Chemical solution, chemical solution production method, and semiconductor device production method

Abstract

The present invention addresses the problem of providing: a chemical solution which has low turbidity, and of which the etching properties with respect to SiOCN-containing materials have been suppressed and the etching properties with respect to SiGe-containing material are good; a chemical solution production method; and a semiconductor device production method. The chemical solution according to the present invention comprises an etchant compound, a cationic polymer, and an anionic polymer, wherein, when the content of the cationic polymer relative to the total mass of the chemical solution is defined as content X, and the content of the anionic polymer relative to the total mass of the chemical solution is defined as content Y, the chemical solution satisfies the relationship of formula (1) or (2).　Formula (1): 6≤Y / X Formula (2): 6≤X / Y

Description

Chemical solution, chemical solution manufacturing method, and semiconductor device manufacturing method

[0001] The present invention relates to a chemical solution, a method for manufacturing the chemical solution, and a method for manufacturing a semiconductor device.

[0002] As semiconductor devices become increasingly miniaturized, there is an increasing demand for highly efficient and accurate chemical etching and cleaning processes during the semiconductor device manufacturing process. In particular, when multiple materials exist on a substrate, it is desirable to be able to selectively remove a specific material.

[0003] On the other hand, Patent Document 1 describes a method for treating wastewater from a photolithography process, which comprises adding to wastewater from a photolithography process an anionic polymer obtained by polymerizing at least 10 mol % or more of a monomer having an anionic functional group or by a polymer reaction, and a cationic polymer obtained by polymerizing at least 10 mol % or more of a monomer having a cationic functional group or by a polymer reaction, stirring the mixture, and then performing solid-liquid separation ([Claim 1]).

[0004] JP 2012-179529 A

[0005] The present inventors focused on the processing method described in Patent Document 1 and investigated a chemical solution in which a cationic polymer and an anionic polymer were added to an etchant compound. As a result, they found that it is difficult to selectively remove a specific material, specifically, to improve the etching ability for silicon germanium (SiGe)-containing materials while suppressing the etching ability for silicon oxycarbon nitride (SiOCN)-containing materials, and that it is particularly difficult to achieve these etching performances with a chemical solution having low turbidity.

[0006] Therefore, an object of the present invention is to provide a chemical solution that has low turbidity, suppresses etching properties for SiOCN-containing materials, and exhibits good etching properties for SiGe-containing materials, as well as a method for manufacturing the chemical solution and a method for manufacturing a semiconductor device.

[0007] As a result of intensive research into the above-mentioned problems, the present inventors have found that a chemical solution containing an etchant compound, a cationic polymer, and an anionic polymer, in which the content X of the cationic polymer relative to the total mass of the chemical solution and the content Y of the anionic polymer relative to the total mass of the chemical solution satisfy a predetermined relationship, has low turbidity, suppresses etching properties for SiOCN-containing materials, and exhibits good etching properties for SiGe-containing materials, and have completed the present invention. That is, the present inventors have found that the above-mentioned problems can be solved by the following configuration.

[0008] [1] A chemical solution comprising an etchant compound, a cationic polymer, and an anionic polymer, wherein the chemical solution satisfies the relationship of the following formula (1) or (2), where X is the content of the cationic polymer relative to the total mass of the chemical solution, and Y is the content of the anionic polymer relative to the total mass of the chemical solution. Formula (1) 6≦Y / X Formula (2) 6≦X / Y [2] The chemical solution according to [1], wherein the content of the anionic polymer is 0.0001 to 0.03 mass% relative to the total mass of the chemical solution. [3] The chemical solution according to [1] or [2], wherein the content of the cationic polymer is 0.01 to 0.05 mass% relative to the total mass of the chemical solution. [4] The chemical solution according to any of [1] to [3], wherein the anionic polymer has acidic groups capable of dissociating in an amount of 1% or more in the chemical solution. [5] The chemical solution according to any one of [1] to [4], wherein the anionic polymer has at least one group selected from the group consisting of a sulfonic acid group, a phosphonic acid group, and a carboxylic acid group. [6] The chemical solution according to any one of [1] to [5], wherein the cationic polymer has at least one group selected from the group consisting of a tertiary amino group and a quaternary ammonium salt group. [7] The chemical solution according to any one of [1] to [6], wherein the cationic polymer has a quaternary ammonium salt group. [8] The chemical solution according to any one of [1] to [7], wherein the etchant compound contains a fluoride ion source. [9] The chemical solution according to any one of [1] to [8], further containing an oxidizing agent.

[10] The chemical solution according to [9], wherein the content of the oxidizing agent is 0.01 to 10 mass % relative to the total mass of the chemical solution.

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

[10] , wherein the chemical solution is applied to a substrate having a silicon oxycarbonitride content.

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

[10] , which is applied to a substrate containing silicon germanium.

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

[10] , which is applied to a substrate containing silicon oxycarbonitride and silicon germanium.

[14] A method for manufacturing a chemical solution according to any one of [1] to

[13] , wherein the chemical solution is prepared by adding a polymer with a low content to a precursor liquid containing a cationic polymer and an anionic polymer with a high content and not containing a polymer with a low content, out of the cationic polymer and the anionic polymer contained in the chemical solution.

[15] A method for manufacturing a semiconductor device, using the chemical solution according to any one of [1] to

[13] .

[0009] According to the present invention, it is possible to provide a chemical solution that has low turbidity, suppresses etching properties for SiOCN-containing materials, and exhibits good etching properties for SiGe-containing materials, as well as a method for manufacturing the chemical solution and a method for manufacturing a semiconductor device.

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the upper and lower limits. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with the upper or lower limit of another stepwise manner. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with a value shown in the Examples. In this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. When two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified.

[0011] In this specification, "(meth)acrylate" is a notation representing "acrylate" or "methacrylate", "(meth)acrylic" is a notation representing "acrylic" or "methacrylic", "(meth)acryloyl" is a notation representing "acryloyl" or "methacryloyl", and "(meth)acrylic acid" is a notation representing "acrylic acid" or "methacrylic acid".

[0012] In this specification, the term "SiOCN-containing material" refers to a material containing Si, O, C, and N elements, and is preferably a material composed essentially of only Si, O, C, and N elements. The term "substantially" means that the total content of Si, O, C, and N elements is 90 atomic % or more relative to the total atoms of the material. A material composed essentially of only Si, O, C, and N elements may contain other elements (e.g., B, P, etc.) as long as the total content of Si, O, C, and N elements is within the above range. The total content of Si, O, C, and N elements in the SiOCN-containing material is preferably 90 to 100 mass %, more preferably 99 to 100 mass %, and even more preferably 99.9 to 100 mass %, relative to the total mass of the SiOCN-containing material.

[0013] As used herein, the term "SiGe-containing material" refers to a material containing Si and Ge elements, and is preferably a material substantially composed of only Si and Ge elements. The term "substantially" means that the total content of Si and Ge elements is 90 atomic % or more relative to the total atoms of the material. A material substantially composed of only Si and Ge elements may contain other elements (e.g., C, N, O, B, and P) as long as the total content of Si and Ge elements is within the above range. The total content of Si and Ge elements in the SiGe-containing material is preferably 90 to 100 mass %, more preferably 99 to 100 mass %, and even more preferably 99.9 to 100 mass %, relative to the total mass of the SiGe-containing material. In the SiGe-containing material, the content of Ge elements (Ge / (Si+Ge)) relative to the total content of Si and Ge elements is preferably 60 atomic % or less, more preferably 50 atomic % or less, and even more preferably 45 atomic % or less. The lower limit of the content of Ge element relative to the total content of Si element and Ge element is preferably 5 atomic % or more, and more preferably 25 atomic % or more.

