsing step") may be performed. By performing the rinsing step, the substrate obtained in the processing step can be washed with the rinsing solution, and residue can be efficiently removed. The rinsing step is preferably performed immediately after the substrate processing step and is a step of rinsing the substrate with the rinsing solution. The rinsing step may be performed using the mechanical stirring method described above.

[0118] Examples of rinse solutions include water (preferably DI water), methanol, ethanol, isopropyl alcohol (IPA), N-methylpyrrolidinone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Alternatively, an aqueous rinse solution with a pH greater than 8.0 (such as diluted aqueous ammonium hydroxide) may be used.

[0119] The method for bringing the rinse solution into contact with the substrate can be similarly applied to the method for bringing the chemical solution into contact with the substrate described above. The contact time between the 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.

[0120] After the rinsing step described above, a drying step may be performed to dry the substrate. Examples of drying methods include spin drying, passing a drying gas over the substrate, heating the substrate using heating means such as a hot plate and an infrared lamp, Marangoni drying, Rotagoni drying, IPA (isopropyl alcohol) drying, and any combination thereof.

[0121] [Method for Manufacturing Electronic Devices] The above substrate processing method can be suitably applied to the manufacturing of electronic devices such as semiconductor devices. The above cleaning method may be carried out in combination before or after other processes performed on the substrate. The above processing method may be incorporated into other processes during the implementation of the above processing method, or the above processing method may be incorporated into other processes. Examples of other processes include the formation of 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, and modification), the formation of resists, exposure processes, removal processes, heat treatment processes, cleaning processes, and inspection processes.

[0122] The above processing method may be performed at any stage of the backend process (BEOL), middle process (MOL), or frontend process (FEOL), and is preferably performed in the frontend process or middle process.

[0123] The present invention will be described in more detail below based on 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 examples shown below. In addition, the containers used for the preparation, filling, and storage of the chemical solution were used after being washed with the solvent used for preparation or the prepared chemical solution.

[0124] [Preparation of Chemical Solution] The method for preparing the chemical solution will be explained using Example 1 as an example. After adjusting the concentration of the specific anion to below the detection limit in ion chromatography (IC) by treating aqueous solutions of polyacrylic acid and ETMAH with an ion exchange resin, the chemical solution of Example 1 was prepared by mixing the aqueous solutions treated with the ion exchange resin, sulfuric acid (a source of the specific anion), and ultrapure water in the proportions shown in the table below, and then thoroughly stirring the resulting mixture using a stirrer. The chemical solutions of Examples 2, 3, and 5-7, and Comparative Examples 1, 2, 8, and 9, which have the compositions shown in the table below, were also prepared in accordance with the preparation method of Example 1. The chemical solutions of the other examples and comparative examples can also be prepared in accordance with the preparation method of Example 1. The content of each component relative to the total mass of the chemical solution (all on a mass basis) is as shown in the table.

[0125] The content of specific anions in the prepared chemical solution can be confirmed by the IC analysis described above. Furthermore, all raw materials used in the preparation of the chemical solution were classified as semiconductor grade or equivalent high-purity grade, and the preparation, filling, and storage of the chemical solution were all carried out in a cleanroom meeting ISO Class 2 or lower standards.

[0126] The following lists the anionic polymers used in the preparation of the chemical solution, the compounds used as sources of specific anions, the additives, and the pH adjusters. The amount of each source of specific anions added is calculated based on the content of each specific anion relative to the total mass of the chemical solution, as shown in "SO ４ ２－ "NO" ３－ "PO ４ ３－ "F － "Cl － ", and "Br － The amount of pH adjuster added was the amount that would result in the value indicated in the "Content" column for each of the following items. In addition, the amount of pH adjuster added was the amount that would result in the pH of the chemical solution being indicated in the "pH of the chemical solution" column.