[0014] Unless otherwise specified, each component of the drug solution described in this specification may be ionized in the drug solution or may form a salt.

[0015] [Chemical Solution] The chemical solution of the present invention is a chemical solution containing an etchant compound, a cationic polymer, and an anionic polymer, and satisfies the relationship of the following formula (1) or (2), where the content of the cationic polymer relative to the total mass of the chemical solution is the content X, and the content of the anionic polymer relative to the total mass of the chemical solution is the content Y. Formula (1) 6≦Y / X Formula (2) 6≦X / Y

[0016] As described above, the chemical solution of the present invention has low turbidity, suppresses etching ability for SiOCN-containing materials, and exhibits good etching ability for SiGe-containing materials. The reason why these effects are exhibited is not clear in detail, but the inventors speculate as follows. First, SiOCN-containing materials are etched by SiO ２ and Si ３ N ４ Since the cationic polymer has both elements, ２ The anionic polymer acts as an inhibitor of Si ３ N ４ It is believed that the content X of the cationic polymer and the content Y of the anionic polymer relative to the total mass of the chemical solution satisfy the above-mentioned formula (1) or (2), thereby suppressing the formation of precipitates (ion complexation) that accompanies the combined use of a cationic polymer and an anionic polymer, while exerting the function as an inhibitor, thereby suppressing the etching property for SiOCN-containing materials and improving the etching property for SiGe-containing materials.

[0017] In the present invention, for the reasons why turbidity is low, etching properties for SiOCN-containing materials are further suppressed, and etching properties for SiGe-containing materials are better (hereinafter also abbreviated as "reasons why the effects of the present invention are superior"), when the content of the cationic polymer relative to the total mass of the chemical solution is content X and the content of the anionic polymer relative to the total mass of the chemical solution is content Y, it is preferable to satisfy the relationship of the following formula (1-1) or (2-1), more preferably the relationship of the following formula (1-2) or (2-2), and even more preferably the relationship of the following formula (1-3) or (2-3). Formula (1-1) 8≦Y / X Formula (2-1) 8≦X / Y Formula (1-2) 9≦Y / X≦80 Formula (2-2) 9≦X / Y≦80 Formula (1-3) 9≦Y / X≦50 Formula (2-3) 9≦X / Y≦50

[0018] The etchant compound, cationic polymer, anionic polymer, and optional components contained in the chemical solution of the present invention will be described in detail below.

[0019] [Etchant Compound] The etchant compound contained in the chemical solution of the present invention is not particularly limited, and chemical solutions of acids, alkalis, or alkali metal salts can be used as appropriate. Examples of acids include hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, hydrogen peroxide, and acetic acid. Examples of alkalis include caustic soda and caustic potassium. Examples of alkali metal salts include alkali metal silicates such as sodium silicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal aluminates such as sodium aluminate and potassium aluminate; alkali metal aldonic acid salts such as sodium gluconate and potassium gluconate; and alkali metal hydrogen phosphates such as sodium diphosphate, potassium diphosphate, sodium triphosphate, and potassium triphosphate.

[0020] <Fluoride Ion Source> In the present invention, the etchant compound preferably contains a fluoride ion source, because the effects of the present invention are more excellent. Here, the fluoride ion source is a fluoride ion source that generates fluoride ions (F －) or a compound capable of releasing a fluoride ion source. The fluoride ion source may be in the form of a fluoride ion or a fluorine-containing ion. Examples of fluorine-containing ions include bifluoride ions (HF ２ － ), SiF ６ ２－ , TiF ６ ２－ , ZrF ６ ２－ , P.F. ６ － , and BF ４ － The fluoride ion source is often a salt of a fluoride ion or a fluorine-containing ion with a cation. Preferred cations contained in the fluoride ion source include H ＋ , Li ＋ , Na ＋ , K. ＋ , and N.H. ４ ＋ are mentioned, and H ＋ is preferred.

[0021] Examples of fluoride ion sources include hydrofluoric acid (HF) and ammonium fluoride (NH ４ F), hexafluorosilicic acid and its salts (H ２ SiF ６ , Na ２ SiF ６ etc.), fluoroboric acid and its salts (KBF ４ , N.H. ４ BF ４ etc.), fluoroboric acid, hexafluorotitanic acid (H ２ TiF ６ ), hexafluorozirconate (H ２ ZrF ６ ), hexafluorophosphate (HPF ６ ), and hexafluoroboric acid (HBF ４ ) are exemplified, hydrofluoric acid or ammonium fluoride is preferred, and hydrofluoric acid is more preferred.

[0022] The etchant compound may be used alone or in combination of two or more. The content of the etchant compound is preferably 0.005 to 10.0 mass %, more preferably 0.01 to 5.0 mass %, and even more preferably 0.1 to 1.0 mass %, relative to the total mass of the chemical solution, because this provides better effects of the present invention. As the etchant compound (particularly, a fluoride ion source), a solution containing a fluoride ion source may be used. When a solution containing a fluoride ion source is used as the etchant compound, the content of the etchant compound is the content of the fluoride ion source contained in the solution.

[0023] [Cationic Polymer] The cationic polymer contained in the chemical solution of the present invention is a polymer having a repeating unit having a functional group (hereinafter also referred to as "cationic group") that exhibits cationicity when dissolved in water, such as a tertiary amino group, and is preferably a polymer having a cationic group that exhibits a pKa value higher than the pH value of the chemical solution minus 2. Examples of the cationic group include a nitrogen-containing group. Examples of the nitrogen-containing group include an amino group (-NR Ｎ ２ ), quaternary ammonium base (-N ＋ R Ｎ ３ ), a hydrazine group, a guanidine group, and a nitrogen-containing heterocyclic group. Ｎ R each independently represents a hydrogen atom or an organic group (a group containing at least one carbon atom). Ｎ The number of carbon atoms in the organic group represented by the formula (I) is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 3. Examples of the nitrogen-containing heterocyclic group include nitrogen-containing aromatic heterocyclic groups such as a pyrrole group, an imidazole group, a pyrazole group, an oxazolyl group, a triazole group, a benzimidazole group, a benztriazole group, a pyridyl group, and a triazine group, and nitrogen-containing aliphatic heterocyclic groups such as a pyrrolidinyl group, a piperidinyl group, and a piperazinyl group.

[0024] The upper limit of the weight average molecular weight of the cationic polymer is not particularly limited, but is preferably not more than 100,000, more preferably not more than 80,000, and even more preferably not more than 50,000. The lower limit of the weight average molecular weight of the cationic polymer is not particularly limited, but is preferably not less than 500, more preferably not less than 800, and even more preferably not less than 1,500. Here, the weight average molecular weights of the cationic polymer and the anionic polymer described below are defined as polystyrene-equivalent values ​​measured by GPC (Gel Permeation Chromatography) using a GPC apparatus (Prominence UFLC manufactured by Shimadzu Corporation) [eluent: tetrahydrofuran, flow rate (sample injection amount): 50 μL, column: TSKgel GMHxL, TSKgel G4000HxL, TSKgel G2000HxL manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: differential refractive index detector].

[0025] In the present invention, for reasons of achieving better effects of the present invention, the cationic polymer preferably has at least one cationic group selected from the group consisting of a tertiary amino group and a quaternary ammonium salt group, and more preferably has a quaternary ammonium salt group. The cationic polymer preferably contains a repeating unit having a cationic group. The number of cationic groups contained in the repeating unit having a cationic group is preferably 1 to 6, more preferably 1 or 2, and even more preferably 1.

[0026] The repeating unit having a cationic group is preferably a repeating unit represented by general formula (1-a) or a repeating unit represented by general formula (1-b).

[0027]

[0028] In general formula (1-a), L １ａ and L ２ａ each independently represents a single bond or a methylene group. １ａ is a single bond, L ２ａ is a methylene group, and L １ａis a methylene group, L ２ａ is a single bond. １ａ is preferably a single bond, and L ２ａ is preferably a methylene group.

[0029] In general formula (1-a), X represents a group represented by formula (X1) or a group represented by formula (X2). * represents a bonding position. In formula (X1) and formula (X2), R １ａ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, or an aralkyl group having 7 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group may be linear, branched, or cyclic, and examples thereof include alkyl groups having 1 to 4 carbon atoms which may have a hydroxyl group, of which methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl, or cyclohexyl groups are preferred. Examples of aralkyl groups having 7 to 10 carbon atoms include benzyl, methylbenzyl, naphthylmethyl, and phenethyl groups. R １ａ Among these, a hydrogen atom, a methyl group, an ethyl group, or a benzyl group is preferable as the aryl group.

[0030] In formula (X2), D － represents a monovalent anion. － Examples of the monovalent anion represented by the formula (I) include a halide ion (e.g., a chloride ion), a sulfate ion, a nitrate ion, an acetate ion, a methyl sulfate ion, an ethyl sulfate ion, a sulfamate ion, and a hydroxide ion.

[0031] In general formula (1-b), L １ｂ and L ２ｂ each independently represents a single bond or a methylene group. １ｂ is a single bond, L ２ｂ is a methylene group, and L １ｂ is a methylene group, L ２ｂ is a single bond. １ｂis preferably a single bond, and L ２ｂ is preferably a methylene group.

[0032] In general formula (1-b), R １ｂ and R ２ｂ each independently represents an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, or an aralkyl group having 7 to 10 carbon atoms. Specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group and the aralkyl group having 7 to 10 carbon atoms are １ａ These are the same as the specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms and optionally having a hydroxyl group, and the aralkyl group having 7 to 10 carbon atoms, represented by the following formula:

[0033] In general formula (1-b), D － represents a monovalent anion. － Examples of the monovalent anion represented by the formula (X2) include D － Examples of the monovalent anion include the ions exemplified above.

[0034] In general formula (1-b), R １ｂ , R ２ｂ and D － Examples of the combination of D are shown in Examples 1 to 5 below, and among them, Examples 1, 5 and 6 are preferred. － The chloride ion represented by the formula (I) may be replaced by an anion selected from bromide, iodide, methyl sulfate and ethyl sulfate.

[0035] Example 1: R １ｂ =R ２ｂ = methyl group, D － = Chloride ion Example 2: R １ｂ =R ２ｂ = ethyl group, D － = chloride ion Example 3: R １ｂ =R ２ｂ = propyl group, D － = chloride ion Example 4: R １ｂ =R ２ｂ = butyl group, D － = chloride ion Example 5: R １ｂ = ethyl group, R ２ｂ = benzyl group, D－ = chloride ion Example 6: R １ｂ = methyl group, R ２ｂ = ethyl group, D － = Ethyl sulfate ion

[0036] The repeating unit having a cationic group may be a repeating unit represented by general formula (1-c).

[0037]

[0038] In general formula (1-c), Y represents a group represented by formula (Y1) or a group represented by formula (Y2). * represents a bonding position. L represents a single bond or a divalent linking group. Examples of the divalent linking group include a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, -O-, -CO-, and -SO ２ -, -NR Ｌ -, -P(=O)(-O － )- and groups formed by combining these. Ｌ The definition of R Ｎ It is the same as R １ｃ and R ２ｃ each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, or an aralkyl group having 7 to 10 carbon atoms. Specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group and the aralkyl group having 7 to 10 carbon atoms are １ａ These are the same as the specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms and optionally having a hydroxyl group, and the aralkyl group having 7 to 10 carbon atoms, represented by the following formula: － represents a monovalent anion. － Examples of the monovalent anion represented by the formula (X2) include D － Examples of the monovalent anion include the ions exemplified above.

[0039] The content of the repeating unit having the cationic group is preferably from 30 to 100 mol %, more preferably from 50 to 80 mol %, based on the total repeating units of the cationic polymer.

[0040] The cationic polymer may contain repeating units other than the repeating units having the cationic group.

[0041] Examples of such cationic polymers include cationic polygalactomannans such as cationic guar gum, cationic tara gum, and cationic locust bean gum; cationic cellulose; cationic hydroxyalkyl celluloses such as cationic hydroxyethyl cellulose and cationic hydroxypropyl cellulose; cationic starch; cationic polyvinyl alcohol; quaternized dialkylaminoalkyl (meth)acrylate polymers such as vinylpyrrolidone / N,N-dimethylaminoethyl diethyl methacrylate sulfate copolymer and N,N-dimethylaminoethyl diethyl methacrylate sulfate / N,N-dimethylacrylamide / polyethylene glycol dimethacrylate copolymer; polydiallyldimethylammonium chloride, diallyldimethylammonium chloride / acrylic acid copolymer, diallyldimethylammonium chloride / acrylamide copolymer, diallyldimethylammonium chloride / acrylic acid / acrylamide copolymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride / sulfur dioxide copolymer, and diallyldimethylammonium chloride. Diallyl quaternary ammonium salt polymers such as acrylamide copolymers, diallylamine amide sulfate-maleic acid copolymers, methyldiallylamine-maleic acid copolymers, diallyldimethylammonium chloride-maleic acid copolymers, diallylmethylethylammonium ethyl sulfate-sulfur dioxide copolymers, and maleic acid-diallyldimethylammonium ethyl sulfate-sulfur dioxide copolymers; vinylimidazolium trichloride / vinylpyrrolidone copolymers; vinylpyrrolidone / alkylaminoalkyl (meth)acrylate copolymers; vinylpyrrolidone / alkylaminoalkyl (meth)acrylate / vinylcaprolactam copolymers; vinylpyrrolidone / (meth)acrylamidopropyl trimethylammonium chloride copolymers; alkylacrylamide / (meth)acrylate / alkylaminoalkylacrylamide / polyethylene glycol (meth)acrylate copolymers; adipic acid / dimethylaminohydroxypropyl ethylenetriamine copolymers; acrylic acid-methyl acrylate-methacrylamidopropyl trimethylammonium chloride copolymers (polyquaternium-47);Acrylic acid, acrylamide, methacrylamidepropyltrimethylammonium chloride (Polyquaternium-53); methacryloylethyldimethylbetaine, methacryloylethyltrimethylammonium chloride, methoxypolyethylene glycol methacrylate copolymer (Polyquaternium-49); methacryloylethyldimethylbetaine, methacryloylethyltrimethylammonium chloride, 2-hydroxyethyl methacrylate copolymer (Polyquaternium-48); diallyldimethylammonium chloride, acrylic acid Examples of the cationic polymer include acrylamide copolymer (Polyquaternium-7); acrylamide / acrylic acid / dimethyldiallylammonium chloride copolymer (Polyquaternium-39); N,N-dimethylaminoethyl diethyl methacrylate sulfate / N,N-dimethylacrylamide / polyethylene glycol dimethacrylate copolymer (Polyquaternium-52); and cationic polymers described in JP-A-53-139734 and JP-A-60-36407, and these may be used alone or in combination of two or more. Among these cationic polymers, polymers containing chloride ions may be polymers from which the chloride ions have been removed.