[0127] (Anionic polymers) Polyacrylic acid poly(acrylic acid-maleic acid) Sulfonated polyacrylic acid (2-acrylamido-2-methylpropanesulfonic acid-acrylic acid copolymer) Poly(phosphino-carboxylic acid) Sulfonated poly(phosphino-carboxylic acid)

[0128] The above sulfonated polyacrylic acid has the following structural units. m and n represent the number of repeating units, and the molar ratio was m / n = 88 / 14.

[0129]

[0130] The above poly(phosphino-carboxylic acid) has the following structural units. Note that s and t represent the number of repeating units, respectively.

[0131]

[0132] The above sulfonated poly(phosphino-carboxylic acid) has the following structural units. x, y, and z represent the number of repeating units, respectively.

[0133]

[0134] (Polymers other than anionic polymers) Polyglycerin, polyethylene glycol, ethylene oxide 9 molar adduct of lauryl alcohol, hydroxyethylcellulose, polyvinylpyrrolidone

[0135] (Source of specific anions) Sulfuric acid (95% by mass sulfuric acid, H ２ SO ４ ) Nitric acid (60% by mass nitric acid, HNO ３ ) Phosphate (H ３ PO ４) Hydrofluoric acid (49% by mass hydrofluoric acid, HF) Hydrochloric acid (HCl) Hydrobromic acid (HBr)

[0136] (Additives) 1,2,4-Triazole monoethanolamine glycine histidine cysteine ​​arginine maleic acid tartaric acid 4-Methoxyphenol HEDP (etidronic acid) AMP (aminomethylpropanol) Tris (tris(hydroxymethyl)aminomethane) trimellitic acid methylisothiazolinone sorbate

[0137] (pH adjuster) ETMAH: Ethyltrimethylammonium hydroxide citrate

[0138] (Solvent) Ultrapure water

[0139] [Evaluation] Using each chemical solution prepared according to the above procedure, the amount of residue after polishing and the amount of residual specific anions were evaluated according to the following procedure. The evaluation method will be explained using Example 1 as an example. Examples 2, 3, and 5-7, as well as Comparative Examples 1, 2, 8, and 9, were also evaluated in accordance with the evaluation method of Example 1. The other examples and comparative examples can also be evaluated in accordance with the evaluation method of Example 1.

[0140] <Amount of residue after polishing> The residue removal efficiency (number of defects) when cleaning semiconductor substrates that had undergone chemical mechanical polishing was evaluated. Using a POLI-400 (polishing device manufactured by G&P Technology, Korea), one of the following polishing solutions was used, and the substrates shown below were polished under the conditions of an average in-plane polishing pressure of 105 hPa, a polishing solution supply rate of 100 mL / min, and a polishing time of 1 minute. Each of the resulting CMP-treated substrates was scrubbed for 1 minute using the chemical solution of Example 1, adjusted to room temperature (23°C), with a ZAB-8S1M (scrub cleaning device manufactured by Kitagawa Grestec), and then dried. The polishing solutions and substrates used for evaluation are shown below. The types of polishing solutions and substrates used in the evaluation of each example and comparative example are listed in the table below.

[0141] (Polishing fluids) CSL9044C (Cu Bulk slurry A, manufactured by Fujifilm Corporation) BSL8400C (Cu Barrier slurry B, manufactured by Fujifilm Corporation) BSL8250C (Cu slurry C for HB (hybrid bonding), manufactured by Fujifilm Corporation) FSL1700C (W slurry D, manufactured by Fujifilm Corporation)

[0142] (Substrate) 2 x 2 cm coupon wafer with copper electroplated film, 2 x 2 cm coupon wafer with tungsten CVD film.

[0143] Next, the number of defects was measured using the following procedure and evaluated based on the following evaluation criteria. Specifically, using a GEMINI500 (ZEISS field emission scanning electron microscope), SEM images were acquired for a total of 1024 sections (32 vertical x 32 horizontal) on the polished (cleaned) surface of the wafer obtained using the above procedure. These sections were then used as a single observation area. Defects on each SEM image were automatically detected and counted using our proprietary AI defect detection software, and the total number of defects on all 1024 SEM images was summed to calculate the total number of defects. A lower number of detected defects indicates superior residue removal performance.