[0042] In the present invention, the content of the cationic polymer is preferably 0.0001 to 0.3 mass %, more preferably 0.001 to 0.1 mass %, and even more preferably 0.01 to 0.05 mass %, relative to the total mass of the chemical solution, for reasons of better effects of the present invention.

[0043] [Anionic Polymer] The anionic polymer contained in the chemical solution of the present invention is a polymer having a repeating unit having a functional group (hereinafter also referred to as an "anionic functional group") that exhibits anionic properties when dissolved in water, such as a sulfonic acid group, and is preferably a polymer having an anionic group that exhibits a pKa value lower than the pH value of the chemical solution + 2.

[0044] The upper limit of the weight-average molecular weight of the anionic polymer is not particularly limited, but is preferably not more than 100,000, more preferably not more than 80,000, and even more preferably not more than 50,000. The lower limit of the weight-average molecular weight of the anionic polymer is not particularly limited, but is preferably not less than 500, more preferably not less than 800, and even more preferably not less than 1,500.

[0045] In the present invention, the effect of the present invention is more excellent because the anionic polymer dissociates in the chemical solution by 1% or more (protons (H ＋ It is preferable that the anionic polymer has an acidic group capable of releasing a dissociable group (e.g., a hydroxyl group). Here, the term "dissociable acidic group" refers to an acidic group that dissociates due to the effects of pH, ionic strength, temperature, etc. when the anionic polymer is present in a drug solution. Furthermore, "dissociating at least 1%" refers to 1% or more of the total number of acidic groups possessed by the anionic polymer being dissociated, which can be determined simply by pH ≥ pKa-2.

[0046] In the present invention, the anionic polymer preferably contains a sulfonic acid group or a phosphonic acid group (-PO ３ H ２ ), phosphinic acid group (-PO ２ H ２ ), phosphate group (-PO ４ H ２ Preferably, the anionic polymer has at least one anionic group selected from the group consisting of a carboxylic acid group, a carboxylic acid group, and a phenolic hydroxy group, more preferably a sulfonic acid group or a phosphonic acid group, and even more preferably a sulfonic acid group. The anionic polymer preferably contains a repeating unit having an anionic group. The number of anionic groups contained in the repeating unit having an anionic group is preferably 1 to 6, more preferably 1 or 2, and even more preferably 1.

[0047] Examples of the repeating unit having an anionic group include a repeating unit represented by the following formula (2-a):

[0048]

[0049] In formula (2-a), R ｂ１ , R ｂ２ and R ｂ３ each independently represents a hydrogen atom, an alkyl group, or a functional group having an acidic group. ｂ represents a single bond or a (k+1)-valent linking group. A represents an anionic group. k represents an integer of 1 to 4. When a plurality of acidic groups are present in formula (2-a), the plurality of acidic groups may be the same or different.

[0050] The alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3. Examples of the functional group having an acidic group include -L in formula (2-a): ｂ -(A) ｋ Examples of the group include a group represented by the following formula: ｂ , A and k will be described in detail later. ｂ１ , R ｂ２ and R ｂ３ is preferably a hydrogen atom, a methyl group, an ethyl group, or a carboxy group, and more preferably a hydrogen atom, a methyl group, or a carboxy group. ｂ１ , R ｂ２ and R ｂ３ It is preferred that one of represents a hydrogen atom, a methyl group or a carboxy group, and the remaining two each represent a hydrogen atom.

[0051] L ｂ The (k+1)-valent linking group represented by the formula (I) is not particularly limited as long as it is a group having a valence corresponding to the number of A, and examples thereof include an optionally substituted di- to pentavalent aliphatic hydrocarbon group, an optionally substituted di- to pentavalent aromatic hydrocarbon group, an optionally substituted di- to pentavalent aromatic heterocyclic group, -O-, -CO-, -SO ２ -, -NR Ｌ -, -N<, and groups formed by combining these. Ｌ The definition of R Ｎ When k is 1, the divalent linking group may be a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, —O—, —CO—, —SO２ -, -NR Ｌ -, and groups formed by combining these. As the divalent aliphatic hydrocarbon group, an alkylene group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms) is preferred. L ｂ is more preferably a single bond, a methylene group, or a phenylene group.

[0052] Specific examples of the anionic group represented by A are as described above. k is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0053] Examples of such anionic polymers include polyacrylic acid; styrene-acrylic acid copolymer; styrene-maleic acid copolymer; copolymer of 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid; copolymer of 2-acrylamido-2-methylpropanesulfonic acid and maleic acid; copolymer of 3-allyloxy-2-hydroxy-1-propanesulfonic acid and acrylic acid; copolymer of 3-allyloxy-2-hydroxy-1-propanesulfonic acid and maleic acid; copolymer of 2-acrylamido-2-methylpropanesulfonic acid and 3-allyloxy- Examples of the copolymer include a copolymer of acrylic acid and a copolymer of 2-hydroxy-1-propanesulfonic acid and maleic acid; a copolymer of 2-acrylamido-2-methylpropanesulfonic acid, 3-allyloxy-2-hydroxy-1-propanesulfonic acid and maleic acid; a copolymer of maleic acid and a copolymer of maleic acid; a sulfonic acid-modified polyvinyl alcohol; a copolymer of styrenesulfonic acid and maleic acid; a copolymer of styrenesulfonic acid and styrene; a naphthalenesulfonic acid formalin condensate; and poly-p-styrenesulfonic acid. These may be used alone or in combination of two or more.

[0054] In the present invention, the content of the anionic polymer is preferably 0.0001 to 0.03 mass%, more preferably 0.0003 to 0.006 mass%, and even more preferably 0.0006 to 0.003 mass%, relative to the total mass of the chemical solution, because the effects of the present invention are more excellent.

[0055] [Oxidizing Agent] The chemical solution of the present invention preferably contains an oxidizing agent for the reason that the effects of the present invention are more excellent. The lower limit of the standard oxidation-reduction potential of the oxidizing agent is not particularly limited, but is preferably 1.0 V or more, more preferably 1.3 V or more, and even more preferably 1.5 V or more. The upper limit of the standard oxidation-reduction potential of the oxidizing agent is not particularly limited, but is preferably 4.0 V or less, more preferably 2.5 V or less. The above standard oxidation-reduction potential is based on a standard hydrogen electrode.

[0056] Examples of the oxidizing agent include hydrogen peroxide, and peroxides such as peracetic acid, performic acid, perpropionic acid, and salts thereof; perhalogen acid compounds such as periodic acid, perchloric acid, and salts thereof; oxide halides such as iodic acid, chloric acid, hypochlorous acid, and salts thereof; nitric acid compounds such as nitric acid, cerium nitrate, and iron nitrate; persulfates, persulfates, persulfates, peroxodisulfate, and peroxodisulfate; persulfides; percarbonates; perboric acid and salts thereof; permanganates; isocyanuric acid compounds such as isocyanuric acid, trichloroisocyanuric acid, and salts thereof; cerium compounds; and ferricyanides such as potassium ferricyanide. Peroxides or perhalogen acid compounds are preferred, and perhalogen acid compounds are more preferred. The periodic acid includes metaperiodic acid (HIO ４ ), and orthoperiodic acid (H ５ IO ６ ) are included. Among them, the oxidizing agent is preferably periodic acid (standard oxidation-reduction potential 1.6 V), hydrogen peroxide (standard oxidation-reduction potential 1.8 V), peracetic acid (standard oxidation-reduction potential 1.4 V), performic acid, or perpropionic acid, with periodic acid being more preferred. Note that the chemical solution may contain a component resulting from a reaction between the oxidizing agent and a solvent described below. For example, when the chemical solution contains hydrogen peroxide, an acidic compound (e.g., sulfuric acid), and acetic acid, part of the hydrogen peroxide may react with the acetic acid to generate peracetic acid, and the peracetic acid may function as the oxidizing agent.

[0057] The oxidizing agent may be used alone or in combination of two or more. The content of the oxidizing agent is preferably 0.01 to 10 mass %, more preferably 0.1 to 5 mass %, and even more preferably 0.6 to 3 mass %, based on the total mass of the chemical solution, because this provides a more excellent effect of the present invention.

[0058] [Solvent] The chemical solution of the present invention preferably contains a solvent. Examples of the solvent include water and an organic solvent. The organic solvent is preferably a water-soluble organic solvent. The water-soluble organic solvent refers to an organic solvent having a solubility in water (100 g) at 25°C of 20 g / 100 g or more. For reasons of superior effects of the present invention, the solvent preferably contains a water-soluble organic solvent, and more preferably contains water and a water-soluble organic solvent.

[0059] Examples of organic solvents include alcohol-based solvents, carboxylic acid-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, ketone-based solvents, sulfone-based solvents, amide-based solvents, and nitrile-based solvents. Of these, solvents selected from the group consisting of alcohol-based solvents, carboxylic acid-based solvents, ether-based solvents, and sulfoxide-based solvents are preferred, and carboxylic acid-based solvents are more preferred.

[0060] Examples of alcohol solvents include methanol, ethanol, 1-propanol, 2-propanol, t-butyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, 2-pentanol, t-pentyl alcohol, hexanol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 1-methoxy-2-butanol, allyl alcohol, propargyl alcohol, 2-butenyl alcohol, 3-butenyl alcohol, 4-penten-2-ol, tetrahydrofurfuryl alcohol, furfuryl alcohol, and and benzyl alcohol, and polyols such as glycerin, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, hexylene glycol, pinacol, and 1,3-cyclopentanediol.

[0061] Examples of carboxylic acid solvents include formic acid, acetic acid, and propionic acid.

[0062] Examples of ether solvents include dialkyl ethers such as diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, and cyclohexyl methyl ether; glycol ethers such as ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol propyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and triethylene glycol monobutyl ether; and cyclic ethers such as tetrahydrofuran and 1,4-dioxane.

[0063] An example of a sulfoxide solvent is dimethyl sulfoxide (DMSO).

[0064] Examples of ester solvents include chain esters such as ethyl acetate, butyl acetate, ethyl lactate, methyl 3-methoxypropanoate, propylene glycol monomethyl ether acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, and propylene glycol diacetate, and cyclic esters such as propylene carbonate, ethylene carbonate, and diethyl carbonate.

[0065] Examples of solvents other than those mentioned above include ketone solvents such as acetone, dimethyl ketone (propanone), cyclobutanone, cyclopentanone, cyclohexanone, methyl ethyl ketone (2-butanone), 5-hexanedione, methyl isobutyl ketone, 1,4-cyclohexanedione, 1,3-cyclohexanedione, and cyclohexanone; amide solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, formamide, N-methylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropanamide, and hexamethylphosphoric triamide; sulfone solvents such as sulfolane, 3-methylsulfolane, and 2,4-dimethylsulfolane; and nitrile solvents such as acetonitrile.

[0066] The water-soluble organic solvent preferably contains at least one selected from the group consisting of formic acid, acetic acid, propionic acid, and ethylene glycol monobutyl ether (EGBE), more preferably contains at least one selected from the group consisting of acetic acid, propionic acid, and EGBE, and even more preferably contains acetic acid.

[0067] The solvent may be used alone or in combination of two or more. The lower limit of the solvent content is not particularly limited, but is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, relative to the total mass of the chemical solution. The upper limit of the solvent content is not particularly limited, but is less than 100% by mass, preferably 99.5% by mass or less, and more preferably 99% by mass or less, relative to the total mass of the chemical solution. When the chemical solution of the present invention contains a water-soluble organic solvent, the lower limit of the water-soluble organic solvent content is not particularly limited, but is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, relative to the total mass of the chemical solution. The upper limit of the water-soluble organic solvent content is not particularly limited, but is preferably 95% by mass or less, more preferably less than 90% by mass, and even more preferably 80% by mass or less, relative to the total mass of the chemical solution.

[0068] [Other Additives] The chemical solution of the present invention may contain additives other than the above-mentioned components. Examples of other additives include basic compounds, acidic compounds, surfactants, antifoaming agents, and unsaturated compounds. Note that all of these components are compounds different from the above-mentioned etchant compound, cationic polymer, anionic polymer, and oxidizing agent.

[0069] <Basic Compound> The chemical solution may contain a basic compound. Examples of the basic compound include organic basic compounds and inorganic basic compounds. Examples of the organic basic compound include amine compounds, quaternary ammonium salts, amine oxide compounds, nitro compounds, nitroso compounds, oxime compounds, ketoxime compounds, aldoxime compounds, lactam compounds, and isocyanide compounds. Note that the organic basic compound is a compound different from the heterocyclic compound described above. Examples of the inorganic basic compound include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides, and ammonia or salts thereof.

[0070] The content of the basic compound is not particularly limited, but is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total mass of the chemical solution.

[0071] <Acidic Compound> The chemical solution may contain an acidic compound. Examples of the acidic compound include inorganic acidic compounds. Examples of the inorganic acidic compound include hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, and phosphonic acid, and sulfuric acid is preferred.

[0072] The content of the acidic compound is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the chemical solution.

[0073] <Surfactant> The chemical solution may contain a surfactant. The surfactant is not particularly limited as long as it is a compound having a hydrophilic group and a hydrophobic group (lipophilic group) in one molecule, and examples thereof include nonionic surfactants, cationic surfactants, and anionic surfactants. Surfactants often have at least one hydrophobic group selected from the group consisting of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof. The total carbon number of the surfactant is preferably 16 to 100.