[0144] (Evaluation Criteria) G: More than 10,000 particles of residue after polishing F: More than 1,000 particles of residue after polishing but less than 10,000 E: More than 500 particles of residue after polishing but less than 1,000 D: More than 100 particles of residue after polishing but less than 500 C: More than 50 particles of residue after polishing but less than 100 B: More than 10 particles of residue after polishing but less than 50 A: Less than 10 particles of residue after polishing

[0145] <Amount of Residual Specific Anions> Residual specific anions were detected using the following procedure and evaluated based on the evaluation criteria below. Specifically, TOF-SIMS 5Using a time-of-flight secondary ion mass spectrometer (ION-TOF), ion peaks corresponding to each specific anion remaining on the substrate were detected. The amount of residual specific anions was then evaluated based on the detected peak intensities according to the evaluation criteria below. If ion peaks corresponding to multiple specific anions were detected, the peak intensity was evaluated as the sum of the peaks. A smaller detected peak intensity indicates a lower amount of specific anions remaining on the substrate.

[0146] (Evaluation Criteria) G: Peak intensity of 1.0 × 10⁻⁶ in TOF-SIMS ６ The above F: Peak intensity of 1.0 × 10⁻⁶ in TOF-SIMS. ５ The above is 1.0 x 10 ６ Less than E: Peak intensity in TOF-SIMS is 1.0 × 10⁻⁶ ４ The above is 1.0 x 10 ５ Less than D: Peak intensity of 1.0 × 10⁻⁶ in TOF-SIMS ３ The above is 1.0 x 10 ４ Less than C: Peak intensity of 1.0 × 10⁻⁶ in TOF-SIMS ２ The above is 1.0 x 10 ３ Less than B: Peak intensity of 1.0 × 10⁻⁶ in TOF-SIMS １ The above is 1.0 x 10 ２ Less than A: Peak intensity of 1.0 × 10⁻⁶ in TOF-SIMS １ less than

[0147] The results are shown in the table below. In the table, the notation "E + n (where n is an integer)" means "×10 ＋ｎ This means "[...]." In the table, the column "Anionic Polymer / Specific Anion" represents the mass ratio of the anionic polymer content to the total content of specific anions in the drug solution. Note that "Table 1 (continued)" and "Table 2 (continued)" are the remainders after splitting Table 1 and Table 2, respectively.

[0148]

[0149]

[0150]

[0151]

[0152] The results shown in the table confirm that when the chemical solution of the present invention is used to treat a substrate that has undergone chemical and mechanical polishing, it leaves fewer residual anionic components and less residue on the substrate.

[0153] The residual anionic components and residues on the copper surface are described below. From a comparison between Examples 1 and 2, the mass ratio of the anionic polymer content to the total content of specific anions was 1.0 × 10⁻⁶. ３ In the above cases, it was confirmed that there was less residue. From a comparison of Examples 1 and 3-5, it was confirmed that when the content of a single specific anion was 500 ppb by mass or less relative to the total mass of the chemical solution, there was less residual anionic material on the substrate; when it was 50 ppb by mass or less, there was even less residual anionic material on the substrate; and when it was 5 ppb by mass or less, there was particularly little residual anionic material on the substrate. From a comparison of Examples 1, 21 and 22, it was confirmed that when the pH of the chemical solution was 11.0 or higher, there was less residue; and when it was 12.0 or higher, there was even less residue. From a comparison of Example 1 and 13, it was confirmed that when the chemical solution further contained water-soluble amines (especially alkanolamines), there was even less residual anionic material on the substrate. From a comparison of Example 1 and Examples 14-20, it was confirmed that when the chemical solution further contained organic acids, there was less residue; and in particular, when the organic acid was an amino acid containing a thiol group, there was even less residue. From a comparison between Example 1 and Examples 37-42, it was confirmed that when the chemical solution contains two or more specific anions, the amount of residue is less; when it contains three or more specific anions, the amount of residue is even less; and when it contains four or more specific anions, the amount of residue is particularly low.