[0074] Examples of the nonionic surfactant include ester-type nonionic surfactants, ether-type nonionic surfactants, and ester-ether-type nonionic surfactants, and ether-type nonionic surfactants are preferred. Examples of the nonionic surfactant include the compounds exemplified in paragraph

[0126] of WO 2022 / 044893, the contents of which are incorporated herein by reference.

[0075] Examples of cationic surfactants include primary to tertiary alkylamine salts (e.g., monostearyl ammonium chloride, distearyl ammonium chloride, and tristearyl ammonium chloride), and modified aliphatic polyamines (e.g., polyethylene polyamine).

[0076] Examples of anionic surfactants include sulfonic acid surfactants having a sulfonic acid group, sulfate ester surfactants having a sulfate ester group, and carboxylic acid surfactants having a carboxylic acid group. Examples of anionic surfactants include the compounds exemplified in paragraphs

[0116] to

[0123] of WO 2022 / 044893, the contents of which are incorporated herein by reference.

[0077] <Antifoaming Agent> The chemical solution may contain an antifoaming agent. Surfactants may cause foaming depending on how they are used. Therefore, it is preferable that a chemical solution containing a surfactant contains an antifoaming agent that suppresses the generation of foam, shortens the lifespan of the generated foam, and suppresses residual foam. The antifoaming agent is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof include silicone-based antifoaming agents, acetylene diol-based antifoaming agents, fatty acid ester-based antifoaming agents, and long-chain aliphatic alcohol-based antifoaming agents. Among these, silicone-based antifoaming agents are preferred because of their superior effect of suppressing residual foam. It should be noted that the antifoaming agent does not include compounds contained in the above-mentioned surfactants.

[0078] <Unsaturated Compound> The chemical solution may contain an unsaturated compound. The unsaturated compound is a compound containing a carbon-carbon unsaturated bond, preferably a compound containing a carbon-carbon double bond. The unsaturated compound preferably has at least one structure selected from the group consisting of a carboxylic acid group, an amide group, a hydroxy group, an ester bond, and an ether bond, and more preferably has at least one structure selected from the group consisting of a carboxylic acid group and a polyalkylene glycol structure. Examples of unsaturated compounds include unsaturated fatty acids such as linoleic acid, oleic acid, and sorbic acid, polyalkylene glycol alkenylene ethers such as polyoxyethylene oleyl ether, polyalkylene glycol unsaturated fatty acid esters such as polyethylene glycol oleate and polyethylene glycol linoleate, sorbitol unsaturated fatty acid esters such as sorbitol tetraoleate, sorbitol trioleate, sorbitol dioleate, and sorbitol monooleate, sorbitan unsaturated fatty acid esters such as sorbitan monooleate and sorbitan trioleate, oleamide, ethylene glycol monoallyl ether, allyl methyl ether, glycerol α,α'-diallyl ether, pentaerythritol tetraallyl ether, ethylene glycol monovinyl ether, maleic acid, 3-phenyl-2-propen-1-ol, and 1,2-epoxy-5-hexene.

[0079] The content of the unsaturated compound is preferably 0.001 to 10% by mass, more preferably 0.005 to 5% by mass, based on the total mass of the chemical solution.

[0080] [Physical Properties of Chemical Solution] <Turbidity> The turbidity of the chemical solution is preferably less than 10 NTU, and more preferably 0.01 or more and less than 10 NTU. Here, the turbidity of the chemical solution is determined by using a turbidity meter (TN-100IR, manufactured by Thermo Scientific) to measure the transmitted light (parallel light from an LED light source) attenuated by the turbidity substance and calculating the ratio to the incident light. Note that the formagine turbidity (NTU) is used as the unit of measurement for turbidity.

[0081] <pH> The pH of the chemical solution is preferably 0.5 to 9, more preferably 1 to 7. The pH of the chemical solution can be measured using a known pH meter by a method in accordance with JIS Z8802-1984. The measurement temperature is 25°C.

[0082] <Metal Content> The content (measured as ion concentration) of metals (e.g., 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 mass ppm or less, more preferably 1 mass ppm or less. In particular, the metal content is more preferably a value lower than 1 mass ppm, that is, a mass ppb order or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0083] <Insoluble Particles> The drug solution of the present invention preferably does not substantially contain insoluble particles. The term "insoluble particles" refers to particles of inorganic solids or organic solids that do not dissolve in the drug solution and ultimately exist as particles. The term "substantially does not contain insoluble particles" refers to a measurement composition obtained by diluting the drug solution 10,000 times with a solvent contained in the drug solution, and the number of particles with a particle size of 50 nm or more contained in 1 mL of the measurement composition is 40,000 or less. The number of particles contained in the measurement composition can be measured in the liquid phase using a commercially available particle counter. Commercially available particle counters include those manufactured by Rion and PMS. A representative example of the former is the KS-19F, and a representative example of the latter is the Chem20. To measure larger particles, devices such as the KS-42 series and LiQuilaz II S series can be used. Examples of insoluble particles include particles of inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and particles of organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. Methods for removing insoluble particles from the chemical solution include purification processes such as filtering. It is also preferable that the chemical solution does not contain abrasive grains.

[0084] <Coarse particles> The chemical solution may contain coarse particles, but the content thereof is preferably low. Coarse particles refer to particles having a diameter (particle size) of 1 μm or more when the particle shape is considered as a sphere. The coarse particles contained in the chemical solution include particles such as dust, dirt, organic solids, and inorganic solids contained as impurities in the raw material, as well as particles such as dust, dirt, organic solids, and inorganic solids brought in as contaminants during the preparation of the chemical solution, and which ultimately exist as particles without dissolving in the chemical solution.

[0085] The content of coarse particles in the chemical solution is preferably 100 or less, more preferably 50 or less, particles with a particle size of 1 μm or more per mL of the chemical solution. The lower limit is preferably 0 or more, more preferably 0.01 or more, per mL of the chemical solution. The content of coarse particles present in the chemical solution can be measured in the liquid phase using a commercially available measuring device that uses a light scattering liquid particle measuring method with a laser as a light source.

[0086] [Method for Producing the Chemical Solution] The chemical solution of the present invention can be produced by a known method.

[0087] [Solution Preparation Step] Examples of methods for preparing the chemical solution include a method of mixing the above-described components. The order and / or timing of mixing the above-described components are not particularly limited. For example, a method of sequentially adding an etchant compound, a cationic polymer, an anionic polymer, and, if necessary, optional components to a container containing a solvent, followed by stirring and mixing can be used. Alternatively, a pH adjuster can be added to adjust the pH of the mixed solution. When adding each component to a container, they may be added all at once or in multiple installments. In particular, a preferred method for preparing the chemical solution of the present invention is to prepare the chemical solution by adding a polymer with a low content to a precursor liquid containing a high content of the cationic polymer and anionic polymer contained in the chemical solution and not a low content of the polymer.

[0088] The stirring device and stirring method used to prepare the chemical solution may be a known device such as a stirrer or disperser. Examples of the stirrer include an industrial mixer, a portable stirrer, a mechanical stirrer, and a magnetic stirrer. Examples of the disperser include an industrial disperser, a homogenizer, an ultrasonic disperser, and a bead mill.

[0089] The mixing of the components in the chemical solution preparation step, the purification treatment described below, and storage of the produced chemical solution are preferably carried out at 40° C. or lower, more preferably at 30° C. or lower. The lower limit is preferably 5° C. or higher, more preferably 10° C. or higher. By preparing, treating, and / or storing the chemical solution within the above temperature range, the performance can be maintained stably for a long period of time.

[0090] The drug solution of the present invention may be prepared as a kit in which the raw materials are divided into a plurality of parts. When the drug solution of the present invention is prepared as a kit, the raw materials may be mixed in a predetermined ratio at the time of use or before use to obtain the drug solution of the present invention. The drug solution may also be prepared as a concentrated solution. In this case, the diluted solution obtained by diluting with a dilution liquid before use is used. In other words, the kit may include the drug solution in the form of a concentrated solution and the dilution liquid.

[0091] <Purification> It is preferable to perform a purification treatment in advance on one or more of the raw materials used to prepare the chemical solution. Furthermore, if necessary, the chemical solution may also be subjected to a purification treatment. The degree of purification is preferably such that the raw material has a purity of 99% by mass or more, and more preferably such that the purity of the raw solution has a purity of 99.9% by mass or more. The upper limit is preferably 99.9999% by mass or less.

[0092] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO membrane), reprecipitation, distillation of the raw material, and filtering. Any filter conventionally used for filtration can be used without particular limitations. Examples of materials constituting the filter include filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, polyallylsulfone (PAS), and polyolefin resins (including high-density or ultra-high molecular weight) such as polyethylene and polypropylene (PP). Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, with fluororesin filters being more preferred. Filtering the raw material using filters made of these materials effectively removes highly polar contaminants that are likely to cause defects.

[0093] The purification treatment may be carried out by combining two or more of the above purification methods, or may be carried out multiple times.

[0094] <Container> The container for containing the above-mentioned chemical solution, concentrated solution, or kit is not particularly limited, and known containers can be used as long as corrosiveness by the liquid is not a problem. Specific examples of the container include the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd. In addition, for the purpose of preventing impurities from being mixed (contaminated) into the raw materials and chemical solution, it is also preferable to use a multilayer container whose inner wall has a six-layer structure made of six types of resin, or a multilayer container whose inner wall has a seven-layer structure made of six types of resin. Examples of such containers include, but are not limited to, the containers described in JP 2015-123351 A. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of WO 2022 / 004217 can also be used as containers, and the contents of these containers are incorporated herein by reference.

[0095] The interior of these containers is preferably washed before filling them with the chemical solution. The liquid used for washing is preferably one that has a reduced amount of metal impurities. After production, the chemical solution may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored.

[0096] To prevent changes in the components of the drug solution during storage, the container may be filled with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. A gas with a low water content is particularly preferred. During transportation and storage, the drug solution may be stored at room temperature, or the temperature may be controlled within the range of -20°C to 20°C to prevent deterioration.

[0097] The method for producing the chemical solution may further include a static elimination step of eliminating static electricity from the chemical solution.

[0098] [Uses] The chemical solution of the present invention is used for processing semiconductor substrates. More specifically, it is preferably used for semiconductor devices. "For semiconductor devices" means that it is used during the manufacture of semiconductor devices. The chemical solution can be used in the manufacturing process of semiconductor devices, for example, to process SiOCN-containing materials, SiGe-containing materials, Si-containing materials, insulating films, resist films, anti-reflective films, etching residues, and ashing residues (hereinafter simply referred to as "residues") present on a substrate. The chemical solution may also be used for processing semiconductor substrates after chemical mechanical polishing. The chemical solution of the present invention is preferably applied to substrates containing at least one of SiOCN-containing materials and SiGe-containing materials, and more preferably applied to substrates containing both SiOCN-containing materials and SiGe-containing materials. Therefore, the chemical solution of the present invention can be suitably used as a liquid (etchant) for removing at least a portion of the SiGe-containing materials from a workpiece containing SiOCN-containing materials and SiGe-containing materials.

[0099] [Method for Manufacturing a Semiconductor Device] The method for manufacturing a semiconductor device of the present invention uses the chemical solution of the present invention described above. Specifically, a preferred method is to contact the chemical solution of the present invention with a substrate having SiOCN-containing materials and SiGe-containing materials (hereinafter simply referred to as "workpiece"). By contacting the workpiece with the chemical solution, the etching ability of the SiOCN-containing materials in the workpiece is suppressed, and the SiGe-containing materials in the workpiece are selectively removed (etched). Methods for contacting the workpiece with the chemical solution include, for example, immersing the workpiece in the chemical solution contained in a tank, spraying the chemical solution on the workpiece, flowing the chemical solution on the workpiece, and combinations of these methods. Preferably, the method involves immersing the workpiece in the chemical solution.

[0100] The treatment time for contacting the chemical solution can be adjusted as appropriate. The treatment time (contact time between the chemical solution and the object to be treated) is preferably 0.5 to 60 minutes, more preferably 1 to 20 minutes. The temperature of the chemical solution during treatment is preferably 10 to 100°C, more preferably 15 to 60°C.

[0101] The method for manufacturing a semiconductor device of the present invention may include other process steps in addition to the chemical contact process, such as formation steps (e.g., layer formation, etching, chemical mechanical polishing, and modification) of structures such as metal wiring, gate structures, source structures, drain structures, insulating films, ferromagnetic layers, and non-magnetic layers, as well as resist formation, exposure, and removal steps, heat treatment, cleaning, and inspection steps.

[0102] The above processing method may be performed at any stage of the back end process (BEOL: Back end of the line), middle process (MOL: Middle of the line), or front end process (FEOL: Front end of the line), and is preferably performed in the front end process or middle process.

[0103] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the examples shown below. Furthermore, all of the components used in the examples and comparative examples were classified as semiconductor grade or equivalent high purity grade.

[0104] Examples 1 to 8 and Comparative Examples 1 to 7 Preparation of Chemical Solutions Of the components listed in Tables 1 and 2 below, acetic acid, hydrogen peroxide, sulfuric acid, and water were added to give the values ​​shown in Tables 1 and 2 below, and the mixture was stirred for 68 hours. Next, a cationic polymer (cationic compound in the Comparative Examples), an anionic polymer (anionic compound in the Comparative Examples), hydrogen fluoride, and water were added in this order to give the values ​​shown in Tables 1 and 2 below, thereby preparing the chemical solutions of each Example and Comparative Example. The components used in preparing the chemical solutions are as follows:

[0105] <Anionic polymers, etc.> Anionic polymer 1: Naphthalenesulfonic acid formalin condensate Na (Takesurf A-45-K, weight average molecular weight: 1300, manufactured by Takemoto Oil Co., Ltd.) Anionic polymer 2: Naphthalenesulfonic acid formalin condensate (Takesurf A-47-Q, weight average molecular weight: 1800, manufactured by Takemoto Oil Co., Ltd.) Anionic polymer 3: Poly(styrenesulfonic acid) (weight average molecular weight: 75000, manufactured by Wako Chemical Co., Ltd.) Anionic compound H1: Sodium alkyldiphenylether disulfonate (Pelex SS-H, manufactured by Kao Corporation) Anionic compound H2: p-toluenesulfonic acid (PTSA, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Anionic compound H3: Dodecylbenzenesulfonic acid (soft type) (purchased from Tokyo Chemical Industry Co., Ltd.)