[0154] The residual anionic components and residues on the tungsten surface are described below. From a comparison between Examples 46 and 54, the mass ratio of the anionic polymer content to the total content of specific anions was 1.0 × 10⁻⁶. ４In the above cases, it was confirmed that there were fewer residual anionic components. From a comparison of Examples 54 and 55, it was confirmed that when the pH of the chemical solution was 5.5 to 6.5, there were fewer residues. From a comparison of Examples 54 and 56 to 61, it was confirmed that when the chemical solution contained at least one of an organic acid and a water-soluble amine, there were fewer residues, and in particular, when it contained a phosphonic acid compound, there were even fewer residual anionic components. From a comparison of Examples 56 to 71, it was confirmed that when the chemical solution contained three or more additives selected from organic acids, water-soluble amines, and heterocyclic compounds, at least one of the effects of the present invention (residual anionic components and residues) was superior, and when it contained four or more, there were even fewer residues.

Claims

1. A chemical solution used for a substrate that has been subjected to chemical mechanical polishing, comprising: an anionic polymer; SO ４ ２－ , NO ３ － , PO ４ ３－ , F － , Cl － , and Br － one or more specific anions selected from the group consisting of, and water, wherein the total content of the specific anions is 1.0 to 1000 mass ppb relative to the total mass of the chemical solution.

2. The drug solution according to claim 1, wherein the anionic polymer is a polymer containing repeating units having a carboxyl group.

3. The drug solution according to claim 1, wherein the anionic polymer is polyacrylic acid.

4. As the specified anion, at least SO ４ ２－ The drug solution according to claim 1, comprising:

5. The drug solution according to claim 1, wherein the content of the anionic polymer is 0.0002 to 5% by mass with respect to the total mass of the drug solution.

6. The drug solution according to claim 1, wherein the total content of the specified anion is 1.0 to 500 ppb by mass with respect to the total mass of the drug solution.

7. The drug solution according to claim 1, wherein the total content of the specified anion is 1.0 to 50 ppb by mass with respect to the total mass of the drug solution.

8. SO ４ ２－ and NO ３ － It includes at least NO ３ － SO486 ４ ２－ The mass ratio of the content is 1.0 to 1.0 × 10 ３ The drug solution according to claim 1.

9. As the specified anion, SO ４ ２－ NO ３ － , and PO ４ ３－ It includes at least one of the following, SO ４ ２－ NO ３ － , and PO ４ ３－ The drug solution according to claim 1, wherein the total content of is 60 ppb by mass or less relative to the total mass of the drug solution.

10. The mass ratio of the content of the anionic polymer to the total content of the specified anions is 1.0 × 10 ３ ~1.0 x 10 ５ The drug solution according to claim 1.

11. The chemical solution according to claim 1, which substantially contains neither an oxidizing agent nor abrasive particles.

12. The drug solution according to claim 1, further comprising at least one of a quaternary ammonium compound and a polycarboxylic acid.

13. The drug solution according to claim 1, wherein the pH is 10.0 to 13.

0.

14. The drug solution according to claim 1, wherein the pH is 5.5 to 6.

5.

15. The chemical solution according to claim 1, used as a cleaning solution for the substrate.

16. The chemical solution according to claim 15, wherein the substrate is used for hybrid bonding and has been subjected to chemical and mechanical polishing.

17. A method for processing a substrate, comprising the step of bringing a substrate that has undergone chemical and mechanical polishing treatment into contact with a chemical solution according to any one of claims 1 to 16.

18. The method for processing a substrate according to claim 17, wherein the substrate includes a copper region.

19. A method for manufacturing an electronic device, comprising the substrate processing method described in claim 17.

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