[0106] <Cationic polymers and the like> Cationic polymer 1: Polyquaternium-51 (Lipidure (registered trademark) PMB, weight average molecular weight: 600,000, manufactured by NOF Corporation) Cationic polymer 2: Diallylmethylethylammonium ethyl sulfate-sulfur dioxide copolymer (PAS-2401, weight average molecular weight: 2,000, manufactured by Nittobo Medical Co., Ltd.) Cationic polymer 3: Diallyldimethylammonium chloride-maleic acid copolymer (PAS-2351, weight average molecular weight: 25,000, manufactured by Nittobo Medical Co., Ltd.) Cationic polymer 4: Poly(diallyldimethylammonium chloride) (PAS-H-1L, weight average molecular weight: 8,500, manufactured by Nittobo Medical Co., Ltd.) Cationic compound H1: N-(3-aminopropyl)diethanolamine (purchased from Tokyo Chemical Industry Co., Ltd.)

[0107] <Other ingredients> Hydrogen fluoride (fluoride ion source) Hydrogen peroxide (oxidizing agent, standard redox potential 1.8 V) Acetic acid (solvent) Sulfuric acid (acidic compound) Water (solvent)

[0108] [Evaluation] [Solubility] For each of the prepared chemical solutions, the SiGe-containing material, the Si-containing material, and the SiO ２ The solubility of the inclusions and SiOCN inclusions was evaluated according to the following criteria.

[0109] Specifically, first, a substrate on which silicon germanium (Si:Ge=75:25 (element ratio)) is laminated to a thickness of 50 nm, a substrate on which polysilicon (Si) is laminated to a thickness of 100 nm, and a substrate on which silicon oxide (SiO ２ A substrate on which a 100 nm thick SiGe film, a Si film, and a 100 nm thick silicon oxycarbon nitride (SiOCN) film were laminated was prepared, and each of these substrates was cut into a 2×2 cm square to prepare a test specimen. The test specimen was immersed in the chemical solution (25° C.) of the example or comparative example for 2 minutes. Before and after the immersion test, the SiGe film, the Si film, and the SiO ２The film thicknesses of the SiGe film and the SiOCN film were measured using an optical film thickness meter, Ellipsometer M-2000 (manufactured by J.A. Woollam). The dissolution rate (Å / min) of each film when using each treatment liquid was calculated from the measured film thickness before and after immersion. The solubility of each film in each treatment liquid was evaluated based on the calculated dissolution rate of each film, according to the following evaluation criteria. The results are shown in Tables 1 and 2 below. Note that if the evaluation criteria for solubility in a SiGe film are A and the evaluation criteria for solubility in a SiOCN film are A, it can be said that the etching ability for SiOCN-containing materials is suppressed and the etching ability for SiGe-containing materials is good. <Evaluation criteria for solubility in SiGe film> A: Dissolution rate is 30 Å / min or more B: Dissolution rate is 5 Å / min or more but less than 30 Å / min C: Dissolution rate is less than 5 Å / min <Evaluation criteria for solubility in Si film> A: Dissolution rate is less than 7 Å / min B: Dissolution rate is 7 Å / min or more but less than 15 Å / min C: Dissolution rate is 15 Å / min or more <SiO ２ Evaluation criteria for solubility in film> A: Dissolution rate less than 2 Å / min B: Dissolution rate 2 Å / min or more but less than 6 Å / min C: Dissolution rate 6 Å / min or more <Evaluation criteria for solubility in SiOCN film> A: Dissolution rate less than 0.1 Å / min B: Dissolution rate 0.1 Å / min or more but less than 0.5 Å / min C: Dissolution rate 0.5 Å / min or more

[0110] [Turbidity] The turbidity of each prepared chemical solution was measured by the method described above and evaluated according to the following criteria. The results are shown in Tables 1 and 2 below. <Evaluation criteria> A: Turbidity less than 5 NTU B: Turbidity 5 NTU or more but less than 10 NTU C: Turbidity 10 NTU or more

[0111]

[0112]

[0113] From the results shown in Tables 1 and 2 above, it was found that chemical solutions in which the content X of the cationic polymer relative to the total mass of the chemical solution and the content Y of the anionic polymer relative to the total mass of the chemical solution did not satisfy either of the following formulas (1) and (2) could not suppress the etching ability for SiOCN-containing materials or had high turbidity (Comparative Examples 1 to 7). Formula (1) 6≦Y / X Formula (2) 6≦X / Y

[0114] In contrast, it was found that a chemical solution in which the content X of the cationic polymer relative to the total mass of the chemical solution and the content Y of the anionic polymer relative to the total mass of the chemical solution satisfy the above formula (1) or (2) has low turbidity, suppresses etching properties for SiOCN-containing materials, and exhibits good etching properties for SiGe-containing materials (Examples 1 to 8).

Claims

1. A chemical solution containing an etchant compound, a cationic polymer, and an anionic polymer, wherein when the content of the cationic polymer relative to the total mass of the chemical solution is content X and the content of the anionic polymer relative to the total mass of the chemical solution is content Y, the chemical solution satisfies the relationship of the following formula (1) or (2): Formula (1) 6≦Y / X Formula (2) 6≦X / Y 2. The chemical solution according to claim 1, wherein the content of the anionic polymer is 0.0001 to 0.03% by mass based on the total mass of the chemical solution.

3. The chemical solution according to claim 1, wherein the content of the cationic polymer is 0.01 to 0.05% by mass relative to the total mass of the chemical solution.

4. The chemical solution according to claim 1, wherein the anionic polymer has acidic groups capable of dissociating in the chemical solution by 1% or more.

5. The drug solution according to claim 1, wherein the anionic polymer has at least one group selected from the group consisting of a sulfonic acid group, a phosphonic acid group, and a carboxylic acid group.

6. The medicinal solution according to claim 1, wherein the cationic polymer has at least one group selected from the group consisting of a tertiary amino group and a quaternary ammonium salt group.

7. The drug solution according to claim 1, wherein the cationic polymer has a quaternary ammonium salt group.

8. The chemical solution of claim 1, wherein the etchant compound comprises a source of fluoride ions.

9. The chemical solution of claim 1, further comprising an oxidizing agent.

10. The chemical solution according to claim 9, wherein the content of the oxidizing agent is 0.01 to 10 mass % based on the total mass of the chemical solution.

11. The chemical solution of claim 1 applied to a substrate having silicon oxycarbonitride inclusions.

12. The chemical solution of claim 1 applied to a substrate having silicon germanium inclusions.

13. The chemical solution of claim 1 applied to a substrate having silicon oxycarbonitride content and silicon germanium content.

14. A method for producing a chemical solution according to any one of claims 1 to 13, comprising adding a polymer with a low content to a precursor liquid that contains a polymer with a high content and does not contain a polymer with a low content of cationic polymer and anionic polymer contained in the chemical solution, to prepare the chemical solution.

15. A method for manufacturing a semiconductor device, using the chemical solution according to any one of claims 1 to 13.

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